Outcomes of elective total knee arthroplasty in nonagenarians and centenarians

Introduction: Among the fastest growing age demographics are individuals in their ninth decade of life. As the population in the United States ages and life expectancy increases, more elderly individuals are pursuing elective orthopaedic procedures, including total knee arthroplasty (TKA). Methods: The American College of Surgeons NSQIP database was used to identify patients undergoing elective TKA between January 1st, 2007 and December 31st, 2017. Exact propensity score matching was used to match patients aged 90 years and older to patients between 65-89 years-old based on demographic factors and comorbidities. 30-day outcome measures and complications were compared between the two age groups. Binary logistic regression was used to identify risk factors for adverse events in the matched nonagenarian patients. Results: 150,326 patients were included in the final cohort (65-89 year-olds: 149,721; 90+ year-olds: 605). 585 patients aged 65-89 years-old were then propensity matched to 585 patients aged 90+ years-old. Statistically similar rates of reoperation (P=0.207), mortality (P>0.999), and overall medical complications (P=0.055) were noted between the two groups; however, nonagenarians and centenarians were more likely to have an unplanned hospital readmission (P=0.049) and non-home discharge (P<0.001). 90+ year-olds were less likely to experience bleeding requiring transfusion (P<0.001). Hypertension, ASA class IV, and a history of bleeding disorder were independent risk factors for adverse outcomes. Conclusion: TKA can be a safe and viable treatment option for nonagenarians and centenarians and recommend that comorbidity profiles, rather than age, principally guide shared clinical decision making.