Ramo comunicante entre los nervios mediano y ulnar en el antebrazo humano / Communicanting branch between median and ulnar nerves in the human forearm

El ramo comunicante mediano-ulnar (RCMU) es la conexión que se origina del nervio mediano (NM) o alguno de sus ramos, para unirse al nervio ulnar (NU) en el antebrazo humano. Cuando este RCMU está presente, determina una prevalencia que oscila entre un 8 % y un 32 %, de tal manera los axones del NM se trasladen al NU, modificando la inervación habitual de los músculos de la mano. Nuestro objetivo fue determinar la prevalencia, biometría, topografía y relaciones anatómicas del RCMU. Adicionalmente, se estableció la coexistencia de otras conexiones entre los NM y NU en el antebrazo y la mano. Se realizó un estudio descriptivo, cuantitativo, no experimental y transeccional. Disecamos 30 antebrazos humanos de individuos adultos, pertenecientes al programa de donación cadavérica de la Pontificia Universidad Católicade Chile. Las muestras estaban fijadas en formalina y a 4 °C. El RCMU se presentó en 5 casos (17 %). De estos ramos, tres surgieron del nervio interóseo anterior (NIA) (60 %) y dos (40 %) del ramo que el NM aporta a los músculos superficiales del compartimiento anterior del antebrazo. Estos se clasificaron de acuerdo a la literatura, así el tipo Ic se presentó en tres casos (60 %), y el tipo Ia en dos (40 %). La longitud promedio del RCMU fue de 53,9 mm. El origen del RCMU se ubicó en el tercio proximal y la conexión de este con el NU se estableció en el tercio medio del antebrazo. En tres casos (60 %) se observó la coexistencia del RCMU y una conexión entre los ramos digitales palmares comunes. Estos hallazgos confirman que el RCMU mayoritariamente se extiende entre el nervio interóseo anterior y el NU, y su presencia podría modificar la distribución nerviosa de la mano.

SUMMARY: The median-ulnar communicating branch (MUCB) is the communication that originates from the median nerve (MN) or one of its branches, to join the ulnar nerve (UN) in the human forearm. With a prevalence that oscillates between 8% and 32%, when this MUCB is present, it establishes that axons from the MN move to the UN, modifying the normal innervation of the muscles of the hand. Our aim was to determine the prevalence, biometry and topography and anatomical relationships of the MUCB. Additionally, the coexistence of this MUCB with other connections between the MN and UN was established. A descriptive, quantitative, non experimental and transectional study was conducted. Thirty adult human forearms belonging to the cadaveric donation program of the Pontificia Universidad Católica de Chile were dissected. The samples were fixed in formalin and stored at 4 °C. The MUCB appeared in 5 cases (17%). Of these, three originated from the anterior interosseous nerve (60%) and two (40%) arose from the branch that the MN gives it to the superficial muscles of the anterior compartment of the forearm. These were classified according to the literature consulted, obtaining that Group Ic occurred in three cases (60%), and Group Ia in two (40%). The average MUCB length was 53.9 mm. The origin of the MUCB was on average 21% of the length of the forearm from the biepicondylar line. The connection of this MUCB with the UN was located on average at 44% from this line. In three cases (60%) the coexistence of the MUCB and a connection between the common palmar digital nerves was observed. These findings confirm that the RCMU is generally established between the anterior interosseous nerve of forearm and NU, and its presence could modify the nerve distribution of the hand.

Transient median nerve palsy following ultrasound-guided subscapularis plane block: a case report

Abstract The subscapularis plane block is an effective approach to anesthetize axillary and upper subscapular nerves. There have been no reports regarding brachial plexus paralysis as a potential complication to date. Described here is a case of median nerve palsy following ultrasound-guided subscapularis plane block for awake frozen shoulder manipulation that was performed on a 52-year-old female diagnosed with adhesive capsulitis. The patient could not flex digits two and three, and ipsilateral inner palm numbness occurred shortly after the block commenced, with complete resolution in the next two hours. The local anesthetics spillage towards brachial plexus with possible partial paralysis should always be expected after subscapularis plane block.

Síndromes compresivos del nervio mediano. Revisión y actualización de la bibliografía / Median nerve compression syndromes. Literature review and update

El nervio mediano desciende por el brazo y, en el codo, comienza a atravesar estructuras que pueden generar compresión, como el ligamento de Struthers, el lacertus fibrosus, el pronador redondo, el flexor superficial de los dedos. Finalmente, en la muñeca, se encuentra otro sitio de compresión producido por el ligamento transverso del carpo. Todas estas estructuras pueden provocar signos y síntomas de atrapamiento nervioso y favorecer el deterioro funcional del nervio. Nuestro objetivo es dar a conocer una actualización sobre estos sitios de atrapamiento del nervio mediano, y cómo realizar un diagnóstico preciso e indicar un trata-miento adecuado. Nivel de Evidencia: IV

The median nerve is a nervous structure that begins to cross structures at the level of the elbow that might cause compression. The Struthers ligament, lacertus fibrosus, pronator teres, and flexor digitorum superficialis are among them. Finally, the transverse carpal ligament creates another compression site in the wrist. All these structures can develop pathological signs and symptoms of nerve entrapment, which favors nerve functional degradation. Our objective is to provide an update on these median nerve entrap-ment sites, as well as information on how to establish an accurate diagnosis and provide adequate treatment. Level of Evidence: IV

