Accessory head of the sartorius arising from the femoral sheath: an anatomical variant with its clinical implications.

purposeThe sartorius muscle is a strap muscle in the front of the thigh that contributes to movements of the hip and knee joints. Variation in the origin and insertion of this muscle is rare but clinically relevant. Although registered in historical catalogue and reference books, no case report presenting sartorius originating from femoral sheath with photographic documentation and analysis of clinical implications has been found in the indexed literature to the best of our knowledge.

methodsA 74-year-old male cadaver was dissected for routine educational purposes, during which an accessory head of the sartorius muscle was identified. Morphometric measurements were recorded using a flexible tape following standard fixation.

resultsThe accessory head arose from the anterior layer of the femoral sheath, 5 cm inferolateral to the pubic tubercle, measured 21 cm in length and 1.2 cm in width, descended along the medial border of the main sartorius muscle, and fused with it at the junction of the upper two-thirds and lower one-third of the thigh. It was innervated by a branch of the anterior division of the femoral nerve and received its arterial supply from a branch of the femoral artery. The contralateral limb showed no such variation.

conclusionThis accessory head may potentially cause neurovascular compression involving structures like femoral artery and/or saphenous nerve which may lead to diagnostic confusion. It may also cause difficulty or untoward complications during flap harvesting procedure. Recognition and proper documentation of sartorius muscle variants of this kind is important to avoid diagnostic and surgical challenges involving the femoral region.