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

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.

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.

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.

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.