Prevalence of Anatomical Variations in Patients with Carpal Tunnel Syndrome Undergoing Classical Open Carpal Tunnel Release / Prevalência de variações anatômicas encontradas em pacientes com síndrome do túnel do carpo submetidos a liberação cirúrgica por via aberta clássica

Abstract Objective To evaluate the prevalence of anatomical variations encountered in patients with carpal tunnel syndrome who underwent carpal tunnel classical open release. Methods A total of 115 patients with a high probability of clinical diagnosis for carpal tunnel syndrome and indication for surgical treatment were included. These patients underwent electroneuromyography and ultrasound for diagnostic confirmation. They underwent surgical treatment by carpal tunnel classical open release, in which a complete inventory of the surgical wound was performed in the search and visualization of anatomical variations intra- and extra-carpal tunnel. Results The total prevalence of anatomical variations intra- and extra-carpal tunnel found in this study was 63.5% (95% confidence interval [CI]: 54.5-72.4). The prevalence of the carpal transverse muscle was 57.4% (95% CI: 47.8-66.6%), of the bifid median nerve associated with the persistent median artery was 1.7% (95% CI: 0.0-4.2%), and the median bifid nerve associated with the persistent median artery and the transverse carpal muscle was 1.7% (95% CI: 0.0-4.2%). Conclusion The most prevalent extra-carpal tunnel anatomical variation was carpal transverse muscle. The most prevalent intra-carpal tunnel anatomical variation was median bifid nerve associated with the persistent median artery. The surgical finding of an extra-carpal tunnel anatomical variation, such as the transverse carpal muscle, may indicate the presence of other associated carpal intra tunnel anatomical variations, such as the bifid median nerve, persistent median artery, and anatomical variations of the recurrent median nerve branch.

Resumo Objetivo Avaliar a prevalência de variações anatômicas encontradas em pacientes com síndrome do túnel do carpo submetidos a liberação cirúrgica por via aberta clássica. Métodos Foram incluídos um total de 115 pacientes com alta probabilidade de diagnóstico clínico de síndrome do túnel do carpo, com indicação para o tratamento cirúrgico. Estes pacientes realizaram eletroneuromiografia e ultrassonografia para confirmação diagnóstica. Foram submetidos ao tratamento cirúrgico por via aberta clássica, no qual foi realizado um inventário completo da ferida operatória na busca e visualização de variações anatômicas intra e extra túnel do carpo. Resultados A prevalência total das variações anatômicas intra e extra túnel do carpo encontradas neste estudo foi de 63,5% (intervalo de confiança [IC]95%: 54,5-72,4%). A prevalência do músculo transverso do carpo foi de 57,4% (IC95%: 47,8-66,6%), do nervo mediano bífido associado à artéria mediana persistente foi de 1,7% (IC95%: 0,0-4,2%) e do nervo mediano bífido associado à artéria mediana persistente e ao músculo transverso do carpo foi de 1,7% (IC95%: 0,0-4,2%). Conclusão A variação anatômica extra túnel do carpo mais prevalente foi o músculo transverso do carpo e a variação anatômica intra túnel do carpo mais prevalente foi o nervo mediano bífido associado à artéria mediana persistente. O achado cirúrgico de uma variação anatômica extra túnel do carpo, como o músculo transverso do carpo, pode nos indicar a presença de outras variações anatômicas intra túnel do carpo associadas, como nervo mediano bífido, artéria mediana persistente e variações anatômicas do ramo recorrente do nervo mediano.

Clinical, electrophysiological, and ultrasound evaluation for early detection of musculoskeletal hand disorders and nerve entrapment in mobile phone users

ABSTRACT Introduction: Smartphone overuse may lead to musculoskeletal manifestations, such as carpal tunnel syndrome (CTS) and arthritis of hand joints, with an increased median nerve cross-sectional area (CSA). Objective: The aim of this study is the early detection of musculoskeletal hand disorders using ultrasound techniques, and to detect nerve entrapment using clinical evaluation, ultrasound, and electrophysiological studies, in university employees younger than 35 years using mobile phones. Function is assessed using the Michigan Hand Outcomes Questionnaire (MHQ). Materials and methods: Cross-sectional controlled study included 74 smartphone users classified into two groups according to a smartphone addiction scale (SAS), into high and low smart phone users, with 35 non-smartphone users with matched age and gender as a control group. A clinical assessment of nerve entrapment symptoms was performed, and the Michigan Hand Outcomes Questionnaire (MHQ), with a total score from 0 to100, was used to assess hand function. Electrodiagnostic studies of median and ulnar nerves were used to detect early nerve entrapment. Bilateral ultrasound was performed in order to assess the median nerve CSA and involvement of thumb and small hand joints. The data collected were analyzed using the SPSS program version 20. Results: CSAs of median nerves were significantly higher in the dominant hand of high smartphone users than in low and non-smartphone users (p < 0.001). There was a significant positive correlation between CSA and SAS (r = 0.45), visual analogue scale (VAS) (r = 0.61), and duration of smartphone use (r = 0.80), with negative correlation with MHQ (r = -0.63). Significant differences in were found in the electrophysiological studies of median and ulnar nerves. The mean ultrasound score for both hands was higher in the high smartphone users compared to low smartphone users (15.08 ± 4.17 vs. 6.46 ± 1.38, p < .001). Conclusions: There is increased median nerve CSAs among high smartphone users associated with prolongation of both sensory and motor latencies and slow conduction velocities. Caution should be exercised when using mobile phones, in order to minimize the risk of developing hand musculoskeletal disorders.

