Popliteal Fossa and Posterior Leg

Question 1

What is the popliteal fossa?

Answer 1

Space posterior to knee joint

Question 2

What muscles are the boundaries of the popliteal fossa?

Answer 2

Superomedially = semitendinosus and semimembranosus
Superolaterally = biceps femoris
Inferiorly = medial and lateral heads of gastrocnemius

Question 3

How does the small saphenous vein end in the popliteal fossa?

Answer 3

By passing through the deep fascia (popliteal fascia) in the median plane of the limb to drain into the popliteal vein

Question 4

Where is the neurovascular bundle located in the popliteal fossa?

Answer 4

In its median plane

Question 5

What are the contents of the popliteal neurovascular bundle (from superficial to deep)?

Answer 5

Tibial nerve (from sciatic nerve)
Popliteal vein (continuation of posterior tibial vein)
Popliteal artery (continuation of posterior tibial artery)

Question 6

Where are the popliteal lymph nodes located?

Answer 6

Along the popliteal vein in the popliteal fossa

Question 7

Where does the common sciatic nerve most commonly divide into the tibial and common fibular nerves?

Answer 7

The superior apex of the fossa (if not already divided in the gluteal region or posterior thigh)

Question 8

Where does the tibial nerve pass through?

Answer 8

Passes vertically through the fossa

Question 9

Where is the common fibular nerve located?

Answer 9

Skirts the lateral border of the fossa, deep to biceps femoris tendon

Question 10

Where does the common fibular nerve leave the popliteal fossa?

Answer 10

Between the biceps femoris tendon and the lateral head of gastrocnemius to reach the fibular neck

Question 11

What happens to the common fibular nerve once it reaches the fibular neck?

Answer 11

Winds around it before dividing into the deep and superficial fibular nerves

Question 12

Where are the sural nerves located and what do they supply?

Answer 12

Located mainly in superficial fascia of fossa and supply skin and fascia on the posterolateral aspect of the leg and foot

Question 13

What give rise to the sural cutaneous branches?

Answer 13

The tibial nerve = medial sural cutaneous nerve

Common fibular nerve = lateral sural cutaneous nerve

Question 14

How do the sural cutaneous branches communicate?

Answer 14

Via the sural communicating branch

Question 15

What nerves make up the sural nerve?

Answer 15

The medial sural cutaneous nerve and the communicating branch fibres

Question 16

Where does the sural nerve leave the popliteal fossa to supply?

Answer 16

Descends alongside the small saphenous vein in the superficial fascia of the median plane of the posterior compartment of the leg

Question 17

What does the tibial nerve give branches to inside the popliteal fossa?

Answer 17

Both heads of the gastrocnemius, deeper muscles = small plantaris muscle, popliteus muscle

Question 18

Where is the small plantaris muscle located?

Answer 18

Deep to the lateral head of the gastrocnemius (combines inferiorly with the Achilles tendon)

Question 19

Where is the popliteas muscle located?

Answer 19

Deep to plantaris

Question 20

What are two ways the common fibular nerve can be damaged?

Answer 20

Compression injury against neck of fibula, damaged in fractures of the fibular neck

Question 21

What can compression of the common fibular nerve cause?

Answer 21

Dysfunction of the nerve and the muscles it supplies, as well as leading to abnormal sensation in the area of skin supplies by the nerve

Question 22

Why is the popliteal pulse difficult to palpate?

Answer 22

Due to deep location of the popliteal artery and presence of popliteal fat

Question 23

How should the patient’s leg be positioned when palpating the popliteal pulse?

Answer 23

Flex knee to 30 degrees and relax hamstring muscles

Question 24

What are the superficial muscles of the posterior leg?

Answer 24

Gastrocnemius, soleus, plantaris

Question 25

What are the deep muscles of the posterior leg?

Answer 25

Popliteus, flexor hallucis longus, flexor digitorum longus, tibialis posterior

Question 26

What action do the muscles of the posterior leg mostly do?

