BMI and male gender are associated with increased operative time during total shoulder arthroplasty: an analysis of 16,568 patients

Introduction: Operative time has been shown to be a significant risk factor for short-term complications following total shoulder arthroplasty (TSA). Identifying TSA cases that require increased operative time may potentially lead to improved outcomes, yet there is a lack of previous research on specific risk factors associated with prolonged TSA operative time. The purpose of this study was to determine independent predictors for prolonged operative time following TSA. Methods: Adult patients undergoing primary TSA from 2006 to 2018 were identified in the National Surgical Quality Improvement Program database. Patients with sepsis, disseminated cancer, infection, or who underwent emergency surgery were excluded from our dataset. Prolonged operative time was defined as ≥ 150 minutes, or one standard deviation above the mean operative time of 109 minutes. Clinical characteristics assessed included age, sex, race, BMI, American Society of Anesthesiologists class, surgical setting (inpatient vs. outpatient), anesthesia type, preoperative albumin, and hematocrit. Comorbidities assessed included diabetes, smoking, dyspnea, functional status, chronic obstructive pulmonary disease, ascites, congestive heart failure, hypertension, renal failure, dialysis, steroid use, weight loss, bleeding disorder, and preoperative transfusion. Risk factors were assessed using bivariate and multivariate analysis. Results: Of 16,568 total patients undergoing TSA, 14.8% (2,453) had prolonged operative time. On bivariate analysis, younger age, male sex, nonwhite race, increased BMI, outpatient procedure, smoking status, dyspnea, steroid use, and bleeding disorder were significantly associated with prolonged operative time (all, P <.05). After controlling for confounding variables on multivariate analysis, increased BMI (OR 1.023; P =.045) and male gender (OR 1.647; P <.001) were found to be independent predictors of prolonged TSA operative time. Notably, age was not found to be an independent predictor of prolonged operative time (P >.05). Conclusion: Increased BMI and male gender were found to be predictive of prolonged TSA operative time. Since increased operative time has been shown to be associated with increased short-term postoperative complications, surgeons and perioperative teams should be aware of the potential for prolonged operative time in patients with these risk factors who undergo TSA. Level of Evidence: Level III; Retrospective Case-control Comparative Study