title: Comparison of femoral head penetration rates between cementless acetabular components with 22-mm and 28-mm heads.
abstract: Between April 1993 and July 1994, the senior author (R.C.J.) performed 151 consecutive primary total hip arthroplasties using a Harris-Galante II acetabular component and a polished Iowa femoral component. In 105 hips, 22-mm head components were used, and in 46 hips, 28-mm head components were used. Femoral head penetration into the acetabular shell was measured using digital edge detection techniques. The group average penetration for the initial 2-year bedding-in period was 0.35 mm/y for the 22-mm and 0.31 mm/y for the 28-mm head components. The long-term rate of penetration into the shell was 0.11 mm/y for the 22-mm heads and 0.17 mm/y for the 28-mm heads, a significant difference (P=.029). The dislocation rate was significantly higher, however, with the 22-mm heads (P=.001). The 22-mm components showed significantly less wear but at the expense of an increase in the prevalence of dislocation.
authors.affiliation: Department of Orthopaedic Surgery, University of Iowa Health Care, Iowa City, Iowa 52242, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Pedersen
authors.forename: J J
authors.initials: JJ
authors.lastname: Callaghan
authors.forename: T L
authors.initials: TL
authors.lastname: Johnston
authors.forename: G B
authors.initials: GB
authors.lastname: Fetzer
authors.forename: R C
authors.initials: RC
authors.lastname: Johnston
mesh_terms: D000077:Acetabulum / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D005260:Female; D005270:Femur Head / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D018709:Statistics, Nonparametric; D016896:Treatment Outcome