History

Characteristics of shoulder pain. It is important to find out the precise location and distribution of the pain. True shoulder pain is seldom confined to the shoulder itself. Typically, it radiates from a point near the tip of the acromion down the lateral side of the upper arm to about the level of the deltoid insertion. It is unusual for true shoulder pain to extend below the elbow.

Pain arising in the acromio-clavicular joint or sterno-clavicular joint is localised to the joint itself and does not radiate down the limb.

Referred pain in the shoulder region. The pain referred from an irritative lesion of the brachial plexus often extends from the base of the neck, over the top of the shoulder, and thence into the arm. Unlike true shoulder pain, it frequently radiates below the elbow into the forearm or hand, and it may be accompanied by paraesthesiae – often described as ‘pins and needles’ or ‘a numb feeling’. Pain may also be referred to the shoulder from a lesion in the thorax or upper abdomen.

Exposure

The patient must be stripped to the waist. The examination is conducted most easily with the patient standing; alternatively he may sit upon a high stool. For the greater part of the examination the surgeon stands behind the patient, so that he may observe more easily the position of the scapula.

Steps in routine examination

A suggested plan for the routine examination of the shoulder is summarised in Table 14.1.

Table 14.1 Routine clinical examination in suspected disorders of the shoulder

Movements at the shoulder

In examining shoulder movements it is important to determine how much of the movement occurs at the gleno-humeral joint and how much is contributed by rotation of the scapula. An accurate distinction between the two types of movement can be made only by grasping the lower half of the scapula so that its movements can be detected (Fig. 14.1). In the normal shoulder about half the range of abduction occurs at the gleno-humeral joint and half by scapular rotation. Disorders of the shoulder generally cause restriction of gleno-humeral movement rather than of scapular movement. If the shoulder joint proper (the gleno-humeral joint) is fused, either naturally or by operation, a range of abduction of up to 60 or 80 ° is possible by scapular movement alone.

Fig. 14.1 (left) Examining shoulder abduction. One hand grasps the scapula while the other steadies the elbow. In this way the proportion of the total range contributed by gleno-humeral movement and by scapular rotation can be assessed.

Stand behind the patient. Abduction: Instruct the patient to try to raise both arms sideways from the body so that the palms of the hands meet above the head. Measure the range, and observe what proportion of the movement takes place at the gleno-humeral joint and how much is contributed by rotation of the scapula upon the thorax. Flexion: Instruct the patient to raise the arms forwards towards the vertical. Again observe (by means of the hand upon the scapula) what proportion of the movement occurs at the gleno-humeral joint and how much is contributed by rotation of the scapula on the chest wall. Extension: Ask the patient to raise the elbows backwards. Lateral (external) rotation: The elbows are held in to the sides and are flexed 90 ° (Fig. 14.2): the forearms then serve as convenient pointers to indicate the angle of rotation (normal range = 80 °). Medial (internal) rotation: Instruct the patient to place the back of his hand in contact with his lumbar region and to carry the elbow forwards, bringing the finger tips up as high as possible between the shoulder blades (normal range = 110 °).

Fig. 14.2 (right) Examining shoulder rotation. The elbow is supported by the examiner’s hand and flexed to the right angle to eliminate forearm rotation. The forearm thus serves as a pointer to indicate the range of rotation at the shoulder.

Estimation of muscle power

In estimating the power of the shoulder muscles two groups must be distinguished:

The cervico-scapular and thoraco-scapular muscles. These control movements of the scapula. Estimate the power of each group in turn and compare on the two sides. Elevators of the scapula (levator scapulae, upper fibres of trapezius): Instruct the patient to shrug the shoulders against the resistance of the examiner’s hands. Retractors of the scapula (rhomboids and middle fibres of trapezius): Instruct the patient to brace the shoulders back. Abductor-rotators of the scapula (serratus anterior, with middle and lower fibres of trapezius): Instruct the patient to push horizontally forwards with the hand against a wall (Fig. 14.3) or simply to raise the arm from the side. If the serratus anterior is weak, winging of the scapula (backward projection of its vertebral border) will be observed (Fig. 14.3).

Fig. 14.3 Examination for weakness of the serratus anterior. If the serratus anterior is weak or paralysed winging of the scapula occurs when the arm is raised from the side or pushed forward against resistance.

