ECiMa™
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Responsible Innovation

Ultra High Molecular Weight Polyethylene (UHMWPE) has proven itself over many decades as the gold standard bearing choice in total joint arthroplasty1. Several developments have been proposed to address ongoing issues surrounding wear, fracture and mid-term oxidation1. Advances in material and manufacturing technologies have attempted to address these issues, however challenges still persist in relation to long-term oxidation and material strength2,3,4. ECiMa™ has been developed in conjunction with Massachusetts General Hospital, Boston, to address some of these long standing clinical...

Cold gamma irradiated Mechanical blending of vitamin E with UHMWPE prior to consolidation allows irreversible grafting of vitamin E during the radiation process. This excites molecules to create cross-links, improving wear resistance of the material. Mechanical annealing This proprietary compression process below re-melt temperature creates extensive cross-links, while maintaining strength. vitamin E neutralises free radical Novel manufacturing process Responsible Innovation

Locking out Oxidation not all vitamin E polyethylenes are equal Whilst some companies use a diffusion or doping process, ECiMa™ uses a proprietary blending and consolidation process, grafting the vitamin E to the polyethylene molecule at the start of the manufacturing process. This offers two distinct advantages: ■■ allows uniform distribution of vitamin E throughout the polyethylene5 minimises the vitamin E elution effect seen in diffused or doped vitamin E products5. Elution rates from vitamin E polyethylenes Increased elution of vitamin E from doped/diffused vitamin E polyethylene...

The 'Goldilocks Enigma' The radiation dose and vitamin E content have been optimised with ECiMa™, providing excellent crosslink density for the radiation dose. In comparison, conventional infused vitamin E polyethylenes use up to 1% weight vitamin E which yields a lower crosslink density and poorer wear properties for a given radiation dose6. Radiation and vitamin E optimisation6 0.3% wt 1.0% wt doped/ diffused products Optimising wear resistance Responsible Innovation

Locking out Oxidation Whilst first generation HXLPEs were designed to minimise oxidation, recent research has demonstrated that cyclic loading and absorption of lipids such as squalene result in the generation of free radicals in vivo, causing oxidation7,8. The vitamin E grafted to the polyethylene acts as a reservoir able to quench free radicals, minimising the potential for in vivo oxidation9. 10-year in vivo Crossfire liner Cross-section of retrieved sample showing oxidation (white banding) Cross-section of retrieved sample showing oxidation (white banding) Crossfire shows 45x increase...

ECiMa™ tests have shown no evidence of oxidation following intensive ageing and cyclic loading where previous HXLPE liners have been shown to fail5. Oxidation (absorbance/depth mm)5 ECiMa™ 0.8 Oxidative stability Sequentially annealed HXLPE Responsible Innovation

Locking out Wear Post irradiation processing combined with high vitamin E dosage can reduce the cross-linking density of polyethylene. Whilst low temperature processes minimise cross-linking density, high temperature processes decrease material strength. A proprietary mechanical annealing process combined with low vitamin E dosage allows optimisation of cross-linking density, improving the wear resistance of ECiMa™ over conventional HXLPE and infused vitamin E products. 41% reduction compared to infused vitamin E products12 Improved wear resistance Sequentially annealed HXLPE HXLPE remelted

Locking in Strength Locking in Strength Unlike most other antioxidant and HXLPE materials, ECiMa™ utilises a mechanical annealing process which quenches free radicals at below melt temperature, maintaining the mechanical integrity of the material13,14. ■■ ■■ Mechanical integrity 45% increase in ultimate tensile strength compared with conventional HXLPE11 17% increase in ultimate tensile strength compared with modern generation antioxidant and sequentially annealed HXLPE12 Mechanical integrity vs competitor products12,15,16 Vitamin E doped, Sequentially annealed Ultimate tensile strength...

Sequentially annealed HXLPE Sequentially annealed HXLPE Mechanical integrity Oxidative stability Improved wear resistance Vitamin E doped, Sequentially annealed

Locking out Oxidation Blended vitamin E provides an ‘oxidative shield’ actively stabilising the polyethylene insert from oxidation11. Locking out Wear Cold irradiation allows cross-linking at the optimal radiation dose, providing 95% reduction in wear compared with conventional polyethylene11. Locking in Strength Mechanical annealing below the melt temperature provides a 45% increase in ultimate tensile strength compared to conventional HXLPE11. Responsible Innovation

References: 1. Muratoglu OK, Kurtz S. Alternate bearing surfaces in hip replacement: Sinha R, editor. Hip replacement. Current trends and controversies. New York, 2002. 2. Kurtz SM, Hozack WJ, Purtill JJ, Marcolongo M, Kraay MJ, Goldberg VM, et al.Significance of in vivo degradation for polyethylene in total hip arthroplasty. Clinical Orthopaedics and Related Research, 2006 ;453:47e57. 3. Wannomae K, Bhattacharyya S, Freiberg A, Estok D, Harris W, Muratoglu O. In vivo oxidation of retrieved crosslinked UHMWPE acetabular components with residual free fadicals. Journal of Arthroplasty,...