Lower Extremity PNB Flashcards
Where is the lumbosacral plexus located?
L1-S5 (may include T12).
Where is the iliohypogastic nerve formed?
T12-L1
Where does the iliohypogastric nerve travel?
In abdominal wall to level of the symphysis pubis.
What does the iliohypogastric nerve innervate?
Muscle, skin, and patietal peritoneum.
Skin over inferior abdomen and buttocks.
What PNB should be done for inguinal hernias?
May need both ilioinguinal and iliohypogastric blocks.
Where is the ilioinguinal nerve formed?
T12-L1.
Where does the ilioinguinal nerve travel to and from?
Travels in abdominal wall, pierces posterior wall of the inguinal canal, passes through superficial inguinal ring, terminates on the anterior scrotum/labia majora.
What does the ilioinguinal nerve innervate?
Muscle, skin, parietal peritoneum.. Skin of superior/medial thigh, portions of external genitalia.
Where is the genitofemoral nerve formed?
L1-L2
Where does the genitofemoral nerve travel to and from?
Travels in abdominal wall. Though deep inguinal canal and through superficial inguinal ring. Terminates on anterior scrotum/labia majora.
What does the genitofemoral nerve innvervate?
Skin covering femoral hiatus. Skin on the scrotum and labia majora
What type of procedures is the genitofemoral nerve typically blocked for?
Mostly urinary and genital procedures
What are the three muscles layers on our sides/front flanks?
External oblique, internal oblique, and transverse abdominus.
In between what two muscle layers do most of the nerves run in between?
Between the internal oblique and transverse abdominus.
After coming to the front of the body, where do the nerves lie?
Right over top the rectus abdominus
Which block is used for episiotomy?
Pudendal nerve block.
Where does the pudendal nerve originate?
S2-S4.
Where does the pudendal nerve travel from and to?
Passes from pelvis through greater sciatic foramen into gluteal region. Passes posterior to ischial spine and into perineum.
What does the pudendal nerve innervate?
Muscle and skin of perineum.
Where does the lateral femoral cutaneous nerve originate from?
Posterior division of L2-L3.
Where does the lateral femoral cutaneous nerve travel from and to?
Descends posterior abdominal wall, crosses iliac crest into pelvis and down to inguinal ligament and anterior iliac spine.
What does the lateral femoral cutaneous nerve innervate?
Skin- lateral aspect of thigh to the level of the knee.
Where is the block typically performed at for lateral femoral cutaneous nerve block?
In the lateral groin area.
Where does the posterior femoral cutaneous nerve originate?
Anterior and Posterior division of S1-S3
Where does the posterior femoral cutaneous nerve travel from and to?
Passes from pelvis into gluteal region to posterior thigh.
What does the posterior femoral cutaneous nerve innervate?
Skin of posterior thigh (hip to mid-calf).
Which nerve actually innervates the hip and controls adduction, flexion, and extension of hip?
Obturator nerve
Where does the obturator nerve originate?
Anterior division of L2-L4
What does the obturator nerve innervate?
Many muscles in thigh. Articular branches to hip= controls adduction, flexion, and extension of hip.
Skin of medial thigh.
Where does the femoral nerve originate?
Posterior division of L2-L4
Where does the femoral nerve split into anterior and posterior branches?
Below inguinal ligament
Which split (anterior/posterior) of the femoral nerve contains the saphenous nerve?
The posterior
Describe the femoral nerve’s relation to femoral artery and vein.
Nerve is most lateral to femoral artery and vein.
What is the mnemonic to remember femoral nerve location?
VAN
Vein,
Artery,
Nerve
V=venous penis or V=Vagina.
Which muscle wraps from lateral to medial across the thigh?
Sartorius
Which muscle goes straight down the thigh?
Rectus femoris.
Which nerve is typically blocked within the adductor canal directly under the sartorius muscle?
Saphenous nerve
Which muscles are innervated by the femoral nerve?
Rectus femoris. Vastus lateralis. Vastus intermedius. Vastus medialis. Sartorius.
Where does the saphenous nerve originate?
Posterior cutaneous branch from femoral nerve.
What nerve would be stimulated if sartorius muscle contraction or patellar twitch occurs?
Femoral nerve.
If saphenous nerve is blocked, will it be motor block/sensory block/or both?
Sensory block
What structure does the saphenous nerve follow/accompany?
Saphenous vein/artery
What does the saphenous nerve innervate?
Medial leg from knee to the arch of the foot.
What two nerves form the sciatic nerve?
Tibial Nerve and Common Peroneal Nerve.
Where does the sciatic nerve branch off again?
Popliteal fossa.
Where does the popliteal nerve originate?
Trick question. No popliteal nerve.
What is a popliteal block?
Block of the sciatic nerve at the popliteal fossa which is near the popliteal artery.
Where does the tibial nerve originate from?
Anterior division of L4-S3.
What does the common peroneal nerve branch into?
Superficial and Deep.
Which branch of the common peroneal nerve passes in front of the ankle and terminates between great toe and second toe?
Deep peroneal nerve
Where does the superficial peroneal nerve run?
Stays at the front of the leg into the front of the foot.
Which nerve is formed from the union of the tibial and common peroneal?
Sural Nerve.
What nerve does the sural nerve travel with?
Saphenous nerve.
What does the sural nerve innervate?
Posterior sole of foot.
Posterior heel.
Achilles tendon above ankle.
What five nerves extend all the way to the ankle?
Sural, deep peroneal, tibial, saphenous, superficial peroneal.
Which of the five nerves that extend to the ankle run subcutaneously and which run deep?
The “S”s are superficial
Sural.
Saphenous.
Superficial peroneal.
Non-“S”s run deep.
Deep Peroneal and tibial.
Where does the sural nerve terminate in the ankle?
Posterior to lateral malleolus
Which nerve runs posterior to the medial malleolus?
Tibial nerve.
Which two nerves run at the front of the ankle?
Deep peroneal (deeper) and Superficial peroneal (subcutaneous).
Stimulation of deep peroneal will cause what foot response?
Straight up.
Stimulation of tibial nerve will cause what foot response?
Down and inward.
Which nerve stimulation will cause outward and upward foot movement?
Superficial peroneal.
T/F: Femoral nerve block is good for knee arthroscopy?
True; but not good for knee arthroplasty
What are contraindications for femoral nerve block?
Previous ilioinguinal surgery.
Large inguinal lymph node/tumor.
Local infection.
Neuropathy
What are indications for femoral nerve block?
Anterior aspect of thigh.
Superficial surgery on medial aspect of leg and below knee.
Knee arthroscopy
What are indications for popliteal block?
Lower leg surgery especially lateral.
Especially foot and ankle.
May also require saphenous coverage.
