Topographic and histologic characteristics of the sural nerve for use in nerve grafting

The sural nerve (SN) is a sensory nerve supplying the skin of the lateral and posterior parts of the inferior third of the calf and the lateral side of the foot and is easy to harvest because of its location posterior and superior to the tip of the lateral malleolus. Seventy-one lower limbs from 42 Korean cadavers were dissected to describe the joining type and level of perforated the fascia of the SN. The segments of sural nerve were stained and measured. The communication and joining patterns of the SN formed by the medial sural cutaneous nerve and the communicating branch of the lateral sural cutaneous nerve could be divided into five types. The region where the medial sural cutaneous nerve and the communicating branch of the lateral sural cutaneous nerve join together was observed in 52 cases with this found in the lower two fifths of the calf in 28 (53.8%) of the specimens. The mean number of fascicles was 8.1 (range, 2-12) at the lower calf and 5.8 (range, 1-11) at the middle calf before where the medial sural cutaneous nerve and the communicating branch of the lateral sural cutaneous nerve joined. The mean total areas of the fascicles were 0.55 mm(2) and 0.43 mm(2) in the lower and middle calf, respectively. This study demonstrates that the anatomy of the SN affects its harvesting for use in nerve grafts with the reported results providing a useful reference for SN grafting procedures.