Estudio biométrico de la distribución de los ramos motores del nervio fibular superficial en el compartimiento lateral de la pierna en individuos brasileiros: implicancias clínicas y variaciones / Biometric study of the distribution of the motor branches of the superficial fibular nerve in the lateral compartment of the leg in Brazilian individuals: clinical implications and variations

El propósito del presente estudio fue conocer la distribución de los ramos motores del nervio fibular superficial (NFS) y de sus respectivas penetraciones en los músculos fibulares en relación al ápice de la cabeza de la fíbula, dividiendo el compartimiento lateral de la pierna en tres regiones a fin de hacer posible una visión más segura de sus correlaciones clínicas y quirúrgicas. A través de disección, se estudiaron 60 piernas pareadas de 30 cadáveres adultos, de ambos sexos, Brasileños, con edad promedio de 44,9 años, siendo 8 de sexo femenino y 22 del masculino. Después de la disección se registraron las distancias de los puntos de penetración de los ramos del NFS en los músculos fibular largo (mFL) y corto (mFC), localizándolos en los tercios proximal, medio o distal, según fuere el caso. Se observó que el mayor número de ramos penetraron en el mFL a nivel de la parte distal del tercio proximal de la pierna, mientras que en el mFC lo hicieron en las partes proximal y distal del tercio medio de la pierna. Los ramos motores para el mFL penetraban en el vientre muscular entre 48,06 y 141,56 mm, y los ramos para el mFC lo hicieron entre 163,34 y 209,67 mm del origen del nervio. No hubo diferencias estadísticamente significativas ni entre los lados derecho e izquierdo ni entre genéros. Independiente de las diferencias metodológicas entre los estudios disponibles, el detalle de la distribución nerviosa en este compartimiento, permitirá una mayor precisión en el momento de elegirse un área para colgajo de injerto autólogo y una menor chance de lesiones iatrogénicas durante cirugías de la región.

The purpose of the present study was to know the distribution of the motor branches of the superficial fibular nerve (SFN) and their respective motor points in the fibular muscles in relation to the apex of the head of the fibula, dividing the lateral compartment of the leg in three regions in order to make possible a safer view of your clinical and surgical correlations. Through dissection, 60 paired legs of 30 adult cadavers, of both sexes, Brazilians, with an average age of 44.9 years, 8 being female and 22 male, were studied. After the dissection, the distances of the motor points of the NFS branches in the fibularis longus (FLm) and brevis (FBm) muscles were recorded, locating them in the proximal, middle or distal thirds. It was observed that the largest number of branches penetrated the FLm at the level of the distal part of the proximal third of the leg, while in the FBm they did so in the proximal and distal parts of the middle third of the leg. The motor branches for the FLm penetrated into the muscular belly between 48.06 and 141.56 mm, and the branches for the FBm did between 163.34 and 209.67 mm of the origin of the nerve. There were no statistically significant differences between the right and left sides or between genres. Regardless of the methodological differences between the available studies, the detail of the nervous distribution in this compartment will allow a greater precision at the time of choosing an area for autologous graft flap and a lower chance of iatrogenic injuries during surgeries of the region.

The common fibular nerve (and its branches) in fetuses / El nervio fibular comun (y sus ramos) en fetos

