Osteochondrosis

Complex MONDO:0018381 Pathograph 18 Show in embeddings browser Osteonecrosis Bone disease

Osteochondrosis is a group of disorders of growing bone in which disturbance of endochondral ossification at an epiphysis or apophysis leads to necrosis, fragmentation, and subsequent repair/remodeling. MONDO places the term as a child of osteonecrosis (osteochondrosis "not specified as adult or juvenile, of unspecified site"), but the classical (Siffert) nosology in fact splits the family into three mechanistically distinct groups, which this entry models as three separate pathophysiology chains rather than one lumped cascade: (1) an articular/epiphyseal group in which cartilage-canal vessel failure causes true ischemic chondronecrosis (Legg-Calve-Perthes disease, Kohler disease, Freiberg infraction, and osteochondritis dissecans); (2) a non-articular apophyseal group driven by repetitive tensile traction at a tendon insertion, not primary ischemia (Osgood-Schlatter disease, Sever disease); and (3) a physeal/endplate group driven by compressive growth-cartilage failure at the vertebral ring apophysis (Scheuermann kyphosis). Only the first group is truly ischemic/necrotic; the apophyseal and physeal groups are grouped with osteochondrosis by clinical convention (shared growing-bone, self-limited-then-remodeling phenotype) rather than by a shared vascular mechanism. Kohler disease is already curated as its own dismech entry (kb/disorders/Osteochondritis_of_Tarsal_Metatarsal_Bone.yaml, MONDO:0016086) and is cross-referenced here by name rather than duplicated.

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7
Pathophys.
9
Phenotypes
2
Gaps
18
Pathograph
4
Genes
4
Medical Actions
7
Subtypes
1
Trials
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Deep Research
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Subtypes

7
Legg-Calve-Perthes Disease (Femoral Head) MONDO:0007885
Autosomal dominant inheritance
Idiopathic juvenile osteonecrosis of the femoral head, the prototypical and most-studied member of the articular/epiphyseal osteochondrosis family. Reported prevalence ranges from 0.4 to 29.0 per 100,000 children under 15 years of age, with a peak incidence between 4 and 8 years and a male predominance. Etiology remains debated: mechanically induced ischemia of the capital femoral epiphysis is the best-supported theory, with additional evidence for a thrombotic/coagulation component and, rarely, a Mendelian type II collagenopathy phenocopy (COL2A1).
Show evidence (1 reference)
PMID:30918798 SUPPORT Human Clinical
"Its prevalence is set to be between 0.4/100000 to 29.0/100000 children less than 15 years of age with a peak of incidence in children aged from 4 years to 8 years."
Systematic review reporting the population prevalence range and peak age of onset for Legg-Calve-Perthes disease.
Osgood-Schlatter Disease (Tibial Tuberosity) MONDO:0004241
Traction apophysitis of the tibial tuberosity, the prototypical member of the non-articular apophyseal osteochondrosis family. It is the most common knee osteochondrosis in sport-practicing children and adolescents, with reported prevalence around 9.8% and bilateral involvement in 20-30% of affected individuals. Onset coincides with appearance of the tibial tuberosity secondary ossification center and is linked to sports with an explosive/jumping component; the mechanism is repetitive tensile traction at the patellar tendon insertion rather than primary ischemia.
Show evidence (1 reference)
PMID:35740763 SUPPORT Human Clinical
"The prevalence of OD is 9.8%, and it can be bilateral in 20–30% of patients"
Systematic review reporting population prevalence and rate of bilateral involvement for Osgood-Schlatter disease.
Sever Disease (Calcaneal Apophysis)
Traction apophysitis of the calcaneal apophysis at the Achilles tendon insertion, the second member of the non-articular apophyseal family. No MONDO term currently exists for this concept (OLS/Ontobee search returns no MONDO hit), so this subtype is modeled with a free-text `subtype_term.preferred_term` only. It is a common cause of heel pain in children and young athletes aged 8 to 15 with immature skeletons, arising from repetitive microtrauma to the secondary ossification center by traction of the Achilles tendon insertion, often compounded by triceps-surae tightness from a growth-rate mismatch between bone and muscle-tendon length.
Show evidence (1 reference)
PMID:28722957 SUPPORT Human Clinical
"Sever disease results from repetitive microtrauma to the secondary ossification center by traction of the Achilles tendon insertion on the calcaneus."
Establishes the traction-apophysitis mechanism and anatomic site for Sever disease.
Kohler Disease (Navicular) MONDO:0016086
Ischemic osteochondrosis of the tarsal navicular, a member of the articular/epiphyseal family. Curated as its own dismech entry — see kb/disorders/Osteochondritis_of_Tarsal_Metatarsal_Bone.yaml for full phenotype, evidence, and treatment content (which also disambiguates it from adult Muller-Weiss disease and from Freiberg disease). Included here only for completeness of the site-based osteochondrosis subtype list; not duplicated.
Freiberg Infraction (Second Metatarsal Head) MONDO:0023188
Ischemic osteochondrosis of the second metatarsal head, a member of the articular/epiphyseal family. It is the fourth most common form of primary osteochondrosis, with a strong predilection for adolescent athletic females, though it has been reported across a wide age range. Like other members of the articular family it is generally self-limited when treated early, resolving with nonoperative management.
Show evidence (1 reference)
PMID:30685014 SUPPORT Human Clinical
"Freiberg disease is characterized as osteochondrosis of the second metatarsal head. It is the fourth most common form of primary osteochondrosis with a significant predilection to the adolescent athletic female population"
Defines the anatomic site and relative frequency/demographic predilection of Freiberg disease among the primary osteochondroses.
Scheuermann Kyphosis (Vertebral Ring Apophyses) MONDO:0008410
Structural thoracic kyphosis of the physeal/endplate osteochondrosis family, diagnosed radiographically by Sorensen's criteria (at least three consecutive vertebrae wedged by five degrees or more at the apex of the deformity). Population prevalence is approximately 2.8% (2.1% in women, 3.6% in men), and a Danish twin-registry study estimated heritability at 74%, indicating a major genetic contribution distinct from the primarily biomechanical apophyseal family. Unlike Legg-Calve-Perthes disease, Osgood-Schlatter disease, and Sever disease, this subtype is not driven by vascular ischemia or tendon traction but by compressive failure of the cartilaginous vertebral endplate and ring apophysis.
Show evidence (2 references)
PMID:17015588 SUPPORT Human Clinical
"the overall prevalence of Scheuermann disease was 2.8%, with a prevalence of 2.1% among women and 3.6% among men"
Danish Twin Registry study establishing population prevalence and sex distribution of Scheuermann kyphosis.
PMID:17015588 SUPPORT Human Clinical
"These differences were significant (p < 0.01). Heritability was 74%."
Reports the heritability estimate that distinguishes Scheuermann kyphosis from the mechanically-dominant apophyseal osteochondroses.
Osteochondritis Dissecans (Articular Surface) MONDO:0017178
Autosomal dominant inheritance
Acquired focal lesion of subchondral bone and overlying articular cartilage, most commonly of the knee, elbow, or ankle, that can progress to a detached osteochondral fragment (loose body) and secondary osteoarthritis. Experimental (foal) and human cadaveric/CT-histology studies support the same ischemic-chondronecrosis mechanism as the rest of the articular osteochondrosis family: failure of epiphyseal cartilage-canal blood supply causes focal chondronecrosis and a delay in endochondral ossification (osteochondrosis), which can subsequently progress to pathological cartilage fracture (osteochondritis dissecans).
Show evidence (2 references)
PMID:34109940 SUPPORT Human Clinical
"Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis."
Establishes the demographic pattern, anatomic sites, and long-term consequence (premature osteoarthritis) of osteochondritis dissecans.
PMID:34109940 SUPPORT Human Clinical
"various etiopathogenetic theories are being investigated, including local ischemia, aberrant endochondral ossification of the secondary subarticular physis, repetitive microtrauma, and genetic predisposition"
Confirms local ischemia and aberrant endochondral ossification as leading etiopathogenetic theories for osteochondritis dissecans, consistent with the articular osteochondrosis mechanism.
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Discussions and Knowledge Gaps

2
Does the ischemic-chondronecrosis mechanism, reproduced causally in foals and other model organisms, generalize to all sites and severities of human articular osteochondrosis, or only to the specific predilection sites and ages examined so far?
HUMAN MODEL MISMATCH OPEN osteochondrosis_animal_ischemia_human_translation
Attached to
pathophysiology#Cartilage-Canal Ischemic Chondronecrosis
The causal experiment for cartilage-canal vessel failure -> ischemic chondronecrosis -> osteochondrosis -> osteochondrosis dissecans was performed by surgically transecting vessels in the femoro-patellar joint of foals (PMID:23428601), an equine model with different growth-plate biology, cartilage-canal anatomy, and loading regime than the pediatric human knee/hip/foot. The strongest human bridging evidence (PMID:30248503) is limited to CT/histology of pediatric knee predilection sites in cadaveric/postmortem specimens (13 children, 1 month to 11 years old), not living-patient longitudinal data, and to the knee specifically rather than the hip (Perthes), navicular (Kohler), or metatarsal head (Freiberg) sites also attributed to this mechanism.
Proposed experiments
Multi-site human cartilage-canal histology across the articular osteochondrosis family
exp_osteochondrosis_multisite_human_histology
Extend the pediatric-knee CT/histology approach (PMID:30248503) to cadaveric or surgical specimens from the femoral head, tarsal navicular, and second metatarsal head predilection sites, at ages spanning the typical clinical onset for Perthes, Kohler, and Freiberg disease respectively, to test whether the same ischemic-chondronecrosis signature is present at each site.
Show evidence (1 reference)
PMID:23428601 SUPPORT Model Organism
"There are several similarities between OCD in animals and JOCD in children. It should be investigated whether JOCD also occurs due to a focal failure in the cartilage canal blood supply, followed by ischaemic chondronecrosis."
The authors themselves frame the human translation as a question still to be investigated at the time of publication, not an established fact.
Is mechanically induced ischemia sufficient to explain Legg-Calve-Perthes disease, or does the disease require an additional predisposing factor (thrombophilic, genetic, or environmental) in most cases?
KNOWLEDGE GAP OPEN perthes_etiology_undetermined
Attached to
pathophysiology#Cartilage-Canal Ischemic Chondronecrosis
A systematic review of 64 articles on LCPD etiology found no single decisive theory: mechanically induced ischemia is the best-supported, twin studies argue against a major role for common genetic factors, and a congenital or acquired predisposition cannot be excluded. This entry therefore models the thrombophilia (F5/F2), Mendelian COL2A1 phenocopy, and secondhand-smoke environmental associations as contributing risk factors rather than as components of a single confirmed causal chain.
Show evidence (1 reference)
PMID:30918798 SUPPORT Human Clinical
"Several hypotheses have been researched, but none of them was found decisive."
States directly that no single etiologic hypothesis for LCPD has been established as decisive.
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Pathophysiology

7
Cartilage-Canal Ischemic Chondronecrosis
In the articular/epiphyseal osteochondrosis family, blood vessels running through cartilage canals supply the secondary (epiphyseal) ossification center during growth. Focal failure or transection of these vessels causes ischemic necrosis of chondrocytes and vascular endothelium in the epiphyseal cartilage, before any bone is yet mineralized at that site. This mechanism was reproduced experimentally by surgically transecting cartilage-canal vessels in foals, and morphologically identical lesions (confirmed by histology to represent cartilage-canal blood-supply failure and ischemic chondronecrosis) were subsequently identified at the predilection sites for juvenile osteochondritis dissecans in human pediatric knee specimens.
Chondrocyte CL:0000138 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Chondrocyte (CL:0000138). CL:0000138 is a cell type from the Cell Ontology. Growth plate cartilage chondrocyte CL:1000217 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Growth plate cartilage chondrocyte (CL:1000217). CL:1000217 is a cell type from the Cell Ontology.
Response to hypoxia (cartilage-canal ischemia) GO:0001666 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Response to hypoxia (cartilage-canal ischemia), annotated with response to hypoxia (GO:0001666). GO:0001666 is a biological process from the Gene Ontology. Chondrocyte and vascular endothelial cell death GO:0008219 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased Chondrocyte and vascular endothelial cell death, annotated with cell death (GO:0008219). GO:0008219 is a biological process from the Gene Ontology. ↑ INCREASED
Epiphyseal cartilage canal UBERON:0001437 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in Epiphyseal cartilage canal, annotated with epiphysis (UBERON:0001437). UBERON:0001437 is an anatomical location from the Uberon multi-species anatomy ontology. Subchondral region of epiphysis UBERON:0035878 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in Subchondral region of epiphysis (UBERON:0035878). UBERON:0035878 is an anatomical location from the Uberon multi-species anatomy ontology.
Downstream
Delayed Endochondral Ossification and Necrotic Fragmentation Ischemic chondronecrosis produces a focal delay in endochondral ossification at the affected site; if loading continues before ossification and repair catch up, the necrotic/weakened cartilage-bone interface is prone to structural collapse and fragmentation.
Show evidence (2 references)
PMID:23428601 SUPPORT Model Organism
"Transection of blood vessels within epiphyseal cartilage canals resulted in necrosis of vessels and chondrocytes, i.e., ischaemic chondronecrosis, in foals."
Causal experimental evidence (surgical vessel transection) directly demonstrating that cartilage-canal vascular failure produces ischemic chondronecrosis, the initiating lesion of the articular osteochondrosis family.
PMID:30248503 SUPPORT Human Clinical
"Changes identical to osteochondrosis in animals were detected at predilection sites for JOCD in children, and confirmed to represent failure of the cartilage canal blood supply and ischemic chondronecrosis in histological sections."
Human pediatric CT/histology study translating the animal-model ischemic-chondronecrosis mechanism to human juvenile osteochondritis dissecans predilection sites.
Delayed Endochondral Ossification and Necrotic Fragmentation
The necrotic, unossified cartilage/subchondral bone segment fails to bear load normally. Continued mechanical loading of the affected epiphysis or subarticular bone (e.g., the immature femoral head in Perthes disease, or the second metatarsal head in Freiberg infraction) leads to increased bone resorption relative to delayed new bone formation, producing structural weakening, collapse, sclerosis, flattening, and fragmentation on imaging. In the most severe articular presentations this culminates in pathological cartilage fracture and, in osteochondritis dissecans, a detached osteochondral fragment (loose body).
Delayed endochondral ossification GO:0001958 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased Delayed endochondral ossification, annotated with endochondral ossification (GO:0001958). GO:0001958 is a biological process from the Gene Ontology. ↓ DECREASED Bone resorption GO:0045453 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased Bone resorption (GO:0045453). GO:0045453 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Revascularization and Remodeling under Mechanical Load Necrotic tissue is progressively removed and replaced by vascularized granulation tissue and new bone (creeping substitution), which under continued mechanical load can restore structural integrity or, if loading outpaces repair, leave residual deformity.
Show evidence (2 references)
PMID:22488623 SUPPORT Human Clinical
"the immature femoral head is mechanically weakened following ischemic necrosis. Increased bone resorption and delayed new bone formation, in combination with continued mechanical loading of the hip, contribute to the pathogenesis of the femoral head deformity."
Establishes the resorption/formation imbalance and role of continued mechanical loading in producing structural deformity after ischemic necrosis, generalizing across the articular osteochondrosis family.
PMID:34109940 SUPPORT Human Clinical
"Treatment largely depends on skeletal maturity and lesion stability, defined by the presence or absence of articular cartilage fracture and subchondral bone separation, as determined by imaging and arthroscopy"
Confirms cartilage fracture and subchondral bone separation as the structural endpoints that distinguish stable from unstable osteochondritis dissecans lesions.
Revascularization and Remodeling under Mechanical Load
The articular osteochondrosis family is characteristically self-limited: revascularization delivers chondroclasts/osteoclasts and granulation tissue that remove necrotic tissue while new bone formation proceeds, under the influence of ongoing mechanical loading of the growing epiphysis. Outcome depends on the balance between repair and load — a spherical, congruent joint surface if repair keeps pace, or residual flattening/ deformity and premature secondary osteoarthritis if mechanical failure outpaces repair.
Sprouting angiogenesis GO:0002040 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Sprouting angiogenesis (GO:0002040). GO:0002040 is a biological process from the Gene Ontology. Bone remodeling GO:0046849 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Bone remodeling (GO:0046849). GO:0046849 is a biological process from the Gene Ontology.
Show evidence (2 references)
PMID:30248503 SUPPORT Human Clinical
"Intra-cartilaginous secondary responses comprising proliferation of adjacent chondrocytes and vessels were detected in six and two lesions, whereas intra-osseous responses including accumulation of chondroclasts and formation of granulation tissue occurred in 10 and six lesions, respectively."
Human histological evidence for the revascularization/repair response (chondrocyte and vessel proliferation, chondroclast accumulation, granulation tissue formation) that follows ischemic chondronecrosis.
PMID:30685014 SUPPORT Human Clinical
"If treated early, osteochondroses such as Freiberg disease are essentially self-limiting, often resolving with nonoperative management."
Supports the self-limited, load-dependent repair course that characterizes the articular osteochondrosis family when caught early.
Repetitive Traction Apophysitis
In the non-articular apophyseal osteochondrosis family, the mechanism is NOT primary ischemia. A traction apophysis is a secondary ossification center at a tendon insertion (the tibial tuberosity for the patellar tendon in Osgood-Schlatter disease; the calcaneal apophysis for the Achilles tendon in Sever disease). Repetitive, forceful traction from running/jumping sports during a rapid growth spurt — often compounded by relative muscle-tendon tightness outpacing bone growth — causes chronic microtrauma, inflammation, and disordered ossification at the unfused apophysis, distinct from the ischemic mechanism of the articular family.
Response to mechanical stimulus (tendon traction) GO:0009612 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Response to mechanical stimulus (tendon traction), annotated with response to mechanical stimulus (GO:0009612). GO:0009612 is a biological process from the Gene Ontology. Endochondral ossification (secondary ossification center) GO:0001958 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves dysregulated Endochondral ossification (secondary ossification center), annotated with endochondral ossification (GO:0001958). GO:0001958 is a biological process from the Gene Ontology. ↕ DYSREGULATED
Tibial tuberosity UBERON:7500062 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in Tibial tuberosity (UBERON:7500062). UBERON:7500062 is an anatomical location from the Uberon multi-species anatomy ontology. Calcaneal apophysis UBERON:0001450 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in Calcaneal apophysis, annotated with calcaneus (UBERON:0001450). UBERON:0001450 is an anatomical location from the Uberon multi-species anatomy ontology. Calcaneal (Achilles) tendon insertion UBERON:0003701 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in Calcaneal (Achilles) tendon insertion, annotated with calcaneal tendon (UBERON:0003701). UBERON:0003701 is an anatomical location from the Uberon multi-species anatomy ontology.
Downstream
Apophyseal Pain, Prominence, and Fragmentation Chronic traction produces local pain, swelling, and, radiographically, irregularity or fragmentation of the apophysis, without the true ischemic necrosis seen in the articular family.
Show evidence (2 references)
PMID:35740763 SUPPORT Human Clinical
"It often results from acute or chronic overload during sports activity, causing inflammation of the patellar tendon insertion on the tibial tuberosity"
Establishes the traction/overload mechanism, distinct from ischemia, at the tibial tuberosity apophysis in Osgood-Schlatter disease.
PMID:28722957 SUPPORT Human Clinical
"The condition frequently coincides with triceps surae shortening, which stems from the difference in growth rates between bone and muscle."
Establishes the growth-rate-mismatch/tightness contributor to traction apophysitis at the calcaneal apophysis in Sever disease.
Apophyseal Pain, Prominence, and Fragmentation
The end-stage clinical/radiographic phenotype of traction apophysitis: localized pain and swelling that worsen with activity and improve with rest, sometimes with a palpable bony prominence, and self-resolution once the apophysis fuses at the end of skeletal growth.
Show evidence (1 reference)
PMID:28722957 SUPPORT Human Clinical
"Patients affected by Sever disease usually report pain resolution during periods of rest or when the growth plate fully closes."
Confirms the self-limited, growth-plate-fusion-dependent resolution pattern characteristic of the apophyseal osteochondrosis family.
Compressive Vertebral Endplate Growth Failure
In the physeal/endplate osteochondrosis family, excessive mechanical (compressive) loading impairs growth of the cartilaginous vertebral endplate and ring apophysis at the thoracic spine, distinct from both the ischemic mechanism of the articular family and the tensile-traction mechanism of the apophyseal family. This is associated with Schmorl's node formation (nucleus pulposus herniation through a weakened endplate), disruption of the ring apophysis, and compromised intervertebral disc integrity. A shortened sternum has also been proposed to increase anterior compressive force on the vertebral endplates, though this remains a single-study hypothesis.
Growth plate cartilage development (vertebral endplate) GO:0003417 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased Growth plate cartilage development (vertebral endplate), annotated with growth plate cartilage development (GO:0003417). GO:0003417 is a biological process from the Gene Ontology. ↓ DECREASED Response to mechanical stimulus (compressive loading) GO:0009612 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Response to mechanical stimulus (compressive loading), annotated with response to mechanical stimulus (GO:0009612). GO:0009612 is a biological process from the Gene Ontology.
Vertebral ring apophysis / endplate UBERON:0002347 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in Vertebral ring apophysis / endplate, annotated with thoracic vertebra (UBERON:0002347). UBERON:0002347 is an anatomical location from the Uberon multi-species anatomy ontology. Vertebral growth plate cartilage UBERON:0004129 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in Vertebral growth plate cartilage, annotated with growth plate cartilage (UBERON:0004129). UBERON:0004129 is an anatomical location from the Uberon multi-species anatomy ontology.
Downstream
Anterior Vertebral Wedging and Kyphotic Deformity Uneven anterior-versus-posterior vertebral body growth under compression produces the characteristic wedge-shaped vertebral bodies and rigid thoracic hyperkyphosis diagnostic of Scheuermann kyphosis.
Show evidence (2 references)
PMID:41594596 SUPPORT Human Clinical
"excessive mechanical loading as a major contributor to defective growth of the cartilaginous vertebral endplate. This is associated with the formation of Schmorl's nodes, disruption of the ring apophysis, and compromised intervertebral disc integrity"
Current review establishing compressive mechanical loading of the cartilaginous vertebral endplate, rather than ischemia or tendon traction, as the physeal-family mechanism.
PMID:18165737 SUPPORT Human Clinical
"the smaller length of sternum than the normal has a possible correlation with the appearance of Scheuermann disease. Probably the smaller length of sternum increases the compressive forces on the vertebral endplates anteriorly, allowing uneven growth of the vertebral bodies with wedging."
Single cohort study (10,057 screened students) proposing a specific biomechanical contributor (short sternum) to endplate compressive failure; treated as partial/hypothesis-level support given the authors' own hedged language and the absence of independent replication.
Anterior Vertebral Wedging and Kyphotic Deformity
Radiographically defined by Sorensen's criteria (at least three consecutive vertebrae wedged five degrees or more at the apex), accompanied by irregular endplates, decreased disc height, and Schmorl's nodes, producing a rigid dorsal kyphosis that may be accompanied by pain and cosmetic complaints.
Show evidence (1 reference)
PMID:41594596 SUPPORT Human Clinical
"These require at least three consecutive vertebrae wedged by five degrees or more at the apex of the deformity, resulting in thoracic hyperkyphosis"
States the Sorensen radiographic diagnostic criteria that define the wedged-vertebra/kyphosis endpoint of the physeal osteochondrosis family.
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Pathograph

