Triathlon Tritanium Knee System
Table of Contents Cementless TKA... 4 Why Cementless TKA?... 4 Cementless TKA - Clinical History... 4 Published RSA Results Comparing Fixation Methods... 5 Biologic Fixation... 6 Tritanium... 6 What is 3D Printing?... 6 Peri-Apatite (PA) Technology... 7 Knee Design... 8 Importance of Knee Design... 8 SOMA Designed... 8 Initial Stability... 9 Metal-Backed Patella... 10 Procedural Procedural Highlights... 11
Triathlon Tritanium Knee System Cementless TKA Why Cementless TKA? Cementless TKA is growing in popularity and is a fast-growing trend. 1 Recent studies support that cementless TKA achieve excellent results, 2-4 including a 2012 study showing 96% survivorship at up to 18 years without aseptic loosening. 2 The kinematics of Triathlon coupled with the latest in highly porous biologic fixation technology offers a knee system like no other. For surgeons interested in cementless TKA, Triathlon Tritanium implants now allow surgeons to expand its use in more patients. Read more about Triathlon s cementless product offerings, including Stryker s enabling technologies like 3D printing technology and SOMA bone morphology analytics design. 28 Biologic Fixation Cementless TKA offers an alternative over bone cement. The fixation is biologic as opposed to mechanical in the case of bone cement. Cement & Mixing Device Costs Combined with associated costs of the bone cement and a mixing device, there may be cost savings available for the hospital when using Tritanium cementless technology. OR Efficiency The modern economics of total joint arthroplasty and available health care resources also contribute to a renewed interest in cementless TKA through increased operating room efficiency. Successes in THA Cementless THA has been a clinically successful procedure 5 and the orthopedic community is now looking to achieve these results in TKA. Cementless TKA - Clinical History Multiple successful outcomes have been reported for total knee arthroplasty (TKA) with cementless technology. 2-4 In one study on cementless (HA-coated) knees in young, active patients, none of the implants in patients under 45 years old had failed at the latest follow-up, as far out as 11 years. 4 Clinical Studies demonstrating over 10 years of follow-up Study Implant Survivorship Melton et al (2012) 2 Active Total Knee Replacement 96% at up to 18 years Epinette et al (2007) 6 HA Omnifit Knee Prosthesis-Series 3000 Watanabe et al (2004) 7 Osteonics Series 3000 98% at 11 years 100% at 10 years and 96.7% at 13 years 4
Published RSA Results Comparing Fixation Methods Stable primary fixation of the implant is a prerequisite for biologic fixation. 8 An RSA study comparing fixation method with the same prosthesis showed no statistical difference between fixation methods in displacement at the prosthetic edge, subsidence, and lift off. 8 5
Triathlon Tritanium Knee System Biologic Fixation Tritanium Tritanium implants are the latest evolutions in the Triathlon cementless knee portfolio. Tritanium is highly porous metal biologic fixation technology. Stryker s 3D printing technology allows for titanium powder to be applied in numerous layers and provide a complex porous structure in appropriate areas of the implant. The proximal surface area for Tritanium on the tibial baseplate has been extended to part of the pegs and keels to allow the minor inconsistencies of bone resection and morphology to remain in close contact with the underside of the implant. Triathlon Tritanium baseplate and metal-backed patella components are manufactured using this technology. Triathlon Tritanium is also indicated for cemented applications, providing surgeons intraoperative flexibility to decide on the fixation method with the actual component once bone quality is assessed. Material Properties Tritanium Baseplate Mean Pore diameter (um) 527 497 Coefficient of friction 1.02.80 Mean porosity 68% 65% Tritanium Metal-Backed Patella What is 3D Printing? Additive Manufacturing, or 3D printing, is a manufacturing technique that takes a computer model of a component and grows parts layer by layer. The type of process used for Tritanium is a focused laser beam used to melt layers of metal powders, giving Stryker the ability to create unique porous structures. This 3D printing process makes it possible to selectively position porous structures in desired zone. 6
