THE BACK OF THE THIGH. 1211 
indicated by a well-marked furrow, extending from the lower edge of the insertion 
of the gluteus maximus to the outer aspect of the knee; behind this furrow is the 
biceps, and in front of it is the large vastus externus, covered by the strong ilio- 
tibial portion of the fascia lata. The shaft of the femur inay be cut down upon 
along the whole length of this furrow with least injury to the soft parts; the trigone 
of the femur and deep-seated popliteal abscesses are most conveniently reached 
through the lower part of the same incision. The course of the great sciatic nerve 
corresponds to the upper half of a line extending froma point midway between 
the tuberosity of the ischium and the great trochanter to the centre of the popliteal 
space. The nerve enters the thigh under cover of the outer border of the biceps, 
whereas the small sciatic, which takes the same line, descends superficial to the 
biceps, between it and the fascia lata. In the operation of stretching the great 
sciatic the nerve is cut down upon immediately below the lower border of the 
Quadriceps extensor tendon —_Z a 
The r 
Gi ISSN 
Synovial pouch of knee— 
Subsynovial fat 
Vastus externus — ofthe 
Ilio-tibial band— if 
Superior external | | 
articular artery 
“y;, Vastus internus 
Adductor tubercle 
Deep branch of 
— — anastomotica magna 
\ | artery 
Tendon of adductor 
magnus 
Fat—4 
Popliteal artery - | | 
Biceps — 
Popliteal vein —(\ 
External popliteal nerve aie ek 
Internal popliteal nerve 
Lymphatic gland- 
Gracilis 
Semimembranosus Semitendinosus 
Fic. 816.—SEcTION THROUGH THE THIGH IMMEDIATELY ABOVE THE PATELLA. 
gluteus maximus. The surgeon, standing on the side of the patient opposite to 
the leg to be operated upon (Chiene), makes an incision in the line of the nerve 
through the integuments and fascia lata, and, sweeping the index - finger 
round the outer border of the biceps, hooks up the nerve as it hes between that 
muscle and the adductor magnus. The external popliteal nerve may be rolled under 
the finger as it descends immediately behind the tendon of the biceps and the head 
of the fibula; so close is the nerve to the tendon that the latter should be divided, im 
cases where this is necessary, by the open method, rather than subcutaneously. 
Abscesses may reach the flexor compartment of the thigh from various sources, viz. : (1) from 
the posterior aspect of the hip-joint ; (2) from the pelvis through the great sacro-sciatic foramen ; 
(3) from one or other of the bursxe under the gluteus maximus; (4) from the front of the hip-joint 
by passing backwards under the tensor fascize femoris ; or by winding backwards beneath the neck 
of the femur, and through the interval between the quadratus femoris and the adductor magnus ; 
(5) from the iliac fossa under Poupart’s ligament into Scarpa’s triangle, and thence to the back of 
the thigh by one or other of the routes already mentioned ; (6) the pus may spread upwards from 
the trigone of the femur, the knee, a popliteal gland, or from a bursa. 
.- Se 
