Abstract
This study was undertaken to investigate the biomechanical effects of the human cervical spine under intact, and laminectomy with and without graded facetectomy conditions. An anatomically accurate finite element (FE) model of a three-segment (C4-C6) spine unit was developed. The FE model was validated under physiologic flexion, extension, lateral bending, and axial torsion loading modes. The model response matched well with the experimental data. The gross external (angular rotation) and the internal responses (e.g., superior and inferior intervertebral disc stress) were delineated under these physiological loading modes. Laminectomy markedly altered the cervical angular motion and the disc stress under flexion loading compared to the other loading modes. Laminectomy with facetectomy increased the angular motion and the inferior disc stress notably under flexion without affecting the adjacent superior disc. Facet resection of more than 50 percent caused pronounced increase of angular rotation and intervertebral disc stress.
