Arteries of the Lower Limb
The arterial supply to the lower limb is chiefly supplied by the femoral artery and its branches.
In the Thigh and Gluteal Region
Femoral Artery
-The main artery of the lower limb is the femoral artery. It is a continuation of the external iliac artery
(terminal branch of the abdominal aorta). The external iliac becomes the femoral artery when it crosses under
the inguinal ligament and enters the femoral triangle.
-In the femoral triangle, the profunda femoris artery arises from the posterolateral aspect of the femoral artery.
It travels posteriorly and distally, giving off three main branches:
● Perforating branches – Consists of three or
four arteries that perforate the adductor
magnus, contributing to the supply of the
muscles in the medial and posterior thigh.
● Lateral femoral circumflex artery – Wraps
round the anterolateral aspect of the femur,
supplying muscles on the lateral aspect of
the thigh.
● Medial femoral circumflex artery – Wraps
round the posteromedial aspect of the
femur, supplying its neck and head. In a
fracture of the femoral neck this artery can
easily be damaged, and avascular necrosis of
the femur head can occur.
-After exiting the femoral triangle, the femoral artery continues down the anterior aspect of the thigh, through a
tunnel known as the adductor canal. During its descent, the artery supplies the anterior thigh muscles.
-The adductor canal ends at an opening in the adductor magnus, called the adductor hiatus. The femoral artery
moves through this opening, and enters the posterior compartment of the thigh, proximal to the knee. The
femoral artery is now known as the popliteal artery.
-Clinical Relevance (Accessing the Femoral Artery)
-The femoral artery is located superficially within the femoral triangle, and is thus easy to access. This makes it
suitable for a range of clinical procedures.
-One such procedure is coronary angiography. Here, the femoral artery is catheterised with a long, thin tube.
This tube is navigated up through the external iliac artery, common iliac artery, aorta, and into the coronary
vessels. A radio-opaque dye is then injected into the coronary vessels, and any wall thickening or blockages can
be visualised via x-ray.
Other Arteries of the Thigh
-In addition to the femoral artery, there are other vessels supplying the lower limb.
-The obturator artery arises from the internal iliac artery in the pelvic region. It descends via the obturator
canal to enter the medial thigh, bifurcating into two branches:
● Anterior branch – This supplies the
pectineus, obturator externus, adductor
muscles and gracilis.
● Posterior branch – This supplies some
of the deep gluteal muscles.
-The gluteal region is largely supplied by
the superior and inferior gluteal arteries.
These arteries also arise from the internal
iliac artery, entering the gluteal region via
the greater sciatic foramen.
-The superior gluteal artery leaves the
foramen above the piriformis muscle, the
inferior below the muscle. In addition to the
gluteal muscles, the inferior gluteal artery
also contributes towards the vasculature of
the posterior thigh.
In the Leg
-The popliteal artery descends down the posterior thigh, giving rise to genicular branches that supply the knee
joint. It moves through the popliteal fossa, exiting between the gastrocnemius and popliteus muscles.
-At the lower border of the popliteus, the popliteal artery terminates by dividing into the anterior tibial artery
and the tibioperoneal trunk. In turn, the tibioperoneal trunk bifurcates into the posterior tibial and fibular
arteries:
● Posterior tibial artery – continues inferiorly, along the surface of the deep posterior leg muscles (such as
tibialis posterior). It enters the sole of the foot via the tarsal tunnel, accompanying the tibial nerve.
● Fibular (peroneal) artery – descends posteriorly to the fibula, within the posterior compartment of the leg. It
gives rise to perforating branches, which penetrate the intermuscular septum to supply muscles in the lateral
compartment of the leg.
-The other division of the popliteal artery, the anterior tibial artery, passes anteriorly between the tibia and
fibula, through a gap in the interosseous membrane. It then moves inferiorly down the leg. It runs down the
entire length of the leg, and into the foot, where it becomes the dorsalis pedis artery.
Clinical Relevance
(Popliteal Aneurysm)
-An aneurysm is a dilation of an artery, which is greater than 50% of the normal diameter. The popliteal fascia
(the roof of the popliteal fossa) is tough and non-extensible, and so an aneurysm of the popliteal artery has
consequences for the other contents of the popliteal fossa.
-The tibial nerve is particularly susceptible to compression from the popliteal artery. The major features of tibial
nerve compression are:
● Weakened or absent plantarflexion
● Paraesthesia of the foot and posterolateral leg
-An aneurysm of the popliteal artery can be detected by an obvious palpable pulsation in the popliteal fossa. An
arterial bruit may be heard on auscultation.
In the Foot
-Arterial supply to the foot is delivered via two arteries:
● Dorsalis pedis (a continuation of the anterior tibial artery)
● Posterior tibial
-The dorsalis pedis artery begins as the anterior tibial artery enters the foot. It passes over the dorsal aspect of
the tarsal bones, then moves inferiorly, towards the sole of the foot. It then anastomoses with the lateral plantar
artery to form the deep plantar arch. The dorsalis pedis artery supplies the tarsal bones and the dorsal aspect of
the metatarsals. Via the deep plantar arch, it also contributes to the supply of the toes.
-The posterior tibial artery enters the sole of the foot through the tarsal tunnel. It then splits into the lateral and
medial plantar arteries. These arteries supply the plantar side of the foot, and contribute to the supply of the
toes via the deep plantar arch.
Clinical Relevance
Pulse Points in the Lower Limb
There are four main pulse points in the lower limb; femoral, popliteal, posterior tibial and dorsalis pedis.
● The femoral pulse can be palpated as it enters the femoral triangle, midway between the anterior superior
iliac spine of the pelvis, and the pubis symphysis (the mid-inguinal point).
● The popliteal artery is the hardest pulse to find. It lies deep in the popliteal fossa, and requires deep palpation
to feel. To make it easier, you can ask the patient to slightly flex their leg – this relaxes the fascia around the
popliteal fossa.
● The dorsalis pedis pulse is found by palpating on the dorsum of the foot, just lateral to extensor hallucis
longus tendon.
● The posterior tibial pulse can be palpated inferoposteriorly to the medial malleolus, where the artery turns to
enter the foot.
