Biometría del músculo grácil: pedículos vasculares e inervación en un grupo de individuos brasileños / Biometric characteristics of the gracilis muscle: vascular pedicles and innervation in a group of Brazilian individuals

El músculo grácil (MG) está ubicado en la cara medial del muslo, medial y posterior al aductor largo en su parte proximal. Se origina a nivel del pubis y se inserta en la cara medial de la tibia, en su parte superior. Como colgajo libre funcional ha sido uno de los injertos más utilizados en reconstrucciones diversas, tales como pene, perineo, vagina, pierna, plexo braquial, parálisis facial, lesiones rectales, entre otras. Basado en lo anterior, el objetivo de este estudio fue complementar la anatomía del MG tanto en sus dimensiones como en sus pedículos vasculares e inervación, estableciendo las relaciones biométricas existentes, contribuyendo a la anatomía quirúrgica, en su uso como injerto. Para ello, se utilizaron 30 miembros inferiores de 20 cadáveres de individuos adultos, brasileños, de sexo masculino, 14 derechos y 16 izquierdos; 17 fijados en formol y 13 en glicerina. Se dividió al muslo en 4 cuartiles enumerados de proximal a distal como C1,C2,C3 y C4. Se contabilizó el número de pedículos y se nombraron como pedículo principal (PP), pedículo menor 1 (Pm1), pedículo menor 2 (Pm2) y pedículo menor 3 (Pm3). La longitud media del GM fue de 42,25 cm ± 2,35 cm y su ancho promedio de 32,90 ± 4,86 mm. Con respecto a los pedículos vasculares se encontró un pedículo en 10/30 casos (33,3 %); un pedículo principal y uno menor en 10/30 (33,3 %); un pedículo principal y dos menores en 8/30 (26,7 %) y un pedículo principal y tres menores en 2/30 (6,7 %). Su inervación siempre procedió del ramo anterior del nervio obturador (RaNO). El punto motor se encontró a una distancia promedio de 7,94 mm proximal al ingreso del pedículo principal en el MG. Los registros biométricos están expresados en tablas. Los resultados obtenidos aportarán al conocimiento anatómico, pudiendo ser utilizados como soporte morfológico a los procedimientos quirúrgicos que involucren al músculo grácil.

The gracilis muscle (GM) is located in the medial aspect of the thigh, medial and posterior to the long adductor in its proximal part. It originates at the pubic level and is inserted in the medial face of the tibia, in its upper part. As a functional free flap, it has been one of the most co mmonly used grafts in various reconstructions, such as penis, perineum, vagina, leg, brachial plexus, facial paralysis, rectal lesions, among others. Based on the above, the objective of this study was to complement the anatomy of the GM both in its dimensions and in its vascular pedicles and innervation, establishing the existing biometric relationships, contributing to the surgical anatomy, in its use as a graft. For this, 30 lower limbs of 20 bodies of adult, Brazilian, male, 14 right and 16 left individuals were used; 17 fixed in formaldehyde and 13 in glycerin. The thigh was divided into 4 quartiles listed from proximal to distal such as C1, C2, C3 and C4. The number of pedicles was counted and they were named as principal pedicle (PP), minor pedicle 1 (mP1), minor pedicle 2 (mP2) and minor pedicle 3 (mP3). The average length of the GM was 42.25 cm ± 2.35 cm and its average width was 32.90 ± 4.86 mm. With respect to vascular pedicles, a pedicle was found in 10/30 cases (33.3 %); one PP and one mP in 10/30 (33.3 %); one PP and two mP in 8/30 (26.7 %) and one PP and three mP in 2/30 (6.7 %). Its innervation always came from the anterior branch of the obturator nerve (aBON). The motor point was found at an average distance of 7.94 mm proximal to the entry of the PP in the GM. Biometric records are expressed in tables. The results obtained will contribute to anatomical knowledge, and can be used as morphological support for surgical procedures that involve the GM.

