Local mechanical anisotropy in human cranial dura mater allografts

M. S. Sacks, M. C. Jimenez Hamann, S. E. Otaño-Lata, Theodore Malinin

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Human cranial dura mater (CDM) allograft's success as a repair biomaterial is partly due to its high mechanical strength, which facilitates its ability to form water-tight barriers and resist high in-vivo mechanical loads. Previous studies on CDM allograft mechanical behavior used large test specimens and concluded that the allograft was mechanically isotropic. However, we have quantified CDM microstructure using small angle light scattering (SALS) and found regions of well-aligned fibers displaying structural symmetry between the right and left halves (Jimenez et al., 1998). The high degree of fiber alignment in these regions suggests that they are mechanically anisotropic. However, identification of these regions using SALS requires irreversible tissue dehydration, which may affect mechanical properties. Instead, we utilized CDM structural symmetry to estimate the fiber architecture of one half of the CDM using computer graphics to flip the SALS fiber architecture map of the corresponding half about the plane of symmetry. Test specimens (20 mm X 4 mm) were selected parallel and perpendicular to the preferred fiber directions and subjected to uniaxial mechanical failure testing. CDM allografts were found to be locally anisotropic, having an ultimate tensile strength (UTS) parallel to the fibers of 12.76 ± 1.65 MPa, and perpendicular to the fibers of 5.21 ± 1.01 MPa (mean ± sem). These results indicate that uniaxial mechanical tests on large samples used in previous studies tended to mask the local anisotropic nature of the smaller constituent sections. The testing methods established in this study can be used in the evaluation of new CDM processing methods and post- implant allograft mechanical integrity.

Original languageEnglish
Pages (from-to)541-544
Number of pages4
JournalJournal of Biomechanical Engineering
Volume120
Issue number4
StatePublished - Aug 1 1998

Fingerprint

Dura Mater
Anisotropy
Allografts
Small Angle Scattering
Fibers
Light scattering
Light
Computer Graphics
Tensile Strength
Testing
Biocompatible Materials
Computer graphics
Masks
Dehydration
Biomaterials
Strength of materials
Repair
Tensile strength
Tissue
Mechanical properties

ASJC Scopus subject areas

  • Biomedical Engineering
  • Biophysics

Cite this

Sacks, M. S., Jimenez Hamann, M. C., Otaño-Lata, S. E., & Malinin, T. (1998). Local mechanical anisotropy in human cranial dura mater allografts. Journal of Biomechanical Engineering, 120(4), 541-544.

Local mechanical anisotropy in human cranial dura mater allografts. / Sacks, M. S.; Jimenez Hamann, M. C.; Otaño-Lata, S. E.; Malinin, Theodore.

In: Journal of Biomechanical Engineering, Vol. 120, No. 4, 01.08.1998, p. 541-544.

Research output: Contribution to journalArticle

Sacks, MS, Jimenez Hamann, MC, Otaño-Lata, SE & Malinin, T 1998, 'Local mechanical anisotropy in human cranial dura mater allografts', Journal of Biomechanical Engineering, vol. 120, no. 4, pp. 541-544.
Sacks MS, Jimenez Hamann MC, Otaño-Lata SE, Malinin T. Local mechanical anisotropy in human cranial dura mater allografts. Journal of Biomechanical Engineering. 1998 Aug 1;120(4):541-544.
Sacks, M. S. ; Jimenez Hamann, M. C. ; Otaño-Lata, S. E. ; Malinin, Theodore. / Local mechanical anisotropy in human cranial dura mater allografts. In: Journal of Biomechanical Engineering. 1998 ; Vol. 120, No. 4. pp. 541-544.
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