Total knee arthroplasty in patients with varus deformities greater than ten degrees: survival analysis at a mean ten year follow-up.

ABSTRACT

INTRODUCTION: Total knee arthoplasty (TKA) is a secure procedure with more than 90% survival at ten years. The purpose of this study was to report both clinical and radiological outcomes of TKA with a varus > 10°. The second objective was to identify risk factors for failure or bad clinical results. Our hypothesis was that results and survey are comparable to TKA with lesser deformities. METHODS: Eighty-two TKA (69 patients) between January 2004 and December 2008 with a varus > 10° were reviewed retrospectively. The endpoints were clinical (range of motion, IKS knee score, Oxford, and SF-12) and radiological (HKA post-operative and the existence of radiolucent lines or loosening at last follow-up). RESULTS: Sixty-three TKA (55 patients) were assessed with a mean follow-up of 10.9 years. The global IKS score significantly increased (p = 0.04). Seven TKA needed a revision two for sepsis, four for aseptic loosening, and one for polyethylene wear, with an overall survival of 91.6% at ten years. For aseptic loosening, the survival rate was 94.7% at ten years. Risk factors for failure were age (p = 0.001), weight (p = 0.04), and a post-operative HKA lesser than 175° (p = 0.05) for aseptic loosening. DISCUSSION: The hypothesis was confirmed the results showed a significant improvement of function and quality of life with a survival rate comparable to those found in the literature for greater varus but also inferior to 10°. Three risk factors have been identified suggesting increased surveillance in these cases. CONCLUSION: The results of this survey confirm the work hypothesis. Total knee arthroplasty in patients with important axial deformities is a confirmed, reliable, patient-friendly and predictable good outcome procedure.