Sternoclavicular joint injection (technique)

Sternoclavicular joint (SCJ) injections under image guidance ensure precise delivery of an injectate into the joint and importantly that needle depth is under direct visualisation.  

Indications

• pain - arthropathy i.e.
• arthropathy, e.g. osteoarthritis
• diagnostic injection

Contra-indications

Absolute

• anaphylaxis to contrast/ injectates/injectates
• active local/ systemic/systemic infection 

Relative

• bleeding diathesis
• recent injection withmusculoskeletal steroid in same/ other body partsinjection
• unable to remain still for the procedure
• young age

Procedure

The general principles of SCJ 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 anaesthetic, i.ee.g. ropivacaine. The ropivacaine; he SCJ is a small joint, therefore, the injectate volume should reflect this.

Pre-procedural evaluation

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

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
• skin cleaning product
• sterile drape
• sterile field and tray for sharps
• syringe selection i.e. 5mL5 mL and 3mL3 mL
• larger bore drawing up needle
• needle to administer local anaesthetic i.e. 30 or 25-gauge needle
• needle to cannulate the joint i.e. 25 or 27-gauge needle
• sterile gauze
• adhesive dressing

Syringe selection

Using a Luer lock syringe for the injectate will mean the needle and syringe will not disconnect, as the joint is often under pressure.  

A suggested syringe and injectate selection for an ultrasound-guided SCJ anaesthetic arthrogram injection –:

• 5 mL syringe: 3 mL of local anaesthetic i.e, e.g. 1 1% lidocaine
• 3 mL syringe (Luer lock): 40mg, e.g. 40 mg 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.

• SCJ: 25 or 27-gauge needles

Technique

Ultrasound

• check for allergies and if on blood thinners
• consent
• optimise patient positioning by laying them supine on the bed at 45 degrees for anterior access
• identify the joint in a transverse plane; perpendicular to the clavicle, optimise imaging and mark skin entry point
• clean skin and draw up appropriate medications
• consider local anaesthesia along the proposed needle path
• under careful ultrasound guidance using anterior access, insert the needle in-plane with the probe into the SCJ, taking extreme care not to insert the needle too deep by keeping the tip in constant view 
• administer arthrogram injectate under direct visualisation
• remove the needle and apply dressing/ band-aid as required

Complications

Steroid flare is a relatively common side effect which will settle after 1 -2 days.  The most serious complication is an infection causingseptic arthritis. Steroid containing injections should be postponed if there are signs and/or symptoms of local and/ or systemic infection.  Possible fat necrosis causing skin dimpling and skin discolouration can occur due to steroid leaking into the surrounding soft tissues, and this should be included in the consent, for this procedure especially in this visible area ¹.