Osteopetrosis: a scanning electron microscopic study.

Scanning electron microscopic investigation was conducted with bone in a case of osteopetrosis by comparing it with normal cortical bone. The fractured surface of the osteopetrotic bone was devoid of the orderly constructed lamellar haversian system seen in normal bone. It was occupied by a massive smooth cartilaginous matrix containing scattered rough areas of abnormal ossification. Tortuous channels were randomly distributed and corresponded to the abortive marrow spaces. The presence of many irregular fracture lines reflected the fragility of the bone. The findings support the concept of defective remodeling in the pathogenesis of osteopetrosis and provide a further explanation for the abnormal fragility of bone in osteopetrosis.