Fatigue testing of a proximal femoral hip component

The Gothenburg Osseointegrated Titanium (GOT) implant is a novel total hip replacement including a metaphyseal loading proximal femoral component fixed in the retained femoral neck. Endurance testing was performed under conditions analogous to ISO 7206-4: 1989. The cement-free implant is not fixed distally within the intramedullary canal, so distal embedding (as specified in the standard) would have been unrealistic. Instead glass-fibre-reinforced epoxy (GFRE) bushings were used to model reduced bone support mid-length at the medial cortex and distally at the lateral cortex. Such support simulated proximal bone loss, realistically reproducing the effect of osteolysis or fixation failure. Under such conditions the component survived unbroken for 10 million cycles at 3.0 kN peak load.