Methods of chemically cross-linking antioxidant-stabilized polymeric material are provided. In one example embodiment, peroxide cross-linking can be used to improve wear resistance and the addition of antioxidant can be used to improve oxidation resistance of ultra-high molecular weight polyethylene. A balance between the amounts of peroxide(s) and antioxidant(s) in the polymeric material can ensure that enough cross-linking is achieved for wear reduction and that enough antioxidant is incorporated for improved long-term oxidative stability. In one example embodiment, peroxide(s) can be diffused into a consolidated polymeric material for cross-linking. In another embodiment, polymeric material is consolidated with a vinyl silane, an antioxidant, and a free radical initiator, and the consolidated polymeric material is contacted with water thereby forming an oxidation resistant, cross-linked polymeric material. Such materials can be used in orthopedic applications such as bearing surfaces in total joint implants, including total hips, total knees, total shoulders, and other total joints.
