Modular acetabular systems have several advantages; however, increased polyethylene 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). 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 followup. The true linear wear rate was 0.173 mm/year (range 0.03-0.423). 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.
About the HSS Journal
HSS Journal, an academic peer-reviewed journal, is published twice a year, February and September, and features articles by internal faculty and HSS alumni that present current research and clinical work in the field of musculoskeletal medicine performed at HSS, including research articles, surgical procedures, and case reports.