342 Anatomy Applied to Medicine and Sutgery. 



formis, and the upper margin of the sciatic notch is identi- 

 fied, and the artery sought for, at this point, and ligated. 



Operations on the Nerves. The anterior crural, as 

 already mentioned, lies about half an inch external to the 

 femoral artery at Poupart's ligament. To expose it, make 

 a vertical incision in the line of the nerve, dividing the 

 superficial circumflex iliac vessels and the crural branch 

 of the genito-crural nerve. The deep fascia is then in- 

 cised and the nerve sought for, immediately below Pou- 

 part's ligament, between the psoas and iliacus muscles. 

 The great sciatic is situated on the back of the thigh. It 

 extends from its exit from the pelvis, at the lower border 

 of the pyriformis muscle, to a point, a little below the mid- 

 dle of the thigh, where it generally divides into internal 

 and external popliteal nerves. The great sciatic is cover- 

 ed by the gluteus maximus and the hamstring muscles, 

 and rests on the external rotators and on the adductor 

 magnus. (The small sciatic nerve is in the same line as 

 the great sciatic, but superficial to it.) To expose the 

 great sciatic nerve for the purpose of stretching it, make 

 an incision, a little external to the course of the nerve. 

 After incising the superficial and deep fasciae, the lower 

 border of the gluteus maximus is exposed and drawn up- 

 wards, the hamstring muscles next present themselves 

 and should be drawn inwards, the knee having been pre- 

 viously flexed to relax them, and the nerve will be found 

 lying beneath these muscles. 



Amputation of the Thigh. General Considerations. 

 The integument of the thigh is loosely attached to the 

 subjacent tissues, and hence, retraction of the skin flaps, in 

 amputation, is pronounced. Along the groove between 

 the vastus externus and the hamstring muscles, however, 

 the skin is more firmly united to the deeper parts. In a sec- 

 tion through the thigh, at its upper third, the bone is even- 