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Pathograph: causal mechanism network for Osteochondrosis Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

9
Musculoskeletal 2
Thoracic Hyperkyphosis with Vertebral Wedging HP:0002808 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Kyphosis (HP:0002808). HP:0002808 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:41594596 SUPPORT Human Clinical
"It presents as a rigid kyphotic deformity, often accompanied by pain and cosmetic complaints, and is diagnosed based on the radiographic criteria established by Sørensen in 1964"
Describes the clinical presentation and radiographic diagnostic basis of Scheuermann kyphosis.
Premature Secondary Osteoarthritis Premature osteoarthritis HP:0003088 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Premature osteoarthritis (HP:0003088). HP:0003088 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:22488623 SUPPORT Human Clinical
"Legg-Calvé-Perthes disease is a juvenile form of idiopathic osteonecrosis of the femoral head that can lead to permanent femoral head deformity and premature osteoarthritis."
Identifies premature osteoarthritis as a long-term consequence of Legg-Calve-Perthes disease.
PMID:34109940 SUPPORT Human Clinical
"Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis."
Identifies premature osteoarthritis as a long-term consequence of unresolved osteochondritis dissecans lesions.
Other 7
Hip Pain and Limp HP:0030838 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hip pain (HP:0030838). HP:0030838 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:22488623 SUPPORT Human Clinical
"Legg-Calvé-Perthes disease is a juvenile form of idiopathic osteonecrosis of the femoral head that can lead to permanent femoral head deformity and premature osteoarthritis."
Establishes the clinical identity and femoral-head site underlying the hip pain/limp presentation.
Avascular Necrosis of the Capital Femoral Epiphysis HP:0005743 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Avascular necrosis of the capital femoral epiphysis (HP:0005743). HP:0005743 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:17394019 SUPPORT Human Clinical
"Legg-Calvé-Perthes disease (LCPD) is a common childhood hip disorder characterized by sequential stages of involvement of the capital femoral epiphyses, including subchondral fracture, fragmentation, re-ossification and healing with residual deformity."
Describes the staged avascular-necrosis-to-healing sequence at the capital femoral epiphysis.
Anterior Knee Pain over the Tibial Tuberosity HP:0030839 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Knee pain (HP:0030839). HP:0030839 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:35740763 SUPPORT Human Clinical
"insidious onset (usually atraumatic) of anterior functional knee pain over the tibial tuberosity along with a bony prominence, as well as tenderness at the patellar tendon insertion site"
Describes the characteristic clinical presentation of Osgood-Schlatter disease.
Heel Pain Foot pain HP:0025238 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Heel pain, annotated with Foot pain (HP:0025238). HP:0025238 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:28722957 SUPPORT Human Clinical
"Clinical examination demonstrates tenderness over the calcaneal insertion point of the Achilles tendon and a positive squeeze test involving manual medial and lateral compression of the posterior calcaneus."
Describes the pathognomonic clinical examination findings for Sever disease.
Second Metatarsal Head Forefoot Pain HP:0025238 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Forefoot pain over the second metatarsal head, annotated with Foot pain (HP:0025238). HP:0025238 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:30685014 SUPPORT Human Clinical
"Freiberg disease is characterized as osteochondrosis of the second metatarsal head."
Establishes the anatomic site of pain and pathology for Freiberg infraction.
Osteochondritis Dissecans Lesion HP:0010886 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Osteochondritis dissecans (HP:0010886). HP:0010886 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:34109940 SUPPORT Human Clinical
"Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis."
Establishes anatomic sites and the premature-osteoarthritis consequence of unresolved osteochondritis dissecans lesions.
Fragmented and Flattened Epiphysis Fragmented, irregular epiphyses HP:0005063 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Fragmented, irregular epiphysis, annotated with Fragmented, irregular epiphyses (HP:0005063). HP:0005063 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23254328 SUPPORT Human Clinical
"Osteochondrosis is a heterogeneous group of self-limiting conditions characterized by disturbance of enchondral ossification caused by a lack of circulation."
Reiterates the shared circulation/ossification-disturbance basis for the radiographic fragmentation phenotype across sites within the articular family.
🧬

Genetic Associations

4
COL2A1 (A rare autosomal dominant Mendelian type II collagenopathy phenocopy of Legg-Calve-Perthes disease. Most LCPD cases are sporadic and non-Mendelian, but familial/bilateral cases should raise suspicion for a COL2A1 mutation. )
Gene: COL2A1 hgnc:2200 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is COL2A1 (hgnc:2200). hgnc:2200 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: CAUSATIVE variant_origin: GERMLINE
Show evidence (1 reference)
PMID:17394019 SUPPORT Human Clinical
"We have located a missense mutation (p.G1170S) in the type II collagen gene (COL2A1) in a Japanese family with an autosomal dominant hip disorder manifesting as LCPD"
Identifies a specific COL2A1 missense mutation causing an autosomal dominant LCPD phenocopy in a familial case.
F5 (Factor V Leiden) (The Factor V Leiden thrombophilic variant is associated with increased risk of Legg-Calve-Perthes disease, supporting a thrombotic/coagulation contribution to the ischemic mechanism in at least a subset of cases. )
Gene: F5 hgnc:3542 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is F5 (hgnc:3542). hgnc:3542 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: RISK_FACTOR
Show evidence (1 reference)
PMID:20048104 SUPPORT Human Clinical
"The incidence of Legg-Calvé-Perthes disease was increased in the presence of the factor V Leiden mutation (odds ratio, 3.3; 95% confidence interval, 1.6 to 6.7)"
Case-control study reporting the odds ratio for Legg-Calve-Perthes disease associated with the Factor V Leiden mutation.
F2 (Prothrombin G20210A) (The prothrombin G20210A variant is likewise associated with increased risk of Legg-Calve-Perthes disease in the same cohort as the Factor V Leiden finding. )
Gene: F2 hgnc:3535 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is F2 (hgnc:3535). hgnc:3535 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: RISK_FACTOR
Show evidence (1 reference)
PMID:20048104 SUPPORT Human Clinical
"in the presence of the prothrombin G20210A mutation (odds ratio, 2.6; 95% confidence interval, 1.0 to 6.3)"
Case-control study reporting the odds ratio for Legg-Calve-Perthes disease associated with the prothrombin G20210A mutation.
ACAN (A rare autosomal dominant monogenic subtype of osteochondritis dissecans (familial OCD, OMIM 165800), distinct from the common sporadic/multifactorial form. Missense variants cluster in the C-type lectin repeat of the C-terminal G3 globular domain of the aggrecan proteoglycan, impairing secretion and matrix-ligand binding, and typically co-occur with short stature and early-onset osteoarthritis. )
Gene: ACAN hgnc:319 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is ACAN (hgnc:319). hgnc:319 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: CAUSATIVE variant_origin: GERMLINE
Show evidence (2 references)
PMID:35338222 SUPPORT Human Clinical
"these are autosomal dominant missense variants, resulting in single amino acid residue substitutions in the C-type lectin repeat of the aggrecan G3 domain"
Identifies the shared molecular lesion (autosomal dominant ACAN missense variants in the aggrecan G3 domain C-type lectin repeat) across families with familial osteochondritis dissecans.
PMID:35338222 SUPPORT In Vitro
"this supports a link between missense ACAN variants affecting the aggrecan G3 domain and hereditary osteochondritis dissecans"
Functional secretion and ligand-binding assays on recombinant variant aggrecan protein support the causal link between G3-domain ACAN missense variants and hereditary osteochondritis dissecans.
💊

Medical Actions

4
Activity Modification and Relative Rest
Action: supportive careNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is supportive care (NCIT:C15747). NCIT:C15747 is a clinical intervention from the NCI Thesaurus. Ontology label: Supportive Care NCIT:C15747
First-line conservative management across nearly all osteochondrosis subtypes: reduction of the offending sport/activity load, with symptom resolution typically following once loading is reduced or the growth plate/apophysis fuses.
Target Phenotypes: Knee pain HP:0030839 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Knee pain (HP:0030839). HP:0030839 is a phenotype from the Human Phenotype Ontology. Foot pain HP:0025238 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Foot pain (HP:0025238). HP:0025238 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:28722957 SUPPORT Human Clinical
"Sever disease typically follows a self-limited course, and its management involves activity modification or relative rest in response to pain."
Establishes activity modification/relative rest as first-line management for the apophyseal osteochondrosis family.
PMID:35740763 SUPPORT Human Clinical
"The treatment is usually conservative, but some surgical options can be considered when conservative treatment fails or in some limited cases."
Confirms conservative management as first-line, with surgery reserved for refractory cases.
Femoral Head Containment (Bracing or Osteotomy)
Action: orthopedic surgical procedureNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is orthopedic surgical procedure (NCIT:C16186). NCIT:C16186 is a clinical intervention from the NCI Thesaurus. Ontology label: Orthopedic Surgical Procedure NCIT:C16186
In Legg-Calve-Perthes disease, biomechanical containment of the femoral head within the acetabulum (via bracing or surgical osteotomy) aims to preserve a spherical joint surface while revascularization and remodeling occur, though multicenter studies report only modest success in older children.
Mechanism Target:
MODULATES Revascularization and Remodeling under Mechanical Load — Containment surgery is intended to redistribute mechanical load on the healing femoral head so that remodeling produces a spherical joint surface rather than progressive deformity.
Target Phenotypes: Hip pain HP:0030838 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Hip pain (HP:0030838). HP:0030838 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:22488623 SUPPORT Human Clinical
"current nonoperative and operative treatments have modest success rates of producing a good outcome with a spherical femoral head in older children with Legg-Calvé-Perthes disease"
Reports only modest success for current containment strategies in older children, so support is treated as partial rather than full.
Surgical Excision, Fixation, or Retroarticular Drilling
Action: surgical procedureNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is surgical procedure (NCIT:C15329). NCIT:C15329 is a clinical intervention from the NCI Thesaurus. Ontology label: Surgical Procedure NCIT:C15329
Unstable osteochondritis dissecans lesions (with articular cartilage fracture or subchondral bone separation) that fail conservative management in skeletally immature patients are managed operatively; treatment choice depends on skeletal maturity and lesion stability.
Mechanism Target:
MODULATES Delayed Endochondral Ossification and Necrotic Fragmentation — Surgical fixation or drilling of an unstable osteochondritis dissecans lesion is intended to promote healing of the fragmented subchondral bone/cartilage rather than progression to a loose body.
Show evidence (2 references)
PMID:34109940 SUPPORT Human Clinical
"Treatment largely depends on skeletal maturity and lesion stability, defined by the presence or absence of articular cartilage fracture and subchondral bone separation, as determined by imaging and arthroscopy, and is typically nonoperative for stable lesions in skeletally immature patients and..."
Establishes the maturity/stability-dependent decision between nonoperative and operative management of osteochondritis dissecans.
PMID:37039536 SUPPORT Human Clinical
"Healing parameters were superior at 6 months and 12 months in the TAD group, compared with the RAD group"
Prospective multicenter randomized controlled trial (ROCK Group, Level of evidence 1, n=91) directly comparing the two drilling techniques named in this treatment and reporting superior early healing with transarticular over retroarticular drilling.
Thoracolumbosacral Orthosis Bracing
Action: therapeutic procedureNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is therapeutic procedure (NCIT:C49236). NCIT:C49236 is a clinical intervention from the NCI Thesaurus. Ontology label: Therapeutic Procedure NCIT:C49236
Bracing (TLSO) is used for skeletally immature patients with symptomatic or progressive Scheuermann kyphosis to limit curve progression during remaining growth; surgery is reserved for large, progressive, symptomatic deformity.
Target Phenotypes: Kyphosis HP:0002808 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Kyphosis (HP:0002808). HP:0002808 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:37615931 SUPPORT Human Clinical
"Nonoperative treatment consists of physical therapy in symptomatic patients, and bracing can be added for skeletally mature patients. Operative management can be considered in patients with large, progressive, and symptomatic deformity."
Describes the stepwise nonoperative-to-operative management pathway for Scheuermann kyphosis.
🌍