Superficial communication between ulnar and media nerves in the hand: an anatomical study / Comunicación superficial entre los nervios ulnar y mediano de la mano: un estudio anatómico

SUMMARY: The objective of this study was to characterize the communication between ulnar and the median nerve in the superficial palmar region from a sample of mestizo-raced population predominant in Latin America. The superficial palmar regions of 53 fresh cadaveric specimens were evaluated, whom of which underwent necropsy procedure at the Institute of Legal Medicine. Dissection was performed by planes until visualizing the presence of the Communicating Branch (CB) between the digital branches of the ulnar nerve (UN) and the median nerve (MN). Qualitative and morphometric evaluation of the CB was carried out. A CB were observed in 82/ 106 (77.4 %) of the cadaveric specimens studied, of which, 38/53 (71.7 %) were bilateral, 15/53 (28.3 %) unilateral; this being a statistically significant difference (p <0.002). Oblique trajectory of the CB between the fourth and third common digital nerve was observed in 70 (85.4 %) specimens, while the CB with transverse trajectory was found in 7 (8.5 %) regions and in a plexiform form in 5 (6.1 %) cases. The length of the CB was 20.2 ± 5.1 mm and the distances from the upper edge of the flexor retinaculum to the proximal and distal points of the CB were 25 ± 6 mm and 37.4 ± 8.3 mm respectively. The anatomical characteristics of the CB patterns, as well as the morphometric CB findings and their points of reference from the carpal flexor retinaculum, make it possible to delimit a safe area of surgical access in the first-fifth proximal of the palmar region, during the surgical approach of carpal tunnel syndrome.

RESUMEN: El objetivo de este estudio fue caracterizar la comunicación entre los nervios ulnar y mediano en la región palmar superficial a partir de una muestra de población de raza mestiza predominante en América Latina. Se evaluaron las regiones palmares superficiales de 53 especímenes cadavéricos frescos, los cuales fueron sometidos procedimiento de necropsia en el Instituto de Medicina Legal. La disección se realizó por planos hasta visualizar la presencia del ramo comunicante (RC) entre los ramos digitales palmares del nervio ulnar (NU) y del nervio mediano (NM). Se realizó evaluación cualitativa y morfométrica del RC, observándose RC en 82/106 (77,4 %) de los especímenes cadavéricos estudiados, de los cuales 38/53 (71,7 %) eran bilaterales, 15/53 (28,3 %) unilaterales; siendo esta una diferencia estadísticamente significativa (p <0,002). Se observó trayectoria oblicua del RC entre el cuarto y tercer nervio digital palmar común en 70 muestras (85,4 %), mientras que el RC con trayectoria transversal se encontró en 7 casos (8,5 %) y en forma plexiforme en 5 casos (6,1 %). La longitud del RC fue de 20,2 ± 5,1 mm y las distancias desde el margen superior del retináculo flexor hasta los puntos proximal y distal del RC fueron de 25 ± 6 mm y 37,4 ± 8,3 mm, respectivamente. Así, los hallazgos morfométricos del RC y sus puntos de referencia, desde el retináculo flexor, permiten delimitar una zona segura de acceso quirúrgico en el primer-quinto proximal de la región palmar, durante el abordaje quirúrgico del síndrome del túnel carpiano.

Lesión del nervio mediano por cuerpo extraño metálico en un adulto joven / Lesion of the median nerve due to metallic strange body in a young adult

Se describe el caso clínico de un paciente de 36 años de edad, quien acudió a la consulta de Ortopedia y Traumatología del Hospital General Docente Dr. Juan Bruno Zayas Alfonso de Santiago de Cuba, con un alambrón oxidado, encarnado en la cara palmar de la muñeca derecha, con parestesias en la zona de inervación del nervio mediano. La radiografía reveló que dentro de las estructuras de la muñeca había 10 cm del alambrón, con la porción distal doblada en forma de gancho, por lo cual se le realizó intervención quirúrgica de urgencia. Se utilizó anestesia regional, sedación e isquemia y se extrajo el cuerpo extraño en sentido contrario a la curvatura que presentaba. Luego de pasar el efecto anestésico persistían las parestesias en el pulpejo del índice, que desaparecieron completamente a los 4 meses del accidente. Se incorporó a sus labores habituales a los 2 meses de operado.

The case report of a 36 years patient is described. He went to the Orthopedics and Traumatology Service of Dr. Juan Bruno Zayas Alfonso Teaching General Hospital in Santiago de Cuba, with a rusty big wire, ingrowing in the right wrist palmar face, with paresthesias in the innervation area of the median nerve. The x-ray revealed that inside the wrist structures there was 10 cm of the big wire, with the distal portion bent in hook form, reason why an emergency surgical intervention was carried out. Regional anesthesia, sedation and ischemia were used and the strange body was removed in sense contrary to the bend that presented. After the anesthetic effect eased the paresthesias of the index finger tip persisted that disappeared completely 4 months after the accident. He went back to his usual works 2 months after the operation.

