Abstract
Purpose
The objective of this study was to compare the wear characteristics and damage scores in highly crosslinked (XLPE) and conventional polyethylene (CPE) acetabular liners.
Methods
This was a retrieval analysis of 13 XLPE liners obtained from patients who underwent revision surgery from 1999 to 2011. These patients were matched on patient demographics (age, BMI, side, sex, and length of implantation) and implant characteristics (inner diameter, outer diameter, and lip angle) to another group with CPE who underwent revision in the same time period. The only difference between implants was the use of XLPE. Wear analysis was performed with micro-computed tomography (micro-CT), provided thickness measurements across four quadrants of the bearing surface. Surface damage was scored and the pattern documented. The mean duration of implantation was 5.00 ± 3.36 years in the XLPE group and 5.19 ± 3.69 years in the CPE group (p = 0.12), with the longest duration exceeding 10 years.
Results
CPE demonstrated more wear at time of retrieval with a mean thickness of 8.18 ± 1.50 mm compared to XLPE with a mean thickness of 8.91 ± 1.76 mm (p < 0.001). Damage scoring was not significantly different between the two groups, with a total damage score of 13.77 ± 3.95 in XLPE and 15.23 ± 4.63 in CPE (p = 0.18). There was no difference in the distribution of wear and damage.
Conclusion
XLPE undergoes less wear than CPE, however this may not be apparent by using damage scoring alone, which is the most common retrieval analysis technique. The superior wear properties of XLPE may reduce the need for revision surgery as a result of decreased wear and osteolysis.
