ARM. 



brachial artery usually preserves its ordinary biceps, coraco-bracbialis, and triceps. Frac- 

 relations to the surrounding parts, while the tures of that portion of the humerus which is 

 supernumerary trunk lies to its internal side covered by the brachioeus anticus in front and 

 and takes a more superficial course, some- the triceps behind, are often unattended by 

 times getting above the fascia of the arm, as any very obvious displacement, in consequence 

 we haVe witnessed in a few rare cases. It of these muscles being inserted into both frag- 

 occasionally happens that the brachial artery ments ; fractures near the elbow are occa- 

 divides at its commencement into two trunks, sionally followed by deformities presenting 

 which again unite at its lower part. It is ob- some of the characters of dislocations of the 

 vious that the surgeon, in performing operations elbow, of which more notice will be taken in 

 on this artery, should constantly bear in mind the article ELBOW. 



that it is subject to the above-mentioned irre- General inflammatory enlargement of the 



gularities, and that he should cautiously guard arm is rare ; it sometimes appears as a con- 



against committing the error of including the comitant affection with inflammation of the 



wrong vessel in his ligature. veins of the arm consequent on the operation 



The internal side of the arm in the middle of phlebotomy, in which case it not unfre- 



of its length is the most eligible place for quently happens that abscesses form along the 



making compression on the brachial artery ; course of the sheath of the brachial artery ; 



here this vessel is superficial, so that its pul- red streaks along the course of the lymphatics 



sation can be felt at once, whilst it has nothing and enlargement of the lymphatic glands are 



interposed between it and the bone but the sometimes present in consequence of disease 



tendinous insertion of the coraco-brachialis or inflammation affecting the hand or fore-arm, 

 muscle. It happens, however, that the median Amputation of the arm below the insertion 



nerve lies immediately over the artery in this of the deltoid may be performed either by the 



situation, a circumstance which causes com- circular incision or the double flap ; when the 



pression of the latter to be attended with con- latter method is practised, the flaps should be 



siderable pain, and productive of injury to the formed on the external and internal sides, by 



nerve if maintained for too great a length of time, which the more important vessels and nerves 



As the trunk of the brachial artery and will be included in the internal flap, 

 several large nerves traverse this part of the When circumstances require the performance 

 arm, it is obvious that wounds in this region of amputation above the insertion of the del- 

 are liable to be attended with more serious toid, the circular operation should never be 

 consequences than those of any other part of practised, for the following reason ; in order 

 the arm. A wound in the posterior region of to obtain a sufficiency of covering for the bone, 

 the arm may be attended with considerable the pectoralis major, latissimus dorsi, and teres 

 haemorrhage, if it should happen to penetrate so major would all be detached from their inser- 

 deep as to divide the profunda artery, or it may tions, a consequence of which would be that the 

 cause paralysis of the extensor muscles of the contractions of these muscles in opposite di- 

 hand and fingers by dividing the radial nerve. rections, by drawing asunder the edges of the 



When the humerus is fractured, the con- wound, would not only render complete appo- 

 sequent derangement of the fragments varies sition difficult in the first instance, but more- 

 according to the part at which the bone hap- over their continued action would have the 

 pens to be broken ; when fracture occurs im- effect of converting the wound into an ulcer, 

 mediately above the insertions of the pectoralis which it would be extremely difficult if not 

 major and latissimus dorsi, the lower fragment impossible to heal ; therefore, whenever we 

 is brought inward towards the axilla by the have to amputate so high up, it is the more 

 action of these muscles, and drawn upwards judicious mode of proceeding to make a flap 

 by the action of the deltoid, biceps, coraco- including so much of the deltoid muscle as 

 brachialis, and long head of the triceps, whilst will form a sufficient covering for the stump, 

 the extremity of the upper fragment is r?ther The importance of attending to the foregoing 

 turned outwards by the supra-spinatus. In circumstances was first pointed out by Louis, 

 cases where the humerus is fractured imme- the learned secretary to the French Academy 

 diately above the insertion of the deltoid and of Surgery.* 



below the attachments of the latissimus dorsi The arteries which require to be tied after 

 and pectoralis major, the deltoid will draw the amputation of the arm below the insertion of 

 lower fragment upwards and outwards, whilst the deltoid are the brachial and inferior pro- 

 the upper fragment will be drawn inwards funda on the internal side ; on the external side 

 towards the axilla by the pectoralis major and there are often two branches of the superior 

 latissimus dorsi. If the bone be broken im- profunda requiring a ligature, one of which 

 mediately below the insertion of the deltoid, accompanies the musculo-spiral nerve, and the 

 little or no displacement of the fragments may other runs in the substance of the triceps, 

 ensue, as the opposing forces exercised on the When it becomes necessary to tie the bra- 

 superior fragment by the deltoid on the ex- chial artery on account of a wound or aneu- 

 ternal side, and the pectoralis major and latis- rism, the varieties of its relation to the median 

 simus dorsi on the internal, pretty nearly nerve should be carefully borne in mind ; at 

 counterbalance each other; it more generally the upper part of the arm this artery has the 

 happens, however, that the upper fragment is median nerve external to it, and the ulnar 

 turned outwards by the preponderating action nerve to its inner side ; in the middle of the 

 of the deltoid upon it, whilst the lower frag- 

 ment is drawn upwards by the action of the * Memoires de TAcademie de Chirurgic, torn. v. 



