Wear and Diagnostic Analysis of Clinical Failures of Artificial Hip Joints

Wear is an important factor in the life of artificial joint prosthesis. This chapter mainly describes the wear mechanism of artificial hip joints, the definition of wear life criteria, causes of abnormal wear, and clinical manifestations of wear failure and establishes an analytical procedure for assessing failure incidents. The clinical manifestations of the wear failure are classified through a wear-osteolysis morphological matrix. The procedure for assessing failure causes is established through a clinical investigation. Nine types of clinical manifestations of wear failure were found. Primary wear processes in artificial hip joints include boundary and mixed friction, adhesive, ploughing, and third-body (abrasive) wear. Surface quality, fit clearance between the acetabular cup and the femoral head, and roundness greatly affect the early abnormal wear. The diversity of clinical manifestations of wear failure is the morphological result of mechanical wear and osteolysis, which is helpful for assessing failure incidents.