[Anatomical study of the normal and degenerative articular surfaces on the first carpometacarpal joint].

Specimens of 138 first carpometacarpal joints (CMJ) from cadavers consisting of 59 females and 79 males and averaging 68.8 years of age were grossly evaluated and morphological measurements were performed. Macroscopic degeneration of cartilage surface was noted in the metacarpus of 97 hands and trapezium of 73 hands. 1) Morphological measurements of normal articular surfaces showed that metacarpal concave depth was shallower in the female than in the male and trapezial convex height was flatter in the female than in the male. 2) The degeneration of the articular surface was more often observed in the metacarpal joint than the trapezial joint, and the degree of degenerative changes on each articular surface was greater in the female than in the male. 3) In Grade I, the degeneration of the cartilage surface was observed both in the radial and ulnar facets of the trapezium and in the dorsal and palmar facets of the metacarpus. 4) As the degeneration progressed in both sexes, the trapezial concavity became deeper and its convexity became flatter than normal. On the other hand, the metacarpal concavity was flatter and its convexity was higher than normal. Moreover, these changes were more apparent in the female than in the male.