No Revisions Attributable to Wear of Highly Cross-Linked Polyethylene Liners: A Long-Term Follow-Up Study.

ABSTRACT

BACKGROUND: There is a paucity of data beyond 15 years on the survivorship of total hip arthroplasty since the introduction of highly cross-linked polyethylene (HXLPE) liners. Our aim was to evaluate implant survivorship, liner wear rates, and clinical outcomes after primary total hip arthroplasty using HXLPE liners implanted between 1999 and 2002. METHODS: Between 1999 and 2002, 690 primary total hip arthroplasties utilizing 28-mm femoral heads and HXLPE liners of a single design were identified using our institutional total joint registry. Femoral heads were made of metal in 96% of cases and ceramic in 4%. The mean age was 56 years, 48% were women, and the mean body mass index was 30. Survivorship analyses were performed for the outcomes of implant revision, reoperation, and complications for the entire cohort. Linear HXLPE liner wear rates were determined on 197 hips with radiographs with more than 18.5 years of follow-up. RESULTS: At 20 years, survivorship free of revision was 94%, free of reoperation was 92%, and free of any complication was 81%. There were no documented wear-related revisions. The linear wear rate at a mean of 20.3 years postoperatively was 0.02 mm/y. There was no statistically significant difference in measured wear observed between the first available postoperative radiographs and those taken at the final follow-up. The use of elevated liners, patient body mass index, age, preoperative diagnosis, acetabular component inclination, and anteversion angles were not associated with increased wear rates. Mean Harris hip scores improved from 52 preoperatively to 90 at greater than 18.5 years CONCLUSIONS: Primary total hip arthroplasties using a single first-generation HXLPE liner demonstrated excellent survivorship and clinical outcomes at long-term follow-up with no wear-related revisions. Wear rates of HXLPE liners at 20 years are exceedingly low and are not significantly impacted by acetabular component position or patient-dependent variables such as BMI. LEVEL OF EVIDENCE IV.