Subacromial Injection

Indications: Diagnostic and therapeutic purposes of –

1. Shoulder impingement
2. Supraspinatus tendinitis
3. Subacromial bursitis

Syringe preparation:

1. Size: 5-10 ml
2. Needle: 21 G
3. Steroid: 0.5-1 ml Methylprednisolone (Depomedrol) 40 mg/ml
4. Local anesthesia: 5-10 ml Lignocaine 1% or Bupivacaine 0.5%

Position:

Comfortably seated with the arm at the side and the hands resting on the lap.

Posterior approach:

1. Identify posterolateral corner of the acromion.
2. The needle should be inserted just inferior and lateral to the posterolateral corner of the acromion aiming slightly up and medial, toward the acromioclavicular joint.
3. The needle should be felt to pass just beneath the acromion, and when placed within the bursa, it should be possible to gently sweep medial and lateral with little resistance.
4. Aspirate prior to injection
5. Fluid should flow freely into the bursal space when injecting, if not the needle is withdraw slightly to remove its tip from soft tissue while injecting.

Lateral approach:

1. Identify and mark inferolateral margin of acronion.
2. The needle should be inserted 1-1.5 inches below the middle of the acromion aiming slightly upwards. If the humeral head is contacted, withdraw and reinsert in a more superior direction.
3. Direct the needle perpendicularly until the bone is reached and withdraw the needle 1-2 mm. At approximately 1 inch deep, needle should be in the subacromial bursa. To aim around supraspinatus tendon, position the needle over the anterior edge of the acromion.
4. As in posterior approach, confirm the position of needle by aspirating and feeling of no resistance while injecting.