Body mass index predicts perioperative complications following orthopaedic trauma surgery: an ACS-NSQIP analysis

Purpose: The impact of obesity on outcomes has been documented extensively in the elective orthopaedic literature, but little is known about the impact of obesity on outcomes following orthopaedic trauma surgery. Utilizing the ACS-NSQIP database, we sought to investigate the relationship between BMI and perioperative complications in orthopaedic trauma patients.

Methods: 53,219 orthopaedic trauma patients were identified using a CPT code search between 2005 and 2013 in the NSQIP database. Patient demographics, and perioperative complications (including minor, major, and total) were collected. Multivariate regression analysis was performed to control for baseline demographics and comorbidities.

Results: Compared with patients of normal weight, underweight patients had significantly greater odds of minor [OR 1.12, 95 % CI (1.0, 1.26), p = 0.04], major [OR 1.20, 95 % CI (1.1, 1.3), p = 0.0009], and total complications [OR 1.18, 95 % CI (1.1, 1.3), p = 0.0003]. Morbidly obese patients had significantly greater odds of major [OR 1.22, 95 % CI (1.0, 1.5), p = 0.023] and total complications [OR 1.18, 95 % CI (1.0, 1.4), p = 0.023] compared to normal weight patients. When wound-related complications were examined independently, obesity was associated with increased odds of superficial [OR 1.67, 95 % CI (1.3, 2.1), p < 0.0001] and deep wound infection [OR 1.52, 95 % CI (1.075, 2.144), p = 0.018], and morbid obesity was associated with increased odds of wound dehiscence [OR 2.29, 95 % CI (1.1, 4.9), p = 0.034] and deep infection [OR 2.51, 95 % CI (1.6, 3.9), p < 0.0001].

Conclusions: Morbidly obese patients have significantly greater odds of wound dehiscence, deep wound infection, major complications, and total complications compared to patients of normal weight. Additionally, BMI under 18.5 is associated with increased odds of minor, major, and total perioperative complications. Interventions aimed at decreasing complication rates should be targeted at these high-risk patient populations on both ends of the BMI spectrum.