The information - the painful shoulder
Consultant shoulder and elbow surgeon Mr Duncan Tennent continues our series of evidence-based lowdowns on common presentations using PUNs and DENs
The patient's unmet needs (PUNs)
A 65-year-old man attends complaining of a painful shoulder. The pain has been going on for about three months and wakes him when he lies on that side at night. There is no history of trauma. Examination reveals restricted movement – especially abduction and internal rotation – but no shoulder muscle wasting. He is otherwise well. He gets a little relief from oral NSAIDs, but is not keen on continuing to ‘pop pills' – he wants a precise label for his problem and some definitive treatment.
The doctor's educational needs (DENs)
There seem to be many different names for painful shoulders – such as rotator cuff syndrome, supraspinatus tendonitis, subacromial bursitis, impingement syndrome and painful arc. Are these all essentially describing the same pathology? Is it necessary in primary care to make a precise distinction, or are the treatments the same?
There does seem to be a plethora of terms – some are more descriptive of the general condition and others more specific about particular pathologies. All of your examples relate to pain derived from the rotator cuff – specifically the supraspinatus – classically presenting with pain over the lateral aspect of the arm made worse by abduction and internal rotation.
The terms are often used interchangeably. The term ‘rotator cuff syndrome' tends to be applied when symptoms are present but no firm diagnosis has been made. ‘Painful arc' is typically used to describe the range of motion with pain.
Physiotherapists frequently describe ‘bursitis' or ‘tendonitis', while orthopaedic surgeons tend to use the term ‘subacromial impingement'.
In reality there is no good way of distinguishing between the different diagnoses and the literature is somewhat confused as to exactly what each one means.
Fortunately, in the early stages it is not necessary to make a firm diagnosis – the treatment for all the conditions is the same. If the shoulder is very irritable, rest, ice and NSAIDs will often settle it.
If the symptoms are mild or respond to simple treatments, physiotherapy may be beneficial.
But it is important to note that none of these descriptions cover a rotator cuff tear – usually called ‘frozen shoulder' or ‘capsulitis' – which requires imaging to diagnose. In this case, after the acute phase there is a loss of both active and passive external rotation which is nearly always preserved with rotator cuff pathology.
Patients presenting with a painful shoulder often seem to have the pain for a long time – what is the prognosis in most cases?
Most rotator cuff pain either settles spontaneously within a few weeks or with simple remedies – NSAIDs and rest, physiotherapy or steroid injections. But most patients will have tolerated the pain for some time before they seek help. The rotator cuff weakens with relative disuse and patients adopt compensatory mechanisms, resulting in muscular imbalances.
What is the evidence for benefit of local steroid injections and physiotherapy?
Both have proven benefit. In rotator cuff pain the subacromial bursa often becomes very inflamed, stopping the patient using the shoulder properly. A steroid injection will often reduce this, improving movement and helping the patient to do physiotherapy. There is no evidence as to which steroid should be administered and there is no evidence that a particular approach (posterior or lateral) has any advantage. There is some evidence that ultrasound-guided injections are better, but this is relatively weak. Go to pulsetoday.co.uk/ videos to watch videos demonstrating joint injection techniques – including injecting into the subacromial space.
There is good evidence that physiotherapy helps patients strengthen and regain control of the rotator cuff muscles and it often improves posture.1 Despite this, up to 50% of patients with a diagnosis of impingement syndrome will request surgery.2
Who should be referred for surgery? Do investigations in primary care – such as X-ray or MRI – help the GP to decide?
Often patients need to be referred for an opinion rather than for surgery directly. Referral depends on the GP's skill set – if you are able to inject and are comfortable with the diagnosis of rotator cuff pain, this is a very reasonable first step.
Imaging is not usually required in the early stages of diagnosis and treatment of rotator cuff pathology,3 because, as mentioned earlier, the treatments are the same regardless of the provisional diagnosis. But if onward referral is required it is certainly helpful to have imaging as this can shorten the diagnostic and treatment pathway.
An X-ray is nearly always normal in rotator cuff disease and is probably not worth doing, unless there is a history of trauma or possible calcific tendinitis. Ultrasound is simple to undertake and has a very high sensitivity and specificity for rotator cuff pathology. If the patient is not responding to initial management, ultrasound can be useful – it is certainly very good at diagnosing full-thickness tears but not helpful in partial thickness tears. MRI is more accurate for partial tears, but no better than ultrasound for diagnosing full tears – and is more expensive. An MRI may be more useful if the problem is felt to be deeper, but this decision can usually be made after referral.
We need to be careful about imaging the shoulder too early as there is a high incidence of asymptomatic cuff tear in the normal population. Patients often feel that a tear must be repaired, even though there is no evidence for this, and it can be difficult to dissuade them.
Occasionally, patients suffer bilateral rotator cuff syndrome. How can this be distinguished from important differentials, such as polymyalgia rheumatica?
Symptoms in both shoulders are fairly common. Usually one follows the other as a result of overuse of the normal shoulder to compensate. The important differentials are cervical root irritation and polymyalgia rheumatica. Cervical root irritation can be reproduced by moving the neck and stretching the arm, and usually does not present with the ‘painful arc' pattern seen with cuff pathology.
Polymyalgia rheumatica is usually more diffuse and, again, the classical arc is not present. Provocative testing of the rotator cuff does not produce pain in this condition, but often will with cuff-derived pain.
- Trauma suggests the possibility of rotator cuff tear or dislocation. Acute, very severe atraumatic pain is highly likely to be calcific tendinitis.
- Rotator cuff pain is usually felt in the lateral upper arm. Deeper ‘joint pain' or generalised pain may be arthritis or early adhesive capsulitis. Tenderness localised to the acromioclavicular joint is usually very specific and easily identified.
- On physical examination there is usually no tenderness or obvious muscle wasting.
- Unless the pain is very severe, most patients have normal external rotation. If this is lost then the diagnosis will be arthritis or adhesive capsulitis
- Abduction will usually produce a ‘painful arc' with lateral pain but the arc is not always at the horizontal. Often there is also a painful arc in flexion, and internal rotation (hand behind the back) is limited and painful.4
- For most cases of pain related to cuff pathology a bursal injection of steroid can be beneficial.
- If there is some improvement then referral to physiotherapy may be appropriate. If the result is poor and the patient is still too sore to be able to do physiotherapy then onward referral is indicated.
- If the diagnosis is calcific tendonitis then prompt X-ray and a bursal steroid injection can greatly improve symptoms.
- If the pain is not severe then physiotherapy may improve posture and strengthen the rotator cuff.
Mr Duncan Tennent is a consultant shoulder and elbow surgeon at The London Clinic, and consultant orthopaedic surgeon and honorary senior lecturer at St George's Hospital, London
For more information, visit www.thelondonclinic.co.uk
1 Kuhn JE. Exercise in the treatment of rotator cuff impingement: a systematic review and a synthesized evidence-based rehabilitation protocol. J Shoulder Elbow Surg 2009;18(1):138-60
2 Lewis J and Tennent TD. How effective are diagnostic tests for the assessment of rotator cuff disease of the shoulder? in Evidence-based Sports Medicine. Eds MacAuley D and Best TM Blackwell BMJ Books, London April 2007
3 Tennent TD, Beach WR and Meyers JF. A review of the special tests associated with shoulder examination. Part 1: The Rotator Cuff Tests. American Journal of Sports Medicine 2003;31(1) 154-160