The femoral nerve block is one of the most clinically applicable nerve block techniques that it is relatively simple to perform, carries a low risk of complications, and results in a high success rate.
Femoral nerve block is well suited for surgery on the anterior aspect of the thigh and for superficial surgery on the medial aspect of the leg below the knee. Some examples include repair of the quadriceps tendon or quadriceps muscle biopsy, long saphenous vein stripping, and postoperative pain management after femur and knee surgery. A perineural catheter can be placed to provide prolonged analgesia for patients with fractures on the femoral neck or shaft. Femoral nerve block provides effective analgesia following total knee arthroplasty. Femoral nerve block can also be used to supplement a sciatic or popliteal block to provide complete anesthesia of the lower leg and ankle.1,2,3,4
The primary indication of continuous femoral nerve block is pain management after major femur or knee surgery.5-21
In addition, when compared with a single-dose technique or placebo, continuous femoral nerve block significantly reduces postoperative morphine consumption in patients having total hip replacement.22,23
Continuous femoral nerve block provides excellent analgesia in patients with femoral shaft or femoral neck fractures.13,14,20,24 Its relative simplicity makes it uniquely suitable for use to provide analgesia in the emergency room and facilitate physical and radiologic examinations as well as manipulations of the fractured femur or hip.
After major knee surgery, continuous femoral nerve block provides better pain relief than parenteral administration of opioids (IV PCA, intramuscular)6,11,15,16,19 or intra-articular analgesia.17,25 For knee surgery, continuous femoral block is as effective as continuous lumbar plexus block26 or continuous epidural analgesia,11,19 but causes fewer complications.27
Relative contraindications for femoral nerve block include previous ilioinguinal surgery (femoral vascular graft, kidney transplantation), large inguinal lymph nodes or tumor, local infection, peritoneal infection, and preexisting femoral neuropathy.
The femoral nerve is the largest branch of the lumbar plexus. It is formed by the dorsal divisions of the anterior rami of the L2, L3, and L4 spinal nerves. It emerges from the lateral border of the psoas muscle, approximately at the junction of the middle and lower thirds of that muscle. Along its course to the thigh, it remains deep to the fascia iliaca. It enters the thigh posterior to the inguinal ligament, where it is positioned immediately lateral and slightly posterior to the femoral artery (Figure 82C–1). At this level, it is situated deep to both ...