IN 1868 Charcot1 described 4 cases of tabes dorsalis in which, without obvious trauma, joints of the lower extremities became involved in firm, painless swelling, the surfaces undergoing changes which produced false positions and luxations of the bones. Similar changes were described in syringomyelia by Schultze and Kahler,2 and according to Schlesinger3 the condition may develop in 30 to 40 per cent of patients with this lesion of the spinal cord. Whereas in tabes the lower extremities are more often affected, in syringomyelia the upper extremities are favored. Such arthropathies following injury of the peripheral nerves were first reported by Packard,4 who described a case in which a sciatic nerve was compressed by tumor. Other inciting causes which have been found are injury of the brachial plexus and spina bifida.
The disease usually begins in the cartilage and the zone of calcification between the cartilage