Variable patterns of the cutaneous innervation of the dorsum of the foot and its clinical implication

The superficial sensory nerves are at great risk for injury from lacerations and operative incisions. Precise knowledge regarding the course and distribution of sensory nerves over the dorsum of foot is important to avoid iatrogenic damage by surgeons who are planning the surgical intervention around the distal leg, ankle and foot. The objective of the study is to report the variation in the branching pattern and distribution of the cutaneous nerves over the dorsum of foot.

The study was carried out in 20 formalin fixed adult lower limbs in the Department of Anatomy, KMC Manipal, Manipal Academy of Higher Education, India. After the careful skin reflection, cutaneous nerves were traced.

Six out of twenty (30%) adult limbs had different pattern of cutaneous nerve innervation on the dorsum of foot. Among these five limbs (83.34%) had variation in the sural nerve innervation. In two limbs (33.33%) communications were found between superficial peroneal nerve and deep peroneal nerve. In one adult limb (16.67%) deep peroneal nerve supplied the second interdigital cleft. We grouped these into five types of variation pattern in the cutaneous innervation over dorsum of foot.

We observed five types of variation pattern, out of which variation II is not reported in the literature. The knowledge of these variations will help the surgeons to avoid iatrogenic damage of these nerves during surgeries involving distal leg, ankle and foot, open reduction and internal fixation of fracture, arthroscopy etc.