Neuroarthropathy of the foot in leprosy.

Among 449 patients with leprosy, 40 had clinical and radiographic evidence of neuroarthropathy in 50 feet. These changes were classified into four types according to the joints first involved by major lesions: ankle (25 feet), midtarsal (15 feet), tarsometatarsal (7 feet) and subtalar (3 feet). The progression of joint destruction was different in each type, but despite the severe destructive changes seen in radiographs, the patients had relatively few complaints. The muscles innervated by the peroneal nerve were severely paralysed in ankle and midtarsal types and it seems that, over a long term, repeated trauma and/or abnormal stress may lead to these types of neuroarthropathy. Neuropathy was less severe in the tarsometatarsal type of joint degeneration; the pathogenesis in this type seemed to be mainly direct trauma to the forefoot.