Stryker Orthopaedics Announces Knee System With Leading Wear-Resistant Technology: X3®

New Test Results Show Stryker’s Triathlon® Knee System with X3® Advanced Bearing Technology Demonstrates up to 96% Less Wear than Competitive Premium Bearing Technology

MAHWAH, N.J., July 26 /PRNewswire-FirstCall/ — In keeping with its commitment to developing effective, longer-lasting and natural-feeling joint replacements, Stryker Orthopaedics (NYSE: SYK) has married two of its most recent implant innovations in a new knee system that is yielding significantly lower wear rates in the laboratory than other leading implants available on the market today.

Laboratory testing on wear simulators shows a 96 percent wear reduction over the leading competitive premium bearing technology with the combination of Stryker’s X3®, a highly crosslinked polyethylene, and the Triathlon® Knee System, a design noted for its improved range of motion and fit. 1,2

The results of the lab testing are significant because implant wear is one of the major, non-clinical causes of implant failure. By reducing wear, Stryker expects to improve the longevity of its implants, which has emerged as one of patients’ most fundamental concerns about knee replacement surgery, according to a new survey commissioned by Stryker Corporation and conducted by Harris Interactive(R).

Although over half of the U.S. population (53 percent) are unsure how long a total knee replacement should typically last, the poll shows that longevity (45 percent) and range of motion (54 percent) are two of the three most important factors when selecting a knee replacement system, according to U.S. adults who have either had knee surgery or considered it.

“Today’s knee replacement patient is younger and more active than the patients of a generation ago,” said Mike Mogul, President of Stryker Orthopaedics.” And for them, the longevity of the implant is a fundamental concern. By focusing on wear reduction technologies, Stryker believes we can not only relieve the suffering of these patients, but allow them to continue their lifestyles while decreasing their worry about the life of their implants.”

The X3® advanced bearing technology, only available from Stryker Orthopaedics, is the first highly crosslinked polyethylene to address three of the most common, non-clinical causes of implant failure. By utilizing a patented annealing process in which the temperature is kept below the melt point following irradiation, the material properties of the polyethylene are preserved. X3® is the first polyethylene that is sequentially irradiated annealed. This means it does not need to be “remelted” and thus, the polyethylene is not weakened, which increases the wear resistance of the material while maintaining its strength. 3, 4, 5

Equally important is implant design. The intuitive and evolutionary design of Triathlon® is predicated on the worldwide clinical success of millions of Stryker knee implantations and the latest advancements in design and materials. The Triathlon® Knee System is designed to provide patients more natural motion, and the potential for greater implant longevity. It’s also available in a range of sizes to more closely fit the anatomies of both men and women, with narrower implants designed to accommodate the female bone structure and improve the fit and function for women. 2

“These latest test results demonstrating a 96 percent less wear of Stryker’s X3® with the Triathlon® Knee System over competitors’ bearing technologies once again demonstrates our commitment to developing longer- lasting implants,” says Mogul.

For additional information on knee replacement surgery and Stryker Orthopaedics’ Triathlon® Knee System with X3® technology, visit

About the Survey

This survey was conducted online by Harris Interactive on behalf of Stryker Orthopaedics between July 11 and July 13, 2006 among 2,325 U.S. adults 18 years of age or older, of whom 224 have had or considered knee replacement surgery. Figures for region, age within gender, education, household income and race/ethnicity were weighted where necessary to bring them into line with their actual proportions in the population. Propensity score weighting was also used to adjust for respondents’ propensity to be online.

With a pure probability sample of 2,325 adults one could say with a ninety-five percent probability that the overall results have a sampling error of 3 percentage points. The sampling error for the sub-samples of adults who have had or considered knee replacement surgery (n=224) and adults who have no experience with knee replacement surgery (n=2,101) is higher and varies. However that does not take other sources of error into account. This online survey is not based on a probability sample and therefore no theoretical sampling error can be calculated.