Environmental Factors

3
Secondhand Tobacco Smoke Exposure
Household secondhand smoke exposure is a significant, dose-associated risk factor for Legg-Calve-Perthes disease in a prospective case-control study; proposed to represent an "unknown industrial factor" acting on the same ischemic mechanism as the articular family (e.g., via vasoconstriction or impaired microcirculation), though a firm mechanistic link is not established. No ECTO term for secondhand/environmental tobacco smoke exposure was found in the local cache or via a targeted OAK search at curation time.
Show evidence (1 reference)
PMID:15599226 SUPPORT Human Clinical
"A significant association was noted between living with a smoker and Legg-Calvé-Perthes disease as well as between increasing smoke exposure and increased risk of developing Legg-Calvé-Perthes disease."
Establishes that household second-hand smoke exposure is itself a documented exposure in this disease, with a dose-response relationship. This attests the exposure entry; the separate evidence on the influences_mechanisms link attests the claim that it acts on the ischemic chondronecrosis node.
Mechanism Target:
PREDISPOSES Cartilage-Canal Ischemic Chondronecrosis — Second-hand smoke exposure is proposed to predispose to the ischemic chondronecrosis underlying Legg-Calve-Perthes disease, though the intermediate vascular mechanism has not been established.
Show evidence (1 reference)
PMID:15599226 SUPPORT Human Clinical
"The presence of second-hand smoke seems to be a significant risk factor in the development of Legg-Calvé-Perthes disease."
Prospective case-control study reporting a significant association between household secondhand smoke exposure and Legg-Calve-Perthes disease.
Childhood Obesity
Extreme childhood obesity is reported as a risk factor for osteochondritis dissecans across multiple joints (knee, ankle, elbow), independent of the repetitive-loading exposure above.
Show evidence (1 reference)
PMID:38671714 SUPPORT Human Clinical
"There is an established link between childhood obesity and the occurrence of OCD in the knees, ankles, and elbows of children."
Establishes childhood obesity as a documented exposure associated with osteochondritis dissecans across multiple joints.
Mechanism Target:
PREDISPOSES Cartilage-Canal Ischemic Chondronecrosis — Extreme obesity is reported to substantially increase the risk of osteochondritis dissecans, plausibly via increased mechanical loading of cartilage-canal-dependent epiphyseal sites, though the intermediate mechanism has not been established.
Show evidence (1 reference)
PMID:38671714 SUPPORT Human Clinical
"Research by Kessler et al. indicates that extremely obese patients face an 86% increased risk of developing any type of OCD compared to individuals of normal weight"
Quantifies the increased risk of osteochondritis dissecans associated with extreme obesity.
🔬

Diagnosis

2
Plain Radiography
Plain radiographs are first-line for detecting the characteristic sclerosis, flattening, fragmentation, wedging, or irregularity at the affected epiphysis or apophysis across the osteochondrosis family, and are usually sufficient for a clinical diagnosis of the apophyseal subtypes (Osgood-Schlatter disease, Sever disease).
X-ray imaging NCIT:C38101 NCI Thesaurus (NCIT)
Show evidence (1 reference)
PMID:28722957 SUPPORT Human Clinical
"The diagnosis of Sever disease is primarily clinical and does not necessitate imaging studies. However, plain radiographs can assist in ruling out bone fractures"
Confirms that the apophyseal subtypes are diagnosed clinically, with radiography reserved to exclude alternative diagnoses.
Magnetic Resonance Imaging
MRI is used when radiographs are normal or equivocal, particularly early in the articular family (before radiographic sclerosis/fragmentation is visible) and to stage osteochondritis dissecans lesions by cartilage and subchondral bone integrity.
magnetic resonance imaging NCIT:C16809 NCI Thesaurus (NCIT)
Show evidence (1 reference)
PMID:34109940 SUPPORT Human Clinical
"Diagnosis is based on the history, physical examination, radiography, and advanced imaging, with elbow ultrasonography and novel magnetic resonance imaging protocols potentially enabling early detection and in-depth staging."
Establishes advanced MRI protocols as tools for early detection and lesion staging in osteochondritis dissecans.
📊

Prevalence

5
Children under 15 years of age
Point Prevalence 0.4–29.0 per 100,000 1–9 per 100,000 Legg-Calve-Perthes Disease
Reported estimates from a 2019 systematic review of 64 articles ranged widely (0.4 to 29.0 per 100,000), depending on the population studied; the coarse band above reflects the middle of that reported range rather than a single consensus estimate.
Show evidence (1 reference)
PMID:30918798 SUPPORT Human Clinical
"Its prevalence is set to be between 0.4/100000 to 29.0/100000 children less than 15 years of age with a peak of incidence in children aged from 4 years to 8 years."
Systematic review reporting the population prevalence range for Legg-Calve-Perthes disease.
Sport-practicing children and adolescents
Point Prevalence 9800.0 per 100,000 >1 in 1,000 Osgood-Schlatter Disease
Show evidence (1 reference)
PMID:35740763 SUPPORT Human Clinical
"The prevalence of OD is 9.8%, and it can be bilateral in 20–30% of patients"
Systematic review reporting population prevalence for Osgood-Schlatter disease.
Overall (Danish Twin Registry)
Point Prevalence 2800.0 per 100,000 >1 in 1,000 Scheuermann Kyphosis
Show evidence (1 reference)
PMID:17015588 SUPPORT Human Clinical
"the overall prevalence of Scheuermann disease was 2.8%, with a prevalence of 2.1% among women and 3.6% among men"
Danish Twin Registry study establishing overall population prevalence of Scheuermann kyphosis.
Women (Danish Twin Registry)
Point Prevalence 2100.0 per 100,000 >1 in 1,000 Scheuermann Kyphosis
Show evidence (1 reference)
PMID:17015588 SUPPORT Human Clinical
"the overall prevalence of Scheuermann disease was 2.8%, with a prevalence of 2.1% among women and 3.6% among men"
Reports the sex-stratified prevalence among women.
Men (Danish Twin Registry)
Point Prevalence 3600.0 per 100,000 >1 in 1,000 Scheuermann Kyphosis
Show evidence (1 reference)
PMID:17015588 SUPPORT Human Clinical
"the overall prevalence of Scheuermann disease was 2.8%, with a prevalence of 2.1% among women and 3.6% among men"
Reports the sex-stratified prevalence among men.
🔬

Clinical Trials

1
NCT01754298 NOT_APPLICABLE COMPLETED
Prospective multicenter randomized controlled trial (the ROCK Group, 14 centers, 17 surgeon-investigators) comparing transarticular drilling (TAD) against retroarticular drilling (RAD) for stable osteochondritis dissecans lesions of the medial femoral condyle in skeletally immature patients who had failed at least 3 months of nonoperative treatment.
Target Phenotypes: Osteochondritis dissecans HP:0010886 Human Phenotype Ontology (HP) Relation: this clinical trial targets this phenotype This clinical trial targets Osteochondritis dissecans (HP:0010886). HP:0010886 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:37039536 SUPPORT Human Clinical
"Randomized controlled clinical trial; Level of evidence, 1."
States the trial design and evidence level for this head-to-head comparison of the two drilling techniques modeled in the "Surgical Excision, Fixation, or Retroarticular Drilling" treatment.
PMID:37039536 SUPPORT Human Clinical
"A total of 91 patients were included, consisting of 51 patients in the TAD and 40 patients in the RAD group, who were similar in age, sex distribution, and 2-year PRO response rate."
Reports the trial's enrolled population size and randomization arms.
{ }