Two cases of variations of musculocutaneous nerve communication with the median nerve / Dos casos de variaciones de la comunicación del nervio musculocutáneo con el nervio mediano

SUMMARY: To know the nerve variations of brachial plexus and its branches is very important in the management of upper limb nerve injuries. Variations of the brachial plexus are not uncommon, but types of variations are diverse. The unusual communication branches between the musculocutaneous nerve (MCN) and the median nerve (MN) in course were found during routine dissection on the two different left arms of formalin fixed male cadavers. Depending on the position related to the coracobrachial muscle (CBM), one MCN pierced the CBM, the other did not in the two cases. The branches of MCN emerged interior to the coracoid process to innervate the CBM. The present case reports of anatomical variations of nerves can help to manage nerve injuries and plan surgical approaches during surgical procedures.

RESUMEN: Conocer las variaciones nerviosas del plexo braquial y sus ramas es muy importante en el tratamiento de las lesiones nerviosas de los miembros superiores. Las variaciones del plexo braquial no son infrecuentes, sin embargo los tipos de variaciones son diversos. Los ramos inusuales de comunicación entre el nervio musculocutáneo (NMC) y el nervio mediano (NM) en curso fueron descubiertos durante la disección de rutina en dos miembros superiores izquierdos de dos cadáveres de sexo masculino fijados con formalina. Un NMC atravesó el MCB, otro no lo hizo en los dos casos. Los ramos de NMC emergieron a nivel del proceso coracoideo para inervar el MCB. Los presentes informes de casos de variaciones anatómicas de los nervios pueden ayudar a tratar las lesiones nerviosas y planificar los abordajes quirúrgicos durante los procedimientos quirúrgicos.

Ulnar two-point discrimination following endoscopic carpal tunnel release / La liberación endoscópica del túnel carpiano y la prueba de discriminación de dos puntos del nervio cubital

Abstract Carpal tunnel syndrome is median nerve symptomatic compression at the level of the wrist, characterized by increased pressure within the carpal tunnel and decreased nerve function at the level. Carpal tunnel release decreases pressure in Guyon's canal, via open techniques, with symptom and two-point discrimination improvement in the ulnar nerve distribution. We hypothesize that endoscopic carpal tunnel release improves two-point discrimination in the ulnar nerve distribution as well. This study includes 143 patients who underwent endoscopic carpal tunnel release between April 2016 to June 2019 in a single, community-based teaching hospital. A comprehensive retrospective chart review was performed on patient demographics, preand post-operative two-point discrimination test results, and complications. The effects of sex, age, and diabetes mellitus in the ulnar and median nerve territories with two-point discrimination tests were analyzed. As well as the differences in two-point discrimination among patient's based on their smoking status. There were significant post operative improvements in both the median (7.7 vs 4.4 mm, p < 0.001) and ulnar (5.7 vs 4.1 mm, p < 0.001) nerve territories. Smoking status, sex, age and diabetes did not significantly affect two-point discrimination outcomes. In conclusion the endoscopic release of the transverse carpal ligament decompresses the carpal tunnel and Guyon's canal, demonstrating improvement in two-point discrimination in both the ulnar and median nerve distributions.

Resumen El síndrome de túnel carpiano es la compresión sintomática del nervio mediano al nivel de la muñeca. Se caracteriza por un aumento de presión dentro del túnel y una disminución de la función del nervio a ese nivel. La liberación del túnel carpiano descomprime el canal de Guyon, con mejoría sintomática y en la prueba de discriminación de dos puntos en la distribución del nervio cubital. Hipotetizamos que la liberación endoscópica mejora de la misma manera en la distribución del nervio cubital. Este trabajo incluye 143 pacientes que tuvieron liberación endoscópica del túnel carpiano entre abril del 2016 y junio del 2019 en un hospital Universitario de la comunidad. Se evaluaron retrospectivamente las historias clínicas para los datos demográficos, los resultados pre y post quirúrgicos en la prueba de discriminación de dos puntos y complicaciones. Se analizaron los efectos del sexo, edad, tabaco y diabetes en los resultados de la prueba de discriminación de dos puntos para los nervios cubital y mediano. Hubo mejoría significativa post quirúrgica en la prueba de discriminación de dos puntos para los nervios mediano (7.7 vs 4.4 mm, p < 0.001) y cubital (5.7 vs 4.1 mm, p < 0.001). Fumadores, sexo, edad, y diabetes no afectaron de forma significativa. Concluimos que la liberación endoscópica del ligamento transverso del carpo descomprime el túnel carpiano y el canal de Guyon con mejoría en la prueba de discriminación de dos puntos para los nervios cubital y mediano.