The common fibular nerve (CFN), is a branch of the sciatic nerve (SN) that exits the popliteal fossa and is located at the tuberculum of the fibula. At the tuberculum of the fibula, the CFN bifurcates into deep (DFN) and superficial (SFN) fibular nerves. Forty fetuses were micro-dissected to (i) describe the course of the CFN in relation to the tuberculum and neck of the fibula in fetuses; (ii) describe the branches, distribution and relation of the DFN and SFN to muscles within the anterolateral compartment of the leg. The CFN, DFN and SFN were present in all specimens dissected; the CFN measured a mean length (mm) of 16.03 and 16.69 on the right and left sides respectively. Bifurcation of the CFN related to the tuberculum of fibula (right; left) - above 20/80 (25%); 14/80 (17.5%); below 6/80 (7.5%); 10/80 (12.5%) and at the tuberculum 54/80 (67.5%); 56/80 (70%). The DFN bifurcated into medial and lateral branches in 68/80 (85%) and 54/80 (67.5%) on the right and left sides, respectively. The SFN bifurcated into a medial branch in 78/80 (97.5%) and 76/80 (95%) on right and left sides, respectively and a lateral branch in 78/80 (97.5%) and 76/80 (95%) on right and left sides, respectively. The course and distribution of the CFN, DFN and SFN were consistent with the literature reviewed and descriptions found in standard anatomical textbooks. However, our findings show that the DFN has a variable number of branching patterns, which is unique to this fetal study and an intermediate branch of the SFN which was recorded in 3/80 cases.

El nervio fibular común (NFC), es un ramo del nervio isquiático (NI) que sale de la fosa poplítea y se ubica a nivel de la cabeza de la fíbula. A ese nivel, el NFC se bifurca en los nervios fibular profundo (NFP) y superficial (NFS). Cuarenta fetos fueron micro disecados para (i) describir el curso del NFC en relación con la cabeza y cuello de la fíbula en fetos; (ii) describir los ramos, distribución y relación del NFP y NFS con los músculos dentro del compartimento anterolateral de la pierna. El NFC, NFP y NFS estuvieron presentes en todos los especímenes disecados; el NFC presentó una longitud promedio de 16,03 y 16,69 (mm) en el lado derecho e izquierdo, respectivamente. La bifurcación del NFC se relacionó con la cabeza de la fíbula del lado derecho e izquierdo: por encima en 25% y 17,5%; por debajo 7,5% y 12,5 % y a nivel de la cabeza en 67,5 % y 70%. El NFP se bifurcó en ramos medial y lateral en un 85% en el lado derecho y 67,5% en el izquierdo. El NFS se bifurcó en una ramo medial en el 97,5% y 95% en los lados derecho e izquierdo, respectivamente, y un ramo lateral en el 97,5% y 95% del lados derecho e izquierdo, respectivamente. El curso y distribución del NFC, NFP y NFS coincidieron con la literatura revisada y textos de anatómia normal. Sin embargo, observamos que el NFP tiene un número variable de patrones de ramificación, único para este estudio fetal y un ramo intermedio del NFS que fue visto en 3/80 casos.

Sartorial branch of saphenous nerve: anatomical relationship with bony landmarks and great saphenous vein / Ramo sartorial del nervio safeno safeno: relación anatómica con puntos de referencia óseos y de la vena safena magna

Sartorial branch of saphenous nerve (medial crural cutaneous nerve) originates at the medial side of the knee and descends along the great saphenous vein (GSV) to innervate the medial aspect of the leg. Its anatomy is of concern in surgical procedures and anesthetic block. However, the measurement data related to palpable bony landmarks with comparison between sexes and sides are lacking. Dissection was done in 95 lower limbs from both sexes. We found that the nerve pierced the deep fascia alone in most cases (92.6%). This piercing point was always distal to the adductor tubercle with the distance of 5-6 cm which was 15% of the leg length (the distance between the adductor tubercle and medial malleolus). The nerve was 7 cm medial to the tibial tuberosity. At the mid-level of leg length, the nerve was slightly over 4 cm medial to the anterior tibial margin. The nerve terminally divided 7 cm proximal to the medial malleolus. Furthermore, the anatomical relationship between the nerve and the GSV was highly variable. The nerve was constantly anterior, posterior or deep to the GSV in 8.4%, 15.8% and 2.1%, respectively. Crossing between the two structures was observed in 57.9% of specimens and the distance to the medial malleolus was 18 cm. Symmetry was found in most parameters and significant gender differences were observed in some distances. These results are important for avoiding the sartorial nerve injury and locating the nerve during relevant procedures.

