MSK - The Popliteal Fossa

Question 1

What shape is the popliteal fossa and where is it found?

Answer 1

Diamond Shaped

Found on the posterior side of the knee

Question 2

What are the names of the four borders of the popliteal fossa?

Answer 2

Superiomedial Border

Superiolateral Border

Inferiomedial Border

Inferiolateral Border

Question 3

What makes up the superiomedial border of the popliteal fossa?

Answer 3

Semimembranosus

Question 4

What makes up the superiolateral border?

Answer 4

The biceps femoris

Question 5

What makes up the inferiomedial border?

Answer 5

Medial Head of the Gastrocnemius

Question 6

What makes up the inferiolateral border?

Answer 6

Lateral head of the Gastrocnemius and Plantaris

Question 7

What makes up the floor of the popliteal fossa?

Answer 7

Formed by the posterior surface of the knee joint capsule and by the posterior surface of the femur

Question 8

What is the roof of the popliteal fossa made of?

Answer 8

2 Layers

Popliteal Fascia

Skin

Question 9

What are the contents of the popliteal fossa?

Answer 9

A good way of remembering the contents of the popliteal fossa from medial to lateral is by using the mnemonic “Serve And Volley Net Balls”

Semimembranosus (medial border)

Popliteal Artery

Popliteal Vein

Tibial Nerve

Common Fibular Nerve

Biceps Femoris (lateral border)

Question 10

What are the most superficial contents of the popliteal fossa?

Answer 10

Tibial and Common Fibular Nerves

They are both branches of the sciatic nerve

Question 11

What vein empties into the popliteal vein at the popliteal fossa?

Answer 11

The small saphenous vein

Question 12

What is the deepest structure of the popliteal fossa?

Answer 12

The popliteal artery

Question 13

What are the two major causes of an appearance of a mass in the popliteal fossa?

Answer 13

Bakers Cyst

Aneurysm of the popliteal artery

Question 14

What is Bakers Cyst?

How does this usually arise?

What could happen that would cause complications?

Answer 14

Inflammation and swelling of the semimembranosus bursa

Usually arises in conjunction wih arthritis of the knee

Usually selve resolves

Cyst can rupture and produce symptoms similar to deep vein thrombosis.

Question 15

What is an aneurysm?

Why does a popliteal artery aneurysm have consequences for other contents of the popliteal fossa?

Answer 15

A dilation of an artery, which is greater than 50% of the normal diameter

The popliteal fascial layer (the roof of the popliteal fossa) is tough and non extensible

Question 16

What is particularly susceptible to compression from the popliteal artery?

How would this clinically present?

Answer 16

The Tibial Nerve

Leg anethesia or a loss of leg motor function

Question 17

How can an aneurysm of the popliteal artery be detected?

Answer 17

Obvious palpable pulsation in the popliteal fossa with abnormal arterial sounds

Question 18

What are some other causes of a popliteal mass in the popliteal fossa?

Answer 18

Deep Vein Thrombosis

Adventitial Cyst of the Popliteal Artery

Various Neoplasms (such as rhabdomyosarcoma)

Question 19

What is represented by the purple highlighted area?

Answer 19

Semimembranosus

Question 20

What is represented by the area highlighted in green?

Answer 20

Biceps Femoris

Question 21

What is represented by the area highlighted in blue?

Answer 21

Plantaris

Question 22

What is represented by the area highlighted in brown?

Answer 22

Medial head of gastrocnemius

Question 23

What is represented by the area highlighted in orange?

Answer 23

Lateral head of gastrocnemius