A team of Mayo Clinic researchers set out to examine the durability of new liners that are placed into a well-fixed acetabular component during revision total hip arthroplasty (THA). Their work, “Intermediate to Long-Term Follow-up of Cementing Liners into Well-Fixed Acetabular Components,” was published in the June 24, 2020 edition of The Journal of Bone and Joint Surgery.
The researchers, at Mayo Clinic in Rochester, Minnesota, identified 323 revision THAs where a nonconstrained highly cross-linked polyethylene (HXLPE) liner was cemented into a well-fixed acetabular component. Reasons for revision included polyethylene wear and osteolysis (48%), aseptic femoral loosening (35%), and hip instability (8%); mean followup was nine years.
As for why this topic hasn’t been widely addressed in the literature, Dr. Berry explained to OTW, “This technique has been used widely by surgeons during selected revisions. However, few institutions have had a sufficient number of cases with good follow up to allow for a rigorous study of the results. The large Mayo Clinic revision practice, in addition to our excellent total joint registry which allows us to capture and follow all of our joint replacement patients, provided us with the material and tools to perform this study.”
“The most important results of this study were the finding that when a polyethylene liner is cemented into a well-fixed metal-backed cup, the fixation of that liner into the cup can be reliable and durable with a low subsequent rate of failure of the cemented interface between the liner and the cup.”
But that’s not the whole picture, says Dr. Berry.
“An important caveat for readers to be aware of is that indications, implant selection, and the procedural technique are important to obtain these favorable results. The surgeon should strive to use a cross-linked polyethylene liner that can be fully seated into the metal cup, the back surface of the liner should be contoured with a burr so that it has fairly deep grooves for cement interdigitation (we prefer a ‘spider web’ pattern), and the shell itself should have an internal geometry (such as screw holes or grooves) that allows for strong cement interdigitation.”
“The most common circumstances in which this procedure is performed are when a revision is being done in which the surgeon desires to retain a well-fixed uncemented acetabular component that does not have a compatible modern snap-in liner made of cross-linked polyethylene or does not have modern snap-in liner with optimal femoral head diameter or liner configuration (such as an elevated or face changing rim).”
“We will continue to follow these patients for even longer periods of time, but with the follow up currently available the efficacy of the technique, when performed well, seems established.”
