Osteochondral Allograft Transplantation for a Large Focal Osteochondral Defect of the Lateral Femoral Condyle: Technical Note and Case Report.

Introduction: Focal osteochondral defects in young individuals pose a significant challenge, often leading to chronic knee pain, functional limitations, and early onset of osteoarthritis if untreated. Osteochondral allograft (OCA) transplantation can offer a promising solution for large osteochondral defects. The aim of the study is to present a surgical approach for managing a large focal osteochondral defect in the lateral femoral condyle of a young, active patient through OCA transplantation. Case Report: A 24-year-old male presented with atraumatic knee effusion, progressive pain, and impaired physical function. Imaging revealed a large osteochondral lesion in the lateral femoral condyle. After thorough pre-operative planning, including the creation of a 3D-printed model of the distal femur, the patient underwent lateral femoral condyle allograft transplantation. The procedure involved excision of the lesion, preparation of a size-matched OCA, and fixation with cannulated screws. Bone marrow aspirate concentrate was applied to enhance graft integration. Post-operative management included a progressive rehabilitation protocol with gradual knee flexion and weight-bearing. At 6 months postoperatively, the patient demonstrated significant clinical improvement with a Lysholm Knee Score of 89 and an International Knee Documentation Committee score of 87.4%. Follow-up imaging confirmed graft integrity and articular congruency. Conclusion: OCA transplantation is an effective surgical option for large osteochondral defects in the knee, providing satisfactory functional and clinical outcomes. This case highlights the importance of meticulous pre-operative planning, precise surgical technique, and structured post-operative rehabilitation in achieving successful results.