This study was conducted to further characterize the nature of leprosy-related bone alterations, to develop a hypothesis of their pathophysiology, and to define the impact of treatment on bone damage. Radiographs of 60 patients under care at the Carville, Louisiana leprosy hospital were compared with 50 from the early (before availability of effective treatment) part of this century and with 27 from the Toronto (Ontario, Canada) leprosy clinic.Two-thirds of lesions were so severe that distal digital tufts had been lost to whittling, resorption, or fragmentation. Fifty percent were felt to be pathognomonic for the changes of leprosy.Resorption, fragmentation, and malaligned fractures are highly suggestive of leprosy, while diaphyseal whittling appears specific when medullary sclerosis or wavy diaphyseal borders are present. Medicinal intervention appeared to be of limited benefit for bone damage; perhaps greater attention to joint/bone protection (as recommended in diabetes management) will prove helpful. Environmental adjustment to minimize injury risk and daily limb examination for injury are recommended.