Sacroiliac joint injection

Indications for the procedure

The primary clinical indication for the injection is axial mechanical lower back pain that characteristically radiates to the buttocks. This procedure is particularly in demand among patients with a specific medical history and concomitant degenerative changes of the musculoskeletal system.

Typical conditions for which the blockade is indicated include:

• Post-surgical status after lumbar spinal fusion.
• Presence of spondylosis at the L5–S1 segment level.
• Bilateral degenerative osteoarthritis of the sacroiliac joint (SIJ).

In these cases, the injection not only relieves the pain syndrome but also confirms the source of pain.

Technique and X-ray anatomy

The procedure is performed under mandatory fluoroscopic guidance. The patient is placed in the prone position (prone). Achieving perfect visualization of the joint space is crucial.

Visualization and access features: The contralateral oblique projection with a slight cranial angulation of the X-ray tube is considered optimal, as it aligns the contours and clearly visualizes the joint space. The needle is inserted strictly into the caudal part of the joint capsule.

The shape of the joint on the radiograph varies depending on the viewing angle:

1. In the ipsilateral oblique projection, the joint is visualized in an ear-shaped configuration (ear-shaped configuration).
2. In the lateral projection, it takes on an oblong configuration (oblong configuration).

Administration of medications: A contrast agent is mandatory prior to injecting the therapeutic solution. It is necessary for precise outlining of the joint space and confirmation of the intra-articular position of the needle. Only then is the therapeutic mixture administered, consisting of 1 ml of 2% lidocaine (lidocaine) and 1 ml of betamethasone (betamethasone) at a dosage of 6 mg.

Specifics of cervical facet syndrome

Unlike the lumbar region, where sciatica symptoms typically dominate, facet pain (cervical facetogenic pain) comes to the forefront in the cervical spine. More than 50% of patients complaining of neck pain have precisely this diagnosis.

Clinical presentation: Patients complain of unilateral pain that does not radiate to the arm (without radiation to the arm). Symptoms are accompanied by marked tenderness and restricted range of motion, especially during rotation and extension (retroflexion / retroflexion) of the neck.

Management strategy: Traditionally, treatment begins with conservative measures: physical therapy, manual therapy (manipulation), and mobilization techniques. However, it is important to note that the evidence base for the efficacy of these methods is rather weak (supported by little evidence). If they fail, interventional techniques are employed (in some cases, cervical dorsal root ganglion — cervical DRG — ablation is also used to enhance pain relief).

Complications of spinal injections (cervical level)

Although complications from spinal blockades are rare, at the cervical level they can have catastrophic consequences. Extreme attention to anatomical landmarks is required.

Globally, there are two dangerous groups of complications associated with inadvertent intravascular administration of drugs:

• Spinal cord injuries: Develop as part of anterior spinal artery syndrome (anterior spinal artery syndrome). The pathogenesis is associated with the accidental injection of a particulate steroid suspension (particulate steroid) into a radiculomedullary branch (radiculomedullary branch) supplying blood to the anterior spinal artery.
• CNS side effects: Include involvement of the brainstem and cerebellum. They occur if the anesthetic and steroid drugs are erroneously injected directly into the vertebral artery (vertebral artery).

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Radiological patterns of the sacroiliac joint (ear-shaped and oblong configurations).
• Pathophysiology of anterior spinal artery syndrome (anterior spinal artery syndrome).
• The role of radiculomedullary branches in the blood supply to the cervical spinal cord.
• Rationale for the composition of the therapeutic mixture (lidocaine and betamethasone).
• Cervical dorsal root ganglion (cervical DRG) ablation as a method for pain management.

Other topics in the "Interventional radiology" section

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