Publications & Reports

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State of the art of UHMWPE in orthopaedics: Sterilisation and packaging

In this review, surgeons and researchers from Torino discuss recent observations of oxidation for gamma sterilized prostheses stored in certain types of contemporary packaging. This paper was presented on March 18, 2005, at the UHMWPE meeting at the University of Torino.

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Microstructure Changes of Extruded UHMWPE After Gamma Irradiation and Shelf Aging

Researchers at the University of Zaragoza and Madrid have investigated the lamellar microstructure of ram extruded UHMWPE after gamma irradiation in air and shelf aging using TEM and DSC. The stacking or high lamellar concentration in the subsurface in shelf-aged samples was consistent with higher crystallinity and with a degradation process controlled by oxygen diffusion and free radical distribution after gamma irradiation.

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Fatigue Resistance of Electron-Beam and Gamma Irradiation Crosslinked UHMWPE

Researchers from the University of Zaragoza and Madrid have investigated the fatigue behavior of electron beam and gamma radiation crosslinked UHMWPE. The researchers observed crossover behavior between gamma and electron beam irradiated UHMWPE as a function of the applied stress.

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Deformation, Yielding, Fracture, and Fatigue Behavior of UHMWPE

This review paper examines the deformation, yielding, fracture and fatigue behavior of conventional and highly cross-linked medical grade UHMWPE. The mechanical properties discussed include the deformation behavior of UHMWPE, the yielding associated with quasi-static tension and compression, fracture toughness, cyclic loading, and fatigue resistance.

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Datos de envejecimiento en almacenaje de tiempo real para los métodos de esterilización actuales

Investigadores de la Universidad de Utah han estudiado la densidad y el comportamiento de oxidación de dos materiales de UHMWPE esterilizados mediante plasma de gas, EtO e irradiación gamma tras cuatro años de envejecimiento de tiempo real. Se descubrió que el método de esterilización tuvo una mayor influencia en la degradación del polietileno que el tipo de resina.

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Fluid Pressure - An Alternative to Wear-Induced Lysis?

In addition to polyethylene wear, fluid pressure has been suggested to be an alternative mechanism to producing periprosthetic osteolysis. In this experimental study, the fluid pressure in a screw hole is examined across a range of implant design factors, including polyethylene thickness.

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Real-Time Shelf Aging Data for Current Sterilization Methods

Researchers from the University of Utah have studied the density and oxidation behavior of two UHMWPE materials sterilized by gas plasma, EtO, and gamma irradiation following four years of real-time aging. The type of sterilization method was found to have a larger influence on PE degradation than resin type.

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Distribución de las propiedades de falla en el UHMWPE entrecruzado

El objetivo de este estudio es evaluar las metodologías paramétricas y no paramétricas para describir las propiedades de falla del UHMWPE. Se descubrió que tanto el modelo normal como el de Weibull proporcionaron una descripción razonable de las distribuciones de las propiedades de falla para materiales de UHMWPE convencional y altamente entrecruzado.

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Molecular Chain Stretch as Multiaxial Failure Criterion

This paper outlines the theoretical framework for predicting the failure of UHMWPE under uniaxial and multiaxial loading conditions. Out of eight failure criteria evaluated in this study, the maximum molecular chain stretch criterion was found to most closely predict the failure of conventional and highly crosslinked UHMWPE.

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Failure Property Distributions for Crosslinked UHMWPE

The goal of this study was to evaluate parametric and nonparametric statistical approaches to describing the failure properties of UHMWPE. Both Normal and Weibull models were found to provide a reasonable description of the central tendency of the failure property distributions for conventional and highly crosslinked UHMWPE.

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