Arthroscopic resection of an intra-articular osteochondroma of the knee in the patient with multiple osteochondromatosis.

Osteochondroma is usually located outside of the joint and is asymptomatic. We have witnessed the symptoms of intra-articular osteochondroma of the knee joint and resected it arthroscopically. A 54-year-old woman with multiple osteochondromatosis presented with pain and a click on the right knee. Click was palpable and audible at the lateral aspect of the patellofemoral joint. Arthroscopy revealed that osteochondroma in the anterolateral site of the distal femur impinged the lateral edge of the lateral facets of the patella and the inflammatory change of the lateral capsule of the patellofemoral joint. Arthroscopic resection of this osteochondroma completely eliminated the symptoms. To our knowledge, this is the first report of arthroscopic resection of an osteochondroma in the intra-articular joint.