Ceramic/Polyethylene
Wear Couple
Ceramic ball heads: Less polyethylene wear debris than with metal ball heads
If a metal ball head is used in combination with a polyethylene (plastic) cup insert, the wear rate is especially high and as a consequence, so is the risk of early loosening of the prosthesis. Clinical studies demonstrate that the polyethylene cup insert can wear by more than 0.2 mm per year. Frequently the surface of the metal head exhibits fine scratches, which can further increase the wear rate by a large amount. In laboratory studies using scratched metal ball heads an increase in the amount of polyethylene wear debris of roughly 30-times was obtained.
Ceramic ball heads reduce the wear of the polyethylene cup inserts to less than 0.1 mm per year. Furthermore in contrast to a metal surface, the ceramic surface cannot be scratched. Ceramic/polyethylene (BIOLOX®forte/polyethylene) wear couples can reduce the rate of implant loosening, implant revision and associated complications by 2 to 5 times in comparison with metal/polyethylene wear couples.
These conclusions are based on scientific articles and medical publications.