Lumbar spinal stenosis is a common cause of neurogenic claudication and functional limitation in older adults. Epidural steroid injections are frequently used in patients who do not respond to conservative treatments. The erector spinae plane block has recently emerged as a potential alternative interventional technique for pain control in lumbar spine disorders.

This prospective comparative study will evaluate and compare the effectiveness of erector spinae plane block and caudal epidural steroid injection in patients with lumbar spinal stenosis refractory to conservative treatment. Clinical outcomes including pain intensity, functional status, and walking capacity will be assessed at predefined follow-up intervals.

The study aims to determine whether erector spinae plane block provides comparable or superior clinical benefit compared with caudal epidural steroid injection in this patient population.

This prospective, randomized, parallel-group comparative study was conducted to evaluate the clinical effectiveness of ultrasound-guided lumbar erector spinae plane block compared with fluoroscopy-guided caudal epidural steroid injection in patients with lumbar spinal stenosis refractory to conservative treatment.

Eligible participants were randomized into two intervention arms. Patients in the erector spinae plane block group received a lumbar 4 level ultrasound-guided injection of local anesthetic administered under sterile conditions. Patients in the caudal epidural steroid injection group received a fluoroscopy-guided caudal epidural injection consisting of corticosteroid and local anesthetic according to institutional protocol.

The primary outcome measure was pain intensity assessed using the Visual Analog Scale (VAS) for leg pain. Assessments were performed before the procedure, 1 hour after injection, and at 4 and 8 weeks following the intervention.

Secondary clinical evaluations included functional status and walking capacity assessed at predefined follow-up intervals.

The study was approved by the local ethics committee, and written informed consent was obtained from all participants prior to enrollment.

Inclusion Criteria:

Inclusion Criteria

• Age between 30 and 80 years
• Patients with chronic low back pain (lasting longer than 6 months)
• Diagnosis of lumbar spinal stenosis (LSS) confirmed by imaging modalities (CT/MRI) and clinical evaluation
• LSS Diagnostic Support Tool Assessment (LSS-DST) score greater than 7
• Patients who did not benefit from previous conservative treatments
• Presence of a signed written informed consent form indicating willingness to participate in the study

LSS-DST (Lumbar Spinal Stenosis - Diagnostic Support Tool) Scoring System

• Age 60-70 years: +1 point
• Age over 70 years: +2 points
• Absence of Diabetes Mellitus: +1 point
• Positive claudication: +3 points
• Symptoms aggravated by standing: +2 points
• Symptoms relieved by forward flexion: +3 points
• Symptoms induced by forward flexion: -1 point
• Symptoms induced by lumbar extension: +1 point
• Ankle-brachial index ≥ 0.9: +3 points
• Abnormal Achilles tendon reflex: +1 point
• Positive straight leg raise test: -2 points

Exclusion Criteria:

History of lumbar epidural steroid injection within the last 6 months or history of major trauma

• Known allergy to the study medications (lidocaine hydrochloride, dexamethasone 21-phosphate) or to contrast agents
• Presence of unstable chronic medical conditions (e.g., diabetes mellitus, hypertension, chronic obstructive pulmonary disease, heart failure)
• Advanced joint limitations preventing mobilization (e.g., hip or knee osteoarthritis)
• History of previous lumbar spine surgery
• Current anticoagulant therapy or history of coagulopathy
• History of malignancy
• History of polyneuropathy
• Presence of peripheral vascular disease
• Psychiatric disorders or cognitive impairment that would interfere with completion of questionnaires and assessment scales (including significant visual or hearing impairment)
• Presence of local or systemic infection at the intended injection site
• Pregnancy and/or breastfeeding
• Refusal or inability to provide informed consent