Femoral Osteochondritis Dissecans and Tibial Osteochondral Defect in an Adult Revealed by Bone SPECT/CT

A 46-year-old woman presented with persistent right knee pain and swelling six months after a fall. MRI initially showed a lateral meniscus tear, leading to meniscus repair and later meniscectomy, but symptoms persisted. Retrospective review of the MRI revealed edema in the tibial plateau and distal femoral condyle. Arthroscopic debridement demonstrated severe synovitis, marked cartilage loss of the lateral femoral condyle with a loose body, and tibial plateau cartilage damage. Bone SPECT/CT showed bony destruction, cleft formation, and focal tracer uptake in the distal femur and proximal tibia. Femoral osteochondritis dissecans and a tibial osteochondral defect were diagnosed based on arthroscopic and imaging findings.