Friction and wear properties of metal/metal hip joints : application of a novel testing and analysis method

Journal
Materials science and engineering technology  
Volume
32
Issue
12
Start Page
891
End Page
896
Citation
Materials science and engineering technology 32 (12): 891-896 (2001)
Publisher DOI
10.1002/1521-4052(200112)32:12<891::AID-MAWE891>3.0.CO;2-Y
Scopus ID
2-s2.0-0035527869
Publisher
Wiley-VCH
Insufficient understanding of tribological behaviour of total joint components is considered as one of the major reasons for premature prosthesis failure. In the previous years, wear modes and mechanisms of artificial hips have been intensively studied using testing machines applying continuous motion and load profiles. Human locomotion, however, is of erratic shape containing motion interruptions among other irregularities. These occurring resting phases could influence adhesive friction at the artificial articulation with possible effects on wear and loosening. Initial frictional behaviour after resting periods and subsequent wear of metal-on-metal hip components have been investigated. While the initial frictional moment of artificial hip components was found to increase significantly with increasing resting duration, wear was hardly affected. These results therefore rather point to an interlocking phenomenon than adhesion. Still, the results are of concern because the increase in friction is likely to occur under physiological conditions too and may cause tangential stress peaks at the bone/ implant interface accelerating fatigue failure. In particular, big head sizes should be used with caution because the frictional moment is a function of coefficient of friction and ball diameter.
DDC Class
610: Medicine, Health