Osteoid osteoma as a cause of knee pain in the young athlete

Knee problems are frequently seen in young athletes. It is important for the examining physician to be mindful of the complex differential diagnosis of knee pain in the adolescent, and not presume a traumatic origin of this pain. A case of osteoid osteoma of the distal medial condylar epiphysis of the femur in a 15-year-old athletic male, who presented with limitation of extension of the knee and medial joint pain and swelling, which could easily be misinterpreted as internal derangement, is discussed as an example of this problem.