The scapulo-humeral muscles. These control movements of the gleno-humeral joint. Estimate the power of each muscle group, testing in turn the abductors, adductors, flexors, extensors, lateral rotators, and medial rotators. If the patient has lost the power to initiate active gleno-humeral movement from the dependent position, determine whether he can maintain abduction when the limb has been raised with assistance to 90 °. Ability to sustain abduction but not to initiate it is characteristic of isolated rupture of the supraspinatus tendon (see Fig. 14.12, p. 267).

Fig. 14.12 Complete tear of tendinous cuff (torn supraspinatus). A Active abduction from the resting position is possible only by scapular rotation, the deltoid being unable to initiate gleno-humeral abduction without the help of the supraspinatus. B When the limb is raised passively beyond the horizontal abduction can be sustained actively by the deltoid.

The acromio-clavicular and sterno-clavicular joints

The clavicle may be regarded as a link, jointed at each end, connecting the scapula to the sternum (Fig. 14.4). Movement of the scapula must occur about a fulcrum at one or both ends of this link. In the normal shoulder movement of the scapula, with consequent movement at the acromio-clavicular and sterno-clavicular joints, occurs mainly:

Fig. 14.4 The mechanics of scapular rotation. The clavicle serves as a link, jointed at each end, by which the scapula is held away from the sternum. Full rotation of the scapula entails movement both at the acromio-clavicular joint and at the sterno-clavicular joint.

To examine the acromio-clavicular and sterno-clavicular joints stand in front of the patient. Examine the joints on each side for deformity, swelling, increase of local temperature, local tenderness, and pain on movement – especially at the extremes of elevation of the arm and backward bracing of the shoulders. Observe whether there is any tendency to subluxation or dislocation of the joint on movement.

Radiographic examination

Gleno-humeral joint. The routine shoulder film is a plain antero-posterior projection with the limb in the anatomical position. When additional information is required a special axillary projection with the arm abducted 90 ° (giving a lateral view of the humerus) should be obtained. Further films showing the upper end of the humerus in varying degrees of rotation are sometimes informative. Arthrography, after injection of radio-opaque fluid into the joint, will show whether or not the capsule is intact.

Acromio-clavicular joint and sterno-clavicular joint. Special projections are used to show each of these joints.

Other imaging techniques

Radioisotope scanning, computerised tomography, ultrasonography, and magnetic resonance imaging must each be considered in appropriate circumstances. Double contrast arthrography combined with computerised tomography or magnetic resonance imaging may be particularly valuable in demonstrating the extent of soft tissue damage in recurrent dislocation of the shoulder (see Fig. 14.10).

Fig. 14.10 Axial MR arthrogram of a patient with recurrent anterior shoulder dislocation. The large arrow indicates the presence of a bony defect (Hill-Sachs lesion) in the humeral head posteriorly. The smaller arrow points to a defect in the anterior cartilaginous labrum of the glenoid (the Bankart lesion). This has allowed the escape of contrast medium beneath the lax anterior capsule and predisposes the patient to further episodes of anterior dislocation.

Arthroscopy

Arthroscopy has become a well’established method of investigation for difficult shoulder problems, as well as being used increasingly for closed operative treatment. The use of both anterior and posterior portals allows direct access to the glenoid fossa, the capsule, and the articular surfaces, as well as the rotator cuff musculature and sub-acromial space.

Extrinsic sources of shoulder and arm pain

In many cases in which the main complaint is of pain in the shoulder or arm there is no local abnormality, the symptoms being referred from a lesion elsewhere. Thus pain over the shoulder is a common symptom in affections of the neck, especially when the brachial plexus or its roots are involved. Shoulder pain is also a feature of irritative lesions in contact with the diaphragm, either in the thorax or in the abdomen. The possibility of such extrinsic lesions must always be considered in the investigation of shoulder pain.

Fortunately, with careful interrogation and clinical examination there is little difficulty in distinguishing intrinsic from extrinsic lesions. The important point is that intrinsic lesions of the shoulder always give rise to local physical signs that are readily demonstrable on examination. If the shoulder is clinically normal it is improbable that it is the seat of disease, and attention should be directed towards possible sources of referred pain.