Is Immediate Postoperative Mechanical Axis Associated with the Revision Rate of Primary Total Knee Arthroplasty? A 10-Year Follow-up Study

Abstract

BACKGROUND: Achieving neutral limb alignment during total knee arthroplasty (TKA) has been considered an important determinant in the long-term prosthesis survival. The purpose of this study was to evaluate the association between the immediate postoperative mechanical alignment of the lower limb and the rate of revision TKA by comparing an acceptable mechanical axis group (within ± 3° from neutral alignment) and an outlier group (> 3° deviation from neutral alignment). METHODS: Between 2000 and 2006, clinical and radiographic data of 334 primary TKAs were retrospectively reviewed to determine the 10-year Kaplan-Meier survival rate. Patients were divided into acceptable and outlier groups according to the mechanical axis checked postoperatively within a month. Clinical outcomes were assessed using Hospital for Special Surgery, Knee Society Score, and Western Ontario and McMaster Universities Osteoarthritis Index score preoperatively and at the final follow-up. Postoperative complications and revision rates were also evaluated. RESULTS: = 0.25). CONCLUSIONS: Restoration of neutral limb alignment is a factor that can result in a lower revision rate and higher longevity in TKA. However, there were no significant differences in clinical outcomes between the two groups.