The subacromial bursa lies between the upper surface of the rotator cuff and the under surface of the acromion. A bursa is really a potential space between two surfaces that move against each other, normally formed by two smooth surfaces with a thin film of fluid between them. Its job is to let movement happen by providing gliding surfaces.
Bursas can become inflamed, and this is called bursitis. There are bursas around all of the joints, and some are particularly troublesome. The subacromial bursa is one of these, and it accounts for a great deal of shoulder pain.
Symptoms
Inflammation of the bursa can cause aching pain down the lateral aspect of the arm. Most people with bursitis will also have symptoms of impingement, a catching pain as the arm is lifted. Night pain, particularly when lying on the affected side, is common.
Causes
A number of problems can lead to bursitis:
- Minor injuries that precipitate inflammation of the bursa
- Injuries to the rotator cuff, including tears and tendonitis
- Calcium build-up in the rotator cuff; inflammation related to this is called calcific tendonitis
- A tight subacromial space, where the bursa is repeatedly compressed during overhead movement
Treatment
Non-surgical treatment
Bursitis is usually treated with a steroid injection into the bursa. Steroids are true anti-inflammatories and can substantially improve the inflammation within the bursa. Physiotherapy alongside the injection addresses the mechanics that led to the bursa being irritated in the first place, which is what gives the best chance of the improvement lasting.
Many people settle with this combination and need nothing further.
Surgical treatment
If steroid injections are unsuccessful and physiotherapy is unable to help, surgery may be considered. Surgery takes the form of removing the bursa (a bursectomy), usually together with an acromioplasty. An acromioplasty is arthroscopic (keyhole) surgery to remove the under surface of the acromion, creating more space to accommodate the rotator cuff, so the shoulder can lift without the cuff catching.
As with any operation there are risks, including those of the anaesthetic, infection and post-operative stiffness. These are discussed individually in consultation before any decision is made.
Recovery
Recovery following an arthroscopic acromioplasty and bursectomy is usually fairly rapid, and normally occurs within the first six weeks after surgery. There is no requirement to wear a sling afterwards, and physiotherapy exercises normally begin within the first few days following the procedure.
What to do next
If you have aching pain down the outside of your arm that is worse at night and has not settled, see your general practitioner. A referral is needed to claim the Medicare rebate for a specialist consultation.
This page is general information and is not a diagnosis. Individual circumstances vary, and the right treatment for you can only be determined after assessment. Any procedure carries risk; these are discussed in consultation.
