A Cadaveric Case Report of an Anomalous Sural Nerve Course Through the Gastrocnemius

The sural nerve is a superficial sensory nerve of the posterior leg that innervates the lateral foot. Anatomical variations in its course are clinically relevant, as they may affect surgical procedures, nerve blocks, and the risk of iatrogenic injury. This case report describes a rare variant in which the sural nerve pierces between the two heads of the gastrocnemius muscle, a course infrequently reported in the literature and important for surgical awareness. During routine lower-extremity dissection by first-year medical students at William Carey College of Osteopathic Medicine, Hattiesburg, USA, a rare sural nerve variant was identified in a 72-year-old Caucasian female cadaver obtained from the University of South Alabama Anatomical Gift Program, with dementia listed as the cause of death. The right sural nerve pierced both the medial and lateral heads of the gastrocnemius muscle approximately 11.43 cm inferior to the center of the popliteal fossa, deviating from its typical superficial course. After traversing the muscle, the nerve continued normally along the posterior leg. Adjacent structures, including the popliteal artery, popliteal vein, and tibial nerve, were unremarkable. Intact muscle fibers and the absence of fibrosis support this finding as a benign anatomical variation. While sural nerve variations are well-documented, instances of the nerve piercing the gastrocnemius muscle are exceedingly rare. Damage to the sural nerve can result in sensory deficits affecting the lateral foot and lower leg, which may impair recovery and quality of life. Awareness of such variations is vital for clinicians to prevent inadvertent nerve injury during surgeries or nerve blocks.