Mechanical Characterization of Non-degraded Porcine Annulus Fibrosus Material Properties

Document Type

Article

Publication Date

4-2026

Publisher

Springer

Source Publication

Annals of Biomedical Engineering

Source ISSN

0090-6964

Original Item ID

DOI: 10.1007/s10439-024-03629-3

Abstract

Purpose

Porcine cervical spines are commonly used as a surrogate for human lumbar spines due to their similar anatomic and mechanical characteristics. Despite their use in spinal biomechanics research, porcine annulus fibrosus (AF) yield and ultimate properties have not been fully evaluated. This study sought to provide a novel dataset of elastic, yield, and ultimate properties of the porcine AF loaded in the circumferential direction.

Methods

AF specimens were dissected from porcine cervical spines (C3/C4-C6/C7) oriented in the circumferential direction. Specimens were uniformly hydrated before being quasi-statically distracted to failure. Linear modulus, yield stress and strain, ultimate stress and strain, and ultimate strain energy density were calculated. Differences between spinal levels, circumferential regions, and radial regions were identified using multifactor ANOVA tests.

Results

AF specimens showed a regionally dependent response between outer and inner radial regions, but not between spinal level and circumferential region. The outer region was significantly stronger and stiffer than the inner regions. In both outer and inner tissue, mechanical yield occurred at approximately 80% of their ultimate properties.

Conclusion

This study generated a novel dataset of elastic, yield, and ultimate properties of the porcine AF. The data can be used in future research that requires a robust database of healthy, non-degenerated AF mechanical properties, such as the development of future finite-element models.

Comments

Annals of Biomedical Engineering, Vol. 54, No. 4 (2026, April): 1099-1107. DOI.

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