The Decussating Fibers of the Lumbar Thoracolumbar Fascia: A Landmark for Identifying the L5 Spinous Process?

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Publication Date


Publication Title

World Neurosurg


Aged; Aged, 80 and over; Anatomic Landmarks; Cadaver; Fascia; Humans; Lumbar Vertebrae; Neurosurgical Procedures


BACKGROUND: The thoracolumbar fascia (TLF) has been well studied and is known to have crisscrossing fibers. Based on surgical experience, we hypothesized that the decussating fibers of the TLF may indicate a specific vertebral level and performed an anatomic study.

METHODS: Twenty adult fresh frozen cadavers aged 72-84 years at death were placed in the prone position, and the skin of the lumbar and upper sacrum was removed. Careful attention was given to the TLF and any fibers of it that grossly crossed the midline to interdigitate with its contralateral counterpart. Once such decussations were identified, a metal wire was laid on them at their center, and fluoroscopy was performed to verify the vertebral level.

RESULTS: Decussating fibers of the TLF were found on all but 1 specimen (95%). The central part of the decussation on the midline corresponded to the spinous process of L5 in 17/19 (89%) of specimens and the lower edge (L4-L5 interspace) of the spinous process of L4 in the remaining 2 specimens (11%). No specimens were found to have previous surgery in the area dissected or congenital anomalies of the spine.

CONCLUSIONS: In our cadaveric study, the decussating fibers of the TLF in the lumbar region helped predict the L5 spinous process in 89% of specimens and the L4 spinous process in 11% of specimens. This anatomic landmark might be used as an adjunct to palpation and intraoperative imaging during surgical exploration of the lower lumbar region.

Clinical Institute

Neurosciences (Brain & Spine)