Characterization of UHMWPE wear debris in synovial fluids of patients with total knee replacements

The characterization of ultrahigh molecular weight polyethylenes (UHMWPE) particles retrieved from the synovial fluid of knee joints of patients with failed replacements which are present and their frequency of occurrence are studied. The retrieved particles vary in shape and size and are broken down into three categories: globular, fiberous, and flakes. Results show that the three types of particles analyzed from the seven samples are consistent in morphology, size and shape regardless of length of duration of implant and stresses applied. All three types of particles play different roles in macrophage stimulation and activation of cells and biochemicals which leads to osteolysis and aseptic loosening.