Answer 26

Flex the ankle and toes

Question 27

What movement does tibialis posterior aid in?

Answer 27

Assists tibialis anterior (anterior of leg) with inversion of foot

Question 28

What nerve supplies the posterior leg?

Answer 28

Tibial nerve = passes through deep to soleus with posterior tibial vessels

Question 29

Where do structures leave the posterior leg?

Answer 29

Reach the sole of the foot by passing posterior to the medial malleolus and deep to the flexor retinaculum

Question 30

What structures leave the posterior leg (from anterior to posterior)?

Answer 30

Tendons of tibialis posterior and flexor digitorum longus, posterior tibial artery, tibial nerve, tendon hallucis longus

Question 31

What are the two heads and muscle bellies of gastrocnemius?

Answer 31

Medial and lateral

Question 32

Where do both heads of gastrocnemius attach?

Answer 32

Distally = calcaneus via Achilles tendon
Proximally = to their respective femoral condyle

Question 33

What actions can gastrocnemius perform?

Answer 33

Crosses both knee and ankle joint so weak knee flexor and powerful ankle plantar-flexor

Question 34

Where does soleus attach proximally?

Answer 34

To neck of fibula and soleal line of tibia (attachment appears to slope inferiorly from lateral to medial)

Question 35

Where does soleus attach distally?

Answer 35

Calcaneus via Achilles tendon

Question 36

Where does soleus get its name from?

Answer 36

It is shaped like a flat fish (a sole)

Question 37

How is the ankle jerk reflex carried out?

Answer 37

Calcaneus tendon struck by tendon hammer just proximal to its insertion into the calcaneus (is deep tendon reflex)

Question 38

What position should the patient be in for an ankle jerk reflex to be performed?

Answer 38

Supine, lower limbs externally rotated, knees flexed and ankle dorsiflexed with gastrocnemius and soleus relaxed

Question 39

What is a normal response to the ankle jerk reflex?

Answer 39

Involuntary contraction of the gastrocnemius and soleus with ankle slightly plantar flexing

Question 40

What does the ankle jerk reflex confirm?

Answer 40

Functions of muscles, their peripheral supply (tibial nerve, S1-2), and the central connections at the spinal cord level and above

Question 41

What are the branches of the popliteal artery present in the popliteal fossa?

Answer 41

Anterior tibial artery, posterior tibial artery, fibular artery

Question 42

Where does the popliteal artery divide into the anterior and posterior tibial artery?

Answer 42

Immediately distal to the popliteal fossa

Question 43

What is the fibular artery a branch of?

Answer 43

Posterior tibial artery

Question 44

Where does the anterior tibial artery supply?

Answer 44

Pierces the interosseous membrane to supply the anterior compartment of the leg

Question 45

Where does the posterior tibial artery supply?

Answer 45

Posterior compartment

Question 46

What does the posterior tibial artery run with?

Answer 46

The tibial nerve, mainly between the superficial and deep muscle

Question 47

Where does the posterior tibial artery leave the posterior compartment of the leg?

Answer 47

Passes posterior to the medial malleolus and deep to the flexor retinaculum

Question 48

Where does the posterior tibial artery terminate?

Answer 48

In the foot by dividing into medial and lateral plantar arteries

Question 49

Where does the fibular artery branch from the posterior tibial artery?

Answer 49

In the proximal half of the posterior compartment of the leg

Question 50

Where does the fibular artery supply?

Answer 50

Descends in compartment on posterior intermuscular septum and sends perforating branches through the septum to supply the lateral compartment of the leg

Question 51

Where are the proximal attachments of the deep muscles of the posterior leg?

Answer 51

All three muscles connect to tibia (inferior to soleal line), mid-shaft of fibula and the interosseous membrane

Question 52

Where do the tendons of the deep muscles of the posterior leg attach?

Answer 52

Pass into sole of foot to attach to medial tarsal bones, distal phalanges of lateral four toes and distal phalanx of great toe