Morphometric Study of Gracilis Muscle and its Role in Clinical Reconstruction

Anatomical and topographical features of the gracilis muscle of the thigh from the position of using it for autotransplantation

Autotransplantation of a free flap of the gracilis muscle is currently actively used in reconstructive surgery for persistent prosoplegia, injuries of the brachial plexus, for plastic closure of defects in the upper lip, and in the treatment of pelvic sepsis. This study provides important information about the anatomical features of the gracilis muscle and its neurovascular bundle, which are highly variable. The study of the anatomical and topographic features of this fine thigh muscle was carried out on a sectional study of 25 corpses of both sexes, 50 lower limbs. The present study demonstrates that the median value of the total length of m. Gracilis, the length of its muscular part, as well as the length of the tendon were 452.25 (439.7; 462.0); 225.3(208.1;239.0); 230.5 (213.0; 244.4) mm, respectively. The number of vascular pedicles included in m. Gracilis, ranged from 1 to 5. In 86% of the cases, the deep femoral artery formed the dominant vascular pedicle, and in 14% of cases, it was the medial circumflex artery. Small secondary vascular pedicles originated from the descending genicular artery or the anterior branch of the obturator arter: from the basin of the internal iliac artery. The length of the main feeding artery varied from 76 to 134 mm, the median value was 100.5(90;110) mm, and its diameter ranged from 1.4 to 2.1 mm (M = 1.9(1.8;2, 0) mm. The innervation of the fine muscle of the thigh was carried out by the anterior branch of the obturator nerve, which in 82% of the cases was represented by a single trunk; less often a loose type of structure was observed. The proper nerve was located at a distance of 108.5 (96; 117) mm from the origin of the muscle; its diameter was 2.1 (1.9; 2.2) mm. Knowledge of the topographic and anatomical relationships of the neurovascular bundle with the surrounding formations, variants of its individual anatomical variability are the key to successful reconstructive surgery.

Quantitative and Neurovascular Anatomy of the Growing Gracilis Muscle in the Human Fetuses

This study is intended to obtain the algebraic growth dynamics of the gracilis in fetuses and determine the variations of neurovascular pedicle(s) of the gracilis, to aid infant surgeries. Forty fetuses (19 males and 21 females) were included in the study. Gestational mean age of the fetuses was 22.40 ± 2.67 (range, 18-28) weeks. Numerical values were obtained using a digital caliper and a digital image analysis software. Linear functions for the surface area, width, anterior, and posterior margin lengths of the gracilis were calculated, respectively, as: y = -289.307 + 20.501 × age (weeks), y = -7.113 + 0.622 × age (weeks), y = -24.421 + 3.434 × age (weeks), and y = -24.397 + 3.314 × age (weeks). In addition, length and width of the gracilis tendon were calculated as y = -6.676 + 0.934 × age (weeks) and y = -0.732 + 0.074 × age (weeks), respectively. Parameters of the gracilis had no statistically significant difference regarding side and sex (P > 0.05). In all the specimens, the gracilis was innervated by the anterior branch of the obturator nerve. Blood supply of the gracilis was identified to be derived from 1 single artery in 38 sides of total 80 (47.5%), from 2 arteries in 36 (45%) and from 3 arteries in 6 (7.5%). In 74 sides (92.5%), the nerve was superficial to the main artery, whereas in 6 sides (7.5%), it was deeper. The data of the present study could be beneficial for surgeons in infant surgeries to treat conditions such as obstetrical brachial plexus paralysis, facial palsy, or anal incontinence. Linear functions can be utilized to better evaluate the growth course of the gracilis in fetuses and to predict the dimensions thereof. Additionally, comprehending the structure and recognizing the variations of the gracilis nerves and arteries can help to protect the neurovascular pedicle(s) of the gracilis during the operations.