title: Head penetration into Hylamer acetabular liner sterilized by gamma irradiation in air and in a nitrogen atmosphere.
abstract: We reviewed 25 consecutive primary cementless total hip arthroplasties with Hylamer acetabular liners (Hylamer group) and 12 with conventional ultra-high molecular weight polyethylene (Enduron group). Two-dimensional penetration of the femoral head into the liner was determined from anteroposterior radiographs of the pelvis. Head penetration rate was 0.37 mm/y in the Hylamer group sterilized by gamma irradiation in air (n = 6; mean length of follow-up, 3 years), 0.21 mm/y in the Hylamer group sterilized by gamma irradiation in a nitrogen atmosphere (n = 19; mean length of follow-up, 2.7 years), and 0.11 mm/y in the Enduron group (n = 12; mean length of follow-up, 3.9 years). Osteolysis was identified in 6 of the 25 hips with Hylamer liners and 1 of the 12 hips with conventional liners. There was a positive linear correlation between period from production to operation and head penetration rate with Hylamer liner sterilized by gamma irradiation in air and no correlation in a nitrogen atmosphere. Rapid oxidation by irradiation in air might not be the main cause of high rate of wear in Hylamer liners.
authors.affiliation: Department of Orthopaedic Surgery, Nagoya University School of Medicine, Nagoya City, Japan. HIP-KEN@med.nagoya-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Y
authors.initials: Y
authors.lastname: Hasegawa
authors.forename: S
authors.initials: S
authors.lastname: Iwasada
authors.forename: S
authors.initials: S
authors.lastname: Sakano
authors.forename: S
authors.initials: S
authors.lastname: Kitamura
authors.forename: H
authors.initials: H
authors.lastname: Warashina
authors.forename: H
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000077:Acetabulum; D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D005260:Female; D005720:Gamma Rays; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009584:Nitrogen; D011095:Polyethylenes; D012189:Retrospective Studies; D013242:Sterilization
chemical_list: D011095:Polyethylenes; D009584:Nitrogen