Geometric and mechanical properties of human cervical spine ligaments.

This study characterized the geometry and mechanical properties of the cervical ligaments from C2-T1 levels. The lengths and cross-sectional areas of the anterior longitudinal ligament, posterior longitudinal ligament, joint capsules, ligamentum flavum, and interspinous ligament were determined from eight human cadavers using cryomicrotomy images. The geometry was defined based on spinal anatomy and its potential use in complex mathematical models. The biomechanical force-deflection, stiffness, energy, stress, and strain data were obtained from 25 cadavers using in situ axial tensile tests. Data were grouped into middle (C2-C5) and lower (C5-T1) cervical levels. Both the geometric length and area of cross section, and the biomechanical properties including the stiffness, stress, strain, energy, and Young's modulus, were presented for each of the five ligaments. In both groups, joint capsules and ligamentum flavum exhibited the highest cross-sectional area (p < 0.005), while the longitudinal ligaments had the highest length measurements. Although not reaching statistical significance, for all ligaments, cross-sectional areas were higher in the C5-T1 than in the C2-C5 group; and lengths were higher in the C2-C5 than in the C5-T1 group with the exception of the flavum (Table 1 in the main text). Force-deflection characteristics (plots) are provided for all ligaments in both groups. Failure strains were higher for the ligaments of the posterior (interspinous ligament, joint capsules, and ligamentum flavum) than the anterior complex (anterior and posterior longitudinal ligaments) in both groups. In contrast, the failure stress and Young's modulus were higher for the anterior and posterior longitudinal ligaments compared to the ligaments of the posterior complex in the two groups. However, similar tendencies in the structural responses (stiffness, energy) were not found in both groups. Researchers attempting to incorporate these data into stress-analysis models can choose the specific parameter(s) based on the complexity of the model used to study the biomechanical behavior of the human cervical spine.

[1]  J. Esdaile,et al.  Diagnosis and treatment of ossification of the posterior longitudinal ligament of the spine: report of eight cases and literature review. , 1992, The American journal of medicine.

[2]  G Ray,et al.  Microtrauma in the lumbar spine: a cause of low back pain. , 1988, Neurosurgery.

[3]  V. Goel,et al.  Prediction of Load Sharing Among Spinal Components of a C5‐C6 Motion Segment Using the Finite Element Approach , 1998, Spine.

[4]  A. Sances,et al.  Tensile Strength of Spinal Ligaments , 1988, Spine.

[5]  N Yoganandan,et al.  Finite element modeling of cervical laminectomy with graded facetectomy. , 1997, Journal of spinal disorders.

[6]  J Dvorak,et al.  Flexion, extension, and lateral bending of the upper cervical spine in response to alar ligament transections. , 1991, Journal of spinal disorders.

[7]  L Ekström,et al.  Mechanical properties of the human lumbar anterior longitudinal ligament. , 1992, Journal of biomechanics.

[8]  A Elhagediab,et al.  Biomechanical properties of human lumbar spine ligaments. , 1992, Journal of biomechanics.

[9]  J D Clausen,et al.  Finite element methods in spine biomechanics research. , 1995, Critical reviews in biomedical engineering.

[10]  N. Yoganandan,et al.  Finite element applications in human cervical spine modeling. , 1996, Spine.

[11]  M Guillot,et al.  Biomechanical properties of spinal ligaments and a histological study of the supraspinal ligament in traction. , 1985, Journal of biomechanics.

[12]  M M Panjabi,et al.  Quantitative anatomy of cervical spine ligaments. Part II. Middle and lower cervical spine. , 1991, Journal of spinal disorders.

[13]  A. Sances,et al.  Dynamic Response of Human Cervical Spine Ligaments , 1989, Spine.

[14]  G Ray,et al.  Mathematical and finite element analysis of spine injuries. , 1987, Critical reviews in biomedical engineering.

[15]  S L Woo,et al.  Quantitative Anthropometry of the Subatlantal Cervical Longitudinal Ligaments , 1998, Spine.

[16]  N. Yoganandan,et al.  Finite element analysis of the cervical spine: a material property sensitivity study. , 1999, Clinical biomechanics.

[17]  G A Dumas,et al.  In situ mechanical behavior of posterior spinal ligaments in the lumbar region. An in vitro study. , 1987, Journal of biomechanics.

[18]  N Yoganandan,et al.  Finite element modeling approaches of human cervical spine facet joint capsule. , 1998, Journal of biomechanics.

[19]  G Ray,et al.  Stiffness and strain energy criteria to evaluate the threshold of injury to an intervertebral joint. , 1989, Journal of biomechanics.

[20]  N Yoganandan,et al.  Functional biomechanics of the thoracolumbar vertebral cortex. , 1988, Clinical biomechanics.