Sacroiliac joint injection

Sacroiliac joint injections can be performed using a posterior approach into the sacroiliac (SI) joint under fluoroscopic or CT guidance. It is often performed bilaterally.

Indications

• diagnostic: relief of pain after injection of local anaesthetic
• therapeutic: to relieve pain from degenerative or inflammatory conditions of the SI joints ^3-5

Contraindications

There are no specific absolute contraindications, but relative contraindications include ^3-5:

• systemic infection or cutaneous infection over the injection site
• coagulopathy
• contrast reaction or other medication allergies
• pregnancy

Procedure

Preprocedural evaluation

• history of presenting complaint: type, nature, severity, duration and location of back pain
• relevant medical and surgical history
• review relevant laboratory results
• review prior imaging
• counselling patient about onset, length and likelihood of pain relief
• gaining informed consent

Positioning/room set-up

• the patient is typically in a prone position

Equipment

• sterile dressing pack; sterile gown and gloves
• 10 mL syringe, hypodermic needle and local anaesthetic (e.g. lidocaine) for subcutaneous infiltration
• long spinal needle (typically 22 G), 3 mL syringe, steroid (e.g. betamethasone), long-acting local anaesthetic (e.g. ropivacaine, bupivacaine) for intra-articular injection
• low osmolar contrast

Technique

Fluoroscopic-guided

• target SI joint is localised, with a slight rotation of the fluoroscope (20-30°) to optimally visualise the inferior component of the articular space.
• aiming about 1 cm above the lower end of the articular space.
• sterile preparation and draping.
• advance a 22G spinal needle in the posteroinferior aspect of the SI joint.
• optional intra-articular injection of a small amount of contrast to confirm intra-articular position.
• Injection of 1 mL steroid and 1 mL long-acting local anaesthetic.

CT-guided

• perform a preliminary CT of the SI joints
• the target SI joint is localised, with an aim at about 1 cm above the lower end of the articular space
• sterile preparation and draping
• advance a 22G spinal needle in the posteroinferior aspect of the SI joint
• optional intra-articular injection of a small amount of contrast to confirm intra-articular position
• injection of 1 mL steroid and 1 mL long-acting local anaesthetic

Post-procedure care

• pain score assessed immediately and 15-20 minutes post-procedure
• observe for 20-30 minutes for any immediate complications

Complications

Complications are rare ^3-5:

• infection
• allergic/anaphylactic reaction
• local reaction to steroid injection (usually >48 hours)
• transient numbness/paralysis (should resolve in minutes)
• transient difficulty voiding
• bleeding

Outcomes

• 50-80% of patients have immediate pain relief
• 90% of patients without previous spine surgery have pain relief at 12 hours
• symptomatic relief is of 10 months duration, on average ^4,5