Anatomic morphological study of thoracolumbar foramen in normal adults

BACKGROUND: Based on computed tomography images of the thoracolumbar intervertebral foramen and its surrounding parameters, and analysing the intervertebral foramen morphology and the correlation between the measured parameters, to provide an anatomical basis for clinical minimally invasive transvertebral surgery. MATERIALS AND METHODS: Ten fresh adult cadaveric specimens (32-50 years old) with bilateral (T1-S1) spinal segments were selected for a total of 20 sides, a total of 340 intervertebral foramens and were measured with vernier callipers in the Department of Anatomy, Inner Mongolia Medical University. The intervertebral foramen height, the minimum sagittal diameter of the foramen, the width of the spinal ganglion, the sagittal diameter of the spinal ganglion and the sagittal diameter of the intervertebral foramen were measured. This study was reviewed and approved by the local Ethics Committee. RESULTS: The results of the minimum sagittal diameter of the T9-10~L5/S1 intervertebral foramen were (6.93 ± 1.99) mm, (7.33 ± 1.44) mm, (7.41 ± 0.63) mm, (6.85 ± 1.08) mm, (6.79 ± 1.86) mm, (7.82 ± 3.25) mm, (8.23 ± 2.27) mm, (9.17 ± 2.33) mm, (8.38 ± 1.63) mm; the average height of the T2/3 to L5/S1 intervertebral space was (4.82 ± 1.88) mm, (3.95 ± 0.80) mm, (4.04 ± 0.52) mm, (4.26 ± 0.78) mm, (4.39 ± 1.16) mm, (5.15 ± 1.59) mm, (5.51 ± 1.49) mm, (5.97 ± 2.60) mm, (7.13 ± 2.07) mm, (8.94 ± 1.37) mm, (9.01 ± 1.47) mm, (11.63 ± 1.63) mm, (14.20 ± 1.37) mm, (14.22 ± 2.33) mm, (14.22 ± 2.33) mm, (13.32 ± 1.37) mm intervertebral foramen height, intervertebral foramen minimum sagittal diameter, spinal ganglion width, spinal ganglion sagittal diameter. P > 0.05 for comparison of the left and right sides of the intervertebral space, with no statistically significant difference. L4/5, L5/S1 segment left and right bilateral contrast with the middle height of the vertebral space p < 0.05, the difference is statistically significant. The remaining segments left and right bilaterally contrasted p > 0.05, and the difference was not statistically significant. CONCLUSIONS: The minimum height of intervertebral foramen in the thoracolumbar segment was T6/7, and L1/2 was the minimum height in the lumbar segment. When placing a spinal endoscopic working channel safely into intervertebral foramen, it is necessary to perform an enlarging foraminoplasty to reduce the risk of injury to the exiting nerve root.