Ostosteoid osteoma of the knee : An unusual intra-articular localization

Osteoid osteoma is a common benign bone tumor, typically affecting long bones like the tibia and femur. Intra-articular forms, though rare, present diagnostic challenges. A 28-year-old man experienced persistent left knee pain unresponsive to medical treatment. A computed tomography (CT) scan identified a typical nidus at the femoral trochlea. Surgical excision was performed, confirming the diagnosis and leading to complete recovery with pain resolution. This case highlights the importance of CT for accurate diagnosis and the effectiveness of surgical treatment.