A7 - Lower limb bones & NV supply Flashcards
What arteries are at risk of damage with fractures of the femur?
Medial and lateral circumflex arteries
Which artery contributes to vascular anastomoses around the knee joint?
Descending genicular arteries
What bones contribute to the medial longitudinal arch of the foot?
Calcaneus, talus, navicular, 3 cuneiforms and the first 3 metatarsals
What bones contribute to the lateral longitudinal arch of the foot?
Calcaneus, cuboid, 4th and 5th metatarsals
Describe the course of the femoral artery
1- External iliac becomes the femoral artery when it enters the femoral triangle by passing under the inguinal ligament
2- Gives off profunda femoris branch within the femoral triangle
3- Passes through the adductor canal under the sartorius
4- Passes through adductor hiatus
5- Enters popliteal fossa and becomes the popliteal artery
What are the branches of the femoral artery?
Do Princesses Sew Sweet Superhero Dresses
Descending genicular arteries
Profunda femoris artery (deep femoral)
Superficial epigastric
Superficial circumflex iliac artery
Superficial external pudendal artery
Deep external pudendal arteries
What are the branches of the popltieal artery?
Anterior tibial
Posterior tibial
Fibular artery (may come off posterior tibial in some people)
What arteries supply the anterior, posterior and lateral compartments of the leg?
Anterior = anterior tibial
Posterior = posterior tibial
Lateral = fibular artery
What are the 2 main superficial veins of the leg? What side of the leg are they found and where do they drain into?
Great saphenous vein = MEDIAL
- Drains into femoral vein
Short saphenous vein = LATERAL
- Drains into popliteal vein
What does the anterior tibial artery eventually become?
Dorsalis pedis artery
What does the posterior tibial artery eventually become?
Medial and lateral plantar arteries (bottom of foot)
Which bone forms the heel of the foot?
Calcaneus
What articulates at the proximal tibiofibular joint?
Head of fibular articulates with the lateral condyle of the tibia (tibial ‘plateau surface’)
What type joint is the proximal tibiofibular joint?
Plane type synovial joint
What articulates at the distal tibiofibular joint?
Fibular articulates with the fibular notch of the tibia
What articulates at the ankle joint?
1: Distal end of tibia with trochlear of talus
2: Medial malleolus of tibia with medial surface of talus
3: Lateral malleolus of fibular with lateral aspect of talus
What are the bones of the foot?
7 tarsal bones: calcaneus, navicular, talus, cuboid, 3 cuneiforms (medial, intermediate, lateral)
5 metatarsals: 1= big toe, 5 = little toe
3 phalanges for each toe, except the big toe (2)
Which bone of the foot is at highest risk of avascular necrosis and why?
Talus - as no muscles attach here
Which tarsal bones of the foot are in the proximal and distal rows?
Proximal = calcaneus, navicular, talus
Distal = cuboid, 3 cuneiforms - medial, intermediate and lateral
What bones contribute to the transverse arch of the foot?
Metatarsal bones, cuboid and 3 cuneiform bones
What is pes cavus?
Unusually high medial longitudinal arch, impairs the ability to shock absorb while walking = increased stress on ball and heel of foot
What is pes planus?
Longitudinal arches have been lost, may cause few symptoms or can cause pain in children, aching in adults
What branches does the deep femoral (profunda femoris) artery give off?
‘Let Me Pass’
- Lateral circumflex femoral artery
- Medial circumflex femoral artery
- Perforating branches
What artery supplies the medial compartment of the thigh and where is it derived?
Obturator artery
From the internal iliac artery
What forms the deep plantar arch? What does it supply?
Dorsalis pedis
Lateral plantar artery
= Deep plantar arch supplies the toes
What are the 3 main nerves of the lower limb and where do they arise?
Sciatic = L4-S3
Femoral = L2-L4
Obturator = L2-L4
What are the branches of the sciatic nerve and where do they supply?
Divides into common fibular (peroneal) and posterior tibial nerves. Common fibular divides into superficial and deep peroneal nerves:
- Posterior tibial = posterior compartment of leg
- Superficial peroneal = lateral compartment of leg
- Deep peroneal = anterior compartment of leg
What nerve if damaged would cause foot drop?
Common fibular nerve
Where does the obturator nerve provide motor and sensory innervation?
Motor: medial muscles of thigh, except hamstring portion of adductor magnus
Sensory: skin over proximal part of medial thigh
Where does the femoral nerve provide motor and sensory innervation?
Motor: anterior muscles of thigh
Sensory: supplies cutaneous branches to anteromedial thigh and medial side of leg and foot
Where does the sciatic nerve provide motor and sensory innervation?
Motor: posterior muscles of thigh
Sensory: lateral leg and foot via terminal branches
Where would a patient lose feeling if they lost S3 and S4 sensory innervation?
condition called ‘saddle anaesthesia’ = patient experiences urinary incontinence and loses all feeling in that area, i.e. cannot feel when they wipe
How can you tell if a femur is a L or R one?
Head inserts medially, then from the top to bottom it should angle inwards
Also has linear aspera (thick ridge) on posterior surface
Where is the quadrate tubercle found?
On the intertrochanteric crest of the femur
How can you tell if the tibia is a L or R one?
Inferior end has medial malleolus
Superior end has ‘tibial tuberosity’ - prominent bulge on anterior side
What is found between the medial and laeral condyles of the tibia?
Intercondylar tubercles (/ eminence) = bumpy
How can you tell if the fibular is a L or R one?
Hold it by its head (thicker end) in your right hand, then position the lateral malleolus so it is facing laterally - if the malleolar fossa (indentation on distal end) is facing towards you = R one, if away from you = L
How can you orientate a patella?
Has an apex that points down, then the anterior surface is rough, and the posterior surface is smooth
