- Anterior thigh and knee surgery.
- Well suited for surgery such on the anterior thigh, knee, quadriceps tendon repair, and postoperative pain management after femur and knee surgery.
- When combined with a block of the sciatic nerve, anesthesia of almost the entire lower extremity from the mid-thigh level can be achieved.
Femoral (inguinal) crease, femoral artery pulse
"VAN" (Yfront, vein, artery, nerve)
Distribution of Anaesthesia?
- A femoral block results in anesthesia of the entire anterior thigh and most of the femur and knee joint.
- The block also confers anesthesia of the skin on the medial aspect of the leg below the knee joint (saphenous nerve - a superficial terminal extension of the femoral nerve).
Goal with Nerve Stimulator?
The femoral nerve innervates a number of muscle groups. A visible or palpable twitch of the quadriceps muscle (patella twitch) at 0.2-0.5 mA current is the optimal response.
The most common response to nerve stimulation with this technique is twitch of the sartorius muscle. This results in a band-like contraction across the thigh without movement of the patella.
It should be kept in mind that sartorius muscle twitch is not reliable because the branches to the sartorius muscle may be outside the femoral sheath. When the sartorius muscle twitch occurs, the needle is simply redirected laterally and advanced several mm deeper.
LA choice and dose?
- 20-25ml allows for dispersal underneath fascia iliaca laterally and results also in block of the lateral femoral cutaneous nerve of thigh.
- The block of lateral cutaneous nerve of the thigh confers anesthesia to the lateral aspect of the thigh
- Type and concentration of local anesthetic should be based on whether the block is planned for surgical anesthesia or pain management.
- Long-acting local anesthetic should be avoided in ambulatory patients undergoing relatively minor procedures as ambulation is affected by prolonged motor block of the quadriceps muscle.
- A typical onset time for this block is 10-15 minutes, depending on the type, concentration, and volume of local anesthetic used.
- The first sign of onset of blockade is the loss of sensation of the skin over the medial aspect of the leg below the knee (saphenous nerve).