B6.047 Popliteal Fossa, Leg, Foot Flashcards
roof of popliteal fossa
crural fascia
why is there so much fatty packing material in the popliteal fossa?
to prevent strangulation of the vessels and nerves when assuming a crouched or squatting position
crural fascia
deep, investing layer of the leg
continuous with fascia lata
floor of popliteal fossa
capsule of knee joint, bone, and popliteus muscle
major artery in popliteal fossa
femoral artery descends into fossa, and emerges as the popliteal artery
course of neurovascular bundle in popliteal fossa
passes from the thigh to the leg by traveling deep in the fossa
structures are posterior to popliteus muscle and pass anterior to (under) the tendinous arch of the soleus
contents of neurovascular bundle in popliteal fossa
popliteal artery (most anterior, deepest)
popliteal vein
tibial nerve
vein junction in fossa
small saphenous joins popliteal vein within fossa
sural nerve
formed from twigs of the tibial and common fibular
cutaneous nerve of the calf, lateral ankle, and foot
origin of tibial and common fibular nerves
branches of the sciatic
often split within the popliteal fossa
pulse pressure in the popliteal fossa
importance in EM and evaluation of peripheral vascular disease
particularly if no pulse detected in foot
swollen popliteal lymph nodes
requires examination of distal structures for evidence of inflammation or disease
popliteal hemorrhage
risk associated with fractures of the distal femur and severe knee injury
on rare occasions, arterial to venous popliteal fistula can form that severely compromises blood flow
can lead to leg amputation if not identified promptly
what makes up “compartments” in the leg
tough, robust fascial framework
interosseous membrane
binds tibia and fibula together
site of attachment of some muscles
helps to decrease energy output of standing
great saphenous vein
arises on medial foot
ascends to the thigh and empties into saphenous opening
nerve associated with great saphenous vein
saphenous nerve (branch of femoral nerve) cutaneous nerve
small saphenous vein
arises in the skin of the dorsal, lateral, and plantar foot
ascends the leg and typically empties into the popliteal fossa
fascial compartments in the leg
anterior
lateral
posterior (superficial and deep)
tendons of anterior leg muscles
all pass anterior to ankle joint
tendons of lateral leg muscles
all pass lateral to the ankle joint
tendons of “superficial” posterior compartment
all pass posterior to the ankle joint
tendons of “deep” posterior compartment
all pass medial to the ankle joint
muscles of the anterior compartment
tibialis anterior extensor hallicus longus extensor digitorum longus fibularis tertius (half of the population)
function of anterior muscles
dorsiflexion of foot at ankle
prevent toe stubbing
help smooth gait
innervation of anterior compartment
deep branch of the common fibular nerve
danger associated with common fibular nerve
lies close to the surface
susceptible to injury
loss of this nerve leads to pathological foot drop gait
lateral muscles
fibularis longus
fibularis brevis
innervation of lateral muscles
superficial branch of common fibular nerve
function of lateral muscles
evertors
critical to precise positioning of the foot on the ground and to maintain balance when walking or standing on uneven terrain
posterior superficial muscles
gastrocnemius
soleus
function of posterior superficial muscles
flex foot at the ankle joint
resist gravity and propel body forward during gait
innervation of posterior superficial muscles
tibial nerve
posterior deep muscles
tibialis posterior
flexor digitorum longus
flexor hallicus longus
damage of tibialis posterior
surrounded on 3 sides by rigid structures
swelling and bleeding causes significant complications
hypertrophy of muscle leads to high compartmental pressure injury to motor nerves and occlusion of arteries
orientation of tendons, nerve, and vessels at the flexor retinaculum
all deep to flexor retinaculum, posterior to medial epidcondyle
moving from epicondyle posterior and deep:
1. tibialis posterior
2. flexor digitorum
3. post. tibial artery and tibial nerve
4. flexor hallicus longus
tom, dick, and bloody nervous, harry
branches of popliteal artery
anterior tibial artery (pierces to anterior side distal to the knee joint)
posterior tibial artery
-fibular artery
arteries of the knee
genicular arteries
gastrocnemius blood supply and innervation
