Intracapsular or para-articular chondromata usually occur at the knee where they are infrapatellar, extrasynovial, and deep to the patellar tendon. The presenting complaint is a mass and aching. Restricted motion is uncommon. There is no sex predilection. All patients were over twenty and were frequently in the fourth and fifth decade. The roentgenograms may be normal, show spotty areas of calcification, or demonstrate a lobulated oval osseous mass. The microscopic appearance varies with the stage of the lesion. Early, there is cartilage metaplasia and proliferation. This is followed by cartilage degeneration and calcification. With the ingrowth of vessels enchondral ossification occurs and may progress to complete bone replacement. The treatment is excision. Recurrence, as seen with synovial chondromatosis, and malignant degeneration have not been reported. These lesions must be differentiated from synovial chondromatosis and chondrosarcoma.
Copyright 1966 by The Journal of Bone and Joint Surgery, Incorporated