Peri-Apatite (PA)Technology Peri-Apatite was developed to coat hydroxyapatite onto porous coated fixation surfaces. Triathlon s cementless femoral components are manufactured with this technology. As opposed to plasma-sprayed HA coatings, Peri-Apatite HA coating wraps itself around the circumference of the porous surface, which is designed to increase the HA surface available for fixation. 9 The most recent study published on the Triathlon (PA-coated) cementless system showed that all implants demonstrated evidence of stable biologic fixation at a mean of 3 years. 3 Triathlon PA Clinical Study Results Implant Triathlon Peri-Apatite (PA) Cementless PA PS Femur PA Screw-Fix Tibia PA Metal-Backed Patella Results 110 TKAs with no implant related revisions at mean of 3 years. All implants demonstrated radiographic evidence of stable biologic fixation with no evidence of loosening, osteolysis, stress shielding, or progressive radiolucent lines. 7
Triathlon Tritanium Knee System Knee Design Triathlon & The Single Radius Stable primary fixation of the implant is a prerequisite for biologic fixation. 8 The less constrained the design, the less potential for stresses generated at the articulating surface to be transferred to the bone-implant interface. 10 Triathlon CR and PS systems are designed to minimize dynamic stress transfer to the tibial fixation interface by providing minimal resistance to internal and external motion in hyperextension and throughout flexion, and by locating the bearing sulcus directly over the tibial keel to help reduce sagittal rocking during ambulation. 3 Additionally, Triathlon s locking mechanism is designed to help minimize micromotion. 32 Full Perimeter Locking Wire Locking tabs to secure wire Anti-Rotation Island designed to help minimize insert micromotion and creep 32 SOMA Designed SOMA is the world s largest database of bone morphology size, shape, density, stiffness, and inner and outer cortical diameters drawn from diverse populations. SOMA, the Stryker Orthopedic Modeling and Analytics system, was used to optimize the depth and placement of the Tritanium pegs. 28 The location and length of the pegs is tailored for each size, and was determined using SOMA analysis of over 350 bones. 28 The addition of the pegs is intended to provide more purchase into outermost, dense cancellous bone. This is designed to address patients with compromised bone quality. 8
Initial Stability Given the importance of stable primary fixation, 8 underside features of the Tritanium baseplate were designed to reduce micromotion and lift off. 23,31 3D printing technology provided Stryker engineers the ability to think of a design, 3D print it, and then test it. Many designs were tested, but none provided greater stability than the Triathlon keel design. 23,31 Peak pull out force of 6 different peg designs. 31 Bullet Cruciform represents the design chosen for the Triathlon Tritanium baseplate. Pull Out Force [N] 100 80 60 40 20 0 Bullet Cruciform Zimmer Hex Biomet Square Bullet Barb 10mm Bullet 5mm Bullet Lateral Liftoff/Compression 23 Anterior Liftoff/Compression 23 0.6 > Liftoff 0.8 > Liftoff 0.4 > Compression 0.6 > Compression 0.2 > 0.4 > 0 > 0.2 > -0.2 > 0 > -0.4 > -0.2 > -0.6 > -0.4 > -0.8 > -0.6 > Dual Hex Pegs (NexGen Trabecular Metal) Keel and 4 Pegs (Triathlon Tritanium) Dual Hex Pegs (NexGen Trabecular Metal) Keel and 4 Pegs (Triathlon Tritanium) Medial Liftoff/Compression 23 Posterior Liftoff/Compression 23 0.8 > 2 > 0.6 > 0.4 > Liftoff Compression 1.5 > Liftoff Compression 0.2 > 1 > 0 > -0.2 > 0.5 > -0.4 > 0 > -0.6 > -0.8 > -0.5 > -1 > -1 > Dual Hex Pegs (NexGen Trabecular Metal) Keel and 4 Pegs (Triathlon Tritanium) Dual Hex Pegs (NexGen Trabecular Metal) Keel and 4 Pegs (Triathlon Tritanium) 9
Triathlon Tritanium Knee System Metal-Backed Patella The Triathlon Tritanium metal-backed patella offers a highly porous biologic fixation surface in a monoblock design. The patellofemoral track and polyethylene material in the Triathlon Tritanium Metal-Backed Patella has been studied clinically in the Triathlon PA metalbacked patella design, and one study using that design demonstrated no patella failures. 3 While the bone-facing architecture has been created to encourage biologic fixation, a different interface architecture was designed to enhance the association between the metal backing and the polyethylene. Direct compression molding allows the polyethylene to penetrate the porous metal surface to minimize dissociation. 12 A solid barrier layer between these two unique porous surfaces can provide added strength, allowing for a smaller metal backing and greater polyethylene thickness in areas that have historically led to revision. 30 The peg diameter has also been increased to allow for greater pressfit with the native patella. 10
Procedural Procedural Highlights The Triathlon Tritanium baseplate can be implanted with minimal additional preparation compared to a cemented Triathlon implant. The only additional step is to prepare the tibia for the pegs, which are designed to aid in initial stability. 31 Lateral Medial The four peg prep holes on the Tibial Peg Drill Template correspond to the pegs on the implant. A new Patella Inserter and Patella Captures will help evenly distribute the forces over the entire implant and allow the device to be seated evenly and completely onto the prepared bone surface of the native patella. 11