Source YAML

click to show 
name: Osteochondrosis
creation_date: "2026-08-26T00:00:00Z"
category: Complex
description: >
  Osteochondrosis is a group of disorders of growing bone in which disturbance
  of endochondral ossification at an epiphysis or apophysis leads to necrosis,
  fragmentation, and subsequent repair/remodeling. MONDO places the term as a
  child of osteonecrosis (osteochondrosis "not specified as adult or juvenile,
  of unspecified site"), but the classical (Siffert) nosology in fact splits
  the family into three mechanistically distinct groups, which this entry
  models as three separate pathophysiology chains rather than one lumped
  cascade: (1) an articular/epiphyseal group in which cartilage-canal vessel
  failure causes true ischemic chondronecrosis (Legg-Calve-Perthes disease,
  Kohler disease, Freiberg infraction, and osteochondritis dissecans); (2) a
  non-articular apophyseal group driven by repetitive tensile traction at a
  tendon insertion, not primary ischemia (Osgood-Schlatter disease, Sever
  disease); and (3) a physeal/endplate group driven by compressive
  growth-cartilage failure at the vertebral ring apophysis (Scheuermann
  kyphosis). Only the first group is truly ischemic/necrotic; the apophyseal
  and physeal groups are grouped with osteochondrosis by clinical convention
  (shared growing-bone, self-limited-then-remodeling phenotype) rather than by
  a shared vascular mechanism. Kohler disease is already curated as its own
  dismech entry (kb/disorders/Osteochondritis_of_Tarsal_Metatarsal_Bone.yaml,
  MONDO:0016086) and is cross-referenced here by name rather than duplicated.
disease_term:
  preferred_term: osteochondrosis
  term:
    id: MONDO:0018381
    label: osteochondrosis
parents:
- Osteonecrosis
- Bone disease
synonyms:
- Osteochondrosis not specified as adult or juvenile, of unspecified site
- Juvenile osteochondrosis
- Osteochondroses
has_subtypes:
- name: Legg-Calve-Perthes Disease
  display_name: Legg-Calve-Perthes Disease (Femoral Head)
  subtype_term:
    preferred_term: Legg-Calve-Perthes disease
    term:
      id: MONDO:0007885
      label: Legg-Calve-Perthes disease
  description: >
    Idiopathic juvenile osteonecrosis of the femoral head, the prototypical and
    most-studied member of the articular/epiphyseal osteochondrosis family.
    Reported prevalence ranges from 0.4 to 29.0 per 100,000 children under 15
    years of age, with a peak incidence between 4 and 8 years and a male
    predominance. Etiology remains debated: mechanically induced ischemia of
    the capital femoral epiphysis is the best-supported theory, with additional
    evidence for a thrombotic/coagulation component and, rarely, a Mendelian
    type II collagenopathy phenocopy (COL2A1).
  inheritance:
  - name: Autosomal dominant COL2A1 phenocopy
    inheritance_term:
      preferred_term: Autosomal dominant inheritance
      term:
        id: HP:0000006
        label: Autosomal dominant inheritance
    description: >-
      The rare COL2A1-associated type II collagenopathy phenocopy of LCPD is
      autosomal dominant; the common sporadic form of Legg-Calve-Perthes
      disease is not Mendelian and is considered multifactorial (mechanical,
      thrombotic/coagulation, and environmental contributors), per the
      etiology KNOWLEDGE_GAP discussion below.
    evidence:
    - reference: PMID:17394019
      reference_title: "A recurrent mutation in type II collagen gene causes Legg-Calvé-Perthes disease in a Japanese family."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "a Japanese family with an autosomal dominant hip disorder manifesting as LCPD"
      explanation: >-
        Directly states the autosomal dominant inheritance pattern of the
        COL2A1-linked LCPD phenocopy family.
  evidence:
  - reference: PMID:30918798
    reference_title: "Aetiology of Legg-Calvé-Perthes disease: A systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Its prevalence is set to be between 0.4/100000 to 29.0/100000 children less than 15 years of age with a peak of incidence in children aged from 4 years to 8 years."
    explanation: >
      Systematic review reporting the population prevalence range and peak
      age of onset for Legg-Calve-Perthes disease.
- name: Osgood-Schlatter Disease
  display_name: Osgood-Schlatter Disease (Tibial Tuberosity)
  subtype_term:
    preferred_term: Osgood-Schlatter disease
    term:
      id: MONDO:0004241
      label: Osgood-Schlatter disease
  description: >
    Traction apophysitis of the tibial tuberosity, the prototypical member of
    the non-articular apophyseal osteochondrosis family. It is the most common
    knee osteochondrosis in sport-practicing children and adolescents, with
    reported prevalence around 9.8% and bilateral involvement in 20-30% of
    affected individuals. Onset coincides with appearance of the tibial
    tuberosity secondary ossification center and is linked to sports with an
    explosive/jumping component; the mechanism is repetitive tensile traction
    at the patellar tendon insertion rather than primary ischemia.
  evidence:
  - reference: PMID:35740763
    reference_title: "The Etiology and Risk Factors of Osgood-Schlatter Disease: A Systematic Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The prevalence of OD is 9.8%, and it can be bilateral in 20–30% of patients"
    explanation: >
      Systematic review reporting population prevalence and rate of bilateral
      involvement for Osgood-Schlatter disease.
- name: Sever Disease
  display_name: Sever Disease (Calcaneal Apophysis)
  subtype_term:
    preferred_term: Sever disease (calcaneal apophysitis)
  description: >
    Traction apophysitis of the calcaneal apophysis at the Achilles tendon
    insertion, the second member of the non-articular apophyseal family. No
    MONDO term currently exists for this concept (OLS/Ontobee search returns
    no MONDO hit), so this subtype is modeled with a free-text
    `subtype_term.preferred_term` only. It is a common cause of heel pain in
    children and young athletes aged 8 to 15 with immature skeletons, arising
    from repetitive microtrauma to the secondary ossification center by
    traction of the Achilles tendon insertion, often compounded by
    triceps-surae tightness from a growth-rate mismatch between bone and
    muscle-tendon length.
  evidence:
  - reference: PMID:28722957
    reference_title: "Sever Disease (Calcaneal Apophysitis)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Sever disease results from repetitive microtrauma to the secondary ossification center by traction of the Achilles tendon insertion on the calcaneus."
    explanation: >
      Establishes the traction-apophysitis mechanism and anatomic site for
      Sever disease.
- name: Kohler Disease
  display_name: Kohler Disease (Navicular)
  subtype_term:
    preferred_term: osteochondritis of tarsal/metatarsal bone
    term:
      id: MONDO:0016086
      label: osteochondritis of tarsal/metatarsal bone
  description: >
    Ischemic osteochondrosis of the tarsal navicular, a member of the
    articular/epiphyseal family. Curated as its own dismech entry — see
    kb/disorders/Osteochondritis_of_Tarsal_Metatarsal_Bone.yaml for full
    phenotype, evidence, and treatment content (which also disambiguates it
    from adult Muller-Weiss disease and from Freiberg disease). Included here
    only for completeness of the site-based osteochondrosis subtype list; not
    duplicated.
  review_notes: >
    No new evidence added on this subtype; content lives entirely in the
    linked standalone entry to avoid duplication.
- name: Freiberg Infraction
  display_name: Freiberg Infraction (Second Metatarsal Head)
  subtype_term:
    preferred_term: Freiberg infraction
    term:
      id: MONDO:0023188
      label: Freiberg disease
  description: >
    Ischemic osteochondrosis of the second metatarsal head, a member of the
    articular/epiphyseal family. It is the fourth most common form of primary
    osteochondrosis, with a strong predilection for adolescent athletic
    females, though it has been reported across a wide age range. Like other
    members of the articular family it is generally self-limited when treated
    early, resolving with nonoperative management.
  evidence:
  - reference: PMID:30685014
    reference_title: "Freiberg Disease and Avascular Necrosis of the Metatarsal Heads."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Freiberg disease is characterized as osteochondrosis of the second metatarsal head. It is the fourth most common form of primary osteochondrosis with a significant predilection to the adolescent athletic female population"
    explanation: >
      Defines the anatomic site and relative frequency/demographic
      predilection of Freiberg disease among the primary osteochondroses.
- name: Scheuermann Kyphosis
  display_name: Scheuermann Kyphosis (Vertebral Ring Apophyses)
  subtype_term:
    preferred_term: Scheuermann kyphosis
    term:
      id: MONDO:0008410
      label: Scheuermann disease
  description: >
    Structural thoracic kyphosis of the physeal/endplate osteochondrosis
    family, diagnosed radiographically by Sorensen's criteria (at least three
    consecutive vertebrae wedged by five degrees or more at the apex of the
    deformity). Population prevalence is approximately 2.8% (2.1% in women,
    3.6% in men), and a Danish twin-registry study estimated heritability at
    74%, indicating a major genetic contribution distinct from the primarily
    biomechanical apophyseal family. Unlike Legg-Calve-Perthes disease,
    Osgood-Schlatter disease, and Sever disease, this subtype is not driven by
    vascular ischemia or tendon traction but by compressive failure of the
    cartilaginous vertebral endplate and ring apophysis.
  evidence:
  - reference: PMID:17015588
    reference_title: "Prevalence, concordance, and heritability of Scheuermann kyphosis based on a study of twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the overall prevalence of Scheuermann disease was 2.8%, with a prevalence of 2.1% among women and 3.6% among men"
    explanation: >
      Danish Twin Registry study establishing population prevalence and sex
      distribution of Scheuermann kyphosis.
  - reference: PMID:17015588
    reference_title: "Prevalence, concordance, and heritability of Scheuermann kyphosis based on a study of twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "These differences were significant (p < 0.01). Heritability was 74%."
    explanation: >
      Reports the heritability estimate that distinguishes Scheuermann
      kyphosis from the mechanically-dominant apophyseal osteochondroses.
- name: Osteochondritis Dissecans
  display_name: Osteochondritis Dissecans (Articular Surface)
  subtype_term:
    preferred_term: osteochondritis dissecans
    term:
      id: MONDO:0017178
      label: osteochondritis dissecans
  description: >
    Acquired focal lesion of subchondral bone and overlying articular
    cartilage, most commonly of the knee, elbow, or ankle, that can progress
    to a detached osteochondral fragment (loose body) and secondary
    osteoarthritis. Experimental (foal) and human cadaveric/CT-histology
    studies support the same ischemic-chondronecrosis mechanism as the rest of
    the articular osteochondrosis family: failure of epiphyseal cartilage-canal
    blood supply causes focal chondronecrosis and a delay in endochondral
    ossification (osteochondrosis), which can subsequently progress to
    pathological cartilage fracture (osteochondritis dissecans).
  inheritance:
  - name: Autosomal dominant ACAN familial OCD
    inheritance_term:
      preferred_term: Autosomal dominant inheritance
      term:
        id: HP:0000006
        label: Autosomal dominant inheritance
    description: >-
      The rare ACAN-associated familial osteochondritis dissecans subtype
      (OMIM 165800) is autosomal dominant; common sporadic OCD is
      multifactorial (ischemic, mechanical, and polygenic contributors) and
      is not Mendelian.
    evidence:
    - reference: PMID:35338222
      reference_title: "Novel missense ACAN gene variants linked to familial osteochondritis dissecans cluster in the C-terminal globular domain of aggrecan."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "these are autosomal dominant missense variants, resulting in single amino acid residue substitutions in the C-type lectin repeat of the aggrecan G3 domain"
      explanation: >-
        Directly states the autosomal dominant inheritance pattern of the
        ACAN-linked familial OCD variants.
  review_notes: >
    Deliberate divergence from current MONDO structure, recorded per the
    curation-brief guidance on issue #8963: in MONDO, osteochondritis
    dissecans (MONDO:0017178) is classified under MONDO:0018383 "osteonecrosis
    of genetic origin" rather than as a direct child of MONDO:0018381
    "osteochondrosis". This entry follows the modern experimental/translational
    literature (PMID:23428601, PMID:30248503), which places OCD/JOCD squarely
    in the ischemic-cartilage-canal osteochondrosis family alongside Perthes,
    Kohler, and Freiberg disease, and models it here as a site-general
    has_subtypes member rather than following MONDO's genetic-osteonecrosis
    placement. A MONDO ticket to reconsider this placement may be warranted but
    is out of scope for this entry.
  evidence:
  - reference: PMID:34109940
    reference_title: "Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis."
    explanation: >
      Establishes the demographic pattern, anatomic sites, and long-term
      consequence (premature osteoarthritis) of osteochondritis dissecans.
  - reference: PMID:34109940
    reference_title: "Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "various etiopathogenetic theories are being investigated, including local ischemia, aberrant endochondral ossification of the secondary subarticular physis, repetitive microtrauma, and genetic predisposition"
    explanation: >
      Confirms local ischemia and aberrant endochondral ossification as
      leading etiopathogenetic theories for osteochondritis dissecans,
      consistent with the articular osteochondrosis mechanism.
prevalence:
- subtype: Legg-Calve-Perthes Disease
  population: Children under 15 years of age
  measure_type: POINT_PREVALENCE
  prevalence_class: BAND_1_9_PER_100000
  rate_low: 0.4
  rate_high: 29.0
  notes: >-
    Reported estimates from a 2019 systematic review of 64 articles ranged
    widely (0.4 to 29.0 per 100,000), depending on the population studied;
    the coarse band above reflects the middle of that reported range rather
    than a single consensus estimate.
  evidence:
  - reference: PMID:30918798
    reference_title: "Aetiology of Legg-Calvé-Perthes disease: A systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Its prevalence is set to be between 0.4/100000 to 29.0/100000 children less than 15 years of age with a peak of incidence in children aged from 4 years to 8 years."
    explanation: >-
      Systematic review reporting the population prevalence range for
      Legg-Calve-Perthes disease.
- subtype: Osgood-Schlatter Disease
  population: Sport-practicing children and adolescents
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 9800.0
  evidence:
  - reference: PMID:35740763
    reference_title: "The Etiology and Risk Factors of Osgood-Schlatter Disease: A Systematic Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The prevalence of OD is 9.8%, and it can be bilateral in 20–30% of patients"
    explanation: >-
      Systematic review reporting population prevalence for Osgood-Schlatter
      disease.
- subtype: Scheuermann Kyphosis
  population: Overall (Danish Twin Registry)
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 2800.0
  evidence:
  - reference: PMID:17015588
    reference_title: "Prevalence, concordance, and heritability of Scheuermann kyphosis based on a study of twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the overall prevalence of Scheuermann disease was 2.8%, with a prevalence of 2.1% among women and 3.6% among men"
    explanation: >-
      Danish Twin Registry study establishing overall population prevalence
      of Scheuermann kyphosis.
- subtype: Scheuermann Kyphosis
  population: Women (Danish Twin Registry)
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 2100.0
  evidence:
  - reference: PMID:17015588
    reference_title: "Prevalence, concordance, and heritability of Scheuermann kyphosis based on a study of twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the overall prevalence of Scheuermann disease was 2.8%, with a prevalence of 2.1% among women and 3.6% among men"
    explanation: >-
      Reports the sex-stratified prevalence among women.
- subtype: Scheuermann Kyphosis
  population: Men (Danish Twin Registry)
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 3600.0
  evidence:
  - reference: PMID:17015588
    reference_title: "Prevalence, concordance, and heritability of Scheuermann kyphosis based on a study of twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the overall prevalence of Scheuermann disease was 2.8%, with a prevalence of 2.1% among women and 3.6% among men"
    explanation: >-
      Reports the sex-stratified prevalence among men.
pathophysiology:
- name: Cartilage-Canal Ischemic Chondronecrosis
  biological_scale: CELLULAR
  subtypes:
  - Legg-Calve-Perthes Disease
  - Kohler Disease
  - Freiberg Infraction
  - Osteochondritis Dissecans
  description: >
    In the articular/epiphyseal osteochondrosis family, blood vessels running
    through cartilage canals supply the secondary (epiphyseal) ossification
    center during growth. Focal failure or transection of these vessels causes
    ischemic necrosis of chondrocytes and vascular endothelium in the
    epiphyseal cartilage, before any bone is yet mineralized at that site. This
    mechanism was reproduced experimentally by surgically transecting
    cartilage-canal vessels in foals, and morphologically identical lesions
    (confirmed by histology to represent cartilage-canal blood-supply failure
    and ischemic chondronecrosis) were subsequently identified at the
    predilection sites for juvenile osteochondritis dissecans in human
    pediatric knee specimens.
  cell_types:
  - preferred_term: Chondrocyte
    term:
      id: CL:0000138
      label: chondrocyte
  - preferred_term: Growth plate cartilage chondrocyte
    term:
      id: CL:1000217
      label: growth plate cartilage chondrocyte
  biological_processes:
  - preferred_term: Response to hypoxia (cartilage-canal ischemia)
    term:
      id: GO:0001666
      label: response to hypoxia
  - preferred_term: Chondrocyte and vascular endothelial cell death
    modifier: INCREASED
    term:
      id: GO:0008219
      label: cell death
  locations:
  - preferred_term: Epiphyseal cartilage canal
    term:
      id: UBERON:0001437
      label: epiphysis
  - preferred_term: Subchondral region of epiphysis
    term:
      id: UBERON:0035878
      label: subchondral region of epiphysis
  evidence:
  - reference: PMID:23428601
    reference_title: "Transection of vessels in epiphyseal cartilage canals leads to osteochondrosis and osteochondrosis dissecans in the femoro-patellar joint of foals; a potential model of juvenile osteochondritis dissecans."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Transection of blood vessels within epiphyseal cartilage canals resulted in necrosis of vessels and chondrocytes, i.e., ischaemic chondronecrosis, in foals."
    explanation: >
      Causal experimental evidence (surgical vessel transection) directly
      demonstrating that cartilage-canal vascular failure produces ischemic
      chondronecrosis, the initiating lesion of the articular osteochondrosis
      family.
  - reference: PMID:30248503
    reference_title: "Juvenile osteochondritis dissecans of the knee is a result of failure of the blood supply to growth cartilage and osteochondrosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Changes identical to osteochondrosis in animals were detected at predilection sites for JOCD in children, and confirmed to represent failure of the cartilage canal blood supply and ischemic chondronecrosis in histological sections."
    explanation: >
      Human pediatric CT/histology study translating the animal-model
      ischemic-chondronecrosis mechanism to human juvenile osteochondritis
      dissecans predilection sites.
  downstream:
  - target: Delayed Endochondral Ossification and Necrotic Fragmentation
    description: >
      Ischemic chondronecrosis produces a focal delay in endochondral
      ossification at the affected site; if loading continues before
      ossification and repair catch up, the necrotic/weakened cartilage-bone
      interface is prone to structural collapse and fragmentation.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:23428601
      reference_title: "Transection of vessels in epiphyseal cartilage canals leads to osteochondrosis and osteochondrosis dissecans in the femoro-patellar joint of foals; a potential model of juvenile osteochondritis dissecans."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Areas of ischaemic chondronecrosis were associated with a focal delay in enchondral ossification (OC) in foals examined 21 days or more after transection, and pathological cartilage fracture (OCD) in one foal examined 42 days after transection."
      explanation: >
        Direct causal-experiment evidence for the temporal sequence
        ischemic chondronecrosis -> delayed ossification (osteochondrosis) ->
        cartilage fracture (osteochondritis dissecans).
- name: Delayed Endochondral Ossification and Necrotic Fragmentation
  biological_scale: TISSUE
  subtypes:
  - Legg-Calve-Perthes Disease
  - Kohler Disease
  - Freiberg Infraction
  - Osteochondritis Dissecans
  description: >
    The necrotic, unossified cartilage/subchondral bone segment fails to bear
    load normally. Continued mechanical loading of the affected epiphysis or
    subarticular bone (e.g., the immature femoral head in Perthes disease, or
    the second metatarsal head in Freiberg infraction) leads to increased bone
    resorption relative to delayed new bone formation, producing structural
    weakening, collapse, sclerosis, flattening, and fragmentation on imaging.
    In the most severe articular presentations this culminates in pathological
    cartilage fracture and, in osteochondritis dissecans, a detached
    osteochondral fragment (loose body).
  biological_processes:
  - preferred_term: Delayed endochondral ossification
    modifier: DECREASED
    term:
      id: GO:0001958
      label: endochondral ossification
  - preferred_term: Bone resorption
    modifier: INCREASED
    term:
      id: GO:0045453
      label: bone resorption
  evidence:
  - reference: PMID:22488623
    reference_title: "Pathophysiology and new strategies for the treatment of Legg-Calvé-Perthes disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the immature femoral head is mechanically weakened following ischemic necrosis. Increased bone resorption and delayed new bone formation, in combination with continued mechanical loading of the hip, contribute to the pathogenesis of the femoral head deformity."
    explanation: >
      Establishes the resorption/formation imbalance and role of continued
      mechanical loading in producing structural deformity after ischemic
      necrosis, generalizing across the articular osteochondrosis family.
  - reference: PMID:34109940
    reference_title: "Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Treatment largely depends on skeletal maturity and lesion stability, defined by the presence or absence of articular cartilage fracture and subchondral bone separation, as determined by imaging and arthroscopy"
    explanation: >
      Confirms cartilage fracture and subchondral bone separation as the
      structural endpoints that distinguish stable from unstable
      osteochondritis dissecans lesions.
  downstream:
  - target: Revascularization and Remodeling under Mechanical Load
    description: >
      Necrotic tissue is progressively removed and replaced by vascularized
      granulation tissue and new bone (creeping substitution), which under
      continued mechanical load can restore structural integrity or, if
      loading outpaces repair, leave residual deformity.
    causal_link_type: DIRECT
- name: Revascularization and Remodeling under Mechanical Load
  biological_scale: TISSUE
  subtypes:
  - Legg-Calve-Perthes Disease
  - Kohler Disease
  - Freiberg Infraction
  description: >
    The articular osteochondrosis family is characteristically self-limited:
    revascularization delivers chondroclasts/osteoclasts and granulation
    tissue that remove necrotic tissue while new bone formation proceeds,
    under the influence of ongoing mechanical loading of the growing epiphysis.
    Outcome depends on the balance between repair and load — a spherical,
    congruent joint surface if repair keeps pace, or residual flattening/
    deformity and premature secondary osteoarthritis if mechanical failure
    outpaces repair.
  biological_processes:
  - preferred_term: Sprouting angiogenesis
    term:
      id: GO:0002040
      label: sprouting angiogenesis
  - preferred_term: Bone remodeling
    term:
      id: GO:0046849
      label: bone remodeling
  evidence:
  - reference: PMID:30248503
    reference_title: "Juvenile osteochondritis dissecans of the knee is a result of failure of the blood supply to growth cartilage and osteochondrosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Intra-cartilaginous secondary responses comprising proliferation of adjacent chondrocytes and vessels were detected in six and two lesions, whereas intra-osseous responses including accumulation of chondroclasts and formation of granulation tissue occurred in 10 and six lesions, respectively."
    explanation: >
      Human histological evidence for the revascularization/repair response
      (chondrocyte and vessel proliferation, chondroclast accumulation,
      granulation tissue formation) that follows ischemic chondronecrosis.
  - reference: PMID:30685014
    reference_title: "Freiberg Disease and Avascular Necrosis of the Metatarsal Heads."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "If treated early, osteochondroses such as Freiberg disease are essentially self-limiting, often resolving with nonoperative management."
    explanation: >
      Supports the self-limited, load-dependent repair course that
      characterizes the articular osteochondrosis family when caught early.
- name: Repetitive Traction Apophysitis
  biological_scale: TISSUE
  subtypes:
  - Osgood-Schlatter Disease
  - Sever Disease
  description: >
    In the non-articular apophyseal osteochondrosis family, the mechanism is
    NOT primary ischemia. A traction apophysis is a secondary ossification
    center at a tendon insertion (the tibial tuberosity for the patellar
    tendon in Osgood-Schlatter disease; the calcaneal apophysis for the
    Achilles tendon in Sever disease). Repetitive, forceful traction from
    running/jumping sports during a rapid growth spurt — often compounded by
    relative muscle-tendon tightness outpacing bone growth — causes chronic
    microtrauma, inflammation, and disordered ossification at the unfused
    apophysis, distinct from the ischemic mechanism of the articular family.
  biological_processes:
  - preferred_term: Response to mechanical stimulus (tendon traction)
    term:
      id: GO:0009612
      label: response to mechanical stimulus
  - preferred_term: Endochondral ossification (secondary ossification center)
    modifier: DYSREGULATED
    term:
      id: GO:0001958
      label: endochondral ossification
  locations:
  - preferred_term: Tibial tuberosity
    term:
      id: UBERON:7500062
      label: tibial tuberosity
  - preferred_term: Calcaneal apophysis
    term:
      id: UBERON:0001450
      label: calcaneus
  - preferred_term: Calcaneal (Achilles) tendon insertion
    term:
      id: UBERON:0003701
      label: calcaneal tendon
  evidence:
  - reference: PMID:35740763
    reference_title: "The Etiology and Risk Factors of Osgood-Schlatter Disease: A Systematic Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It often results from acute or chronic overload during sports activity, causing inflammation of the patellar tendon insertion on the tibial tuberosity"
    explanation: >
      Establishes the traction/overload mechanism, distinct from ischemia, at
      the tibial tuberosity apophysis in Osgood-Schlatter disease.
  - reference: PMID:28722957
    reference_title: "Sever Disease (Calcaneal Apophysitis)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The condition frequently coincides with triceps surae shortening, which stems from the difference in growth rates between bone and muscle."
    explanation: >
      Establishes the growth-rate-mismatch/tightness contributor to traction
      apophysitis at the calcaneal apophysis in Sever disease.
  downstream:
  - target: Apophyseal Pain, Prominence, and Fragmentation
    description: >
      Chronic traction produces local pain, swelling, and, radiographically,
      irregularity or fragmentation of the apophysis, without the true
      ischemic necrosis seen in the articular family.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:35742062
      reference_title: "Osgood-Schlatter Disease: Appearance, Diagnosis and Treatment: A Narrative Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Osgood-Schlatter disease is the most common osteochondritis of the lower limb in sport-practicing children and adolescents."
      explanation: >
        Confirms the clinical burden and lower-limb site of this apophyseal
        family member as manifest disease (pain/prominence), which the review
        goes on to link to sport-related mechanical loading.
- name: Apophyseal Pain, Prominence, and Fragmentation
  biological_scale: TISSUE
  subtypes:
  - Osgood-Schlatter Disease
  - Sever Disease
  description: >
    The end-stage clinical/radiographic phenotype of traction apophysitis:
    localized pain and swelling that worsen with activity and improve with
    rest, sometimes with a palpable bony prominence, and self-resolution once
    the apophysis fuses at the end of skeletal growth.
  evidence:
  - reference: PMID:28722957
    reference_title: "Sever Disease (Calcaneal Apophysitis)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients affected by Sever disease usually report pain resolution during periods of rest or when the growth plate fully closes."
    explanation: >
      Confirms the self-limited, growth-plate-fusion-dependent resolution
      pattern characteristic of the apophyseal osteochondrosis family.
- name: Compressive Vertebral Endplate Growth Failure
  biological_scale: TISSUE
  subtypes:
  - Scheuermann Kyphosis
  description: >
    In the physeal/endplate osteochondrosis family, excessive mechanical
    (compressive) loading impairs growth of the cartilaginous vertebral
    endplate and ring apophysis at the thoracic spine, distinct from both the
    ischemic mechanism of the articular family and the tensile-traction
    mechanism of the apophyseal family. This is associated with Schmorl's node
    formation (nucleus pulposus herniation through a weakened endplate),
    disruption of the ring apophysis, and compromised intervertebral disc
    integrity. A shortened sternum has also been proposed to increase
    anterior compressive force on the vertebral endplates, though this
    remains a single-study hypothesis.
  biological_processes:
  - preferred_term: Growth plate cartilage development (vertebral endplate)
    modifier: DECREASED
    term:
      id: GO:0003417
      label: growth plate cartilage development
  - preferred_term: Response to mechanical stimulus (compressive loading)
    term:
      id: GO:0009612
      label: response to mechanical stimulus
  locations:
  - preferred_term: Vertebral ring apophysis / endplate
    term:
      id: UBERON:0002347
      label: thoracic vertebra
  - preferred_term: Vertebral growth plate cartilage
    term:
      id: UBERON:0004129
      label: growth plate cartilage
  evidence:
  - reference: PMID:41594596
    reference_title: "Insights into the Pathophysiology of Scheuermann's Kyphosis: From Structural Deformities to Genetic Predisposition and Underlying Signalling Pathways."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "excessive mechanical loading as a major contributor to defective growth of the cartilaginous vertebral endplate. This is associated with the formation of Schmorl's nodes, disruption of the ring apophysis, and compromised intervertebral disc integrity"
    explanation: >
      Current review establishing compressive mechanical loading of the
      cartilaginous vertebral endplate, rather than ischemia or tendon
      traction, as the physeal-family mechanism.
  - reference: PMID:18165737
    reference_title: "The role of sternum in the etiopathogenesis of Scheuermann disease of the thoracic spine."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the smaller length of sternum than the normal has a possible correlation with the appearance of Scheuermann disease. Probably the smaller length of sternum increases the compressive forces on the vertebral endplates anteriorly, allowing uneven growth of the vertebral bodies with wedging."
    explanation: >
      Single cohort study (10,057 screened students) proposing a specific
      biomechanical contributor (short sternum) to endplate compressive
      failure; treated as partial/hypothesis-level support given the authors'
      own hedged language and the absence of independent replication.
  downstream:
  - target: Anterior Vertebral Wedging and Kyphotic Deformity
    description: >
      Uneven anterior-versus-posterior vertebral body growth under
      compression produces the characteristic wedge-shaped vertebral bodies
      and rigid thoracic hyperkyphosis diagnostic of Scheuermann kyphosis.
    causal_link_type: DIRECT
- name: Anterior Vertebral Wedging and Kyphotic Deformity
  biological_scale: TISSUE
  subtypes:
  - Scheuermann Kyphosis
  description: >
    Radiographically defined by Sorensen's criteria (at least three
    consecutive vertebrae wedged five degrees or more at the apex),
    accompanied by irregular endplates, decreased disc height, and Schmorl's
    nodes, producing a rigid dorsal kyphosis that may be accompanied by pain
    and cosmetic complaints.
  evidence:
  - reference: PMID:41594596
    reference_title: "Insights into the Pathophysiology of Scheuermann's Kyphosis: From Structural Deformities to Genetic Predisposition and Underlying Signalling Pathways."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "These require at least three consecutive vertebrae wedged by five degrees or more at the apex of the deformity, resulting in thoracic hyperkyphosis"
    explanation: >
      States the Sorensen radiographic diagnostic criteria that define the
      wedged-vertebra/kyphosis endpoint of the physeal osteochondrosis family.
phenotypes:
- category: Clinical
  name: Hip Pain and Limp
  subtypes:
  - Legg-Calve-Perthes Disease
  phenotype_term:
