Popliteal fossa

Introduction:

• Popliteal fossa is a shallow diamond shaped fossa at the back of the knee.
• This corresponds to the triangular shaped Cubital fossa in the forearm.
• Most importantly it is felt best during the Semi-flexed position of the knee joint.

Location:

• It is a diamond-shaped depression located behind the knee joint.
• Moreover behind the lower part of the Femur and upper part of the Tibia.

Boundaries of Popliteal Fossa:

Superolaterally :

• Biceps femoris.

Superomedially:

• Semitendinosus and the Semimembranosus.

Moreover Gracilis, Sartorius and Adductor magnus supplements the superomedial boundary.

Inferolaterally :

• Lateral head of Gastrocnemius.

Moreover Planatris also bounds the fossa inferolaterally.

Inferomedially:

• Medial head of Gastrocnemius.

Roof:

Roof of the fossa is formed by Deep Fascia/Popliteal fossa.

The superficial fascia over the roof contains the following structures.They are:-

• Small saphenous vein and cutaneous nerves.
• Three cutaneous nerves.They are,
  • Firstly Terminal part of posterior cutaneous nerve of thigh
  • Secondly Posterior division of the medial cutaneous nerve of thigh.
  • Finally the Peroneal or sural communicating nerve.

Floor:

From above downwards,

• Firstly, Popliteal surface of Femur.
• Secondly, Capsule of the Knee joint and the oblique popliteal ligament.
• Finally, Popliteal fascia covering the Popliteus.

Contents of the Popliteal fossa:

• Firstly- Popliteal artery, Popliteal veins and their branches and tributaries respectively.
• Secondly-Tibial nerve and its branches.
• Most importanly, Common peroneal nerve and its branches.
• The posterior cutaneous nerve of thigh.
• Genicular branch of the Obturator nerve.
• The Popliteal lymph nodes.
• Finally-Fat.
• The popliteal vessels and the tibial nerve are arranged one over the other.
• Structures arranged from deep to superficial are

• Firstly, Popliteal .
• Secondly, Popliteal vein.
• Finally, Tibial nerve.

Relations of the structures in the Popliteal fossa:

Upper part:

From medial to lateral side: Artery, Vein, Nerve.

Middle part:

From behind forwards: Nerve, Vein, and Artery.

Lower part:

From medial to lateral side: Nerve, Vein and Artery.