Highly crosslinked polyethylene reduces wear in total hip arthroplasty at 5 years

Abstract

Background: Although hip arthroplasty reliably relieves pain and improves function, problems have arisen with wear and osteolysis. Highly crosslinked polyethylene has been developed to address this problem although at present there is limited clinical evidence it does so longer term.

Questions/purposes: We compared the in vivo wear of standard versus highly crosslinked polyethylene (HXLP) in primary total hip arthroplasty at a minimum of 5-year followup.

Methods: We enrolled 122 patients in a prospective, double-blinded, randomized trial and followed them annually to assess their progress. Annual radiographs were analyzed using previously validated edge detection software to assess for two-dimensional, three-dimensional, and volumetric wear. The mean follow up was 5.5 years (range, 4.1 to 7 years).

Results: The two-dimensional wear measurements for HXLP showed lower wear compared to the conventional group (0.05 mm/year versus 0.26 mm/year, respectively). Three-dimensional and volumetric wear were similarly lower in the HXLP group.

Conclusions: Highly crosslinked polyethylene undergoes substantially less wear than conventional polyethylene at medium term. The effect of hip arthroplasty longevity will need to be assessed with longer-term studies, but this may lead to a decreased need for revision as a result of less wear and osteolysis.

Fig. 1

The graph shows reduced two-dimensional wear with time of highly versus standard crosslinked polyethylene.

Fig. 2

The graph shows reduced three-dimensional wear with time of highly versus standard crosslinked polyethylene.

Fig. 3

Volumetric wear with time (standard versus highly crosslinked polyethylene) is shown in this graph.