Evolution of UHMWPE: Do We Need Antioxidants?

Abstract

Periprosthetic osteolysis is primarily caused by particulate debris created through wear of UHMWPE components used in total joint arthroplasty [15], resulting in bone resorption around implants and in most cases leading to revision surgery (Fig. 18.1). Osteolysis was a major problem until the advancement of highly cross-linked UHMWPEs in the mid-1990s. The clinical use of highly cross-linked UHMWPE in total hips has been tried as early as the 1970s by a number of clinicians in the United Kingdom [2, 3], in South Africa [12, 14], and in Japan [27–29]. The success of these early, experimental highly cross-linked UHMWPE formulations was not appreciated until much later when the long-term clinical follow-up data became available [45]; therefore, the widespread clinical use of these experimental formulations did not materialize. In the mid-1990s, with the growing concern of periprosthetic osteolysis, combined research efforts of many centers around the world resulted in the development of the more contemporary, first-generation highly cross-linked UHMWPE formulations [22, 25]. These efforts were greatly helped by the more sophisticated understanding of the interplay between kinematics and wear of the load-bearing surfaces [6] and adverse effects of trapped free radicals on oxidative stability of gamma-sterilized UHMWPE components [8]. The more clinically relevant hip and knee simulator wear testing was instrumental in preclinical testing. Accelerated aging was also used to better understand potential material changes in the long term.