El ramo sartorial del nervio safeno (nervio cutáneo medial de la pierna) se origina en el lado medial de la rodilla y desciende a lo largo de la vena safena magna (VSM) para inervar la cara medial de la pierna. Su anatomía es motivo de preocupación en los procedimientos quirúrgicos y en el bloqueo anestésico. Sin embargo, los datos de medición relacionados con puntos de referencia óseos palpables y la comparación entre los lados y en ambos sexos son escasas. Se realizó la disección en 95 miembros inferiores de ambos sexos. Se encontró que el nervio perforó la fascia profunda en la mayoría de los casos (92,6%). Esta punta de perforación fue siempre distal al tubérculo del músculo aductor magno a una distancia de 5-6 cm, que representaba el 15% del largo de la pierna (la distancia entre el tubérculo del aductor magno y el maléolo medial). El nervio se localizaba 7 cm medial a la tuberosidad tibial. Al nivel del tercio medio en ambas piernas, el nervio estaba a una distancia un poco mayor a 4 cm medial al margen anterior de la tibia. El nervio se dividía 7 cm proximal al maléolo medial. Por otra parte, la relación anatómica entre el nervio y la VSM fue muy variable. El nervio era constantemente anterior, posterior o profundo a la VSM en 8,4%, 15,8% y 2,1%, respectivamente. Cruce entre las dos estructuras anatómicas se observó en el 57,9% de las muestras y la distancia hasta el maléolo medial fue de 18 cm. La simetría se encuentra en la mayoría de los parámetros y diferencias de sexo significativas se observaron en algunas distancias. Estos resultados son importantes para evitar la lesión del nervio sartorial y localizar el nervio durante los procedimientos pertinentes.

Inervación y localización biométrica de los puntos motores del músculo tríceps sural / Innervation and localization of the motor points of triceps surae muscle

La inervación de los músculos es descrita de forma general, faltando datos biométricos sobre el lugar donde penetran los nervios en el vientre muscular. Con el propósito de conocer la inervación y los puntos motores de los componentes del músculo tríceps sural en la población chilena, estudiamos 18 miembros inferiores de individuos, adultos, fijados en formaldehido al 10 por ciento. Se realizó disección por planos, identificando los nervios dirigidos a las cabezas lateral y medial del músculo gastrocnemio y al músculo sóleo, esquematizando y fotografiando los hallazgos. Se identificó el origen de los ramos, respecto a una línea trazada entre las partes más prominentes de los epicóndilos femorales (LBEC), así como también, los puntos de ingreso en el vientre muscular, clasificando estos ramos como principales (R) y secundarios (RS). En todas las muestras la inervación provino del nervio tibial. La cabeza medial del músculo gastrocnemio recibió un ramo (R1) en 15 casos y dos (R1 y R2) en 3 casos. El origen de R1 se localizó en promedio a 23,6 +/- 11,5 mm distal a la LBEC; en 15 casos el R1 se dividió hasta en 4RS. Los puntos donde ingresaron estos últimos respecto a LBEC fueron en promedio 40,4 +/- 11,1 mm el RS1 y 46,9 +/- 9,1 mm el RS2. La cabeza lateral recibió un ramo en 17 casos y dos en 1 caso; el origen de R1 se localizó en promedio a 35,6 +/- 11,8 mm distal a la LBEC; en 12 casos el R1 se dividió hasta en 4RS. Los puntos donde ingresaron estos últimos respecto a LBEC fueron 49,4 +/- 9,3 mm el RS1 y 52,4 +/- 10,6 mm el RS2. El músculo sóleo recibió su ramo de un tronco común con la cabeza lateral del gastrocnemio en 7 casos y un ramo directo R1 en 6 casos y dos ramos (R1 y R2) en 5 casos, de los cuales, en 3 de ellos, recibió un ramo anterior y uno posterior; el origen de R1 se localizó a 40,4 +/- 14,4 mm de LBEC; el origen del tronco común se ubicó a 20,2 mm de esta línea. El R1 se dividió hasta en 7 RS. Estos resultados son un aporte a la anatomía...