    preferred_term: Hip pain
    term:
      id: HP:0030838
      label: Hip pain
  description: >
    Insidious hip, groin, thigh, or knee pain (referred) with an antalgic limp
    is the classic presentation of Legg-Calve-Perthes disease.
  evidence:
  - reference: PMID:22488623
    reference_title: "Pathophysiology and new strategies for the treatment of Legg-Calvé-Perthes disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Legg-Calvé-Perthes disease is a juvenile form of idiopathic osteonecrosis of the femoral head that can lead to permanent femoral head deformity and premature osteoarthritis."
    explanation: >
      Establishes the clinical identity and femoral-head site underlying the
      hip pain/limp presentation.
- category: Radiographic
  name: Avascular Necrosis of the Capital Femoral Epiphysis
  subtypes:
  - Legg-Calve-Perthes Disease
  phenotype_term:
    preferred_term: Avascular necrosis of the capital femoral epiphysis
    term:
      id: HP:0005743
      label: Avascular necrosis of the capital femoral epiphysis
  description: >
    The femoral head epiphysis undergoes avascular necrosis with subsequent
    fragmentation, re-ossification, and healing with residual deformity.
  evidence:
  - reference: PMID:17394019
    reference_title: "A recurrent mutation in type II collagen gene causes Legg-Calvé-Perthes disease in a Japanese family."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Legg-Calvé-Perthes disease (LCPD) is a common childhood hip disorder characterized by sequential stages of involvement of the capital femoral epiphyses, including subchondral fracture, fragmentation, re-ossification and healing with residual deformity."
    explanation: >
      Describes the staged avascular-necrosis-to-healing sequence at the
      capital femoral epiphysis.
- category: Clinical
  name: Anterior Knee Pain over the Tibial Tuberosity
  subtypes:
  - Osgood-Schlatter Disease
  phenotype_term:
    preferred_term: Knee pain
    term:
      id: HP:0030839
      label: Knee pain
  description: >
    Activity-related anterior knee pain localized over the tibial tuberosity,
    often with a palpable bony prominence and local swelling, that worsens
    with running/jumping sports and improves with rest.
  evidence:
  - reference: PMID:35740763
    reference_title: "The Etiology and Risk Factors of Osgood-Schlatter Disease: A Systematic Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "insidious onset (usually atraumatic) of anterior functional knee pain over the tibial tuberosity along with a bony prominence, as well as tenderness at the patellar tendon insertion site"
    explanation: >
      Describes the characteristic clinical presentation of Osgood-Schlatter
      disease.
- category: Clinical
  name: Heel Pain
  subtypes:
  - Sever Disease
  phenotype_term:
    preferred_term: Heel pain
    term:
      id: HP:0025238
      label: Foot pain
  description: >
    Posterior heel pain at the Achilles tendon insertion, provoked by running
    and jumping sports and relieved by rest; clinical exam shows tenderness
    over the calcaneal apophysis and a positive medial-lateral squeeze test.
  evidence:
  - reference: PMID:28722957
    reference_title: "Sever Disease (Calcaneal Apophysitis)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Clinical examination demonstrates tenderness over the calcaneal insertion point of the Achilles tendon and a positive squeeze test involving manual medial and lateral compression of the posterior calcaneus."
    explanation: >
      Describes the pathognomonic clinical examination findings for Sever
      disease.
- category: Clinical
  name: Second Metatarsal Head Forefoot Pain
  subtypes:
  - Freiberg Infraction
  phenotype_term:
    preferred_term: Forefoot pain over the second metatarsal head
    term:
      id: HP:0025238
      label: Foot pain
  description: >
    Activity-related forefoot pain and swelling localized over the second
    metatarsal head, typically in adolescent athletic females.
  evidence:
  - reference: PMID:30685014
    reference_title: "Freiberg Disease and Avascular Necrosis of the Metatarsal Heads."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Freiberg disease is characterized as osteochondrosis of the second metatarsal head."
    explanation: >
      Establishes the anatomic site of pain and pathology for Freiberg
      infraction.
- category: Radiographic
  name: Thoracic Hyperkyphosis with Vertebral Wedging
  subtypes:
  - Scheuermann Kyphosis
  phenotype_term:
    preferred_term: Kyphosis
    term:
      id: HP:0002808
      label: Kyphosis
  description: >
    Rigid, structural thoracic kyphosis with anterior wedging of at least
    three consecutive vertebrae, often accompanied by mid-back pain and
    cosmetic (postural) complaints, defining Scheuermann kyphosis.
  evidence:
  - reference: PMID:41594596
    reference_title: "Insights into the Pathophysiology of Scheuermann's Kyphosis: From Structural Deformities to Genetic Predisposition and Underlying Signalling Pathways."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It presents as a rigid kyphotic deformity, often accompanied by pain and cosmetic complaints, and is diagnosed based on the radiographic criteria established by Sørensen in 1964"
    explanation: >
      Describes the clinical presentation and radiographic diagnostic basis
      of Scheuermann kyphosis.
- category: Radiographic
  name: Osteochondritis Dissecans Lesion
  subtypes:
  - Osteochondritis Dissecans
  phenotype_term:
    preferred_term: Osteochondritis dissecans
    term:
      id: HP:0010886
      label: Osteochondritis dissecans
  description: >
    A focal, sharply demarcated subchondral bone and articular cartilage
    lesion, most often at the knee, elbow, or ankle, that can progress to
    cartilage fracture and separation of an osteochondral fragment (loose
    body), with joint pain, swelling, and mechanical symptoms.
  evidence:
  - reference: PMID:34109940
    reference_title: "Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis."
    explanation: >
      Establishes anatomic sites and the premature-osteoarthritis consequence
      of unresolved osteochondritis dissecans lesions.
- category: Radiographic
  name: Fragmented and Flattened Epiphysis
  subtypes:
  - Legg-Calve-Perthes Disease
  - Freiberg Infraction
  phenotype_term:
    preferred_term: Fragmented, irregular epiphysis
    term:
      id: HP:0005063
      label: "Fragmented, irregular epiphyses"
  description: >
    Shared radiographic endpoint of the articular osteochondrosis family:
    sclerosis, flattening, and fragmentation of the affected epiphysis
    (femoral head in Perthes disease, second metatarsal head in Freiberg
    infraction) as necrotic bone is resorbed and remodeled under load.
  evidence:
  - reference: PMID:23254328
    reference_title: "[Osteochondrosis of the pediatric foot]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Osteochondrosis is a heterogeneous group of self-limiting conditions characterized by disturbance of enchondral ossification caused by a lack of circulation."
    explanation: >
      Reiterates the shared circulation/ossification-disturbance basis for
      the radiographic fragmentation phenotype across sites within the
      articular family.
- category: Clinical
  name: Premature Secondary Osteoarthritis
  subtypes:
  - Legg-Calve-Perthes Disease
  - Osteochondritis Dissecans
  phenotype_term:
    preferred_term: Premature osteoarthritis
    term:
      id: HP:0003088
      label: Premature osteoarthritis
  description: >
    The principal long-term morbidity of the articular osteochondrosis
    family: residual structural deformity of the affected epiphysis or
    articular surface predisposes to osteoarthritis at an abnormally young
    age, well before the typical age of onset for primary osteoarthritis.
  evidence:
  - reference: PMID:22488623
    reference_title: "Pathophysiology and new strategies for the treatment of Legg-Calvé-Perthes disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Legg-Calvé-Perthes disease is a juvenile form of idiopathic osteonecrosis of the femoral head that can lead to permanent femoral head deformity and premature osteoarthritis."
    explanation: >
      Identifies premature osteoarthritis as a long-term consequence of
      Legg-Calve-Perthes disease.
  - reference: PMID:34109940
    reference_title: "Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis."
    explanation: >
      Identifies premature osteoarthritis as a long-term consequence of
      unresolved osteochondritis dissecans lesions.
genetic:
- name: COL2A1
  gene_term:
    preferred_term: COL2A1
    term:
      id: hgnc:2200
      label: COL2A1
  subtype: Legg-Calve-Perthes Disease
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  presence: Rare
  association: >
    A rare autosomal dominant Mendelian type II collagenopathy phenocopy of
    Legg-Calve-Perthes disease. Most LCPD cases are sporadic and non-Mendelian,
    but familial/bilateral cases should raise suspicion for a COL2A1 mutation.
  evidence:
  - reference: PMID:17394019
    reference_title: "A recurrent mutation in type II collagen gene causes Legg-Calvé-Perthes disease in a Japanese family."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have located a missense mutation (p.G1170S) in the type II collagen gene (COL2A1) in a Japanese family with an autosomal dominant hip disorder manifesting as LCPD"
    explanation: >
      Identifies a specific COL2A1 missense mutation causing an autosomal
      dominant LCPD phenocopy in a familial case.
- name: F5 (Factor V Leiden)
  gene_term:
    preferred_term: F5
    term:
      id: hgnc:3542
      label: F5
  subtype: Legg-Calve-Perthes Disease
  relationship_type: RISK_FACTOR
  presence: Common
  association: >
    The Factor V Leiden thrombophilic variant is associated with increased
    risk of Legg-Calve-Perthes disease, supporting a thrombotic/coagulation
    contribution to the ischemic mechanism in at least a subset of cases.
  evidence:
  - reference: PMID:20048104
    reference_title: "Coagulation abnormalities in Legg-Calvé-Perthes disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The incidence of Legg-Calvé-Perthes disease was increased in the presence of the factor V Leiden mutation (odds ratio, 3.3; 95% confidence interval, 1.6 to 6.7)"
    explanation: >
      Case-control study reporting the odds ratio for Legg-Calve-Perthes
      disease associated with the Factor V Leiden mutation.
- name: F2 (Prothrombin G20210A)
  gene_term:
    preferred_term: F2
    term:
      id: hgnc:3535
      label: F2
  subtype: Legg-Calve-Perthes Disease
  relationship_type: RISK_FACTOR
  presence: Common
  association: >
    The prothrombin G20210A variant is likewise associated with increased risk
    of Legg-Calve-Perthes disease in the same cohort as the Factor V Leiden
    finding.
  evidence:
  - reference: PMID:20048104
    reference_title: "Coagulation abnormalities in Legg-Calvé-Perthes disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "in the presence of the prothrombin G20210A mutation (odds ratio, 2.6; 95% confidence interval, 1.0 to 6.3)"
    explanation: >
      Case-control study reporting the odds ratio for Legg-Calve-Perthes
      disease associated with the prothrombin G20210A mutation.
- name: ACAN
  gene_term:
    preferred_term: ACAN
    term:
      id: hgnc:319
      label: ACAN
  subtype: Osteochondritis Dissecans
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  presence: Rare
  association: >
    A rare autosomal dominant monogenic subtype of osteochondritis dissecans
    (familial OCD, OMIM 165800), distinct from the common sporadic/multifactorial
    form. Missense variants cluster in the C-type lectin repeat of the
    C-terminal G3 globular domain of the aggrecan proteoglycan, impairing
    secretion and matrix-ligand binding, and typically co-occur with short
    stature and early-onset osteoarthritis.
  evidence:
  - reference: PMID:35338222
    reference_title: "Novel missense ACAN gene variants linked to familial osteochondritis dissecans cluster in the C-terminal globular domain of aggrecan."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "these are autosomal dominant missense variants, resulting in single amino acid residue substitutions in the C-type lectin repeat of the aggrecan G3 domain"
    explanation: >
      Identifies the shared molecular lesion (autosomal dominant ACAN
      missense variants in the aggrecan G3 domain C-type lectin repeat)
      across families with familial osteochondritis dissecans.
  - reference: PMID:35338222
    reference_title: "Novel missense ACAN gene variants linked to familial osteochondritis dissecans cluster in the C-terminal globular domain of aggrecan."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "this supports a link between missense ACAN variants affecting the aggrecan G3 domain and hereditary osteochondritis dissecans"
    explanation: >
      Functional secretion and ligand-binding assays on recombinant variant
      aggrecan protein support the causal link between G3-domain ACAN
      missense variants and hereditary osteochondritis dissecans.
environmental:
- name: Secondhand Tobacco Smoke Exposure
  presence: Possible
  description: >
    Household secondhand smoke exposure is a significant, dose-associated risk
    factor for Legg-Calve-Perthes disease in a prospective case-control study;
    proposed to represent an "unknown industrial factor" acting on the same
    ischemic mechanism as the articular family (e.g., via vasoconstriction or
    impaired microcirculation), though a firm mechanistic link is not
    established. No ECTO term for secondhand/environmental tobacco smoke
    exposure was found in the local cache or via a targeted OAK search at
    curation time.
  evidence:
  - reference: PMID:15599226
    reference_title: "Smoking and socio-economic status in the etiology and severity of Legg-Calvé-Perthes' disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A significant association was noted between living with a smoker and Legg-Calvé-Perthes disease as well as between increasing smoke exposure and increased risk of developing Legg-Calvé-Perthes disease."
    explanation: >
      Establishes that household second-hand smoke exposure is itself a
      documented exposure in this disease, with a dose-response relationship.
      This attests the exposure entry; the separate evidence on the
      influences_mechanisms link attests the claim that it acts on the
      ischemic chondronecrosis node.
  influences_mechanisms:
  - target: Cartilage-Canal Ischemic Chondronecrosis
    environmental_effect: PREDISPOSES
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >
      Second-hand smoke exposure is proposed to predispose to the ischemic
      chondronecrosis underlying Legg-Calve-Perthes disease, though the
      intermediate vascular mechanism has not been established.
    evidence:
    - reference: PMID:15599226
      reference_title: "Smoking and socio-economic status in the etiology and severity of Legg-Calvé-Perthes' disease."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The presence of second-hand smoke seems to be a significant risk factor in the development of Legg-Calvé-Perthes disease."
      explanation: >
        Prospective case-control study reporting a significant association
        between household secondhand smoke exposure and Legg-Calve-Perthes
        disease.
- name: Repetitive Sports-Related Mechanical Loading
  presence: Common
  description: >
    Repetitive tensile/traction loading from running and jumping sports
    during a growth spurt is the dominant recognized exposure across the
    non-articular apophyseal family (Osgood-Schlatter disease, Sever disease)
    and is also reported as the single most common precipitating exposure
    for osteochondritis dissecans of the articular family, alongside genetic
    predisposition, ischemia, and obesity.
  evidence:
  - reference: PMID:38671714
    reference_title: "Understanding Osteochondritis Dissecans: A Narrative Review of the Disease Commonly Affecting Children and Adolescents."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The most common cause of OCD is repetitive microtrauma, typically associated with sports activities, alongside other significant factors such as genetic predisposition, ischemia, and obesity."
    explanation: >
      Establishes that repetitive sports-related microtrauma is itself a
      documented, significant exposure across the osteochondrosis spectrum.
      This attests the exposure entry; the separate evidence on the
      influences_mechanisms link attests the specific claim that it triggers
      the apophyseal traction mechanism.
  influences_mechanisms:
  - target: Repetitive Traction Apophysitis
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >
      Repetitive running/jumping sports loading during a growth spurt is the
      proximate trigger for chronic tensile traction at the tibial
      tuberosity (Osgood-Schlatter disease) and calcaneal apophysis (Sever
      disease), distinct from the ischemic mechanism of the articular
      family.
    evidence:
    - reference: PMID:35742062
      reference_title: "Osgood-Schlatter Disease: Appearance, Diagnosis and Treatment: A Narrative Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "is linked to the practice of sports with an explosive component"
      explanation: >
        Directly links onset of the apophyseal traction mechanism to
        explosive/jumping sports activity.
- name: Childhood Obesity
  presence: Possible
  description: >
    Extreme childhood obesity is reported as a risk factor for
    osteochondritis dissecans across multiple joints (knee, ankle, elbow),
    independent of the repetitive-loading exposure above.
  evidence:
  - reference: PMID:38671714
    reference_title: "Understanding Osteochondritis Dissecans: A Narrative Review of the Disease Commonly Affecting Children and Adolescents."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "There is an established link between childhood obesity and the occurrence of OCD in the knees, ankles, and elbows of children."
    explanation: >
      Establishes childhood obesity as a documented exposure associated with
      osteochondritis dissecans across multiple joints.
  influences_mechanisms:
  - target: Cartilage-Canal Ischemic Chondronecrosis
    environmental_effect: PREDISPOSES
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >
      Extreme obesity is reported to substantially increase the risk of
      osteochondritis dissecans, plausibly via increased mechanical loading
      of cartilage-canal-dependent epiphyseal sites, though the intermediate
      mechanism has not been established.
    evidence:
    - reference: PMID:38671714
      reference_title: "Understanding Osteochondritis Dissecans: A Narrative Review of the Disease Commonly Affecting Children and Adolescents."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Research by Kessler et al. indicates that extremely obese patients face an 86% increased risk of developing any type of OCD compared to individuals of normal weight"
      explanation: >
        Quantifies the increased risk of osteochondritis dissecans
        associated with extreme obesity.
diagnosis:
- name: Plain Radiography
  diagnosis_term:
    preferred_term: X-ray imaging
    term:
      id: NCIT:C38101
      label: X-Ray Imaging
  description: >
    Plain radiographs are first-line for detecting the characteristic
    sclerosis, flattening, fragmentation, wedging, or irregularity at the
    affected epiphysis or apophysis across the osteochondrosis family, and are
    usually sufficient for a clinical diagnosis of the apophyseal subtypes
    (Osgood-Schlatter disease, Sever disease).
  evidence:
  - reference: PMID:28722957
    reference_title: "Sever Disease (Calcaneal Apophysitis)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The diagnosis of Sever disease is primarily clinical and does not necessitate imaging studies. However, plain radiographs can assist in ruling out bone fractures"
    explanation: >
      Confirms that the apophyseal subtypes are diagnosed clinically, with
      radiography reserved to exclude alternative diagnoses.
- name: Magnetic Resonance Imaging
  diagnosis_term:
    preferred_term: magnetic resonance imaging
    term:
      id: NCIT:C16809
      label: Magnetic Resonance Imaging
  description: >
    MRI is used when radiographs are normal or equivocal, particularly early
    in the articular family (before radiographic sclerosis/fragmentation is
    visible) and to stage osteochondritis dissecans lesions by cartilage and
    subchondral bone integrity.
  evidence:
  - reference: PMID:34109940
    reference_title: "Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Diagnosis is based on the history, physical examination, radiography, and advanced imaging, with elbow ultrasonography and novel magnetic resonance imaging protocols potentially enabling early detection and in-depth staging."
    explanation: >
      Establishes advanced MRI protocols as tools for early detection and
      lesion staging in osteochondritis dissecans.
treatments:
- name: Activity Modification and Relative Rest
  description: >
    First-line conservative management across nearly all osteochondrosis
    subtypes: reduction of the offending sport/activity load, with symptom
    resolution typically following once loading is reduced or the growth
    plate/apophysis fuses.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: supportive care
    term:
      id: NCIT:C15747
      label: Supportive Care
  target_phenotypes:
  - preferred_term: Knee pain
    term:
      id: HP:0030839
      label: Knee pain
  - preferred_term: Foot pain
    term:
      id: HP:0025238
      label: Foot pain
  evidence:
  - reference: PMID:28722957
    reference_title: "Sever Disease (Calcaneal Apophysitis)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Sever disease typically follows a self-limited course, and its management involves activity modification or relative rest in response to pain."
    explanation: >
      Establishes activity modification/relative rest as first-line
      management for the apophyseal osteochondrosis family.
  - reference: PMID:35740763
    reference_title: "The Etiology and Risk Factors of Osgood-Schlatter Disease: A Systematic Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The treatment is usually conservative, but some surgical options can be considered when conservative treatment fails or in some limited cases."
    explanation: >
      Confirms conservative management as first-line, with surgery reserved
      for refractory cases.
- name: Femoral Head Containment (Bracing or Osteotomy)
  description: >
    In Legg-Calve-Perthes disease, biomechanical containment of the femoral
    head within the acetabulum (via bracing or surgical osteotomy) aims to
    preserve a spherical joint surface while revascularization and remodeling
    occur, though multicenter studies report only modest success in older
    children.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: orthopedic surgical procedure
    term:
      id: NCIT:C16186
      label: Orthopedic Surgical Procedure
  target_mechanisms:
  - target: Revascularization and Remodeling under Mechanical Load
    treatment_effect: MODULATES
    description: >
      Containment surgery is intended to redistribute mechanical load on the
      healing femoral head so that remodeling produces a spherical joint
      surface rather than progressive deformity.
  target_phenotypes:
  - preferred_term: Hip pain
    term:
      id: HP:0030838
      label: Hip pain
  evidence:
  - reference: PMID:22488623
    reference_title: "Pathophysiology and new strategies for the treatment of Legg-Calvé-Perthes disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "current nonoperative and operative treatments have modest success rates of producing a good outcome with a spherical femoral head in older children with Legg-Calvé-Perthes disease"
    explanation: >
      Reports only modest success for current containment strategies in
      older children, so support is treated as partial rather than full.
- name: Surgical Excision, Fixation, or Retroarticular Drilling
  description: >
    Unstable osteochondritis dissecans lesions (with articular cartilage
    fracture or subchondral bone separation) that fail conservative
    management in skeletally immature patients are managed operatively;
    treatment choice depends on skeletal maturity and lesion stability.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: surgical procedure
    term:
      id: NCIT:C15329
      label: Surgical Procedure
  target_mechanisms:
  - target: Delayed Endochondral Ossification and Necrotic Fragmentation
    treatment_effect: MODULATES
    description: >
      Surgical fixation or drilling of an unstable osteochondritis dissecans
      lesion is intended to promote healing of the fragmented subchondral
      bone/cartilage rather than progression to a loose body.
  evidence:
  - reference: PMID:34109940
    reference_title: "Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Treatment largely depends on skeletal maturity and lesion stability, defined by the presence or absence of articular cartilage fracture and subchondral bone separation, as determined by imaging and arthroscopy, and is typically nonoperative for stable lesions in skeletally immature patients and operative for those who have had failure of conservative management or have unstable lesions."
    explanation: >
      Establishes the maturity/stability-dependent decision between
      nonoperative and operative management of osteochondritis dissecans.
  - reference: PMID:37039536
    reference_title: "Transarticular Versus Retroarticular Drilling of Stable Osteochondritis Dissecans of the Knee: A Prospective Multicenter Randomized Controlled Trial by the ROCK Group."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Healing parameters were superior at 6 months and 12 months in the TAD group, compared with the RAD group"
    explanation: >
      Prospective multicenter randomized controlled trial (ROCK Group, Level
      of evidence 1, n=91) directly comparing the two drilling techniques
      named in this treatment and reporting superior early healing with
      transarticular over retroarticular drilling.
- name: Thoracolumbosacral Orthosis Bracing
  description: >
    Bracing (TLSO) is used for skeletally immature patients with symptomatic
    or progressive Scheuermann kyphosis to limit curve progression during
    remaining growth; surgery is reserved for large, progressive, symptomatic
    deformity.
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: therapeutic procedure
    term:
      id: NCIT:C49236
      label: Therapeutic Procedure
  target_phenotypes:
  - preferred_term: Kyphosis
    term:
      id: HP:0002808
      label: Kyphosis
  evidence:
  - reference: PMID:37615931
    reference_title: "Scheuermann Kyphosis: Current Concepts and Management."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Nonoperative treatment consists of physical therapy in symptomatic patients, and bracing can be added for skeletally mature patients. Operative management can be considered in patients with large, progressive, and symptomatic deformity."
    explanation: >
      Describes the stepwise nonoperative-to-operative management pathway for
      Scheuermann kyphosis.
clinical_trials:
- name: NCT01754298
  phase: NOT_APPLICABLE
  status: COMPLETED
  description: >
    Prospective multicenter randomized controlled trial (the ROCK Group, 14
    centers, 17 surgeon-investigators) comparing transarticular drilling (TAD)
    against retroarticular drilling (RAD) for stable osteochondritis dissecans
    lesions of the medial femoral condyle in skeletally immature patients who
    had failed at least 3 months of nonoperative treatment.
  target_phenotypes:
  - preferred_term: Osteochondritis dissecans
    term:
      id: HP:0010886
      label: Osteochondritis dissecans
  evidence:
  - reference: PMID:37039536
    reference_title: "Transarticular Versus Retroarticular Drilling of Stable Osteochondritis Dissecans of the Knee: A Prospective Multicenter Randomized Controlled Trial by the ROCK Group."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Randomized controlled clinical trial; Level of evidence, 1."
    explanation: >
      States the trial design and evidence level for this head-to-head
      comparison of the two drilling techniques modeled in the
      "Surgical Excision, Fixation, or Retroarticular Drilling" treatment.
  - reference: PMID:37039536
    reference_title: "Transarticular Versus Retroarticular Drilling of Stable Osteochondritis Dissecans of the Knee: A Prospective Multicenter Randomized Controlled Trial by the ROCK Group."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A total of 91 patients were included, consisting of 51 patients in the TAD and 40 patients in the RAD group, who were similar in age, sex distribution, and 2-year PRO response rate."
    explanation: >
      Reports the trial's enrolled population size and randomization arms.
discussions:
- discussion_id: osteochondrosis_animal_ischemia_human_translation
  prompt: >-
    Does the ischemic-chondronecrosis mechanism, reproduced causally in foals
    and other model organisms, generalize to all sites and severities of human
    articular osteochondrosis, or only to the specific predilection sites and
    ages examined so far?
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  attaches_to:
  - pathophysiology#Cartilage-Canal Ischemic Chondronecrosis
  rationale: >-
    The causal experiment for cartilage-canal vessel failure -> ischemic
    chondronecrosis -> osteochondrosis -> osteochondrosis dissecans was
    performed by surgically transecting vessels in the femoro-patellar joint
    of foals (PMID:23428601), an equine model with different growth-plate
    biology, cartilage-canal anatomy, and loading regime than the pediatric
    human knee/hip/foot. The strongest human bridging evidence
    (PMID:30248503) is limited to CT/histology of pediatric knee predilection
    sites in cadaveric/postmortem specimens (13 children, 1 month to 11 years
    old), not living-patient longitudinal data, and to the knee specifically
    rather than the hip (Perthes), navicular (Kohler), or metatarsal head
    (Freiberg) sites also attributed to this mechanism.
  proposed_experiments:
  - experiment_id: exp_osteochondrosis_multisite_human_histology
    name: Multi-site human cartilage-canal histology across the articular
      osteochondrosis family
    description: >-
      Extend the pediatric-knee CT/histology approach (PMID:30248503) to
      cadaveric or surgical specimens from the femoral head, tarsal navicular,
      and second metatarsal head predilection sites, at ages spanning the
      typical clinical onset for Perthes, Kohler, and Freiberg disease
      respectively, to test whether the same ischemic-chondronecrosis
      signature is present at each site.
  evidence:
  - reference: PMID:23428601
    reference_title: "Transection of vessels in epiphyseal cartilage canals leads to osteochondrosis and osteochondrosis dissecans in the femoro-patellar joint of foals; a potential model of juvenile osteochondritis dissecans."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "There are several similarities between OCD in animals and JOCD in children. It should be investigated whether JOCD also occurs due to a focal failure in the cartilage canal blood supply, followed by ischaemic chondronecrosis."
    explanation: >-
      The authors themselves frame the human translation as a question still
      to be investigated at the time of publication, not an established fact.
- discussion_id: perthes_etiology_undetermined
  prompt: >-
    Is mechanically induced ischemia sufficient to explain Legg-Calve-Perthes
    disease, or does the disease require an additional predisposing factor
    (thrombophilic, genetic, or environmental) in most cases?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Cartilage-Canal Ischemic Chondronecrosis
  rationale: >-
    A systematic review of 64 articles on LCPD etiology found no single
    decisive theory: mechanically induced ischemia is the best-supported, twin
    studies argue against a major role for common genetic factors, and a
    congenital or acquired predisposition cannot be excluded. This entry
    therefore models the thrombophilia (F5/F2), Mendelian COL2A1 phenocopy,
    and secondhand-smoke environmental associations as contributing risk
    factors rather than as components of a single confirmed causal chain.
  evidence:
  - reference: PMID:30918798
    reference_title: "Aetiology of Legg-Calvé-Perthes disease: A systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Several hypotheses have been researched, but none of them was found decisive."
    explanation: >-
      States directly that no single etiologic hypothesis for LCPD has been
      established as decisive.
review_notes: >
  Curated for issue #8963 (CURATE_ROOT_WITH_SUBTYPES, MONDO:0018381). Modeled
  as a Disease with has_subtypes by site, per the issue's explicit instruction,
  rather than as a Grouping, even though the three constituent mechanistic
  families (articular/ischemic, apophyseal/traction, physeal/compressive) are
  not unified by a single shared mechanism — this is recorded structurally by
  giving each family its own top-level pathophysiology chain tagged with the
  relevant `subtypes:` rather than chaining all subtypes downstream of one
  ischemic cascade. Kohler disease (MONDO:0016086) is linked by name, not
  duplicated, per its existing standalone entry
  (Osteochondritis_of_Tarsal_Metatarsal_Bone.yaml), which already declares
  `parents: [Osteochondrosis, Pediatric Foot Disease]`. Osteochondritis
  dissecans (MONDO:0017178) is included as a has_subtypes member per the issue,
  which is a deliberate divergence from MONDO's own parent assignment (child of
  MONDO:0018383 osteonecrosis of genetic origin, not of MONDO:0018381
  osteochondrosis); see that subtype's own `review_notes`. Sever disease has no
  MONDO term (confirmed absent by OAK search at curation time) and is modeled
  with a free-text `subtype_term`. Kienbock disease, Panner disease, Thiemann
  disease, Sinding-Larsen-Johansson disease, and medial condensing osteitis of
  the clavicle are additional MONDO children of osteochondrosis not named in
  the curation issue and are intentionally out of scope for this entry.
  MONDO:0010130 (dihydropyrimidine dehydrogenase deficiency), also listed as an
  OLS hierarchical child of MONDO:0018381 in upstream research, appears to be a
  MONDO placement error (it is an unrelated pyrimidine-catabolism disorder,
  already curated separately as Dihydropyrimidine_Dehydrogenase_Deficiency.yaml)
  and is excluded here rather than propagated. ORPHA:399319 (the Orphanet
  group-of-disorders entry for osteochondrosis) was confirmed not present in
  references_cache/ and not fetchable as a leaf-disorder evidence source, so no
  ORPHA: evidence was cited; all evidence in this entry is PMID-sourced.
📚

