A radiographic assessment of the distances from the sacral hiatus to the lower lumbar spinous processes

The objective of this work is to determine whether the linear distances from the sacral hiatus to the lower lumbar spinous process are normally distributed when measured on Magnetic resonance images. In an observational study the distance from the sacral hiatus to the inferior border of the lower lumbar spinous processes was measured and analysed in sixty nine subjects on sagittal magnetic resonance images of the pelvis. Analysis of all distances with the Anderson-Darling Normality test showed the distances from the sacral hiatus to the 4th and 5th lumbar spinous processes to be normally distributed. The distances in males and females from the sacral hiatus to the fifth lumbar spinous process were 83.0 (13.7) mm and 71.0 (12.7) mm, respectively. The distances in males and females from the sacral hiatus to the fourth lumbar spinous process were 101.6 (14.2) mm and 92.2 (11.6) mm respectively. A significant inverse correlation between age and distance from the sacral hiatus to the 5th lumbar spinous processes was found in males in a magnetic resonance study. The distances from the sacral hiatus to the 4th and 5th lumbar spinous processes are normally distributed. These preliminary data may help to develop techniques to help prevent the neurological injury associated with neuraxial injections.