Maurício Ferreira Caetano

ESTUDIO ANATÓMICO DE LAS INSERCIONES DE LOS MÚSCULOS EXTENSORES RADIALES LARGO Y CORTO DEL CARPO

En el analisis de los tendones de los musculos extensores radiales largo y corto del carpo, basados en la diseccion anatomica de 60 miembros superiores de cadaveres adultos de raza blanca y sexo masculino, registramos que las variaciones anatomicas no son muy frecuentes. La presencia de tendones accesorios ocurrio en apenas 3 manos disecadas, todas del musculo extensor radial largo del carpo. La presencia de vinculos tendinosos uniendo los tendones, fue registrada en 17 piezas. La presencia de un tendon intermedio uniendo los dos tendones, fue verificada en 4 piezas. La insercion del tendon del musculo extensor radial largo del carpo ocurrio, invariablemente, en el lado radial de la base del segundo metacarpiano y del musculo extensor radial corto en el lado radial de la base del tercer metacarpiano. Basados en nuestras disecciones podemos afirmar que la conformacion anatomica normal de los musculos extensores radiales largo y corto del carpo, es la presencia de un cuerpo muscular y un tendon de cada uno de los musculos extensores radiales que son cubiertos por los musculos abdutor largo y extensor corto; pasan por el segundo compartimiento dorsal del puno y se insertan, el musculo extensor radial largo en el lado radial de la base del segundo metacarpiano y el musculo extensor radial corto en el lado radial de la base del tercer metacarpiano, invariablemente

GANTZER MUSCLE. AN ANATOMICAL STUDY

OBJECTIVE: The relationship of Gantzer muscle to the median and anterior interosseous nerve is debated. METHODS: Ìn an anatomical study with 80 limbs from 40 cadavers the incidence, origin, insertion, nerve supply and relations of Gantzer muscle have been documented. RESULTS: The muscle was found in 54 forearms (68% of limbs) and was supplied by the anterior interosseous nerve. It arose from the deep surface of the flexor digitorum superficialis muscle, (42 limbs), coronoid process (eight limbs) and medial epicondyle (seven limbs). Its insertion was to the ulnar part of flexor pollicis longus muscle. The Gantzer muscle always lay posterior to both the median and anterior interosseous nerve. CONCLUSION: The Gantzer muscle may contribute to the median nerve and anterior interosseous nerve compression. The muscle was found in 68% of limbs and should be considered a normal anatomical pattern rather than an anatomical variation. Level of Evidence IV, Case Series .

Estudo anatômico das inserções distais do tendão extensor longo do polegar

Registramos pelo presente estudo que o musculo (ELP) e seu tendao apresentaram poucas variacoes anatomicas. Nao registramos a presenca de tendoes acessorios e nem a ausencia desse musculo ou de seu tendao. Verificamos em todas as preparacoes a passagem do tendao pelo terceiro compartimento osteofibroso, cruzando sobre os extensor radial curto (ERCC) e longo (ERLC) do carpo e dirigindo-se ao polegar. A alteracao no trajeto tendinoso, desviando-se no sentido radial foi verificada em uma das preparacoes (1,6%). A duplicacao parcial do tendao proximal a articulacao metacarpofalângica (AMFP) foi verificada em 3 observacoes (4,8%), sendo 1 bilateral, e distal a articulacao em 5 (8,3%), 2 bilateralmente. A insercao ossea na base da falange distal (BFD) foi encontrada em todas as observacoes. Durante sua passagem pela articulacao metacarpofalângica, registramos sua insercao na capsula articular em 14 observacoes (23,3%), porem nao registramos a insercao ossea nesse local. O padrao mais comum em relacao ao musculo ELP foi a presenca constante de 1 tendao, passando pelo terceiro compartimento osteofibroso dorsal do punho com insercao ossea na base da falange distal do polegar.

