412 



THE MUSCLES AND FASCIA. 



FIG. 246. Fracture of the middle of the 

 clavicle. 



In fracture of the acromial end of the clavicle, between the conoid and trapezoid ligaments, 

 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 liga- 

 ment, is attended with only slight displacement, this 

 ligament serving to retain the fragments in close appo- 

 sition. 



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 the 

 shoulder being lost, from the Deltoid drawing the frac- 

 tured portion downward and forward ; and the displace- 

 ment may easily be discovered by tracing the margin of 

 the clavicle outward, 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 forward across the chest and the elbow 

 well raised, so that the head of the bone may press the 

 acromion process upward and retain it in its position. 



Fracture of the coracoid process is an extremely rare 

 accident, and is usually caused by a sharp blow on the 

 point of the shoulder. Displacement is here produced 

 by the combined actions of the Pectoralis minor, short 

 head of the Biceps, and Coraco-brachialis, the former 

 muscle drawing the fragment inward, and the latter 

 directly downward, the amount of displacement being 

 limited by the connection of this process to the acromion 

 by means of the coraco-acromial ligament. In many 

 cases there appears to have been little or no displace- 

 ment, from the fact that the coraco- clavicular ligament 

 has remained intact, and has kept the separated fragment from displacement. In order to re- 

 lax these muscles and replace the fragments in close apposition, the forearm should be flexed so 

 as to relax the Biceps, and the arm drawn forward and inward across the chest, so as to relax 

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

 ligament, and the arm retained in that position. 



Fracture of the surgical neck of the humerus (Fig. 247) is very common, is attended with 

 considerable displacement, 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 inward by the Pectoralis major, Latissimus dorsi, and Teres major; and 

 the humerus is thrown obliquely outward from the side by the Deltoid, and occasionally elevated 

 so as to cause the upper end of the lower fragment to project beneath and in front of the cora- 



coid process. The deformity is reduced by fixing the shoulder, 

 and drawing the arm outward and downward. To counteract 

 the opposing muscles, and to keep the fragments in position, a 

 small conical-shaped pad should be placed in the axilla, and the 

 arm bandaged to the side by a broad roller passed round the 

 chest, in such a manner that the elbow is carried slightly for- 

 ward, so as to throw the upper end of the lower fragment 

 backward and outward toward the head of the bone. The 

 whole is then covered with a carefully moulded gutta-percha or 

 poroplastic shoulder cap. 



In fracture of the shaft of the humerus below the insertion 

 of the Pectoralis major, Latissimus dorsi. and Teres major, and 

 above the insertion of the Deltoid, there is also considerable 

 deformity, the upper fragment being drawn inward by the 

 first-mentioned muscles, and the lower fragment upward and 

 outward by the Deltoid, producing shortening of the limb and 

 a considerable prominence at the seat of fracture, from the 

 fractured ends of the bone riding over one another, especially 

 if the fracture takes place in an oblique direction. The frag- 

 ments may be brought into apposition by extension from the 

 elbow, and retained in that position by adopting the same 

 means as in the preceding injury. 



In fractures of the shaft of the humerus immediately below 



the insertion of the Deltoid, the amount of deformity depends greatly upon the direction of the 

 fracture. If it occurs in a transverse direction, only slight displacement takes place, the upper 

 fragment being drawn a little forward ; but in oblique fracture the combined actions of the 

 Biceps and Brachialis anticus muscles in front and the Triceps behind draw upward the lower 

 fragment, causing it to glide over the upper fragment, either backward or forward, accord - 



FIG. 247. Fracture of the surgical 

 neck of the humerus. 



