Acquired conditions

The painful shoulder

After back pain, shoulder pain is the second most common musculoskeletal problem seen by primary care physicians. The commonest causes of the painful shoulder in adults are disorders of the rotator cuff, particularly the supraspinatus tendon. Although conditions such as the painful arc syndrome, impingement, rotator cuff tears and cuff tear arthritis are often considered as separate conditions, in reality they

are part of a spectrum of disorders of the supraspinatus tendon. Other causes of shoulder pain include calcific tendonitis, frozen shoulder and degenerative disease.

Disorders of the rotator cuff

In common with some other tendons of the body, the supraspinatus tendon has a relatively poor blood supply, and this can predispose to both degenerative changes and tearing of the tendon. The anterolateral portion of the tendon is initially affected and swelling of this portion may lead to impingement between the greater tuberosity of the humerus and the anterior acromion with its attached coraco-acromial (CA) ligament. This leads to pain, particularly on active abduction or flexion, and initially leads to a painful arc between 60-120degree.

Abnormalities of the bone occur, with hooking of the anterior acromion. These are probably secondary changes, rather than the primary cause of the pain, but surgical treatment is often directed against the acromion and the CA ligament.

History and examination

The patient is usually middle aged, and the initial symptoms may be due to a specific traumatic incident or a period of overuse of the arm, or there may be no precipitating events. The pain is activity related, particularly on overhead activities, such as reaching up to shelves or hair washing. Gardening and household activities often produce symptoms. Some patients complain of significant weakness, and this may indicate the presence of a rotator cuff tear.

On examination, there is often no local tenderness. Active movements may be limited, and usually reproduce the symptoms, which occur between 60-120degree of abduction and flexion (Fig. 22.2). There is usually much less pain on passive movements, and this confirms the mechanical nature of the pain. Weakness of both supraspinatus and infraspinatus may be demonstrated, and suggest the possibility of a tear in the cuff. Specific impingement tests have been described and help to confirm the diagnosis (Figs 22.3 and 22.4). Radiographs may be normal, but usually there are signs of subacromial sclerosis.

Subacromial injection of local anaesthetic and cortisone often leads to improvements in the symptoms and they are used for both diagnostic and therapeutic purposes. If the diagnosis is correct, the symptoms are usually improved. The benefit may only be short lived, but this is a valuable diag­nostic aid. Improvement in symptoms occurs for a few weeks after the injection, but subsequent relapse commonly occurs.

Further investigations

A subacromial injection is the most useful diagnostic test, and this is easily performed in the out-patient clinic. Further investigations such as ultrasound and magnetic resonance imaging (MRI) are used to determine the presence of a tear of the rotator cuff if surgery is contemplated; they have little place in the diagnosis of impingement (Fig. 22.5).

Treatment

It is likely that most patients will settle with conservative treatment. The initial treatment is by cortisone injection, and this is repeated up to three times if there is prolonged relief of symptoms. Specific physiotherapy has a role, particularly in the early stages, but most patients who present to specialist clinics will only have a limited response. Surgery is eventually required in 50 per cent of these patients, and is indicated when symptoms, sufficient to limit activities, have been present for over a year. Decompression of the rotator cuff is carried out, either arthroscopically, or by an open procedure, with removal of the anterior overhang and division of the CA ligament. In addition, repair of a rotator cuff tear may be required. In the absence of a rotator cuff tear, the prognosis is good.

Rotator cuff tears

Patients with rotator cuff tears are usually slightly older than patients with impingement. Tearing of the supraspinatus muscles also starts at the front lateral edge of the tendon, and can progress posteriorly along the tendon, detaching it from the greater tuberosity. The tendon retracts medially leading to a U-shaped tear. The patient is usually unaware of the rotator cuff tearing, and large tears of several years’ duration may be present before the patient seeks medical attention (Fig. 22.6).

Small tears of the supraspinatus

These are very common and may be found in up to 20 per cent of the normal population, in the absence of any specific shoulder symptoms. The tear is usually less than 1 cm in length and, in the absence of significant pain, is not of a sufficient size to cause weakness of the shoulder.

Treatment of small tears. Treatment is dependent on the presence and severity of impingement symptoms. In the absence of symptoms, the tear can be left unrepaired, and the patient kept under review. Progression of the tear is an indication for repair. If impingement is a significant problem, decompression is carried out, and the tear can be repaired if appropriate.

