Low longterm wear observed with multiple sized femoral heads using HXLPE in THA

DALLAS — Femoral heads treated with highly cross-linked polyethylene showed low wear during long-term follow-up, according to a presentation made here at the American Association of Hip and Knee Surgeons Annual Meeting.

To measure head penetration into the highly cross-linked polyethylene (HXLPE), investigators studied 16 patients who received a 28-mm head and 13 patients who received a 36-mm head during total hip arthroplasty. CT scan was taken at 13 years postoperatively, and radiostereometric analysis and radiographs were taken at 4 weeks to 6 weeks, 6 months, 1 year, 2 years, 3 years, 4 years, 5 years, 7 years, 10 years and 13 years postoperatively.

Differences in penetration during the study period were measured using a Wilcoxon signed-rank test. The total patient population dwindled during the follow-up to 24 patients at 6 months, 19 patients at 2 years, 17 patients at 3 years, nine patients at 5 years, 10 patients at 10 years and nine patients at 13 years.

Harry E. Rubash

Median standard error steady state wear was 0.07 mm for both patient cohorts. No significant differences were observed in steady state wear either at any time point in the overall patient population or between cohorts.

Results from CT scans for all patients at 13 years postoperatively are currently being evaluated.

“There was no lysis on plain film. There was no lysis on CT scan, and we think [HXLPE] continues to be a highly attractive bearing surface in total hip arthroplasty,” Harry E. Rubash, MD, said in his presentation. - by Christian Ingram

Reference:

Nebergall AK, et al. Paper #24. Presented at: American Association of Hip and Knee Surgeons Annual Meeting. Nov. 6-8, 2015; Dallas.

Disclosure: Rubash that he receives royalties from Ceramtec and Stryker; is a paid consultant for Access Mediquip, Flexion and Pacira; and is a board member of the Hip Society.