Distribution Characteristics About The End Position Of Conus Medullaris In Adults Between The Korean And Han Nationality

Objective:To analysis distribution characteristics about the end position of conus medullaris in adults between the Korean and Han nationality,to provide reference for spinal anesthesia puncture in adults.Methods:To retrospective analysis the lumbar MRI examination data of this hospital in 843 cases.The vertebral level of the spinal cord tip defined by dividing the vertebral body and intervertebral space into four,segments:upper,middle and lower thirds,and the intervertebral space.The end position of conus medullaris is measured by T1WI sagittal scanning in the supine position,and the straight-line perpendicular to the longitudinal axis of the spinal cord is drawn from the farthest point of the conus medullaris.The number of vertebrae was determined by looking at the relationship between the full and crown of the lumbar spine and the ribs.To observe and record the end position of conus medullaris and analysis distribution characteristics of the end position of conus medullaris in adults between the Korean and Han nationality.Results:The highest point of the end position of conus medullaris of the Korean nationality is at T11-12,and the lowest point is at the upper part of L3 centrum,mainly at L1 upper 1/3(21%),L1 middle 1/3(15.7%),Li lower 1/3(23.5%)and L1-2(16.5%),L1 centrum reaches L1-2.The highest point of the end position of conus medullaris of the Han nationality is at T12 upper 1/3,and the lowest point is at L2-3,mainly at L1 upper 1/3(23.7%),L1 middle 1/3(16.7%),L1 lower 1/3(18.7%)and L1-2(14.6%),L1 centrum reaches L1-2.The level of the end position of conus medullaris in male is significantly higher than that in female(P<0.05),and in Han nationality males is significantly higher than Korean nationality males(P<0.05).There is no statistical difference between Han nationality females and Koean nationality females(P>0.05).Conus medullaris terminal position is move down along with the age growth(P<0.05).Conclusions:The end position of conus medullaris of adults can be below the level of L2-3 levels.The choice of L2-3 intervertebral space for lumbar anesthesia can make the risk of spinal cord injury.There is a significant correlation between the end position of conus medullaris and the nationality,gender and age of adults,and the differences should be considered in clinical intraspinal anesthesia.