title: Independent contribution of elevated-rim acetabular liner and femoral head size to the stability of total hip implants.
abstract: The use of an elevated-rim acetabular liner in total hip arthroplasty is widely accepted. We sought to determine quantitatively the amount of additional stability provided by the elevated-rim liner compared with the standard nonelevated liner. The stability of the hip with a 32-mm femoral head was compared with the standard 28-mm head. Our results show that a 15 degrees elevated-rim acetabular liner placed in the posterior quadrant increased hip stability by an additional 8.9 degrees of internal rotation. Similarly the 32-mm head provided 8.1 degrees of additional internal rotation. The increases were statistically significant (P<.0001). We did not encounter increased anterior dislocation intraoperatively. The findings of this study indicate that the 32-mm head may contribute to hip stability in primary total hip arthroplasty, and in instances in which a posterior approach is used, an elevated-rim liner placed in the posterior quadrant may contribute independently to hip stability.
authors.affiliation: Department of Orthopaedic Surgery, The Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: P G
authors.initials: PG
authors.lastname: Sultan
authors.forename: V
authors.initials: V
authors.lastname: Tan
authors.forename: M
authors.initials: M
authors.lastname: Lai
authors.forename: J P
authors.initials: JP
authors.lastname: Garino
mesh_terms: D000077:Acetabulum; D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D005260:Female; D005270:Femur Head; D006617:Hip Dislocation / Q000517:prevention & control*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016896:Treatment Outcome