Abstract
Few studies assess the impact of prior knee surgery on long-term total knee arthroplasty (TKA) outcomes. This study investigates the effect of prior ligament reconstruction on TKA revision rates, modes of failure, and patient-reported outcome measures (PROMs). All males undergoing primary TKA from January 1999 to July 2024 from the New Zealand Joint Replacement Registry were included, with a median follow-up of 7.2 years. Patients with previous knee ligament reconstruction were compared with those without. The primary outcome was all-cause revision with results stratified by age. Secondary outcome measures were modes of failure and 6-month and 5-year Oxford Knee Scores (OKS). Age, sex, American Society of Anesthesiologists (ASA) score, body mass index, fixation, bearing, patella resurfacing, and surgery year were examined as potential confounders. Revision rates with 95% confidence intervals (CI) were calculated using Poisson approximation. Multivariate Cox proportional hazards assessed the independent relationship between ligament reconstruction and revision. A total of 73,355 TKAs were performed; 1,440 (2.0%) with previous ligament reconstruction surgery and 71,915 (98.0%) without. Patients with previous ligament reconstruction were younger (58.7 [8.7] vs. 68.3 [8.8] years) and had lower ASA scores, less cemented fixation, more posterior-stabilized bearings, and more patella resurfacing (all p < 0.001). The unadjusted risk of revision was higher in those with previous ligament reconstruction (hazard ratio [HR]: 1.90 [95% CI: 1.54-2.35], p < 0.001) with 15-year cumulative percent revision (CPR) 12.9 versus 6.1%. This difference was more profound in younger patients (age < 40: 15-year CPR 33.3 vs. 10.0%; age 40-54: 15-year CPR 16.6 vs. 11.8%). Adjusted multivariate analysis showed a nonstatistical difference in revision risk (HR: 1.25 [95% CI: 0.99-1.59], p = 0.064). No statistical differences for modes of failure and no clinically significant differences in 6-month nor 5-year OKS were seen. In men with previous knee ligament reconstruction surgery undergoing TKA, revision risk appeared higher, particularly in younger patients, but the difference was attenuated and no longer statistically significant after adjustment for confounders, especially in younger patients, but PROMs remain similar.