Initial concerns about ceramic-on-ceramic constructs for use in total hip arthroplasty are somewhat muted by more recent developments in the technology, one surgeon said during a recent presentation.
“Ceramic-on-ceramic is a nice option to avoid [wear],” Hari P. Bezwada, MD, said at the International Congress for Joint Reconstruction San Diego 2012 meeting, which was held in collaboration with Orthopedics Today. “It is a hard-on-hard bearing and a low-wear construct. One of the nice things about ceramic is it is the hardest scratch-resistant surface we know. If it is scratch-resistant it is going to be less prone to other issues.”
Bezwada made note of one downside to the material being scratch resistant: It could be brittle.
“One of the concerns has been about ceramic fractures, and a lot of this had to do with early tolerances,” he said. “The fracture incidence now of modern ceramics for femoral heads and acetabular liners is very low. A big reason for this is grain size, which has a lot to do with processing.”
According to Bezwada, ceramic-on-ceramic constructs are currently in their fourth generation. The implants are twice as strong as those of the third generation, he said, and have already displayed good 10-year function.
When it comes to retrieval, Bezwada said the wear for ceramic-on-ceramic implants is substantially less than that found in polyethylene. Less reactive particles, he said, mean less osteolysis and less concern at the time of revision. Hard-on-hard bearings also allow for the use of larger heads, which he said affords greater range of motion and stability.
“You also have revision options now,” Bezwada said. “One of the concerns we have known before is if you are doing revision with a damaged trunnion, would you be able to place a ceramic head? Now, with these titanium inserts, you have that option.”
Bezwada cautioned that hard-on-hard bearings are still unforgiving, meaning component position is more critical than with more forgiving bearing surfaces.
“Ceramic-on-ceramic has the very lowest wear couple,” Bezwada said. “It is technique dependent, so make sure your components are properly positioned. The fracture risk going forward with the fourth generation is probably exceedingly low. You do not have to worry about metal hypersensitivity.”
“Overall, I think it is the better option for younger patients,” he said.
- Bezwada HP. Why ceramic-on-ceramic is the best bearing option in THA. Presented at the International Congress for Joint Reconstruction San Diego 2012 in collaboration with Orthopedics Today. April 27-29. San Diego.
- Disclosure: Bezwada is a consultant for Biomet and Zimmer, and a member of the Gynzyme Biosurgery speaker’s bureau.