Comparison between donor nerves to motorize the free functional gracilis muscle transfer for elbow flexion: Retrospective study of 38 consecutive cases in traumatic adult brachial plexus injuries.

PURPOSE: Elbow flexion deficit is a frequent problem in traumatic brachial plexus injuries and reestablishment of this function is the primary treatment goal. When management is delayed, or the initial acute approach fails, free functional transfer of the gracilis muscle for elbow flexion is the treatment of choice. In this report, the authors present the results of a comparison study on different donor nerves (spinal accessory and ulnar) in elbow flexion reconstruction with gracilis flap for traumatic adult brachial plexus injuries. METHODS: Retrospective analysis of patients with both total or partial traumatic brachial plexus injuries was carried out. Of the 38 patients enrolled, 37 were male (97.4%) with a mean age of 28.3 years. The mean follow-up period was 25 months. Postoperative function of the gracilis muscle flap was recorded and patients were divided into two groups according to donor nerve: spinal accessory nerve (SAN) (18 cases), and motor fascicles of the ulnar (ULNAR) (20 cases). RESULTS: Twenty-six cases obtained elbow flexion strength M3 or M4 (68.4%): 0 M0 (0.0%), 4 M1 (10.5%), 8 M2 (21.1%), 9 M3 (23.7%) and 17 M4 (44.7%). The mean interval to first recorded M3 muscular strength was 12.4 months. Functional elbow flexion strength (≥ M3) had the following distribution: SAN 83.3% (15/18) and ULNAR 55.0% (11/20) (p = .086). CONCLUSION: No statistical difference for final muscle strength was found between donor nerve groups.

Long-Term Outcomes of Free Gracilis Muscle Transfer for Smile Reanimation in Children.

OBJECTIVE: To evaluate long-term outcomes of free gracilis muscle transfer (FGMT) for smile reanimation on smile excursion, facial symmetry, and quality of life in a cohort of children with facial palsy. STUDY DESIGN: A retrospective analysis of 40 pediatric patients who underwent FGMT for facial palsy at the Massachusetts Eye and Ear Infirmary Facial Nerve Center was performed. Preoperative and postoperative photography and videography were used to quantify smile excursion and facial symmetry. Preoperative and postoperative quality of life was assessed with the Facial Clinimetric Evaluation (FaCE) survey, a validated, patient-based instrument for evaluating facial impairment and disability. RESULTS: Of the 40 patients who underwent FGMT for facial palsy, 38 patients had complete data including preoperative and postoperative photography and videography from 3 months to 10 years following surgery; 13 cases had >5 years of follow-up. FGMT resulted in significant improvements in smile excursion within several months, with continued improvements in smile excursion and symmetry demonstrated more than 5 years later. Fifteen patients completed preoperative and postoperative FaCE surveys, which demonstrated significant improvement in quality of life scores following FGMT. CONCLUSIONS: FGMT significantly improves smile, facial asymmetry, and quality of life for years after this surgery for facial palsy.

Facial reanimation surgery in Möbius syndrome: Experience from 76 cases from a tertiary referral hospital in Latin America.

INTRODUCTION: Möbius syndrome is defined as a combined congenital bilateral facial and abducens nerve palsies. The main goal of treatment is to provide facial reanimation by means of a dynamic surgical procedure. The microneurovascular transfer of a free muscle transplant is the procedure of choice for facial animation in a child with facial paralysis. OBSERVATION: Between January 2008 and January 2017, 124 patients with the syndrome have been approached at our institution. Distribution according to Möbius Syndrome classification presents as follows: Complete Möbius syndrome (n=88), Incomplete Möbius syndrome (n=28), Möbius-Like syndrome (n=8). Seventy-nine female and 45 male patients. Sixty-one percent have undergone a microsurgical procedure (n=76), in all of them, a free gracilis flap transfer was performed. DISCUSSION: Our proposed treatment protocol for complete Möbius syndrome is determined by the available donor nerves. We prefer to use the masseteric nerve as first choice, however, if this nerve is not available, then our second choice is the spinal accesory nerve. For this purpose, all patients have an electromyography performed preoperatively. Overall, dynamic facial reanimation obtained through the microvascular transfer of the gracilis muscle have proved to improve notoriously oral comissure excursion and speech intelligibility. CONCLUSION: The free gracilis flap transfer is a reproducible procedure for patients with Möbius syndrome. It is of utmost importance to select the best motor nerve possible, based on an individualized preoperative clinical and electromyographic evaluation. To our best knowledge, this is the largest series of patients with Möbius syndrome globally, treated at a single-institution.

