We analysed 54 alumina ceramic-on-ceramic bearings from total hip replacements retrieved at one centre after a mean duration of 3.5 years (0.2 to 10.6) in situ. These implants were obtained from 54 patients (16 men and 38 women) with a mean age of 67 years (33 to 88) who underwent revision for a variety of reasons. Posterior edge loading was found in the majority of these retrievals (32 out of 54). Anterosuperior edge loading occurred less often but produced a higher rate of wear. Stripe wear on the femoral heads had a median volumetric wear rate of 0.2 mm3/year (0 to 7.2). The wear volume on the femoral heads corresponded to the width of edge wear on the matching liner. Anteversion of the acetabular component was found to be a more important determinant than inclination for wear in ceramic bearings. Posterior edge loading may be considered to be a normal occurrence in ceramic-on-ceramic bearings, with minimal clinical consequences. Edge loading should be defined as either anterosuperior or posterior, as each edge loading mechanism may result in different clinical implications.
The authors would like to thank Dr J. M. Martell (University of Chicago, United States), Dr P. Campbell (University of California Los Angeles, United States), and Dr C. Maul (RedLux Ltd, United Kingdom).
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.
- Received January 12, 2012.
- Accepted March 12, 2012.
- ©2012 British Editorial Society of Bone and Joint Surgery