Inferior-Medial Dry Needling at the Thoracolumbar Junction: A Cadaveric Study

Area of Science:

• Anatomy
• Musculoskeletal Medicine
• Interventional Pain Management

Background:

• Dry needling (DN) is a common treatment for musculoskeletal pain.
• Serious adverse events, though rare, can occur with DN in spinal and thoracic areas.
• Safe techniques for DN in these vulnerable regions require further investigation.

Purpose of the Study:

• To determine if an inferior-medial multifidus DN technique can penetrate the ligamentum flavum (LF) and the spinal canal.
• To reproduce methods from Williams et al. with a modified DN approach.
• To assess needle trajectory and safety at the thoracolumbar junction.

Main Methods:

• A descriptive cadaveric study was conducted.
• A 0.30 x 40 mm dry needle was inserted 1.9 cm lateral to the T12 spinous process.
• Ultrasound guidance was used to direct the needle inferior-medially between T12 and L1 vertebral laminae.

Main Results:

• The dry needle successfully traversed the inter-laminar space.
• The needle penetrated the ligamentum flavum (LF).
• The needle entered the spinal canal with an inferior-medial angulation (33° medial, 18° inferior).

Conclusions:

• Dry needling is feasible for entering the spinal canal at the thoracolumbar junction using an inferior-medial technique.
• Ultrasound guidance can enhance the safety of DN training and clinical application.
• Findings are crucial for regions where DN safety concerns exist.