Neurotization of free gracilis transfer with the brachialis branch of the musculocutaneous nerve to restore finger and thumb flexion in lower trunk brachial plexus injury: an anatomical study and case report.

OBJECTIVE: To investigate the feasibility of using free gracilis muscle transfer along with the brachialis muscle branch of the musculocutaneous nerve to restore finger and thumb flexion in lower trunk brachial plexus injury according to an anatomical study and a case report. METHODS: Thirty formalin-fixed upper extremities from 15 adult cadavers were used in this study. The distance from the point at which the brachialis muscle branch of the musculocutaneous nerve originates to the midpoint of the humeral condylar was measured, as well as the length, diameter, course and branch type of the brachialis muscle branch of the musculocutaneous nerve. An 18-year-old male who sustained an injury to the left brachial plexus underwent free gracilis transfer using the brachialis muscle branch of the musculocutaneous nerve as the donor nerve to restore finger and thumb flexion. Elbow flexion power and hand grip strength were recorded according to British Medical Research Council standards. Postoperative measures of the total active motion of the fingers were obtained monthly. RESULTS: The mean length and diameter of the brachialis muscle branch of the musculocutaneous nerve were 52.66±6.45 and 1.39±0.09 mm, respectively, and three branching types were observed. For the patient, the first gracilis contraction occurred during the 4th month. A noticeable improvement was observed in digit flexion one year later; the muscle power was M4, and the total active motion of the fingers was 209°. CONCLUSIONS: Repairing injury to the lower trunk of the brachial plexus by transferring the brachialis muscle branch of the musculocutaneous nerve to the anterior branch of the obturator nerve using a tension-free direct suture is technically feasible, and the clinical outcome was satisfactory in a single surgical patient.

Neurotization of free gracilis transfer with the brachialis branch of the musculocutaneous nerve to restore finger and thumb flexion in lower trunk brachial plexus injury: an anatomical study and case report

OBJECTIVE: To investigate the feasibility of using free gracilis muscle transfer along with the brachialis muscle branch of the musculocutaneous nerve to restore finger and thumb flexion in lower trunk brachial plexus injury according to an anatomical study and a case report. METHODS: Thirty formalin-fixed upper extremities from 15 adult cadavers were used in this study. The distance from the point at which the brachialis muscle branch of the musculocutaneous nerve originates to the midpoint of the humeral condylar was measured, as well as the length, diameter, course and branch type of the brachialis muscle branch of the musculocutaneous nerve. An 18-year-old male who sustained an injury to the left brachial plexus underwent free gracilis transfer using the brachialis muscle branch of the musculocutaneous nerve as the donor nerve to restore finger and thumb flexion. Elbow flexion power and hand grip strength were recorded according to British Medical Research Council standards. Postoperative measures of the total active motion of the fingers were obtained monthly. RESULTS: The mean length and diameter of the brachialis muscle branch of the musculocutaneous nerve were 52.66±6.45 and 1.39±0.09 mm, respectively, and three branching types were observed. For the patient, the first gracilis contraction occurred during the 4th month. A noticeable improvement was observed in digit flexion one year later; the muscle power was M4, and the total active motion of the fingers was 209°. CONCLUSIONS: Repairing injury to the lower trunk of the brachial plexus by transferring the brachialis muscle branch of the musculocutaneous nerve to the anterior branch of the obturator nerve using a tension-free direct suture is technically feasible, and the clinical outcome was satisfactory in a single surgical patient.