Anastomosis Patterns between the Median and Ulnar Nerves in the Upper Limbs

There are four types of anastomoses between themedian and ulnar nerves in the upper limbs. It consists of crossings of axons that produce changes in the innervation of the upper limbs, mainly in the intrinsic muscles of the hand. The forearm has two anatomical changes ­ Martin-Gruber: branch originating close to the median nerve joining distally to the ulnar nerve; and Marinacci: branch originating close to the ulnar nerve and distally joining the median nerve. The hand also has two types of anastomoses, which are more common, and sometimes considered a normal anatomical pattern ­ Berrettini: Connection between the common digital nerves of the ulnar and median nerves; and Riche-Cannieu: anastomosis between the recurrent branch of the median nerve and the deep branch of the ulnar nerve. Due to these connection patterns, musculoskeletal disorders and neuropathies can be misinterpreted, and nerve injuries during surgery may occur, without the knowledge of these anastomoses. Therefore, knowledge of them is essential for the clinical practice. The purpose of the present review is to provide important information about each type of anastomosis of the median and ulnar nerves in the forearm and hand.

Onset of Trigger Finger after Carpal Tunnel Syndrome Surgery: Assessment of Open and Endoscopic Techniques / Frequência do aparecimento de dedo em gatilho no pós-operatório da síndrome do túnel do carpo em duas técnicas cirúrgicas: Aberta e endoscópica

Abstract Objective The present study aimed to determine the frequency of trigger finger (TF) onset after surgery for carpal tunnel syndrome (CTS) using an open (OT) or an endoscopic technique (ET). As a secondary endpoint, the present study also compared paresthesia remission and residual pain rates in patients submitted to both techniques. Methods Trigger finger onset and remission rates of paresthesia and pain at the median nerve territory was verified prospectively in a series of adult patients submitted to an OT procedure (n = 34). These findings were compared with a retrospective cohort submitted to ET (n = 33) by the same surgical team. Patients were evaluated with a structured questionnaire in a return visit at least 6 months after surgery. Results Sixty-seven patients were evaluated. There was no difference regarding trigger finger onset (OT, 26.5% versus ET, 27.3%; p = 0.94) and pain (OT, 76.5% versus ET, 84.8%; p = 0.38). Patients submitted to OT had fewer paresthesia complaints compared with those operated using ET (OT, 5.9% versus ET, 24.2%; p = 0.03). Conclusions In our series, the surgical technique did not influence trigger finger onset and residual pain rates. Patients submitted to OT had less complaints of residual postoperative paresthesia.

Resumo Objetivo Determinar a frequência do aparecimento de dedo em gatilho (DG) no pós-operatório da síndrome do túnel do carpo (STC) em duas técnicas: aberta (TA) e endoscópica (TE). Como desfecho secundário, comparar as taxas de remissão da parestesia e dor residual entre as duas técnicas. Métodos De forma prospectiva, verificamos o aparecimento de dedo em gatilho e taxa de remissão da parestesia e dor no território do nervo mediano em série de pacientes adultos operados pela TA (n = 34). Comparamos com coorte retrospectiva operada pela TE (n = 33), pela mesma equipe de cirurgiões. A avaliação dos pacientes ocorreu por meio de questionário estruturado em consulta de retorno, com mínimo de 6 meses de pós-operatório. Resultados Sessenta e sete pacientes foram avaliados. Não houve diferença quanto ao aparecimento de dedo em gatilho (TA, 26,5% versus TE, 27,3%; p = 0,94) e dor (TA, 76,5% versus TE, 84.8%; p = 0,38). Os pacientes operados pela TA apresentaram menos queixas de parestesia do que os operados pela TE (TA 5,9% versus TE 24,2%; p = 0,03). Conclusões Em nossa série, a técnica cirúrgica não influenciou o aparecimento de dedos em gatilho e dor residual. Os pacientes operados pela técnica aberta apresentaram menos queixa de parestesia residual pós-operatória.

An accessory abductor digiti minimi as possible risk factor of the median and ulnar nerves compression / Músculo abductor digiti minimi accesorio como posible factor de riesgo de la compresión de los nervios mediano y ulnar

SUMMARY: During routine dissection of a left upper limb of a 68-year-old male human cadaver, an unusual muscle was observed originating from the radius and flexor retinaculum, and continued in the hypothenar region with the muscle belly of the abductor digiti minimi. We checked that it was an accessory abductor digiti minimi (ADM). Its muscular belly was in close relation to the median and ulnar nerves. We review the literature regarding such muscle variations and discuss the potential for compression of the median and ulnar nerves. Although the accessory ADM is usually asymptomatic and only rarely results in nerve compression, it should be taken into account by surgeons when establishing a differential diagnosis in the compression neuropathies of the median and ulnar nerves. An ultrasound scanning can help establish the differential diagnosis.

RESUMEN: Durante la disección de rutina de un miembro superior izquierdo de un cadáver humano masculino de 68 años, se observó un músculo inusual que se originaba en el radio y el retináculo flexor del carpo, y continuuaba en la región hipotenar con el vientre muscular del abductor digiti minimi manus. Verificamos que se trataba del músculo abductor digiti minimi accessorius (ADMA). Su vientre muscular se encontraba en estrecha relación con los nervios mediano y ulnar. Revisamos la literatura sobre variaciones musculares y discutimos la potencial compresión de los nervios mediano y ulnar. Aunque el ADMA suele ser asintomático y rara vez produce compresión nerviosa, los cirujanos deben tenerlo en cuenta al establecer un diagnóstico diferencial en las neuropatías de compresión de los nervios mediano y ulnar. Una ecografía puede ayudar a establecer el diagnóstico diferencial.

