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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.