156 SURGICAL ANATOMY OF 



and musculo-spiral, and in the lower third of the ulnar 

 and radial. 



The musculo-spiral enters the forearm between the 

 brachialis anticus and supinator longus, and after break- 

 ing up in the supinator brevis is distributed to the ex- 

 tensors and supinators; the median enters the forearm 

 between the two heads of the pronator teres and is ac- 

 companied by a vessel, the comes brevis mediani, which 

 is occasionally of considerable size, and may form one of 

 the chief supplies to the palm ; the ulnar enters the fore- 

 arm between the two heads of the flexor carpi ulnaris, 

 and accompanies the artery of the same name. 



In amputation through the upper third of the forearm 

 the flaps would contain the structures as follows : In the 

 anterior, integument and superficial veins and nerves, 

 the flexor carpi radialis, supinator longus, pulmaris lon- 

 gus, flexor carpi ulnaris, extensor carpi radialis longior, 

 pronator teres, flexor sublimis and profundus, and the 

 radial, ulnar, and anterior interosseous vessels and nerves. 

 The posterior , the extensor carpi radialis brevior, supi- 

 nator brevis, and the ulnar and common extensor of the 

 fingers, with the posterior interosseous vessels and nerves, 

 integuments, and superficial veins and nerves. The 

 vessels requiring ligature are the radial and ulnar, which 

 will be found just beneath the integument, the anterior 

 and posterior interosseous, which retract along the inter- 

 osseous membrane, and perhaps the comes nervi mediani. 



In performing the flap amputation the bones should 

 be placed midway between pronation and supination ; 

 and in cases of fracture of one or both bones, the same 

 position must be maintained, as they are then most nearly 

 parallel and furthest separated from each other, and there 

 is less chance of any union between them. Moreover, 



