Quantitative analysis of polyethylene wear debris, wear rate and head damage in retrieved Charnley hip prostheses

Submicrometer- and micrometer-sized ultra-high molecular weight polyethylen e (UHMWPE) wear particles have been associated with osteolysis and failure of total artificial joints. Previous studies have isolated predominantly su bmicrometer-sized particles at the expense of larger particles (> 10 mu m). This study aimed to isolate and characterize quantitatively all sizes of U HMWPE wear particles generated in 18 Charnley hip prostheses. In addition, to analyze the wear debris with respect to the total volumetric wear of the cup and damage to the femoral head. Particle size distributions ranged fro m 0.1 to - > 1000 mu m. A significant proportion (3-82%) of the mass of the wear debris isolated was > 10 mu m. The mode of the frequency distribution of the particles was in the range 0.1-0.5 mu m for all patients. However, analysis of the mass of wear debris as a function of its size allowed diffe rentiation of the wear debris from different patients. Femoral head damage was associated with high volumetric wear and increased numbers of biologica lly active submicrometer-sized particles. (C) 2000 Kluwer Academic Publishe rs.