Abstract
Multiple epiphyseal dysplasia is a genetically heterogeneous group of diseases causing altered enchondral ossification. It may affect the knee, among other joints, with variable clinical manifestations. In this report, we present a case of a young adult patient with multiple epiphyseal dysplasia, presenting recurrent catching and locking of the knee due to hyperplastic irregular cartilage. Although radiographs and magnetic resonance imaging of his knee were inconclusive with regard to the source of symptoms, arthroscopic examination revealed a flap of irregular and extensive hypertrophic cartilage of the medial femoral condyle that was causing catching during knee motions. This was treated by extensive arthroscopic resection of the hypertrophic cartilage with the knee held in a deep flexion position and symptoms resolved uneventfully. The case emphasizes the importance of a thorough arthroscopic examination when radiographs and magnetic resonance imaging may overlook the specific source for symptoms, and shows the potential for symptom resolution by arthroscopic intervention in these unusual circumstances.