Lombardi v. Schmalzried: Ceramic-XLPE in Patients <60: The New Standard
OTW Staff • Thu, March 1st, 2018
This week’s Orthopaedic Crossfire® debate was part of the 33rd Annual Current Concepts in Joint Replacement® (CCJR®), Winter meeting, which took place in Orlando. This week’s topic is “Ceramic-XLPE in Patients <60: The New Standard.” For is Adolph V. Lombardi, Jr., M.D., Mt. Carmel New Albany Surgical Hospital, New Albany, Ohio. Opposing is Thomas P. Schmalzried, M.D., Joint Replacement Institute, Los Angeles, California. Moderating is Clive P. Duncan, M.D., F.R.C.S.(C), University of British Columbia, Vancouver, British Columbia, Canada.
Dr. Lombardi: Ceramic seems to be becoming a more significant trend in the United States. Although I would give it to Tom that there are more metal-on-polyethylene performed.
Why ceramics? Because they’re hard, they’re scratch-resistant, they’re excessively wettable. They have very low wear and they’re inherently stable. There’s been extensive experience with BIOLOX, for example. From 1974—40 years of experience. A lot of publications. Ten-plus years of published clinical results. And if you’re worried about fracture, a manufacturer database and three registries show it’s 0.001%. Fracture of these devices is minimum for femoral heads and certainly less as you get to the larger heads.
Now, if you look at wear it’s a pretty significant difference.
In a simulator study, a smooth ceramic head resulted in 34% less wear and 90% less wear with a rough ceramic head when compared to matched metal heads on cross-linked polyethylene. Further, the ceramic on conventional polyethylene is much better than the metal on conventional polyethylene, but not as dramatic a difference between ceramic versus metal on highly cross-linked polyethylene.
In one RCT [randomized control trial] published in 2009, which looked at zirconia on non-cross-linked polyethylene versus two types of zirconia on cross-linked polyethylene and stainless steel on highly cross-linked polyethylene, there was a significant decrease in wear between the polyethylenes and a slight difference between the types of zirconia.
One paper which looked at 102 cementless hips; 51 in each group, zirconia versus chrome cobalt; 6.7 years and they found no difference between these two.
So, wear, we can argue, may not be as significant an issue, but what about tribocorrosion, which is now a pretty significant challenge. We’re all talking about it. It’s been reported anywhere from 1.1 to 4.3% metal-on-polyethylene versus 12% metal-on-metal.
Looking at actual material loss in a retrieval analysis (Kocagoz, CORR, 2016)—50 ceramic and 50 metal—and there was a lot more material loss with metal, both on the stem and, obviously, in the femoral head than with the ceramic.
And then look at chrome cobalt…chromium cobalt release (White, J Arthroplasty, 2016). Comparing 30 patients in each group demonstrated that 57% had elevated cobalt with the metal heads on polyethylene. Seven of them had received MRI, 4 cases of adverse reaction to metal debris where there is none in the ceramic.