Hylamer wear rates and shelf life: a clinical correlation

We evaluated the performance of 84 Hylamer polyethylene components and zirconia modular femoral heads which were implanted in a single institution over a 5 year period. Patients were followed up for a mean of 6.2 years. The mean rate of penetration was 0.58 mm/year (0.05-1.0). Lot/batch numbers were available in the clinical case notes of 54 patients. Using the lot/batch numbers, we were able to determine the Hylamer cups' shelf lifes. We found that liners with a shelf life greater than 10 months had a significantly greater linear wear (0.38 mm/year) than those implanted in less than 10 months (0.05 mm/year).