Chapter 21: Interlaminar Epidural Steroid Injections: Cervical, Thoracic, Lumbar, and Caudal

INTRODUCTION

Epidural steroid injections have been used for the treatment of radicular pain and spinal pathology for many decades. The epidural space can be accessed posteriorly via the interlaminar space. Although using an AP lateral or contralateral oblique fluoroscopically guided approach can be more precise and can also help visualize the spread of the injectate under live fluoroscopic view, a “blind” injection performed by a skilled practitioner using a “loss of resistance” technique to identify passage into the epidural space via the ligamentum flavum has been utilized successfully for years. The relative simplicity of the blind technique and one’s ability to perform it without the use of costly equipment such as a fluoroscopy unit has provided a much-needed procedure to the masses especially in developing countries. The use of interlaminar approach to the epidural space for injection is one of the most frequently used procedures in the practice of interventional pain management.

INDICATIONS

• Unilateral or bilateral radiculopathy resulting from

  • Acute intervertebral disc herniation causing compression or impingement of spinal nerve

  • Acutely herniated nucleus pulposus with compression or local proinflammatory mediator release and resultant nerve irritation

  • Spinal stenosis (acquired or congenital)

  • Foraminal stenosis

  • Lateral recess stenosis

  • Impingement from degenerative disc disease

  • Compression by cysts on zygapophyseal (facet) joints

• Spondylolisthesis

• Spinal deformity (eg, scoliosis)

• Postlaminectomy syndrome

• Pain from vertebral compression fractures

• Pain from herpes zoster

RELEVANT ANATOMY

• Level of interlaminar injections are initially identified via palpation between spinous processes or via identification of the space between vertebrae on fluoroscopic imaging.

• From superficial to deep (dorsal), an epidural needle passes through the following structures for a midline approach: skin, subcutaneous tissues, supraspinous ligament, interspinous ligament, ligamentum flavum, and the epidural space. If the injection proceeds deeper, it comes in contact with the dura mater and the subarachnoid space.

• From superficial to deep (dorsal), an epidural needle passes through the following structures for a paramedian approach: skin, subcutaneous tissues, ligamentum flavum, and the epidural space.

• The epidural space is bounded by the ligamentum flavum and the lamina posteriorly, the posterior longitudinal ligament anteriorly, and the vertebral pedicles and neural foramina laterally.

• The epidural space contains fat, lymphatics, venous plexi, connective tissue, and the spinal nerve roots.

• The ligamentum flavum can be discontinuous in the cervical and high thoracic regions, making localization of the epidural space via loss of resistance technique potentially more challenging.

CONTRAINDICATIONS

• Absolute

  • Local or systemic infection

  • Acute spinal cord compression (injection at that level)

  • Untreated bleeding disorders that predispose to hemorrhage

  • Uncontrolled or untreated systemic disorders (cardiopulmonary, renal, endocrine) where steroid effects may cause acute or subacute decompensation of the patient’s medical condition

  • Hypersensitivity or allergy to medications used in epidural steroid injection

  • Patient refusal

• Relative

  • Preprocedure evaluation in patients with immunosuppressive diseases should be undertaken to rule out the potential for latent infection.

  • Considerations should be made to ...