Lumbosacral plexus
innervation of the entire lower extremities
[ ] L1-4 = anterior innervation
[ ] L5-S4 = posterior innervation
Femoral nerve
L2-4 –> anterior thigh and medial foot
Lateral femoral cutaneous nerve
L1-3 –> lateral skin of thigh
Obturator nerve
L2-4 –> Adduction and inner thigh
Femoral nerve block
L2-4 –> inguinal ligament, sartorius, adductor longus
- gives some weakness to quads
Nerve stim femoral
Firing of quads
- cephalad direction just lateral to artery just below the inguinal ligament
U/S femoral
lateral to the vessels
- in-plane block
Fasci Iliaca
inserted into the fascia iliaca on the lateral 2/3 and pass through 2 pops
LFCN block
it travels laterally through the psoas –> emerges inferior and medial to ASIS
Psoas block
useful to cover femoral, obturator and LFCN (spares the sciatic nerve)
- DEEP block in muscle beds, possibility for epidural/intrathecal spread
- lateral decubitus position with operative side up
Saphenous block/Adductor Canal
blocks most medial branch of femoral nerve
- innervates medial thigh toward knee and inner lower leg
- useful for pain at/below knee
Trans-sartorial AC
at junction of sartorius, vastus medialis, adductor magnus
Proximal Saphenous
distal to tibial tuberosity and direct medially
Sciatic Block
L4-S3 –> blockade of posterior leg
- good analgesia and lacks sympathectomy
- great coverage of lateral foot
Popliteal block
great coverage of foot and ankle –> spares the hamstrings
Nerve stim popliteal
posterior approach –> 1 cm caudad needle entry from opening of biceps femoris and semimembranous
-> plantar flexion
U/S popliteal
popliteal artery is most anterior structure
- nerve is posteriolateral to vessels
- peanut nerve bundle
Ankle block
- great coverage of foot, avoid high volume and epi 5 injections: 1. saphenous 2. deep peroneal 3. superficial peroneal 4. Posterior Tibial 5. Sural