Retinaculotomía endoscópica de doble portal en el síndrome del túnel carpiano / Dual-portal endoscopic release in carpal tunnel syndrome

NiResumen Objetivo: Evaluar los resultados de la retinaculotomía endoscópica para tratar el síndrome del túnel carpiano mediante la técnica de doble portal de Chow, entre enero de 2006 y diciembre de 2015. Materiales y Métodos: Estudio de 179 pacientes (edad promedio 48.2 años [rango 32-68]), con 217 casos de síndrome del túnel carpiano idiopático y un seguimiento promedio de 97.9 meses. Los pacientes eran 145 mujeres (81%) (31 bilaterales) y 34 hombres (19%) (7 bilaterales) y fueron evaluados con la Symptom Severity Scale (SSS) y la Functional Status Scale (FSS) del Boston Carpal Tunnel Questionnaire (BCTQ). Resultados: El puntaje medio de la SSS-BCTQ fue de 3,20 + 0,26 antes de la cirugía, mejoró a 1,30 + 0,12 a los 6 meses y se mantuvo en 1,25 + 0,11 a largo plazo. El puntaje medio de la FSS-BCTQ fue de 2,57 + 0,29 antes de la cirugía, mejoró a 1,28 + 0,18 a los 6 meses y se mantuvo en 1,20 + 0,09 a largo plazo. Hubo 7 casos (3,2%) de neuropraxia posquirúrgica transitoria. No hubo conversiones a técnica abierta. Conclusión: La liberación endoscópica del túnel carpiano con la técnica de Chow es un método quirúrgico eficaz y seguro para tratar el síndrome del túnel carpiano idiopático. Nivel de Evidencia; III

Objective: To evaluate the outcomes of endoscopic release of the transverse carpal ligament (TCL) in carpal tunnel syndrome (CTS) using the Chow dual-portal technique between January 2006 and December 2015. Materials and Methods: Study population consisted of 217 cases of idiopathic CTS, in 179 patients, 145 females (81%) (31 bilateral cases) and 34 males (19%) (7 bilateral cases), with an average age of 48.2 years (range, 32-68) and an average follow-up of 97.9 months. The symptom severity and functional evaluations were performed using the Boston Carpal Tunnel Questionnaire Symptoms Severity Scale (BCTQ-SSS) and the Functional Status Scale (BCTQ-FSS). Results: The average BCTQ-SSS was 3.20±0.26 in the preoperative period, which improved to 1.30±0.12 at the 6-month postoperative follow-up and remained at 1.25±0.11 in the long-term. The average BCTQ-FSS was 2.57±0.29 in the preoperative period, which improved to 1.28±0.12 at the 6-month postoperative follow-up and remained at 1.20±0.09 in the long-term. There were 7 cases (3.2%) of transient postoperative neurapraxia. No patient required to be converted to open technique. Conclusion: The endoscopic carpal tunnel release with Chow technique is an effective and safe surgical method for the treatment of idiopathic CTS. Level of Evidence; III

Caracterización de la comunicación ulnar-mediano palmar profunda en una muestra con material cadavérico / Characterization of ulnar-median deep palmar communication in a sample with cadaveric material

RESUMEN: La comunicación Ulnar-Mediano Palmar Profunda (CUMPP) es la conexión entre la rama profunda del nervio ulnar (NU) y la rama del nervio mediano (NM) que inerva a los músculos tenares como la cabeza superficial del flexor corto del pulgar. Son escasos los trabajos que se ocupan de esta rama comunicante, y su prevalencia es reportada con una amplia variabilidad, en un rango del 16-77 %. Este estudio no probabilístico, descriptivo, transversal, evaluó la frecuencia y características morfológicas de la CUMPP en 106 manos de especímenes cadavéricos frescos no reclamados, a quienes se les practicó necropsia en el Instituto de Medicina Legal de Bucaramanga (Colombia). Se observó rama comunicante CUMPP en 39 especímenes (50,2 %), de los cuales 12 (44,5 %) fueron bilate- rales, 15 (55,6 %) unilaterales, con predominio unilateral derecho para 9 casos (60 %), sobre el izquierdo de tan solo 6 casos (40 %). No se evidenciaron diferencias estadísticamente significativas con relación al lado de presentación (P=0,223). En 21 especímenes (54 %) se observó el tipo IV; mientras que el tipo I fue encontrado en 4 casos (10 %). El promedio de la longitud de la rama comunicante fue de 24,67 DE 6,46 mm; mientras que la distancia del punto proximal de la CUMPP al surco distal del carpo fue de 41,4 DE 2,6 mm. Nuestros hallazgos no son concordantes con lo reportado en la mayoría de estudios previos. Diversos factores como el tamaño de las muestras, las diferentes metodologías de medición y las expresiones fenotípicas de cada grupo de población evaluado, pueden explicar la variabilidad de la CUMPP.

