Risk Factors for Complications in Ulnar Shortening Osteotomies: A Multicenter Retrospective Review

Abstract

Ulnar shortening osteotomy (USO) is commonly performed to alleviate pathologies causing ulnar-sided wrist pain. Surgical complications include nonunion and hardware removal, with rates up to 18% and 45%, respectively. The primary objective of the study was to report the overall complication rate of USO. The secondary objective was to identify risk factors for complications. A retrospective multicenter cohort review was undertaken, including six Canadian cities over a 6-year period (January 2013-December 2018). Chart review was used to collect demographic data, surgical technique, implant used, and postoperative complications. Descriptive statistics of demographics and operative characteristics, including plate positioning, type of osteotomy, plate type, and ulnar variance (mm), were analyzed. Univariate analyses were used to select predictor variables for nonunion and hardware removal. These predictor variables were then entered into an adjusted multivariable logistic regression model. A total of 361 USOs were performed. Mean age was 46 ± 16 years (60.7% men). The overall complication rate was 37.1%, hardware removal rate was 29.6%, and nonunion rate was 9.4%. There was a workers' compensation claim associated with 21.6% of all complications, and it was a risk factor for both hardware removal (odds ratio [OR]= 3.81) and nonunion (OR= 2.88). Neither smoking nor diabetes was associated with complication rates. Seventy percent of plates were placed volarly, 25.5% dorsally, and 3.9% directly ulnar. Osteotomies were oblique in 83.7% of cases and transverse in 15.5%. Adjusted multivariate regression analysis revealed that younger age (OR= 0.98) was a risk factor for hardware removal and male sex (OR= 0.40) was a risk factor for nonunion. A surgical factor associated with hardware removal was direct ulnar plate placement (OR= 9.93). No surgical factors were associated with nonunions. There are substantial rates of complications with USOs. Direct ulnar plate placement should be avoided. Patients should be thoroughly counseled on the risks of complications prior to proceeding with USO. Therapeutic IV.