UHMWPE Biomaterials Handbook

Ultra High Molecular Weight Polyethylene in Total Joint Replacement and Medical Devices

Steven M. Kurtz

• Editore: William Andrew
• Anno: 2015
• ISBN:
  9780323354356
• Edizione: 3
• Argomento: Technologie et ingénierie
• Categoria: Science des matériaux

UHMWPE Biomaterials Handbook, Third Edition, describes the science, development, properties, and application of ultra-high molecular weight polyethylene (UHMWPE) used in artificial joints. UHMWPE is now the material of choice for joint replacements, and is increasingly being used in fibers for sutures. This book is a one-stop reference for information on this advanced material, covering both introductory topics and the most advanced developments.

The third edition adds six new chapters on a range of topics, including the latest in anti-oxidant technologies for stabilizing HXLPE and up-to-date systematic reviews of the clinical literature for HXLPE in hips and knees. The book chronicles the rise and fall of all-metal hip implants, as well as the increased use of ceramic biomaterials and UHMWPE for this application. This book also brings orthopedic researchers and practitioners up to date on the stabilization of UHMWPE with antioxidants, as well as the choices of antioxidant available for practitioners.

The book also thoroughly assesses the clinical performance of HXLPE, as well as alternative bearings in knee replacement and UHMWPE articulations with polyether ether ketone (PEEK).

Written and edited by the top experts in the field of UHMWPE, this is the only state-of-the-art reference for professionals, researchers, and clinicians working with this material.

• The only complete reference for professionals, researchers, and clinicians working with ultra-high molecular weight polyethylene biomaterials technologies for joint replacement and implants
• New edition includes six new chapters on a wide range of topics, including the clinical performance of highly crosslinked polyethylene (HXLPE) in hip and knee replacement, an overview of antioxidant stabilization for UHMWPE, and the medical applications of UHMWPE fibers
• State-of-the-art coverage of the latest UHMWPE technology, orthopedic applications, biomaterial characterization, and engineering aspects from recognized leaders in the field

1

A Primer on UHMWPE

Steven M. Kurtz PhD Exponent, Inc.; Drexel University, Philadelphia, PA, USA

Abstract

Ultra-high molecular weight polyethylene (UHMWPE) is a unique polymer with outstanding physical and mechanical properties. Most notable are its chemical inertness, lubricity, impact resistance, and abrasion resistance. These characteristics of UHMWPE have been exploited since the 1950s in a wide range of industrial applications, including pickers for textile machinery, lining for coal chutes and dump trucks, runners for bottling production lines, as well as bumpers and siding for ships and harbors. Over 90% of the UHMWPE produced in the world is used by industry.

Keywords

polymer

polyethylene

thermal

crystallinity

1.1. Introduction

Ultra-high molecular weight polyethylene (UHMWPE) is a unique polymer with outstanding physical and mechanical properties. Most notable are its chemical inertness, lubricity, impact resistance, and abrasion resistance. These characteristics of UHMWPE have been exploited since the 1950s in a wide range of industrial applications (Figure 1.1), including pickers for textile machinery, lining for coal chutes and dump trucks, runners for bottling production lines, as well as bumpers and siding for ships and harbors. Over 90% of the UHMWPE produced in the world is used by industries.

Figure 1.1 Dump truck liner of UHMWPE, an example of an industrial application for the polymer.

For the past 50 years, UHMWPE has also been used in orthopedics as a bearing material in artificial joints. Each year, about three million joint replacement procedures are performed around the world, and the majority of these joint replacements incorporate UHMWPE. Despite the success of these restorative procedures, orthopedic and spine implants have only a finite lifetime. Wear and damage of the UHMWPE components has historically been one of the factors limiting implant longevity. In the past 15 years, highly cross-linked UHMWPE biomaterials have shown dramatic reductions in wear and improved long-term survivorship in total hip replacements around the world. The orthopedic community awaits confirmation that these reductions in wear will be associated with improved long-term survival in total knee replacements as well.

UHMWPE comes from a family of polymers with a deceptively simple chemical composition, consisting of only hydrogen and carbon. However, the simplicity inherent its chemical composition belies a more complex hierarchy of organizational structures at the molecular and supermolecular length scales. At a molecular level, the carbon backbone of polyethylene can twist, rotate, and fold into ordered crystalline regions. At a supermolecular level, the UHMWPE consists of powder (also known as resin or flake) that must be consolidated at elevated temperatures and pressures to form a bulk material. Further layers of complexity are introduced by chemical changes that arise in UHMWPE due to radiation, sterilization, and processing.

