A New Solution to an Old Problem: Ultrasound-guided Cervical Retrolaminar Injection for Acute Cervical Radicular Pain: Prospective Clinical Pilot Study and Cadaveric Study

Study Design.Prospective clinical pilot study and cadaveric study.Objective.The aim of this study was to evaluate the spread of an ultrasound-guided interfascial plane blocks (UGIPBs) and its potential efficacy for cervical radiculopathy.Summary of Background Data.Cervical radiculopathy is a common disorder, potentially leading to severe pain and disability. Conservative treatment with cervical epidural steroid injections (ESI) is limited by concerns regarding their safety. UGIPBs are used in cervical surgical procedures as part of the multimodal postoperative analgesia regimen however, were not described for cervical radiculopathy.Methods.Twelve patients with acute cervical radicular pain who failed conservative treatment and were candidates for surgery were offered a cervical retrolaminar injection. A solution of 4 mL lidocaine 0.5% and 10 mg dexamethasone was injected, assisted by ultrasound guidance, at the posterior aspect of the cervical lamina corresponding to the compressed nerve root level. Additionally, a cadaver study was carried to evaluate the contrast spread and infiltration into near structures, both anatomically and radiographically.Results.Twelve patients underwent the procedure, with a mean follow-up time of 14.5 weeks. Average numerical rating scale improved from 7.25 at baseline to 2.83 following the injection (P < 0.001). Three patients received 2 to 3 injections without significant improvement and were eventually operated. No adverse events were reported.In the cadaver study, fluoroscopy demonstrated contrast spread between T1 and T3 caudally, C2 to C5 cranially and facet joints laterally. Anatomically, the dye spread was demonstrated up to C2 cranially, T1 caudally, the articular pillars of C4 to C7, and the neural foramen of C6 laterally.Conclusion.A solution injected into the cervical retrolaminar plane can diffuse in the cranial-caudal axis to C2-T3 and laterally to the facet joints and the cervical neural foramen. Our pilot study confirmed the feasibility of our study protocol. Future studies are needed to support our early results.Level of Evidence: 4.