Ultrasound-Guided Suprascapular Nerve Block (SSNB)
The suprascapular nerve (C5–C6) supplies the posterior and superior shoulder capsule. It arises from the upper trunk of the brachial plexus, with a variable C4 contribution, passes laterally through the posterior triangle of the neck, enters the supraspinous fossa through the suprascapular notch beneath the transverse scapular ligament, and then runs in the floor of the fossa deep to the supraspinatus muscle accompanied by the suprascapular artery and vein. Distal to the notch it gives articular branches to the posterior and superior joint capsule and the acromioclavicular joint, and motor branches to supraspinatus and infraspinatus. The posterior ultrasound-guided approach deposits local anaesthetic in the fascial plane on the bony floor of the supraspinous fossa, proximal to the notch, where the nerve and vessels are reliably found. Crucially, the suprascapular nerve is not the only nerve supplying the shoulder: the axillary nerve supplies the inferior and anterior capsule and the skin over the deltoid, and the lateral pectoral, subscapular and musculocutaneous nerves contribute variably to the anterior capsule and surrounding soft tissue.
Indications
- Acute severe shoulder pain requiring analgesia in the emergency department — rotator cuff pathology, calcific tendinopathy, acute-on-chronic glenohumeral pain
- Analgesia for proximal humerus and shoulder girdle injury as part of a multimodal strategy
- Adjunct analgesia when reducing an anterior shoulder dislocation, to reduce (not replace) sedation and opioid requirement
- Patients in whom opioids are poorly tolerated or contraindicated
- Patients at high risk from procedural sedation (frailty, significant comorbidity, recent food intake) where a block may reduce sedation requirement — discuss with a senior clinician and anaesthetics
- Facilitating positioning for imaging, sling application, dressing changes and early physiotherapy
- Reducing opioid requirement while awaiting definitive orthopaedic management
Contraindications
- Patient refusal, or inability to consent or cooperate
- Infection or cellulitis over the injection site
- Known allergy to local anaesthetic agents
- Significant coagulopathy or therapeutic anticoagulation — the suprascapular vessels are not compressible, so assess risk versus benefit and seek senior advice
- Distorted anatomy, previous scapular surgery or body habitus preventing confident sonographic identification of the fossa floor and nerve
- Pre-existing suprascapular neuropathy or unexplained shoulder weakness (relative — examine and document the deficit before blocking)
- Severe respiratory compromise or single functioning lung, where a pneumothorax would be poorly tolerated (relative)
- Operator not trained and assessed in the technique, or absence of monitoring, resuscitation equipment and 20% lipid emulsion
- Suspected neurovascular injury of the limb requiring serial neurological assessment (relative — document findings first and discuss with orthopaedics)
Technique
- Confirm indication, obtain consent, and complete the Stop Before You Block pause for site and side. Document a pre-block neurovascular examination (axillary nerve sensation over the deltoid, distal pulses, motor function)
- Establish IV access and monitoring. Resuscitation equipment and 20% lipid emulsion must be immediately available
- Calculate the maximum safe local anaesthetic dose for this patient, including any local anaesthetic already given
- Position the patient sitting and leaning slightly forward, or lateral decubitus with the affected side uppermost. Adducting the arm across the chest rotates the scapula laterally and opens the supraspinous fossa. Position the screen in your direct line of sight
- Full aseptic technique: skin antisepsis, sterile probe cover and gel, sterile gloves
- Use a high-frequency linear probe (10–15 MHz); a curvilinear probe may be needed in larger patients. Set depth to about 3–5 cm and optimise gain on the bony floor
- Place the probe in a coronal oblique plane over the scapular spine, then slide and tilt cranially into the supraspinous fossa. Identify trapezius, supraspinatus beneath it, and the continuous hyperechoic floor of the fossa
- Track laterally along the floor towards the suprascapular notch to find the nerve and accompanying vessels on the fossa floor
- Apply colour Doppler to identify the suprascapular artery and vein and any other vessels in the needle path. Plan a trajectory that avoids them
- Infiltrate the skin, then insert a 50–80 mm short-bevel block needle in-plane, medial to lateral, aiming for the fascial plane on the bony floor beside the nerve — not into the nerve
- Maintain continuous needle-tip visualisation at all times. If the tip is not clearly seen, stop advancing, adjust the probe or withdraw and realign. Never advance a needle you cannot see
- Keep the hyperechoic bony floor in view as a backstop. Do not direct the needle medially past the medial edge of the fossa or allow it to pass off the bone, where the pleura lies only a short distance deep
