10-Year Outcomes of Total Knee Arthroplasty for Fracture Compared to Osteoarthritis Indications.

Abstract

Total knee arthroplasty (TKA) performed after periarticular knee fracture is technically complex and has demonstrated higher complication rates within five years compared with osteoarthritis (OA)-indicated TKA. Comparative outcomes beyond five years in a large United States cohort remain limited. We compared 10-year surgical outcomes after fracture-indicated versus OA-indicated primary TKA. A retrospective cohort study was performed using a large, nationally federated electronic health record database. Adults undergoing primary TKA were categorized as fracture-indicated (history of distal femoral or proximal tibia fracture with post-traumatic OA within five years prior to TKA, excluding primary OA) or OA-indicated (primary OA within five years, excluding prior knee fracture and post-traumatic OA). Exclusions included inflammatory arthritis, joint infection, pyogenic arthritis, and bone malignancy. Cohorts were propensity-score matched 1:1 for age, sex, race, ethnicity, Charlson Comorbidity Index, overweight and obesity, nicotine dependence, osteoporosis without a current pathological fracture, and vitamin D deficiency. The primary 10-year outcomes were all-cause revision, periprosthetic joint infection (PJI), aseptic loosening, periprosthetic fracture (PPF), and secondary fragility fracture. After matching, 1,062 patients remained in each cohort. At 10 years, fracture-indicated TKA demonstrated a higher risk of revision (5.8 versus 3.0%, P = 0.002; relative risk (RR) = 1.91, 95% confidence interval (CI): 1.26 to 2.90) and PJI (4.7 versus 2.3%, P = 0.003; RR = 2.06, 95% CI: 1.27 to 3.33). Aseptic loosening and secondary fragility fracture did not differ. Time-to-event analysis showed increased revision (hazard ratio = 3.35, 95% CI: 2.13 to 5.27; log-rank P < 0.001). Fracture-indicated TKA was associated with significantly higher 10-year risks of PJI and revision compared with OA-indicated TKA, supporting heightened perioperative infection mitigation and extended surveillance in this high-risk population.