Evidence-based use of HXLPE: Where to look?
Message from Michael Mont, MD
Northwell Health, New York
Message from Michael Mont, MD
Northwell Health, New York
When HXLPE was initially introduced, there were questions as to whether it would improve our outcomes and would it stand the test of time, especially in total knee arthroplasty (TKA). In our recent study published in the Journal of Arthroplasty, we performed the largest TKA revision retrieval study of highly crosslinked polyethylene (HXLPE) on a commissioned cohort to date. This X3 study was the result of a long-standing, multi-center retrieval program with the analysis being carried out at Drexel University in Philadelphia under the guidance of Steven Kurtz, Ph.D. Retrievals provide important information about what is actually occurring in vivo and can provide evidence-based scientific knowledge.
The results were positive, and complement the other clinical studies on Stryker hip and knee polyethylene products. Here is what we found and why I believe that these types of studies are important for understanding the role of HXLPE.
In the retrieval analysis, we saw compelling support of X3 in a TKA given its patented sequential annealing process which allows for wear resistance1,2, mechanical strength3, and oxidation resistance4 without the use of additives. There were multiple reasons for the TKA revisions in our retrieval study; however, we found that there were no inserts revised due to mechanical failure that could be attributed to oxidative damage5. In addition, the X3 group exhibited a similar profile for oxidation in vivo compared to conventional gamma/inert polyethylene5.
This is noteworthy as it indicates that oxidative concerns due to free radicals and subsequent delamination failures have been mitigated with the use of X3. Oxidation resistance is an inherent characteristic of the product itself given its unique three step sequential annealing process6.
Our findings are further supported by the Australian Joint Registry data which showed that there is increased survivorship using HXLPE compared to non-HXLPE7. The registry also showed an increase in survivorship at 10 years with Triathlon PS and X3 compared to non-HXLPE, with a sample size of thousands of patients 7.
Since its launch in 2005, X3 has had promising results with Stryker’s hip implants including a recent study by Campbell et. al. The study reported a 10-year wear rate of less than 10 microns per year highlighting X3’s characteristic of wear resistance8. And more recently in 2015, building upon the success of X3 in TKA and THA, Stryker expanded its X3 polyethylene offering to incorporate Mako Partial Knee implants.
The significant amount of clinical data on Stryker’s X3 annealed poly further supports its use across multiple knee3,7,9,10 and hip8,11-15 applications.
Resources:
References:
1. Bonutti et al. Influence of Design and Bearing Materials on Wear: Comparing Two Different TKA Designs. ISTA 2012. October 1012.
2. Stryker Test Report RD-13-109. Wear Evaluation of a hindered-Phenol Polyethylene compared to X3 Polyethylene. 2013.
3. Meneghini at el. Multicenter Study of Highly Cross-linked vs Conventional Polyethylene in Total Knee Arthroplasty. The Journal of Arthroplasty 31 (2016) 809-814.
4. Yau et al. Real-Time Shelf Aging of Sequential Crosslinked and Annealed UHMWPE. 55th Annual Meeting of the Orthopaedic Research Society. Poster No.450
5. Oxidation, Damage Mechanisms, and Reasons for Revision of Sequentially Annealed HXLPE in Total Knee Arthroplasty. Kurtz et al. The Journal of Arthroplasty 2018 Apr;33(4):1235-1241. doi: 10.1016/j.arth.2017.09.036. Epub 2017 Sep 25.
6. US Pat. 7,517,919
7. Australian Orthopaedic Association National Joint Replacement Registry. 2017.
8. Wear of a Second-Generation XLPE Liner Remains Low at 10 Years: An RSA Study. Campbell et al. 5th Annual International RSA Conference, October 6-8, 2017, Adelaide, SA, Australia.
9. Harwin et al. Clinical and Patient-reported Outcomes of Primary TKA With a Single-radius Design. Orthopedics. July 2013. Volume 36. No. 7.
10. National Joint Registry for England, Wales and Northern Ireland. 14th Annual Report 2017.
11. Wear Rates with Large Metal and Ceramic Heads on a Second Generation Highly Cross-Linked Polyethylene at Mean 6-Year Follow-Up. Gaudiani et al. The Journal of Arthroplasty, Sep 2018, 33:590- 594.
12. Early Experience with Dual Mobility Acetabular Systems Featuring Highly Cross-Linked Polyethylene Liners for Primary Hip Arthroplasty in Patients Under Fifty-Five Years of Age: An International Multi-Centre Preliminary Study. Epinette et al. International Orthopedics, Mar. 2017, 41(3): 543-550.
13. Second-Generation Annealed Highly Crosslinked Polyethylene has Low Wear at Mean Seven Year Follow-up. D’Antonio et al. Surgical Technology International, Nov. 2014, 25: 219-226.
14. Comparison of Wear Rate and Osteolysis Between Second-Generation Annealed and First-Generation Remelted Highly Cross-Linked Polyethylene in Total Hip Arthroplasty. A Case Control Study at a Minimum of Five Years. Takada et al. Orthopaedics and Traumatology: Surgery and Research, Feb. 2017, 103: 537-541
15. Comparative Results from a National Joint Registry Hip Data Set of a New Cross Linked Annealed Polyethylene vs Both Conventional Polyethylene and Ceramic Bearings. Epinette et al. The Journal of Arthroplasty, Jul. 2016, 31(7): 1483-1491.
Dr. Mont is a paid consultant of Stryker Orthopaedics. The opinions expressed by Dr. Mont are those of Dr. Mont and not necessarily those of Stryker.
Individual experiences may vary. A surgeon must always rely on his or her own professional clinical judgment when deciding whether to use a particular product when treating a particular patient. Stryker does not dispense medical advice and recommends that surgeons be trained in the use of any particular product before using it in surgery. The information presented is intended to demonstrate the breadth of Stryker’s product offerings. A surgeon must always refer to the package insert, product label and/or instructions for use before using any of Stryker’s products. Products may not be available in all markets because product availability is subject to the regulatory and/or medical practices in individual markets. Please contact your sales representative if you have questions about the availability of products in your area.
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