322 



SURGICAL ANATOMY. 



Fig. 182. Fracture of the Humerus above the 

 Condyles. 



In fracture of the shaft of the Immerus, 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 inwards by the first-mentioned muscles, and the lower fragment 

 drawn upwards and outwards 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 fragments may be readily 

 brought into apposition by extension from the elbow, and retained in that position by adopting 

 -the same means as in the preceding injury. 



In fracture 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 the fracture occurs 

 in a transverse direction, only slight displacement occurs, the upper fragment being drawn a 

 little forwards ; but in oblique fracture, the combined actions of the Biceps and Brachialis anticus 

 muscles in front, and the Triceps behind, draw upwards the lower fragment, causing it to glide 

 over the upper fragment, either backwards or forwards, according to the direction of the fracture. 

 Simple extension reduces the deformity, and the application of splints on the four sides of the 

 arm retains the fragments in apposition. Care should be taken pot to raise the elbow, but the 

 forearm and hand may be supported in a sling. 



Fracture of the humerus (fig. 182) immediately above the condyles deserves very attentive 



consideration, as the general appearances cor- 

 respond somewhat with those produced by 

 separation of the epiphysis of the humerus, 

 and with those of dislocation of the radius 

 and ulna backwards. If the direction of the 

 fracture is oblique from above, downwards, 

 and forwards, the lower fragment is drawn 

 upwards and backwards by the Brachialis 

 anticus and Biceps in front, and the Triceps 

 behind. This injury may be diagnosticated from 

 dislocation, by the increased mobility in frac- 

 ture, the existence of crepitus, and the de- 

 formity being remedied by extension, by the 

 discontinuance of which it is again reproduced. 

 The age of the patient is of importance in 

 distinguishing this form of injury from sepa- 

 ration of the epiphysis. If fracture occurs 

 in the opposite direction to that shown in 

 the accompanying figure, the lower fragment 

 is drawn upwards and forwards, causing a 

 considerable prominence in front; and the 

 upper fragment projects backwards beneath 

 the tendon of the Triceps muscle. 



Fracture of the c or onoid process of the ulna 

 is an accident of rare occurrence, and is 

 usually caused by violent action of the Bra- 

 chialis anticus muscle. The amount of dis- 

 placement varies according to the extent of the fracture. If the tip of the process only is 

 broken off, the fragment is drawn upwards by the Brachialis anticus on a level with the 



coronoid depression of the humerus, and 

 the power of flexion is partially lost. If 

 the process is broken off near its root, the 

 fragment is still displaced by the same 

 muscle ; at the same time, on extending 

 the forearm, partial dislocation backwards 

 of the ulna occurs from the action of the 

 Triceps muscle. The appropriate treat- 

 ment would be to relax the Brachialis an- 

 ticus by flexing the forearm, and to retain 

 the fragments itt apposition by keeping 

 the arm in this position. Union is generally 

 ligamentous. 



Fracture of the olecranon process (fig. 

 183) is a more frequent accident, and is 

 caused either by violent action of the 

 Triceps muscle, or by a fall or blow upon 

 the point of the elbow. The detached 

 fragment is displaced upwards, by the 

 action of the Triceps muscle, from half an 

 inch to two inches ; the prominence of the 

 elbow is consequently lost, and a deep 

 hollow is felt at the back part of the joint, which is much increased on flexing the limb. The 



Fig. 183. Fracture of the Olecranon. 



