Randomised controlled trials (RCTs) that compared highly cross-linked polyethylene with conventional polyethylene in total hip arthroplasty were eligible for inclusion.
Included studies assessed four highly cross-linked polyethylene liners (Marathon, Longevity, Durasul and Crossfire). Controls were Enduron, Sulene and conventional polyethylene. Types of hip implant and fixation methods varied and included hybrid, cemented and cementless. Outcomes assessed included rates of wear and penetration. Studies used different parameters to measure outcomes including linear, 2D linear, volumetric, 2D and 3D volumetric and volumetric for wear rate and proximal, total, medial, anterior linear and volumetric head for penetration.
One reviewer initially screened studies based on title and abstract information; two reviewers then independently selected studies for inclusion based on full-text articles. Disagreements were resolved by discussion.