When establishing the anterolateral portal for ankle arthroscopy, which of the following structures is most susceptible to injury?

Explanation:
The superficial peroneal nerve is at significant risk when placing the anterolateral portal in ankle arthroscopy. To minimize this risk, the portal should be made just lateral to the peroneus tertius tendon, and the skin should be incised superficially followed by blunt dissection using a mosquito hemostat. Transillumination can also help visualize the nerve branches. Reference: Mann's Surgery of the Foot and Ankle, 9th Edition.