General Anesthesia Leads to Increased Adverse Events Compared With Spinal Anesthesia in Patients Undergoing Unicompartmental Knee Arthroplasty.

Background: The volume of unicompartmental knee arthroplasty (UKA) has increased dramatically in recent years with good reported long-term outcomes. UKA can be performed under general or neuraxial (ie, spinal) anesthesia; however, little is known as to whether there is a difference in outcomes based on anesthesia type. The purpose of the present study is to compare perioperative outcomes between anesthesia types for patients undergoing primary elective UKA.

Methods: Patients who underwent primary elective UKA from 2007 to 2017 were identified from the American College of Surgeons-National Surgical Quality Improvement Program Database. Operating room times, length of stay (LOS), 30-day adverse events, and readmission rates were compared between patients who received general anesthesia and those who received spinal anesthesia. Propensity-adjusted multivariate analysis was used to control for selection bias and baseline patient characteristics.

Results: A total of 8639 patients underwent UKA and met the inclusion criteria for this study. Of these, 4728 patients (54.7%) received general anesthesia and 3911 patients (45.3%) received spinal anesthesia. On propensity-adjusted multivariate analyses, general anesthesia was associated with increased operative time (P < .001) and the occurrence of any severe adverse event (odds ratio [OR], 1.39; 95% confidence interval [95% CI], 1.04-1.84; P = .024). In addition, general anesthesia was associated with higher rates of deep venous thrombosis (OR, 2.26; 95% CI, 1.11-4.6; P = .024) and superficial surgical site infection (OR, 1.04; 95% CI, 0.6-1.81; P < .001). Finally, general anesthesia was also associated with a reduced likelihood of discharge to home (OR, 0.72; 95% CI, 0.59-0.88; P < .001). No difference existed in postoperative hospital LOS or readmission rates among cohorts.

Conclusion: General anesthesia was associated with an increased rate of adverse events and increased operating room times as well as a reduced likelihood of discharge to home. There was no difference in hospital LOS or postoperative readmission rates between anesthesia types.