Review Question - QID 215518

During ankle arthroscopy, the superficial peroneal nerve (SPN) is the most commonly injured nerve. In the proximal leg, the SPN branches from the common peroneal nerve and runs in the lateral compartment where it provides motor branches to peroneus longus and brevis. Injury to the SPN occurs during establishment of the anterolateral portal.

Ankle arthroscopy is a useful procedure to treat a variety of ankle pathologies, including ankle impingement. However, during establishment of the portals, multiple neurovascular structures are at risk of injury. Common injury patterns include the following: saphenous nerve and vein with anteromedial portal, dorsalis pedis artery and deep peroneal nerve with anterocentral portal, sural nerve and short saphenous vein with posterolateral portal, and posterior tibial artery with posteromedial portal placement.

Ferkel et al. retrospectively reviewed the incidence of neurologic complications associated with ankle arthroscopy in 612 patients. They found neurological complications occurred in approximately 4% of patients during portal placement. They concluded the superficial peroneal nerve was the most commonly injured nerve during ankle arthroscopy.

Ferkel et al. performed a follow-up retrospective review of complications associated with ankle arthroscopy. They found the overall complication rate was 9%, and neurologic injury was the most common complication. They concluded that awareness of neurologic injury, and careful dissection during portal placement using the "nick and spread" technique may reduce complications.

Illustration A demonstrates the location of portal sites, and structures at risk, during ankle arthroscopy.

Incorrect Answers:
Answer 1: Deep peroneal nerve injury is rare during ankle arthroscopy. Injury to the nerve at this level would result in motor loss to the EDB and EHB muscles, as well as sensory deficit in the first web space.
Answer 2: The lateral dorsal cutaneous nerve of the foot is a terminal branch of the sural nerve, not SPN.
Answer 3: The medial plantar branch of the tibial nerve provides motor innervation to abductor hallucis and flexor hallucis brevis.
Answer 5: Saphenous nerve injury is not as common as SPN injury.