OF THE MUSCLES OF THE UPPER EXTREMITY. 321 



Fig. ISO. Fracture of the Middle of the 

 Clavicle. 



wards, and, together with the scapula, raised upwards to a level with the inner fragment, and 

 retained in that position. 



In fracture of the acromial end of the cla- 

 vicle between the conoid and trapezoid liga- 

 ments, only slight displacement occurs, as 

 these ligaments, from their oblique insertion, 

 serve to hold both portions of the bone in 

 apposition. Fracture, also, of the sternal end, 

 internal to the costo-clavicular ligament, is 

 attended with only slight displacement, this 

 ligament serving to retain the fragments in 

 close apposition. 



Fracture of the acromion process usually 

 arises from violence applied to the upper and 

 outer part of the shoulder; it is generally 

 known by the rotundity of tho shoulder being 

 lost, from the Deltoid drawing downwards and 

 forwards the fractured portion ; and the dis- 

 placement may easily be discovered by tracing 

 the margin of the clavicle outwards, when the 

 fragment will be found resting on the front 

 and upper part of the head of the humerus. 

 In order to relax the anterior and outer fibres 

 of the Deltoid (the opposing muscle), the arm 

 should be drawn forwards across the chest, 

 and the elbow well raised, so that the head 

 of the bone may press upwards the acromion 

 process, and retain it in its position. 



Fracture of the coracoid process is an ex- 

 tremely rare accident, and is usually caused 

 by a sharp blow on the point of the shoulder. 

 Displacement is here produced by the com- 

 bined actions of the Pectoralis minor, short 

 head of the Biceps, and Coraco-brachialis, the former muscle drawing the fragment inwards, the 

 latter directly downwards, the amount of displacement being limited by the connection of this 

 process to the acromion by means of the coraco-acromial ligament. In order to relax these 

 muscles, and replace the fragments in close apposition, the forearm should be flexed so as to 

 relax the Biceps, and the arm drawn forwards and inwards across the chest so as to relax the 

 Coraco-brachialis ; tne humerus should then be pushed upwards against the coraco-acromial 

 ligament, and the arm retained in this position. 



, Fracture of the anatomical neck of the humerus within the capsular ligament is a rare accident, 

 attended with very slight displacement, an impaired condition of the motions of the joint, and 

 crepitus. 



Fracture of the surgical neck (fig. 181) is very common, is attended with considerable displace- 

 ment, and its appearances correspond somewhat with those of dislocation of the head of the 

 humerus into the axilla. The upper fragment 

 is slightly elevated under the coraco-acromial 

 ligament by the muscles attached to the 

 greater and lesser tuberosities ; the lower 

 fragment is drawn inwards by the Pectoralis 

 major, Latissimus dorsi, and Teres major; 

 and the humerus is thrown obliquely outwards 

 from the side by the Deltoid, and occasionally 

 elevated so as to project beneath and in front 

 of the coracoid process. By fixing the shoul- 

 der, and drawing the arm outwards and 

 downwards, the deformity is at once reduced. 

 To counteract the action of the opposing 

 muscles, and to keep the fragments in posi- 

 tion, the arm should be drawn from the side, 

 and pasteboard splints applied on its four 

 sides ; a large conical-shaped pad should be 

 placed in the axilla with the base turned 

 upwards, and the elbow approximated to the 

 side, and retained there by a broad roller 

 passed round the chest ; the forearm should 

 then be flexed, and the hand supported in a 

 sling, care being taken not to raise the elbow, 

 otherwise the lower fragment may be displaced 

 upwards. 



21 



Fig. 181. Fracture of the Surgical Neck 

 of the Humerus. 