Clinical repercussions of Martin-Gruber anastomosis: anatomical study

Objective The main objective of this study was to describe Martin-Gruber anastomosis anatomically and to recognize its clinical repercussions. Method 100 forearms of 50 adult cadavers were dissected in an anatomy laboratory. The dissection was performed by means of a midline incision along the entire forearm and the lower third of the upper arm. Two flaps including skin and subcutaneous tissue were folded back on the radial and ulnar sides, respectively. Results Nerve communication between the median and ulnar nerves in the forearm (Martin-Gruber anastomosis) was found in 27 forearms. The anastomosis was classified into six types: type I: anastomosis between the anterior interosseous nerve and the ulnar nerve (n = 9); type II: anastomosis between the anterior interosseous nerve and the ulnar nerve at two points (double anastomosis) (n = 2); type III: anastomosis between the median nerve and the ulnar nerve (n = 4); type IV: anastomosis between branches of the median nerve and ulnar nerve heading toward the flexor digitorum profundus muscle of the fingers; these fascicles form a loop with distal convexity (n = 5); type V: intramuscular anastomosis (n = 5); and type VI: anastomosis between a branch of the median nerve to the flexor digitorum superficialis muscle and the ulnar nerve (n = 2). Conclusion Knowledge of the anatomical variations relating to the innervation of the hand has great importance, especially with regard to physical examination, diagnosis, prognosis and surgical treatment. If these variations are not given due regard, errors and other consequences will be inevitable.

INTRAMUSCULAR MARTIN-GRUBER ANASTOMOSIS

Objective : This paper reports the incidence, origin, course and anatomical relationships of intramuscular Martin-Gruber anastomosis. Methods : Anatomical dissection of 100 limbs from 50 adults cadavers was performed. The intramuscular Martin-Gruber anastomosis was found in five forearms, three in the right and two in the left side, one was bilateral. All communication were located between the anterior interosseous nerve and the ulnar nerve. Conclusion : The purpose of intramuscular Martin-Gruber anastomosis, which we found in 5% of dissected limbs, is to supply the flexor digitorum profundus muscle and it is unlikely to have any influence on the innervation of the intrinsic muscles of the hand. Level of Evidence IV, Cases Series.

ANATOMIC STUDY OF THE NERVOUS COMMUNICATION BETWEEN THE MEDIAN AND MUSCULOUCUTANEOUS NERVE

ABSTRACT Objective: The aim of this study was to analyze the incidence of nerve communication between the musculocutaneous and median nerve. Methods: Anatomical dissection of 40 limbs from 20 fetal cadavers was performed at the Laboratory of Anatomy, Faculdade de Ciências Médicas e da Saúde da Pontifícia Universidade Católica de São Paulo. Results: A communicating branch was found in 10 upper limbs. In nine limbs there was a musculocutaneous-median anastomosis (type I); and in one limb there was a median-musculocutaneous anastomosis (type II). Conclusion: It is very important to know these anatomical variations, especially when considering clinical examination, diagnostic, prognostic and surgical treatment. Level of Evidence IV, Case Series.

Anastomose de Riché‐Cannieu: estrutura, função e significância clínica

Objective  To define the anatomy pattern and the incidence of Riché-Cannieu anastomosis, that is, median and ulnar communication in the palmar aspect of the hand. Materials Methods  A total of 80 anatomical dissections were performed on 60 hands of 30 cadavers from 1979 to 1982, and on 20 hands from 2012 to 2015. All of these procedures were performed at the Department of Anatomy of our institution. The incidence of Riché-Cannieu anastomosis and the innervation of the thenar muscles were studied. Results  Riché-Cannieu anastomosis was identified in every dissected hand (100%). The extramuscular Riché-Cannieu anastomosis was recorded in 57 hands, and the intramuscular, in 19 hands. The association of extra- and intramuscular Riché-Cannieu anastomoses occurred in four hands. The ulnar component always originated from the deep branch. The anastomotic branch arising from the median nerve originated from the motor thenar branch (recurrent branch) of the median nerve in most of the observations. The median-ulnar double innervation only to the deep head of the flexor pollicis brevis was identified in 29 of 80 hands. The double innervation only of the superficial head of the flexor pollicis brevis was found in 13 hands. In 12 hands, the deep head of the flexor pollicis brevis was absent. The double innervation of the superficial and deep heads of the flexor pollicis brevis occurred in 14 hands. The oblique head of the adductor pollicis received double innervation in 12 hands. The deep head of the flexor pollicis brevis and the oblique head of adductor pollicis were doubly-innervated in nine hands. The transverse head of the adductor pollicis received double innervation in two hands. Double innervation of the deep head of the flexor pollicis brevis and the transverse head of the adductor pollicis were found in one hand. Conclusion  According to the present study, Riché-Cannieu anastomosis should be considered a normal anatomical neural connection, not an anatomical variation. Knowledge of this anastomosis is essential because the presence of such neural communication may result in confusing clinical, surgical, and electromyographic findings in cases of median or ulnar damage or entrapment.

