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Chapter Summary
• Context: Spine pain exhibits high global prevalence and significant recurrence rates, representing one of the major clinical challenges in orthopedic and neurosurgical practice. The advancement of interventional techniques transformed the management of axial and radicular spinal pain conditions, shifting from empirical interventions based solely on palpation anatomical landmarks to high-precision image-guided procedures. However, the complexity of accurately identifying the pain generator remains a crucial bottleneck. The frequent lack of direct correlation between radiological imaging findings and patient symptoms can induce therapeutic failures or inappropriate management. Added to this, the transition between mechanical nociceptive pain and central sensitization requires refined diagnosis from the specialist. Mastering topographical anatomy, judicious target selection, and rigorous technical execution under fluoroscopy are essential to maximize analgesic efficacy and mitigate potentially severe complications, such as neurological deficits or vascular accidents in percutaneous procedures.
• Chapter Objective: This chapter enables the reader to understand the historical evolution and current role of interventional procedures in spinal pain management. By the end of the reading, the professional will be able to recognize the anatomy and innervation of pain-generating structures, correlate the clinical presentation with radiological findings, and properly select indications and contraindications for spinal blocks and infiltrations. Additionally, the reader will master the technical steps of facet and epidural approaches, preventing and managing complications.
• Overview and FundamentalsTopographical Anatomy and Pain Generators Precise identification of nociceptive origin is based on Bogduk's criteria. Facet joints are synovial structures innervated by the medial branches emerging from the nerve root of the corresponding level and the level above. In the lumbar spine, the medial branch crosses the junction between the transverse process and the superior articular process, sending branches to the joints, multifidus muscle, and periosteum. In the thoracic and cervical transitions, anatomical landmarks vary: in the subaxial cervical segment, branches cross the center of the articular pillar, whereas in the thoracic spine they lie over the transverse processes. In turn, the epidural space accommodates nerve roots and the dural sac. The intervertebral foramen is bounded by pedicles, facet joint, and intervertebral disc, being a frequent site of radicular compression. Clinical Framework and Diagnostic Methods Pain conditions are divided into non-specific low back pain (absence of clear anatomical-pathological alteration), radicular pain or stenosis, and specific causes (such as infections or fractures). Magnetic resonance imaging remains the modality of choice to evaluate soft tissue and nerve root compromise. Diagnostic medial branch blocks with local anesthetic confirm facet-origin pain, guiding the indication for therapeutic or decompressive procedures. Operative Techniques and Interventional Approaches Procedures must be performed under real-time fluoroscopy for three-dimensional needle control. Conscious sedation should be maintained at a superficial level in perineural approaches to allow the patient to communicate any neuritic pain: Facet Infiltration and Medial Branch Block: In the lumbar spine, oblique fluoroscopic view ("Scotty Dog") directs the needle to the anatomical target at the junction between transverse process and superior articular process. Local anesthetic combined with or without corticosteroids is employed. Transforaminal Epidural Infiltration: The subpedicular route delivers medication directly into the disc-radicular conflict zone. Mandatory use of non-ionic radiopaque contrast under dynamic fluoroscopy ensures perineural spread and excludes accidental intravascular or intrathecal injection. Sacral Hiatus Infiltration: Anatomical access through the bony defect in the S4-S5 lamina, ideal for caudal epidural coverage. Complications and Precautions Severe complications relate to inadvertent intravascular injection of particulate corticosteroids (triamcinolone or methylprednisolone), which can cause embolization and spinal cord infarction. In cervical and transforaminal pathways, preferential use of non-particulate corticosteroids, such as dexamethasone, is recommended. Detection of post-dural puncture headache, infections, and epidural hematomas requires immediate therapeutic action.
• Clinical Application: In daily clinical practice, selecting patients for infiltrations or blocks requires systematic reasoning grounded in medical history, detailed physical examination, and imaging studies. The physician must clearly distinguish pure axial pain—with a strong facet component—from radicular pain caused by disc herniations or foraminal stenosis. Procedural planning includes proper prone positioning, prior verification of normal coagulation status, and judicious use of fluoroscopy. During transforaminal approaches, real-time radiopaque contrast injection under fluoroscopic visualization is an indispensable step to confirm perineural spread and eliminate accidental vascular injection risk. In drug selection, non-particulate corticosteroids (such as dexamethasone) are preferred in pathways at risk for spinal cord infarction. Post-procedure, the patient should be monitored for symptomatic relief and encouraged to initiate early physical rehabilitation to consolidate functional outcomes.
