SURVIVORSHIP ANALYSIS OF 3,234 PRIMARY KNEE ARTHROPLASTIES IMPLANTED OVER A 26 YEAR PERIOD. A STUDY OF EIGHT DIFFERENT IMPLANT DESIGNS

Abstract

3610 primary and revision total knee replacements were performed at our hospital between 1969 and 1995. We conducted a survivorship analysis of 3234 primary total knee replacements to construct life tables and calculate survival curves. Each knee replacement was entered once only. Revision was defined as the end point. Data was collected both from patient records and by postal questionnaire. Eight types of knee prostheses were evaluated with best-case and worst-case scenarios compared over a 5, 10 and 15 year period.

The evidence suggests that certain types of prosthesis are more liable than others to fail or to fail early. The “Condylar type devices” which include the Total Condylar, Press Fit Condylar (PFC), Kinematic, Kinemax and Anatomic Modular Knee (AMK) have very similar survivorship curves and in the main have performed well up to a 10 year period. The LCS mobile bearing knee performed extremely well at 5 years. The Attenborough knee had an inferior result while the Load Angle Inlay (LAI) which was a very early resurfacing arthroplasty had the poorest results in terms of survivorship.