Origin and Boundaries
The popliteal artery begins as the direct continuation of the femoral artery. The name changes immediately after the vessel leaves the adductor canal and passes through the adductor hiatus (hiatus adductorius).
The artery terminates at the level of the lower border of the popliteus muscle (m. popliteus). At this anatomical landmark, it bifurcates into its two terminal branches: the anterior and posterior tibial arteries, which travel down into the leg.
Topography in the Popliteal Fossa
Within the popliteal fossa, the vessel has a specific and very deep position. The artery lies deepest among all elements of the neurovascular bundle, resting directly on the popliteal surface of the femur and the capsule of the knee joint. Because of this tight contact with rigid structures, it has minimal mobility.
Considering the structures of the bundle from superficial to deep (from the skin inward), the order is strictly:
- Most superficial is the tibial nerve (n. tibialis).
- Intermediate position is occupied by the popliteal vein (v. poplitea).
- Deepest on the floor of the fossa lies the popliteal artery (a. poplitea).
Main Branches of the Artery
Along its course in the fossa, the artery gives off two types of branches: muscular and articular.
Muscular branches are called sural arteries (aa. surales). These are large vessels that arise approximately at the level of the joint space and supply the bulky muscles of the calf: the gastrocnemius and soleus.
Articular branches are represented by five constant arteries that together form the genicular articular network (rete articulare genus):
- A. superior lateralis genus — loops around the femur above the lateral condyle.
- A. superior medialis genus — passes above the medial condyle.
- A. media genus — the only unpaired branch. It pierces the posterior joint capsule and plays a crucial role: supplying the cruciate ligaments and synovial membrane.
- A. inferior lateralis genus — lies beneath the lateral condyle, directly above the head of the fibula.
- A. inferior medialis genus — lies beneath the medial condyle.
In addition to these five branches, the descending genicular artery (a. descendens genus) and recurrent tibial arteries also contribute to the dense genicular articular network.
Clinical Significance and Injuries
In clinical practice, physicians frequently assess blood flow in this region. The pulse of the popliteal artery can only be palpated when the knee joint is flexed. Flexion is necessary to relax the taut overlying fascia; pulsation is sought deep in the fossa, closer to its lateral margin.
Clinically significant conditions associated with this vessel include:
- Trauma: The artery is rigidly fixed at two points—the adductor hiatus (hiatus adductorius) and the tendinous arch of the soleus muscle (arcus tendineus m. solei). In posterior knee dislocations and supracondylar fractures, the vessel frequently ruptures precisely within this fixed segment.
- Aneurysm: The popliteal artery is the most common site for peripheral aneurysms. The pathology presents as a pulsatile mass in the fossa and carries a high risk of distal embolization into the leg arteries.
- Popliteal Entrapment Syndrome: A specific condition where the artery is compressed by the medial head of the gastrocnemius muscle (frequently seen in young athletes).