Friction between head and cup is a primary factor for survival of total hip joint replacement (THR) and its gliding surfaces. In up to 40% of all revisions, the cup or inlay must be replaced as result of friction-induced wear [1]. Aim of the study was to measure the friction-induced temperature increase in vivo in THR and to identify possible individual parameters of influence. For the in vivo measurement, an instrumented implant with an Al2O3/XPE-pairing and an integrated temperature sensor was used [Fig. 1] [2]. Ten patients were provided with such an instrumented implant. Up to now, long time measurements were performed on six of these patients (Ø63y, Ø89kg). During these measurements, the subjects walked Ø60min on a treadmill with 4km/h. The investigation was performed Ø61 (43–70) months post operatively. Short time (Ø3min) in vivo load measurements during walking on treadmill were already available from the other four patients. These data were used to calculate the peak temperatures after 60mins of walking by using a model, based on the long time measurements.Introduction
Methods
