Acromioclavicular joint injection (technique)

Radiopaedia • CC-by-nc-sa 3.0 • de

Acromioclavicular joint (ACJ) injections under image guidance ensure precise delivery of an injectate into the joint.  Ultrasound allows for real time visualization of the needle and administration of the injectate. Fluoroscopy is an alternative method of image guidance.

Indications

Contra-indications

Absolute
  • anaphylaxis to contrast/ injectates
  • active local/ systemic infection 
Relative
  • bleeding diathesis
  • recent injection with steroid in same/other body parts
  • unable to remain still for the procedure
  • young age

Procedure

The general principles of ACJ injections are to

  • cannulate the joint
  • confirm an intra-articular position with imaging
  • administer intra-articular injectate, usually a corticosteroid and a small amount of longer-acting local anesthetic. The ACJ is a small joint therefore the injected volume should reflect this i.e maximum 2mL.
Pre-procedural evaluation

Relevant imaging should be reviewed, and details of the patient confirmed.  The patient should have an opportunity to discuss the risks and benefits and consent obtained.

Risks include

  • infection
  • bleeding
  • allergy 
  • focal fat necrosis/ skin discolouration at the injection site
  • steroid flare
Equipment
  • ultrasound machine, sterile probe cover and a skin marker (ultrasound)
  • skin marker, a metal rod for marking and short connecting tube (fluoroscopy)
  • skin cleaning product
  • sterile drape
  • sterile field and tray for sharps
  • syringe selection i.e. 5mL and 3mL (US)
  • larger bore drawing up needle
  • needle to administer local anesthetic i.e. 30 or 25-gauge needle
  • needle to cannulate the joint i.e. 25 or 27-gauge needle
  • injectants i.e. local anesthetics, iodinated contrast, corticosteroid preparation
  • sterile gauze
  • adhesive dressing
Syringe selection

Using a Luer lock syringe to inject the smaller ACJ will mean no disconnection of the needle and syringe during the injection, as the joint is often under pressure.

A suggested syringe and injectate selection for an ultrasound-guided ACJ anesthetic arthrogram injection

  • 5 mL syringe: 3 mL of local anesthetic i.e. 1% lidocaine
  • 3 mL syringe (Luer lock): 40mg triamcinolone acetonide (40 mg/1 mL) and 1 mL 0.5% ropivacaine

A suggested syringe and injectate selection for a fluoroscopic-guided ACJ anesthetic arthrogram injection

  • 10mL mL syringe: 3 mL of local anesthetic i.e. 1% lidocaine
  • 5 mL syringe (Luer lock): 3 mL non-ionic iodinated contrast i.e. iohexol 300
  • 3 mL syringe (Luer lock): 40mg triamcinolone acetonide (40 mg/1 mL) and 1 mL 0.5% ropivacaine
Needle selection

Smaller gauge needles can be less painful but are less stiff and can bend when trying to cannulate a joint.

  • ACJ: 25 or 27-gauge needles

Technique

Ultrasound in-plane
  • check for allergies and if on blood thinners
  • consent
  • optimize patient positioning by lying them flat and supine on the bed for cranial access, or at 45 degrees for anterior access
  • identify ACJ in the transverse plane; perpendicular to the clavicle, and optimize imaging and mark skin entry point
  • clean skin and draw up appropriate medications
  • consider local anesthesia along the proposed needle path
  • under ultrasound guidance using anterior or cranial access, insert the needle in-plane with the probe into the ACJ
  • administer arthrogram injectate under direct visualization
  • remove needle and apply dressing/ band-aid as required
Ultrasound out-of-plane
  • check for allergies and if on blood thinners
  • consent
  • optimize patient positioning by lying them flat and supine on the bed or at 45 degrees, the joint will be accessed cranially
  • identify the ACJ in a longitudinal plane; parallel to the clavicle, with the ACJ in the center of the image. Optimize imaging and mark skin at the probe midpoint
  • clean skin and draw up appropriate medications
  • consider local anesthesia along the proposed needle path
  • under ultrasound guidance using cranial access, insert the needle at the probe midpoint and out-of-plane with the probe into the ACJ
  • administer arthrogram injectate
  • remove needle and apply dressing/ band-aid as required
Fluoroscopy
  • check for allergies and if on blood thinners
  • consent
  • optimize patient positioning by lying them supine on bed, the joint is accessed anteriorly
  • optimize imaging field and using the metal rod, mark the skin at the target entry at the midpoint of the joint
  • clean skin and draw up appropriate medications
  • consider local anesthesia along the proposed needle path
  • under fluoroscopic guidance using anterior access, insert a needle into the ACJ
  • check for an intra-articular needle tip position with a small amount of iodinated contrast via connection tubing and save a post injection image
  • administer arthrogram injectate
  • remove needle and apply dressing/ band-aid as required

Complications

Steroid flare is a relatively common side effect which will settle after 1 or 2 days.  The most serious complication is infection causing septic arthritis. Steroid containing injections should be postponed if there are any signs and/or symptoms of local and/ or systemic infective.  Fat necrosis causing skin dimpling and skin discolouration can occur due to steroid leaking into the surrounding soft tissues .

Siehe auch: