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. O verlapping 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. Although overlapping surgery has only recently been recognized by the greater public, its use has been supported to hone trainee skills, increase access to highly sought-after surgeons, and improve cost-effectiveness 1-3. Additionally, prior work in multiple surgical subspecialties has shown that surgical resident involvement improves patient care by bringing additional knowledge and viewpoints, questions, and assistance during cases 4-10. However, common conce...

Introduction: This study was designed to determine the incidence of surgical site infections (SSIs) after orthopaedic surgery in an ambulatory surgery center (ASC) and to identify patient and surgical risk factors associated with SSI. Methods: Patients who underwent orthopaedic surgery at an ASC over a 6.5-year period were reviewed for evidence of SSI. Data on patient and surgical factors were collected, and stepwise multivariate logistic regression determined the risk factors for SSI. Results: The incidence of SSIs was 0.32%. Five independent factors were associated with SSI: anatomic area (odds ratio [OR] = 18.60, 11.24, 6.75, and 4.01 for the hip, foot/ankle, knee/leg, and hand/ elbow versus shoulder, respectively), anesthesia type (OR = 4.49 combined general and regional anesthesia versus general anesthesia), age $70 (OR = 2.85), diabetes mellitus (OR = 2.27), and tourniquet time (OR = 1.01 per minute tourniquet time). Discussion: The risk of infection after orthopaedic surgery in ASCs is low, but patient and surgical factors are independently associated with SSIs.