Evaluation of a hip joint simulator

To evaluate the functioning of the Durham hip joint wear simulator, the wea r rates of ultra high molecular weight polyethylene (UHMWPE) and polytetraf luoroethylene (PTFE) acetabular cups articulating against 22 mm diameter co balt-chromium-molybdenum (CoCrMo) femoral heads were studied. A wear test w as conducted in a lubricant of distilled water at 37 degrees C for a durati on of 4.8 million cycles. The average penetration rate for the CoCrMo femor al heads against UHMWPE acetabular cups was 0.03 mm/10(6) cycles, while pen etration rate for PTFE cups was some twenty times greater. These results ar e of a similar order of magnitude to other simulator studies in distilled w ater and are in a similar ratio to clinical data.