The knowledge of innervation of muscles is generally described, but we can complement the point where the nerves penetrate the muscle belly, from the biometric standpoint. In order to know the innervation and motor points in the components of the triceps surae muscle, 18 formolized lower limbs of adult Chilean individuals were studied. Planes dissection was performed by identifying the point nerve of the lateral and medial head of gastrocnemius muscle and soleus muscle. All specimens were schematized and photographed. We identified the source of the branches, about a line drawn between the most prominent parts of the femoral epicondyles (BECL), as well as the points of entry into the muscle belly, classifying these branches as principal (BR) and secondary ( SBR). In all samples the innervations came from the tibial nerve. The medial head of the gastrocnemius muscle received one branch (BR1) in 15 cases and two (BR1 and BR2) in 3 cases. The BR1 origin is located on average 23.6 +/- 11.5 mm distal to the BECL, in 15 cases the BR1 split up into four SBR. The points where these latter entered in muscular belly regarding BECL were on average: 40.4 + 11.1 mm (SBR1) distal to this line and 46.9 +/- 9.1 mm (SBR2). The lateral head received one branch in 17 cases and two in 1 case; the origin of BR1 was found on average to 35.6 +/- 11,8 mm distal to the BECL; in 12 cases the BR1 was divided up in four SBR. Regarding to BECL the SBR entered in muscle belly distal to this line, 49.4 +/- 9.3 mm (SBR1) and 52.4 +/- 10.6 mm (SBR2). The soleus muscle received his branch from a common trunk with the lateral head of the gastrocnemius in 7 cases and one direct branch BR1 in 6 cases and two branches (BR1 and BR2) in 5 cases, of which 3 of them received one anterior branch and posterior branch; the origin of BR1 was located 40.4 ± 14.4 mm distal to the BECL; the common trunk origin was located at 20.2 mm distal from this line...

Descripción anatómica de la irrigación del colgajo sural a pedículo distal en piezas cadavéricas / Anatomical description of the blood supply of the distally based sural flap in eight lower limbs

Background: The distally based sural fasciomyocutaneous flap is widely used in the coverage of deep soft tissue defects on the distal third of lower limbs. Aim: To perform a morphometric description of the perforating arteries that supplies the flap. Material and Methods: We used eight lower limbs from amputations performed above the knee. The limbs were injected through the popliteal artery with red colored latex. After the injection, the limbs were dissected to obtain a distally based sural fasciomyocutaneous flap. Once the fasciomyocutaneous island was obtained, the flap was elevated dissecting its pedicle. Once the whole flap was dissected, a morphometric registry of the lateral and medial perforating arteries was performed. The pivot point for the flap was set 5 cm above the upper border of the lateral malleolus. The distance between the upper border of the lateral malleolus and the emergence of each perforating artery was measured. Results: The sural nerve was identified in all eight dissections. A perineural plexus was the source of the blood supply of the flap, in three of the eight dissections. In two dissections, three sural arteries were identified (medial, median and lateral). The lateral sural artery was identified in two dissections and the medial and lateral arteries in one. Three to six perforating arteries were identified in the medial part of the pedicle and four to five perforating arteries in the lateral part of the pedicle. Conclusions: The distribution of the sural artery along the flap's pedicle is very variable. The most common distribution in these dissections was in the form of a perineural plexus. Considering the distance from the lateral malleolus to the emergence of the perforating arteries, the pivot point of the flap, should be set approximately at 5.5 centimeters above the lateral malleolus.