References & Deep Research

Deep Research

1
Falcon ▸
Disease Characteristics Research Template
Edison Scientific Literature 14 citations 2026-08-26T22:24:54.236095

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

  • Disease Name: Osteochondrosis
  • MONDO ID: (if available)
  • Category: Complex

Research Objectives

Please provide a comprehensive research report on Osteochondrosis covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

  • What is the disease? Provide a concise overview.
  • What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
  • What are the common synonyms and alternative names?
  • Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

  • Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
  • Risk Factors:

    Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases

  • Genetic risk factors (causal variants, susceptibility loci, modifier genes)
  • Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
  • Protective Factors:

    Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases

  • Genetic protective factors (protective variants, modifier alleles)
  • Environmental protective factors (diet, lifestyle, exposures that reduce risk)
  • Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

    Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

  • Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

    Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene

  • Pathogenic Variants:
  • Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
  • Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
  • Variant type/class (missense, frameshift, nonsense, splice-site, structural)
  • Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
  • Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
  • Functional consequences (loss of function, gain of function, dominant negative)
  • Modifier Genes: Genes that modify disease severity or expression
  • Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

    Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

  • Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

    Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases

  • Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

    Search first: CDC databases, WHO, PubMed, NHANES

  • Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

    Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

  • Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

    Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc

  • Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

    Search first: Gene Ontology (GO), Reactome, KEGG, PubMed

  • Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

    Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold

  • Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

    Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA

  • Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

    Search first: ImmPort, Immunome Database, IEDB, Gene Ontology

  • Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

    Search first: PubMed, Gene Ontology, Reactome

  • Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

    Search first: BRENDA, UniProt, KEGG, OMIM, PubMed

  • Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Molecular Profiling (if available):
  • Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
  • Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
  • Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
  • Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
  • Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
  • Advanced Technologies (if applicable):
  • Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
  • Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
  • Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
  • Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

  • Organ Level:
  • Primary organs directly affected
  • Secondary organ involvement (complications, secondary effects)
  • Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

    Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT

  • Tissue and Cell Level:
  • Specific tissue types affected (epithelial, connective, muscle, nervous)
  • Specific cell populations targeted (with Cell Ontology terms)

    Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB

  • Subcellular Level:
  • Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

    Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas

  • Localization:
  • Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
  • Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

  • Onset:
  • Typical age of onset (congenital, pediatric, adult, geriatric)
  • Onset pattern (acute, subacute, chronic, insidious)

    Search first: OMIM, Orphanet, HPO, PubMed

  • Progression:
  • Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
  • Progression rate (rapid, slow, variable)
  • Disease course pattern (episodic, relapsing-remitting, progressive, stable)
  • Disease duration (self-limited, chronic lifelong)

    Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM

  • Patterns:
  • Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
  • Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

  • Epidemiology:
  • Prevalence (cases per 100,000 at given time)
  • Incidence (new cases per 100,000 per year)

    Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries

  • For Genetic Etiology:
  • Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
  • Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
  • Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
  • Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
  • Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
  • Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
  • Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
  • Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
  • Population Demographics:
  • Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
  • Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
  • Geographic distribution of specific variants
  • Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
  • Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

  • Clinical Tests:
  • Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
  • Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
  • Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
  • Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
  • Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
  • Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
  • Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
  • Genetic Testing:

    Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen

  • Overview of recommended genetic testing approach
  • Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
  • Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
  • Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
  • Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
  • Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
  • Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
  • FISH > Search first: ClinVar, cytogenetics databases, PubMed
  • Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
  • Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
  • Omics-Based Diagnostics (if applicable):
  • RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
  • Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
  • Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
  • Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
  • Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
  • Clinical Criteria:
  • Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
  • Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
  • Screening:
  • Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

  • Survival and Mortality:
  • Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
  • Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
  • Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
  • Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
  • Morbidity and Function:
  • Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
  • Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
  • Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
  • Disease Course:
  • Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
  • Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
  • Prediction:
  • Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
  • Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

  • Pharmacotherapy:
  • Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
  • Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
  • Advanced Therapeutics:
  • Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
  • Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
  • RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
  • Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
  • Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
  • Surgical and Interventional:
  • Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
  • Supportive and Rehabilitative:
  • Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
  • Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
  • Experimental:
  • Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
  • Treatment Outcomes:
  • Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
  • Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
  • Treatment Strategy:
  • Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
  • Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
  • Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest NCIT (NCI Thesaurus) clinical-intervention terms where applicable.

