Chap. XL] 



UPPER END OF HUMERUS. 



201 



displacement, however, is by no means constant. 

 Pean, Anger, and others maintain that the usual 

 deformity is a projection of the upper end of the lower 

 fragment forwards, and that this deviation is due to 

 the nature and direction of the violence, and not to 

 muscular action. In some cases there is no displace- 

 ment, the broken ends being retained in situ, pro- 

 bably, by the biceps tendon and the long head of the 

 triceps. In at least one instance (Jarjavay) the lower 

 fragment was so drawn upwards and outwards, 

 apparently by the deltoid, as to nearly pierce the skin 

 of the shoulder. Hamilton comes to the general con- 

 clusion " that com- 

 plete or sensible 

 displacement is 

 less common at 

 this fracture than 

 in most other frac- 

 tures," and in this 

 conclusion many 

 surgeons agree. 



Amputation 

 at the shoulder 

 joiut. "Flap 

 method ; " " del- 

 toid flap." In the 

 outer flap are only 

 the deltoid and a 

 few small vessels 

 derived from the 

 acromio - thoracic 

 and the two cir- 

 cumflex arteries. 

 The cephalic vein 

 and descending 

 branch of the acromio - thoracic artery are in the 

 inner flap. The anterior and posterior borders of the 



Fig. 21. Amputation at Shoulder-joint (flap 



method) (Agatz). 

 a, Glenoid cavity ; 6, deltoid ; c, long head of 



biceps ; d, pectoralis major ; e, biceps and coraco- 



brachialis ; /, latissimus dorsi and teres major ; 



g, triceps ; 1, axillary vessels ; 2, circumflex 



vessels ; 3, brachial plexus. 



