Autologous Osteochondral Transplantation in Large Osteochondral Defects—A Follow-Up of 52 Patients After Knee Joint Resurfacing

<b>Background:</b> Autologous osteochondral transplantation (AOT)-the transfer of hyaline cartilage with its underlying subchondral bone-is well established for focal osteochondral lesions, yet evidence for larger (>200 mm²) defects is limited. We assessed clinical and functional outcomes of AOT in patients with osteochondral knee lesions exceeding 200 mm². <b>Methods:</b> In this retrospective cohort study, 52 patients underwent AOT for full-thickness osteochondral defects of the femoral condyles or patellofemoral joint. All lesions were ≥200 mm² and treated with a standardized press-fit technique using one to four overlapping cylindrical grafts. Pain and knee function were evaluated preoperatively and at 3, 6, and 12 months postoperatively with the Visual Analogue Scale (VAS), Tegner-Lysholm Knee Score (TLKS), and Knee Society Score (KSS). <b>Results:</b> Mean defect size was 224.4 ± 84.5 mm². The VAS improved from 6.32 ± 1.1 preoperatively to 0.72 ± 0.6 at 12 months (<i>p</i> < 0.001). The TLKS rose from 58.6 ± 11.4 to 95.0 ± 6.8 and the KSS from 63.8 ± 12.2 to 97.4 ± 4.9 during the same period (both <i>p</i> < 0.001). Most gains occurred within the first 3-6 months and were sustained at 12 months. No major surgical complications were observed, and outcomes were unaffected by age, sex, or graft number/size. <b>Conclusions:</b> AOT is a safe, effective option for large osteochondral knee defects (>200 mm²), offering rapid, durable pain relief and excellent functional recovery while preserving native joint structures. Accurate donor site reconstruction and precise graft placement in the weight-bearing zone appear critical for optimal results. Longer-term prospective studies are needed to confirm durability and refine patient-selection criteria.