IS WEAR OF DUAL MOBILITY CUP LOWER OR UPPER THAN CONVENTIONAL CUP? RESULTS ANALYSIS OF AN IN VITRO STANDARD TEST

IntroductionPolyethylene (PE) wear is clearly linked to total hip arthroplasty (THA) failure, leading to osteolysis and decreasing survivorship rates. Dual mobility cups (DMC) are widely used to prevent or treat THA instability. However some studies have pointed PE wear risk as a “dual wear” risk. Hip wear simulation is usually used to understand factors influencing wear and to differentiate design, PE types and materials performances. To date, few works have been published studying dual mobility insert wear.ObjectivesOur objective was to evaluate wear of DMC with comparison with a fixed single articulating hip design and to measure wear under same conditions (loading cycle, temperature, sterilization, material and surface roughness).MethodsThe test bench includes one station for a control sample and one for dynamic test. Those are driven independently one from the other. Two electrical actuators applied the forces and two forces sensors putted on the fixing plate of the acetabular part gave the correspon...