Ultrasound-Guided versus Landmark-Guided Lumbar Facet Joint Injections in Patients with Chronic Low Back Pain: A Randomized Controlled Trial

INTERVENTION: Group 1: Ultrasound‐guided facet joint injection: Lumbar facet joint injection is performed under real‐time ultrasound guidance. Following sonographic identification of the relevant lumbar anatomical structures, a 22‐gauge spinal needle is advanced in‐plane toward the target facet joint. After reaching the target region, a standardized mixture of 1 mL 0.5% bupivacaine and 1 mL triamcinolone acetonide 40 mg is administered per treated facet joint. Follow‐up is performed for 6 weeks. Group 2: Landmark‐guided facet joint injection: Lumbar facet joint injection is performed using palpation‐based surface anatomical landmarks without imaging guidance. The insertion point is determined using the spinous processes, interspinous spaces, and surface anatomical orientation. The same standardized mixture of 1 mL 0.5% bupivacaine and 1 mL triamcinolone acetonide 40 mg is administered per treated facet joint. Follow‐up is performed for 6 weeks. CONDITION: Chronic axial low back pain associated with lumbar facet syndrome and degenerative lumbar facet joint changes PRIMARY OUTCOME: Requirement for needle repositioning during lumbar facet joint injection. During the procedure, it is recorded whether repositioning or redirection of the needle after initial needle placement is required to reach the intended anatomical target region. The endpoint is documented immediately during the procedure as a binary variable (needle repositioning: yes/no). SECONDARY OUTCOME: Secondary outcomes are: (1) procedure duration in minutes, assessed during the intervention; (2) pain intensity measured using the Numeric Rating Scale (NRS, 0–10) at baseline and at 1 and 6 weeks; (3) change in NRS pain intensity from baseline; (4) time to clinically meaningful pain relief, defined as a reduction of at least 2 NRS points from baseline during the 6‐week follow‐up period; and (5) peri‐interventional complications or adverse events during the study period. INCLUSION CRITERIA: Chronic axial low back pain with clinical suspicion of lumbar facet joint syndrome; clinical and radiological findings consistent with lumbar facet joint involvement; indication for lumbar facet joint injection; ability to understand the study information and provide written informed consent.