The Clinical Performance of UHMWPE in Knee Replacements

Examples of contemporary fixed-bearing knee replacement components. (A) Scorpio PS total knee prostheses (B) Duracon total knee prostheses and (C) Eius unicondylar prostheses. Images provided courtesy of Stryker Howmedica Osteonics (Mahwah, NJ). 

Although knee arthroplasty enjoys a remarkable clinical track record, problems with wear and fatigue damage of UHMWPE continue to limit the longevity of both unicondylar and bicondylar knee replacement components. Unlike in the hip, where radiographic techniques have been developed to quantify in vivo wear rates, there currently exist no standard and widely accepted techniques for tracking the clinical performance of UHMWPE in patients with knee replacement. Thus, today the most effective way to evaluate the in vivo performance of UHMWPE continues to be the analysis of retrieved components from revision surgery or from autopsy donations. 

This chapter contains four main sections covering TKA and, where applicable, UKA. The first section reviews the biomechanical considerations of knee arthroplasty that distinguish it from hip replacement. The second section describes the survivorship of TKA and UKA, and outlines measures of clinical performance for UHMWPE in knee arthroplasty. The third section is devoted to wear and osteolysis in TKA. In the final section of this chapter, alternatives to metal-on-conventional UHMWPE articulation for knee arttiroplasty are described. 

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Chapter 8 The Clinical Performance of UHMWPE in Knee Replacements... 

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