popliteal fossa and leg Flashcards
where is the superficial fascia?
deep to skin and superficial to the crural fascia
what are the 2 major superficial veins?
great and small saphenous
what gives rise to the great saphenous vein?
the union of the dorsal vein of the great toe and the dorsal venous arch
what does the great saphenous vein empty into?
the femoral vein
where does the great saphenous vein run?
medial aspect of the leg and thigh
what does the small saphenous vein arise from?
the lateral side of the foot where the dorsal vein of the small toe meets the dorsal venous arch
what does the small saphenous vein empty into?
the popliteal vein after coursing along the posterior aspect of the leg
deep fascial extensions divide the leg into what 3 compartments?
anterior, lateral, and posterior
why is the great saphenous vein commonly used for coronary arterial bypasses?
it is readily accessible
usable lengths can be harvested
its walls contain a higher percentage of muscular and elastic fibers than other superficial veins
(when grafted the direction is reversed because of valves)
the leg contains what bones?
tibia and fibula
which bone is non weight bearing?
fibula
describe a tibial fibular fracture
tibia= junction of middle and inferior thirds- - compound fracture because of subcutaneous location, the fibula commonly fractures a few cm above the distal end- more complicated when the tibiofibular syndesmosis is torn- common with traumatic inversion injury
what is the anterior compartment also known as?
the dorsiflexor (Extensor) compartment
what bounds the anterior compartment?
the lateral surface of the tibia, the interosseous membrane, the medial surfaces of the fibula, and the anterior intermuscular septum. inferiorly, 2 fascial thickenings the superior and inferior extensor retancula hold the long tendons in place as they course through the foot
which is the largest compartment of the leg?
posterior
what divides the posterior compartment into superficial and deep?
the transverse intermuscular septum
what does the flexor retinaculum represent?
a continuation of the transverse intermuscular septum as it spans from the medial malleolus to the calcaneus. holds tendons as well as the tibial nerve, and posterior tibial artery
what is the lateral compartment also known as?
the evertor compartment
where does the lateral compartment end?
at the superior fibular retinaculum
what is the popliteal fossa?
a mostly fat filled space of the lower extremity
what muscle or muscles cover the deep inferior part of the popliteal fossa?
the heads of the gastrocnemius muscle… this makes the popliteal fossa appear smaller than it actually is
what is the superolateal boundary of the popliteal fossa?
biceps femoris muscle
what is the superomedial boundary of the popliteal fossa?
semimebranosus and semitendinosus muscle
what is the inferolateal boundary of the popliteal fossa?
lateral head of the gastrocnemius muscle
what is the inferomedial boundary of the popliteal fossa?
medial head of the gastrocnemius muscle
what is the roof of the popliteal fossa?
skin and deep fascia
what are the deep superior borders of the popliteal fossa?
supracondylar lines of the femur
what is the deep inferior border of the popliteal fossa?
soleal line of tibia
what is the floor of the popliteal fossa?
the posterior capsule of the knee and the fascia covering the popliteus muscle
what are the contents of the popliteal fossa?
termination of the small saphenous vein
popliteal artery and vein
tibial and common fibular nerves
posterior cutaneous nerve of the thigh
lymph nodes and vessels
fat
what are popliteal (bakers) cysts a result from?
chronic knee joint effusion, synovial lined extension of joint space containing fluid pushes through posterior joint capsule. may enlarge to cause pain and lack of motion
what happens when the femoral artery passes through the adductor hiatus?
it becomes the popliteal artery
what does the popliteal artery give rise to?
5 genicular arteries, an anastamosis for the knee joint and anterior and posterior tibial arteries
where does the popliteal artery divide into the anterior and posterior tibial arteries?
at the inferior border of the popliteus muscle
what is the fibular artery a branch of?
the posterior tibial artery
what is the artery of the anterior compartment?
anterior tibial artery
when does the anterior tibial artery become the dorsal artery of the foot (dorsalis pedis)
distal to the inferior extensor retinaculum
what is the artery of the posterior compartment?
the posterior tibial artery- it is a more direct continuation of the popliteal artery
when does the posterior tibial artery divide and into what?
distal to the flexor retinaculum and into the medial and lateral plantar arteries
where does the fibular artery run?
lateral and parallel to the posterior tibial artery supplying the lateral compartment
why do we need an anastomosis in the knee?
because full knee flexion could kink the popliteal artery since it is deepest in the popliteal fossa directly against the posterior aspect of the knee capsule. ansastomic channels are important to maintain arterial flow to surrounding structures
what are the 5 geniculate arteries?
superior lateral
superior medial
inferior lateral
inferior medial
middle
what contributes to the anastomosis in the knee?
the 5 geniculate arteries, branches of the femoral and lateral circumflex arteries, the anterior recurrent artery and posterior recurrent artery
where does the sciatic nerve divide and into what?
at the superior margin of the popliteal fossa into the tibial and common fibular nerve
what does the tibial nerve do?
bisect the fossa and gives branches to the superficial posterior muscles and popliteus
what makes up the sural nerve?
the medial and lateral cutaneous sural nerves
medial from tibial nerve lateral from the fibular nerve
what does the sural nerve innervate?
the skin on the lateral side of the leg and ankle
what does the tibial nerve bifurcate into?
the medial and lateral plantar nerve distal to flexor retinaculum
what does the common fibular nerve follow?
the medial border of the biceps femoris muscle and leaves the popliteal fossa by passing superficial to the lateral head of the gastrocnemius muscle and posterior to the fibular head
when does the common fibular nerve divide and into what?
after it winds around the fibular head and into the superficial and deep fibular nerves
what does the superficial fibular nerve do?
supplies the muscles of the lateral compartment and skin on the distal third of the anterior surface of the leg and the majority of the dorsum of the foot
what does the deep fibular nerve do?
descends on the surface of the interossesous membrane and supplies the anterior muscles of the leg and dorsum of foot and small area of skin between the 1st and 2nd toes
what muscles make up the anterior compartment of the leg and what do they do?
tibialis anterior
extensor digitorum longus
extensor hallucis longus
fibularis tertius
dorsiflex the ankle joint
what is tibialis anterior strain (“shin spints”)?
due to microtrauma of the tibialis anterior muscle and small tears in the periosteum. overextension causes edema/swelling and pain- mild form of compartment syndrome
which is the strongest ankle dorsiflexor?
tibialis anterior
what are the muscles in the lateral compartment and what do they do?
fibularis brevis
fibularis longus
evert the ankle
what is a common fibular nerve injury?
when injured due to its vulnerable superficial position theres a loss of dorsiflexion causes a characteristic foot drop
what muscles make up the superficial posterior compartment and what do they do?
gastrocnemius, soleus, plantaris
plantarflex the ankle
what is the thickest and strongest tendon in the body?
(achilles) calcanael tendon
what does the term triceps surae refer to?
the 3 headed muscle of the calf made up of the soleus and both heads of the gastrocnemius
described a ruptured calcaneal tendon
rare but severe injury. the tendon tears when the knee is flexed with a sudden push off the platarflexed foot. an audible snap and immediate pain results. with a complete tear a gap results just superior to the calcaneus. ambulation is severely compromised but possible with ER of limb
which nerve root is the calcaneal tendon reflex?
mostly S1
what are the muscles of the deep posterior compartment and what do they do?
tibialis posterior, flexor digitorum longus, flexor hallucis longus, and popliteus. all but popliteus plamtarflex the ankle
