The impact of obesity on complications of elbow, forearm, and hand surgeries.

PURPOSE: To compare the rates of postoperative complications in obese and nonobese patients following elbow, forearm, and hand surgeries.

METHODS: This case-control study examined 436 patients whose body mass index (BMI) was over 35 and who underwent hand, wrist, forearm, or elbow surgery between 2009 and 2013. Controls were patients (n = 433) with a BMI less than 30 who had similar surgeries over the same period, and who were frequency-matched by type of surgery (ie, bony, soft tissue, or nerve), age, and sex. Postoperative complications were defined as infection requiring antibiotic or reoperation, delayed incision healing, nerve dysfunction, wound dehiscence, hematoma, and other reoperation. Medical comorbidities (e.g., hypertension, diabetes, stroke, vascular disease, kidney disease, and liver disease) were recorded. Chi-square analyses were performed to explore the association between obesity and postoperative complications. Similar analyses were performed stratified by surgery type and BMI classification. Logisticregression modeling was performed to identify predictors of postoperative complications accounting for surgery type, BMI, the presence of comorbidities, patient age, and patient sex. This same model was also run separately for case and control patients.

RESULTS: The overall complication rate was 8.7% with similar rates between obese and nonobese patients (8.5% vs. 9.0%). Bony procedures resulted in the greatest risk of complication in both groups (15% each group). Multivariate analysis confirmed surgery type as the only significant predictor of complications for nonobese patients. However, among obese patients, both bony surgery and increasing BMI were associated with greater complication rates.

CONCLUSIONS: Not all obese patients appear to be at any higher risk for complications after elbow, forearm, and hand surgery compared with nonobese patients. However, there appears to be a dose-dependent effect of BMI among obese patients such that increasing obesity heightens the risk of complications, especially for those with a BMI greater than 45.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.