Stryker | X3 Highly Crosslinked Polyethylene | Which Medical Device

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From Which Medical Device

Following on from the Crossfire highly cross linked polyethylene manufactured by Stryker, the X3 was introduced to the market in 2005. The highly cross linked X3 polyethylene is manufactured by a process of repeated gamma irradiation (3Mrads, 3 exposures) and annealing, with a final sterilization performed by a gas plasma process. The manufacturing process produces a polyethylene with 1% free radical content of conventional ultrahigh molecular weight polyethylene (UHMWPE.)(Wang et al, 2008)

Lab based hip-simulator tests have demonstrated a 70% reduction in wear over earlier generation polyethylene. The X3 shows good oxidation resistance in comparison to a non-irradiated polyethylene. There is no significant difference in yield strength or ultimate tensile strength following oxidation.

Published data using the X3 hip arthroplasty polyethylene has shown potential for use with large femoral head components because of the reduced wear rate. (Herrera et al, 2007) The X3 has also demonstrated an advantage over conventional hip liner regardless of roughening of head material. (Lee et al, 2009) The X3 knee arthroplasty polyethylene wear rates were found to be reduced by 79% and 77%; this was unaffected by accelerated aging. As the X3 is a relatively new introduction to the market, clinical evidence base is somewhat lacking, however a trial examining wear rates using radiostereometric methods has found low rates, comparable to laboratory values.(Campbell et al, 2010)

D'Antonio et al demonstrated a 58% improvement in linear wear in hips implanted with X3 bearings compared with historical controls. 

Mr Alex Sims, CT2 Trauma & Orthopaedics, Newcastle upon Tyne.

References:

1. David G. Campbell, John R. Field and Stuart A. Callary. Second-generation Highly Cross-linked X3™ Polyethylene Wear: A Preliminary Radiostereometric Analysis Study. Clinical Orthopaedics and Related Research.® Volume 468, Number 10, 2704-2709, DOI: 10.1007/s11999-010-1259-y

2. Lizeth Herrera, Reginald Lee, Jason Longaray, Aaron Essner and Aiguo Wang Hip simulator evaluation of the effect of femoral head size on sequentially cross-linked acetabular liners. 16th International Conference on Wear of Materials Volume 263, Issues 7-12, 10 September 2007, Pages 1034-1037

3. Mark A. Kester, Lizeth Herrera, Aiguo Wang, Aaron Essner Knee Bearing Technology: Where is Technology Taking Us? The Journal of Arthroplasty Volume 22, Issue 7, Supplement , Pages 16-20, October 2007

4. R. Lee, M. Cardinale, L. Loving, J. Longaray, A. Essner, A. Wang and D. Ward. Abrasion of ceramic femoral heads and its effect on pe wear. Journal of Bone and Joint Surgery - British Volume, Vol 91-B, Issue SUPP_III, 474.

5. Wang, A., Yau, S.-S., Essner, A., Herrera, L., Manley, M., Dumbleton, J. A Highly Crosslinked UHMWPE for CR and PS Total Knee Arthroplasties. Journal of Arthroplasty 23 (4), pp. 559-566. 2008

6. D'Antonio JA, Capello WN, Ramakrishnan R. Second-generation Annealed Highly Cross-linked Polyethylene Exhibits Low Wear. Clin Orthop Relat Res. 2012 Jun;470(6):1696-704. Epub 2011 Dec 9.

For related PubMed articles look here.

For clinical trials related to X3 polyethylene look here.

Last updated 20h May 2012.