Mechanical Failure of Marathon Cross-Linked Polyethylene Acetabular Liner After Total Hip Arthroplasty

摘要

Polyethylene wear and resultant particulate debris can lead to failure through osteolysis, late loosening, instability in total hip arthroplasty (THA), and other modes. Cross-linked polyethylene was developed as a potential solution to the problems created by wear. The increased resistance to adhesive and abrasive wear with this bearing surface has been well documented in laboratory hip simulator studies. Early results of in vivo clinical studies also have shown the decreased wear advantage of cross-linked polyethylene. The major disadvantage of cross-linking is its deleterious effect on mechanical properties, such as fracture toughness, fatigue resistance, and resistance to crack propagation. Indeed, extensive surface cracks were found in Durasul (Sulzer Orthopaedics, Austin, Texas) highly cross-linked acetabular retrievals. These defects were thought to be caused by a decrease in the mechanical properties of the polyethylene. These liners had not failed clinically; they were revised for reasons other than mechanical failure. However, such reduction in mechanical properties can lead to catastrophic large-scale polyethylene failure, particularly in weight-bearing joint arthroplasty.