Ankle block

Ankle block anesthetizes four branches of the sciatic nerve (superficial peroneal, deep peroneal, posterior tibial, and sural nerves) and one cutaneous branch of the femoral nerve (saphenous nerve). Each nerve is independently anesthetized.
The deep peroneal nerve innervates the first webspace of the foot. The dorsalis pedis artery is palpated and the needle inserted just lateral to the extensor hallucis longus tendon.
The superficial peroneal nerve supplies the skin over the dorsum of the foot and is blocked by subcutanous infiltration over the dorsum of the foot starting from the injection site for the deep peroneal nerve (above).
The posterior tibial nerve provides sensation to the calcaneus and sole of the foot. It is anesthetized by injecting local anesthetic behind the medial malleolus.
The sural nerve provides cutaneous sensation over the lateral ankle, foot, and fifth toe and is adjacent to the small saphenous vein. It is blocked by injecting local anesthetic behind the lateral malleolus.
The saphenous nerve supplies sensation to the skin over the medial aspect of the ankle and foot. It is blocked by injecting a ring of local anesthetic around the great saphenous vein.

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