Ultrasound-Guided Lumbar Facet Nerve Block

Facet joint–mediated pain has been identified as a frequent cause of low back pain but cannot be diagnosed by clinical examination or radiographic imaging.

A controlled series of lumbar facet nerve blocks, selectively anesthetizing the medial branch of the dorsal primary ramus of the spinal nerve innervating the facet joint, is the accepted standard to diagnose facet joint– mediated pain today. To ensure success and to avoid complications such as inadvertent spinal anesthesia, facet nerve blocks are currently performed under fluoroscopic or computed tomography scan guidance, which is inevitably associated with x-ray exposure, problems with device availability, and higher cost. Ultrasound, in contrast, is a portable, moderately priced imaging modality and is not associated with exposure to radiation. The current role of ultrasound guidance for regional anesthesia has been summarized recently. So far, ultrasonography has been used for guidance in a broad spectrum of different nerve blocks and is available for guided lumbar facet nerve block.

Ultrasonography has absolutely no exposure to radiation for the patient and the practitioner is a clear potential advantage of the ultrasound technique, making it principally applicable also during pregnancy. Although the amount of radiation for fluoroscopy-guided blocks may be small and the effect on patient–practitioner mortality and morbidity unclear, elimination of radiation for any procedure is desirable, especially if is not so small, as during computed tomography scan guidance. Moreover, compared with fluoroscopy or computed tomography scanning, ultrasound is only moderately priced and offers more flexibility.