Intermediate tears

Tears of 2—3 cm (as measured on ultrasound) are usually associated with symptoms of impingement or weakness of the shoulder, and these will often require decompression and repair of the supraspinatus. This can be carried out through a lateral sabre-type incision. The tendon is mobilised, and then sutured into a bony trough created on the edge of the greater tuberosity, using osseous sutures. Results of repair are good for intermediate tears, but full recovery will take several months. Large tears of the supraspinatus

These are often 5 cm or greater, and may extend into infraspinatus. They are usually associated with weakness of the shoulder, and abduction may be limited to 600, often with a characteristic bunching of the shoulder (Fig. 22.7). With massive tears of the rotator cuff, superior migration of the humeral head can occur, and this further impairs function. In addition, secondary osteoarthritis of the glenohumeral head may occur due to the resulting incongruity of the joint.

Treatment of large tears. If symptoms of impingement or weakness are sufficient, decompression and repair should be considered. Unfortunately repair is not always possible as the medial edge of the tendon retracts, and it may be impossible to mobilise this to close the defect. Tendon grafts and synthetic meshes have been used to close this defect but the results are less than satisfactory. This is due to degeneration and disuse atrophy of the supraspinatus associated with a chronic tear, and although the gap may have been closed there is poor function from the repaired tissue.

In many patients with large tears, the predominant symptom is still pain rather than weakness and in these patients if the tear is irreparable by direct suture, simple decompression is carried out. Up to 80 per cent of these patients will have good relief of symptoms and improved function, despite the unrepaired rotator cuff tear.

Acute tears of the rotator cuff

Most tears of the supraspinatus are due to degeneration and, as discussed above, will be associated with impingement symptoms. Occasionally a large tear of the rotator cuff can result from trauma, in the absence of any previous shoulder symptoms. These patients present soon after the event with profound weakness and loss of function but minimal pain. On examination, there is marked restriction of abduction, usually to less than 900, with a characteristic hunching of the shoulder. This is due to elevation and rotation of the scapula to attempt to aid abduction. Diagnosis is confirmed by ultrasound or MRI, and early exploration and repair is indicated. Unlike the large degenerate cuff tears the acute tear

is usually repairable if surgery is carried out early. Often no decom­pression is necessary, as the front edge of the acromion is normal with no evidence of overhang. In middle-aged and elderly patients an acute cuff tear can occur after shoulder dislocation.

Frozen shoulder

This is a painful shoulder condition of unknown aetiology that affects the capsule of the shoulder. The rotator interval between supraspinatus and subscapularis is affected predomi­nantly. The disease most commonly affects females in their 50s, and is more common in diabetics and patients with heart or thyroid disease.

History and examination

The pain is often of sudden onset and may follow minor trauma. It is severe and often disturbs sleep, and fractures or joint infection may be considered in the differential diag­nosis. In the early stages, the shoulder is difficult to examine owing to the pain, but as the disease progresses the range of motion is reduced, both actively and passively. Local tender­ness is often felt anteriorly over the rotator interval. The pathognomonic sign of frozen shoulder is loss of external rotation and this differentiates it from rotator cuff disease. Plain X-rays exclude other intra-articular pathology.

Clinical course

The clinical course of frozen shoulder can be divided into three stages as follows.

  Stage I — a painful phase — can last for 2—9 months. The shoulder becomes increasingly painful, especially at night, and the patient uses the arm less and less. The pain is often very severe, and may be unrelieved by simple analgesics.

Stage 2 — a stiffening phase — can last for 4—12 months and is associated with a gradual reduction in the range of movement of the shoulder. The pain usually resolves during this period, although there is commonly still an ache, especially at the extremes of the reduced range of movement.

Stage 3 — the thawing phase — lasts for a further 4—12 months and is associated with a gradual improvement in the range of motion.

The clinical course runs over a period of 1—3 years and usually resolves without any long-term sequelae.

Treatment

Often no treatment is required and the condition will usually resolve as described above. The range of motion may be slightly reduced compared with the unaffected side, but the vast majority of patients has no functional problems.

Treatment in the acute stage is pain relief. Corticosteroids may be tried but have variable effects. Active and passive mobilisation can be carried out if comfort allows but aggressive physiotherapy should be discouraged.

Surgery is usually reserved for prolonged stiffness affecting function but can also produce good pain relief in the acute stage. Surgical treatment has a limited place in management. Manipulation under anaesthetic may produce an increased range of motion. Arthroscopic distension of the joint with saline allows inspection of the shoulder before treatment. If these measures fail to produce any benefit, open release of the rotator interval can be carried out through an anterior approach.

