Large wear rate reductions have been shown for crosslinked PE in simulators and short- to mid-term clinical wear studies. However, concerns persist about long-term in-vivo oxidation (especially with annealed PE), late accelerating wear and the possibly higher osteolytic potential of crosslinked PE particle debris. This is the first long-term study comparing conventional to crosslinked PE investigating whether the wear reduction is maintained in the long-term and if reduced osteolysis becomes evident. In a prospective study 48 primary THA patients (Stryker ABG-II, 28mm CoCr heads) were randomized to either receive a first generation crosslinked PE (Stryker Duration: 3MRad gamma irradiation in N2, annealed) or then conventional, now “historic” PE (3MRad gamma irradiation in air). Both groups were statistically non-different (p>0.1) regarding age (63.9 years), gender, BMI, stem and cup size, cup inclination, liner thickness or pre- and post-op HHS leaving the insert material as the only variable. Patients were followed-up annually using the Harris Hip score, AP and lateral radiographs and digital wear measurements using Roman V1.70 [1, 2]. Wear and radiographic signs of osteolysis were analysed at a mean follow-up of 12.9 years (12.0–13.3). Groups were compared using the t-test (means) or the Fisher Exact test (proportions).Introduction
Materials & Methods
