THE SHOULDER REGION 23 



The articular head now looks directly forwards, and if the 

 tear has spread to the anterior aspect of the capsule, the tendon 

 of the subscapularis, rendered tense by the excessive lateral 

 rotation, may press the bone back into place. 



If reduction does not occur at this stage, the elbow is carried 

 forwards and medially, lateral rotation of the humerus being 

 maintained through the position of the forearm. This move- 

 ment of flexion and adduction stretches the capsule by tilting 

 the greater tubercle backwards, and at this stage the head 

 often passes back into place. Should it not do so, the patient's 

 forearm is rapidly swung over towards the opposite shoulder 

 to produce medial rotation of the humerus. If the elbow is 

 elevated slightly during this movement, the head of the humerus 

 descends, as it rotates medially, and passes through the torn 

 inferior part of the capsule. 



In testing passive movements or the limitations of movements 

 following injury in the region of the right shoulder- joint, the 

 surgeon stands behind the patient and holds the semi-flexed 

 elbow of the affected side in his own right palm. This enables 

 him to move the humerus at the shoulder- joint in any way he 

 desires, while the left hand examines the injured region. The 

 left shoulder is examined with the positiont>f the hands reversed. 



Complications. Dislocation of the shoulder may be 

 complicated by the tearing off of a part of the greater tubercle. 

 If the fragment includes the insertion of the supra-spinatus, it 

 is drawn upwards and subsequently limits abduction by becoming 

 jammed beneath the acromion. 



Fracture through the anatomical or surgical neck is a rare 

 but important complication. The head of the humerus can be 

 palpated through the superficial infra-clavicular triangle or 

 beneath the coracoid process ; but the diagnosis of the fracture 

 will be determined if movement of the humeral shaft produces 

 no effect on the head. Owing to the small size of the proximal 

 fragment manipulative methods of reduction rarely succeed, 

 and operative measures usually have to be adopted, the joint 

 being approached from in front (p. 19). 



Injuries to the brachial nerves following dislocation of the 

 shoulder are described on pp. 98-101. 



Attempts to reduce old-standing dislocations of the shoulder 

 may cause rupture of the axillary artery and stretching or 

 laceration of the brachial plexus, owing to the presence of 

 adhesions between the head of the humerus and the axillary 



