The aim of our study was to identify
biological factors responsible for premature loosening of
polyacetal hip stems. The results of histological analyses of the tissue around 11 total
hip prostheses with loosened
polyacetal femoral stems were compared to those obtained in a group of 11 total
hip prostheses with loosened
metal (CoCr) femoral components. A higher number of
polymer wear particles surrounded by giant cells, more bone chips, and a more extensive
necrosis were found around loosened
polyacetal stems. Histomorphological characteristics of
polyacetal wear particles containing BaSO(4) granules in the tissue around loosened
polyacetal stems were described. Radiological evaluation of the wear of
polyethylene cups suggested that elastic modulus of the stem had no influence on the wear of
polyethylene cups. This study indicates that
polyacetal wear particles have a great
biological potential accelerating the process of loosening.