Calcific tendonitis

This is a common disorder of unknown aetiology which results in an acutely painful shoulder. Calcium is deposited within the supraspinatus, and it is thought that this may be part of a degenerative process. The differential diagnosis includes frozen shoulder, with both conditions occurring most commonly in middle-aged women.

History and examination

This pain is usually of rapid onset, often with no precipitating cause. In common with impingement, the pain is felt on the anterolateral aspect of the shoulder and is worse with activities, particularly overhead activities. The pain can be very severe and usually disturbs sleep. On examination, the shoulder is tender anterolaterally, and there is often some restriction of active and commonly passive motion. External rotation will be possible and this differentiates the condition from frozen shoulder.

The calcific deposits can be seen on plain radiographs, lying within the supraspinatus tendon, inferior to the acromion and just medial to the tuberosity of the humerus. They can also be seen on ultrasound (Fig. 22.8).

Treatment

Simple analgesia should be tried together with physiotherapy, although specialist referral is commonly indicated. Calcific tendonitis usually responds to subacromial injection of corticosteroid, although a course of several injections may be necessary. The condition is often self-limiting with resolution of the symptoms and resorption of the calcium.

Surgery

Resistant cases of calcific tendonitis are an indication for surgical treat­ment. Open excision of the calcific deposits can be carried out through a sabre incision but arthroscopy of the shoulder with subacromial decompression is an alternative. The cuff can be debrided and, if the deposits are prominent, they can be removed through a smaller incision.

The prognosis for calcific tendonitis is generally good.

Arthritis of the shoulder

Rheumatoid arthritis

The glenohumeral joint is commonly involved in inflammatory arthritis, particularly rheumatoid arthritis (RA), with up to one-third of these patients developing severe problems. Initially the pain is related to synovitis and this responds to medical management, including intra-articular steroid injection.

Impingement symptoms can also occur, either with or without a rotator cuff tear. These will respond to subacro­mial injection but decompression may be indicated. Arthroscopic synovectomy can be carried out at the same time but, in general, open synovectomy is not indicated in the management of RA of the shoulder. Chemical synovectomy may be indicated for symptoms that are resistant to medical treatment but this is not commonly performed for RA.

For advanced disease, glenohumeral arthroplasty is indicated, with very good relief of pain, but there is often little improvement in the preoperative stiffness.

Osteoarthritis

Osteoarthritis of the glenohumeral joint is either primary or more commonly secondary. Secondary arthritis is usually due to previous trauma or to end-stage rotator cuff disease, in association with a massive tear of the cuff and superior migration of the humeral head.

Treatment. As with osteoarthritis of other joints, medical measures are initially tried. Failure of medical management is an indication for surgery. Débridement of the joint and osteotomy have little if any place in the management of glenohumeral osteoarthritis, and joint replacement is the treatment of choice. Both total shoulder replacement and hemiarthroplasty, without glenoid replacement, can be carried out (Fig. 22.9). Total shoulder replacement should only be carried out if the rotator cuff is intact. In most patients with RA, and all patients with cuff tear arthritis, the cuff is deficient and hemiarthroplasty is therefore the most common replacement performed; this can be carried out through an anterior deltopectoral approach. Shoulder

replacement is a very good pain-relieving procedure but, in general, will not restore movement to a stiff shoulder. Arthrodesis of the joint is an alternative in the younger patient, especially if there is a history of sepsis or any neurological problem that would affect the stability of a joint replacement. The perioperative morbidity is higher, however, and 3-4 months of immobilisation are required. The patient retains a surprisingly good range of movement at the shoulder and can function well owing to scapulothoracic movement (Fig. 22.10).

Arthritis of the acromioclavicular (AC) joint

Degenerative changes of the AC joint on plain radiographs are relatively common and are usually age related. Symp­tomatic disease, however, usually affects males in their 20-40s and is commonly due to a previous injury. It is often seen in individuals who play sport or are involved in an occupation that stresses the upper limbs. If inferior osteophytes are present, impingement on the underlying rotator cuff can occur.

History and examination.

The pain is activity related and, unlike most causes of shoulder pain, it is well localised, with the patient pointing to the AC joint as the source of the pain. On examination, there is usually a bony abnormality, with prominence of the distal end of the clavicle. This may be tender and movement of the joint by depressing the clavicle whilst pushing up the humerus will reproduce the pain. Flexing and adducting the arm to place the hand behind the opposite shoulder will also produce pain. An intra-articular injection of local anaesthetic will confirm the joint as the site of the pain. If the symptoms are related to the inferior osteophytes, the pain is less well localised, and impingement signs and symptoms are present.

