Biomechanical Assessment of Human Cervical Spine Ligaments

Abstract

More data is needed to define the soft tissue components of the human cervical spine to develop and exercise mathematical analogs such as the finite element model. This study sought to determine the geometrical and biomechanical properties of spinal ligaments from the axis to the first thoracic level. 35 human cadavers were used in the study. Data were obtained for anterior and posterior longitudinal ligaments, joint capsules, ligamentum flavum, and interspinous ligament. Cryomicrotomy techniques were used to determine the geometrical characteristic. Biomechanical tests involved conducting failure tensile tests at a quasistatic rate of 10 mm/sec using in situ principles. Anterior and posterior longitudinal ligaments responded with the highest length measurements in both regions of the spine. The ligamentum flavum and joint capsules exhibited the highest area of cross-section. All ligaments demonstrated increasing cross-sectional areas in the lower cervical group compared to the mid-cervical group. Stiffness parameters were higher in the mid-cervical region than in the lower cervical region for the anterior longitudinal and interspinous ligaments and ligamentum flavum, while the reverse was true for the other ligaments. Energy was higher in the lower cervical region than in the mid-cervical region for the joint capsules, ligamentum flavum, interspinous ligament, and anterior longitudinal ligament. Anterior and longitudinal ligaments responded with the highest stress followed by the joint capsules, interspinous ligament, and ligamentum flavum. This study provides important fundamental data on the properties of human cervical spine ligaments.