Common peroneal nerve blockade is useful as a diagnostic, prognostic, or therapeutic procedure in painful disorders involving the ankle and foot.
After informed consent is obtained, the patient is placed in the supine or lateral position. The common peroneal nerve can be easily palpated as it crosses the neck of the fibula. The patient is prepared in a standard aseptic fashion over an area large enough to allow palpation of landmarks, and sterile technique is used throughout the procedure. A 1-in. (2.5-cm), 25-gauge needle is inserted next to the nerve and advanced to contact the periosteum, with care being taken to avoid an intraneural injection. A sudden, intense pain on injection suggests intraneural injection. If this occurs, the needle should be repositioned before proceeding. A nerve stimulator may be used to identify the nerve by eliciting contraction of the anterior compartment muscles. The needle is withdrawn slightly, and after negative aspiration, 5 mL of local anesthetic is injected to block the peroneal nerve (see Fig. 67-17).
FIGURE 67-17. Tibial and common peroneal nerve block at the knee. Approach for tibial and common peroneal nerve injection and neural blockade at the knee. Tibial and common peroneal (lateral popliteal) nerve.
The common peroneal nerve is about half the size of the tibial nerve and contains articular branches to the knee joint. It provides motor innervation to the extensor muscles of the foot and cutaneous nerves to the lateral aspect of the leg, heel, and ankle. It separates from the tibial nerve at the superior aspect of the popliteal fossa and courses laterally around the fibular head where it divides into the deep and superficial peroneal nerves.
Complications from the common peroneal nerve block are rare, especially when care is taken to avoid an intraneural injection. Severe pain on injection suggests the possibility of an intraneural injection, and the needle should be immediately repositioned.