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). We are unable to find in the medical literature 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 clinically 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 post-operative 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 1st TKA was ‘better’ than their 2nd. 48 patients reported both TKA’s were as good as each other. 18 patients reported their 2nd TKA was ‘better’ than their 1st. 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 equal good outcome. Subjectively, the 1st TKA is ‘better’ or equal to the 2nd TKA in 84% of cases. We feel that this information is important during counseling of patients undergoing bilateral staged TKA.