resorptive changes, depending on stresses peculiar to the joint involved and location within the joint (4,7). Endochondral bone formation may occur but requires a blood supply and is confined to loose bodies with a pedicle or to free loose bodies that have regained a synovial attachment (4,9).In the late stages of the disease, the generalized synovial reaction reverts to normal. Secondary osteoarthritis results from the presence of loose bodies within the joint in chronic cases (6, 8, 9). This may cause localized secondary synovial chondromatosis, as well as osteochondritic loose bodies formed by detached osteophytes. Therefore, in older cases of long duration only a presumptive diagnosis of primary synovial chondromatosis can be made based on the history and the number and character of the loose bodies.Synovial chondrosarcoma has to be considered in the differential diagnosis of synovial chondromatosis since both lesions may exhibit synovial calcification and atypical multinucleated cartilage cells (9, 13, and 16). The diagnosis of chondrosarcoma is established on the basis of a large, lobulated synovial lesion with extra-articular invasion and histological sections which exhibit numerous multinucleated cartilage cells having bizarre hyperchromatic nuclei. Secondary synovial chondromas, attached or free, which occur in association with traumatic internal derangement and osteoarthritis, are distinguished by the existence of primary joint disease and localized synovial reaction. Traumatic joint surface separations and detached chondro-osteophytes represent true osteochondritic loose bodies and are readily differentiated. Loose bodies resulting from traumatic disruption of epiphyses, joint fibrocartilage or articular cartilage exhibit the gross and histological features of the normal joint structures involved. Chondro-osteophytes, usually no more than two or three in number, are often large and are found in a diseased or arthritic joint.Microscopically they exhibit a periphery of fibrocartilage with underlying cancellous dead bone and a zone of calcification. The classic loose body (osteochondritis dissecans) is most often single and involves an otherwise normal joint. It is distinguished microscopically by a periphery of articular cartilage, fibrotic reparative reaction, and underlying necrotic bone.A close differential of this condition would be melorrheostosis with soft tissue involvement. This condition demonstrates an inner undulating margin encroaching into the medullary cavity with a linear track pattern. Typically there is a wavy cortical hyperostosis in the bone which simulates molten wax flowing down the side of a candle (17, 18). This may have an intra articular extension with or without joint effusion. Heterotopic bone formation and soft tissue calcification can rarely occur. Pathological examination shows variable degree of marrow fibrosis with irregular mixed areas of lamellar and woven bone. This was not seen in our patient.Osteopoikilosis is differentiated from melorrheostosis by symmetrical involvement, a normal scintigraphy, absence of soft tissue involvement, and no related symptomatology. Other differential diagnoses to consider would include myositis ossificans and calcified hematoma. Other sclerosing bone dysplasias encompass Jaffe-Lichenstein disease which is a polyostotic fibrous dysplasia, which shows more frequent osteolytic areas and related histopathological changes.The only other case report describing this association depicted multiple loose bodies in the hip joint and small spherical areas of increased density in keeping with generalized osteopoikilosis. (15). The authors speculated that chondromatosis is