FASCIA ILIACA BLOCK AT A GLANCE
Indications: anterior thigh and knee surgery, analgesia following hip and knee procedures
Transducer position: transverse, close to the femoral crease and lateral to the femoral artery (Figure 33B–1)
Goal: medial–lateral spread of local anesthetic underneath the fascia iliaca
Local anesthetic: 20–40 mL of dilute local anesthetic (eg, 0.2% ropivacaine)
Needle insertion for the fascia iliaca block. The blue dot indicates the position of the femoral artery. (Reproduced with permission from Hadzic A: Hadzic’s Peripheral Nerve Blocks and Anatomy for Ultrasound-Guided Regional Anesthesia, 2nd ed. New York: McGraw-Hill, 2011.)
The fascia iliaca block (also called the fascia iliaca compartment block) is considered an alternative to a femoral nerve or a lumbar plexus block. Since the femoral nerve and lateral femoral cutaneous nerve (LFCN) lie under the fascia of the iliacus muscle, a sufficient volume of local anesthetic deposited deep to the fascia iliaca may spread underneath the fascia in a medial and lateral direction to reach the femoral nerve and sometimes the LFCN.
Although some authors suggest that the local anesthetic may also spread underneath fascia iliaca proximally toward the lumbosacral plexus, this has not been demonstrated consistently. Before ultrasound (US), the technique involved needle placement at the lateral third of the distance from the anterior superior iliac spine to the pubic tubercle, using a “double-pop” technique as the needle passes through the fascia lata and fascia iliaca. However, block success with this “feel” technique is sporadic because false “pops” can occur. In contrast, the US-guided technique allows monitoring of the needle placement and local anesthetic delivery and ensures delivery of the local anesthetic into the correct plane.1
The fascia iliaca is located anterior to the iliacus muscle (on its surface) within the pelvis. It is bound superolaterally by the iliac crest and merges medially with the fascia overlying the psoas muscle. Both the femoral and lateral cutaneous nerves of the thigh lie under the fascia iliaca in their intrapelvic course. Anatomical orientation begins in the same manner as the femoral block: identifying the femoral artery at the level of the inguinal crease. If it is not immediately visible, sliding the transducer medially and laterally will eventually bring the vessel into view. Immediately lateral and deep to the femoral artery and vein is a large hypoechoic structure, the iliopsoas muscle (Figure 33B–2). It is covered by a hyperechoic fascia, which can be seen separating the muscle from the subcutaneous tissue superficial to it.
A panoramic view of the US anatomy of the femoral (inguinal) crease area. From lateral to medial, shown are the tensor fasciae latae muscle (TFLM), sartorius muscle (SaM), iliac muscle, fascia iliaca, femoral nerve (FN), and femoral ...