Increased Postoperative Complications in Patients with Sleep Apnea Undergoing Unicompartmental Knee Arthroplasty

Abstract

Introduction: Sleep apnea has been shown to affect cognition, immunity, and bone mineralization negatively. The effects of sleep apnea on unicompartmental knee arthroplasty outcomes are not well defined. The purpose of this study is to assess postoperative medical and implant- related complications, and healthcare utilization in patients with and without sleep apnea undergoing unicompartmental knee arthroplasty. Methods: A retrospective review of a private insurance claims database was conducted from 2010 to 2021. All cases of unicompartmental knee arthroplasty and those with a prior diagnosis of sleep apnea were identified using their corresponding diagnosis and procedural codes. Patients undergoing unicompartmental knee arthroplasty with a diagnosis of sleep apnea were matched to control patients 1:2 based on demographic and comorbidity profiles. Outcomes assessed were 90-day medical complications, 2-year implant complications, cost of care, length of stay, and 90-day readmission rates. Results: A total of 16,080 sleep apnea patients were matched to 31,684 control patients. The sleep apnea group had significantly higher rates of all 90-day medical complications when compared to the control group (all P<0.01). Sleep apnea patients also had significantly greater odds of falls (OR, 3.04; CI, 2.71- 3.41, P<0.001). Likewise, the sleep apnea group had significantly greater odds of prosthetic joint infection, dislocation, mechanical loosening, and periprosthetic fracture than the control group (all P<0.01). There were no significant differences in the odds of arthrofibrosis (p=0.186). Additionally, mean cost ($3,141 vs. $2,895, P<0.001) and mean length of stay (3.9 vs. 1.9 days, P<0.001) were significantly greater in the study group. Conclusions: Sleep apnea in patients undergoing unicompartmental knee arthroplasty is associated with a significant risk of medical and implant-related complications, especially pneumonia, thromboembolic complications, and falls. It is prudent for orthopedic surgeons to identify those with sleep apnea, with possible early intervention prior to surgery to improve outcomes.