The Popliteal Fossa

Question 1

State the boundaries of the popliteal fossa.

Answer 1

Superomedial: Semimembranosus, semitendinosus
Superolateral: Biceps femoris
Inferomedial: Medial head of gastrocnemius
Inferolateral: Lateral head of gastrocnemius
Roof: Skin and popliteal fascia
Floor: Popliteal surface of the femur, popliteal capsule of the knee joint (reinforced by the oblique popliteal ligament, and popliteus muscle and the fascia covering it).

NOTE: The popliteal fascia is the posterior inferior aspect of the fascia lata over the popliteal fossa.

[Diagram] [Cadaveric image]

Question 2

What structures are found on the roof of the popliteal fossa, on the popliteal fascia?

Answer 2

a) Termination of the small saphenous vein
b) Terminal branches of the posterior cutaneous nerve of the thigh
c) Sural nerve

Question 3

State the contents of the popliteal fossa.

Answer 3

Popliteal artery and its branches
Popliteal vein and its tributaries
Tibial and common peroneal nerves.
Termination of the small saphenous vein.
Lower part of the posterior cutaneous nerve of the thigh.
Popliteal lymph nodes, connective tissue and fat.

Question 4

Name 4 branches of the common peroneal nerve, given in the popliteal fossa.

Answer 4

• lateral cutaneous nerve of the calf
• sural communicating nerve/ lateral sural
• deep peroneal nerve (terminal branch)
• superficial peroneal nerve (terminal branch)

[NB: The superior lateral genicular nerve is a branch of the nerve to vastus lateralis.]

Question 5

Name the branches of the tibial nerve given off in the popliteal fossa

Answer 5

• sural nerve/ medial sural
• superior medial genicular
• middle genicular
• inferior medial genicular

Question 6

State the extents, relations, branches, variations and clinical relevance of the popliteal artery.

Answer 6

EXTENTS:
Adductor hiatus to lower part of popliteus/soleal arch

RELATIONS:
Anteriorly:
Popliteal surface of femur
Capsule of knee joint
Popliteus muscle/fascia

Posteriorly:
Popliteal vein
Tibial vein

BRANCHES:
Genicular branches i.e.superior medial and lateral, inferior medial and lateral, and middle genicular (this one anchors the pop. artery to the knee making it vulnerable to injury in cases of knee dislocation)
Muscular branches
Anterior tibial artery
Posterior tibial artery

VARIATIONS:
~ early bifurcation (above level of popliteus)
~ division into ant. tibial and peroneal arteries with rudimentary post. tibial
~ trifurcation into ant. tibial, post. tibial, and peroneal

CLINICAL RELEVANCE:
~ Occlusion leads to gangrene (tissue loss) in the leg
~ Injured in supracondylar fracture
~ Partial narrowing leads to intermittent claudication (pain in the legs or arms that occurs while walking or using the arms).
~ Aneurysms (bulge in arterial wall)

Question 7

The nerve to popliteus is a branch of ____(1)____. It supplies 6 structures namely: ____(2)____.

Answer 7

1. tibial nerve
2. • tibialis posterior muscle
   • superior tibiofibular joint
   • inferior tibiofibular joint
   • interosseus membrane
   • tibia

Question 8

Name the four neurovascular structures piercing the roof of the popliteal fossa.

Answer 8

From medial to lateral:
(a) posterior division of the medial cutaneous nerve of the thigh
(b) the posterior cutaneous nerve of the thigh
(c) the short saphenous vein
(d) the sural communicating nerve
[Diagram]

Question 9

What is Baker’s cyst?

Answer 9

This is a cystic swelling which occurs in the popliteal fossa due to inflammation of the synovial bursa underneath the tendon of semimembranosus or protrusion of synovial membrane of the cavity of knee joint through the fibrous capsule of the joint. [Diagram]

Question 10

[5-minute video]: the Popliteal artery

Answer 10

🙂