Subacromial Bursa Injection

Chronic bursitis

Causes and findings

• Overuse or occasionally trauma

• Pain in deltoid area, often having been mildly symptomatic for a long time. Occasional referral of pain down arm

• Painful: passive elevation and medial rotation more than lateral rotation resisted abduction and lateral rotation, often on release of resistance. These

two muscle groups often appear weak, but this is caused by muscle inhibition often - but not always - arc on active abduction generally - a 'muddle' of signs, with resisted tests repeated under distraction being less painful

Equipment:

Syringe - 5ml

Needle - 21G 1.5 inches (40mm) green

Kenalog 40 - 20 mg

Lidocaine - 4.5 ml 1%

Total volume - 5 ml

Anatomy:

The bursa lies mainly under the acromion but is very variable in size and can extend distally to the insertion of deltoid. Occasionally, a tender area can be

palpated around the edge of the acromion. Sometimes the bursa communicates with the glenohumeral joint capsule.

Technique:

• Patient sits with arm hanging by side to distract humerus from acromion

• Identify lateral edge of acromion

• Insert needle at mid-point of acromion and angle slightly upwards under acromion to full length

• Slowly withdraw needle while simultaneously injecting as a bolus wherever there is no resistance

Aftercare:

The patient must maintain retraction and depression of the shoulders and avoid elevation of the arm above shoulder level for up to 2 weeks. Taping the

shoulder in retraction/depression for a few days, with postural advice, is helpful. When pain free, the patient commences resisted lateral rotation and retraction exercises, followed by strengthening of abduction. Retraining of overarm activities to avoid recurrence is essential.

Comments:

In our experience, this is the most common injectable lesion seen in orthopaedic medicine (see Appendix 1). Results are usually excellent; relief of pain after one injection is usual but the rehabilitation programme must be maintained. If, rarely, the symptoms persist after two injections, the shoulder should be scanned because a cuff tear might be present. In thin patients, the fluid sometimes causes visible swelling around the edge of the acromion.

Alternative approaches:

There is often loculation in long-standing bursitis. In this case, resistance is felt when injecting the solution, so the needle must be fanned around under the acromion to pepper separate pockets of the bursa - the sensation is that of injecting a sponge. Occasionally, calcification occurs within the bursa and

hard resistance is felt. Infiltration with a large-bore needle and local anaesthetic may help. Failing this, surgical clearance is recommended. If palpable

tenderness is found either anterior or posterior to the acromion, the injection can be given at these sites. Acute subacromial bursitis is much less common and presents with spontaneous, rapidly increasing severe pain over a few days, which may radiate down as far as the wrist. The patient is often unable to move the arm at all and sleep is very disturbed. It should be injected in the same way as above but using a smaller total volume of 2 ml.