Page 261 - Clinical Anatomy

ECA4 7/18/06 6:47 PM Page 246

246 The lower limb

Popliteal artery
The popliteal artery continues on from the femoral artery at the adductor
hiatus and terminates at the lower border of the popliteus muscle. It lies
deep within the popliteal fossa (see above), being covered superficially by
the popliteal vein and, more superficially still, crossed by the tibial nerve.
The popliteal artery gives off muscular branches, geniculate branches
(to the knee joint) and terminal branches, the anterior and posterior tibial
arteries.

Clinical features

1◊◊Aneurysm of the popliteal artery, once common, is now rare. Its
frequency in former days was associated with the repeated traumata of
horse-riding and the wearing of high riding-boots.
Pressure of the aneurysm on the adjacent vein may cause venous
thrombosis and peripheral oedema; pressure on the tibial nerve may cause
severe pain in the leg.
2◊◊The popliteal artery is exposed by deep dissection in the midline within
the popliteal fossa, care being taken not to injure the more superficial vein
and nerve. It can also be exposed by a medial approach, which divides the
insertion of adductor magnus and detaches the origin of the medial head of
gastrocnemius from the tibia.

Posterior tibial artery

The posterior tibial artery is the larger of the terminal branches of the
popliteal artery. It descends deep to soleus, where it can be exposed by split-
ting gastrocnemius and soleus in the midline, then becomes superficial in
the lower third of the leg and passes behind the medial malleolus between
the tendons of flexor digitorum longus and flexor hallucis longus. It is
accompanied by its corresponding vein and by the tibial nerve (Fig. 179).
Below the ankle, the posterior tibial artery divides into the medial and
lateral plantar arteries which constitute the principal blood supply to the
foot.
As well as branches to muscles and skin and a large nutrient branch to
the tibia, the posterior tibial artery gives off the peroneal artery about 1.5in
(4cm) from it origin. The peroneal artery runs down the posterior aspect of
the fibula, close to the medial margin of the bone, supplying adjacent
muscles and giving a nutrient branch to the fibula. Above the ankle it gives
off its perforating branch which pierces the interosseous membrane,
descends over the lateral malleolus and anastomoses with the arteries of
the dorsum of the foot.

Anterior tibial artery

The anterior tibial artery arises at the bifurcation of the popliteal artery. It