References 1. Table 54: Primary TKA Implant Market. US Markets for Large-Joint Reconstructive Implants 2013. Millennium Research Group. March 2013. Pg. 84. 2. Melton J et al. Long-term outcome in an uncemented, hydroxyapatite-coated total knee replacement. JBJS Br. VOL. 94-B, No. 8, August 2012. 1067-1070. 3. Harwin S, Kester M, Malkani A, Manley M. Excellent Fixation Achieved With Cementless Posteriorly Stabilized Total Knee Arthroplasty. The Journal of Arthroplasty Vol. 28 No. 1 2013. 4. Tai CC, Cross MJ. Five- to 12-year follow-up of a hydroxyapatite-coated, cementless total knee replacement in young, active patients. J Bone Joint Surg [Br] 2006;88-B:1158-63. 5. Trumm et al. Revision with Cementless Acetabular Components. J Bone Joint Surg Am. 2012;94:2001-4 6. Epinette et al. Hydroxyapatite-coated total knee replacement. CLINICAL EXPERIENCE AT 10 TO 15 YEARS. J Bone Joint Surg [Br] 2007;89-B:34-8. 7. Watanabe H, Akizuki S, Takizawa T. Survival analysis of a cementless, cruciate-retaining total knee arthroplasty. Clinical and radiographic assessment 10 to 13 years after surgery. J Bone Joint Surg Br. 2004;86:824-829. 8. Nilsson K et al. Evaluation of Micromotion in Cemented vs Uncemented Knee Arthroplasty in Osteoarthritis and Rheumatoid Arthritis. Journal of Arthroplasty. Vol 6. No 3. September 1991. 265-278. 9. Serekian, Paul (2004), Hydroxyapatite: from Plasma Spray to Electrochemical Deposition. From: Fifteen Years of Clinical Experience with Hydroxyapatite Coatings in Joint Arthroplasty: Edited by Jean-Alain Epinette and Michael T.Manley. Springer, France, pp 29-33. 10. Bhimji S, Kester M, Schmalzried T. Rotational Constraint of Posterior-Stabilized Total Knee Prostheses. J Knee Surgery. 2008; 21: 315-319. 11. Stryker Test Report RD-09-088 12. Stryker Test Report RD-12-044 13. Yong CK, Choon DSK, Soon HC. Midterm outcome of the duracon total knee arthroplasty. Journal of Orthopaedic Surgery 2008;16(2):197-200. 14. Mont M, Yoon T, Krackow K, Hungerford D. Eliminating Patellofemoral Complications in Total Knee Arthroplasty Clinical and Radiographic Results of 121 Consecutive Cases Using the Duracon System. Journal of Arthroplasty Vol. 14 No. 4 1999 15. Kraay MJ, Darr OJ, Salata MJ, Goldberg VM. Outcome of metal-backed cementless patellar components: The effect of implant design. Clin Orthop. 2001; (392):239-244. 16. Bayley JC, Scott RD, Ewald FC, Holmes GB Jr. Failure of the metal-backed patellar component after total knee replacement. J Bone Joint Surg Am. 1988 Jun; 70(5):668-74. 17. Clinical Value dossier for Trabecular Metal Technology. Zimmer. 97-7255-098-00. 18. Stryker Test Report RD-12-117 19. Zimmer NexGen Trabecular Metal Tibial Tray. Zimmer. 97-5954-001-00. 20. Stryker Test Report RD-12-113 21. Stryker Test Report RD-13-011 22. Meneghini et al. Early Failure of Cementless Porous Tantalum Monoblock Tibial Components. Journal of Arthroplasty. The Journal of Arthroplasty 28 (2013) 1505 1508. 23. Bhimji et al. The effect of fixation design on micromotion of cementless tibial baseplates. ORS 2012. Poster 1977. 24. Stryker Test Report RD-12-118 25. Stryker Technical Memo to DHF 92911. Protocol 39147-P28. The Osseointegration of Porous Materials Using a Rabbit Femoral Defect Model. 26. Small et al. Changes in tibial bone density measured from standard radiographs in cemented and uncemented total knee replacements after ten years follow-up. Bone Joint J 2013;95-B:911 16 27. Stryker Test Report RD-13-129 28. Stryker Test Protocol 92911 29. Kraay MJ, Darr OJ, Salata MJ, Goldberg VM. Outcome of metal-backed cementless patellar components: The effect of implant design. Clin Orthop. 2001; (392):239-244. 30. Bayley JC, Scott RD, Ewald FC, Holmes GB Jr. Failure of the metal-backed patellar component after total knee replacement. J Bone Joint Surg Am. 1988 Jun; 70(5):668-74. 31. Stryker Test Report RD-13-107 32. Bhimji S et al. Tibial Insert Micromotion of Various Total Knee Arthroplasty Devices. Journal of Knee Surgery. Volume 23. No 3. 153-162. 325 Corporate Drive Mahwah, NJ 07430 t: 201 831 5000 www.stryker.com 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 product offerings. A surgeon must always refer to the package insert, product label and/or instructions for use before using any Stryker product. The products depicted are CE marked according to the Medical Device Directive 93/42/EEC. Products may not be available in all markets because product availability is subject to the regulatory and/or medical practices in individual markets. 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