Survival analysis of Primary Total Knee Arthroplasty in a Teaching Hospital: a study of 977 cases

Abstract

Introduction: The study aimed to report the survivorship for primary total knee arthroplasty (TKA) in a teaching hospital. Materials and Methods: Data from the hospital’s prospective joint registry on all patients undergoing primary TKAs in Queen Mary Hospital from 2000 to 2007 were identified and reviewed. Results: From 2000 to 2007, 977 TKAs (799 female, 178 male; 482 left-sided and 495 right-sided) were performed. Their mean (± standard deviation) age at operation was 68.4 ± 8.7 years. The primary diagnoses included osteoarthritis (n = 919), rheumatoid arthritis (n = 47), and others (n = 11). The mean follow-up duration was 7.8 ± 3.2 years. Posterior stabilising prostheses were used in 550 (56.3%) knees while rotating platform in 424 (43.4%) knees and constrained prostheses in 3 (0.3%) knees. Also, 36 (3.7%) patients underwent revision surgery (24 aseptic loosening, 11 infection, and 1 peri-prosthetic fracture) with a mean survivorship of 7.7 years. Of the 24 aseptic loosening cases, 19 had low contact stress prostheses. Using revision as an end-point, the 12-year survivorship was 94.2%. When using aseptic loosening as an end-point, the 12-year survivorship was 95.6%, and that for using infection as an end-point was 98.7%. Male sex was found to be a risk factor for infection (odds ratio = 7.8, p = 0.005). Discussion and Conclusion: Primary TKAs had satisfactory results in Queen Mary Hospital. The survivorship is comparable to the results of global joint registries.