Popliteal Fossa and Posterior Leg

popliteal fossa

- this is a diamond-shaped area at the back of the knee/posterior aspect of

the knee

- this area is the major pathway that neurovascular structures take to cross

between the thigh and leg

semimembranosus

superomedial border of the popliteal fossa

biceps femoris

superolateral border of the popliteal fossa

medial head of gastrocnemius

inferomedial border of the popliteal fossa

lateral head of the gastrocnemius and plantaris muscle

inferolateral border of the popliteal fossa

distal metaphysis of the femur

The floor of the popliteal fossa is formed partially by

popliteal artery, popliteal vein, tibial nerve, common peroneal nerve

List the 4 components of the popliteal fossa (medial to lateral)

popliteal artery

- the distal continuation of thefemoral artery

- rests against the distal femoral metaphysis

- site of popliteal aneurysms

popliteal vein

associated with deep vein thrombosis

DVT

- formation of blood clot in the PV

- symptoms include warm leg, pain, & swelling

- if the clot moves into the lungs, it may result in a pulmonary

embolism

tibial nerve

lateral to the popliteal vessels & superficial

common peroneal nerve

most lateral & superficial

baker cyst

- synovial fluid that extrudes from the knee joint capsule, lodging deep to the medial head of the gastrocnemius muscle

- this may result in swelling in the popliteal fossa and loss of full

knee joint mobility

popliteal artery

as soon as the femoral artery appears in the popliteal fossa, it changes its name to

popliteal artery

- blood supply to the knee joint!

- gives off a series of "genicular arteries" that supply the knee joint

middle genicular artery

blood supply to the

anterior cruciate ligament (ACL)

distal border of the popliteus muscle

at the ______ ______ __ ___ ________ ________, the popliteal artery divides into the anterior tibial artery and the posterior tibial artery

popliteal artery aneurysms

- relatively uncommon, but most common in elderly males

- may be entirely asymptomatic but may also present as throbbing

sensation at popliteal fossa

popliteal fossa

Because of its location in the _____ ______, the popliteal artery is endangered in transepicondylar femoral fx, knee joint dislocations

sciatic nerve

this nerve terminates at the popliteal fossa

tibial nerve

- medially located branch of the sciatic nerve and deep

- destined for the posterior compartment of the leg and the foot

tibial nerve

What innervates the following:

- long head, biceps femoris muscle

- semitendinosus muscle

- semimembranosus muscle

- all musculature of the posterior leg & the foot

tibial nerve

supplies sensation to the plantar surface of the foot (by way of the lateral plantar nerve and medial plantar nerve)

common peroneal nerve

- laterally located branch of the sciatic nerve

- winds around the fibular head

- common site of injury because it is so superficial here

common peroneal nerve

this innervates the short head of the biceps femoris muscle

superficial and deep peroneal nerves

after the common peroneal nerve reaches the fibular head, it splits

superficial peroneal nerve

motor to muscles of the lateral compartment of the leg AND sensory to the lateral part of the leg & most of the dorsum of the foot

deep peroneal nerve

motor to muscles of the anterior compartment of

the leg AND sensory to the webspace between the first two toes

posterior compartment of the leg

- these muscles are ankle plantarflexors and digital flexors

- all muscles supplied by tibial n.

- these muscles are divided into a superficial and a deep compartment

posterior bones and bony landmarks

- medial malleolus of tibia

- lateral malleolus of fibula

- calcaneus

- calcaneal tuberosity

- talus

- navicular

triceps surae

union of gastrocnemius (two heads) and soleus mm

plantarflexes ankle, medial head stabilizes knee

function of the gastrocnemius

calcaneal tuberosity via the calcaneal tendon

what is the insertion of the gastrocnemius?

tibial nerve

What innervates the gastrocnemius?

plantarflexes ankle, active in normal upright posture

What is the function of the soleus?

calcaneal tuberosity via the calcaneal tendon

what is the insertion of the soleus?

tibial nerve

What innervates the soleus?

