[Anatomical study of radiocarpal joint--degenerative change and morphometry]

The present investigator studied following degenerative changes of the articular cartilage of the radiocarpal joint: the ruptures of the scapholunate and the lunotriquetral interosseous ligaments (S-L lig., L-T lig.), the shape of the scaphoid and the lunate fossa of the distal radius. We studied 120 wrist joints from 74 cadaveric specimens (age 20-97, average age 68). The cartilaginous changes were correlated significantly with age (p < 0.01). The cartilaginous changes were most commonly found in the ulnar demarcation of the lunate, next commonly, in the radiodorsal demarcation of the scaphoid fossa, thirdly, in the radiodorsal demarcation of the scaphoid and finally, in the radial demarcation of the scaphoid fossa. Clearly, the cartilaginous changes in the ulnar demarcation of the lunate intensified proportionally as the ulnar variance increased (p < 0.05) and as the radial inclination decreased (p < 0.05). The S-L lig. and the L-T lig. ruptures increased as the age of the specimens increased. The cartilaginous changes of the interosseous ligament rupture group were stronger than those of the non ligament rupture group (p < 0.01). The concavity of the scaphoid fossa in the dorsovolar direction exhibited an S shaped curve, a convexity on the dorsal side and a concavity on the volar side. The other concavities exhibited a smooth concave curve. From these results, it was concluded that the stability of the wrist joint in extention and the cartilaginous changes of the radioscaphoid joint were due to the volar concavity of the scaphoid fossa of the radius.