Vasculature of lower limb Flashcards
What artery is the superior and inferior gluteal artery a branch of?
Internal iliac artery
What does the internal iliac artery branch into?
The superior and inferior gluteal arteries
What is the positioning of the superior and inferior gluteal arteries?
Superior and inferior to pisiform
What is the common femoral arter a continuation of?
The external iliac artery
Why is it crucial that there is anastomosis between branches of internal iliac and profunda femoris arteries
Clinically important – allows blood to bypass a blockage of the external iliac or proximal femoral arteries
What are the 3 arteries of the thigh?
Femoral artery
Profunda femoris artery
Obturator artery
What artery supplies the anterior compartment of the thigh?
Femoral artery
Continuation of external iliac
Boundary - inguinal ligament
What artery supplies the posteiror compartment of the thigh?
Perforating arteries (4)
Which is a branch of the profunda femoris artery
What artery supplies the medial compartment of the thigh?
Obturator artery
A branch of the internal iliac
When does the external iliac artery become the femoral artery?
As the external iliac artery crossess under the inguinal ligament and enteres the femoral triangle
What are the three branches of the profunda femoris artery?
Perforating branches
Lateral femoral circumflex arteries
Medial femoral circumflex arteries
What does the perforating branches supply?
main branches:
Perforating branches – Consists of three or four arteries that perforate the adductor magnus, contributing to the supply of the muscles in the medial and posterior thigh
What does the lateral femoral circumflex arteries supply?
Wraps round the anterior, lateral side of the femur, supplying some of the muscles in the lateral side of the thigh.
What does the medial femoral circumflex arteries supply?
Medial femoral circumflex artery – Wraps round the posterior side of the femur, supplying the neck and head of the femur
What is the potential complication of fracturing the femoral neck?
The medial femoral circumflex artery can be easily damaged leading to avascular necrosis of the femur head.
How does the femoral artery become the popliteal artery?
It passess through and out of the adductor canal by passing through the adductor hiatus in the adductor magnus muscle and become politeal artery behind the knee.
Why is it important to have genicular anastomosis around the knee?
Maintains blood supply to the leg during knee flexion which may impinge the popliteal artery
What 5 genicular branches from the popliteal artery form the genicular anastomosis?
Superior lateral Superior medial Middle Inferior lateral Inferior medial
What are the 3 arteries of the leg?
Anterior tibial arter
Posterior tibial artery
Fibular artery
What artery supplies the anterior compartment of the leg?
Anterior tibial artery which is terminal branch of popliteal artery
What artery supplies the posterior compartment of the leg?
Posterior tibial artery
Terminal branch of popliteal artery
What artery supplies the lateral compartment of the leg?
Fibular artery
Branch of posterior tibial artery
What are the two planes of the foot?
Dorsal aspect which is the top of the foot
Plantar aspect which is the sole of the foot
What supplies the dorsal aspect of the foot?
Dorsalis pedis artery
Continuation of anterior tibial artery
What supplies the plantar aspect of the foot?
Medial and lateral plantar arteries
Bifurcation of posterior tibial artery
What arteries form the deep plantar arch?
Anastomosis of deep plantar branch
of dorsalis pedis artery with lateral
plantar artery
How common is the superfecial plantar arch?
The superficial plantar arch only present in approx. 5% population
What are the 4 palpatations of the lower lip?
Femoral
Popliteal
Posterior tibial
Dorsalis pedis
Why is femoral artery a important access point?
A catheter can be placed into the femoral artery which can then be advanced up the arterial tree to target organ.
Also can do arterial blood gas from femoral artery
What invasive treatments can be done by access to the femoral artery?
This provides minimally invasive access to perform procedures including:
Coronary angiography
Coronary angioplasty
Embolisation of berry aneurysms
What is the position of the femoral artery in the femoral triangle?
The most superficial in the femoral triangle
Between the femoral nerve and vein.
Vulnerable to injury/laceration
What can occlude the lower limb arteries?
By embolus or thrombus
What are the causes of acute ischaemia of the lower limb?
Usually acute occlusion by thrombus or emboli; can also be caused by trauma or compartment syndrome
Is acute ischaemia of lower limb a medial emergency?
Yes need to treat within 4-6 hours. Require urgent revascularisation –> if not then get necrosis and need amputation.
What is the presentation of acute ischaemic leg?
The 6 P’s Pain Pallor = pain Perishingly cold Pulseless Paraesthesia Paralysis
What is the treatment of acute ischaemic leg?
Depends on the cause, but
Revascularisation required to prevent irreversible tissue loss
Imaging will show the site of occlusion
Atherosclerotic changes often occur at lower femoral artery
Collateral circulation via anastomoses between branches of profunda femoris and popliteal
A graft from the common femoral to popliteal can bypass an occluded vessel
What is the process of chronic ischaemia developing?
