At the 20th annual meeting of the American Association of Hip and Knee Surgeons in Dallas, Texas, November 5 through 7, 2010, a symposium on alternative bearings for total hip replacement reviewed where we have been and where we are headed with regard to alternative bearings.
Ten years ago there was significant concern about polyethylene wear in total hip replacement. This led to the surge in interest in ceramic-on-ceramic and metal-on-metal bearings. As we fast forward 10 years, we have seen the development of new cross-link polyethylenes which significantly decrease wear and hopefully long-term failure of metal-on-polyethylene total hip replacements. Ceramic-on-ceramic bearings have proved to be a very durable and reliable bearing surface but are associated with a 4 to 10 percent incidence of squeaking, and a 1 to 2 percent incidence of fracture of the bearing surface. Metal-on-metal bearings have also demonstrated a very low wear rate over time but increasing concerns over metal debris and metal ion toxicity have led to a significant decrease in the use of metal-on-metal bearings except in the very young, active male.
Long-term followup will determine which of the bearings proves to be the most durable at 15, 20, and 25 years, but over the first 10 years we have learned quite a bit about the pluses and minuses of each bearing surface. A survey of 600 enrollees at this meeting indicated that the overwhelming majority of joint replacement surgeons favor metal-on-polyethylene bearings at this point in time, with a decreasing number of surgeons using ceramic-on-ceramic or metal-on-metal.