Abstract
1. Hereditary multiple exostosis has been studied in fifty-six patients and their relatives. In most cases previous records were available and the progress of the disease could be traced over many years.
2. The characteristic lesions are described and the complications encountered in the present series of cases are noted. The disease is inherited in approximately two-thirds of the cases and invariably produces detectable lesions in the heterozygote.
3. The cartilage-capped exostoses are confined to the endochondral skeleton where their incidence is closely related to the growth potential of the sites involved.
4. An attempt has been made to explain the curious distribution of the exostoses, and the likely theories of the pathogenesis of the disease are discussed.
