Piriformis Steroid Injection

KEY FACTS

Terminology

• Selective image-guided injection of long-acting anesthetic and corticosteroid into piriformis muscle adjacent to sciatic nerve in treatment of piriformis syndrome

  • Some advocate intramuscular botulinum toxin A injection

Preprocedure

• Injection is generally reserved for cases in which conservative measures/physical therapy have failed

• Preprocedure imaging

  • Look for signs of lumbosacral plexus compression

  • Evaluate sacroiliac joints

  • Rule out hip joint abnormality

  • Evaluate for pelvic musculature abnormality/asymmetry

• Nerve stimulator may further assist in confirming needle tip placement prior to injection

Procedure

• Optimize patient positioning depending on imaging technique to be used

  • Can be guided by fluoroscopy, CT, or ultrasound

• Advance needle with intermittent imaging guidance until within fascial plane/muscle sheath at superficial margin of piriformis muscle

  • Intramuscular placement for botulinum toxin A injection

• Note patient's pain before, during, and after injection

• Complications:

  • Sciatic nerve injury

  • Bleeding, infection

Post Procedure

• Maximal benefit may take 48-72 hours when corticosteroid takes full effect

TERMINOLOGY