The femoral artery (femoralis s. cruralis ; French: artère fémorale ), is that portion of the artery of the lower limb which lies along the upper two-thirds of the thigh, — its limits being marked, above, by Poupart's ligament, and below, by the opening in the great adductor muscle, after passing through which the artery assumes the name popliteal.
A general idea of the direction of ihe femoral artery over the fore part and inner side of the thigh would be obtained by a line reaching from a point midway between the anterior superior spine of the ilium and the symphysis of the pubes to the inner side of the patella. But the situation of the vessel is best ascertained by observation of the surface at the upper part of the thigh, inasmuch as it lies along the middle of a depression formed between the muscles covering the femur on the outer side, and the adductor muscles on the inner side of the limb. In this situation the beating of the artery may be felt, and the circulation through the vessel be most easily controlled by pressure.
Owing to the natural curvature of the femur, and to the passage of the femoral artery from the front towards the back of the thigh, the relative position of the vessel and the bone varies considerably at different points. Thus, at the groin, the artery, after having passed over the margin of the pelvis, is placed in front of the head of the femur ; at its lower end, the vessel lies close to the inner side of the bone ; whilst in the intervening space, in consequence of the projection of the neck and shaft of the femur outwards, while the artery holds a straight course, the two are separated by a considerable interval.
Becoming deeper as it descends, the femoral artery is at first comparatively near the surface, being covered in the upper third of the thigh by the common integuments and the fascia lata, in addition to the sheath, which contains both the artery and the vein. In this situation, a triangular space may, on dissection, be recognised, upon the fore part of the thigh, immediately below the fold of the groin. The apex of this triangle is directed downwards, its sides are formed respectively by the sartorius and the long adductor muscles, and its base by the lower margin of the abdominal wall, which is represented by Poupart's ligament. This triangular interval is divided into two nearly equal parts by the femoral vessels, which extend from the middle of its base to its apex.
Below the part just referred to, the femoral artery is deeply placed, being covered by the sartorius muscle, which, after crossing obliquely from the outer to the inner side of the thigh, descends vertically and covers the artery to its end. The vessel is likewise covered, beneath the muscle, by a dense band of fibrous structure, which stretches across from the tendons of the long and great adductors to the vastus internus muscle.
The artery rests successively against the following parts. First, upon the psoas muscle, by which it is separated from the margin of the pelvis, and from the capsule of the hip-joint; next, upon, or rather in front of, the pectineus muscle, the deep femoral artery and vein being interposed; afterwards, upon the long adductor muscle; and lastly, upon the tendon of the great adductor, the femoral vein being placed between the tendon and the artery. At the lower part of its course, the femoral artery has immediately on its outer side the vastus internus muscle, which intervenes between it and the inner side of the femur.
The femoral vein is very close to the artery, both being enclosed in the same sheath, separated from each other only by a thin partition. At the groin, the vein lies on the same plane as the artery to its inner side; but gradually inclining backwards, it afterwards sinks behind that vessel, and even gets somewhat to its outer side. The deep femoral vein, near its termination, crosses behind the femoral artery, and the long saphenous vein, as it ascends on the fore part of the limb, lies to its inner side ; but it not unfrequently happens that a superficial vein of considerable size ascends for some space directly over the artery.
At the groin the anterior crural nerve lies a little to the outer side of the femoral artery (about a quarter of an inch), separated from the vessel by some fibres of the psoas muscle and by fibrous structure. Lower down in the thigh, the long saphenous nerve accompanies the artery until this vessel perforates the adductor magnus. There are likewise small cutaneous nerves which cross the artery.
Peculiarities of the femoral artery
There does not appear to be any well-authenticated example of the femoral artery furnishing the arteries of the leg ; and in this respect the vessels of the lower limb contrast strongly with those of the arm.
Four instances have been recorded of division of the femoral artery, below the origin of the profunda, into two vessels, which subsequently reunited near the opening of the adductor magnus so as to form a single popliteal artery. In all these cases, the arrangement of the vessels appears to have been similar. To one of them (that first observed) special interest is attached, inasmuch as it was met with in a patient operated upon for popliteal aneurism.
From Quain's anatomy.
