Not all mechanical properties are created equally.  Zimmer believes that fatigue strength is a more important indicator of clinical success.

  • The fatigue properties of Trabecular Metal Material compare well to the fatigue properties of cancellous bone.2  In fact, the reference Biomet used to obtain the compressive peak stress of Trabecular Metal Material also includes fatigue properties for Trabecular Metal Material.  But Biomet is silent on this comparison.  Why?
  • It is not surprising that Regenerex exhibits a higher compressive peak stress than Trabecular Metal Material.  Trabecular Metal Material is 10% more porous than Regenerex.  A less porous material would be expected to exhibit a higher peak stress.

References

  1. Bobyn JD, Hacking SA, Krygier JJ, Chan SP, Toh KK, Tanzer M. Characterization of a new porous tantalum biomaterial for reconstructive orthopaedics Scientific Exhibition: 66th Annual Meeting of the American Academy of Orthopaedic Surgeons; February 4-8, 1999; Anaheim, CA.
  2. Zardiackas LD, Parsell DE, Dillon LD, Mitchess DW, Nunnery LA, Poggie R. Structure, metallurgy, and mechanical properties of a porous tantalum foam . J Biomed Mater Res. 2001;58(2):180-187.
  3. Lewallen DG, Meneghini M, Mardones RM, Poggie RA, Hanssen AD. Revision hip arthroplasty with porous tantanlum augments and acetabular shells. Scientific Exhibition: 2006 Annual Meeting of the American Academy of Orthopaedic Surgeons; March 22-26, 2006; Chicago, IL.
  4. Macheras GA, Papagelopoulos PJ, Kateros K, Kostakos AT, Baltas D, Karachalios TS. Radiological evaluation of the metal-bone interface of porous tantalum monoblock acetabular component. J Bone Joint Surg (Br). March 2006;88(3):304-309.
  5. Gruen TA, Poggie RA, Lewallen DG, et al. Radiographic evaluation of a monoblock acetabular component—a multicenter study with 2- to 5-year results. J Arthroplasty. 2005;20(3):369-378.
  6. Hacking SA, Bobyn JD, Toh K, Tanzer M, Krygier JJ. Fibrous tissue ingrowth and attachment to porous tantalum. J Biomed Mater Res. December 15, 2000;52(4):631-638.
  7. Zhang Y, Ahn P, Fitzpatric D, Heiner A, Poggie R, Brown T. Interfacial frictional behavior: cancellous bone, and a novel porous tantalum biomaterial. J Musculoskeletal Res. 1999;3(4):245-251. 
  8. Shirazi-Adl A, Dammak M, Paiement G. Experimental determination of friction characteristics at the trabecular bone/porous-coated metal interface in cementless implants. J Biomed Mat Res. 1993;27:167-175.
  9. Medlin DJ, Charlebois S, Swarts D, Shetty R, Poggie RA. Metallurgical characterization of a porous tantalum biomaterial ( Trabecular Metal ™ ) for orthopaedic implant applications . ASM Materials and Processes for Medical Devices Conference; September 8-10, 2003; Anaheim CA.

* Biomet Orthopedics. Regenerex Porous Titanium Construct. 2006; Form No. Y-BMT-970/033106/M.