Characterization of the structure and permeability of titanium foams for spinal fusion devices

R. Singh, P.D. Lee, T.C. Lindley, R.J. Dashwood, E. Ferrie, T. Imwinkelried

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

Titanium foams produced via the space-holder method are used for spinal fusion devices since their combination of an open-cell structure and bone-like mechanical properties promises potentially excellent bone ingrowth. Earlier studies have indicated that the size of the pores and interconnects must be greater than 100 μm for effective bone ingrowth and vascularization. Hence, the quantification of the pore and interconnect size is required for efficient scaffold design. In this study, microcomputed tomography (μCT) was used to obtain the three-dimensional (3D) structure of Ti foams with three levels of porosity (51%, 65% and 78%). Novel algorithms were then applied to quantify both the pore and interconnect size of Ti foams as a function of porosity. All foams possessed a modal pore and interconnect size in excess of 300 μm, satisfying the requirement of being greater than 100 μm. The pore and interconnect size also dominates the flow properties or permeability of open-cell structures. Therefore, the μCT data was also used to generate a mesh for computational fluid dynamics analysis to predict the permeability. The calculated permeability (117–163 × 10−12 m2 depending on direction) for the Ti foams with 65% porosity was first validated against experimental measurements (98–163 × 10−12 m2) and then compared to prior authors’ measurements in healthy cancellous bovine bone (233–465 × 10−12 m2). The close match among all the permeability values proves the suitability of the material for biomedical skeletal-implant applications.
Original languageEnglish
Pages (from-to)477-487
Number of pages11
JournalActa Biomaterialia
Volume5
Issue number1
Early online date1 Jul 2008
DOIs
Publication statusPublished - Jan 2009

Keywords

  • Titanium foams
  • Tissue scaffold
  • Porosity
  • Permeability
  • Microcomputed tomography

Fingerprint Dive into the research topics of 'Characterization of the structure and permeability of titanium foams for spinal fusion devices'. Together they form a unique fingerprint.

  • Cite this