achilles tendon rupture

- IMMEDIATE and long-lasting pain

- sudden, forced plantarflexion followed by rapid deceleration, fast pivoting

- accompanied by a loud "pop" and inability to bear weight on that limb, along with a visible "lump" in the mid-region of the posterior leg

weak plantarflexion

What is the function of the plantaris?

calcaneal tubersoity

What is the insertion of the plantaris?

tibial nerve

What is the innervation of the plantaris?

plantaris tendon rupture

- IMMEDIATE pain that immediately disappears

deep posterior compartment

- popliteus

- flexor hallicus

- tibialis posterior

- flexor digitorum

flexes and rotates knee

What is the function of the popliteus?

popliteal line of tibia

What is the insertion of the popliteus?

tibial nerve

What is the innervation of the popliteus?

flexor hallicus longus, tibialis posterior, flexor digitorum

List the muscles that cross the ankle from lateral to medial

flexes 1st digit

What is the function of the flexor hallicus longus?

plantar surface of distal phalanx of 1st digit

What is the insertion of the flexor hallicus longus?

tibial nerve

What is the innervation of the flexor hallicus longus?

inverts ankle

What is the function of the tibialis posterior?

navicular and bases of 2nd-4th metatarsals

What is the insertion of the tibialis posterior?

tibial nerve

What is the innervation of the tibialis posterior?

flexes digits 2-5

What is the function of the flexor digitorum longus?

distal phalanges of 2nd-5th digits

What is the insertion of the flexor digitorum longus?

tibial nerve

What is the innervation of the flexor digitorum longus?

tibialis posterior, flexor digitorum longus, flexor hallicus longus

Order the tendons from anterior to posterior after they flip at the medial malleolus

flexor retinaculum

- DENSE connective tissue roof that stretches across the medial malleolus of the tibia and the medial side of the calcaneus

- binds the TP, FDL, and FHL tendons

- binds the posterior tibial artery & tibial nerve

- the flexor retinaculum turns this area into a "tunnel" with a connective tissue roof

compartments of tarsal tunnel

- 1st compartment: tendon of TP & its synovial sheath

- 2nd compartment: tendon of FDL & its synovial sheath

- 3rd compartment: posterior tibial artery & tibial nerve

- 4th compartment: tendon of FHL & its synovial sheath

tarsal tunnel syndrome

- pain radiating through the plantar surface of the foot

- the synovial sheaths surrounding "Tom, Dick, & Harry" may become inflamed with overuse

- this inflammation may compress the tibial nerve within the tarsal tunnel

and cause radiating pain throughout the foot

- WORSE yet, it may compress the PTA and produce intermittent

claudication of blood supply to the foot

- this claudication would diminish the pulse of the PTA

anterior tibial artery and posterior tibial artery

at the distal border of the popliteus m., popliteal artery splits into the:

- accompanied by deep peroneal n. and enters the anterior leg

- branches to anterior leg mm., knee, and ankle joints

dorsalis pedia

- once the anterior tibial artery crosses onto the dorsum of the foot,

it changes its name to the

posterior tibial artery

- PULSE PALPATION

- accompanied by tibial n. in the posterior leg

peroneal artery

- posterior tibial artery gives off the ______ ______ to the lateral

muscles of the leg

lateral and medial plantar artery

- within the tarsal tunnel, the PTA splits into the ______ ______ ______ and the _____ _____ _______, which each make their way to the plantar surface of the foo

tibial nerve

- medial branch of sciatic n., given off at popliteal fossa

- passes through the popliteal fossa with popliteal a.

- enters posterior leg with posterior tibial a

tibial nerve

- enters the tarsal tunnel with the PTA in the 3rd compartment

- Sensory to: plantar surface of the foot, by way of the medial & lateral plantar nerves)

common peroneal nerve

- lateral branch of sciatic n., given off in popliteal fossa

- motor to the short head of the biceps femoris m.

superficial and deep peroneal nerve

at the fibular neck, the common peroneal nerve divides into

___________ that go to the anterolateral leg

deep peroneal nerve

motor to the:

- tibialis anterior m.

- extensor hallucis longus m.

- extensor digitorum longus

- peroneus tertius m

deep peroneal nerve

sensory to the skin in the webspace between the first two toes