SUMMARY: Deep Palmar Ulnar-Medium Communication (DPUMC) is the connection between the deep branch of the ulnar nerve (UN) and the median nerve (MN) branch, that innervates the thenar muscles as the superficial head of the short flexor of the thumb. Few studies dealing with this communicating branch, and its prevalence is reported with a wide variability in the range of 16-77 %. This non-probabilistic, descriptive, cross-sectional study; evaluated the frequency and morphological characteristics of DPUMC in 106 hands of fresh unclaimed cadaveric specimens, that underwent necropsy at the Institute of Legal Medicine of Bucaramanga (Colombia). DPUMC communicating branch was observed in 39 specimens (50.2 %), of which 12 (44.5 %) were bilateral, 15 (55.6 %) unilateral, with right unilateral predominance for 9 cases (60 %), on the left of only 6 cases (40 %). There were no statistically significant differences in relation to the presentation side (P = 0.223). In 21 specimens (54%), type IV was observed; while type I was found in 4 cases (10%). The average length of the communicating branch was 24.67 SD 6.46 mm; while the distance from the proximal point of the DPUMC to the distal carpal groove was 41.4 SD 2.6 mm. Our findings are not consistent with those reported in most previous studies. Various factors such as sample size, different measurement methodologies and phenotypic expressions of each population group evaluated can explain the variability of the DPUMC.

Estudio biométrico de la inervación de los músculos lumbricales de la mano humana / Biometric study of the innervation of the lumbrical muscles of the human hand

Los músculos lumbricales (ML) de la mano humana son claves en la propiocepción de la flexoextensión de los dedos. La descripción de su inervación indica que el nervio mediano (NM) inerva los dos ML laterales (L1 y L2) y el nervio ulnar (NU) los ML mediales (L3 y L4). Diversos autores han reportado una gran variabilidad de esta inervación, tanto en los nervios que entregan ramos para estos músculos, como también en la distribución de sus ramos y la presencia de troncos comunes. Por otra parte, el número de ramos que recibe cada ML y los puntos motores (Pm) de los mismos ha sido escasamente reportado. El objetivo de este estudio fue determinar número, ubicación y Pm de los ramos destinados a los ML de la mano humana. Así mismo se estableció el patrón de inervación más frecuente. Para ello se utilizaron 24 manos formalizadas, pertenecientes al laboratorio de Anatomía, de la Universidad Andrés Bello, sede Viña del Mar, Chile. Se realizó una disección convencional por planos de profundidad. En todos los casos, el ramo del músculo L1 se originó del nervio digital palmar propio lateral del dedo índice, de la misma forma, en el 100 % el L2 fue inervado por un ramo del nervio digital palmar común del segundo espacio interóseo. En relación a los ML mediales en un 100 % ambos músculos fueron inervados por ramos del ramo profundo del NU (RPNM). En el caso del L3 en un 92 % se presentó un tronco común con el segundo músculo interóseo palmar, asimismo para L4 existió un tronco común con el tercer músculo interóseo palmar en un 79 %. En el 29 %, el L3 presentó una inervación dual. Considerando como referencia la línea biestiloidea, los Pm de los ramos del NM fue de 63,96 mm para L1; 67,91 mm para L2 y 68,69 mm para L3. Para los ramos provenientes del RPNU fue de 69,87 mm para L3 y 69, 21 mm para L4. Los resultados obtenidos aportan al conocimiento anatómico de la inervación de los músculos lumbricales y es de utilidad en procedimientos de neurocirugía que busquen la restauración de la funcionalidad de la mano.

The lumbrical muscles (LM) of the human hand are key in proprioception of flexion and finger extension. The description of its innervation indicates that the median nerve (MN) innervates the two lateral LMs (L1 and L2) and the ulnar nerve (UN) the medial LMs (L3 and L4). Various authors have reported a great variability of this innervation, both in which nerve delivers branches for these muscles, as well as in the distribution of their branches and the presence of common trunks. On the other hand, the number of branches that each LM receives and the motor points (Mp) of these have been scarcely reported. The aim of this study was to determine the number, location and Mp of the branches destined for the LM of the human hand. Likewise, the most frequent innervation pattern was established. For this, 24 formalized hands, belonging to the anatomy laboratory, of the Universidad Andrés Bello, Viña del Mar, Chile, were used. Conventional depth plane dissection was performed. In all cases, the branch of the L1 muscle originated from the palmar digital nerve proper to the index finger, in the same way, in 100 % the L2 was supplied with a branch of the common palmar digital nerve from the second interosseous space. In relation to the LM, in 100 % both muscles were innervated by branches of the deep branch of the UN (DBUN). In the case of L3, 92 % presented a common trunk with the second palmar interosseous muscle. Likewise, in 79 % of the cases, there was a common trunk between the L4 and the third palmar interosseous muscle. In 29 %, the L3 presented a dual innervation. The distance between of the Mp-BEstL was 63.96 mm for L1, 67.91 mm for L2 and 68.69 mm for L3. This distance was 69.87 mm for L3 and 69, 21 mm for L4. The results obtained contribute to the anatomical knowledge of the innervation of the lumbrical muscles and is useful in neurosurgery procedures that seek to restore the functionality of the hand.

