Epidemiology of Kienböck's disease in middle-aged and elderly Japanese women.

Little research has been done on the prevalence of Kienböck's disease, and there is no consensus on the relationship between Kienböck's disease and negative ulnar variance. The goal of this cross-sectional study was to determine the prevalence of Kienböck's disease in middle-aged and elderly Japanese women and to clarify the relationship between Kienböck's disease and negative ulnar variance. The authors analyzed plain radiographs of both hands in women 40 years and older residing in the community to investigate the prevalence of Kienböck's disease and the relationship between Kienböck's disease and negative ulnar variance. Kienböck's disease was seen in 7 of the 572 participants. In the group with Kienböck's disease, ulnar variance did not differ significantly between affected (0.3 mm; SD, 1.5) and unaffected (0.3 mm; SD, 1.0; P=.285) sides. No significant difference was seen in ulnar variance values between the affected side in the group with Kienböck's disease and the normal group (P=.118). The number or proportion of participants with negative ulnar variance did not differ significantly between the affected side in the group with Kienböck's disease (3 of 7) and the unaffected side in the group with Kienböck's disease (1 of 7; P=.237) and between the affected side in the group with Kienböck's disease and the normal group (111 of 504; P=.189) by chi-square test. The prevalence of Kienböck's disease was 1.2% in middle-aged and elderly Japanese women. Negative ulnar variance is not a contributing factor to Kienböck's disease.