THE GLUTEAL REGION. 



427 



3 I .3 / 3. Back of thigh. 



2. Popliteal space. 



Back of leg. 



portion, terminate in a thick tendinous lamina, which passes across the great trochanter 

 and is inserted into the fascia lata covering the outer side of the thigh ; the deeper 

 fibres of the lower portion of the muscle are in- 

 serted into the rough line leading from the great 

 trochanter to the Tinea aspera between the Vas- 

 tus externus and Adductor magnus. 



Three synovial bursce are usually found in re- 



lation with this muscle. One of these, of large ll ^ \ 1. Dissection of 



size, and generally multilocular, separates it fj|/ / \ gluteal region. 

 from the great trochanter. A second, often 

 wanting, is situated on the tuberosity of the 

 ischium. A third is found between the tendon 

 of this muscle and the Vastus externus. 



Relations. By its superficial surface, with 

 a thin fascia, which separates it from the sub- 

 cutaneous tissue ; by its deep surface, from 

 above downward, with the ilium, sacrum, coccyx, 

 and great sacro-sciatic ligament, part of the 

 Gluteus medius, Pyriformis, Gemelli, Obturator 

 internus, Quadratus femoris, the tuberosity of 

 the ischium, great trochanter, the origin of the 

 Biceps, Semitendinosus, Semimembranosus, and 

 Adductor magnus muscles. The superficial part 

 of the gluteal artery reaches the deep surface 

 of the muscle by passing between the Pyriformis 

 and the Gluteus medius ; the sciatic and internal 

 pudic vessels and nerves and muscular branches 

 from the sacral plexus issue from the pelvis be- 

 low the Pyriformis. The first perforating artery 

 and the terminal branches of the internal cir- 



cumflex artery are also found under cover of the I s \ 5 Sole of foot 



muscle. Its upper border is thin, and connected 

 with the Gluteus medius by the fascia lata. Its 

 lower border is free and prominent. 



Dissection. Divide the Grluteus maximus near 

 its origin by a vertical incision carried from its upper 

 to its lower border ; a cellular interval will be ex- 

 posed, separating it from the Gfluteus medius and External rotator muscles beneath. The 

 upper portion of the muscle is to be altogether detached, and the lower portion turned out- 

 ward ; the loose areolar tissue filling up the interspace between the trochanter major and tuber- 

 osity of the ischium being removed, the parts already enumerated as exposed by the removal 

 of this muscle will be seen. 



The Gluteus medius is a broad, thick, radiated muscle, situated on the outer 

 surface of the pelvis. Its posterior third is covered by the Gluteus maximus ; its 

 anterior two-thirds by the fascia lata, which separates it from the integument. It 

 arises from the outer surface of the ilium, between the superior and middle curved 

 lines, and from the outer lip of that portion of the crest which is between them ; 

 it also arises from the dense fascia (Gluteal aponeurosis) covering its outer surface. 

 The fibres converge to a strong flattened tendon which is inserted into the oblique 

 line which traverses the outer surface of the great trochanter. A synovial bursa 

 separates the tendon of the muscle from the surface of the trochanter in front of 

 its insertion. 



Relations. By its superficial surface, with the Gluteus maximus behind, the 

 Tensor fasciae femoris and deep fascia in front ; by its deep surface, with the Glu- 

 teus minimus and the gluteal vessels and superior gluteal nerve. Its anterior border 

 is blended with the Gluteus minimus. Its posterior border lies parallel with the 

 Pyriformis, the gluteal vessels intervening. 



FIG. 255. Dissection of lower extremity. 

 Posterior view. 



