Inferior-Medial Dry Needling at the Thoracolumbar Junction: A Cadaveric Study.
Christi L Williams, Sue E Curfman, Stacey R Lindsley and 2 others
PMID 39371194WHAT IT FOUND
A 40 mm needle inserted 1.9 cm lateral to the T12 spinous process penetrated the spinal canal on the fourth attempt in a single cadaver.
This confirms a theoretical risk of spinal entry with inferior-medial dry needling but does not prove it happens in patients.
Key findings
01A 0.30 x 40 mm dry needle was able to traverse the space between the vertebral laminae of T12 and L1, penetrate the ligamentum flavum, and enter the spinal canal on the fourth attempt.
02The needle that entered the spinal canal was located 1.9 cm lateral to the spinous process of T12, with a medial angulation of 33 degrees from vertical and an inferior angulation of 18 degrees.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
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What it does not show
The study used only one cadaver, so it cannot determine how often this happens in living patients or how variable anatomy is between people. Cadaver tissue differs from living tissue in stiffness and turgor, which may affect how a needle travels through the ligamentum flavum. The donor was 77 years old and likely had disc degeneration, which can thicken and stiffen the ligamentum flavum, potentially making it harder for a needle to penetrate than in a younger patient. The center of the spinous process was identified by palpation rather than imaging or dissection, so the exact location measurements may not be precise.
Declared interests
No conflicts of interest or funding sources are stated in the provided text.
The easy way to misread this
Do not assume that dry needling the multifidi at the thoracolumbar junction is unsafe or that a specific needle angle causes spinal injury in patients. This single cadaver study only shows that penetration is physically possible, not that it occurs with any frequency in clinical practice.