Anterior interosseous nerve: anatomical study and clinical implications

Objective The goal of this study was to describe anatomical variations and clinical implications of anterior interosseous nerve. In complete anterior interosseous nerve palsy, the patient is unable to flex the distal phalanx of the thumb and index finger; in incomplete anterior interosseous nerve palsy, there is less axonal damage, and either the thumb or the index finger are affected. Methods This study was based on the dissection of 50 limbs of 25 cadavers, 22 were male and three, female. Age ranged from 28 to 77 years, 14 were white and 11 were non-white; 18 were prepared by intra-arterial injection of a solution of 10% glycerol and formaldehyde, and seven were freshly dissected cadavers. Results The anterior interosseous nerve arose from the median nerve, an average of 5.2 cm distal to the intercondylar line. In 29 limbs, it originated from the nerve fascicles of the posterior region of the median nerve and in 21 limbs, of the posterolateral fascicles. In 41 limbs, the anterior interosseous nerve positioned between the humeral and ulnar head of the pronator teres muscle. In two limbs, anterior interosseous nerve duplication was observed. In all members, it was observed that the anterior interosseous nerve arose from the median nerve proximal to the arch of the flexor digitorum superficialis muscle. In 24 limbs, the branches of the anterior interosseous nerve occurred proximal to the arch and in 26, distal to it. Conclusion The fibrous arches formed by the humeral and ulnar heads of the pronator teres muscle, the fibrous arch of the flexor digitorum superficialis muscle, and the Gantzer muscle (when hypertrophied and positioned anterior to the anterior interosseous nerve), can compress the nerve against deep structures, altering its normal course, by narrowing its space, causing alterations longus and flexor digitorum profundus muscles.

ARCADE OF FLEXOR DIGITORUM SUPERFICIALIS MUSCLE: ANATOMICAL STUDY AND CLINICAL IMPLICATIONS

ABSTRACT Objective: The arcade of the flexor digitorum superficialis muscle (FDS) is an anatomical structure which has not yet been widely studied and is a site of nerve compression. The aim of this study was to analyze the arcade of the FDS muscle and its relations with the median and anterior interosseous nerves through anatomic dissections. Method: Fifty arms from 25 adult cadavers (21 males and 4 females) were dissected; 18 were previously preserved in formalin and glycerin and 7 fresh specimens were dissected in the Laboratory of Anatomy. Results: The arcade of the superficial flexor muscle was identified in all dissected limbs. The radial and humeral heads were present in all specimens, and the ulnar head in 16 (32%). We identified two varieties of the arcade structure: a fibrous arcade in 32 specimens (64%), and a muscular arcade in 11 specimens (22%). In 4 specimens (8%) the arcade was very fine and so transparent that the nerve could be seen within the arcade. In 3 forearms the arcade was considered irregular because of discontinuity between the fibers that comprised this structure. Conclusion: The fibrous arcade of the FDS muscle may be a potential cause of nerve compression of the median and interosseous anterior nerves. Level of Evidence IV; Case series.

The arcade of Struthers: an anatomical study and clinical implications☆

Objective To determine the frequency and features of the arcade of Struthers, and to assess its clinical implication in ulnar nerve compression. Method Forty arms from 26 cadaver specimens were dissected in the Anatomy Laboratory of this institution. The extension of the arcade, distance from the medial epicondyle, and relation with ulnar nerve were recorded. Results The arcade of Struthers was identified in 40 dissected arms (100%). In 29 (72.5%) the ulnar nerve was covered by a muscular arcade, in nine (22.5%) by an aponeurotic arcade, and in two (5%) the arcade was beneath the ulnar nerve. The extension of the arcade ranged from 3.0 to 7.5 cm, and the distance from the medial epicondyle ranged from 2.5 to 7.0 cm. Conclusion The arcade of Struthers is a musculoaponeurotic canal that represents an important site of entrapment or compression of the ulnar nerve. The arcade, the intermuscular septum, and the internal brachial ligament should be released in patients submitted to ulnar nerve anterior transposition surgery.