title: Biological impact of polyacetal particles on loosening of isoelastic stems.
abstract: 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.
authors.affiliation: Department of Orthopaedic Surgery, University Medical Centre Ljubljana, Zaloska 9, 1000 Ljubljana, Slovenia. klemenstrazar@yahoo.com
authors.forename: Klemen
authors.initials: K
authors.lastname: Strazar
authors.forename: Andrej
authors.initials: A
authors.lastname: Cör
authors.forename: Vane
authors.initials: V
authors.lastname: Antolic
mesh_terms: D000080:Acetals / Q000737:chemistry*; D000368:Aged; D001391:Azo Compounds / Q000494:pharmacology; D001696:Biomechanical Phenomena; D004548:Elasticity; D005260:Female; D005269:Femur / Q000473:pathology; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D009336:Necrosis; D011095:Polyethylenes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011474:Prosthesis Design
chemical_list: D000080:Acetals; D001391:Azo Compounds; D011095:Polyethylenes; D011108:Polymers; C016067:polyacetal; C011049:oil red O