Correlation Between Visual Inspection and Ultrasonography to Identify the Distal Branches of the Superficial Peroneal Nerve: A Cadaveric Study.

The anatomy of the superficial peroneal nerve (SPN) and, more precisely, of the distal branches of the SPN at the ankle has attracted interest owing to the possibility of injury when performing ankle arthroscopy. The anterolateral portal is one of the most commonly used portals in ankle arthroscopy, and the intermediate dorsal cutaneous nerve can easily be injured during portal placement. The purpose of the present study was to assess whether visual inspection and palpation of the cutaneous nerves at the ankle differed from examination with ultrasonography and whether the 2 examination techniques correlated with the anatomic location of the SPN, which was verified by cadaver dissection. First, visual examination and palpation was performed to identify the SPN, after which 12 cadaver legs from separate specimens were examined with ultrasonography to mark the course of the SPN. We then measured the distance between the nerve as identified with gross visualization/palpation and ultrasound examination, and compared these with the precise location determined by anatomic dissection. The use of ultrasonography to determine the course of the SPN was good or excellent in 11 of the 12 legs (91.7%) studied. In contrast, gross visualization/palpation was good or excellent in 4 legs (33.3%). Excellent agreement was observed between the ultrasound markings and the anatomic dissection results. However, the visual examination poorly identified the course and the anatomic variations of the nerve branches evidenced in the anatomic dissection. From these findings in cadaver specimens, ultrasound identification of the SPN and its branches is likely preferable to gross visualization/palpation before placement of the anterolateral arthroscopic portal to the ankle.