INTRODUCTION
The gracilis muscle has a quite constant anatomy, which makes it very useful in clinical practice. That muscle is a relatively unimportant adductor muscle, subject to removal without noticeable lower limb functional loss. Therefore, surgeons often transplant the gracilis muscle with its nerves and blood vessels for substitution purposes(I,2).
Sainsbury and Wagget(3) described the only report of an absence of that muscle. Gonella’1 performed a study with 38 Brazilian corpses and did not find any variation in this constitution of the muscle.
NORMAL ANATOMY
The gracilis muscle is the most superficial muscle of the medial thigh group; it arises from a thin aponeurosis at the half of anterior aspect from the pubic bone and its inferior ramus. The belly runs vertically at the medial aspect of the thigh and, at the fourth or fifth distal end, turns into a tendon. This tendon runs deeply to the sartorius muscle at the medial aspect of the femoral medial condyle, crosses the knee joint and inserts on the superomedi-al aspect of the tibia(1,2).
ANATOMICAL VARIATION
The anatomical variation described was found in a corpse of a 53-year-old black male. The corpse was fixed in 10% formaline. The gracilis muscle from the right lower limb (figure 1’ presented an anterior head originated from an aponeurosis at the anterior aspect of the pubic body, immediately lower to the pubic tubercle, extending 1.5 cm distally and a posterior head, originatedfrom a posteriorly located aponeurosis extending 3.5 cm to the inferior pubic ramus. The posterior head had a similar origin to the classical description of the muscle. Both heads run vertically down in parallel through the medial aspect of the thigh and fused distally at about 9 cm above the knee joint, where they gave rise to one tendon that extended towards the medial aspect of the knee joint and deeply to the sartorius muscle. It inserted at the superomedial aspect of the tibial body. The gracilis muscle from the left lower limb (figures 1 and 2) presented only one belly, originated from the aponeurosis of the anterior aspect of the pubic bone, immediately lower to the pubic tubercle to the inferior ramus. The insertion was similar to the right gracilis.
REFERENCES
1. Gonella H.A.: Contribuição ao estudo anatômico do músculo grácil: anatomia, inervação, vascularização e território vascular. Rev Bras Ortop 22: 71-75, 1987.
2. Moore K.L.: Anatomia Orientada para Clínica. 3a ed. Rio de Janeiro, Guanabara Koogan, p. 353, 1994.
3. Sainsbury J.R.C., Wagget J.: An absent gracilis – A case report. Br J Clin Pract 38: 72, 1984.
* Study performed at the Human Anatomy Laboratory of Uningá, Maringá, PR, Brazil.
