The effect of different assembly loads on taper junction fretting wear in total hip replacements

Variability in the magnitude of the impaction force applied by surgeons to assemble a hip prosthetic head to a femoral stem could be a cause of increased wear in taper junctions. This study investigates the effect of varying the magnitude of the assembly force on fretting wear at the taper over a 10 year period using a 3D finite element model and wear algorithm. It is demonstrated that an increase in assembly force results in a reduction in fretting wear and it is recommended that surgeons should apply an impact force of at least 4 kN to minimise wear rates. The wear patterns and wear rates presented are comparable with observation and measurement of those seen in retrieved prostheses.