Station 3: Neurovasculature of the lower limbs Flashcards
Where does the external iliac artery become the femoral artery?
Crosses under the inguinal ligament and enters the femoral triangle
Where does the femoral artery become the popliteal artery?
Popliteal fossa
Where does the popliteal artery normally bifurcate into the anterior tibial artery and tibioperoneal trunk (posterior tibial and fibular arteries)?
Lower border of the popliteus
Where are the anterior and posterior tibial arteries located?
Posterior tibial artery continues inferiorly (posterior of leg) along surface of deep muscles, accompanies the tibial nerve in entering the sole of the foot
Anterior tibial artery passes anteriorly between tibia and fibula, through the interosseous membrane, then becomes dorsalis pedis artery in the foot.
What are the common sites for compression of the arteries of the lower limb to prevent haemorrhage?
Femoral artery - superficially within the femoral triangle
What are the borders of the femoral triangle?
Superior: inguinal ligament (runs from anterior superior inguinal spine to the pubis tubercle)
Lateral: medial border of sartorius
Medial: medial border of adductor longus
Which structures run in the femoral triangle?
Femoral nerve
Femoral artery
Femoral vein (great saphenous drains here)
Femoral canal (deep lymph nodes and vessels)
Which structures run within the fascial compartment known as the femoral sheath?
Femoral artery
Femoral vein
Femoral canal
How would you locate the femoral vein in a patient without ultrasound?
Medial to pulsatile femoral artery
Nb NAVEL
Where does the sciatic nerve originate?
Lumbosacral plexus: L4-S3
What is the course of the sciatic nerve?
It leaves the pelvis and enters the gluteal region via the greater sciatic foramen -> posterior thigh -> apex of popliteal fossa (terminates here into the tibial and common fibular nerves)
What are the motor and sensory functions of the sciatic nerve?
Motor:
DIRECTLY: Posterior compartment of the thigh, hamstring portion of adductor magnus (hip extension) - hip extension
INDIRECTLY: via tibial nerve (posterior leg and some intrinsic muscles of foot), via common fibular nerve (anterior leg, lateral leg, remaining intrinsic foot muscles) - knee flexion, all ankle and foot movements?
Sensory:
No direct sensory
INDIRECT - via tibial nerve (posterolateral and anterolateral sides of leg, plantar (sole) surface of foot), via common fibular nerve (lateral leg and dorsal surface of foot)
Where is the sciatic nerve commonly injured?
Posterior to hip joint in gluteal region with posterior dislocation of the hip
What are the roots of the femoral nerve?
L2-L4
Enters the pelvis under the mid-point of the inguinal ligament
What are the motor functions of the femoral nerve?
Anterior thigh (flex hip) Quadriceps femoris (extend the knee)
What are the sensory functions of the femoral nerve?
Anteriomedial thigh
Medial side of the leg and foot (saphenous nerve)
Where is the common injury site of the femoral nerve?
Not sure tbh!
Think it is uncommon but lets go - directly injury to the femoral triangle e.g. stab or would a pelvic fracture do it
What are the nerve roots for the tibial nerve?
L4-S3
What are the sensory functions of the tibial nerve?
Skin of the posterolateral side of the leg, lateral side of the foot, sole of the foot
What are the motor functions of the tibial nerve?
Posterior compartment of the leg - flex toes, plantar flexes ankle, flex knee, assists inversion of foot
Where would you damage the tibial nerve?
Posterior to medial malleolus (tibial nerve compressed within the tarsal tunnel - could happen post-trauma ankle deformities)
What clinical manifestations would you have with a damage to the tibial nerve?
Loss of plantar flexion, loss of flexion of toes and weakened inversion
What are the nerve roots of the common fibular nerve?
L4 - S3
What are the motor functions of the common fibular nerve?
DIRECTLY: Short head of biceps femoris
INDIRECTLY: muscles in lateral and anterior compartments of the leg
