Wear Debris: Ultra High Molecular Weight Polyethylene (UHMWPE) in Total Joint Replacement and Medical Devices

[Justin]

Recent SPS threads have focused on wear debris associated with Artificial Disc Replacement (ADR) devices. The ADR devices that are currently FDA approved and those in clinical trials have designs that feature either a "metal-on-metal" design or have a combination of titanium alloy endplates & a hard plastic core made of ultra high molecular weight polyethylene (UHMWPE).

In my research over the last 7 years, I have had great difficulty in finding peer-reviewed literature on wear debris and artificial discs. However, I recently found a great resource that I would like to share with the SPS member community--the UHMWPE Biomaterials Handbook--the 2nd Edition was just released on June 29, 2009!

The UHMWPE Biomaterials Handbook includes discussion on Chartie (I, II and III), ProDisc-L, Mobidisc, Activ-L, ProDisc-C, PCM, Mobi-C, Activ-C and the Discover devices.

Chapter 12.1 Introduction
Chapter 12.2 The Charité Artificial Disc
Chapter 12.3 Lumbar Disc Arthroplasty
Chapter 12.4 Cervical Disc Arthroplasty
Chapter 12.5 Wear and in vivo Degradation of UHMWPE in the Spine
Chapter 12.6 Alternatives to UHMWPE in Disc Replacement
Chapter 12.7 Many Unanswered Questions Remain
Chapter 12.8 Acknowledgements, References

Click the following link for a preview in Google Books (some pages are missing due to copyright):

UHMWPE Biomaterials Handbook, Second Edition: Ultra High Molecular Weight Polyethylene in Total Joint Replacement and Medical Devices by Steven M Kurtz
--> Chapter 12: The Clinical Performance of UHMWPE in the Spine

UHMWPE Biomaterials Handbook, Second Edition: Ultra High Molecular Weight Polyethylene in Total Joint Replacement and Medical Devices by Steven M Kurtz. Academic Press (Elsevier Science); 2 edition (June 29, 2009), ISBN-13: 9780123747211. Link to Amazon

Synopsis

This book describes the science, development, properties and application of of ultra-high molecular weight polyethylene (UHMWPE) used in artificial joints. This material is currently used in 1.4 million patients around the world every year for use in the hip, knee, upper extremities, and spine.

Since the publication of the 1st edition there have been major advances in the development and clinical adoption of highly crosslinked UHMWPE for hip and knee replacement. There has also been a major international effort to introduce Vitamin E stabilized UHMWPE for patients. The accumulated knowledge on these two classes of materials are a key feature of the 2nd edition, along with an additional 19 additional chapters providing coverage of the key engineering aspects (biomechanical and materials science) and clinical/biological performance of UHMWPE, providing a more complete reference for industrial and academic materials specialists, and for surgeons and clinicians who require an understanding of the biomaterials properties of UHMWPE to work successfully on patient applications.

• The UHMWPE Handbook is the comprehensive reference for professionals, researchers, and clinicians working with biomaterials technologies for joint replacement
• New to this edition: 19 new chapters keep readers up to date with this fast moving topic, including a new section on UHMWPE biomaterials; highly crosslinked UHMWPE for hip and knee replacement; Vitamin E stabilized UHMWPE for patients; clinical performance, tribology an biologic interaction of UHMWPE
• State-of-the-art coverage of UHMWPE technology, orthopedic applications, biomaterial characterisation and engineering aspects fromrecognised leaders in the field

Journal of Bone and Joint Surgery

The UHMWPE Handbook is a comprehensive yet concise presentation of the important role that polyethylene has played and continues to play in the treatment armamentarium of the orthopaedic surgeon. The comprehensiveness of this volume is evidenced by the broad range of topics addressed: from the history of the clinical introduction and clinical performance of ultra-high molecular weight polyethylene in hip and knee arthroplasty to the complexities of polyethylene synthesis and processing, resin nomenclature, material degradation, analytic modeling, biomechanical and structural characterization, and currently available highly cross-linked products. Even though each one of these topics could not be dealt with in great depth, the breadth of the subject matter gives the reader an excellent overview of the field that will stimulate further reading and research. Portions of this book will be of great interest to orthopaedic residents and orthopaedic surgeons, providing them with a basic framework to understand the performance of ultra-high molecular weight polyethylene in a variety of clinical settings, including arthroplasty of the hip, knee, shoulder, and disc. This book should be read by individuals who are involved in clinical and basic research concerning polyethylene performance as well as by biomedical engineering trainees who intend to pursue a career in the orthopaedic device industry. The author and his colleagues are to be commended for compiling this information and producing an authoritative and useful resource for our specialty.—Joshua J. Jacobs, MD, Rush University Medical Center, Chicago, Illinois

