Protocol for clinically-relevant and severe wear simulator testing of total hip and knee implants

摘要

Traditionally, hip and knee implants have been tested in simulators under clean, ideal conditions. However, surfaces of retrieved total hip arthroplasty femoral heads and total knee arthroplasty femoral components reveal that scratching occurs in vivo. When an implant is placed in a patient, initially-smooth hard implant surfaces become roughened by abrasive particles such as bone cement, metal, or bone debris. In vitro studies have shown that scratches, particularly those at an angle to the direction of motion, can increase ultra-high molecular weight polyethylene (UHMWPE) wear. As younger and more active patients are receiving implants, implant longevity becomes more critical. A protocol has been developed that allows aggressive and clinically-relevant wear testing of implants and should better predict implant endurance.