Ultrasound-guided selective nerve root block versus fluoroscopy-guided transforaminal block for the treatment of radicular pain in the lower cervical spine: a randomized, blinded, controlled study

Abstract

Objectives: To compare the short-term effects and advantages of ultrasound-guided selective nerve root block with fluoroscopy-guided transforaminal epidural block for radicular pain in the lower cervical spine through assessment of pain relief, functional improvement, and safety.

Methods: A total of 120 patients with radicular pain from cervical spinal stenosis or cervical herniated disc were enrolled. All procedures were performed using a fluoroscopy or ultrasound apparatus. The subjects were randomly assigned to either the fluoroscopy (FL) or ultrasound (US) group. The complication frequencies during the procedures, treatment effects, and functional improvement of the nerve root block were compared at 2 and 12 weeks after the procedures.

Results: Verbal Numeric Pain Scale (VNS) improved 2 weeks and 12 weeks after the injections in both groups. Statistical differences were not observed in VNS, Neck Disability Index (NDI), and effectiveness between the groups. In 21 patients at US, vessels were identified at the anterior aspect of the foramen. Eleven patients had a critical vessel at the posterior aspect of the foramen and five patients had on artery continue medially into the foramen, forming, or joining a segmental feeder artery. In both cases, the vessels might well have been in the pathway of the needle correctly positioned under fluoroscopic guidance. Five cases of intravascular injections were observed only in FL without significant difference between the groups.

Conclusions: The US-guided method may facilitate identifying critical vessels at unexpected locations relative to the intervertebral foramen and avoiding injury to such vessels, which is the leading cause of the reported complications from cervical transforaminal injections. On treatment effect, using either method of epidural injections to deliver steroids for cervical radicular pain, secondary to herniated intervertebral disc or foraminal stenosis, significant improvements in function and pain relief were observed in both groups after the intervention. However, significant difference was not observed between the groups. Therefore, the ultrasound-guided method was shown to be as effective as the fluoroscopy-guided method in pain relief and functional improvement, in addition to the absence of radiation and avoiding vessel injury at real-time imaging.