Publications & Reports

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2010 ORS Poster: In Vivo Oxidation and Mechanical Performance of Conventional, EtO-Sterilized UHMWPE Tibial Inserts

The objective of this study was to characterize the in vivo clinical and material performance of EtO-Sterilized tibial inserts. Researchers at Drexel evaluated 16 tibial inserts that were implanted an average of 4.8 y (Range: 1.7 - 9.3 years). From an in vivo oxidation perspective, the outlook for contemporary EtO-sterilized tibial inserts remains promising given the negligible oxidation values and preservation of mechanical properties documented in this study.

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2010 ORS Poster: Evaluation of Multimodal Wear Debris and Inflammation in Total Elbow Replacement Revision Tissue

Although semi-constrained total elbow replacement (TER) has been clinically successful over the past thirty years, few clinical retrieval studies exist and little is known about the component wear characteristics or the periprosthetic tissue responses to wear debris. The objective of this study was to quantify multimodal wear debris and the biological reaction in tissues from revised semi-constrained TER retrievals.

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2010 ORS Poster: Tribological Studies of Highly Crosslinked and Vitamin-E Blended UHMWPE

The objective of this study was to characterize the effects of crosslinking and Vitamin-E stabilization on the tribological properties of UHMWPE. Multidirectional wear testing in bovine calf serum was conducted on an OrthoPOD Pin-on-Disk machine. The researchers hypothesized that blending Vitamin-E into highly crosslinked UHMWPE will not only result in increased wear but also a change in wear mechanisms.

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4th UHMWPE International Meeting Proceedings - UHMWPE for Arthroplasty: from Powder to Debris

International experts from Europe, the United States, and Asia converged on Torino for two days of scientific discourse on UHMWPE on September 16-17, 2009. Topics covered at the meeting included in vivo oxidation of UHMWPE; stabilization of UHMWPE with Vitamin E and other antioxidants; crosslinking; mechanical behavior; and wear debris. Transactions of the meeting, consisting of 38 two-page abstracts for the free papers and posters, are now available for download. Presenters at the meeting have been invited to share their presentations and posters via uhmwpe.org, and are made available below individually with the permission of the authors.

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4th UHMWPE International Meeting Proceedings - UHMWPE for Arthroplasty: from Powder to Debris

International experts from Europe, the United States, and Asia converged on Torino for two days of scientific discourse on UHMWPE on September 16-17, 2009. Topics covered at the meeting included in vivo oxidation of UHMWPE; stabilization of UHMWPE with Vitamin E and other antioxidants; crosslinking; mechanical behavior; and wear debris. Transactions of the meeting, consisting of 38 two-page abstracts for the free papers and posters, are now available for download. Presenters at the meeting have been invited to share their presentations and posters via uhmwpe.org, and are made available below individually with the permission of the authors.

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4th UHMWPE International Meeting Presentation: UHMWPE Implant Technology in 2009: Current State-of-the-Art and Future Directions

This invited lecture reviews UHMWPE implant technology in 2009, and traces the evolution in the state-of-the-art over the past five years. In 2004, scientific debate centered of cross-linking and thermal stabilization, whereas today, Vitamin E stabilization is the focus of international scientific investigation. This presentation includes a survey of global use of hip and knee replacements, and concludes with suggestions for future directions of research.

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4th UHMWPE International Meeting Presentation: UHMWPE Debris: Which Chemical Characteristics?

This invited lecture by Prof. Luigi Costa postulates the chemistry of UHMWPE wear particles. The chemical structures of UHMWPE debris depend of the sterilization process (oxidation level). The UHMWPE debris contains absorbed protein and the apolar components of synovial fluid. The oxidation in vivo of UHMWPE into the joint component not in contact with cells is very difficult due to the low concentration of O2 and radicals. The PE debris can be oxidized by contact with the cell.

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4th UHMWPE International Meeting Presentation: Host Response to UHMWPE Wear Debris

This invited lecture by Prof. Yrjo Konttinen provides an overview of the host response to UHMWPE wear debris. In a global perspective, metal-on-conventional polyethylene is the most popular gliding pair in total hip replacement. This gliding couple leads to formation UHMWPE wear debris. This wear debris may lead to a cascade of biologic reactions which stimulates osteoclast formation leading to either linear but often aggressive granulomatous periimplant bone lysis. The cellular and molecular consquences of wear debris are reviewed as motivation for the avoidance of wear by crosslinking and the addition of minute amounts of Vitamin E.

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4th UHMWPE International Meeting Presentation: Stabilisation of UHMWPE with Vitamin E: Chemical Mechanisms

This invited lecture by Dr. Pierangiola Bracco from the University of Torino reviews the stabilization chemistry of Vitamin E blended with UHMWPE. Vitamin E is an excellent biocompatible stabilizer for UHMWPE. Blending of Vitamin E with UHMWPE powder results in a highly homogeneous distribution of Vitamin E in the polymer bulk. The presence of Vitamin E in UHMWPE prior to irradiation slightly decreases the crosslinking efficiency. Blending of Vitamin E with UHMWPE powder provides stabilization through all the following processing steps. The transformation products of Vitamin E after irradiation irradiation are still able to provide an excellent stabilizing effect.

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4th UHMWPE International Meeting Presentation: Nitroxides as Free Radical Scavengers in UHMWPE

Nitroxides are stable organic compounds that have a strong paramagnetic signal and are very efficient in preventing lipid peroxidation and providing radioprotection in biological tissues. Nitroxides are also efficient carbon-centered free radical scavengers in vivo. Through the electron transfer mechanism, radiolytically-produced carbon-centered free radicals in UHMWPE will combine with the nitroxide radical. This work aims to demonstrate the scavenging of residual alkyl and allyl free radicals in UHMWPE with nitroxide doping.

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