Anatomic Variations in Radial and Ulnar Lengths Ulnar Variance of the Normal Wrists and Kienbock's Disease in Korean

The traumatic etiology is accepted generally. Some author believes that a relative discrepancy in the distal extent of the radius and ulnar plays a major role in the genesis of avascular necrosis of the lunate bone, the other belives little bearing. Over the years, the author have collected the ten cases of Kienbocks disease in Korean and then was interested the anatomic variations in radial and ulnar lengths in the wrist. The author measured the ulnar variance in 296 random normal Korean adults and in ten cases of Kienbocks disease to find out whether Hultens theory was borne out or whether Chan and Huang's observations were futher supported. The results obtained are as follows: 1. Mean ulnar variance in 296 normal Korean adults was +0.692 mm and +0.593 mm, +0.884 mm in male and female respectively. 2. In 296 normal Korean adults, the positive ulnar variance was 50.3%, in 29.7% neutral variance and in 20.0% negative ulnar variance. In ten cases of the patients with Kienbocks disease, the positive ulnar variance revealed in 4 cases, the neutral variance in 4 cases and the negative ulnar variance in 2 cases. 3. The relationship associated between the negative ulnar variance and Kienbock's disease reveals no statistical significance in Koreans.