TOPOGRAPHY OF THE OSTEOARTHRITIC THUMB CARPOMETACARPAL JOINT AND ITS VARIATIONS WITH REGARD TO GENDER, AGE, SITE, AND OSTEOARTHRITIC STAGE

The articular topography of 46 osteoarthritic thumb carpometacarpal jo ints was quantitatively analyzed, as well as variations with regard to gender, age, site, and anatomic osteoarthritic stage. It was found th at for osteoarthritic thumb carpometacarpal joints, (1) the opposing a rticular surfaces of elder and severely degenerated joints are more co ngruent than those of middle-aged and minimally or moderately degenera ted joints, although the articular contact area is not significantly d ifferent when accounting for thinning of the cartilage layer with age or disease; (2) significant changes in joint topography due to osteoar thritis only occur in severely degenerated joints; (3) joints in women are less congruent, have smaller contact areas, and are likely to exp erience higher contact stresses than joints in men for similar activit ies of daily living that involve similar joint loads; and (4) osteoart hritic changes are less severe on the dorsoulnar aspect of the trapezi um and the dorsal aspect of the metacarpal, which are known to be low load-bearing regions. (C) 1998 by the American Society for Surgery of the Hand.