Presentation
Knee pain for months.
Patient Data
Small knee joint effusion.
Osteochondral lesion of the inferior aspect of the medial patellar facet with a full-thickness chondral defect, subchondral plate irregularity and marrow edema throughout the medial aspect of the patella. Femoral trochlea is normal.
Normal menisci, collateral ligaments and cruciate ligaments.
Case Discussion
The patella is a less common site for osteochondritis dissecans (OCD) of the knee. Perhaps, the only potential differential diagnosis is a dorsal defect of the patella, which occur in the superolateral aspect of the patella, whereas OCD more commonly occurs in the inferomedial aspect of the patella with abnormal articular cartilage.