tHE LOWER LIMB 5$^ 



The gluteus maximus should be cleaned in the direction of its coarse 

 fasciculi, and in connection with its lower border the bursa between it and 

 the tuber ischii should be displayed. The muscle is to be divided about ij 

 inches from its origin. As the greater part of it is being reflected outwards, 

 the follo\N'ing arteries should be exposed entering its deep surface : the 

 superficial branch of the gluteal, the inferior gluteal branch of the sciatic, 

 and branches of the first perforating of the arteria profunda femoris. The 

 inferior gluteal nerve should also be shown entering the deep surface of 

 the muscle in its lower third. Between the great trochanter and the 

 insertion of the muscle into the fascia lata a large multilocular bursa 

 will be found, and another single bursa should be noticed between its insertion 

 and the vastus extemus just below the great trochanter. The twofold inser- 

 tion of the muscle should be noted. The origin of the muscle is now to be 

 removed so as to expose the great sacro-sciatic Ugament and the structures 

 piercing it, namely, the coccygeal branch of the sciatic artery, the sacral 

 branch of the internal pudic arterj', and the perforating cutaneous branch of 

 the sacral plexus of nerves. On the superficial surface of the Ugament will be 

 found the plexiform loops formed by the external branches of the posterior 

 primary divisions of the first three sacral nerves. 



The fascia lata should next be removed from the anterior part of the 

 gluteus medius, and in doing so it should be noted that the superficial 

 fibres of the muscle arise from the deep surface of the fascia. The various 

 structures underneath the gluteus maximus are to be cleaned from above 

 downwards, as follows : the posterior fleshy part of the gluteus medius, 

 gluteal vessels, pyriformis, great and small sciatic nerves, sciatic vessels, 

 pudic nerve and internal pudic vessels, nerve to the obturator intemus, 

 furnishing a branch to the gemellus superior, common nerve to the gemellus 

 inferior and quadratus femoris, gemellus superior, tendon of the obturator 

 intemus, gemellus inferior, quadratus femoris, upper horizontal part of the 

 adductor magnus, origins of the hamstring muscles from the tuber ischii, 

 and the upper tendinous fibres of the vastus extemus. The digital and 

 crucial anastomoses should be looked for, the former in the digital or tro- 

 chanteric fossa, and the latter between the quadratus femoris and adductor 

 magnus. 



The small sciatic nerve should be displayed so as to show its long pudendal 

 branch, and the great sciatic nerve is to be exposed in the hollow between . 

 the tuber ischii and the great trochanter. The sciatic artery and its branches 

 are to be followed out. The pudic nerve, the internal pudic vessels, and 

 the nerve to the obturator intemus (with its branch to the gemellus superior) 

 are to be shown as they cross the back of the spine of the ischium. The 

 tendon of the obturator intemus should be divided to show the columns on 

 its under surface, the synovial bursa between the tendon and the small 

 sciatic notch, and the cartilage facing that notch, with its grooves and 

 ridges for the columns of the tendon. The sacro-sciatic Ugaments, great and 

 small, should be studied. The mode of formation of the great and small 

 sacro-sciatic foramina should be made out, and the various structures passing 

 through each should be noted. The upper border of the quadratus femoris is 

 to be displaced downwards so as to show the obturator externus and the 

 ascending branch of the internal circumflex artery, both on their way to the 

 digital fossa. The lower border of the quadratus femoris should be raised to 

 show the small trochanter and the insertion of the ilio-psoas in part. The 

 common nerve to the gemellus inferior and quadratus femoris wiU be found 

 at first underneath the great sciatic nerve, and subsequently passing beneath 

 the gemelh, obturator internus, and quadratus femoris. Its articular branch 

 to the hip-joint should be looked for. If absent, its place will be taken by a 

 branch from the great sciatic nerve. 



The gluteus medius (except its anterior fibres) should now be stripped from 

 the dorsum ilii, and the bone cleaned by scraping, so as to show the exact 

 bony origin of the muscle. The pyriformis being also divided, the gluteus 

 minimus is to be cleaned, along with the upper and lower branches of the 

 deep divisions of the gluteal artery and superior gluteal nerve. One of each 



38 



