Abstract
Highly crosslinked polyethylene (HXLPE) has been used with great clinical success in total hip arthroplasty (THA) since its debut in the late 1990's. However, reports regarding this bearing couple in its second decade of service are still scant. The aim of this study was to 1. Determine the long term clinical and radiological results and 2. Investigate what factors affect wear rates using a metal-on-HXLPE bearing articulation.
55 THA's using a single brand of HXLPE liner, cementless cup and 28mm hip ball were performed in 44 patients. Age, sex, and Charlson Comorbidity Index (CCI) and need for revision surgery were recorded. Linear and volumetric wear was determined using the Martell method.
Mean age at operation was 51.2 (29–73 +/− 12.1) years. Mean duration of follow up was 16.9 years (range 15.0–20.1 +/− 1.1 years). Osteolysis was not present in the latest follow up radiographs.
Median linear and volumetric wear rate was 0.035mm/year (95% CI 0.031–0.047) and 7.12mm3/year (95% CI 6.92–17.25) respectively. Acetabular component position was not found to be related to both linear and volumetric wear. No significant difference was found in the linear and volumetric wear rates of thinner and thicker liners (8mm or below and > 8mm) (p=0.827 and p=0.843 respectively).
HXLPE is associated with very low linear and volumetric wear rates which has virtually obviated osteolysis and has translated to excellent survivorship even at long term follow up. In-vivo oxidation does not appear to be of clinical concern at this point in its service cycle.