sural arteries and tibial nerve branches
sural arteries are end arteries with no collateral tributaries
2 major arteries of posterior leg
posterior tibial artery (goes down to flexor retinaculum)
fibular artery
vary widely in diameter
varicosities
common in superficial leg veins
caused by incompetent valves
Osgood Schlatter disease
exceptional exertion of quadriceps muscles by young or adolescent athletes can place undue strain on the tibial tuberosity
can cause extreme pain and swelling
can also damage epiphysial growth plate situated near the tibial tuberosity, causing growth fialure
housemaid/ surfers knee
form of bursitis, inflammation of the superficial, and subcutaneous infrapatellar bursae
results from excessive pressure and friction on the patella/tibial tuberosity caused by patient spending extended periods of time on knees
bursitis of the calcaneal tendon
common complaint of long distance runners
ruptured calcaneal tendon
severe, acute injury
affected foot cannot be flexed at the ankle against gravity (other posterior leg muscles aren’t sufficiently powerful)
walking only possible by exaggerated external rotation of the hip and passively swinging the lower limb forward by hip and spine rotation
what allows leg muscle tendons to change the direction of pulling force at the ankle
retinacula
- superior extensor retinaculum
- inferior extensor retinaculum
- fibular retinacula
- flexor retinaculum
flexor retinaculum
constrains the deep flexor tendons at the medial ankle
superior extensor retinaculum
contains extensor muscle tendons (anterior leg group_
plantar aponeurosis
flat ligament on sole that arises on calcaneous and extends to metatarsals
deep investing layer that forms a tough connective tissue boundary
wear is the majority of weight bearing
sesamoid bones of 1st and 2nd metatarsal
50% of weight bearing
skeletal components of the dorsal foot
10 phalanges 5 metatarsals 5 tarsals (3 cuneiforms, 1 navicular, 1 cuboid) talus calcaneous
sustentaculum tali
shelf of bone on calcaneous that supports Talus
is the head of talus supported by bone?
no
hangs over
supported by spring ligament: plantar calcaneonavicular ligament
planter fasciae components
- significant superficial fatty tissue, which cushions the foot
- plantar aponeurosis (connective tissue)
muscles of the plantar foot
4 musculo-tendinous tissue layers
sensors of proprioception
major arteries of the plantar foot
posterior tibial artery
- lateral plantar artery
- medial plantar artery
- —plantar arch
plantar innervation
arise from tibial nerve
lateral plantar nerve
medial plantar nerve
innervate all plantar muscles
muscles of dorsal foot
extensor digitorum brevis
extensor hallicus brevis
innervation of dorsal foot
deep fibular nerve
major arteries of the dorsal foot
anterior tibial artery
- dorsal artery of the foot
- arcuate artery
anastomoses of arteries in foot
perforating branch from the plantar arch goes up to the dorsal arch
cutaneous innervation of the foot
saphenous = medial malleolus and medial arch
superficial fibular = lateral ankle and dorsal foot except inner half of big toe and 2nd toe
deep fibular nerve = inner half of big toe and 2nd toe
dorsal lateral cutaneous nerve of foot = lateral foot and a bit of plantar surface
medial plantar nerve = medial 3.5 toes and arch
lateral plantar nerve = lateral 1.5 toes and arch
medial calcaneal branch = heel
ligaments of medial longitudinal arch
passive support -plantar aponeurosis -short plantar ligament -long plantar ligament -plantar calcaneonavicular ligament (spring) dynamic support -tibialis posterior -tibialis anterior -flexor hallicus longus -fibularis longus -intrinsic plantar muscles
function of talus
sits at the top of a bony arch
participates in 3 joints: ankle, sub talar, transverse talar
flat foot etiology
collapse of medial longitudinal arch
due to dysfunction of the tibialis posterior
structure that maintains the arch
spring ligament
collapse of this structure allows the head of the talus to fall and push aside the calcaneous and navicular bones
what causes arch failure
duration of stress > severity of stress
professors»_space; athletes
plantar fasciitis
continuous overloading stress of the plantar fascia by running and jumping
leads to inflammation, pain, and swelling where the ligament attaches to the bone (calcaneous)
dorsal artery pulse
important for evaluating peripheral vessel health
evaluated in diabetics particularly
