Barrier packaging, gamma sterilization

Summary of Contemporary Barrier Packaging Techniques Used for Gamma Sterilization of UHMWPE Among Major Orthopedic Manufacturers (as of January 2003)... 

Contemporary nitrogen-filled barrier packaging for gamma sterilization of UHMWPE components used by Zimmer, inc. (Warsaw, iN). 

Perhaps surprisingly, the mean true wear rate for the conventional polyethylene liners that had been sterilized with gamma radiation in air was not significantly different from that for the liners that had been sterilized with gamma radiation in vacuum-barrier packaging. 

FIGURE 3.10 Oxidation levels in gamma sterilized polyethylene components, adapted from [1]. Packaging was classified as gas permeable, multilayer polymer film barrier, or aluminum foil and polymer film barrier (see Table 3.4). Gamma sterilization in gas permeable packaging is the equivalent to gamma sterilization in air. The expiration date was obtained directly from the packaging. (The symbol corresponds to p < 0.05 for Mann-Whitney tests.)... 

Kurtz SM, MacDonald D, lanuzzi A, van Ooij A, Isaza J, Ross ERS. In vivo oxidation and oxidation potential for polyethylene in total disc replacement following gamma sterilization in air and first-generation barrier packaging. Trans of the 54th Orthop Res Soc 2008 33 1324. 

In the Crossfire process, extruded rod bar stock is irradiated with a nominal dose of 75kGy and then annealed at 130°C [10]. Acetabular components are then machined from the bar stock, barrier packaged in nitrogen, and then gamma sterilized with a nominal dose of 30kGy. Consequently, components that have been through the Crossfire process have received a total dose of 105 kGy. 

FIGURE 20.2 Packaging for Crossfire. (A) Outer packaging box. (B) N2A ac barrier packaging used for gamma sterilization of Crossfire. 

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