Cervical Retrolaminar Block Versus Cervical Epidural Injection for Cervical Radiculopathy

Overview

Cervical radiculopathy is a common clinical condition, affecting approximately 1 in 1,000 individuals each year, and is typically characterized by neck pain radiating to the upper extremities. Although about 90% of patients respond to conservative treatment, cervical epidural steroid injection is widely used as an interventional alternative to surgery in those with symptoms refractory to conservative management. However, concerns regarding the safety of cervical epidural steroid injection have increased in recent years. Ultrasound-guided cervical retrolaminar block, which does not require entry into the neuraxial space, is considered a theoretically safer technique. In this prospective, randomized study, 70 patients with cervical radiculopathy refractory to conservative treatment were enrolled and randomly assigned to receive either ultrasound-guided cervical retrolaminar block (n = 35) or fluoroscopy-guided cervical epidural steroid injection (n = 35). The study aimed to compare the clinical efficacy and safety of these two interventional approaches.

Cervical radiculopathy is the fourth leading cause of disability in the United States. In the general population, the lifetime risk of developing neck pain is approximately 50%. Cervical radiculopathy is a common clinical condition, often presenting with neck pain radiating to the upper extremities, with an annual incidence of approximately 1.79 per 1,000 individuals. The natural course of cervical radiculopathy tends toward spontaneous recovery in more than 90% of patients. First-line treatment options are generally non-surgical and include analgesics, cervical stabilizing exercises, traction, and physical therapy. In patients requiring surgery, the most frequently applied procedures are decompression with or without fusion. However, cervical spine surgery carries important risks and complications. Reported complication rates include surgical site infection (0.7-4%), dysphagia in more than 20% of patients, nerve root injury in up to 12%, and spinal cord injury in approximately 0.01%. Cervical epidural steroid injection is one of the most widely used cervical interventions and provides a non-surgical alternative. In patients refractory to conservative treatment but without progressive neurological deficit, cervical epidural steroid injections are commonly recommended. Nevertheless, there is currently no consensus on the optimal technique that best balances safety and efficacy. In recent years, paraneuraxial interfascial blocks performed under ultrasound guidance have gained popularity due to their anatomical and clinical advantages. Cervical retrolaminar block belongs to this group. In this technique, the injectate is administered between the lamina of C6 or C7 and the multifidus muscle, where there are no critical vascular or neural structures; for example, the deep cervical artery courses more laterally. A more medial approach may also reduce the risk of phrenic nerve paresis. In contrast, cervical epidural injections are less localized and may be associated with systemic side effects such as hypotension, urinary retention, and motor impairment. Ultrasound-guided cervical retrolaminar block offers several potential advantages, including technical simplicity due to clear bony landmarks, a lower risk of vascular injury, a reduced likelihood of phrenic nerve involvement or systemic adverse effects, and avoidance of radiation exposure. The hypothesis of this study was that ultrasound-guided cervical retrolaminar block is non-inferior to fluoroscopy-guided cervical epidural steroid injection in terms of pain relief and functional improvement in patients with cervical radiculopathy refractory to conservative treatment, while potentially offering a safer alternative. This trial was conducted as a prospective, randomized, controlled study at Istanbul Medeniyet University, Faculty of Medicine, Goztepe Prof. Dr. Suleyman Yalcin City Hospital. Written informed consent was obtained from all participants prior to enrollment, and the study was performed in accordance with international ethical standards and the Declaration of Helsinki. A total of 70 patients were included. Eligible participants were between 18 and 80 years of age, had MRI-confirmed cervical radiculopathy with a clearly identified affected level, and presented with pain intensity of at least 5 on the Visual Analog Scale (VAS) and an elevated Neck Disability Index (NDI) score. Additional inclusion criteria were absence of motor weakness, absence of signs or symptoms of myelopathy, and refractoriness to conservative treatments including manipulation, traction, physical therapy, and oral analgesics. Exclusion criteria included refusal to provide consent; coagulopathy; allergy or intolerance to local anesthetics; severe organ failure; pregnancy or lactation; cervical spine or adjacent soft tissue infection; inflammatory rheumatologic disease; fibromyalgia; neurological or neuromuscular disorders; demyelinating diseases; polyneuropathy; congenital malformations; prior cervical spine surgery; and comorbidities such as carpal tunnel syndrome, cubital tunnel syndrome, thoracic outlet syndrome, brachial plexus injury, or shoulder pathology. Patients who had previously received local corticosteroid injections, those using neuropathic pain agents (e.g., pregabalin, gabapentin), and those with cardiac pacemakers were also excluded. Patients were randomized into two groups. Group 1 (n = 35) received interlaminar cervical epidural steroid injection under fluoroscopic guidance, and Group 2 (n = 35) underwent ultrasound-guided cervical retrolaminar block. Randomization was performed using a sealed-envelope method. Following group allocation, all patients were informed about the assigned procedure and signed a standardized written informed consent form that detailed the study objectives, duration, interventions, and potential risks. Patient assessments included baseline and post-procedural evaluations using the Visual Analog Scale and the Neck Disability Index. Measurements were recorded at baseline (VAS-0, NDI-0) and at weeks 1 (VAS-1, NDI-1), 4 (VAS-4, NDI-4), 8 (VAS-8, NDI-8), and 12 (VAS-12, NDI-12). Additional recorded variables included patient age, sex, side of block application, need for surgery during follow-up, and adverse effects or complications related to the procedures or local anesthetics.