Complications Following Overlapping Orthopaedic Procedures at an Ambulatory Surgery Center

BACKGROUND Overlapping surgery occurs when a single surgeon is the primary surgeon for >1 patient in separate operating rooms simultaneously. The surgeon is present for the critical portions of each patient's operation although not present for the entirety of the case. While overlapping surgery has been widely utilized across surgical subspecialties, few large studies have compared the safety of overlapping and nonoverlapping surgery. METHODS In this retrospective cohort study, we reviewed the charts of patients who had undergone orthopaedic surgery at our ambulatory surgery center during the period of April 2009 and October 2015. A database of operations, including patient and surgical characteristics, was compiled. Complications had been identified and logged into the database by surgeons monthly over the study period. These monthly reports and case logs were reviewed retrospectively to identify complications. Propensity-score weighting and logistic regression models were used to determine the association between outcomes and overlapping surgery. RESULTS A total of 22,220 operations were included. Of these, 5,198 (23%) were overlapping, and 17,022 (77%) were nonoverlapping. The median duration of surgery overlap was 8 minutes (quartile 1 to quartile 3, 3 to 16 minutes); no operations were concurrent. After weighting, the only continuous variables that differed significantly between the groups were operative time (median, 57 compared with 56 minutes for the overlapping and the nonoverlapping group, respectively; p = 0.022), anesthesia time (median, 97 compared with 93 minutes; p < 0.001), and total tourniquet time (median, 26 compared with 22 minutes; p = 0.0093). Multivariable logistic regression models did not demonstrate an association between overlapping surgery and surgical site infection, noninfection surgical complications, hospitalization, or morbidity. CONCLUSIONS These data suggest that there is no association between briefly overlapping surgery and surgical site infection, noninfection surgical complications, hospitalization, and morbidity. When practiced in the manner described herein, overlapping orthopaedic surgery can be a safe practice in the ambulatory setting. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.