Biography

Dr. Kurtz has been researching ultra-high molecular weight polyehtylene(UHMWPE) for use in orthopedics for over 10 years. He has published dozens of papers and several book chapters related to UHMWPE used in joint replacement. He has pioneered the development of new test methods for the material in orthopedics. Dr. Kurtz has authored national and international standards for medical upgrade UHMWPE. As a principle engineer at Exponent, an international engineering and scientific consulting company, his research on UHMWPE is supported by several major orthopedic manufacturers. He has funding from the National Institutes for Health to stdy UHMWPE changes after implanatation in the body, as well as to develop new computer-based tools to predict the performance of new UHMWPE materials. Dr. Kurtz is the Director of an orthopedic implant retrieval program in Philadelphia which is affiliated with Drexel University and Thomas Jefferson University. He teaches classes on the performance of orthopedic polymers (including UHMWPE) at Drexel, Temple, and Princeton Universities.

[Katie]

Thanks for this Justin. Can you tell me if this is connected at all to the polymer being used in the M6?

The Annulus is made of the UHWMPE that you mentioned, but the Sheath and Nucleus do not state that makeup. I'm curious about the wear with those also.

I'm going to start another thread about the M6, but wouldn't mind some feedback about this as well.

[Justin]

Thanks for this Justin. Can you tell me if this is connected at all to the polymer being used in the M6?

Sure thing, Katie. I believe the polymer being used in the M6 is free of UHWMPE. I will confirm this tomorrow.

The Annulus is made of the UHWMPE that you mentioned, but the Sheath and Nucleus do not state that makeup. I'm curious about the wear with those also.

I'm going to start another thread about the M6, but wouldn't mind some feedback about this as well.

I have some detailed information on the M6 that I need to revisit and I will report back tomorrow, as I don't want to state any incorrect information now.

[Justin]

I have some detailed information on the M6 that I need to revisit and I will report back tomorrow, as I don't want to state any incorrect information now.

Katie, I took a look through my files and I can't find the information I was looking for...I'll have to do some more digging on my wife's computer tomorrow.

[Katie]

Thanks Justin and no problem. I'm away to see another surgeon, without luck in my case, so won't be able to read much till we get home anyway. I'll look for it tomorrow and thanks again.

[davemmevad]

Hi Justin,

Any luck finding this? - it is exactly the question I have about the M6 - durability of the flexible polymers. I'd emailed Spinal Kinetics but no reply yet, then saw this thread ....

Thanks
Dave

[Justin]

Hi Justin,

Any luck finding this? - it is exactly the question I have about the M6 - durability of the flexible polymers. I'd emailed Spinal Kinetics but no reply yet, then saw this thread ....

Thanks
Dave

Hi Dave,

I looked on our other computer and I can't find it for the life of me. I am going to give them a call tomorrow. Sorry for the delay in getting back to you.

Be well...and I'll post any information I get.

EDIT: By the way, I noticed the link above for the UHMWPE in Total Joint Replacement and Medical Devices is no longer allowing access to Chapter 12 (the chapter on Artificial Disc Replacement Devices) as part of the book preview on Google Books. Bummer.

[Justin]

EDIT: By the way, I noticed the link above for the UHMWPE in Total Joint Replacement and Medical Devices is no longer allowing access to Chapter 12 (the chapter on Artificial Disc Replacement Devices) as part of the book preview on Google Books. Bummer.

The link to Chapter 12 on Artificial Disc Replacement Devices is accessible as of 2/7/10. :thumpup: