Similar head wear penetration detected for vitamin-E diffused, crosslinked polyethylene
LISBON, Portugal — Although some creep occurred in vitamin-E diffused polyethylene liners used for total hip arthroplasty in patients with osteoarthritis during the first 6 to 12 months after implantation, results of a radiostereometric analysis presented here showed the liners were associated with no less head penetration at 5-year follow-up than highly crosslinked polyethylene liners.
Kristian Kjaergaard, PhD , presented the study, which won the Best Paper-Orthopaedic Silver Award at the EFORT Annual Congress. He said acetabular cup liners are an area of interest because aseptic loosening of THAs is associated with increased wear of polyethylene liners and it is thought that liner wear may be reduced with the use of vitamin-E diffused liners, which are oxidatively stabilized.
Kjaergaard and his colleagues stratified THA results after 5 years by type of liner and metal femoral head size for 94 patients aged 40 to 70 years who underwent THA. The patients were randomized into four groups. There was one group each for each of the two types of polyethylene liner used and one each for patients who had a 32-mm or 36-mm diameter femoral head implanted.
“The conclusion to this is that there is no difference between vitamin E-diffused polyethylene liners and crosslinked polyethylene liners, or between 32- or 36-mm heads in this 5-year follow-up period,” Kjaergaard said.
The investigators also did not see any significant difference between the groups at 2 years, according to Kjaersgaard, who noted the four groups had similar characteristics at baseline.
“We have creep here in the first 6 to 12 months and then continued wear after that,” he said.
Results showed that for the secondary study outcome of cup migration, there was also no difference seen between the groups at 5 years.
According to the abstract, none of the patients included in the study underwent revision THA during the time they participated in the trial. – by Susan M. Rapp
Kjaergaard K. Abstract 1059. Presented at: EFORT Annual Congress; June 5-7, 2019; Lisbon, Portugal.
Disclosures: The study was sponsored by Zimmer Biomet and Massachusetts General Hospital. Healio.com/Orthopaedics was unable to determine Kjaergaard’s relevant financial disclosures.