Dimensions of the lumbar spinal canal: variations and correlations with somatometric parameters using CT

The aim of this study was to investigate the correlation of vertebral dimen sions with somatometric parameters in patients without clinical symptoms an d radiological signs of central lumbar spinal stenosis. One hundred patient s presenting with low back pain or sciatica were studied with CT. In each o f the L3, L4 and L5 vertebra three slices were taken with the following mea surements: 1. Slice through the intervertebral disc: (a) spinal canal area; (b) interarticular diameter; (c) interligamentous diameter. 2. Slice below the vertebral arcus; (a) dural sac area; (b) vertebral body area. 3. Pedic ulolaminar level: (a) anteroposterior diameter and interpedicular diameter of the spinal canal; (b) spinal canal area; (c) width of the lateral recess es. The Jones-Thomson index was also estimated. The results of the present study showed that there is a statistically significant correlation of heigh t, weight and age with various vertebral indices. The conventional, widely accepted, anteroposterior diameter of 11.5 mm of the lumbar spinal canal is independent of somatometric parameters, and it is the only constant measur ement for the estimation of lumbar spinal canal and correlations with heigh t, weight and age of the patient.