The temporal bone in osteopetrosis.

Abstract

OSTEOPETROSIS,also known as Albers-Schonberg disease, osteosclerosis, marble bones, and chalk bones, is a rare hereditary congenital and familial abnormality in bone development. The abnormality appears to be a failure of resorption of calcified cartilage and primitive bone.¹This necessarily interferes with the formation of the adult bone which normally replaces it. The abnormal bone development and the accompanying alterations in physiology give rise to a number of interesting clinical features. Radiographically there is a striking opacity of the bones and obliteration of the medullary cavity. The bones are hard since they contain large quantities of calcium salts but brittle since there is no organization of the unresorbed primitive bone to resist stress. The long bones break like chalk, transverse to their long axis²(Fig 1). A patient may have multiple fractures which heal producing a callus which has the same abnormal features as the original bone (Fig 2).