13. Prevention

  • Prevention Levels:
  • Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
  • Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
  • Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
  • Immunization: Vaccine strategies (if applicable)

    Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database

  • Screening and Early Detection:
  • Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
  • Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
  • Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
  • Behavioral Interventions: Lifestyle modifications to reduce risk

    Search first: CDC, WHO, behavioral intervention databases, Cochrane Library

  • Counseling: Genetic counseling (risk assessment, family planning guidance)

    Search first: NSGC resources, ACMG guidelines, GeneReviews

  • Public Health:
  • Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
  • Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
  • Prophylaxis: Preventive medications or procedures

    Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

  • Taxonomy: Species affected (with NCBI Taxon identifiers)

    Search first: NCBI Taxonomy

  • Breed: Specific breeds affected (with VBO identifiers if applicable)

    Search first: VBO (Vertebrate Breed Ontology)

  • Gene: Orthologous genes in other species (with NCBI Gene IDs)

    Search first: NCBI Gene

  • Natural Disease:
  • Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
  • Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
  • Comparative Biology:
  • Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
  • Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
  • Transmission (if applicable):
  • Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
  • Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

  • Model Types:
  • Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
  • Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
  • Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
  • Genetic Models:
  • Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
  • Model Characteristics:
  • Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
  • Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
  • Applications:
  • Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
  • Resources:
  • Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

  • Cite primary literature (PMID preferred) for all mechanistic and clinical claims
  • Prioritize recent reviews and landmark papers
  • Include direct quotes from abstracts where possible to support key statements
  • Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, NCIT, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (NCIT terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Osteochondrosis: comprehensive disease-characteristics report

Executive summary and scope

Osteochondrosis is not one homogeneous disease. In its strict developmental-articular sense, it is a focal disturbance of endochondral ossification in the growing skeleton. Failure of blood supply to epiphyseal cartilage produces chondronecrosis and arrested ossification; mechanical loading may then cause clefting, collapse, an unstable osteochondral fragment, and clinically recognized osteochondritis dissecans (OCD). The term is also applied to anatomically distinct juvenile disorders—such as Legg–Calvé–Perthes, Osgood–Schlatter, Sever, Freiberg, Köhler, and Scheuermann diseases—and, especially in Europe, to adult degenerative spinal disease. These should not be merged into one knowledge-base record. This report therefore focuses on developmental articular osteochondrosis/OCD, with other named osteochondroses treated as related but separate entities. (mccoy2013articularosteochondrosisa pages 7-8, mccoy2013articularosteochondrosisa pages 2-4, mccoy2013articularosteochondrosisa pages 1-2)

Entity/scope Defining biology Typical age/sites KB handling
Developmental articular osteochondrosis (latent/manifesta stages) Focal disturbance/failure of endochondral ossification in growing epiphyseal or articular-epiphyseal cartilage, linked to cartilage-canal vascular failure and localized chondronecrosis; latent/manifesta represent pre-fracture stages before instability or dissection becomes clinically obvious (mccoy2013articularosteochondrosisa pages 7-8, mccoy2013articularosteochondrosisa pages 2-4, mccoy2013articularosteochondrosisa pages 5-7, mccoy2013articularosteochondrosisa pages 1-2, edmonds2023evaluatingtheetiology pages 1-3) Usually children/adolescents; classic sites include knee, elbow/capitellum, ankle/talus and other developing joints (konarski2024understandingosteochondritisdissecans pages 1-2, konarski2024understandingosteochondritisdissecans pages 2-3) Use as the core disease-family concept for developmental articular lesions; record latent/manifesta as upstream pathobiology or stage terms rather than separate unrelated diseases
Osteochondritis dissecans (OCD) Fissured/unstable or fragmenting stage of articular osteochondrosis in which the osteochondral surface becomes unstable, may cleave/dissect, and causes pain, swelling, catching, or locking; often the stage recognized clinically in humans (konarski2024understandingosteochondritisdissecans pages 1-2, mccoy2013articularosteochondrosisa pages 7-8, mccoy2013articularosteochondrosisa pages 2-4, konarski2024understandingosteochondritisdissecans pages 12-13) Predominantly children/adolescents; most often knee, then elbow and ankle; juvenile form has open physes and better healing potential than adult form (konarski2024understandingosteochondritisdissecans pages 1-2, konarski2024understandingosteochondritisdissecans pages 2-3, konarski2024understandingosteochondritisdissecans pages 12-13) Represent as a child concept or advanced-stage concept under articular osteochondrosis, with site-specific subrecords (knee OCD, capitellar OCD, talar OCD) when anatomy-specific details differ
Named juvenile osteochondroses (e.g., Legg-Calvé-Perthes, Osgood-Schlatter, Sever, Freiberg, Köhler, Scheuermann) Site-specific pediatric osteochondrosis labels used for distinct anatomic syndromes; they should not be automatically merged with articular osteochondrosis/OCD because biology, anatomy, imaging, natural history, and management differ by entity Childhood/adolescence; hip/femoral head, tibial tubercle, calcaneal apophysis, metatarsal head, navicular, vertebral endplates depending on syndrome Curate as separate disease records linked by broader “juvenile osteochondrosis/osteochondrosis” family membership; avoid pooling epidemiology or genetics across these entities without direct evidence
Adult spinal “osteochondrosis” terminology Commonly used degenerative spine terminology rather than the pediatric developmental articular-osteochondrosis process; usage may refer to vertebral endplate/disc degeneration or historical naming conventions rather than OCD biology Mainly adolescents/adults in the spine, especially thoracic/lumbar vertebral endplates/discs in clinical radiology/orthopedics usage Keep separate from developmental articular osteochondrosis/OCD in the knowledge base unless a source explicitly addresses Scheuermann-type juvenile vertebral osteochondrosis; do not merge adult degenerative spine usage with pediatric OCD biology

Table: This table clarifies how “osteochondrosis” should be scoped in a knowledge base to avoid conflating developmental articular osteochondrosis/OCD with named juvenile osteochondroses or adult degenerative spinal terminology. It is useful for deciding when to create a parent concept versus separate site-specific disease records.

Evidence base. The strongest recent sources retrieved were a 2024 clinical review, a 2023 longitudinal MRI study of lesion development, and the registry record/publication metadata for a 2023 prospective multicenter randomized drilling trial. Mechanistic evidence also relies on a highly cited 2013 comparative pathology review because early human tissue is rarely available. PMID values were not exposed in the retrieved records; DOI links are supplied rather than inventing PMIDs.

1. Disease information

Definition

Articular osteochondrosis is a developmental disorder of epiphyseal growth cartilage in which focal failure of endochondral ossification creates an abnormally retained, often necrotic cartilage region. Veterinary pathology recognizes a continuum:

  1. Osteochondrosis latens: microscopic cartilage necrosis, not radiographically visible.
  2. Osteochondrosis manifesta: retained cartilage or an ossification defect visible radiographically.
  3. Osteochondrosis dissecans/osteochondritis dissecans: fissuring through cartilage, instability, or separation of an osteochondral fragment.

Human patients are commonly recognized only at the symptomatic OCD stage. “Osteochondritis” is historically entrenched but potentially misleading because primary inflammation is not established; “osteochondrosis dissecans” better reflects the developmental-necrotic process. (mccoy2013articularosteochondrosisa pages 7-8, mccoy2013articularosteochondrosisa pages 2-4, mccoy2013articularosteochondrosisa pages 5-7)

A current clinical definition describes OCD as a focal idiopathic subchondral-bone alteration that threatens articular-surface stability and can culminate in premature osteoarthritis. It primarily affects the knee, elbow, and ankle of children and adolescents. (konarski2024understandingosteochondritisdissecans pages 1-2)

Identifiers and terminology

  • OMIM 165800: familial osteochondritis dissecans, associated with ACAN. This is a rare Mendelian subtype, not an identifier for all sporadic osteochondrosis. (mccoy2013articularosteochondrosisa pages 5-7)
  • MONDO: the exact current MONDO accession was not verified in the retrieved evidence and should be resolved directly against the current MONDO release. Do not assign the osteochondritis-dissecans concept to every named juvenile osteochondrosis.
  • MeSH: Osteochondritis Dissecans is the appropriate literature-indexing concept for clinically dissecting lesions; site-specific juvenile osteochondroses have separate concepts where available.
  • ICD-10-CM: OCD is generally coded within M93.2- (“osteochondritis dissecans”), with site/laterality extensions; other juvenile osteochondroses fall within M91–M93. Exact national extensions must be validated against the implementation in use.
  • ICD-11, SNOMED CT, Orphanet: use current terminology-service lookups at ingestion. A single Orphanet/OMIM record does not encompass common multifactorial articular OCD.
  • Synonyms: articular osteochondrosis; osteochondritis dissecans; osteochondrosis dissecans; juvenile OCD/JOCD; adult OCD/AOCD; dissecting osteochondritis.

The evidence summarized here is aggregated disease-level literature, not individual-patient EHR data. The 2023 etiologic study is a small patient-level imaging cohort subsequently aggregated for analysis. (edmonds2023evaluatingtheetiology pages 1-3)

Exact abstract quotation—2024 review: “OCD is a joint disorder predominantly affecting the knee, elbow, and ankle of children and adolescents.” (konarski2024understandingosteochondritisdissecans pages 1-2)

2. Etiology

Causal and susceptibility factors

Osteochondrosis/OCD is usually multifactorial. The best-supported causal model combines developmental vascular vulnerability with mechanical loading:

  • Developmental vascular failure: interruption of cartilage-canal blood supply causes focal chondrocyte death and failed ossification.
  • Repetitive microtrauma/overuse: particularly jumping, pivoting, and repetitive throwing. Contemporary clinical literature regards sports-associated repetitive microtrauma as the commonest precipitating exposure.
  • Local ischemia: predilection sites have vulnerable vascular anatomy.
  • Growth and skeletal immaturity: lesions arise during active epiphyseal ossification.
  • Obesity: extreme childhood obesity was associated with an 86% higher risk in the epidemiologic evidence summarized by the 2024 review.
  • Genetic predisposition: familial aggregation, concordance in identical twins, rare monogenic ACAN disease, and candidate associations on chromosomes 7 and 13 support inherited susceptibility. Evidence for common sporadic variants remains limited. (konarski2024understandingosteochondritisdissecans pages 2-3, mccoy2013articularosteochondrosisa pages 5-7)

Trauma should be interpreted carefully. Comparative pathology suggests that loading may provoke symptoms or convert a pre-existing necrotic lesion into a fissure, rather than always initiating the earliest lesion. Thus, vascular injury is upstream, while repetitive stress often acts as a lesion-progressing factor. (mccoy2013articularosteochondrosisa pages 5-7)

Protective factors

No validated protective human allele or disease-specific protective diet is established. Plausible environmental protection consists of avoiding excessive repetitive joint loading during vulnerable growth periods, maintaining healthy body mass, varying youth sports, and responding promptly to persistent activity-related joint pain. These are risk-reduction principles, not interventions proven to abolish disease. Animal evidence implicates copper deficiency, excess phosphorus, and excessive dietary energy, but comparable human nutrition studies were not identified. (mccoy2013articularosteochondrosisa pages 5-7)

Gene–environment interaction

The working model is that genetically influenced matrix quality, vascular anatomy, growth velocity, or endochondral-ossification resilience modifies the effect of mechanical load. In rare ACAN-related disease, abnormal aggrecan weakens cartilage-matrix function; in common sporadic disease, polygenic susceptibility may determine why only some heavily exposed young athletes develop lesions. Definitive human G×E effect estimates are unavailable. (mccoy2013articularosteochondrosisa pages 5-7)

3. Phenotypes

Phenotype Type and characteristics Suggested HPO term
Activity-related joint pain Earliest common symptom; vague and poorly localized, initially intermittent and later persistent HP:0002829 Arthralgia
Joint swelling/effusion Usually activity-associated; may become recurrent HP:0001373 Joint swelling
Joint stiffness/restricted movement More evident with progression HP:0001387 Joint stiffness, HP:0001376 Limitation of joint mobility
Catching or locking Mechanical symptom suggesting flap/fragment instability HP:0011743 Joint locking if accepted in local HPO release
Reduced function/limp Site dependent; lower-extremity lesions impair walking, running, and sport HP:0002355 Difficulty walking, HP:0002750 Delayed skeletal maturation only when documented
Osteochondral defect/subchondral lesion Imaging/structural phenotype HP:0033126 Osteochondritis dissecans if available in the deployed HPO release
Early secondary osteoarthritis Late complication of persistent or unstable disease HP:0002758 Osteoarthritis

Onset is usually in childhood or adolescence and peaks around early-to-mid adolescence. Severity ranges from asymptomatic radiographic lesions to severe pain, recurrent effusion, locking, and disability. Bilateral disease occurs but is usually asymmetric. No characteristic behavioral, hematologic, biochemical, or systemic laboratory phenotype exists in isolated disease. (konarski2024understandingosteochondritisdissecans pages 1-2, mccoy2013articularosteochondrosisa pages 2-4)

Quality of life: pain interferes with physical function, school sports, competitive participation, and sometimes ordinary walking. Long-term cartilage loss can create chronic pain and early osteoarthritis. Disease-specific EQ-5D or SF-36 population estimates were not identified; orthopedic studies commonly use IKDC, KOOS, Lysholm, activity scales, and site-specific scores. (konarski2024understandingosteochondritisdissecans pages 12-13)

4. Genetic and molecular information

Established and candidate genes

  • ACAN encodes aggrecan, a major cartilage extracellular-matrix proteoglycan. Heterozygous germline pathogenic variants can cause autosomal-dominant familial OCD (OMIM 165800), often with disproportionate short stature and early osteoarthritis. Variant-specific HGVS, ClinVar classification, and gnomAD frequency must be curated from the individual family report; there is no single common causal ACAN allele. The inferred mechanism is altered aggrecan matrix organization/function. (mccoy2013articularosteochondrosisa pages 5-7)
  • COMP: a 2024 clinical report expanded the phenotype of COMP-related multiple epiphyseal dysplasia to include multiple OCD lesions. This establishes OCD as a possible manifestation of a broader skeletal dysplasia, not COMP as a common cause of isolated sporadic OCD.
  • COL9A2, and more broadly COL9A1/COL9A2/COL9A3, are relevant when OCD co-occurs with multiple epiphyseal dysplasia; knee-predominant disease has been described in collagen-IX-associated MED.
  • Common sporadic OCD appears polygenic. Candidate signals on chromosomes 7 and 13 are hypothesis-generating and are not diagnostic loci. (konarski2024understandingosteochondritisdissecans pages 2-3, mccoy2013articularosteochondrosisa pages 5-7)

Variant interpretation

For a patient with isolated, unilateral, sports-associated OCD, routine molecular testing has low expected yield. Testing becomes appropriate for multifocal or bilateral disease, short stature, epiphyseal dysplasia, premature generalized osteoarthritis, or a strong family history. A skeletal-dysplasia panel should include ACAN, COMP, COL9A1, COL9A2, and COL9A3, with phenotype-driven expansion. WES/WGS may be considered after negative panel testing in strongly familial disease. CMA, karyotype, FISH, mitochondrial testing, and repeat-expansion testing are not routine without additional syndromic evidence.

No recurrent chromosomal abnormality, somatic mutation, pharmacogenomic marker, proven modifier gene, or clinically validated epigenetic signature is established for common articular osteochondrosis. Allele frequency and ACMG status are variant-specific and should never be assigned at gene level.

5. Environmental information

Relevant exposures are biomechanical rather than toxic or infectious:

  • intensive repetitive sport during growth;
  • overhead throwing for capitellar lesions;
  • basketball and soccer participation for knee lesions;
  • high body mass/mechanical loading;
  • possible malalignment or site-specific biomechanics.

Smoking, alcohol, pollution, ionizing radiation, occupational toxins, and infectious agents are not established primary causes of developmental articular osteochondrosis. The disorder is not contagious, vaccine-preventable, or zoonotic. Nutritional abnormalities are supported mainly in livestock models and should not be extrapolated directly to children. (konarski2024understandingosteochondritisdissecans pages 2-3, mccoy2013articularosteochondrosisa pages 5-7)

6. Mechanism and pathophysiology

Causal chain

  1. Growing epiphyseal cartilage depends on cartilage-canal vessels. During development, blood supply transitions from perichondrial vessels toward medullary vessels.
  2. Vascular interruption or failed vascular transition produces focal ischemia.
  3. Chondronecrosis develops around affected canals.
  4. Necrotic cartilage fails to undergo normal endochondral ossification, creating retained cartilage and an irregular subchondral-bone front.
  5. Continued growth and mechanical loading cause resorption, collapse, clefting, and sequestrum formation.
  6. A stable lesion may heal through revascularization; a narrow, avascular attachment is prone to instability and dissection.
  7. Fragmentation damages the articular surface, producing pain, effusion, mechanical locking, and ultimately secondary osteoarthritis. (mccoy2013articularosteochondrosisa pages 7-8, mccoy2013articularosteochondrosisa pages 9-11, mccoy2013articularosteochondrosisa pages 5-7)

The 2023 longitudinal MRI study provides recent human support for a lesion arising at the articular–epiphyseal cartilage complex. Six children with seven knees had pre-OCD MRI at a median age of 11.6 years and follow-up about 1.9 years later. Every lesion increased in depth; depth changed significantly in coronal and sagittal planes (p=0.029 and p=0.026). Variable patterns—continued ossification, arrested progression, or regression near the lesion—support heterogeneous responses or multiple etiologic routes. (edmonds2023evaluatingtheetiology pages 1-3)

Cells, processes, and ontology suggestions

  • Cells: epiphyseal/articular chondrocytes (CL:0000138 chondrocyte), vascular endothelial cells (CL:0000115 endothelial cell), osteoblast-lineage cells (CL:0000062 osteoblast), osteoclasts (CL:0000092 osteoclast).
  • GO biological processes: endochondral ossification (GO:0001958), cartilage development (GO:0051216), blood-vessel development (GO:0001568), chondrocyte differentiation (GO:0002062), response to hypoxia (GO:0001666), cell death (GO:0008219), extracellular-matrix organization (GO:0030198), bone remodeling (GO:0046849).
  • Cellular compartments: extracellular matrix (GO:0031012), collagen-containing extracellular matrix (GO:0062023), aggrecan-rich cartilage matrix, and cell–matrix interfaces.

Primary immune autoimmunity is not established. Inflammation may occur downstream after fissuring or synovial irritation. No disease-specific metabolic, proteomic, lipidomic, single-cell, spatial-transcriptomic, CRISPR-screen, or multi-omic diagnostic signature has entered practice.

7. Anatomical structures affected

The principal structures are articular cartilage, epiphyseal growth cartilage, subchondral bone, and the osteochondral junction. Common sites are:

  • Knee: classically the lateral aspect of the medial femoral condyle; the medial femoral condyle accounts for approximately 66.2% of knee lesions.
  • Elbow: capitellum, particularly in throwing athletes.
  • Ankle: talar dome.
  • Less commonly: patella, trochlea, femoral head, shoulder, and multifocal sites. (konarski2024understandingosteochondritisdissecans pages 1-2, konarski2024understandingosteochondritisdissecans pages 2-3)

Suggested UBERON mappings include knee joint (UBERON:0001465), elbow joint (UBERON:0001461), ankle joint, articular cartilage (UBERON:0001997), epiphysis, subchondral bone, femoral condyle, capitulum of humerus, and talus; identifiers should be validated against the deployed UBERON release. Disease may be unilateral or bilateral, but bilateral lesions are often asymmetric. (mccoy2013articularosteochondrosisa pages 2-4)

8. Temporal development

Onset is insidious during skeletal growth. Early lesions may be asymptomatic and invisible on radiographs. Symptomatic progression typically moves from activity-related pain to recurrent swelling and stiffness, then catching/locking as instability develops. (konarski2024understandingosteochondritisdissecans pages 1-2, mccoy2013articularosteochondrosisa pages 2-4)

The practical stages are latent → manifesta → stable OCD → unstable/displaced OCD → secondary osteoarthritis. Skeletally immature patients with open physes have greater healing potential than adults. Animal and comparative evidence indicates a species-specific critical age after which persistent lesions are unlikely to resolve; in humans this corresponds broadly to diminishing healing potential as physeal closure approaches. Stable, broadly attached, vascularized lesions may heal, whereas narrow, avascular, unstable fragments seldom heal completely. (mccoy2013articularosteochondrosisa pages 9-11)

The principal intervention window is before physeal closure and before cartilage breach or fragment displacement. There is no relapsing-remitting systemic course; apparent remission generally reflects lesion healing or successful treatment.

