The anatomic observation and clinical significance of lower lumbar vertebrae nerve root canals

Objective To improve the understanding of pathogenesis and the diagnosis and treatment by researching on the shape,structure and distribution of lumbosacral nerve canal and characteristics of pathological changes of surrounding tissues.Methods 5 lumbosacral spines from 5 adult dead bodies without spine disorders were studied.The sacrum vertebral canals,posterior coronal planes of nerve root canals,front and back wall of nerve root cannel and cross sections of intervertebral disks were anatomized using conventional operation approach of exploratory operation on posterior vertebral canals and nerve root canals.The results were compared with the observation results on 78 patients taking exploratory operations on lumbosacral vertebraes to mutual proof these results.Results After sacrum vertebral nerve roots pass through dural sac,the angles between nerve roots and the dural sac reduces with the declined sequence with the descending of the start points;the nerve roots pass through inner spinal canal and foramen,the front segment unusually will not be deformed by degeneration and abnormal stress,the common pathogenesis is extension of ossified ligamenta flava,the back segment is a fiber canal that does not go over the intervertebral disc tissue,the back segment is more related with bone degeneration and hyperplasia.Conclusion After passing through dural sac,since the sequences,start points and angles are different,the relationship between nerves and intervertebral discs are varied.When performing resection of nucleus pulposus of intervertebral disc,be careful not to hurt the nerve roots.The hyperplasia and degeneration or both can cause the entrapment of adjacent nerve roots that result in corresponded syndromes and signs at the whole distribution route of nerve roots.The surgery methods varied since the locations and characteristics are different.