Geometrical Dimensions and Morphological Study of the Lumbar Spinal Canal in the Normal Egyptian Population

Abstract

Information regarding the precise dimensions of the lumbar vertebrae is essential for spinal surgery and instrumentation. When stenosis of the vertebral canal or the intervertebral foramen exists, the neural structures in them can be affected and cause symptoms such as low back or radicular pain. Accurate and comprehensive spinal canal measurements in the lumbar vertebrae are incomplete. The purpose of this study was to collect data on the dimensions of the lumbar spinal canal from computed tomography scans. Three hundred patients (162 men and 138 women) were studied. Computed tomography scans were obtained to determine the normal values of the midsagittal diameter, interpedicular distance, and lateral recess depth in the normal Egyptian population. The narrowest level was L3. The range of the midsagittal diameter was 11.07 to 26.07 mm at all levels. The range of the interpedicular distance was 17.00 to 43.41 mm at all levels. In all patients at all levels, mean lateral recess depth was 6.7 mm (range, 4-14 mm). The narrowest lateral recess depth was at L5. Few patients (3.3%) had a statistically stenotic midsagittal diameter measurement. The canal shape was not uniform along the 5 lumbar vertebrae; it ranged from being circular or rounded in the upper lumbar vertebrae to triangular in the midlumbar vertebrae to trefoil in the lower lumbar vertebrae, especially at L5. Trefoil canals existed mainly in the lower lumbar vertebrae at L5, followed by L4. Data from computed tomography scans combined with accurate measurements are the basis for anatomical studies, clinical research, and the development of implants suitable for a group of patients with measurements different from the population standard.

Normative dimensions of lumbar canal and dural sac by computer tomography in Togo

“…Concerning the IPD, our study showed a progressive increase from L1 to L5. Tarek et al [6] and Ongolo Zogo et al [9] found respectively in Egyptians and in Cameroonians similar results. On the other hand, El-Rakhawy et al [8] noticed an average IPD almost identical at the level of the four first lumbar vertebrae (≈ 24mm) followed by an increase in L5 (28.48mm).…”

“…The lower value was found in L3. The same remark was made by Amonoo-Kuofi et al [5] in Nigeria, by Tarek Aly et al [6] in Egypt, and by Lee et al [7] in Corea. The high APD in L1 and L2 could be explained by the bulge of the conus medullaris at this level.…”

“…On the other hand, El-Rakhawy et al [8] noticed an average IPD almost identical at the level of the four first lumbar vertebrae (≈ 24mm) followed by an increase in L5 (28.48mm). The comparison of the IPD between our study and those of Ongolo Zogo et al [9] in Cameroon, of Amonoo-Kuofi et al [12] in Nigeria, of Tarek et al [6] in Egypt, of El-Rakhawy M et al [8] in Pakistan did not show any significant difference statistically. But on the other hand, the studies of Postachini et al [13] and of Piera et al [14] showed that the IPD would be different across populations.…”

“…The same remark was made by El-Rakhawy et al [8] in Pakistan. The comparison of the dimensions of our study with those of Amonoo-Kuofi et al [5] in Nigeria, of Ongolo Zogo et al [9] in Cameroon, of Tarek et al [6] in Egypt, and of El Rakhawy et al [8] in Pakistan and with that of Getroa [10] in Belgium did not find significant difference statistically. But our study found significant difference statistically in APD1 measurements with the study of Lee et al [7] in Korea.…”

“…The study of El-Rakhawy et al [8] in Pakistan found higher values in L4 and L5 and the lowest value in L3. Thus, many studies [5][6][7][8] agree on the fact that the smallest measurement of the APD is in L3. Statistically, there was no significant difference of the APD between male and female in our study.…”