Stress analysis of facets after cervical laminectomy

To investigate the biomechanical effects on the facets post-laminectomy, a three-dimensional nonlinear intact G4-C6 FEY(finite element) model was developed. The modified FE model was set up to simulate laminectomy for stress analysis. The inferior surface of C6 vertebra was constrained in all directions as boundary condition. Pure moment of 1.8Nm was applied over the top surface of C4 vertebra to simulate the movements of cervical spine under flexion, extension, lateral bending and axial rotation respectively. Results showed that there were apparent effects on facets under the above different loads after laminectomy. The stress was increased by a maximum of 187.5%. A conclusion can be drawn that the influences on the facets post-surgery should be considered when making a biomechanical evaluation on laminectomy.