Trends in Complications and Outcomes in Patients Aged 65 Years and Younger Undergoing Total Knee Arthroplasty: Data From the American Joint Replacement Registry

The purpose of this study was to identify common complications and the rates of readmission and revision in total knee arthroplasty (TKA) patients younger than 65 years. METHODS: Using the American Joint Replacement Registry, we conducted a retrospective review of all TKAs done in patients aged 18 to 65 years from 2012 to 2020. Demographic factors such as age, sex, Charlson Comorbidity Index (CCI), and preoperative Veterans RAND 12-Item Health Survey Physical Component Summary (VR-12 PCS) scores were collected. We excluded patients older than 65 years and revision, oncologic, and nonelective cases. Primary outcomes included cumulative revision rate, 90-day readmission rate, and reason for revision. Univariate analysis and the Kaplan-Meier method were used. RESULTS: Six thousand one hundred seventy-nine patients were included. The average age was 58.8 years (SD 5.5 years), 61% were female, 82% were White, and 88% had a CCI of 0 (1 = 8% and ≥2 = 4%). The mean follow-up was 42.51 months. Seventy-four patients (1.2%) underwent revision. Sixty-nine patients (1.1%) were readmitted within 90 days. No factors assessed increased revision rates. Revision-free survivorship was 98.7% (95% CI 98.4 to 99.0) and 98.6% (95% CI 98.2 to 99.0) at 5 and 8 years, respectively. Infection (15%), aseptic loosening (14%), and instability (12%) were the most common indications for revision. CONCLUSION: TKA done in young and presumed active patients has excellent survivorship. Long-term follow-up is needed to assess survival trends in this growing population.