About Stryker Orthopaedics

Stryker Orthopaedics offers an extensive orthopaedic product portfolio including hip, knee and upper extremity reconstructive devices, bone cement, trauma implants and bone substitutes. For more information about Stryker Orthopaedics, visit

About Stryker Corporation

Stryker Corporation develops, manufactures and markets specialty surgical and medical products worldwide, including reconstructive implants, spinal, trauma and craniomaxillofacial systems, the bone growth factor osteogenic protein-1, powered surgical instruments, endoscopic and surgical navigation systems and patient care and handling equipment, and provides outpatient physical therapy services in the United States. For more information visit

About Harris Interactive

Harris Interactive is the 13th largest and fastest-growing market research firm in the world. The company provides research-driven insights and strategic advice to help its clients make more confident decisions which lead to measurable and enduring improvements in performance. Harris Interactive is widely known for The Harris Poll, one of the longest running, independent opinion polls and for pioneering online market research methods. The company has built what could conceivably be the world’s largest panel of survey respondents, the Harris Poll Online. Harris Interactive serves clients worldwide through its United States, Europe and Asia offices, its wholly-owned subsidiary Novatris in France and through a global network of independent market research firms. The service bureau, HISB, provides its market research industry clients with mixed-mode data collection, panel development services as well as syndicated and tracking research consultation. More information about Harris Interactive may be obtained at To become a member of the Harris Poll Online, visit

Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: Stryker, Triathlon and X3. All other trademarks are trademarks of their respective owners or holders.


  1. Stryker Orthopaedics Test Report: RD-06-013.
  2. Hitt, K., et al., “Anthropometric Measurement of the Human Knee: correlation of to the Sizing of Current Knee Arthroplasty Systems,” JBJS, Vol. 85-A, Supplement 4, 2003.
  3. X3(TM) UHMWPE maintains mechanical properties for Tensile Yield Strength and Ultimate Tensile Strength of N(2)Vac gamma sterilized UHMWPE as measured by ASTM D638. Tensile Yield Strength was 23.2 +/- 0.4 MPa and 23.5 +/- 0.3 MPa for N2Vac UHMWPE and X3(TM) UHMWPE respectively. Ultimate Tensile Strength was 54.8 +/- 2.5 MPa and 56.7 +/- 2.1 MPa for N(2)Vac UHMWPE and X3(TM) UHMWPE, respectively.
  4. Stryker Orthopaedics Triathlon(R) CR Tibial Inserts made from X3(TM) UHMWPE, 5530-G-409 show a 68% reduction in volumetric wear rate versus the same insert fabricated from N(2)\Vac gamma sterilized UHMWPE, 5530-P-409. The insert tested was Size 4, 9 mm thick. Testing was conducted under multiaxial knee simulator (multi-station MTS knee joint simulator [1]) for five million cycles using appropriate size CoCr counterfaces, a specific type of diluted calf serum lubricant and the motion and loading conditions, representing normal walking, outlined in ISO/DIS 14243-3. Volumetric wear rates were 17.7 +/- 2.2 mm(3)/10(6) cycles for standard polyethylene inserts and 5.7 +/- 1.5 mm(3)/10(6) cycles for test samples. Test inserts were exposed to a gas plasma sterilization process. In vitro knee wear simulator tests have not been shown to quantitatively predict clinical wear performance.
  5. Stryker Orthopaedics Triathlon(R) PS Tibial Inserts made of X3(TM) UHMWPE, 5532-G-409 show a 64% reduction in volumetric wear rate versus the same insert fabricated from N2\Vac gamma sterilized UHMWPE, 5532-P-409. The insert tested was Size 4, 9 mm thick. Testing was conducted under multiaxial knee simulator (multi-station MTS knee joint simulator) for five million cycles using a size 7 CoCr counterfaces, a specific type of diluted calf serum lubricant and literature or fluoroscopy based motion and loading conditions representing stair climbing [2,3]. Volumetric wear rates were 3.6 +/- 0.61 mm(3)/10(6) cycles for standard polyethylene inserts and were 1.3 +/- 0.44 mm(3)/10(6) cycles for test samples. Test inserts were exposed to a gas plasma sterilization process. In vitro knee wear simulator tests have not been shown to quantitatively predict clinical wear performance.
  6. A. Essner, A. Wang, C. Stark and J. H. Dumbleton, “A simulator for the evaluation of total knee replacement wear,” 5th World Biomaterials Congress, Toronto, Canada, May, 1996, pg 580.
  7. R. Riener, M. Rabuffetti and C. Frigo, “Stair ascent and descent at different inclinations”, Gait and Posture 15: 2002, pp. 32-44.
  8. JB. Morrison, “Function of the knee joint in various activities,” Bio-medical Engineering, 4: 1969, pp. 573-580.

SOURCE: Stryker Orthopaedics