INDICATIONS
- Anesthesia for procedures on the distal tibia and fibula, ankle, and foot
- Post-operative pain relief for procedures on the distal tibia and fibula, ankle, and foot
CONTRAINDICATIONS
- Absolute contraindications
- Patient refusal
- Allergy to local anesthetics
- Infection at the site of insertion
- Relative contraindications
- Coagulopathy or systemic anticoagulation
- Systemic infection
EQUIPMENT
- Standard anesthesia resuscitation equipment, including ECG, blood pressure and pulse oximetry monitors, suction, oxygen, and appropriate resuscitation drugs
- Sterile mask and gloves
- Sterile towels and gauze packs
- Two, 20-mL syringes with stopcocks
- Local anesthetic
- Tuberculin syringe with 25-gauge needle for local infiltration
- 22-gauge, 50 mm long, insulated stimulating needle
- Nerve stimulator with electrode
- Marking pen and ruler
ANATOMY
The sciatic nerve is formed by the union of the first three sacral spinal nerves and the 4th and 5th lumbar nerves. It is the largest of the four major nerves supplying the leg. The sciatic nerve leaves the pelvis through the greater sciatic foramen. It runs toward the posterior aspect of the thigh between the greater trochanter of the femur and the ischial tuberosity. At 60 mm +/- 30 mm above the popliteal crease it divides into its terminal branches the tibial nerve (supplying the heel and sole of the foot) and the common peroneal (also known as the common fibular) nerve (innervating the lateral aspect of the leg and dorsum of the foot). The only aspect of the lower leg not innervated by the sciatic nerve is the medial aspect of the leg below the knee, which is supplied by the saphenous nerve.
On the posterior aspect of the knee, the landmarks for performance of the popliteal block are the tendons of the semimembranosus and semitendinosus muscles medially, the biceps femoris laterally, and the popliteal crease inferiorly.
