A block of the distal sciatic nerve provides surgical coverage for surgeries involving the posterolateral calf and foot regions with the exception of the medial ankle which is innervated primarily by the saphenous nerve.
Blockade of the sciatic nerve will result in diminished plantar and dorsal flexion strength of the foot and impair postoperative ambulation.
Local anesthetic is placed within the adductor canal (AC) to anesthetize the saphenous nerve and its branches in order provide sensory analgesic coverage of the anteromedial aspects of the lower extremity from the mid-thigh area to the foot.
A properly placed AC block can provide a quadricep muscle sparing, analgesic block of the lower extremity by avoiding proximal blockade of the femoral nerve.