Conclusions Current published evidence does not support survivorship differences among commonly used bearing surfaces in patients younger than age 65 years undergoing THA at short- to mid-term followup .
Background  Total hip arthroplasty ( THA )  is increasingly being performed in patients with long life expectancies and active lifestyles .
Newer implant bearing surfaces , with superior wear characteristics , often are used in this cohort with the goal of improving longevity of the prosthesis , but comparisons across the numerous available bearing surfaces are limited , so the surgeon and patient may have difficulty deciding which implants to use .
Questions / purpose sThe purpose of this study was to answer the following question : Is there a short- to mid-term survivorship difference between common THA bearings used in patients younger than age 65 years ?
Cross-linked Compared with Historical Polyethylene in THA: An 8-year Clinical Study
Abstract Wear particle-induced osteolysis is a major cause of aseptic loosening in THA . Increasing wear resistance of polyethylene ( PE ) occurs by increasing the cross-link density and early reports document low wear rates with such implants . To confirm longer-term reductions in wear we compared cross-linked polyethylene ( irradiation in nitrogen , annealing ) with historical polyethylene ( irradiation in air ) in a prospect i ve , r and omized clinical study involving 48 patients who underwent THAs with a minimum followup of 7 years ( mean , 8 years ; range , 7–9 years ) . The insert material was the only variable . The Harris hip score , radiographic signs of osteolysis , and polyethylene wear were recorded annually . Twenty-three historical and 17 moderately cross-linked polyethylene inserts were analyzed ( five patients died , three were lost to followup ) . At 8 years , the wear rate was lower for cross-linked polyethylene ( 0.088 ± 0.03 mm/year ) than for the historical polyethylene ( 0.142 ± 0.07 mm/year ) . This reduction ( 38 % ) did not diminish with time ( 33 % at 5 years ) . Acetabular cyst formation was less frequent ( 39 % versus 12 % ) , affected fewer DeLee and Charnley zones ( 17 % versus 4 % ) , and was less severe for the cross-linked polyethylene . The only revision was for an aseptically loose cup in the historical polyethylene group . Moderately cross-linked polyethylene maintained its wear advantage with time and produced less osteolysis , showing no signs of aging at mid-term followup . Level of Evidence : Level I , therapeutic study . See Guidelines for Authors for a complete description of levels of evidence
Conclusions Current published evidence does not support survivorship differences among commonly used bearing surfaces in patients younger than age 65 years undergoing THA at short- to mid-term followup .
Background  Total hip arthroplasty ( THA )  is increasingly being performed in patients with long life expectancies and active lifestyles .
Newer implant bearing surfaces , with superior wear characteristics , often are used in this cohort with the goal of improving longevity of the prosthesis , but comparisons across the numerous available bearing surfaces are limited , so the surgeon and patient may have difficulty deciding which implants to use .
Questions / purpose sThe purpose of this study was to answer the following question : Is there a short- to mid-term survivorship difference between common THA bearings used in patients younger than age 65 years ?