title: Standing versus supine radiographs to evaluate femoral head penetration in the polyethylene liner after total hip arthroplasty.
abstract: The linear penetration rates for ceramic femoral heads on conventional and highly cross-linked polyethylene were measured and compared with radiographs taken in the standing and supine position taken three weeks postoperatively and at final follow-up. Seventy-five patients (83 hips) with conventional polyethylene (group-1) and two hundred and seventy five patients (300 hips) with highly cross-linked polyethylene (group-2) were studied. Follow-up periods were 14.5years in group-1 and 8.6years in group-2. The average penetration rates in group-1 were 0.17mm/year in supine position and 0.18mm/year in standing position (P<0.05). On the other hand, the rates in group-2 were 0.03mm/year and 0.04mm/year respectively (P<0.05). Although there were statistical differences between groups, 0.01mm differences are probably not clinically relevant.
authors.affiliation: Department of Orthopedic Surgery, Shinonoi General Hospital, Shinonoi, Nagano 388-8004, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Maruyama
authors.affiliation: Department of Orthopedic Surgery, Shinshu University School of Medicine, Matsumoto, Nagano 390-8621, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Tensho
authors.affiliation: Department of Orthopedic Surgery, Chushin Matsumoto Hospital, Matsumoto Medical Center, Matsumoto, Nagano 399-0021, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Wakabayashi
authors.affiliation: Department of Orthopedic Surgery, IMS Miyoshi General Hospital, Miyoshi-cho, Iruma-gun Saitama 354-0041, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hisa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001672:Biocompatible Materials; D002516:Ceramics; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging* / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011187:Posture; D011475:Prosthesis Failure; D011859:Radiography; D055815:Young Adult
chemical_list: D001672:Biocompatible Materials; D020959:Polyethylene
keywords: femoral head penetration; polyethylene liner wear; standing radiograph; total hip arthroplasty