Abstract:
The spine of L4 usually lies on a line drawn between the highest points of the
iliac crests (Tuffier’s line) in adults. Although its accuracy has been questioned, it
is still commonly used to identify the spinous process of the 4th lumbar vertebra
before performing lumbar neuraxial procedures. In children, this line is said to
cross the midline at the level of L5. A literature search revealed that the
description this surface anatomical line is vague in neonates. The aims of this
study were to determine the vertebral level of Tuffier’s line, as well as its distance
from the apex of the sacrococcygeal membrane (ASM), in 39 neonatal cadavers
in both a prone and flexed position. It was found that when flexed, Tuffier’s line
shifted from the level of L4/L5 (prone position) to the upper third of L5. The mean
distance from the ASM to Tuffier’s line was 23.64mm when prone and 25.47mm
when flexed, constituting a statistically significant increase in the distance
(p=0.0061). Therefore, in the absence of advanced imaging modalities, Tuffier’s
line provides practitioners with a simple method of determining a level caudal to
the termination of the spinal cord, at approximately the L4/L5 in a prone neonate
and the upper margins of L5 when flexed.