Asymptomatic Intermittent claudication – mild Intermittent claudication - severe Rest pain / night pain Tissue loss / ulceration / gangrene
What are the superfecial veins of the lower limb?
Great and short saphenous veins
Lie in subcutaneous tissue, superficial to deep fascia
Drain into deep veins (femoral and popliteal)
What are the 3 odeep veins of the lower lib which are venae comitantes?
Anterior and posterior tibial veins and the fibular vein
How is the popliteal vein formed and in turn the femoral vein?
Anterior and posterior tibial veins and the fibular vein join to form the popliteal vein which in turn becoems the femoral vein
What is the role of perforating veins?
Drain blood from the superficial veins to the deep veins
Contain valves to prevent backflow
How is venous return from deep veins aided?
muscular contraction - ‘muscle pump’
deep fascia - ‘compression stocking’
If the valves don’t prevent backflow in the perforating veins what is the outcome?
Varicose veins
When would femoral vein be used for emergency Iv access?
Temporary access:
Trauma
Burns
Otherwise very difficult access (shock, IVDU, thrombosed peripheral veins, obesity)
Can be used for venepuncture in emergencies
What is the great saphenous vein and when is it used?
Lies immediately in-front of the medial malleolus
Site can be used in emergencies to obtain IV access
What causes the increase pressure in the saphenous vein?
Can be caused by proximal venous obstruction e.g. pregnancy or pelvic tumour
Increase pressure in the saphenous vein can cause varicose vein what is the process?
The veins become dilated and incompetent
Blood then may stagnate in the skin – leading to breakdown and ulceration
What are the complications of varicose veins?
Bleeding
Superficial thrombophelbitis
Venous / varicose ulcers – medial side of the ankle, dermatitis and skin thickening
Risk factors for DVT?
Previous VTE Immobility Recent surgery Malignancy Pregnancy IV drug use (injecting into femoral vein) Sepsis
What forms the lumbar plexus?
Formed from anterior rami of L1 – L4
What forms the sacral plexus?
Formed from anterior rami of L4 – S5
What is the lumbosacral trunk?
Branch of L4 and anterior ramus that joins L5.
What does the lumbar plexus give rise to?
Obturator nerve (L2-L4) Femoral nerve (L2-L4)
What does the sacral plexus give rise to?
Sciatic nerve (L4-S3) Superior (L4-S1) and inferior (L5-S2) gluteal nerves
What does the femoral nerve supply?
Anterior compartment of the thigh?
How does the femoral nerve enter the thigh and what is its terminal branch?
Passes under inguinal ligament to enter thigh
Terminal branch is saphenous nerve which passes through adductor hiatus to supply skin of medial leg
What does the obturator nerve supply?
Supplies the medial compartment of the thigh
What does the obturator nerve divide into?
Divides into anterior and posterior branches that lie on either side of adductor brevis
What does the sciatic nerve supply?
Supplies posterior thigh and all of the leg and foot
What nerve does the sciatic nerve split into?
Tibial nerve (anterior divisions of anterior rami)
Common fibular nerve (posterior divisions of anterior rami
Where does the sciatic nerve bifurcate?
Usually bifurcates in distal thigh, however, already separate as leave the pelvis in 12% population
How is sciatic nerve injured?
The sciatic nerve is at risk of iatrogenic injury during intramuscular injections
IM injections must only be performed in superolateral quadrant
Also at risk in hip injuries / dislocations
What does the common fibular nerve bifurcate into?
Common fibular nerve bifurcates into superficial and deep branches
What does the superior and deep branch of common fibular nerve supply?
Superficial branch supplies lateral compartment of the leg
Deep fibular supplies anterior compartment of the leg
What nerve is most commonly injured in the lower limb and what is the outcome?
The common fibular nerve is commonly injured nerve in lower limb due to superficial position as it winds round the neck of the fibula
Injury Paralysis of dorsiflexor muscles resulting in ‘footdrop’
Have to alter gait to compensate
What does the tibial nerve supply?
The posterior compartment of the leg
Where does the tibial nerve birfurcate?
Bifurcates deep to the flexor retinaculum into medial and lateral plantar nerves
What does the medial and lateral planter nerves supply?
Medial plantar nerve is smaller than lateral – only supplies 4 muscles but supplies skin to medial 3 ½ digits
Lateral plantar nerve supplies all other plantar muscles and skin to lateral 1 ½ digits
What is the name of the openining in which the long (great) saphenous vein passess through in the deep fascia?
Saphenous hiatus or saphenous opening
What is the borders of the femoral triangle?
Superior border – Formed by the inguinal ligament
Lateral border – Formed by the medial border of the sartorius muscle. Medial border – Formed by the medial border of the adductor longus muscle.
