Anatomical variations of the sural nerve in the leg: A fetal study

Background : Because of its clinical importance, numerous studies have been conducted worldwide documenting the anatomical variations of the sural nerve (SN). However, there is a paucity of literature from India concerning the anatomical variations of the SN in the leg. Aim : The aim of this study was to document the anatomical variations of the SN in the leg in Indian fetuses. Setting and Design : Anatomy department and an observational study. Materials and Methods : One hundred and two lower limbs from 51 fetuses of Indian origin (26 male and 25 female) with a crown-rump length ranging between 13 and 41 centimeters were dissected to expose the SN. The mode (Types A, B, C, D) and level of formation, bilateral symmetry, diameter of contributing nerves and presence of an intramuscular course were noted. Statistical Analysis : The relevant percentages were calculated and then tabulated. Results : When male and female fetuses were considered together, the SN was seen to be of Type A in 37.2%, Type B in 26.5%, Type C in 22.5% and Type D in 13.7% of the limbs. Bilateral symmetry of origin was noted in 60.8% of the fetuses. When the SN was formed by union of two or more nerves, the site of union was noted in the lower two-thirds of the leg in 95% of limbs. An intramuscular course of the SN or one of its contributors was seen in 16.7% of limbs. Conclusion : The present study showed differences in the anatomy of the SN compared to earlier studies, warranting further studies in the Indian population.