The purpose of this Handbook is to explore the complexities inherent in UHMWPE and an increasingly diverse field of UHMWPE biomaterials that include radiation cross-linking, composites, and antioxidants such as Vitamin E. This book is intended to provide the reader with a background in the terminology, history, and recent advances related to its use in orthopedics. A monograph such as this is helpful in several respects. First, it is important that members of the surgical community have access to up-to-date knowledge about the properties of UHMWPE so that this information can be more accurately communicated to their patients. Second, members of the orthopedic research community need access to timely synthesis of the existing literature so that future studies are more effectively planned to fill in existing gaps in our current understanding. Finally, this handbook may also serve as a resource for university students at both the undergraduate and graduate levels.

This introductory chapter starts with the basics, assuming the reader is not familiar with polymers, let alone polyethylene. The chapter provides basic information about polymers in general, describes the structure and composition of polyethylene, and explains how UHMWPE differs from other polymers (including HDPE) and from other materials (e.g., metals and ceramics). The concepts of crystallinity and thermal transitions are introduced at a basic level. Readers familiar with these basic polymer concepts may want to consider skipping ahead to the next chapter.

1.2. What is a Polymer?

The ultra-high molecular weight polyethylene (UHMWPE) used in orthopedic applications is a type of polymer generally classified as a linear homopolymer. Our first task is to explain what is meant by all of these terms. Before proceeding to a definition of UHMWPE, one needs to first understand what constitutes a linear homopolymer.

A polymer is a molecule consisting of many (poly-) parts (-mer) linked together by chemical covalent bonds. The individual parts, or monomer segments, of a polymer can all ...

Indice dei contenuti

• Cover
• Title page
• Table of Contents
• Copyright
• Dedication
• List of Contributors
• Foreword
• 1: A Primer on UHMWPE
• 2: From Ethylene Gas to UHMWPE Component: The Process of Producing Orthopedic Implants
• 3: Packaging and Sterilization of UHMWPE
• 4: The Origins of UHMWPE in Total Hip Arthroplasty
• 5: The Clinical Performance of Historical and Conventional UHMWPE in Hip Replacements
• 6: The Clinical Performance of Highly Cross-linked UHMWPE in Hip Replacements
• 7: Contemporary Total Hip Arthroplasty: Alternative Bearings
• 8: The Origins and Adaptations of UHMWPE for Knee Replacements
• 9: The Clinical Performance of UHMWPE in Knee Replacements
• 10: Contemporary Total Knee Arthroplasty: Alternative Bearings
• 11: The Clinical Performance of UHMWPE in Shoulder Replacements
• 12: The Clinical Performance of UHMWPE in Elbow Replacements
• 13: Applications of UHMWPE in Total Ankle Replacements
• 14: The Clinical Performance of UHMWPE in the Spine
• 15: Highly Cross-Linked and Melted UHMWPE
• 16: Highly Cross-Linked and Annealed UHMWPE
• 17: Vitamin E-Blended UHMWPE Biomaterials
• 18: Highly Cross-Linked UHMWPE Doped with Vitamin E
• 19: Alternate Antioxidants for Orthopedic Devices
• 20: Phospholipid Polymer Grafted Highly Cross-Linked UHMWPE
• 21: UHMWPE Matrix Composites
• 22: UHMWPE Homocomposites and Fibers
• 23: UHMWPE–Hyaluronan Microcomposite Biomaterials
• 24: High Pressure Crystallized UHMWPEs
• 25: Compendium of HXLPEs
• 26: Mechanisms of Cross-Linking, Oxidative Degradation, and Stabilization of UHMWPE
• 27: In Vivo Oxidation of UHMWPE
• 28: Pathophysiologic Reactions to UHMWPE Wear Particles
• 29: Characterization of Physical, Chemical, and Mechanical Properties of UHMWPE
• 30: Wear Assessment of UHMWPE with Pin-on-Disc Testing
• 31: Tribology of UHMWPE in the Hip
• 32: Tribological Assessment of UHMWPE in the Knee
• 33: Characterization of UHMWPE Wear Particles
• 34: Clinical Surveillance of UHMWPE Using Radiographic Methods
• 35: ESR Insights into Macroradicals in UHMWPE
• 36: Fatigue and Fracture of UHMWPE
• 37: Development and Application of the Notched Tensile Test to UHMWPE
• 38: Development and Application of the Small Punch Test to UHMWPE
• 39: Computer Modeling and Simulation of UHMWPE
• 40: Nano- and Microindentation Testing of UHMWPE
• 41: MicroCT Analysis of Wear and Damage in UHMWPE
• Subject Index