THE SHOULDER REGION n 



clavicles is rare, but from accounts of the recorded cases, the functional 



disability is slight. 



Excision of the Clavicle. Removal of the Middle Third 

 of the clavicle is commonly carried out as a preliminary step 

 in interscapulo-thoracic amputation, as it facilitates ligature of 

 the third part of the subclavian artery. The Whole Bone 

 may be excised most easily from acromial to sternal end. 



Examination of the Clavicle. In suspected injury of the 

 clavicle or of the acromion, the surgeon stands behind the patient 

 and compares the contours of the two shoulders. He next 

 places a hand on each side of the neck in such a way that the 

 tips of the fingers palpate the jugular (supra-sternal) notch 

 and the thumbs rest behind on the vertebral spines. The hands 

 are separated from one another so that the fingers pass over the 

 subcutaneous surfaces of the two clavicles. When the acromio- 

 clavicular joint is reached the fingers are carried forwards around 

 the anterior extremity of the acromion, and its subcutaneous 

 surface and lateral border may be palpated. 



Fractures of the Clavicle. Fracture of the sternal end of 

 the clavicle, medial to the costo-clavicular (rhomboid) ligament,, 

 is rare, and the displacement is not great unless the costo- 

 clavicular ligament is torn. When this occurs, the medial 

 end of the lateral fragment is drawn upwards by the sterno- 

 mastoid and the acromial end of the clavicle sinks downwards 

 owing to the weight of the arm. 



The common site of fracture is the point of union of the middle 

 and lateral thirds, where the bone is weak owing to the junction 

 of its two curves. It is the commonest of all fractures. One 

 third of the cases are of the greenstick variety and occur in 

 infancy. It is generally due to indirect violence from falls on 

 the hand, elbow, or shoulder, and the force is transmitted to 

 the clavicle through the glenoid cavity and the coraco-clavicular 

 ligament, or through the acromion. The direction of the 

 fracture is most constant it is downwards, medially, and 

 forwards. The displacement of the lateral fragment is in the 

 same direction, and the limb collapses medially and forwards 

 on to the trunk, consequent on the snapping of its prop. The 

 medial fragment is drawn upwards by the sterno-mastoid. It 

 is rare to find any injury to the subclavian vessels or to the 

 nerves of the brachial plexus, which all lie behind and below 

 the clavicle, because they are protected by the subclavius 

 muscle, which acts as a cushion between them and the broken 



