Effect of operative time in outcomes following surgical fixation of hip fractures: a multivariable regression analysis of 35,710 patients

Background: Prolonged operative time is a risk factor for increased morbidity and mortality after open reduction and internal fixation (ORIF) of hip fractures. However, the quantitative nature of such association, including graduated risk levels, has yet to be described. This study outlines the graduated associations between operative time and (1) healthcare utilisation, and (2) 30-day complications after ORIF of hip fractures. Methods: The National Surgical Quality Improvement Program (NSQIP) database was queried (January 2016–December 2019) for all patients who underwent ORIF of hip fractures (n = 35,710). Demographics, operative time, fracture type, and comorbidities were recorded. Outcomes included healthcare utilisation (e.g., prolonged length of stay [LOS>2 days], discharge disposition, 30-day readmission, and reoperation), inability to weight-bear (ITWB) on postoperative day-1 (POD-1), and any 30-day complication. Adjusted multivariate regression models evaluated associations between operative time and measured outcomes. Results: Operative time <40 minutes was associated with lower odds of prolonged LOS (odds ratio [OR] 0.77), non-home discharge (OR 0.85), 30-day readmission (OR 0.85), and reoperation (OR 0.72). Operative time ⩾80 minutes was associated with higher odds of ITWB on POD-1 (OR 1.17). Operative time ⩾200 minutes was associated with higher odds of deep infection (OR 7.5) and wound complications (OR 3.2). The odds of blood transfusions were higher in cases ⩾60 minutes (OR1.3) and 5-fold in cases ⩾200 minutes (OR 5.4). The odds of venous thromboembolic complications were highest in the ⩾200-minute operative time category (OR 2.5). Operative time was not associated with mechanical ventilation, pneumonia, delirium, sepsis, urinary tract infection, or 30-day mortality. Discussion: Increasing operative time is associated with a progressive increase in the odds of adverse outcomes following hip fracture ORIF. While a direct cause-effect relationship cannot be established, an operative time of <60 minutes could be protective. Perioperative interventions that shorten operative time without compromising fracture reduction or fixation should be considered.