Patterns of subchondral bone mineralization in the distal radioulnar joint

Our results show that in the sigmoid notch the load is transmitted through either the dorsal or palmar parts of the joint. In contrast the maximum bone density on the side of the ulna was found dorsally and centrally. We conclude that the ulna receives the maximum load in neutral position and supination, whereas because of the dorsopalmar translation of the ulnar head the radius may lead the ulna with either its palmar or dorsal borders during pronosupination. The ligamentous apparatus, the shape of the joint, and the ulna variance, however, may influence load transmission.