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

Abstract

Aim. To determine the level of the conus medullaris-Tuffier's line, and conus medullaris-Tuffier's line distance using imaging and evaluate their relation to age and gender. Methods. We performed a cross-sectional study of 189 adult participants, who underwent MR imaging of lumbosacral spine. Each vertebra was divided into 3 equal segments (upper, middle, and lower), and intervertebral disc space was also assumed as one segment. All segments from T12 upper segment to L5S1 intervertebral disc were numbered consecutively. The position of conus medullaris and Tuffier's line was determined by the vertebral segment or intervertebral disc space at the same level. The patients were stratified into high/low conus medullaris position (cutpoint: L1 middle segment) and short/long conus-Tuffier's distance (cutpoint: 14 segments). Results. Women with low conus were significantly more than men, in patients older than 50 years old (72.7% in females versus 55.3% in males; P < .05), whereas there was not such a sexual dimorphism in patients younger than 50 years old. Similarly, short conus-Tuffier's distance was more frequent among women than men in patients older than 50 years old (59.7% in females versus 39.5% in males; P < .05), whereas there was not any gender difference in patients younger than 50 years old. Conus-Tuffier's distance was negatively correlated with age (r = −0.32, P < .001) in all studied population. Conclusion. Anatomical landmarks vary according to age and gender, with a lower end of conus medullaris in women, so clinicians should use more caution on the identification of the appropriate site for lumbar puncture, particularly in elderly women.

The influence of age on positions of the conus medullaris, Tuffier's line, dural sac, and sacrococcygeal membrane in infants, children, adolescents, and young adults

“…These results are consistent with those of a study of 145 neonates using ultrasound; it reported that the termination of the spinal cord was at a median level of L2 (12). A recent study demonstrated a lower level of conus medullaris in women, especially in elderly women (13). However, there was no difference between male and female in our study group.…”

Radiological Evaluation of the Tuffier’s Line in Pediatric Patients

“…Perhaps this has been the inspiration for many studies however despite being more studies are conducted in the adult population, studies in the pediatric age group are not sufficiently available. MR imaging studies demonstrated that the Tuffier's line were in a significantly lower position in females compared to males in adults [4,8]. A similar result demonstrated by Windisch et al in a cadaveric study [9].…”

Are high lumbar punctures safe? A magnetic resonance imaging morphometric study of the conus medullaris

“…Most cadaveric studies show variability in CM position but it most commonly terminates at L1-L2 in adults (Saifuddin et al, 1998). Other studies demonstrate that the CM position is rarely below L2-L3 in normal cases (Tubbs and Oakes, 2004;Rahmani et al, 2011). Previous studies in supine patients using midsagittal lumbar spine magnetic resonance imaging (MRI) revealed the average CM termination position at the lower third of the L1 vertebral body, with a range from mid T12 to upper L3 (Boon et al, 2004).…”