No abstract

No abstract

The authors present a comprehensive state-of-the-art and critical review of the finite element models of the human cervical spine. They also focused on the developments in model construction (geometry generation), constitutive law (material property) identification, loading and boundary condition details, and validation, the most important phase. A data base of available experimental sources is also provided, which can be used by the modeler for validating the finite element model. The potential developments in finite element modeling of the human cervical spine are discussed.

No abstract

A review is presented of the existing finite-element (FE) models for the biomechanics of human head injury. Finite element analysis can be an important tool in describing the injury biomechanics of the human head. Complex geometric and material properties pose challenges to FE modelling. Various assumptions and simplifications are made in model development that require experimental validation. More recent models incorporate anatomic details with higher precision. The cervical vertebral column and spinal cord are included. Model results have been more qualitative than quantitative owing to the lack of adequate experimental validation. Advances include transient stress distribution in the brain tissue, frequency responses, effects of boundary conditions, pressure release mechanism of the foramen magnum and the spinal cord, verification of rotation and cavitation theories of brain injury, and protective effects of helmets. These theoretical results provide a basic understanding of the internal biomechanical responses of the head under various dynamic loading conditions. Basic experimental research is still needed to be determine more accurate material properties and injury tolerance criteria, so that FE models can fully exercise their analytical and predictive power for the study and prevention of human head injury.

Facetectomy has a greater effect on anulus stress than on intervertebral joint stiffness. Significant increase in anulus stresses and segmental mobility may occur when bilateral facet resection exceeds 50%.

The effects of age on cervical spine injury threshold are coupled with the rate of loading experienced through the external force vector that causes the trauma. Assessment of injury mechanisms and thresholds should be based on the person's age, gender, and loading rate to determine treatment and prevent injuries.

Radiographic and biomechanical results in the goat model suggest that laminoplasty is superior to laminectomy in maintaining cervical alignment and preventing postoperative spinal deformities.