Trabecular Metal™ Technology
The Best Thing Next To Bone™
The cellular structure of Trabecular Metal* resembles bone and approximates its physical and mechanical properties more closely than other prosthetic materials. The unique, highly porous, trabecular configuration is conducive to bone formation, enabling rapid and extensive tissue infiltration and strong attachment.1,2,+- Scroll down for more information: Properties, Bone ingrowth, Tissue attachment.
To see products that put Trabecular Metal to use, please click on the following links:
HIP PRODUCTSTrabecular Metal Primary Hip |
KNEE PRODUCTSTrabecular Metal |
Trabecular Metal Revision System (TMARS) |
SHOULDER PRODUCT |
SPINE PRODUCTSLinks to zimmerspine.eu site |
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Physical Properties
Trabecular Metal consists of interconnecting pores resulting in a structural biomaterial that is 80% porous, allowing approximately 2-3 times greater bone ingrowth compared to conventional porous coatings and double the interface shear strength.1,+ Trabecular Metal implants are fabricated using elemental tantalum metal and vapor deposition techniques that create a metallic strut configuration similar to trabecular bone. The crystalline microtexture of a Trabecular Metal strut is conductive to direct bone apposition.2
Elemental tantalum unites strength and corrosion resistance with excellent biocompatibility. These characteristics help explain tantalum's surgical use for more than 50 years in applications such as cranioplasty plates and pacemaker leads.3
Mechanical Properties
Trabecular Metal possesses a high strength-to-weight ratio, with mechanical properties capable of withstanding physiologic loading. The compressive strength and elastic modulus of Trabecular Metal are more similar to bone than are other prosthetic load-bearing materials.2,4 The material's low stiffness facilitates physiologic load transfer and helps minimize stress shielding.
The Trabecular Metal struts generate a friction coefficient that is 76% greater than a sintered bead coating, providing increased initial stability. 5
Exceptional Bone Ingrowth
The bone-like physical and mechanical properties of Trabecular Metal contribute to extensive bone infiltration. A transcortical implant animal study demonstrated that new bone rapidly infiltrated the Trabecular Metal. 1,2 Only 8 weeks after surgery, bone had grown into and filled the majority of available pore space. Consequently, fixation strength developed more rapidly. At 4 weeks, the bone interface shear strength of Trabecular Metal was double that of sintered beads.1,2
Histologic Micrographs
Filling of prepared cortical holes with new bone is comparable with Trabecular Metal implants (top) and without (bottom). 2 Bone filled the majority of the available pore space at 8 weeks.
Trabecular Metal has been shown to permit physiologic bone healing. In 24 week animal studies of Trabecular Metal acetabular cups, the density of ingrown bone was comparable to the density of peri-implant trabecular bone. 6
Soft Tissue Attachment
The pore size and high volume porosity of Trabecular Metal supports vascularization and rapid, secure soft tissue ingrowth. In the canine model, soft tissue adherence and vascularization occurred quickly with extensive tissue ingrowth 4 to 8 weeks after surgery.
Soft tissue attachment strength was five times greater than with sintered bead coatings at 4 and 8 weeks.7,8
Product Applications
Trabecular Metal, a structural biomaterial in many cases, does not require a solid metal substrate and can be fabricated into complex implant shapes. Clinical experience has demonstrated its versatility in diverse bone and soft tissue applications.9,10
References
1. Bobyn JD, Stackpool G, Toh K-K, et. al. Bone ingrowth characteristics and interface mechanics of a new porous tantalum biomaterial. J Bone Joint Surg. 1999; 81-B:907-914.
2. Bobyn JD, Hacking SA, Chan SP, et. al. Characterization of a new porous tantalum biomaterial for reconstructive orthopaedics. Scientific Exhibit, Proc of AAOS, Anaheim CA, 1999.
3. Black J. Biological performance of tantalum. Clin Materials. 1994;16:167-173.
4. Krygier JJ, Bobyn JD, Poggie RA, et. al. Mechanical characterization of a new porous tantalum biomaterial for orthopaedic reconstruction. Proc SIROT. Sydney, Australia, 1999.
5. Fitzpatrick D, Ahn P, Brown T, et. al. Friction coefficients of porous tantalum and cancellous and cortical bone. Proc 21st Ann Amer Soc Biomechanics. Clemson SC, 1997.
6. Bobyn JD, Toh K-K, Hacking SA, et. al. The tissue response to porous tantalum acetabular cups: A canine model. J Arthroplasty. 1999; 14:347-354.
7. Hacking SA, Bobyn JD, Toh K-K, et. al. Fibrous tissue ingrowth and attachment to porous tantalum. J Biomed Mater Res. 2000; 52:631-638.
8. Bobyn JD, Wilson GJ, MacGregor DC, et. al. Effect of pore size on the peel strength of attachment of fibrous tissue to porous surfaced implants. J Biomed Mater Res. 1982; 16: 571-581.
9. Christie MJ, DeBoer DK, Schwartz HS. Total knee arthroplasty and limb salvage with a custom tantalum femoral component. Inter. Society of Tech in Arthroplasty, Berlin, 2000.
10. O'Keefe T, Cohen RC, Averill RA, et. al. Design principles of a novel monoblock acetabular cup. Proc Australian Orthopaedic Association, Brisbane, Australia, 1999.
Some photos courtesy of JD Bobyn, PhD, Jo Miller Orthopaedics Research Laboratory, McGill University , Montreal, Canada.
*Manufactured by Implex Corp.
+Testing performed in animal models.
