A prosthetic device may comprise an insert having a first surface configured to contact a first prosthetic component and a bearing surface configured to articulate against a second prosthetic component. The insert comprises an ultra-high molecular weight polyethylene and vitamin E. The vitamin E may have a concentration in the range of.02 to.12 wt% first mixed with the ultra-high molecular weight polyethylene and then molded with the ultra-high molecular weight polyethylene at a temperature greater than the melting point of the ultra-high molecular weight polyethylene. The ultra-high molecular weight polyethylene and vitamin E may be gamma irradiated with a dosage of radiation between 5 and 20 Mrad. The insert may be machined prior to gamma irradiating the insert in air such that the gamma irradiation, at suitably high dosages, may also sterilize the insert.