A review of the literature has revealed no complete classification of the neuropathic lesions of the bones and joints. Turney1has given the most detailed account of these abnormalities. Chipault,2Goodhart,3Albee4and others have mentioned the different conditions in which the lesions occur, but there is no agreement as to the etiologic grouping. Hence the following classification, based on etiologic factors, is presented. 1. Tabes Dorsalis 2. Syringomyelia 3. Following Lesions of the Peripheral Nerves (a) Injury (b) Peripheral neuritis (c) Leprosy 4. Following Lesions of the Spinal Cord (a) Injury (b) Congenital malformations (c) Tumors (d) Tuberculosis of the spine (e) Acute myelitis (f) Anterior poliomyelitis (g) Progressive (central) muscular atrophy (1) Aran-Duchenne type (2) Spastic type (amyotrophic lateral sclerosis) 5. Following Lesions of the Cerebrum (a) Dementia paralytica (b) Hemiplegia following cerebral hemorrhage. The first two groups, tabes dorsalis and syringomyelia, are so