Influence of Health Insurance Coverage on the Survival Rate for Primary Total Knee Arthroplasty: Minimum 5-Year Follow-Up Analysis

This study investigated whether differences in survival rates and clinical outcomes exist in patients undergoing TKA by insurance type: National Health Insurance (NHI) vs. Medical Aid Program (MAP). This study conducted a retrospective analysis of 762 TKAs (NHI, n = 505; MAP, n = 257) with a mean follow-up of 8.4 +/- 1.8 years. Patient-reported outcomes (PROMs) were evaluated using the American Knee Society's (AKS) score at the final follow-up. The survival rate of each group was analyzed using Kaplan-Meier survival analysis. Any postoperative complications and readmissions within 90 days of discharge were recorded and compared between the groups. There were no between-group differences in pre- to postoperative improvement in AKS scores. The estimated 10-year survival rates were 98.5% in the NHI group and 96.9% in the MAP group, respectively, with no significant differences (p = 0.48). However, the length of hospital stay (LOS) was significantly longer in the MAP group than in the NHI group (13.4 days vs. 13.1 days, p = 0.03), and the transfer rate to other departments was significantly higher in the MAP group than in the NHI group (3.9% vs. 1.4%, p = 0.04). Readmission rates for orthopedic complications for 90 days were 3.0% in the NHI group and 3.5% in the MAP group, respectively (p = 0.67). Patients' insurance type showed similar survival rates and clinical outcomes to those of primary TKA at a mean follow-up of 8.4 years, but the LOS and rate of transfer to other departments during hospitalization were influenced by insurance type.