Variations in sural nerve formation pattern and distribution on the dorsum of the foot.

The sural nerve, a cutaneous nerve, is clinically important because it is frequently for nerve conduction testing, biopsy, and harvesting for nerve grafts. This nerve exhibits a wide variety of variation in formation, distribution on the dorsum of the foot, and so on, depending on the population observed. In this study, we examined the variation in the sural nerve in 110 Korean cadavers. Of these cadavers, 86.1% of the sural nerves corresponded to type A, where tibial and peroneal components were united to form the sural nerve. These two components most frequently united (65.9%) in the third quarter of the calf, and when the union position was expressed as a ratio to calf length, it corresponded to 0.408 in men and 0.346 in women, with a statistically significant difference. Due to this sexual dimorphism in addition to shorter calf length in females, the length of the sural nerve was shorter in females (male average length: 14.5 ± 4.8 cm; female average length: 11.4 ± 2.9 cm). In terms of distribution of the lateral dorsal cutaneous nerve, the distal continuation of the sural nerve on the dorsum of the foot, it showed variation in association with the superficial peroneal nerve. The innervation of the sural nerve extended most frequently up to the lateral two and a half toes, solely or in conjunction with the superficial peroneal nerve. Obtaining further information regarding sural nerve variation will be useful for various clinical procedures and interpretation of sural nerve conduction results. Clin. Anat. 30:525-532, 2017.