Effect of polyethylene wear on osteolysis in cementless primary total hip arthroplasty - Minimal 5-year follow-up study

We measured polyethylene wear radiographically in 85 cementless primary tot al hip arthroplasties. All patients were followed up for at least 5 years ( mean, 6.3 years). The mean extent of linear wear was 0.88 mm, and the mean rate of linear wear was 0.14 mm/y. The mean volumetric wear was 539.42 mm(3 ), and the mean rate of volumetric wear was 87.69 mm(3)/y. Polyethylene wea r was correlated inversely with the patients' age only and was not influenc ed by other clinical factors. Osteolysis developed in 34 femurs and in ii a cetabula. Radiographic loosening was found in 2 cases in the femur and none in the acetabulum. Polyethylene wear was significantly correlated with fre quency and size of osteolytic lesions. Therefore, polyethylene wear was con sidered one of the major causes of osteolysis, but it was not directly asso ciated with prosthesis loosening. To reduce the extent of polyethylene wear , the material characteristics of polyethylene should be improved, or more durable articulating materials should he developed.