Unstable osteochondral fragment of the lateral femoral condyle containing the popliteus tendon origin. Report of three cases.

We report a series of three cases of unusual locations of chronic osteochondral fragments arising from the posterolateral aspect of the lateral femoral condyle, presenting acutely in young adults, in which the unstable fragment contained the origin of the popliteus tendon, with MRI and arthroscopic correlation. Although atypical, we hypothesize that these cases represent adult osteochondritis dissecans with extension to a popliteus tendon origin. Preoperative diagnosis of popliteus tendon involvement may influence clinical management in patients with an unstable osteochondral fragment in this location.