Medical-grade Ultra-high Molecular Weight Polyethylene: Past, Current, and Future

Ultra-high molecular weight polyethylene is a semi-crystalline polymer (45–60%) with six decades of orthopaedic applications. This polymer has a high fracture toughness (30 kJ m ⁻²) which comes from the molecular weight and the chain entanglements. Adverse alteration of the properties may lead to the part's pre-mature failure. This paper reviews the current manufacturing methods, and their effect on the properties of the polymer. The review also focused on the attempts of enhancing the polymer properties. The main cause of failure is implant loosing owing to the polymeric wear particles. Many manufacturers have attempted to enhance the wear and oxidation properties of the polymer, and the outcome of the new technologies is critically reviewed. Finally, the review explores the potential for future developments. This review was submitted as part of the 2018 Materials Literature Review Prize of the Institute of Materials, Minerals and Mining run by the Editorial Board of MST. Sponsorship of the prize by TWI Ltd is gratefully acknowledged.