Primary Knee Systems

The Stryker Primary Knee Replacement System accommodates the active and varied lifestyles of today’s patients by offering a constellation of function and sizing options. Notably, with some 60%1 of total knee replacements performed on women, Stryker Primary Knee Systems are designed with women’s needs in mind. They incorporate a variable aspect ratio to fit the female anatomy and still accommodate males.2 As a result, our offerings continue to strive to exceed orthopaedic standards for quality, longevity and patient comfort.

Stryker scientists also have developed a breakthrough in bearing technology. Stryker's X3 highly cross-linked polyethylene for knees is the only tibial-bearing insert that simultaneously delivers maintained mechanical strength3, potential for improved wear-performance4-7 and resistance to oxidation.8,9




Triathlon Total Knee

Triathlon Tritanium Knee

Scorpio NRG

Scorpio Single Axis

 
 
Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademark(s) or service mark(s): Scorpio NRG, Scorpio Single Axis, Triathlon, X3. All other trademarks are trademarks of their respective owners or holders.

1. X3 UHMWPE maintains mechanical properties for Tensile Yield Strength and Ultimate Tensile Strength of N2\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 N2\Vac UHMWPE and X3 UHMWPE, respectively. Ultimate Tensile Strength was 54.8 ± 2.5 MPa and 56.7 ± 2.1 MPa for N2\Vac UHMWPE and X3 UHMWPE, respectively.

2. Stryker Orthopaedics Triathlon CR Tibial Inserts made from X3 UHMWPE, 5530-G-409 show a 68% reduction in volumetric wear rate versus the same insert fabricated from N2\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 a) 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.

3. Stryker Orthopaedics Triathlon PS Tibial Inserts made of X3 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 a) 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. b,c 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.

4. Stryker Orthopaedics Scorpio CR Tibial Inserts made from X3 UHMWPE, 72-22-0708, show a 79% reduction in volumetric wear rate versus the same insert fabricated from N2\Vac gamma sterilized UHMWPE, 72-2-0708. The insert tested was Size 7, 8 mm thick. Testing was conducted under multiaxial knee simulator (multi-station MTS knee joint simulator a ) 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 34.6 ± 1.5 mm 3/10 6 cycles for standard polyethylene inserts and 7.3 ± 0.7 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 Scorpio PS Tibial Inserts made from X3 UHMWPE, 72-23-0708, show a 77% reduction in volumetric wear rate versus the same tibial insert fabricated from N2 \Vac gamma sterilized UHMWPE, 72-3-0708. The insert tested was Size 7, 8 mm thick. Testing was conducted under multiaxial knee simulator (multi-station MTS knee joint simulator a) for five million cycles using appropriate size CoCr counterfaces, a specific type of diluted calf serum lubricant and literature or fluoroscopy based motion and loading conditions representing stair climbing. b,c Volumetric wear rates were 35.8 ± 1.7 mm 3 /10 6 cycles for standard polyethylene inserts and were 8.2 ± 0.7 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. Stryker Orthopaedics Trident Acetabular Inserts made of X3 UHMWPE (unsterilized), 721-00-32E, show a 97% reduction in volumetric wear rate versus the same insert fabricated from N2\Vac gamma sterilized UHMWPE, 620-00-32E. The insert tested was 7.5 mm thick with an inner diameter of 32 mm. Testing was conducted under multi-axial hip joint simulation for 5 million cycles using a 32 mm CoCr articulating counterface and calf serum lubricant. X3 UHMWPE Trident acetabular inserts showed a net weight gain due to fluid absorption phenomena but yielded a positive slope and wear rate in linear regression analysis. Volumetric wear rates were 46.39 ± 11.42 mm 3 /10 6 cycles for N2\Vac gamma sterilized UHMWPE inserts and 1.35 ± 0.68 mm 3 /10 6 cycles for X3 UHMWPE (unsterilized) Trident Acetabular Inserts. Although in-vitro hip wear simulation methods have not been shown to quantitatively predict clinical wear performance, the current model has been able to reproduce correct wear resistance rankings for some materials with documented clinical results.d, e, f

      a. Essner A, et. al. “A simulator for the evaluation of total knee replacement wear”, 5th World Biomaterials Congress, Toronto, Canada, May 1996, pg 580.

      b. Riener R, et. al. “Stair ascent and descent at different inclinations”, Gait and Posture 15: 2002, pg. 32-44.

      c. Morrison JB. ‘Function of the knee joint in various activities’, Biomedical Engineering, 4: 1969, pg. 573-580.

      d. Wang A, et al. Tribology International, Vol. 31, No. 1-3:17-33, 1998.

      e. Essner A. et al. 44th Annual Meeting, ORS, New Orleans, Mar. 16-19, 1998:774.

      f. Essner A. et al. 47th Annual Meeting, ORS, San Francisco, Feb. 25-28, 2001:1007.

7. X3 UHMWPE maintains mechanical properties after accelerated oxidative aging. No statistical difference was found for Tensile Yield Strength, Ultimate Tensile Strength and Elongation as measured per ASTM D638 before and after exposure to ASTM F2003 accelerated aging (5 Atmospheres (ATM) of oxygen at 70°C for 14 days). Tensile Yield Strength was 23.5 ± 0.3 MPa and 23.6 ± 0.2 MPa, Ultimate Tensile Strength was 56.7 ± 2.1 MPa and 56.3 ± 2.3 MPa, and Elongation was 267 ± 7% and 266 ± 9% before and after accelerated oxidative aging, respectively.

8. X3 UHMWPE resists the effects of oxidation. No statistical difference was found for Tensile Yield Strength, Ultimate Tensile Strength, Elongation, Crystallinity and Density as measured per ASTM D638, D3417 and D1505 before and after ASTM F2003 accelerated aging (5 ATM of oxygen at 70°C for 14 days). Tensile Yield Strength was 23.5 ± 0.3 MPa and 23.6 ± 0.2 MPa, Ultimate Tensile Strength was 56.7 ± 2.1 MPa and 56.3 ± 2.3 MPa, Elongation was 267 ± 7 % and 266 ± 9%, Crystallinity was 61.7 ± 0.6% and 61.0 ± 0.5%, and Density was 939.2 ± 0.1 kg/m3 and 939.2 ± 0.2 kg/m 3 before and after accelerated oxidative aging, respectively.

9. X3 UHMWPE resists the effects of oxidation. No statistical difference was found for Tensile Yield Strength, Elongation, Crystallinity and Density as measured per ASTM D638, D3417 and D1505 before and after ASTM F2003 accelerated aging (5 ATM of oxygen at 70ºC for 14 days). Tensile Yield Strength was 23.5 +/- 0.3 MPa, and 23.6 +/- 0.2 MPa Ultimate Tensile Strength was 56.7 +/- 2.1 MPa and 56.3 +/- 2.3 MPa, Elongation was 267 +/- 7% and 266 +/- 9%, Crystallinity was 61.7 +/- 0.6% and 61.0 +/- 0.5% and Density was 939.2 +/- 0.1kg/m3 before and after accelerated oxidative aging, respectively.