- On gentle bone contact, withdraw 1–2 mm. Aspirate, then hydrodissect with 1–2 mL to confirm the needle tip is in the correct plane and spreading along the fossa floor
- Inject 5–10 mL incrementally in 3–5 mL aliquots, aspirating between each aliquot and watching the spread on screen
- Stop injecting immediately if there is pain on injection, high injection resistance, paraesthesia, no visible spread, or any suggestion of intraneural or intravascular placement
- Remove the needle, apply a dressing, and monitor the patient for at least 30 minutes for signs of local anaesthetic systemic toxicity
- Reassess pain score and range of movement at 15–20 minutes before deciding whether analgesia is adequate for the intended procedure. Document drug, concentration, volume, total milligram dose, ultrasound findings, complications and post-block neurovascular status
Drug Doses
| Agent | Concentration | Volume | Total Dose | Notes |
|---|---|---|---|---|
| Ropivacaine | 0.5% | 5–10 mL | 25–50 mg | Reasonable first choice — long acting with a favourable cardiac safety profile. Maximum dose 3 mg/kg (maximum 200 mg) as listed on the LA Drugs page. |
| Levobupivacaine | 0.25% | 5–10 mL | 12.5–25 mg | Low-dose option when other local anaesthetic has already been given or cumulative load is a concern. Maximum dose 2 mg/kg (maximum 150 mg). |
| Levobupivacaine | 0.5% | 5–10 mL | 25–50 mg | Denser, longer block for significant injury pain. Still well inside the 2 mg/kg (maximum 150 mg) limit at these volumes in an average adult. |
| Bupivacaine | 0.25% | 5–10 mL | 12.5–25 mg | Use only where levobupivacaine or ropivacaine is unavailable — the most cardiotoxic of the amides. Maximum dose 2 mg/kg (maximum 150 mg). Never for intravascular use. |
| Lidocaine (Lignocaine), plain | 1% | 5–10 mL | 50–100 mg | Rapid onset 2–5 minutes, duration only 1–2 hours. Consider when the block is an adjunct to an imminent reduction attempt, accepting that analgesia will wear off early. Maximum dose 3 mg/kg plain, 7 mg/kg with adrenaline 1:200,000. |
Complications
Landmarks
- Scapular spine — the first structure to find; a bright hyperechoic line with dense acoustic shadow
- Supraspinous fossa — the hyperechoic bony floor cranial to the scapular spine, which acts as the deep backstop for the needle
- Trapezius (superficial) and supraspinatus (deep) muscles, separated by their fascial planes
- Suprascapular notch and transverse scapular ligament at the lateral end of the fossa
- Suprascapular nerve — small hypoechoic oval structure on the floor of the fossa, deep to supraspinatus
- Suprascapular artery and vein adjacent to the nerve — confirm with colour Doppler before every needle pass
- Acromion, coracoid and clavicle for surface orientation before scanning
Sensory Coverage
Partial shoulder coverage only — posterior and superior glenohumeral joint capsule and AC joint. The suprascapular nerve supplies articular branches to the posterior and superior capsule and the acromioclavicular joint, plus motor supply to supraspinatus and infraspinatus. It does NOT cover the anterior and inferior joint capsule, the skin over the shoulder and deltoid (axillary nerve), the anterior soft tissues supplied by the lateral pectoral and subscapular nerves, or the clavicle and cape of the shoulder (supraclavicular nerves, C3–C4). Analgesia is therefore partial — expect reduced pain and improved tolerance of movement rather than a surgically anaesthetised shoulder. Motor block of supraspinatus and infraspinatus causes temporary weakness of abduction and external rotation.
Clinical Pearls
Background & Evidence
The suprascapular nerve has long been targeted for shoulder analgesia in chronic pain, rheumatology and anaesthetic practice, and the ultrasound-guided posterior approach in the supraspinous fossa has since been adopted for acute shoulder pain. It is attractive in the emergency department because it needs only a small volume of local anaesthetic, can be performed with the patient sitting, and keeps the needle well away from the brachial plexus and phrenic nerve — unlike an interscalene block, which commonly causes temporary hemidiaphragmatic paresis and is rarely appropriate in the ED. Its limitation is anatomical rather than technical: because the axillary, lateral pectoral, subscapular and supraclavicular nerves also supply the shoulder, a suprascapular block reduces pain rather than abolishing it, and it should not be described to patients or colleagues as a reliable substitute for procedural sedation when reducing a dislocated shoulder. Published emergency department experience with the block as an analgesic adjunct is limited compared with the established truncal and lower limb blocks on this site, so local practice varies. Agree indications, training, governance and documentation with your emergency department and anaesthetic leads before adopting it, audit your outcomes and failure rate, and confirm all doses against the current BNF and your local regional anaesthesia policy.
Ultrasound Images
