Unicompartmental Knee Arthroplasty in Octogenarians versus Younger Patients: A Comparison of 30-Day Outcomes

As the United States' octogenarian population (persons 80-89 years of age) continues to grow, understanding the risk profile of surgical procedures in elderly patients becomes increasingly important. The purpose of this study was to compare 30-day outcomes following unicompartmental knee arthroplasty (UKA) in octogenarians with those in younger patients. The American College of Surgeons National Surgical Quality Improvement Program database was queried. All patients, aged 60 to 89 years, who underwent UKA from 2005 to 2016 were included. Patients were stratified by age: 60 to 69 (Group 1), 70 to 79 (Group 2), and 80 to 89 years (Group 3). Multivariate regression models were estimated for the outcomes of hospital length of stay (LOS), nonhome discharge, morbidity, reoperation, and readmission within 30 days following UKA. A total of 5,352 patients met inclusion criteria. Group 1 status was associated with a 0.41-day shorter average adjusted LOS (99.5% confidence interval [CI]: 0.67-0.16 days shorter, p < 0.001) relative to Group 3. Group 2 status was not associated with a significantly shorter LOS compared with Group 3. Both Group 1 (odds ratio [OR] = 0.15, 99.5% CI: 0.10-0.23) and Group 2 (OR = 0.33, 99.5% CI: 0.22-0.49) demonstrated significantly lower adjusted odds of nonhome discharge following UKA compared with Group 3. There was no significant difference in adjusted odds of 30-day morbidity, readmission, or reoperation when comparing Group 3 patients with Group 1 or Group 2. While differences in LOS and nonhome discharge were seen, octogenarian status was not associated with increased adjusted odds of 30-day morbidity, readmission, or reoperation. Factors other than age may better predict postoperative complications following UKA.