Anatomic variant of the gracilis muscle: a case report

Abstract

Gracilis is a medial thigh muscle that typically exhibits little anatomic variation. The muscle attaches proximally to the inferior pubic ramus. Unlike other adductors of the thigh, it inserts distally at the anteromedial aspect of the proximal tibia. The muscle and tendon are commonly used for reconstructive surgical procedures because of its ease of access as well as its consistent and abundant blood supply. Here we report a case of a unique unilateral anatomical variation in the gracilis muscle from an 84‐year‐old male cadaver. Variation in the distal attachment of the gracilis muscle was observed on the right side during routine dissection of the medial and posterior thigh compartments. Subsequent dissection determined innervation and muscular attachments. The skin and fascia lata were dissected to expose the medial thigh muscles, including the gracilis muscle. The following aspects were evaluated: (a) the origin and insertion of the muscle, (b) the measurements for the lengths and weights for the gracilis, semimembranosus, and semitendinosus muscles from both limbs, and c) the distance of the arterial pedicles from origin at the ischiopubic ramus for the gracilis muscles. Results showed the variant gracilis muscle inserted into the distal aspect of the semimembranosus and semitendinosus muscle bellies. As a result, the pes anserinus only contained tendons from the semitendinosus and sartorius muscles. The variant muscle was shorter and weighed less than the contralateral gracilis muscle. Two arterial pedicles inserted into the variant gracilis muscle belly as opposed to four on the contralateral side, suggesting reduced blood supply to the variant muscle. This report describes the details of the variation and its clinical significance in reconstructive surgery.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.