The popliteal fossa is a diamond shaped area located on the posterior aspect of the knee. It is the main path by which vessels and nerves pass between the thigh and the leg.
In this article, we shall look at the anatomy of the popliteal fossa – its borders, contents and clinical correlations.
Borders
The popliteal fossa is diamond shaped with four borders. These borders are formed by the muscles in the posterior compartment of the leg and thigh:
- Superomedial border – semimembranosus.
- Superolateral border – biceps femoris.
- Inferomedial border – medial head of the gastrocnemius.
- Inferolateral border – lateral head of the gastrocnemius and plantaris.
The floor of the popliteal fossa is formed by the posterior surface of the knee joint capsule, popliteus muscle and posterior femur. The roof is made of up two layers: popliteal fascia and skin. The popliteal fascia is continuous with the fascia lata of the leg.
By TeachMeSeries Ltd (2023)
Fig 1 – The borders of the popliteal fossa are formed by the muscles of the thigh and leg.
Contents
The popliteal fossa is the main conduit for neurovascular structures entering and leaving the leg. Its contents are (medial to lateral):
- Popliteal artery
- Popliteal vein
- Tibial nerve
- Common fibular nerve (common peroneal nerve)
The tibial and common fibular nerves are the most superficial of the contents of the popliteal fossa. They are both branches of the sciatic nerve. The common fibular nerve follows the biceps femoris tendon, travelling along the lateral margin of the popliteal fossa.
The small saphenous vein pierces the popliteal fascia and passes between the two heads of gastrocnemius to empty into the popliteal vein.
In the popliteal fossa, the deepest structure is the popliteal artery. It is a continuation of the femoral artery, and travels into the leg to supply it with blood.