Roentgen features of skeletal involvement in small pox.

Abstract

Summary Early and late roentgen features of skeletal manifestations of small pox are presented, based on a study of 20 such cases. Early roentgen features are soft tissue swelling of joints, periostitis of all bones at the joint, and metaphyseal osteoporosis and destruction. Inadvanced cases there is disorganisation of involved joints, fragmentation of epiphyses and excavation of articular surfaces. In the absence of secondary infection, the periostitis either is organised and merged with the old or resorbed leaving a normal diaphyseal contour with some sclerosis. In the presence of sinuses and secondary infection, roentgen features of frank pyogenic osteomyelitis appear. One case of spondylitis, a new feature, due to small pox is reported. Late manifestations of small pox are ankylosis, subluxation, dislocation, shortening and deformity of long and short tubular bones, flared metaphyses and precocious osteoarthritis. Differentiation of pseudo-achondroplastic changes of small pox and short metacarpals from achondroplasia and pseudo-pseudo-hypopara-thyroidism respectively is discussed. Differential diagnosis from bacterial osteomyelitis is also discussed. In all patients with deformities of limbs, a history of small pox should be enquired into.