Combined Osteochondral Transplantation Versus Hybrid Transplantation and Mosaic Chondroplasty for Osteochondral Defects of the Femoral Condyles of Varying Size: A Cohort Study

AIM: To compare 12-month clinical and functional outcomes of combined osteochondral transplantation, hybrid osteochondral transplantation with mosaic chondroplasty, and mosaicplasty in patients with focal osteochondral defects of the femoral condyles, depending on defect area.METHODS: This cohort study with retrospective and prospective data collection was conducted at the trauma departments of City Clinical Hospital No. 1 named after N. I. Pirogov, Moscow City Health Department. It covered 136 operations performed in 2018–2025. Six mosaicplasty procedures from the retrospective part were performed before 2018, but their records contained preoperative questionnaire results. Inclusion criteria were age ≥18 years; a local post-traumatic or osteochondritis dissecans-related osteochondral defect of the femoral condyle or intercondylar groove; ICRS grade IV; bone component depth ≥7 mm; and defect area ≥2 cm² after debridement. Outcomes were assessed with the visual analog scale (VAS) and the LKSS, WOMAC, IKDC and KOOS scales before surgery and at 3, 6 and 12 months afterward. The primary outcome was KOOS-TOTAL at 12 months. Repair tissue was assessed with MOCART 2.0 at 12 months for defects 6 cm² in the combined and hybrid groups.RESULTS: The analysis included 142 patients: combined transplantation, 38 (26.8%); hybrid transplantation, 68 (47.9%); mosaicplasty, 36 (25.3%). At 12 months, combined transplantation outperformed mosaicplasty on all scales (KOOS-TOTAL 81.87 [77.29; 85.86] vs 74.34 [61.57; 80.51]; p 0.001). Compared with hybrid transplantation, it differed only in the KOOS Symptoms subscale (82.14 [71.41; 85.71] vs 71.40 [62.50; 78.60]; p = 0.003). The effect depended on defect area. For defects of 2.0–4.0 cm², the three techniques were comparable. For defects 6 cm², combined transplantation outperformed hybrid transplantation on 8 of 10 scales (KOOS-TOTAL 80.85 [78.34; 85.20] vs 70.69 [59.11; 75.13]; p 0.001) and on MOCART 2.0 (67.50 [60.00; 71.25] vs 55.00 [55.00; 67.50]; p = 0.043).CONCLUSION: Combined osteochondral transplantation may be the method of choice for defects 6 cm². For defects up to 4 cm², it offers no advantage over existing techniques. The conclusions are limited by the non-randomized choice of technique, small subgroups and the 12-month follow-up.