Sacroiliac Joint Injection

Other Names

• Sacroiliac Joint Injection
• Diagnostic Sacroiliac Joint Injection
• SIJ Injection
• SI Joint Injection

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Background

Illustration of the sacroiliac joint

Illustration of joint injection with needle and probe visualized

Key Points

• Needle: 21-23 gauge, 3.5 inch (spinal)
• Transducer: high frequency, curvilinear
• Most easily accessed at the caudal pole
• Total volume injection: ~2 mL

Anatomy of the Sacroiliac Joint

• Articulation of Sacrum and Ilium
• Diarthrodial Joint with fibrous capsule and synovial fluid
• Function: support the upper body, dampen the impact of ambulation, transfer weight from lower extremities to axial skeleton

Palpation Guidance vs Ultrasound Guidance

• Success rate of unguided injections is 12% when using fluoroscopy as a control
• Ultrasound guided injections have an accuracy of 76% to 93%
• Outcomes of fluoroscopic-guided vs ultrasound-guided have not been described

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Indications

• Sacroiliac Joint Pain

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Contraindications

• Absolute
  • Anaphylaxis to injectates
  • Overlying cellulitis, skin lesion or systemic infection
• Relative
  • Can be treated with less invasive means
  • Hyperglycemia or poorly controlled diabetes
  • Lack of symptom improvement with previous injection

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Procedure

Needle and probe position for short axis, in-plane approach

Ultrasound visualization of the SI joint with the needle in plane (white arrows)

Equipment

• Sterile including chloraprep, chlorhexidine, iodine
• Gloves
• Needle: typically 21-23 gauge, 3.5 inch
• Syringe: 5-10 mL
• Gauze
• Ethyl Chloride
• Bandage
• Injectate
  • Local anesthetic
  • Corticosteroid
• Sterile probe cover

Ultrasound Findings

• Best visualized using a curvilinear probe
  • Place initially over the posterior superior iliac crest
  • S1 foramen can be visualized medial to the cleft of the upper portion of the SIJ
  • Keep probe in axial plane, slide distally to lower pole close to S2

Technique: Short Axis, In-Plane

• Patient position
  • Prone
  • Pillow under hip to provide flexion
• Transducer position
  • Probe placed over PSIS
  • Slide distally over the caudal one third of SI joint
• Needle Approach/ Orientation
  • In-plane
  • Medial to lateral
• Target
  • Distal 1/3 of the SI Joint

Technique: Short Axis, Out-of-Plane

• Patient position
  • Prone
  • Pillow under hip to provide flexion
• Transducer position
  • Probe placed over PSIS
  • Slide distally over the caudal one third of SI joint
• Needle Approach/ Orientation
  • Out-of-plane
  • Caudal to cephalad
• Target
  • Distal 1/3 of the SI Joint
• Pearls and Pitfalls
  • Use color doppler on superficial structures
  • Unable to visualize vasculature once the needle tip is in joint capsule

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Aftercare

• No significant restrictions
• Can augment with ice, NSAIDS

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Complications

• Skin: Subcutaneous fat atrophy, skin atrophy, skin depigmentation
• Painful local reaction
• Infection
• Hyperglycemia
• Tendon, nerve or blood vessel injury

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See Also

• Procedures Main
• Ultrasound Main
• Back Pain Main
• Hip Pain Main

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