Ultrasound-guided procedures for the management of chronic thoracic back pain: a technical review.

Pain arising from the thoracic region has been reported to be potentially as debilitating as cervical or lumbar back pain, and may stem from a vast number of spinal sources, including zygapophysial, costovertebral and costotransverse joints, intervertebral discs, ligaments, fascia, muscles, and nerve roots. Over the last two decades, the use of ultrasound in interventional spinal procedures has been rapidly evolving, due to the ultrasound capabilities of visualizing soft tissues, including muscle layers, pleura, nerves, and blood vessels, allowing for real-time needle tracking, while also reducing radiation exposure to both patient and physician, when compared to traditional fluoroscopy guidance. However, its limitations still preclude it from being the imaging modality of choice for some thoracic spinal procedures, notably epidural (interlaminar and transforaminal approaches) and intradiscal injections. In this technical review, we provide an overview of five thoracic spinal injections that are amenable to ultrasound guidance. We start by discussing their clinical utility, followed by the relevant topographic anatomy, and then provide an illustrated technical description of each of the procedures discussed: (1) erector spinae plane block; (2) intra-articular thoracic zygapophyseal (facet) joint injection; (3) thoracic medial branch block; (4) costotransverse joint injection; and (5) costovertebral joint injection.

Ultrasound-guided costovertebral joint injection-technique description and fluoroscopy and computerized tomography combined controlled cadaveric feasibility study.

OBJECTIVES: To describe and assess the feasibility of an ultrasound-guided technique for intra-articular injection of the costovertebral joints, in an unembalmed cadaveric specimen, utilizing fluoroscopy and cone beam computerized tomography for confirmation of contrast spread and needle tip position, respectively. METHODOLOGY: A single unembalmed cadaveric specimen was obtained. A single interventionist performed the placement of the needles under ultrasound guidance. Contrast dye was then injected through each of the needles under real-time fluoroscopy. Finally, the specimen was submitted to a cone beam computerized tomography with 3-dimensional acquisition and multiplanar reformatting to assess final needle tip position relative to the costovertebral joints. RESULTS: In total, 18 spinal needles were placed under ultrasound guidance. Fluoroscopy showed 4 distinct patterns of contrast spread: intra-articular in the costovertebral joint (13 levels in total), epidural (1 level), intra-articular in the facet joint of the target level (3 levels), and undetermined (1 level). Cone-beam computerized tomography confirmed 13 out of 18 needles to be adequately placed in the costovertebral joints (72% of the total) and 5 out of the 18 needles to be misplaced: 3 needles were placed in the facet joint of the target level, and 2 needles were placed in the epidural space. CONCLUSIONS: This study suggests that, when performed by experienced interventionists, this technique has an accuracy rate of 72%. Further studies are warranted before these results can be extrapolated to daily clinical practice.