A case of localized form of dysplasia epiphysealis hemimelica in an adult with fracture of the osteochondroma
Dysplasia epiphysealis hemimelica
A 39 years old male presented with history of on and off right ankle pain for the past 3 months. It was not associated with fever. No history of trauma was noted. Patient was non diabetic, non hypertensive and no known history of inflammatory/ infective joint disease was noted.
Non contrast CT right ankle joint showed a bony protrusion arising from the distal aspect of the tibia. It was projected anteriorly and was in continuity with the parent bone. No associated soft tissue component was noted. No periosteal reaction was seen. No evidence of degenerative change was noted in the ankle joint. Irregular linear discontinuity suggestive of fracture was noted in the bony outgrowth at the site of attachment with the tibia. No loose bodies were noted in the joint space.
Dysplasia epiphysealis hemimelica is a rare congenital disorder characterized by the development of osteochondromas from the epiphysis. Also known as Trevor disease, it is more common in young children and has a male predilection. Adult cases of dysplasia epiphysealis hemimelica is relatively rare, however, adult cases have been reported before. In this condition, there is asymmetric cartilage overgrowth leading to the limb deformity. Patient usually present with a painful joint, lump or swelling. This condition predominantly affects the lower extremities. Three forms have been described in the literature: classic form (characteristic hemimelic distribution with single lower extremity involvement), localized form (single bone affected) and generalized form (whole limb affected). Imaging studies help in establishing the diagnosis and in detecting the complications associated with the disease. X-ray and CT show bony outgrowth from the epiphysis that is in continuity with the parent bone. MRI can help in evaluating the underlying ligaments and the cartilage. Common complications associated with it are fragmentation and detachment leading to intra articular loose body formation, chronic tendonitis and tenosynovitis due to irritation by the outgrowth and secondary degeneration of the joint. Treatment depends upon the severity of the symptoms. Asymptomatic cases can be followed up conservatively, however, in symptomatic cases surgical excision with preservation of joint needs to be undertaken.
Although more common in the young population, dysplasia eiphysealis hemimelica can also occur in adults. It can be the cause of chronic joint pain in affected individuals. Proper imaging evaluation can not only help in the diagnosis of the condition but also in evaluating the complications associated with it.