Mechanical and physiological effects of dentatotomy

Abstract

✓ The role of the dentate ligaments in the pathogenesis of myelopathy secondary to disease conditions that alter the normal biomechanics of the spinal canal was studied in 14 dogs. The effects of posterior cord elevation on somatosensory evoked potentials (SSEP's) and tension requirements were compared before and after dentate ligament section in acute experiments. At levels of posterior elevation usually within the confines of the canine canal, the dentate ligaments were the most significant element increasing tension requirements and SSEP alterations. Human cadaver studies also showed an approximate 50% reduction of force after dentatotomy. These findings suggest that after dentate ligament section the applied tension is distributed over a longer segment of the cord with a reduction in tension and disruption of axonal conduction at the level at which the force was applied.