Bone Changes in Leprosy: A Clinical and Roentgenologic Study of 505 Cases

Abstract

It is well known that there are two main types of leprosy, the lepromatous (formerly called cutaneous or nodular) and the neural, which differ widely in prognosis, pathology, and clinical manifestations. One of the important differences between the two types of the disease is the kind and extent of bone involvement. The usual and most remarkable bone changes are those of neurotrophic origin, which occur in the majority of neural cases and not in true lepromatous or nodular leprosy. Of an entirely different nature is the rarer and less conspicuous type of bone destruction seen in the lepromatous type of the disease. Most cases of neural and lepromatous leprosy sooner or later acquire lesions of the other type and thus become the mixed type, in which bone changes of both varieties occur. From a review of the literature it appears that little has been written on the subject in the last fifteen years. The two outstanding contributions within that period are those of Chamberlain, Wayson, and Garland (1931) and Murdock and Hutter (1932). Most of the bone changes seen by us have been described by other writers, but these have not reported such extensive bone destruction or made clear that certain bone changes correspond to certain types of the disease. Honeij (1917), for example, reported similar bone involvement in all types of leprosy, with bone absorption found as frequently in the nodular (lepromatous) type as in the neural. As long ago as 1911, Dyer and Hopkins, in Louisiana, were impressed by finding necrosis, atrophy, and absorption of digital bones confined practically exclusively to neural leprosy. This experience has continued unchanged at the National Leprosarium in the intercurrent years. Before reporting upon our findings it may be well to emphasize the fact that, since the usual bone changes occurring in leprosy are neurogenic, they are similar to those found in other neurotrophic diseases. For example, atrophic absorption of the phalanges has been found in Raynaud's disease, syringomyelia, tabes dorsalis, and chronic injuries of the spinal cord or of the peripheral nerves. Furthermore, other diseases may produce bone lesions similar to those of leprosy, as, for example, osteomyelitis, diabetic gangrene, gout, Buerger's disease, scleroderma, psoriasis, ainhum, frostbite, Boeck's sarcoid, tuberculosis, and syphilis. In addition, tabes may produce Charcot joints which occasionally involve the smaller articulations of the hands and feet with contractures which are indistinguishable from those of leprosy. The present study is based upon the observation of 505 patients with all types of leprosy at the National Leprosarium. Of this number 340 were males and 165 females, a proportion of over 2 to 1. The ages on admission to the leprosarium varied from four to seventy-six years. The majority of the patients were between twenty and forty-five years of age.