Comparing the effects of laminotomy and hemilaminectomy to the spinal segment

Laminotomy is a minimally invasive endoscopic approach relating to the lamina in order to decompress the spinal cord due to disc herniation. A three-dimensional finite element model of L2, L3 and L4 was developed to investigate the effects of laminotomy, or partial unilateral laminectomy to the spinal structure. The vertebral model was extracted from computed tomography image datasets while the soft tissues such as the intervertebral discs, ligaments and the facets were modeled manually. A hemilaminectomy and two simulated laminotomy at L3 were virtually performed. Hemilaminectomy was simulated with a straight cut to one side of the lamina. Two models of laminotomy were simulated - one where half of the lamina was removed and another where one-third of the lamina was removed. Forces were applied to allow flexion and extension of the spinal segment. Stresses generated on the posterior parts and the ROM were analysed. Results showed that the minimally invasive laminotomy produced less stress on the posterior and maintain the stability of the lumbar spine.