Gracilis muscle

Gracilis muscle
The gracilis and nearby muscles
Gracilis labeled at center right.
Latin	musculus gracilis
Gray's	subject #128 471
Origin	ischiopubic ramus
Insertion	tibia (pes anserinus)
Artery	medial circumflex femoral artery
Nerve	anterior branch of obturator nerve
Actions	flexes and adducts hip, knee

The Gracilis (Latin: slender) is the most superficial muscle on the medial side of the thigh. It is thin and flattened, broad above, narrow and tapering below. It arises by a thin aponeurosis from the anterior margins of the lower half of the symphysis pubis and the upper half of the pubic arch.

The muscle's fibers run vertically downward, ending in a rounded tendon. This tendon passes behind the medial condyle of the femur, curves around the medial condyle of the tibia where it becomes flattened, and inserts into the upper part of the medial surface of the body of the tibia, below the condyle. As a result of this the muscle is a lower limb adductor. At its insertion the tendon is situated immediately above that of the semitendinosus muscle, and its upper edge is overlapped by the tendon of the sartorius muscle, which it joins to form the pes anserinus. The pes anserinus is separated from the medial collateral ligament of the knee-joint by a bursa.

A few of the fibers of the lower part of the tendon are prolonged into the deep fascia of the leg.

Microsurgery

The gracilis muscle is commonly used as a flap in microsurgery. According to the classification of Mathes and Nahai it presents a type II blood supply. This allows it to be transferred on its artery derived from the medial circumflex femoral artery. This artery enters the muscle about 10 cm from the pubic symphysis. At this point (or 1 cm proximal) the nerve also enters.

Gracilis muscle is widely used in reconstructive surgery, either as a pedicled flap or as a free microsurgical flap. Both pedicled and free flaps can be muscular or musculocutaneos (the so- called "composite flaps"). As a pedicled flap, gracilis muscle can be used in perineal and vaginal reconstruction, after oncological surgery, in the treatment of recurrent anovaginal and rectovaginal fistulas as well in the coverage of the neurovascular bundle after vascular surgery ^[1].

As a functioning pedicled flap the gracilis muscle can be transferred for the treatment of anal incontinence. This technique called graciloplasty was described in the 1950s by Pickrell and was revolutionized in the late 1980s by the introduction of chronic muscle electro-stimulation. The gracilis microsurgical free flap is commonly used in the reconstruction of upper and lower limbs, in breast reconstruction and, as a free functioning flap, to restore forearm function or in dynamic reconstruction of facial paralysis.Gracilis Muscles Clinical Role

Transplantation Sites

The muscle may be split to reduce bulk for facial reanimation, as well as to repair hand muscles. It can be used to fashion an external anal sphincter. ^[2]

Additional images

Right hip bone. External surface.	Structures surrounding right hip-joint.	Muscles of the iliac and anterior femoral regions.	Muscles of the gluteal and posterior femoral regions.
The left femoral triangle.	Nerves of the right lower extremity. Front view.

References

External links

• LUC grac
• -194314161 at GPnotebook
• SUNY Figs 12:02-07 - "Muscles of the anterior (extensor) compartment of the thigh."
• SUNY Figs 14:02-02 - "Muscles that form the superficial boundaries of the popliteal fossa."
• Cross section at UV pembody/body18b
• PTCentral
• Functional CT and surgical figures

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated.