Orthopedics Today, October 2012
“Ceramic heads appear to reduce wear against modern highly crosslinked polyethylene,” study presenter
Parvizi, an Orthopedics Today Editorial Board member, touted the superiority of ceramic components and noted that he is “not aware of any biological response to ceramic particles.” He added that ceramics have increased lubrication, smaller grain sizes than cobalt chromium and boast a harder surface.
“If you look at scanning microscopy, cobalt chromium has those troughs and valleys,” Parvizi said. “The ceramic head is extremely polished and smooth. It is biologically inert. The wear of ceramic-on-ceramic is the best we have today compared to every other bearing surface.”
“If you have got a 4-mm polyethylene, it will last 40 years, theoretically, against metal. It will last 58 years against ceramic,” Parvizi said. “Is that 18 years over the course of 40 years significant? It is for me, and I am sure it is for my patients. If you were the one to choose between metal and ceramic, I hope you will choose ceramic, because it probably does have a longevity compared to the metal.”
Despite the reduced wear rates for ceramic-on-polyethylene, Parvizi noted that trunnionitis may still present a problem. He, therefore, advises a differential diagnosis of possible trunnion erosion in cases with pseudotumor around the hip. – by Renee Blisard Buddle