| Intervention/approach | Typical lesion characteristics/indications (size, depth, location, subchondral bone involvement) | Evidence type | Key recent findings/statistics with follow-up | Example 2023-2024 source (DOI/URL) | Example ClinicalTrials.gov NCT | Notes/limitations |
|---|---|---|---|---|---|---|
| Microfracture (marrow stimulation) | Common first-line reparative option for smaller full-thickness chondral/osteochondral knee defects; used for ICRS grade 3-4 lesions; less favorable when lesions are larger, patellofemoral/trochlear, weightbearing, degenerative, or when prior ipsilateral surgery has occurred (pqac-00000004, pqac-00000016, pqac-00000023) | Systematic review; active comparator in RCTs | Prognostic review found worse outcomes associated with higher age, larger lesion size, longer symptom duration, and prior ipsilateral surgery; favorable factors included nondegenerative mechanism, single lesion, and non-patellofemoral/non-weightbearing location. In Tseng 2024, microfracture improved IKDC by 27.51 ± 23.65 at 12 months in the control arm (pqac-00000004, pqac-00000016) | van Tuijn 2023, *Cartilage* 14:5-16. DOI: 10.1177/19476035221147680. https://doi.org/10.1177/19476035221147680 (pqac-00000004); Tseng 2024 DOI: 10.1186/s10195-024-00802-1 https://doi.org/10.1186/s10195-024-00802-1 (pqac-00000016) | NCT00719576; NCT03588975 (pqac-00000010, pqac-00000008) | Produces fibrocartilaginous rather than hyaline cartilage; concerns include subchondral sclerosis/cysts and potential impairment of later restorative options; durability concerns in larger/high-demand lesions (pqac-00000016, pqac-00000004) |
| Biphasic cartilage repair implant (BiCRI; autologous minced cartilage-based biphasic osteochondral construct) | Symptomatic femoral condyle/trochlear lesions; age <55 years; single lesion; lesion size <23 mm × 12.5 mm; ICRS grade 3-4 / Outerbridge 4 / OCD grade 3-4; designed for focal chondral or osteochondral defects with subchondral support component (pqac-00000017) | Prospective multicenter randomized non-inferiority trial | 92 randomized patients across 9 hospitals; 47 BiCRI and 45 microfracture completed follow-up. At 12 months, mean IKDC change was 25.56 ± 18.48 for BiCRI vs 27.51 ± 23.65 for microfracture; 95% CI for difference (BiCRI minus microfracture) −6.95, exceeding the non-inferiority margin of −12. Arthroscopy showed more fully regenerated cartilage in BiCRI group (pqac-00000016) | Tseng 2024, *J Orthop Traumatol* 25:62. DOI: 10.1186/s10195-024-00802-1. https://doi.org/10.1186/s10195-024-00802-1 (pqac-00000016) | NCT01477008 (pqac-00000016) | Short-term data only in provided snippet; comparator outcomes were similar clinically at 12 months despite better arthroscopic regeneration with BiCRI (pqac-00000016) |
| MACI / MACT (matrix-induced autologous chondrocyte implantation / matrix-assisted autologous chondrocyte transplantation) | Widely used for focal cartilage defects >2 cm²; large isolated lesions often >2.5 cm²; femorotibial and patellofemoral full-thickness ICRS grade 3-4 lesions; less suitable when marked subchondral edema is present; bone grafting may be needed if subchondral bone involvement >2 mm (pqac-00000021, pqac-00000022, pqac-00000023, pqac-00000007) | Long-term case series; prior RCT referenced in trial registry; ongoing randomized trial | Weishorn 2024: 103 patients, mean defect size 4.8 cm², 66% femorotibial; Kaplan-Meier survival free of revision 97.2% ± 1.6% at 10 years; MOCART 2.0 peaked at 12 months (80.2 ± 15.3) and remained stable at 96 months (76.1 ± 19.5; P=.142). BMI, MOCART 2.0, and number of prior surgeries associated with KOOS; only 30% with 2 prior surgeries and 20% with 3 prior surgeries reached PASS (pqac-00000021). Review snippet reports high satisfaction after MACI (98% at 5 years, 93% at 10 years) and >80% good-to-excellent infill at 5-10 years (pqac-00000007) | Weishorn 2024, *Am J Sports Med* 52:2782-2791. DOI: 10.1177/03635465241270152. https://doi.org/10.1177/03635465241270152 (pqac-00000021) | NCT00719576; NCT03588975; NCT05651997 (pqac-00000010, pqac-00000008, pqac-00000012) | Two-stage procedure; requires cell harvest/culture and rehab adherence; outcomes influenced by BMI and prior surgery burden; subchondral edema may steer treatment toward osteochondral grafting (pqac-00000021, pqac-00000007) |
| Augmented microfracture / AMIC / AMT (microfracture + collagen membrane / ECM scaffold) | Moderate-to-large lesions, including patellofemoral defects; used to stabilize marrow clot and concentrate mesenchymal cells; clinical trial entry targets ICRS grade 3-4 lesions sized 2.5-15 cm² (pqac-00000012, pqac-00000007, pqac-00000000) | Review; systematic comparison cited in review; planned randomized trial | Familiari 2024 PF review reported AMIC/aMFx effective for larger lesions (>2 cm²), with greater IKDC/Lysholm/Tegner improvement and lower VAS pain than microfracture and lower reported failure rates in reviewed cohorts. Cognetti 2024 review states a systematic comparison found AMIC had better Lysholm and IKDC scores and lower complication rates than ACI at ~40 months (pqac-00000000, pqac-00000007) | Cognetti 2024, *Bioengineering* 11:246. DOI: 10.3390/bioengineering11030246. https://doi.org/10.3390/bioengineering11030246 (pqac-00000007) | NCT05651997 (pqac-00000012) | Evidence in provided snippets is mostly review-level/heterogeneous; not all series are randomized; intended to improve on standard marrow stimulation rather than replace restorative options in all settings (pqac-00000000, pqac-00000007) |
