Table 2.
Parameters of the lumbar safety triangle and dorsal root ganglion, in the coronal plane on the right side, by sex and age group, at the different levels of the lumbar spine.
| Parameter | Total sample (N = 210) Mean ± SD (range) | Sex | Age group | |||||
|---|---|---|---|---|---|---|---|---|
| Female (n = 120) Mean ± SD | Male (n = 90) Mean ± SD | p* | 18–39 years (n = 75) Mean ± SD | 40–65 years (n = 116) Mean ± SD | 66–98 years (n = 19) Mean ± SD | p† | ||
| At L2–L3 | ||||||||
| Lumbar safety triangle | ||||||||
| Height, mm | 14.9 ± 2.7 (8.6–22.6) | 14.5 ± 2.7 | 15.4 ± 2.7 | 0.017 | 14.5 ± 2.8 | 15.2 ± 2.7 | 14.7 ± 2.1 | 0.254 |
| Base, mm | 11.8 ± 2.6 (6.8–19.3) | 11.5 ± 2.4 | 12.2 ± 2.8 | 0.069 | 11.1 ± 2.5a | 12.2 ± 2.6b | 12.0 ± 2.3a, b | 0.016 |
| Hypotenuse, mm | 15.5 ± 3.3 (7.3–23.7) | 15.0 ± 3.2 | 16.2 ± 3.3 | 0.009 | 15.0 ± 3.2 | 15.8 ± 3.4 | 15.7 ± 2.5 | 0.233 |
| Area, mm3 | 90.0 ± 32.7 (37.8–191.0) | 85.3 ± 29.3 | 96.4 ± 35.9 | 0.018 | 82.7 ± 31.5a | 95.0 ± 33.9b | 89.1 ± 25.0a, b | 0.038 |
| Dorsal root ganglion | ||||||||
| Largest dimension, mm | 6.1 ± 1.0 (3.3–9.2) | 5.9 ± 0.9 | 6.4 ± 1.1 | 0.002 | 6.1 ± 1.0 | 6.1 ± 1.0 | 6.2 ± 1.0 | 0.888 |
| Smallest dimension, mm | 5.0 ± 0.8 (3.1–7.0) | 4.8 ± 0.7 | 5.3 ± 0.9 | < 0.001 | 5.1 ± 0.8 | 5.0 ± 0.8 | 4.9 ± 0.6 | 0.600 |
| Invasion into the triangle, mm | 1.1 ± 0.2 (0.6–1.5) | 1.0 ± 0.2 | 1.1 ± 0.2 | 0.190 | 1.1 ± 0.2 | 1.1 ± 0.2 | 1.1 ± 0.2 | 0.886 |
| At L3–L4 | ||||||||
| Lumbar safety triangle | ||||||||
| Height, mm | 15.7 ± 2.6 (9.9–25.2) | 15.3 ± 2.6 | 16.2 ± 2.5 | 0.015 | 15.3 ± 2.8 | 15.9 ± 2.5 | 15.4 ± 1.8 | 0.286 |
| Base, mm | 12.2 ± 2.5 (6.9–19.5) | 11.8 ± 2.3 | 12.6 ± 2.7 | 0.028 | 11.6 ± 2.5 | 12.5 ± 2.6 | 12.1 ± 1.9 | 0.069 |
| Hypotenuse, mm | 16.2 ± 3.1 (8.6–23.8) | 15.7 ± 2.9 | 16.9 ± 3.2 | 0.007 | 15.5 ± 3.1 | 16.6 ± 3.2 | 16.5 ± 2.3 | 0.060 |
| Area, mm3 | 97.4 ± 32.8 (34.1–204.7) | 92.3 ± 30.0 | 104.2 ± 35.7 | 0.009 | 91.4 ± 33.4 | 101.8 ± 33.6 | 94.2 ± 21.2 | 0.093 |
| Dorsal root ganglion | ||||||||
| Largest dimension, mm | 6.4 ± 0.9 (4.2–9.6) | 6.2 ± 0.8 | 6.7 ± 1.0 | < 0.001 | 6.4 ± 0.9 | 6.5 ± 0.9 | 6.4 ± 1.0 | 0.983 |
| Smallest dimension, mm | 5.2 ± 0.8 (3.2–7.3) | 5.1 ± 0.7 | 5.4 ± 0.9 | 0.001 | 5.3 ± 0.8 | 5.2 ± 0.8 | 5.1 ± 0.7 | 0.714 |
| Invasion into the triangle, mm | 1.1 ± 0.2 (0.7–1.6) | 1.1 ± 0.2 | 1.2 ± 0.2 | 0.040 | 1.1 ± 0.2 | 1.1 ± 0.2 | 1.2 ± 0.1 | 0.736 |
| At L4–L5 | ||||||||
| Lumbar safety triangle | ||||||||
| Height, mm | 16.4 ± 2.6 (9.4–28.4) | 15.7 ± 2.3 | 17.3 ± 2.7 | < 0.001 | 16.3 ± 3.0 | 15.5 ± 2.5 | 16.1 ± 1.7 | 0.670 |
| Base, mm | 12.9 ± 2.3 (6.9–19.7) | 12.4 ± 2.1 | 13.5 ± 2.4 | 0.001 | 12.5 ± 2.3 | 13.2 ± 2.3 | 12.6 ± 2.0 | 0.155 |
| Hypotenuse, mm | 17.3 ± 3.0 (10.5–26.4) | 16.5 ± 2.8 | 18.3 ± 3.0 | < 0.001 | 17.0 ± 3.2 | 17.4 ± 2.9 | 17.2 ± 2.3 | 0.638 |
| Area, mm3 | 107.5 ± 32.8 (45.5–242.8) | 99.1 ± 27.8 | 118.6 ± 35.7 | < 0.001 | 104.1 ± 35.6 | 110.5 ± 32.2 | 102.1 ± 22.7 | 0.318 |
| Dorsal root ganglion | ||||||||
| Largest dimension, mm | 6.7 ± 1.0 (4.2–10.4) | 6.4 ± 0.8 | 7.0 ± 1.0 | < 0.001 | 6.7 ± 0.9 | 6.7 ± 1.0 | 6.6 ± 1.2 | 0.952 |
| Smallest dimension, mm | 5.3 ± 0.8 (2.9–8.4) | 5.2 ± 0.7 | 5.5 ± 0.9 | 0.003 | 5.4 ± 0.8 | 5.3 ± 0.8 | 5.2 ± 0.2 | 0.414 |
| Invasion into the triangle, mm | 1.2 ± 0.2 (0.6–1.8) | 1.2 ± 0.2 | 1.3 ± 0.2 | 0.010 | 1.2 ± 0.2 | 1.2 ± 0.2 | 1.2 ± 0.2 | 0.844 |
*Student’s t-test. †Analysis of variance with Bonferroni post-hoc analysis (different superscript letters in the same row indicate a statistically significant difference).