Overlapping Surgery in Primary Total Knee Arthroplasty: Are 6-Week Complications Worse than Single Operating Room Scheduling?

Background: Overlapping surgery is common in high-volume total knee arthroplasty (TKA) practices and has come under recent scrutiny in the press. The aim of this study was to evaluate differences in 6-week clinical and radiographic outcomes for primary TKA patients between single and overlapping operating room (OR) days. Methods: We retrospectively reviewed individual patient records of a consecutive series of primary TKAs with complete 6-week follow-up performed by a single academic surgeon between 2008-2016 (N= 452). Patients were stratified by single vs. overlapping OR days. 177 patients (39%) had an overlapping surgery. Age, body mass index (BMI), Charlson Comorbidity Index (CCI) and American Society of Anesthesiologists (ASA) class were recorded to assess for confounding variables. Outcomes included anesthesia time, 6-week readmission, unplanned return to OR, medical and surgical complication, and 6-week radiographic alignment. Results: There were no significant differences in anesthesiology time (165.5 vs 164.5 min, p=0.85), medical or surgical complication rates (10.5% vs 6.2%, p=0.11), 6-week readmissions (4.4% vs 1.7%, p=0.12), or return to OR (1.8% vs 1.7%, p=1.00) before or after adjusting for age, BMI, gender, ASA and CCI. There was no difference between overlapping and single OR cohorts in rate of neutral coronal alignment (2°-8° valgus) (98.3% vs 98.9%, respectively, p=0.68) or presence of periprosthetic lucency (p=0.43). Conclusions: This study demonstrates no differences in 6-week clinical or radiographic outcomes between patients undergoing primary TKA on single versus overlapping OR days. These results support the safe practice of overlapping surgical scheduling in high-volume primary TKA centers.Level of Evidence: III.