Is negative ulnar variance a risk factor for Kienböck's disease? A meta-analysis.

Current treatment for Kienbock's disease using joint-leveling procedures is based on the hypothesis that the disease is caused by negative ulnar variance. The authors conducted a meta-analysis to evaluate this hypothesis, and assessed the quality of available published studies. They searched MEDLINE to collect literature that evaluated this association. Only 3 of 18 collected studies had sufficient data or study design to meet their inclusion criteria. A summary odds ratio (OR) calculated using a conservative random-effect method showed that the odds of Kienböck's disease was 3.10 times more likely for those with negative ulnar variance than those with positive or neutral ulnar variance, but this was not significant (95% confidence interval, 0.95-10.05; p = 0.06). The combined OR was unstable because of marked heterogeneity across the studies. This meta-analysis reveals that there is insufficient data to support a significant (p < 0.05) association between negative ulnar variance and Kienbock's disease.