title: Early follow-up for a hybrid total hip arthroplasty using a metal-backed acetabular component designed to reduce "backside" polyethylene wear.
abstract: Modular acetabular systems have several advantages; however, increased polyethylene wear has been recognized as a disadvantage. In our study, an acetabular shell design with a highly polished inner surface, a locking mechanism that minimizes micromotion, and a high polyethylene liner to shell conformity was evaluated. A prospective cohort of 50 consecutive hips was followed up for a mean of 3.6 years (range, 2-7 years). One patient required an early revision for recurrent instability. Mean linear head penetration rates were 0.242 mm/year (range, 0.048-0.655 mm/year). The true linear wear rate was calculated after subtracting the linear wear in the first follow-up year from the total wear at the end of the follow-up. The true linear wear rate was 0.173 mm/year (range, 0.03-0.423 mm/year). A positive correlation was found between wear rate and male gender. The low head penetration rates suggest that a polished liner with an improved locking mechanism and increased liner conformity can reduce polyethylene wear.
authors.affiliation: Shiley Center for Orthopaedic Research and Education at Scripps Clinic, 11025 North Torrey Pines Road, Suite 140, La Jolla, CA 92037, USA.
authors.forename: Colin E
authors.initials: CE
authors.lastname: Poole
authors.forename: Shantanu S
authors.initials: SS
authors.lastname: Patil
authors.forename: Darryl D
authors.initials: DD
authors.lastname: D'Lima
authors.forename: Clifford W
authors.initials: CW
authors.lastname: Colwell