What is the content of the femoral triangle? From lateral to medial
The femoral nerve is most lateral, then the femoral artery then the femoral vein.
Most medially is the lymphatic’s so the inguinal lymph nodes surrounded by fat
What muscles are innervated by the femoral nerve?
All of the muscles in the anterior compartment of the thigh and have branches that supply the ilaecus and pectinues muscles
What is the chief functions of the medial muscels of the thigh?
Except for obturator externus mainly adduct the thigh at the hip joint
where is adductor hiatus located?
Between adductor magnus msucel and hamstring
What are the attachments of the inguinal ligament
From the anterior superior iliac spine to the pubis tubercle.
What forms the roof and floor of the femoral triangleʔ
Floor is the pectineus and iliopsoas
The roof is the fascia lata
What surrounds the femoral artery and vein in the femoral triangleʔ
The femoral sheath
What type of vein is the great Saphenous vein and where does it drain into
Superficial vein that drains into the femoral vein
What forms the adductor hiatusʔ
Formed between hamstring muscles and adductor part of adductor Magnus
What are the boundaries of adductor canalʔ
Anterior is Sartorius
ʟaterally is vastus medialis
Posterior is adductor longus and adductor magnus
What does vastuc lateralis, medialis and rectus femoris formʔ
Form a patella tendon that attaches into the patella
Define intermittant claudication?
It is aching, cramping, tired and sometime burning pain in the leg that comes and goes
The rough dermatome of the lower limb?
over the inguinal ligament-L1; lateral side of the thigh-L2; lower medial side of the thigh-L3; medial side of the great toe (digit I)-L4; medial side of digit II-L5; little toe (digit V)-S1; back of the thigh-S2; and skin over the gluteal fold-S3.
What is the myotome of lateral and medial rotation of the hip?
Lateral is L5,S1
Medial is L1,2,3
What is the myotomes of abduction and adduction of the hip?
Abduction is L5,S1
Adduction is L1,2,3,4
What is the myotomes of dorsiflexion and plantarflexion of the foot?
Dorsiflexion is L5,S1
Plantarflexion is S1,S2
What is myotomes of inversion and eversion of the foot?
Inversion is L4,5
Eversion is L5,S1
What is the myotomes of extension and flexion of the hip?
Extension of the hip is L4,5
Flexion of the hip is L1,2,3
What is the myotomes of extension and flesion of the knee?
Extension is L5,S1
Flexion is L3,4
What is the myotomes of dorsiflexion and plantarflexion of the ankle?
Dorsiflexion is L4,5
Plantarflexion is S1,S2
What are the attachments of the inguinal ligament?
The ASIS to the pubic tubercle
why is the anatomy of the femoral triangle important clinically?
For vascular access
Femoral hernia
Vascular surgery
Lymphatic spread of disease
What are the borders of the femoral triangle?
Superiorly is inguinal ligament Laterally is Sartorius muscle Medially is Adductor longus muscle Roof is fascia lata Floor: laterally is iliopsoas and medially it is Adductor longus and pectineus
What is the content of the femoral triangle?
Femoral nerve, artery and vein.
Also have inguinal lymph nodes surrounded by fat.
Most lateral is the femoral nerve –> artery –> vein and finally most medial is the lymph nodes.
The profunda femoral artery origniates within the femoral traingle
The great saphenous vein runs medially up the whole of the leg and drains into the femoral vein
What is the boundaries of adductor canal?
Anteriorly (roof) is sartorius muscle
Laterally is vastus medialis
Posteromedially is adductor longus and magnus
What is the borders of adductor haitus?
Formed between the hamstring and the adductor part of adductor magnis
What runs through adductor canal?
The adductor canal carries the femoral vessels and saphenous vein that run between femoral triangle and popliteal fossa
What is the pes ansenrinues?
It is the medial surface of the tibia where the gracillis, semitendinosus and sartorius form a common tendon onto the tibia
What do all the muscles that attach to the pes anserinus have in common?
They all cause flexion of the leg at the knee
What vessels are invovled in the cruicate anastomosis?
Anastomosis between branches of the internal iliac and profunda/deep femoris arteries
Superior and inferior gluteal arteries
Lateral and medial circumflex femoral artery
1st perforating artery
What is the function of the cruciate anastomosis?
Clinically important – allows blood to bypass a blockage of the external iliac or proximal femoral arteries
What nerve supplies the heal?
Medial calcaneal branch of the tibial nerve which arises from the tensor tunnel innervates the skin over the heel
How is the Sural nerve formed and what does it innervate?
The tibial nerve gives a cutaneous branch which unites with a branch of the common fibular nerve.
This sensory nerve suppleis the posterolateral side of the leg and the lateral side of the foot.
