Force distribution through the wrist joint in patients with different stages of Kienböck's disease: using computed tomography osteoabsorptiometry.

The pattern of subchondral bone density has been considered to reflect the stress distribution that occurs under physiologic loading conditions. To determine the force distribution through the wrist joint with Kienböck's disease in living subjects, we applied a computed tomography osteoabsorptiometry and investigated the subchondral bone density pattern across the radio-carpal joint of 6 normal subjects and 10 patients suffering from Kienböck's disease (Lichtman's stage IIIA, 5 patients; stage IIIB, 5 patients). A single density maximum was found in each scaphoid and lunate fossa in all normal subjects. Among the subjects with Kienböck's disease, the current analysis demonstrated that the density maximum area significantly increased in the scaphoid fossa and decreased in the lunate fossa from stage IIIA to IIIB group. These findings indicate that the load is shifted away from the lunate to the scaphoid with the progression of Kienböck's disease in living subjects.