Femoral Injury Over the Site of Spontaneous Regression of an Osteochondroma in a Teenage Athlete.

The spontaneous regression of an osteochondroma is extremely rare. We report a case of medial femoral condyle impaction fracture over the site of spontaneous regression of a pedunculated osteochondroma discovered on advanced imaging after an acute injury in a 16-year-old male American football athlete. Although spontaneous regression of an osteochondroma has been described, the case presented reveals questions regarding resultant architectural changes to the bone after resorption, leaving it prone to injury. This is the first case that describes increased injury risk potential at the site of osteochondral regression.