Evaluating the Reliability of Anatomic Landmarks in Safe Lumbar Puncture Using Magnetic Resonance Imaging: Does Sex Matter?

Table 1

Primary characteristics of participants.

	Male (𝑛=72)	Female (𝑛=117)	Total (𝑛=189)
Age (yrs, SD)	50.1 (4.1)	52.3 (5.2)	51.9 (4.8)
Conus-position	L1m* (T12u-L2m)	L1u (T12u-L2u)	L1u (T12u-L2m)
Tuffier’s line position	L4L5 IVD**; (L3L4 IVD-L5S1 IVD)	L5m; (L4m-L5S1 IVD)	L5u; (L3L4 IVD-L5S1 IVD)
Conus-Tuffier’s distance (no. of segments)	15 (9–21)	15 (10–20)	15 (9–21)
Younger than 50	34	40	74
Low conus	16 (47%)	15 (37%)	31 (41%)
Short conus-Tuffier’s distance	14 (41%)	15 (37%)	29 (39%)
Older than 50 years	38	77	115
Low conus	21 (55.3%)*	56 (72.5%)	77 (67%)
Short conus-Tuffier’s distance	15 (39.5%)*	46 (59.7%)	61 (53.0%)

Variables are expressed as mean (SD), median (interquartile range) or number and percent. *𝑃<.05,**𝑃<.01 when comparing women with men. U stands for upper segment; m stands for middle segment; l stands for lower segment; IVD stands for intervertebral disc. Low conus: conus medullaris position lower than middle L1 vertebra; short conus-Tuffier’s distance: conus-Tuffier’s distance equal and less than L4 segments.