Positive or Negative Ulnar Variance after Ulnar Shortening for Ulnar Impaction Syndrome: A Retrospective Study

BACKGROUND The goal of this study was to compare simple radiographic findings and clinical results according to residual ulnar variance following ulnar shortening for ulnar impaction syndrome. METHODS Forty-five cases of ulnar impaction syndrome, which were treated with ulnar shortening from 2005 to 2008, were studied retrospectively. Group I included 13 cases with positive residual variance after ulnar shortening and group II included 32 cases with negative variance after shortening. The presence of a lunate cystic lesion both preoperatively and at final follow-up and assessments of wrist function based on the modified Mayo wrist score, the disabilities of the arm, shoulder, and hand (DASH) score, as well as the Chun and Palmer score were evaluated. RESULTS A cystic lesion of the lunate was present in 4 cases preoperatively and the size decreased in 2 cases at final follow-up in group I, and in 10 and 5 cases, respectively, in group II. No statistical difference was observed between the groups. The modified Mayo wrist score, DASH score, as well as the Chun and Palmer score improved significantly in both groups. No significant differences were observed between the two groups in terms of the proportion of positive cystic lesions at final follow-up or the functional scores. CONCLUSIONS After ulnar shortening, the degree of radiological change in the cystic lunate lesions and clinical improvement did not differ significantly between the groups with unintended residual positive and negative variance after shortening.