Research On The Level Of The Conus Medullaris Termination Via Magnetic Resonance Imaging In Children

Objective The range of the level of the conus medullaris termination plays an important role in clinical lumbar puncture,positioning of spinal anesthesia,and diagnosis of tethered cord syndrome.Due to the rapid growth and development of children's spine and spinal cord,the level of the conus medullaris termination of the children exhibits significant differences from those of adults.Accurately locating the position of the conus medullaris termination could reduce chance of surfacing serious neurological complications caused by spinal cord injury,which is very important in clinical.Methods By retrospective analysis of 231 cases of lumbosacral magnetic resonance children imagings in Jiang Su Province,the position of the conus medullaris termination was observed on the sagittal T1 weighted image.The position of the intervertebral disk or the vertebral body closest to the tip of the conus medullaris was recorded as the conus level.Each vertebral body was equally divided into upper(U),middle(M),and lower section(L),respectively.Moreover,the disc was treated as a separate segment.Base on the age,the 231 samples were divided into seven groups(<1 month,1-6 months,6-12 months,1-2 years,2-5 years,5-10 years,and 10-15 years).Results 1)The conus medullaris termination of 231 children was in the range from T12-L1/3 to L3-L1/3.The highest distribution frequency was L1-L1/3(21.21%)and average location was at L1-L1/3 with a standard deviation of 2.19,which was equivalent to 2/3 vertebral body.2)The average position of the conus medullaris termination of 17 newborns was at the level of L1-L2 intervertebral space.3)The level of the conus medullaris termination of small age group samples were compared to those of older children.The comparison results exhbit statistically significant.It was found that the average position of conus medullaris termination gradually moved cephalad with the increase of children ages.4)The average position of the conus medullaris termination of 122 male children was between the L1-L1/3,which is same as that of 109 female children.There was no significant difference between the male and female samples.Conclusion 1)The conus medullaris termination of children was in the range from T12-L1/3 to L3-L1/3 and the average location was at L1-L1/3.In this study,the frequency of the conus medullaris termination in the L3 level was 1.73%.Although this probability was low,it was not to recommended to conduct clinical lumbar puncture in the L2-L3 intervertebral space in order to avoid spinal cord injury.2)The average position of the conus medullaris termination of newborns was at the level of L1-L2 intervertebral space,which is close to the adult level.3)It was found that the average position of conus medullaris termination gradually moved cephalad with the increase of children ages.4)There was no significant difference between the male and female samples of the level of the conus medullaris termination in children.