1442 CLINICAL AND TOPOGRAPHICAL ANATOMY 



by which the arterj' enters the upper and medial part of the popliteal space. The saphenous, 

 the largest branch of the femoral nerve, having crossed the femoral vessels latero-medially, 

 accompanies them as far as the opening in the adductor magnus. Here it perforates the aponeu- 

 rotic roof, and is prolonged under the sartorius, accompanied by the superficial part of the genu 

 suprema artery, to perforate the fascia lata between the sartorius and gracihs, and run with the 

 great saphenous vein at the upper and medial part of the leg. 



Pressure may be applied to the femoral arter}^ — (1) Immediately below the inguinal liga- 

 ment: it should here be directed backward so as to compress the vessel against the brim of the 

 pelvis and the capsule of the hip-joint; (2) at the apex of the femoral trigone the pressure here 

 being directed lateralh^ and a little backward, so as to command the vessel against the bone; 

 (3) in the adductor canal the pressure should be directed laterally with the same object. Care 

 must be taken, especially above, to avoid the vein, which lies very close to the artery, and also 

 the femoral nerve, which enters the thigh about 1.2 cm. {\ in.) outside the artery, and at once 

 breaks up into its branches, superficial and deep. 



In ligature of the femoral artery in Hunter's canal, the line of the incision, in the middle 

 third of the thigh, must exactly follow that of the vessel. It is frequently made too lateral, 

 exposing the vastus medialis. Branches of the saphenous vein being removed, the fascia lata 

 is slit up and the sartorius identified bj' its fibres descending medially. Those of the vastus 

 medialis are less oblique and are directed downward and laterally. The sartorius having been 

 drawn to the medial side, usually, the aponeurotic roof of the canal is opened, and the femoral 

 sheath identified. The vein, here posterior and to the lateral side, is closely connected to the 

 artery. 



The close contiguity of the femoral artery and vein accounts for the comparative frequency 

 of arterio-venous aneurysms especially in the upper part, where the vessels are easily wounded. 

 Their superficial position here further accounts for the facility with which malignant disease, 

 e. g., epitheliomatous glands, may cause fatal haemorrhage. Access to the femur. This is best 

 attained on the lateral side of the shaft along the line of the lateral intermuscular septum 

 (fig. 1160), the biceps being pulled backward, and the vastus lateralis detached anteriorly. On 

 the medial side the bone may be exposed by an incision starting from a point midway between 

 the inner margin of the patella and the adductor tubercle and passing obliquely upward and 

 laterally, but the parts here are more vascular. Fractures of the shaft usually occur about the 

 centre. The main tendency to displacement is of the lower fragment upward by the ham- 

 strings. The upper fragment is anterior; this is especially marked in the upper third, owing to 

 the action of the ilio-psoas, which also rotates the upper fragment laterally. In the lower third 

 the forward curve of the femur and its more superficial position explain the fact that it is here that 

 compound fractures of the femur may, occasionally, occur. Ossification. The unstable 

 nature of the tissues about the upper epiphysis, which appears at the end of the first year and 

 unites about eighteen, and the frequency of tuberculous disease in early life are well known. 

 In the lower epiphysis ossification begins before birth, a point of medico-legal importance in 

 deciding whether a newly born child has reached the full period of uterine gestation. From this 

 epiphysis, the level of which is denoted by a line drawn horizontally laterally from the adductor 

 tubercle, and the vascular growing tendon of the adductor magnus — the origin of an exostosis 

 is not uncommon. Displacement of this epiphysis (it unites about twenty) in boyhood and adol- 

 escence is a grave injury from the immediate risk of the popliteal vessels. The mischief is 

 usually done by overextension of the leg, as when this is caught in a rapidly moving carriage- 

 wheel; the epiphysis is carried forward in front of the diaphysis, the lower end of which is directed 

 backward, endangering the vessels which are posterior and closely adjacent. 



Amputation through the thigh.— This is usually performed in the lower third, by anterior 

 and posterior flaps, the former being the longer, so as to ensure a scar free from pressure, and 

 circular division of the muscles, vessels, and nerves. The vessels requiring attention are the 

 femoral, whi(;h lie at the medial side, and the more posteriorly, the lower the amputation; the 

 descending branch of the lateral circumflex, and the termination of the profunda near the 

 linea aspera. The femoral artery has a marked tendency to retract in the adductor canal. 

 Care should be taken not to include the saphenous nerve when the femoral vessels are tied, and 

 to cut the sciatic cleanly and high up. When amputation has to be performed in the upper 

 third of the thigh, the tendency of the ilio-psoas to flex the shortened limb and thus bring the 

 sawn femur against the end of the stump must be remembered, and met by keeping the patient 

 propi)('d up and the stump as horizontal as i)ossible. Some of the structures now divided are 

 shown in fig. IIGO. 



The buttocks. Bony landmarks. — The finger readily traces the whole outline 

 of the; iliac crest. Behind, it terminates in the posterior superior iliac spine, 

 which corresponds in level to the second sacral spine and the centre of the sacro- 

 iliac joint. (Holden.) 



The third sacral spine marks the lowest limit of the spinal membranes and the cerebro- 

 spinal fluid; it also corrcsjxmds to the ujjjx-r l)()rder of the great sacro-sciatic notch. The first 

 piece of the coccyx corresponds to the si)ine of the ischium. (Windle.) Its apex is in the furrow 

 just behind the last piece of the rectum. 



The tuberosities of the ischium arc; readily felt by deep pressure on either side 

 of the anus. In the erect position they are covered by the lower margin of the 

 gluteus maximus. In sitting they are protected by tough skin, fasciie, with coarse 

 fibrous fat, and often by a bursa known, according to the patients in whom it be- 

 comes enlarged, as weaver's, coachman's, lighterman's, tlrayman's bursa. The 



