Long-term survivorship analysis of cruciate-sparing versus cruciate-sacrificing knee prostheses using meniscal bearings.

A comprehensive, interchangeable, low-contact-stress, mobile-bearing knee prosthesis system was developed and used over a 12-year period with both cemented and cementless fixation. Individual components of the system included a bicruciate-retaining meniscal bearing, a posterior cruciate-retaining meniscal bearing, and a cruciate-sacrificing, rotating-platform tibial component mated to the same femoral and rotating patellar components. Survivorship analysis of each implant type was performed to identify specific failure modes and trends for long-term survival of the implants in a wide variety of primary knee arthroplasties. Clinically, there were 46 prostheses of the bicruciate type followed for up to 12 years, 57 prostheses of the posterior-cruciate type followed for up to six years, and 108 prostheses of the rotating-platform type followed for up to ten years. All knees in this study had rotating-bearing patellar prostheses. Cumulative survivorship analysis using an end point of implant revision or a poor knee score revealed a small early failure rate of each implant in the first three years, associated with technical positioning or undersizing errors. This study indicates a predictable long-term survival of both cruciate-retaining and cruciate-sacrificing mobile-bearing knee prostheses as well as rotating-bearing patellar prostheses when used in primary knee arthroplasties that minimized technical errors of insertion.