Gracilis muscle: arterial and neural basis for subdivision

The gracilis muscle is commonly utilized by reconstructive surgeons in a variety of applications as a pedicled muscle or musculocutaneous flap, and as a free tissue transfer for soft-tissue coverage or as a functioning muscle transfer. The muscle anatomy has been well documented in the past. The aim of the present study was to study comprehensively the intramuscular neurovascular anatomy as it relates to segmental neurovascular functioning muscle transfer. The study was carried out in a series of 14 human cadavers. Each cadaver was injected with a lead oxide, gelatin, and water solution through the femoral arteries (200 ml per kilogram). The overall length of the musculotendinous unit was 44 +/- 2 cm, and the tendon comprised up to 6 +/- 2 cm of the length. The main arterial supply to the muscle entered 10 +/- 1 cm from the attachment to the body and inferior ramus of the pubis (diameter, 1.5-2.5 mm). The distal portion of the muscle was supplied by one to three small arterial branches of the superficial femoral artery. Venous drainage was noted to be through paired venae comitantes. The motor nerve arises from the obturator nerve and enters the muscle in association with the major vascular pedicle. The nerve then splits within the muscle and runs longitudinally in two or three major branches within the muscle parallel to the arterial branches and muscle fibers. The neurovascular anatomy of the gracilis muscle was found to be remarkably consistent from specimen to specimen, varying only in the length of the muscle and tendon, and the number of minor pedicles supplying the distal portion of the muscle. This study confirms the suitability of the gracilis for segmental functional muscle transfer.