| Osteochondral autograft transfer (OAT/OATS, mosaicplasty) | Best suited to smaller focal osteochondral lesions, especially when osteochondral unit restoration is needed; PF review favored for lesions <2 cm²; useful when subchondral bone is involved (pqac-00000000, pqac-00000007) | Review; RCT evidence cited in review; systematic review data cited in review | Cognetti 2024 review states OAT had RCT evidence showing superior return-to-sport vs marrow stimulation at mean 37 months; pooled long-term success in systematic review was 72%. PF review favored OAT for smaller lesions (<2 cm²) (pqac-00000007, pqac-00000000) | Cognetti 2024, *Bioengineering* 11:246. DOI: 10.3390/bioengineering11030246. https://doi.org/10.3390/bioengineering11030246 (pqac-00000007) | — | Donor-site morbidity and limited graft volume are not detailed in the provided snippets, but lesion size limits applicability; generally used for smaller defects (pqac-00000000, pqac-00000007) |
| Osteochondral allograft transplantation (OCA/OCAT; with or without meniscus allograft transplantation) | Large/deep defects, revision cases, or lesions with significant subchondral bone disease/edema; indicated in symptomatic articular cartilage lesions ≥2 cm² and/or meniscal deficiency in registry study; often used for femoral condyle, trochlea, patella, or plateau lesions (pqac-00000023, pqac-00000020, pqac-00000024) | Prospective registry/case series; review | Richards 2024 OCAT+MAT registry: 23 patients, mean age 37.1 years, mean BMI 28, mean follow-up 51 months; initial success 78%, overall success 83% after successful revision OCAT; all failures in medial compartment; older age (42.2 vs 32.1 years, P=.046) and rehab nonadherence (OR 14, P=.033) were risk factors; all PROMs improved significantly and achieved MCID (pqac-00000020) | Richards 2024, *Orthop J Sports Med* 12(9). DOI: 10.1177/23259671241256619. https://doi.org/10.1177/23259671241256619 (pqac-00000020) | — | Evidence snippet specifically concerns OCAT + concomitant MAT rather than isolated OCA; outcomes depend on patient selection and strict rehabilitation adherence (pqac-00000020) |
| Allogeneic umbilical cord blood-derived MSC implantation (UCB-MSC + sodium hyaluronate) | Older adults with larger focal lesions: age 40-70 years; medial femoral condyle; Outerbridge grade 3-4; defect size >4 cm²; intact ligaments; excluded if realignment osteotomy, meniscal deficiency, instability, or full-thickness lateral/PF lesion needed treatment (pqac-00000018, pqac-00000019) | Case series | 85 patients; mean age 56.8 ± 6.1 years; mean defect size 6.7 ± 2.0 cm². IKDC, VAS, and WOMAC improved significantly through short-term follow-up (1, 2, 3 years; P<.001). MRI at 1 year: hypertrophy grade 1 in 28, grade 2 in 41, grade 3 in 16; hypertrophy did not correlate with PROs (pqac-00000018) | Song 2023, *Orthop J Sports Med* 11(4). DOI: 10.1177/23259671231158391. https://doi.org/10.1177/23259671231158391 (pqac-00000018) | — | Non-randomized; all patients demonstrated repair tissue hypertrophy; evidence is short-term and focused on medial femoral condyle lesions in middle-aged/older adults (pqac-00000018) |
| Nonoperative/supportive care (PT, activity modification, weight loss, bracing, injections) | Usually first step for symptomatic focal lesions or as bridge to surgery; particularly relevant when symptoms are mild or surgery must be delayed; not curative for established focal defects (pqac-00000025, pqac-00000006) | Review | Dedicated PT/rehab, activity modification/rest, and counseling on weight loss/tobacco use are recommended first-line. Review notes weight loss over 48 months was associated with lower MRI progression of cartilage degeneration; injections (HA, corticosteroids, PRP/biologics) may reduce symptoms but there is no evidence they reverse existing chondral damage (pqac-00000025) | Cognetti 2024, *Bioengineering* 11:246. DOI: 10.3390/bioengineering11030246. https://doi.org/10.3390/bioengineering11030246 (pqac-00000025) | — | Symptom-relieving rather than restorative; biologic injections remain debated and high-level evidence for focal defect repair is lacking in provided snippets (pqac-00000025) |
| Emerging tissue-engineered osteochondral graft (EB-OC) | Up to two symptomatic full-thickness femoral condyle/trochlear defects, each 0.75-3 cm², ICRS grade 3-4, BMI ≤35, bone loss limits apply; comparator is abrasion chondroplasty (pqac-00000014, pqac-00000015) | First-in-human randomized phase I/IIb trial (planned) | Trial will assess safety and efficacy over 24 months; secondary endpoints include KOOS, IKDC, AMADEUS, MOCART, and CT-based integration. Product is a living tissue-engineered cartilage layer attached to a bone scaffold derived from allogeneic bone marrow MSCs (pqac-00000014) | ClinicalTrials.gov entry updated 2025-03-26 (study planned from 2026): https://clinicaltrials.gov/study/NCT06895889 (pqac-00000014) | NCT06895889 (pqac-00000014) | Investigational only; no clinical outcomes yet in provided evidence; comparator is abrasion chondroplasty, not current restorative standard in many settings (pqac-00000014) |


*Table: This table summarizes key operative and nonoperative interventions for focal chondral/osteochondral defects of the knee, emphasizing lesion selection, evidence type, recent outcomes, and active trial examples. It is designed as a quick-reference artifact for comparing current treatment strategies and evidence strength.*