Unusual branch of the saphenous nerve to the sartorius muscle in a female cadaver.

Purpose: The saphenous nerve is a predominantly sensory nerve. It is the longest nerve of the body which supplies the skin of the medial side of the leg and foot as far as the ball of the great toe. We present here an unusual motor branch of the saphenous nerve to the sartorius muscle.

Method: Institutional guidelines for use of human cadaver were followed. Routine dissection of the lower limbs for undergraduate medical teaching was performed in a 67 years old female cadaver employing standard methods. Relevant gross features of the variations were photographed. H&E staining of relevant structure was done and photomicrographed.

Results: The unusual motor branch to Sartorius was observed in the right thigh. The branch was given off in the lower third of the thigh after the saphenous nerve exited the adductor canal. The branch was distinctly seen entering the substance of the sartorius. The structure was confirmed to be a peripheral nerve by histological examination. The saphenous nerve then descended between the sartorius and gracilis tendons, pierced the fascia lata and became cutaneous.

Conclusion: The motor branch to the sartorius muscle is a very rare branch whose knowledge is important for clinicians as it can get damaged during arthroscopy and other knee surgery or during adductor canal block.