CLINICAL OUTCOME FOLLOWING BILATERAL STAGED TOTAL KNEE ARTHROPLASTY USING THE ANATOMIC MODULAR KNEE

Abstract

Introduction: Clinical outcome studies have shown excellent results following unilateral total knee arthroplasty (TKA). A wide Pub Med search failed to find any literature on the outcome of results following bilateral staged TKA.

Aim: To determine the clinical outcomes of patients undergoing bilateral staged TKA.

Material & Methods: Patients who underwent bilateral staged TKA between 1994 – 2002 were assessed using the Knee Society Score (KSS) and Western Ontario and MacMaster Osteoarthritis Index (WOMAC) scoring systems. They were also asked regarding which TKA they considered ‘better’ and why.

Results: We clinically reviewed 110 patients who underwent bilateral staged TKA. The mean clinical follow-up time was 5.13 years. The mean pre-operative KSS was 95.8 for the right knee and 95.5 for the left knee. The mean post-operative KSS was 154.1 for the right knee and 155.9 for the left knee. Patients mean postoperative WOMAC scores for the right knee were; Pain – 1.67, Stiffness – 1.17 and Function – 10.78. Patients mean post-operative WOMAC scores for the left knee were, Pain – 1.77, Stiffness – 1.14 and Function – 10.69. Objectively there was no statistical significance between right and left KSS pre-operatively. There was no statistical significance between right and left KSS and WOMAC scores post-operatively. Subjectively, 44 patients reported their first TKA was ‘better’ than their second. 48 patients reported both TKA’s were as good as each other. 18 patients reported their second TKA was ‘better’ than their first. The 2 main reasons why one TKA was better than the other were pain and range of movement.

Conclusion: Objectively, staged bilateral TKA results in equally good outcome. Subjectively, the first TKA is ‘better’ or equal to the second TKA in 84% of cases. We feel that this information is important during counseling of patients undergoing bilateral staged TKA.