Trabecular Metal™ Technology

The family of Trabecular Metal™ bone replacement implants represents an innovative solution for a wide range of orthopaedic applications, making it an excellent alternative to allograft bone.

The primary reason for this structural biomaterial's performance? A cellular structure that approximates the physical and mechanical properties of natural bone more closely than any other prosthetic material.^1,10,11 Highly porous, it is uniquely conducive to bone formation, enabling both strong attachment and fast, extensive tissue infiltration.(1)

Apposition and Rapid Ingrowth

Trabecular Metal implants are fabricated of elemental tantalum metal using a vapor deposition technique to create a metallic strut configuration that is similar to trabecular bone. The resulting crystalline nano-texture permits direct bone apposition.^2,3,4

With void space averaging 70 - 80%, the porosity of Trabecular Metal implants is significantly higher than the 8% found in natural cortical bone. This means more pathways for unimpeded bone ingrowth as well as the potential for greater mechanical strength across interfaces.^5,6


Trabecular Metal material is exceptionally porous. That can mean early fixation.	At three months, bone is directly apposed to a Trabecular Metal Implant.	With a metallic strut configuration similar to that of trabecular bone, the crystalline nano-texture permits direct apposition of bone.

Enhanced Fixation and Fusion 4 Weeks 8 Weeks

A primary result of traits such as these can be enhanced fixation, achieved earlier than fixation with allograft cortical bone. In fact, transcortical animal implant studies have demonstrated excellent new bone ingrowth of Trabecular Metal implants within eight weeks of surgery. Because the new bone filled the majority of available pore space within that time, fixation strength also developed rapidly.^1,5

Strong and Flexible

The mechanical properties of Trabecular Metal implants are better matched to cancellous bone than virtually any other material.^3,8

For example, its elastic modulus is a fraction of carbon fiber’s and allograft cortical bone. As a result, it facilitates physiologic load transfer to the bone, minimizing stress shielding.

4 Weeks	8 Weeks

These histologic micrographs show that new-bone filling of prepared canine cortical holes is comparable with Trabecular Metal implants (top) and without (bottom).

Elastic Modulus (GPa)

Its compressive strength is also impressive as it is greater than cancellous bone's, allowing it to withstand physiologic loading.⁸

Compressive Strength

Its high ductility allows it to handle overloads and deformation without brittle fracture.³

And a high coefficient of friction against bone helps ensure improved initial stability upon implantation.⁹

Coefficient of Friction

A Versatile Solution

Trabecular Metal material is versatile enough to be fabricated into complex implant shapes such as spinal devices and joint reconstructive implants. Implant shapes include:

Trabecular Metal™ TM-100
Trabecular Metal™ TM-300
Trabecular Metal™ TM-400
Trabecular Metal™ TM-500
Trabecular Metal™ VBR-11
Trabecular Metal™ VBR-21

Patient-friendly Qualities

According to a recent university study, tantalum, which is the primary ingredient of Trabecular Metal implants, has demonstrated significantly better performance in magnetic resonance imaging than common titanium.

What’s more, elemental tantalum is also the most biocompatible metal available, with low antigenicity to minimize the risk of immune response.

With qualities like these, it’s no wonder Trabecular Metal material has been used in medical applications since the 1940s, for implants ranging from skull plates to pacemaker leads to vascular clips. And since 1995, it has been used successfully in more than 100,000 orthopaedic surgeries, demonstrating remarkable success in diverse bone and soft-tissue applications.

Reference

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. Wigfield CC, Nelson RJ, Metcalf NH, et al. Clinical experience with two porous tantalum implants for anterior cervical interbody fusion; the difficulties in assessing fusion in a clinical setting. European Cervical Spine Research Society, London UK, 2000.

3. Medin DJ, Charlebois S, Swarts D, et al. Metallurgical characterization of a porous tantalum biomaterial (Trabecular Metalä) for orthopaedic implant applications. ASM Materials and Processes for Medical Devices Conference, September 8-10, 2003, Anaheim CA, publication in process.

4. Zou X, Li H, Bunger M, Xue Q, Eglund N, Lind M, Bunger C. Characteristic of the bone ingrowth on the porous tantalum implants in porcine lumbar interbody fusion model, ISSLS. 2002, Cleveland OH.

5. Tanzer M, Harvey E, Kay A, et al. Effect of noninvasive low intensity ultrasound on bone growth into porous coated implants. J Orthop Res. 1996;14:901-906.

6. Bobyn JD, Pillar RM, Cameron HU, et al. The optimum pore size for the fixation of porous surfaced metal implants by the ingrowth on bone. Clin Ortho Rel Res. 1980;150:263-270.

7. Bobyn JD, Lewallen D, Hanssen A, O’Keefe T, Lewis R, Unger A, Christie M, Nasser S, Tanzer M. Clinical Validation of a Structural Porous Biomaterial for Adult Reconstruction. Accepted for scientific exhibit at the 71^st AAOS, San Francisco, CA, March 10-14, 2004.

8. Krygier JJ, Bobyn JD, Poggie RA, et al. Mechanical characterization of a new porous tantalum biomaterial for orthopaedic reconstruction. Proc SIROT. Sydney Australia, 1999.

9. Zhang Y, Ahn PB, Fitzpatrick DC, Heiner AD, Poggie RA, Brown TD. Interfacial frictional behavior: cancellous bone, cortical bone, and a novel porous tantalum biomaterial. J Musculoskel Res. 1999;3(4):245-251.

10. Bobyn JD, Toh KK, Hacking SA, Tanzer M, Krygier JJ. Tissue Response to Porous Tantalum Acetabular Cups-A Canine Model. Jarthroplasty, 1999, 14(3), ppg. 347-354.

11. Bobyn JD, Hacking SA, Krygier JJ, et. al. Characterization of a new porus tantalum biomaterial for reconstructive surgery. 66th AAOS, Anahem, CA, Feb. 4-8, 1999.