Fascia Iliaca Block

Blockade is:

Indications

Analgesia for:

Innervation of the lower extremities occurs via the lumbosacral plexus, which divides into the:

The sciatic nerve:

Arises from L4-S3
Directly provides:
- Motor supply to the posterior compartment of thigh
- Sensory supply to posterior thigh
Divides at a variable location (but usually close to the popliteal fossa) into the:
- Common peroneal nerve
  Divides at the knee into two branches which provides sensation to the posterolateral leg:
  - Superficial peroneal nerve
    Provides sensation to dorsum of foot and toes.
  - Deep peroneal nerve
    Provides sensation to the web space between the great and second toe.
- Tibial nerve
  Innervates the posterior compartment and sole of the foot. Gives off the:
  - Sural nerve
    Provides sensation to the heel, back of the ankle, and the lateral malleolus.
  - Posterior tibial nerve

The femoral nerve:

Arises from L2-4
Largest branch.
Directly provides:
- Motor supply to knee extensors
- Sensory supply to anteromedial thigh
Divides into the:
- Obturator nerve
  Formed from L2-4, and enters thigh through obturator foramen. Provides:
  - Motor supply to hip adductors
  - Sensory supply to a variable aspect of the medial thigh/knee
- Lateral femoral cutaneous nerve
  Formed from L2-3, and runs on ventral surface of iliacus, beneath fascia iliaca. Provides:
  - Sensory supply to lateral aspect of thigh and knee
- Saphenous nerve
  - Lies in the adductor canal, close to the femoral artery and vein
    Deep to sartorius and superficial to vastus medialis.
    - Typically not visible on ultrasound
      May be seen as a small, round, hyperechoic structure medial to the artery.
    - Typically 2-3cm deep
  - Entirely sensory nerve, providing sensation to medial lower leg and ankle.

Standard nerve block tray
High-frequency linear probe
5-10cm blunted, short-beveled, or Tuohy needle
Blunted needles improve tactile feeling of block.
40ml local anaesthetic

Can be either:

Landmark
Easy and reliable, but high volume of LA required.
Ultrasound
Greater equipment requirement but associated with lower risk of complications.

Position patient supine
Identify landmarks:
- ASIS
- Pubic tubercle
Divide distance between ASIS and tubercle into thirds
Mark a point 1cm caudal from the junction of the lateral and middle third
Confirm that this point is ~1-2cm lateral to the femoral pulse.
Standard prep, drape, skin anaesthesia, etc
Perform block:
- Insert needle perpendicularly
- Angle slightly cranio-medially to avoid vessels
- Advance needle slowly, feeling for two pops
  - Distinct pop through fascia lata
  - Subtle pop through fascia iliaca
- Flaten needle and insert a further 1-2mm
- Aspirate and inject in 5ml aliquots
  - No resistance to injection should be appreciated
    Resistance suggests needle is within iliacus - withdraw until injection is easy.

Position patient supine
Identify femoral vessels
Follow fascia iliaca laterally to the ASIS
Identifed as the thick fascial plane superficial to the femoral nerve and femoral vessels.
Perform block
- Insert needle IP from the lateral side
- Aim to place needle tip under the fascia iliaca at the junction of the middle and lateral thirds of the line between the ASIS and pubic tubercle
  As per landmark technique. Pops are usually perceived.
- Aspirate and inject 1-2ml of LA to confirm location with hydrodissection of fascia
- Inject remainder of LA in 5ml aliquots (aspirating between)
- Aim is to identify spread both:
  - Laterally towards iliac crest
  - Medially towards femoral nerve

Range C, Egeler C. Fascia Iliaca Compartment Block: Landmark and Ultrasound Approach. WFOSOA. 2010.
Chuan A, Scott DM. Regional Anaesthesia: A Pocket Guide. 1st Ed. Oxford University Press.
NYSORA. Ultrasound Guided Fascia Iliaca Block. Accessed September 2018.