Electrophysiological evaluation of carpal tunnel syndrome female patients after vitamin D replacement / Avaliação eletrofisiológica de pacientes do sexo feminino com síndrome do túnel do carpo após reposição de vitamina D

Abstract Objective: The effects of vitamin D on the central and peripheral nervous system continue to be investigated today. In the present study, we aimed to evaluate pain and electrophysiologic response in patients with carpal tunnel syndrome (CTS) who have undergone replacement therapy due to vitamin D deficiency. Methods: Fifty female patients diagnosed with mild and moderate CTS and accompanied by vitamin D deficiency were included in this study. Nerve conduction study (NCS) was performed before and after vitamin D replacement, and the patient's pain was evaluated with Visual Analogue Scale (VAS). Results: When NCS were compared before and after treatment, there was a statistically significant improvement in the median distal sensory onset latency (DSOL) and sensory conduction velocity (CV) and motor distal latencies (DML) values (p=0.001; p<0.001; p=0.001, respectively). At the same time, there was a decrease in the VAS values in patients (p<0.001). When the two groups were compared there was an improvement in DSOL and sensory CV in both groups, but in DML only in moderate CTS group. Conclusion: In this study, it was shown that mild and moderate CTS patients had an improvement in pain and electrophysiological parameters after vitamin D replacement. Replacing vitamin D in early stages of CTS may be beneficial.

Resumo Objetivo: Os efeitos da vitamina D no sistema nervoso central e periférico continuam sendo investigados atualmente. Neste estudo, objetivamos avaliar a dor e a resposta eletrofisiológica em pacientes com síndrome do túnel do carpo (STC) submetidos a terapia de reposição devido à deficiência de vitamina D. Métodos: Cinquenta pacientes do sexo feminino diagnosticadas com STC leve e moderada e acompanhadas de deficiência de vitamina D foram incluídas neste estudo. O estudo da condução nervosa (ECN) foi realizado antes e após a reposição da vitamina D, e a dor do paciente foi avaliada com a Escala Visual Analógica (EVA). Resultados: Quando a ECN foi comparada antes e após o tratamento, houve uma melhora estatisticamente significativa na latência mediana do início sensorial distal (DSOL) e nos valores de velocidade de condução sensorial (VC) e latência distal motora (LDM) (p=0,001; p<0,001; p=0,001, respectivamente). Ao mesmo tempo, houve uma diminuição dos valores da EVA nos pacientes (p<0,001). Quando os dois grupos foram comparados, houve uma melhora no DSOL e no VC sensorial em ambos, mas no LDM apenas no grupo STC moderado. Conclusão: Neste estudo, foi demonstrado que pacientes com STC leve e moderada apresentaram melhora da dor e parâmetros eletrofisiológicos após a reposição de vitamina D. A substituição da vitamina D nos estágios iniciais da STC pode ser benéfica.

Sensibilidad y especificidad de tres métodos complementarios para el diagnóstico de síndrome de túnel carpiano / Sensitivity and specificity of three complementary methods in the diagnosis of carpal tunnel syndrome

Resumen: Introducción: Actualmente, no existe un estándar de referencia aceptado universalmente para el diagnóstico del síndrome de túnel carpiano, por lo que se le considera una patología de «clase latente¼, es decir, que carece de alguna prueba diagnóstica que dé certeza absoluta de la presencia de la enfermedad. Métodos: Estudio prospectivo, observacional y analítico en el cual se evaluaron los tres métodos diagnósticos utilizados para el síndrome de túnel carpiano (examen clínico, ecografía y electromiografía). En él, se establecieron valores de normalidad para cada método diagnóstico. Resultados: Se evaluó un total de 50 personas (14 hombres y 36 mujeres). El examen clínico presentó correlación positiva y significativa con el diámetro del nervio mediano afectado (ecografía) (R = 0.694 y p = 0.032). Los valores del área bajo la curva (AUC, por sus siglas en inglés) para la velocidad de conducción del nervio mediano (VCNM), velocidad de conducción de nervio cubital (VCNC) y latencia distal motora (LDM) por electromiografía fueron de 0.60, 0.519 y < 0.50, respectivamente, lo cual determinó que el valor diagnóstico de las características por electromiografía es malo. Conclusión: Nuestro trabajo establece al examen clínico como una herramienta de buena calidad, siendo el método más sensible para el diagnóstico de síndrome de túnel carpiano. Si existiera la necesidad de realizar una confirmación diagnóstica, la ecografía mostró ser un estudio altamente satisfactorio, el cual genera menos estrés, dolor e invasión al paciente, disminuyendo, a su vez, el gasto de salud y agilizando el proceso.

Abstract: Introduction: Currently there is no universally accepted standard of reference for the diagnosis of carpal tunnel syndrome so it is considered a «latent class¼ pathology, that is, it lacks any diagnostic tests that absolutely certain the presence of disease. Methods: Prospective, observational and analytical study evaluating the three diagnostic methods used for carpal tunnel syndrome (clinical examination, ultrasound and electromyography). Normality values were set for each diagnostic method. Results: 50 people (14 men and 36 women) were evaluated. The clinical examination showed a positive and significant correlation with the diameter of the affected median nerve (ecography) (R = 0.694, p = 0.032). The values of the under the curve area (UCA) for median nerve conduction speed (MNCS), cubital nerve conduction speed (CNCS), and distal latency (DL) by electromyography were 0.60, 0.519 and less than 0.50 respectively. This states that the diagnostic value of electromyography characteristics is bad. Conclusion: Our work establishes clinical examination as a good quality tool being the most sensitive method for diagnosing carpal tunnel syndrome. If there was a need for diagnostic confirmation, the ultrasound proved to be a highly satisfactory study generating less stress, pain and invasion to the patient, decreasing health expenditure and speeding up the process.