Subacromial Shoulder Pain is an umbrella term used to describe shoulder pain caused by problems in the subacromial space; the term replaces the old term shoulder impingement.
The subacromial space is the space between the acromion (flat bone at top of shoulder that is connected to the shoulder blade) and the humeral head (the ball of the shoulder). The space contains one of the rotator cuff tendons (the supraspinatus) and the subacromial bursa.
Shoulder impingement is an old term that gave the impression that pain was caused by the rotator cuff tendon and bursa being pinched between the humeral head and acromion and we now realise that this is an oversimplification, and that pain can happen with no mechanical problem.
Pain can be caused by problems with the rotator cuff tendon, the subacromial bursa or both. Rotator cuff tendon problems that can cause subacromial pain include rotator cuff tendinopathy, partial thickness rotator cuff tears, and calcific tendonitis. Subacromial bursitis is the main bursal problem.
WHAT ARE THE SYMPTOMS OF SUBACROMIAL SHOULDER PAIN?
Patients with subacromial shoulder pain mostly complain of pain on the outside of the shoulder over the deltoid muscle. The pain can sometimes radiate down the arm to the elbow. Pain is usually not a problem when resting but patients often describe pain when lifting the arm forward or out to the side above shoulder height. Some patients experience pain laying on the affected shoulder at night.
WHAT IS THE TREATMENT FOR SUBACROMIAL SHOULDER PAIN?
The first line of treatment should be non-operative. Over the counter pain killers and anti-inflammatories can help with pain and inflammation. Most patients with shoulder pain tend to rest their shoulder to avoid pain and this can quickly lead to weakness of the rotator cuff muscles, so it is important to exercise the shoulder to improve strength and posture for long term control of symptoms.
If these self-management options do not work, some patients may go on to need a subacromial steroid injections for control of pain and inflammation, and formal exercise focused physiotherapy to work on strength and posture. Patients usually require at least 12 weeks of physiotherapy to see long term improvements.
Patients with calcific tendonitis may require slightly different treatment. You can read more about this condition here.
In some patients who fail to improve after steroids and physiotherapy and have persistent pain, surgery may be required. Any surgery required depends on the cause of the pain.
Rotator cuff tendinopathy (pain caused by tendon problems when there is no tear) is not helped by surgery at all.
Partial thickness tears that cause persistent pain despite non-operative management may require treatment similar to a full thickness rotator cuff tear.
Patients with persistent subacromial bursitis may require an arthroscopic subacromial decompression. This operation has become less and less necessary with good physiotherapy. If you are struggling to find a good physiotherapist, please get in touch.