9. Inheritance and population epidemiology

Epidemiology

Recent synthesis reports:

  • Knee OCD prevalence/incidence estimates vary substantially, approximately 2.3–31.6 per million in some datasets.
  • Peak frequency is at 12–16 years, approximately 11.2 per 100,000.
  • Males have about 3.8-fold greater risk than females.
  • Capitellar OCD incidence is approximately 6.0 per 100,000 overall—9.5 per 100,000 males and 2.6 per 100,000 females.
  • Ankle OCD incidence is approximately 4.6 per 100,000 among persons aged 6–19 years.
  • Across human series, females comprise roughly 20–40% of cases. (mccoy2013articularosteochondrosisa pages 9-11, konarski2024understandingosteochondritisdissecans pages 2-3)

Differences in case definitions, joint site, age window, imaging intensity, and athlete enrichment explain much of the heterogeneity. Population-wide prevalence of the broader “osteochondrosis” family cannot be calculated meaningfully by pooling all named juvenile disorders.

Inheritance

Most isolated disease is multifactorial/polygenic with incomplete penetrance and variable expressivity. Rare ACAN-associated familial OCD is autosomal dominant. Genetic anticipation, germline mosaicism, founder mutations, consanguinity effects, and general-population carrier frequencies are not established features. Strong family history or multifocal disease should prompt evaluation for skeletal dysplasia. (mccoy2013articularosteochondrosisa pages 5-7)

10. Diagnostics

Clinical assessment

Suspect OCD in a growing child or adolescent with persistent, activity-related joint pain, recurrent effusion, loss of motion, or mechanical catching/locking—particularly an athlete. Examination may show tenderness, swelling, reduced range of motion, gait alteration, or pain at terminal flexion/extension, but no finding is sufficiently sensitive to exclude disease. (konarski2024understandingosteochondritisdissecans pages 1-2, mccoy2013articularosteochondrosisa pages 2-4)

Imaging

  1. Plain radiography: first-line; use site-appropriate orthogonal and specialized views. It detects manifesta lesions, sclerosis, lucency, and fragments but can miss early disease.
  2. MRI: preferred for early detection and assessment of lesion size, cartilage integrity, marrow/subchondral changes, fluid undermining the fragment, and stability. MRI is more sensitive than radiography for early lesions.
  3. CT: useful for osseous architecture, fragments, cysts, and operative planning, but exposes the child to radiation.
  4. Ultrasound: limited adjunct for superficial lesions/effusion; not a definitive staging test.
  5. Arthroscopy: direct assessment and treatment; often the definitive stability assessment when imaging is equivocal. (konarski2024understandingosteochondritisdissecans pages 1-2, mccoy2013articularosteochondrosisa pages 2-4)

There is no diagnostic blood test, enzyme assay, circulating biomarker, liquid biopsy, or validated omics assay. Biopsy is not routinely required; histology, when available, shows retained/necrotic cartilage, failed ossification, clefts, fibrous repair, and variable subchondral remodeling.

Differential diagnosis

Differentials include acute osteochondral fracture, osteonecrosis, stress injury, normal ossification variants, infection, inflammatory arthritis, meniscal pathology, plica, loose body, chondral tumor, and site-specific conditions such as talar osteochondral lesions. Clinical context, lesion location, cartilage integrity, marrow reaction, and trauma history distinguish these.

Genetic diagnosis and screening

No population, newborn, or routine athlete-screening program is recommended. Contralateral-joint imaging may be considered when symptoms, multifocal disease, or familial disease suggest bilateral involvement. Genetic testing is phenotype-driven rather than routine.

11. Outcomes and prognosis

Osteochondrosis is generally not life-limiting; disease-specific mortality, reduced life expectancy, and survival rates are not meaningful endpoints. Morbidity arises from pain, sports restriction, stiffness, mechanical symptoms, surgery, and premature osteoarthritis.

Favorable prognostic factors include young skeletal age, open physes, early diagnosis, small stable lesion, intact cartilage, broad vascular attachment, and adherence to unloading. Unfavorable factors include physeal closure, large or atypically located lesions, cysts/sclerosis, instability, displacement, long symptom duration, and failed conservative care. Early detection is emphasized because fragmentation produces permanent cartilage injury and joint degeneration. (mccoy2013articularosteochondrosisa pages 9-11, konarski2024understandingosteochondritisdissecans pages 12-13)

Recovery is common for stable juvenile lesions, but exact healing rates depend heavily on joint, MRI definition, follow-up duration, and treatment. Unstable lesions are less likely to heal without fixation or restoration. No validated molecular prognostic biomarker exists.

12. Treatment

Treatment algorithm

Stable lesion, open physis, mild symptoms:

  • cessation of impact/throwing exposure;
  • protected weight bearing or immobilization when indicated;
  • analgesia/short-term NSAIDs for symptoms;
  • progressive physical therapy emphasizing range of motion, strength, and biomechanics;
  • serial clinical and radiographic/MRI assessment;
  • gradual return only after pain resolution and evidence of healing. The 2024 review recommends that return to sport occur only after symptoms resolve and at least six months have elapsed. (konarski2024understandingosteochondritisdissecans pages 1-2)

Persistent stable lesion: arthroscopic or image-guided retroarticular/retrograde or transarticular drilling to stimulate revascularization and healing.

Unstable but salvageable lesion: reduction, debridement of nonviable interface, drilling/bone grafting as needed, and fixation with screws, pins, or anchors.

Unsavable defect: fragment excision plus cartilage-restoration strategy selected by size, depth, site, and age—microfracture/marrow stimulation, osteochondral autograft or allograft, autologous chondrocyte implantation, scaffold-assisted repair, or combined bone/cartilage reconstruction. (konarski2024understandingosteochondritisdissecans pages 1-2, konarski2024understandingosteochondritisdissecans pages 12-13)

Evidence and clinical trials

The multicenter ROCK trial, NCT01754298, enrolled 91 participants and compared transarticular with retroarticular drilling for stable juvenile knee OCD. It was published in May 2023 in The American Journal of Sports Medicine, 51:1392–1402, DOI 10.1177/03635465231165290. The retrieved registry excerpt confirms the randomized comparison but did not expose arm-specific numerical outcomes; these should be abstracted from the full publication before entering response rates. (NCT01754298 chunk 2)

Other registered studies retrieved included platelet-rich plasma for juvenile knee OCD (NCT02397278, completed, 15 participants) and withdrawn demineralized bone matrix work (NCT01283737, 0 enrolled). These remain investigational and do not establish standard efficacy.

No approved disease-modifying drug, gene therapy, RNA therapy, immunotherapy, or genotype-guided pharmacotherapy exists. Cell/scaffold and orthobiologic procedures are cartilage-repair technologies rather than corrections of the initiating developmental vascular defect.

Suggested NCIt intervention mappings: Activity Modification, Physical Therapy, Immobilization, Arthroscopy, Internal Fixation Procedure, Bone Grafting, Microfracture, Osteochondral Autograft Transplantation, Osteochondral Allograft Transplantation, and Autologous Chondrocyte Implantation; codes should be resolved in the current NCIt release.

13. Prevention

Primary prevention

No intervention completely prevents multifactorial disease. Reasonable measures include healthy body weight, diversified age-appropriate activity, limits on repetitive throwing/jumping load, scheduled rest, progressive training, attention to alignment and technique, and avoidance of premature single-sport overuse. Evidence is risk-factor based rather than derived from definitive prevention trials. (konarski2024understandingosteochondritisdissecans pages 2-3)

Secondary prevention

Prompt evaluation of persistent activity-related pain or recurrent swelling, low threshold for MRI when radiographs are normal but suspicion remains, and early unloading of stable lesions may prevent progression to instability. There is no justified general-population imaging screen. (mccoy2013articularosteochondrosisa pages 2-4, konarski2024understandingosteochondritisdissecans pages 12-13)

Tertiary prevention

Protect healing lesions, monitor radiographic resolution, rehabilitate strength and motion, correct modifiable biomechanics, and delay return to high-impact sport until clinical and imaging recovery. The goal is prevention of fragmentation and secondary osteoarthritis. Genetic counseling is appropriate for ACAN-associated or skeletal-dysplasia-associated familial disease.

Vaccination, antimicrobial prophylaxis, environmental decontamination, and infectious-disease public-health measures are not applicable.

14. Other species and natural disease

Naturally occurring articular osteochondrosis is important in horses (Equus caballus, NCBI Taxon 9796), domestic pigs (Sus scrofa domesticus; parent taxon Sus scrofa, 9823), and dogs; analogous lesions also occur in production animals. Veterinary consequences include pain/lameness, reduced athletic performance, welfare problems, and economic loss.

Human, equine, and porcine disease share predilection sites, imaging and histologic features, focal cartilage avascular necrosis, failed endochondral ossification, and progression to cartilage fissure. Females are less frequently affected in humans and pigs, whereas equine disease shows no consistent sex difference. Estimated heritability in horses and pigs ranges from 0.14 to 0.52; reports indicate up to 70% of foals from affected sires may develop lesions and affected offspring may be approximately twice as likely as unaffected offspring. These values are population- and phenotype-dependent and should not be transferred to humans. (mccoy2013articularosteochondrosisa pages 7-8, mccoy2013articularosteochondrosisa pages 9-11, mccoy2013articularosteochondrosisa pages 5-7)

There is no transmission or zoonotic potential: cross-species similarity reflects conserved endochondral ossification, not infection. Breed-specific VBO identifiers and animal ortholog NCBI Gene IDs should be attached only after breed- and gene-specific database verification.

15. Model organisms and experimental systems

Natural and induced models

  • Pig and horse natural disease: best models of early lesion formation because large epiphyses and cartilage canals permit serial imaging and histopathology before clinical end-stage disease.
  • Surgical vascular-interruption models: transection of epiphyseal cartilage vessels reproduces focal ischemic chondronecrosis and delayed ossification, strongly supporting vascular failure as an upstream mechanism.
  • Large-animal drilling/cartilage-repair models: sheep, pigs, goats, and horses are used to test revascularization, fixation, scaffolds, and osteochondral repair.
  • Rodents: convenient for molecular manipulation but less faithful because epiphyseal scale, loading, and cartilage-canal biology differ.
  • In vitro chondrocytes, osteochondral explants, and organoids: useful for matrix, hypoxia, and mechanobiology, but cannot fully reproduce joint vascular transition and growth-related loading. (mccoy2013articularosteochondrosisa pages 7-8, mccoy2013articularosteochondrosisa pages 1-2)

Strengths and limitations

Natural large-animal disease reproduces the temporal sequence from latent vascular lesions to dissection and permits study of tissue unavailable from presymptomatic children. Limitations include species-specific growth rates, joint loading, predilection sites, husbandry, nutrition, and genetic architecture. Surgically induced vessel injury tests the ischemic mechanism but may over-simplify multifactorial human disease. (mccoy2013articularosteochondrosisa pages 9-11, mccoy2013articularosteochondrosisa pages 1-2)

Recent developments and expert interpretation

  1. Developmental-complex model strengthened (2023): serial human MRI demonstrated increasing lesion depth and heterogeneous changes at the articular–epiphyseal cartilage complex, favoring a dynamic developmental lesion rather than a single acute traumatic event. (edmonds2023evaluatingtheetiology pages 1-3)
  2. Comparative mechanism remains influential: vascular failure and chondronecrosis provide the most coherent upstream mechanism; repetitive load explains why lesions at mechanically vulnerable sites become symptomatic or unstable. (mccoy2013articularosteochondrosisa pages 7-8, mccoy2013articularosteochondrosisa pages 5-7)
  3. Treatment evidence improved: the 2023 multicenter randomized drilling trial directly compared two accepted approaches, although full numerical outcomes require extraction from the paper rather than the registry excerpt. (NCT01754298 chunk 2)
  4. Genetic phenotypic expansion (2024): reports of multiple OCD in COMP-associated multiple epiphyseal dysplasia reinforce that multifocal disease should trigger skeletal-dysplasia assessment.
  5. Clinical consensus (2024): age, physeal status, lesion stability, cartilage integrity, size, and location—not the label alone—should drive treatment. Stable juvenile lesions merit conservative care; unstable or displaced lesions require restoration of surface congruity and fixation when salvageable. (konarski2024understandingosteochondritisdissecans pages 1-2, konarski2024understandingosteochondritisdissecans pages 12-13)

Principal knowledge gaps

Major gaps include validated sporadic-risk loci, prospective gene–environment studies, standardized incidence estimates, biomarkers of instability, direct early-stage human histology, harmonized MRI criteria, long-term comparative effectiveness of cartilage-restoration methods, disease-specific quality-of-life data, and preventive trials in high-risk youth athletes. Evidence is particularly sparse for protective genetics, epigenomics, single-cell/spatial profiling, and genotype-guided therapy.

References

  1. (mccoy2013articularosteochondrosisa pages 7-8): A.M. McCoy, F. Toth, N.I. Dolvik, S. Ekman, J. Ellermann, K. Olstad, B. Ytrehus, and C.S. Carlson. Articular osteochondrosis: a comparison of naturally-occurring human and animal disease. Osteoarthritis and cartilage, 21 11:1638-47, Nov 2013. URL: https://doi.org/10.1016/j.joca.2013.08.011, doi:10.1016/j.joca.2013.08.011. This article has 161 citations and is from a domain leading peer-reviewed journal.

  2. (mccoy2013articularosteochondrosisa pages 2-4): A.M. McCoy, F. Toth, N.I. Dolvik, S. Ekman, J. Ellermann, K. Olstad, B. Ytrehus, and C.S. Carlson. Articular osteochondrosis: a comparison of naturally-occurring human and animal disease. Osteoarthritis and cartilage, 21 11:1638-47, Nov 2013. URL: https://doi.org/10.1016/j.joca.2013.08.011, doi:10.1016/j.joca.2013.08.011. This article has 161 citations and is from a domain leading peer-reviewed journal.

  3. (mccoy2013articularosteochondrosisa pages 1-2): A.M. McCoy, F. Toth, N.I. Dolvik, S. Ekman, J. Ellermann, K. Olstad, B. Ytrehus, and C.S. Carlson. Articular osteochondrosis: a comparison of naturally-occurring human and animal disease. Osteoarthritis and cartilage, 21 11:1638-47, Nov 2013. URL: https://doi.org/10.1016/j.joca.2013.08.011, doi:10.1016/j.joca.2013.08.011. This article has 161 citations and is from a domain leading peer-reviewed journal.

  4. (mccoy2013articularosteochondrosisa pages 5-7): A.M. McCoy, F. Toth, N.I. Dolvik, S. Ekman, J. Ellermann, K. Olstad, B. Ytrehus, and C.S. Carlson. Articular osteochondrosis: a comparison of naturally-occurring human and animal disease. Osteoarthritis and cartilage, 21 11:1638-47, Nov 2013. URL: https://doi.org/10.1016/j.joca.2013.08.011, doi:10.1016/j.joca.2013.08.011. This article has 161 citations and is from a domain leading peer-reviewed journal.

  5. (edmonds2023evaluatingtheetiology pages 1-3): Eric W. Edmonds, Marc Tompkins, James D. Bomar, and Andrew T. Pennock. Evaluating the etiology of osteochondritis dissecans of the knee: the role of the articular-epiphyseal cartilage complex. Journal of the Pediatric Orthopaedic Society of North America, 5(4):677, Nov 2023. URL: https://doi.org/10.55275/jposna-2023-677, doi:10.55275/jposna-2023-677. This article has 2 citations.

  6. (konarski2024understandingosteochondritisdissecans pages 1-2): Wojciech Konarski, Tomasz Poboży, Klaudia Konarska, Michał Derczyński, and Ireneusz Kotela. Understanding osteochondritis dissecans: a narrative review of the disease commonly affecting children and adolescents. Apr 2024. URL: https://doi.org/10.3390/children11040498, doi:10.3390/children11040498. This article has 15 citations.

  7. (konarski2024understandingosteochondritisdissecans pages 2-3): Wojciech Konarski, Tomasz Poboży, Klaudia Konarska, Michał Derczyński, and Ireneusz Kotela. Understanding osteochondritis dissecans: a narrative review of the disease commonly affecting children and adolescents. Apr 2024. URL: https://doi.org/10.3390/children11040498, doi:10.3390/children11040498. This article has 15 citations.

  8. (konarski2024understandingosteochondritisdissecans pages 12-13): Wojciech Konarski, Tomasz Poboży, Klaudia Konarska, Michał Derczyński, and Ireneusz Kotela. Understanding osteochondritis dissecans: a narrative review of the disease commonly affecting children and adolescents. Apr 2024. URL: https://doi.org/10.3390/children11040498, doi:10.3390/children11040498. This article has 15 citations.

  9. (mccoy2013articularosteochondrosisa pages 9-11): A.M. McCoy, F. Toth, N.I. Dolvik, S. Ekman, J. Ellermann, K. Olstad, B. Ytrehus, and C.S. Carlson. Articular osteochondrosis: a comparison of naturally-occurring human and animal disease. Osteoarthritis and cartilage, 21 11:1638-47, Nov 2013. URL: https://doi.org/10.1016/j.joca.2013.08.011, doi:10.1016/j.joca.2013.08.011. This article has 161 citations and is from a domain leading peer-reviewed journal.

  10. (NCT01754298 chunk 2): Benton Heyworth. Study of Two Surgical Drilling Techniques to Treat Juvenile Osteochondritis Dissecans of the Knee. Boston Children's Hospital. 2013. ClinicalTrials.gov Identifier: NCT01754298

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References checked 4
Resolved 4
Unresolved (possible confabulation) 0
Unverifiable 0
References weighed for topical relevance 4
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