Safety Considerations When Dry Needling the Multifidi in the Thoracolumbar Region: A Cadaveric Study.

Background: Dry needling the lumbar multifidi is a technique used by physical therapists to effectively treat low back pain. While studies have examined the safety considerations in the upper lumbar spine related to the kidneys and lungs, none have investigated the possibility of entering the spinal canal in this region. Purpose: The purpose of this cadaveric ultrasound-guided dry needling exploration was to determine if a dry needle can penetrate the ligamentum flavum at the T12/L1 interspace and enter the spinal canal using a paramedian approach in a fresh-frozen, lightly fixed cadaver in the prone position. Study Design: Cadaveric study. Methods: The procedure was performed on a cadaver in the prone position. The needle was advanced under ultrasound guidance to determine if a 0.30 x 50 mm dry needle inserted 1.0 cm lateral to the spinous process of T12 and directed medially at a 22-degree angle could penetrate the ligamentum flavum and enter the spinal canal. Results: As determined via ultrasound, a dry needle can penetrate the ligamentum flavum and enter the spinal canal at the thoracolumbar junction using this technique. Conclusion: This interprofessional collaboration demonstrates that a dry needle can penetrate the ligamentum flavum to enter the spinal canal at T12/L1 using a documented technique for dry needling the multifidus. A thorough understanding of human anatomy along with the incorporation of available technology, such as ultrasound, may decrease the risk of adverse events when dry needling the multifidi at the thoracolumbar junction. Level of Evidence: Level IV.

Intrathecal Spread of Injectate Following an Ultrasound-Guided Selective C5 Nerve Root Injection in a Human Cadaver Model.

Ultrasound-guided selective C5 nerve root blocks have been described in several case reports as a safe and effective means to anesthetize the distal clavicle while maintaining innervation of the upper extremity and preserving diaphragmatic function. In this study, cadavers were injected with 5 mL of 0.5% methylene blue dye under ultrasound guidance to investigate possible proximal and distal spread of injectate along the brachial plexus, if any. Following the injections, the specimens were dissected and examined to determine the distribution of dye and the structures affected. One injection revealed dye extended proximally into the epidural space, which penetrated the dura mater and was present on the spinal cord and brainstem. Dye was noted distally to the divisions in 3 injections. The anterior scalene muscle and phrenic nerve were stained in all 4 injections. It appears unlikely that local anesthetic spread is limited to the nerve root following an ultrasound-guided selective C5 nerve root injection. Under certain conditions, intrathecal spread also appears possible, which has major patient safety implications. Additional safety measures, such as injection pressure monitoring, should be incorporated into this block, or approaches that are more distal should be considered for the acute pain management of distal clavicle fractures.

Ultrasound-Guided Ankle Blocks: A Review of Current Practices.

Ankle blocks are routinely indicated for surgical anesthesia and postoperative analgesia of procedures involving the foot. Traditionally, ankle blocks have been performed by relying on landmark identification of nerves. The literature regarding the performance and efficacy of ankle blocks is inconsistent. This can be attributed to several variables, such as provider technique, differences in patient populations, and the type and volume of local anesthetics administered. As with other peripheral nerve blocks originally performed using landmark technique, ultrasound imaging is now being incorporated into these procedures. Ultrasound guidance provides the anesthetist with several advantages over landmark techniques. The ability to identify peripheral nerves, view needle movements in real-time, and observe the spread of local anesthetic has been shown to result in greater block efficacy, even with reduced volumes of local anesthetic. Additionally, ultrasound imaging gives the provider the option to perform regional anesthesia in specific patient populations not considered possible when using landmark technique. Despite the limited literature on ultrasound-guided ankle blocks, outcome metrics seem to be consistent with those of other peripheral nerve blocks performed using this technology.