We evaluated the mid-term performance of a moderately cross-linked polyethylene THA bearing in younger patients. One hundred consecutive THAs performed in patients 50years of age and under using the same cementless acetabular component and moderately cross-linked polyethylene were evaluated at minimum 10year follow-up. At final follow-up 75 patients (89 hips) were living, 7 patients (7 hips) were deceased and 4 patients (4 hips) were lost to follow-up. Average Tegner and UCLA scores were 3.7 and 5.8, respectively. Average steps per year were 1.84 million. The average linear wear rate was 0.05mm/y and steady state wear rate was 0.033mm/y. There was no detectable osteolysis. Minimum 10year follow-up demonstrated durable fixation and reduced wear (P<0.001) when compared to our historical controls.