Excellent 20-Year Survivorship for Highly Cross-Linked Compared to Conventional Polyethylene in Total Hip Arthroplasty.

Abstract

Highly cross-linked polyethylene (HXLPE) liners have demonstrated excellent wear resistance in total hip arthroplasty (THA). However, there are limited long-term data directly comparing outcomes between HXLPE and conventional polyethylene (CPE) liners. This study compared the 20-year implant survivorship and clinical outcomes after THA with HXLPE versus CPE liners. A retrospective review was performed for patients <65 years who underwent a primary THA at our institution between January 2000 and December 2003, using a CPE or HXLPE liner and a 28-mm cobalt-chromium femoral head. Overall, 331 hips in 282 patients were included: 214 HXLPE and 117 CPE. The mean age, body mass index, and follow-up were 59 years, 31, and 18 years in the CPE group and 53 years, 31, and 17 years in the HXLPE group, respectively. At 20 years, survivorship free from all-cause revision was 94% for HXLPE and 65% for CPE; survivorship free from polyethylene wear-related revision was 100% for HXLPE and 77% for CPE. The HXLPE group had a significantly lower hazard of all-cause revision compared to CPE (hazard ratio = 0.184, P < 0.001), indicating patients who received CPE were five times more likely to undergo revision. No polyethylene wear-related revisions occurred in the HXLPE group, corresponding to a significantly lower risk compared to CPE (hazard ratio = 0.006, P = 0.014). The mean linear wear was significantly lower with HXLPE (0.029 versus 0.24 mm/year, P = 0.007). At final follow-up, both the Harris Hip Score (HXLPE: 89 versus CPE: 91.5) and the Western Ontario and McMaster Universities Osteoarthritis Index (HXLPE: 71.3 versus CPE: 75.4) did not differ significantly. At 20-year follow-up, HXLPE had significantly improved survivorship compared to CPE, with no wear-related revisions in the HXLPE group. These findings support the long-term durability of HXLPE in THA.