Anatomical And Histological Study On Spinal Nerve Roots

ObjectiveTo investigate the anatomical and histological features of spinal nerve roots and provide base data for nerve transfer therapy for paraplegia.MethodsSpinal cord and nerve roots from C1to S5segments were exposed on six adult spinal specimens fixed with formalin. The diameter of each ventral and dorsal nerve root was measured with a caliper and recorded. Small nerve specimens were harvested for HE staining and immunochemical staining, and then photographed under the optical microscope. All the photos were inputted into the image analysis software for the count of spinal nerve root fibers quantity. All the measurements were analyzed by statistical software and the conclusion was finally drawn.ResultsAs for ventral roots, the diameter of C5(2.50±0.55mm) was the largest in cervical segments. In thoracic and lumbosacral segments, the diameter gradually increased from T11to S1and then decreased from S1to S5except L3. S1(1.43±0.16mm) was the thickest root and S5(0.14±0.02mm) was the thinnest one. As for dorsal roots, the diameter of C7(4.61±0.87mm) was the largest in cervical segments. From T11to S1the diameter increased and then decreased gradually from S1to S5. The diameter of dorsal roots from T1to S5was largest at S1(2.95±0.57mm) and smallest at S5(0.27±.13mm) respectively. As for the number of nerve fibers, C7(8467±1019), T12(6538±892), L3(9169±1160) and S1(8253±1419) ventral roots contained the most nerve fibers in cervical, thoracic, lumbar and sacral segments, respectively. Similarly, C7(39653±8458), T1(26507±7617), L5(34455±2740) and S1(41543±3036) dorsal roots respectively contained the most nerve fibers in their corresponding segments. ConclusionThe anatomical and histological features of spinal nerve roots from C1to S5segments were studied detailedly in the current study, which could provide the imperative data and theoretical basis for spinal nerve root transfer surgery in paraplegic patients.