The Interlaminar and the Narrowest Distances at the L3/4 and L4/5 Interspinous Spaces and Location of the Intercrestal Line in Thai Cadavers
Kajorn Lakchayapakorn MD*, Nadthaganya Suwanlikhid MSc*
Affiliation : * Division of Anatomy, Department of Preclinical Science, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Background : Data on the L3/4 and L4/5 interspinous distances are important in performing a lumbar puncture. This has not
been studied in Thais.
Objective : To study the interlaminar and the narrowest distances at the L3/4 and L4/5 interspinous spaces and location of the
intercrestal line in Thai cadavers.
Material and Method: The interlaminar and the narrowest distances at the L3/4 and L4/5 interspinous spaces and location
of the intercrestal line were measured in 87 cadavers. Mean age of cadavers was 66.7+10.6 years (range 40-80 years).
Measurements were statistically analyzed using unpaired t-tests.
Results : The intercrestal line most often intersected at the lower half of the L4 spinous process (32/87, 36.8%), ranging from
the lower half of L3 spinous process to the upper half of S1. Mean interlaminar and the narrowest distances at the L3/4
interspinous space were not significantly different from the L4/5 interspinous space: 7.32+2.7 mm vs. 7.05+3.0 mm and
5.27+2.1 mm vs. 5.38+2.4 mm, respectively (p>0.05). These interspinous process distances in 71-80 year old cadavers were
significantly shorter than 40-60 and 61-70 year age groups (p<0.05).
Conclusion : The present study confirms that the intercrestal line is most commonly at the lower half of the L4 spinous
process. Mean interlaminar and the narrowest distances at the L3/4 and L4/5 interspinous spaces were unrelated to gender
or body type. The elderly had more narrow interspinous process distances which may be benefit from having lumbar puncture
done in the sitting and feet supported position.
Keywords : Lumbar puncture, Lumbar vertebra, Lumbar spine, Intercrestal line, Interspinous space
