Sciatic and Popliteal Nerve Blocks

Abstract

Proximal sciatic nerve (L4–S3) blocks provide anesthesia/analgesia to the posterior aspect of the thigh, hamstring muscles, part of the hip and knee joints, and the entire leg below the knee, with the exception of the portion supplied by the saphenous nerve (anteromedial aspect of the lower leg and foot). The sciatic nerve bifurcates into its two branches – the tibial nerve and common peroneal nerve – as it courses in the popliteal fossa. Sciatic nerve blocks at a distal region will provide anesthesia/analgesia to the lower leg. Compared to central neuraxial blocks (e.g., caudal or epidural), peripheral techniques will have fewer undesirable side effects such as nausea and vomiting, urinary retention, hypotension, and bilateral muscle weakness and may increase the duration of analgesia. There are different approaches to anesthetizing the sciatic nerve at different locations along its course which are described in this chapter.