Treatment. Intra-articular injection of corticosteroids will usually produce some benefit and a course of three injections may be tried. If medical management fails, then surgery may be appropriate. The distal 1/2 to 1 cm of the clavicle is excis­ed by a direct approach, with good relief of pain and no functional difficulties. In patients with predominately impingement symptoms, arthroscopic dehridement of the osteophytes can be carried out.

Rupture of the biceps tendon

Rupture of the long head of biceps is a relatively common condition, occurring in middle age and in the elderly. The condition is closely related to rotator cuff disease and the tendon usually ruptures owing to chronic attrition. Although many patients present acutely, an asymptomatic biceps rupture is a relatively common finding during arthroscopy for rotator cuff surgery.

  History and examination

The patient usually complains of something giving, often when they are lifting. The arm is often bruised and when the patient flexes the elbow a lump is evident in the middle of the biceps. The lump is initially tender and power is diminished (Fig. 22.11).

Treatment

This condition is treated conservatively, and the patient can be reassured that the pain will ease and the power return, although this may take several months.

Rupture of the distal insertion of biceps is an uncommon condition that usually occurs in younger patients, particularly after a sporting injury. Again pain and weakness are present hut, unlike rupture of the long head, the weakness will not improve. Surgical repair is indicated.

Instability of the glenohumeral joint

Traumatic dislocation of the shoulder will be considered in the next section but recurrent instability is a common sequele of dislocation. Recurrent traumatic instability is age related, with over half of shoulder dislocations becoming recurrent in the under 25 year olds. In some patients, the shoulder may dislocate after relatively little force, and a further group of patients with shoulder instability may be able to dislocate the shoulder at will. The diagnosis is based on an accurate history and further investigations, other than plain radiographs, are not usually required.

Classification

There are many ways of classifying shoulder instability, based on direction, the degree of violence required as well as con­sidering subluxations and true dislocations. There is a spectrum of instability but, in general, three groups of patients can be considered as follows (Fig. 22.12).

Recurrent traumatic instability. This is predominately in one direction, most commonly anteroinferiorly. There is a definite traumatic event initially, although less violence is required subsequently. The patient is aware of apprehension on certain activities and sport may be made difficult. The shoulder may sublux or dislocate and often the dislocation has to be reduced in a medical facility. On examination, there is a full painless range of motion but apprehension on forced abduction and external rotation (Fig. 22.13). Other joints are usually normal. As discussed in the section on trauma, there is usually a Bankart defect with detachment of the anteroinferior glenoid labrum and damage to the humeral head (Fig. 22.14).

Treatment. Conservative treatment has little place and, if the instability causes functional difficulties, surgery is indicated. For anterior instability, repair of the Bankart defect, in addition to some tightening of the capsule, will produce good results in 90—95 per cent of patients. This is carried out through an anterior deltopectoral approach (Fig 22.15). For recurrent posterior instability (uncommon) tightening of the posterior capsule through a posterior approach is carried out.

Atraumatic instability. Although there may be an initiating event, this is often less traumatic, for example a fall climbing stairs rather than a sporting injury. In many cases there is no initial injury and the instability may occur in more than one direction. The shoulder usually subluxes rather than dislocates and the patient can often reduce the shoulder themself. The subluxation is painful and the patient will not dislocate the shoulder at will. On examination, generalised ligament laxity is commonly present and the shoulder can often be subluxed inferiorly to produce a sulcus sign, with a lateral sulcus appearing beneath the acromion as the arm is pulled down. Apprehension tests are again positive but often in more than one direction.

 Treatment. Physiotherapy, by an experienced therapist, should be tried first in these patients. As well as muscle strengthening re-education of the patient and shoulder is necessary, and specific muscle groups may need to be targeted.

Approximately half of the patients will require surgery and a capsular tightening procedure is carried out through an anterior approach. This is a successful procedure but there is a higher failure rate than with patients found to have a Bankart defect. Arthroscopic shrinkage of the capsule may have a place in these patients, and this is currently being evaluated.

Habitual dislocation.

 This is a much smaller group of patients, but one which does not respond well to surgical treatment. The patient is able to sublux the shoulder at will and this is usually not painful (Fig. 22.15). There is underlying joint laxity, which is usually generalised, and there is rarely a significant traumatic event. The patient may sublux the shoulder as a ‘party trick’, or for emotional or psychological reasons.

Treatment.

 It is vital that these patients are assessed and managed by an experienced therapist. The patient must be educated to avoid subluxing the shoulder and shown exercises as appropriate. Surgery is associated with a high failure rate and should be avoided.