1444 



CLINICAL AND TOPOGRAPHICAL ANATOMY 



To stretch the nerve, an incision about three inches long is made in the line of the nerve, 

 beginning about 3.7 cm. (I5 in.) below the gluteus maximus. The long head of the biceps which 

 covers the nerve trunk and which is descending mediolaterally, is drawn medially. If the 

 nerve is exposed lower down, the interval between the hamstrings is identified and these muscles 

 drawn aside. The perineal branch of the posterior cutaneous (inferior pudenal) perforates 

 the deep fascia about 2.5 cm. (1 in.) in front of the tuber ischii, and turns forward to supply the 

 genitals. 



Superior gluteal artery. — If a line be drawn from the posterior superior spine to the apex 

 of the great trochanter, the limb being slightly flexed and rotated medially, the point of emer- 

 gence of the artery from the upper part of the great sacro-sciatic notch will correspond with the 

 junction of the upper and middle third of this line. (MacCormac.) The gluteal nerve emerges 

 immediately below the artery, and sends branches into the deeper portion. 



Inferior gluteal (sciatic) and pudic arteries. — The Umb being rotated medially, a line is 

 drawn from the posterior superior spine to the lateral part of the tuber ischii. The point of exit 

 of the above arteries will correspond to the junction of the middle and lower thirds of this line. 

 (MacCormac.) 



THE KNEE 



Bony landmarks. — The patella, the condyles of the femur, the condyles and 

 tuberosity of the tibia, the head of the fibula, are all easily examined. 



Fig. 1162. 



-The Gluteal Region, with the Superior and Inferior Gluteal and Pudic 



Arteries. 



Gluteus medius, turned up 



Inferior gluteal nerve 

 Gluteus maximus, cut 

 Medial circumflex artery 

 Obturator externus 



Insertion of gluteus medius 

 Lateral circumflex artery 



Gluteus minimus 



Muscular branches of inferior gluteal artery 

 Deep branch of superior gluteal artery 

 Superior gluteal nerve 



Piriformis perforated by peroneal 

 portion of sciatic nerve 



Cut edge of gluteus maximus 



Insertion of 

 gluteus maximus 



First perforating artery 



Quadratus fenioris 

 Branch of internal circumflex artery 

 Obturator internus with the two gem'elli 



I Pudic artery and nerve 

 Inferior gluteal artery 



I Semi-tendinosus 

 ' Semi-membranosus 

 Posterior cutaneous nerve 

 Arteria comitans nervi ischiadic! 

 Tibial portion of sciatic nerve 

 Perineal branch of posterior cutaneous 



Perineal portion of sciatic 

 (From a dissection by W. J. Walsham in St. Bartholomew's Hospital Museum.) 

 The muscular branch of the inferior gluteal (sciatic) artery has been drawn inward over the 

 tuber ischii with the reflected origin of the gluteus maximus muscle. 



The patella. — The limb being supported in the straight position, and the exten- 

 sor muscles relaxed, the natural range of mobility laterally of the patella can be 

 estimated. This is interfered with by muscular action in inflammatory conditions, 