El colgajo sural fasciomiocutáneo es ampliamente utilizado en la reparación de defectos profundos de tejidos blandos del miembro inferior distal. Este estudio describe su base anatómica mediante la morfometría de las arterias perforantes en una muestra de nuestra población chilena. Material y Método: Se utilizaron 8 miembros inferiores de amputaciones supracondileas. Previa repleción con látex coloreado vía poplítea, se procedió a disecar los miembros inferiores para así obtener un colgajo fasciomiocutáneo sural de pedículo distal. Una vez obtenida la isla, se procedió a elevar el colgajo y disecar su pedículo. Luego se realizó la mor-fometría de las arterias perforantes tanto por lateral como por medial al pedículo, desde el punto pívot definido a 5 cm cefálico al maléolo lateral, hasta la base de la isla fasciomiocutánea. Se describió la distribución de la irrigación y se realizó registro fotográfico de los hallazgos. Resultados: El paquete vasculonervioso sural con un nervio fue identificado en todas las disecciones. La morfología arterial predominante fue la distribución como plexo perineural. Se reconocen tres arterias surales (lateral, mediana y medial). Fueron identificadas 3 a 6 perforantes hacia medial y 4 a 5 hacia lateral del pedículo. Conclusiones: La distribución de la arteria sural es variable y en la mayoría de los casos se presenta como plexo perineural. Dados los hallazgos de las perforantes, consideramos que el punto de giro del colgajo se encuentra aproximadamente a 5,5 cm del maleolo lateral, lo cual coincide con el punto ideal para la viabilidad del colgajo informado en otras series.

Bloqueo poplíteo para reducciones ortopédicas de extremidad inferior / Popliteal block for inferior extremity orthopedic reductions

Popliteal sciatic block is considered a good alternative analgesia for performing leg, ankle or foot’s fracture reduction at an emergency room. We hypothesized that performing the procedure in prone position rather than supine is better tolerated by the patients. Since 1995, we have used popliteal sciatic block carried out in both positions. Our study consists in 507 patients with fractures of the involved segment of the lower limb who presented at the emergency room from 1998 to 2008. All of them were treated with closed reduction and immobilization under popliteal sciatic block analgesia. The Procedure was performed by orthopedic surgeons guided by an anesthesiologist. 22.5 ml of lidocaine at 1.33 percent was used for obtaining paresthesia. Pain outcome was evaluated using the Visual Analog Scale (VAS) and by patient and surgeon questionnaire. Patient and surgeon’s satisfaction was 90 percent and 94 percent, respectively. Our series reports a simple, reliable and safe analgesia technique for closed fracture’s reduction of the lower limb at the emergency department.

Para reducciones de fracturas de pierna, tobillo y pie generalmente basta un bloqueo ciático, que realizado en la posición prona, produce dolor e incomodidad al paciente. Desde el año 1995 utilizamos en nuestro hospital el bloqueo poplíteo vía posterior en posición supina para estos procedimientos. Se analiza la experiencia de 10 años con 507 pacientes con lesiones del segmento a los cuales se les practicó reducción de su fractura con bloqueo poplíteo realizado por residentes de Ortopedia y Traumatología capacitados y supervisados por anestesiólogos. Se utilizó lidocaína 22,5 ml al 1,33 por ciento obteniéndose parestesias. La evaluación se realizó mediante escala EVA y encuesta al operador y paciente. El 90 por ciento de los pacientes y el 94 por ciento de los operadores dan una evaluación positiva del procedimiento. La técnica siendo simple, confiable y segura proporciona una excelente anestesia para reducciones de la extremidad inferior.

Somatotopic Arrangement and Location of the Corticospinal Tract in the Brainstem of the Human Brain

The corticospinal tract (CST) is the most important motor pathway in the human brain. Detailed knowledge of CST somatotopy is important in terms of rehabilitative management and invasive procedures for patients with brain injuries. In this study, I conducted a review of nine previous studies of the somatotopical location and arrangement at the brainstem in the human brain. The results of this review indicated that the hand and leg somatotopies of the CST are arranged medio-laterally in the mid to lateral portion of the cerebral peduncle, ventromedial-dorsolaterally in the pontine basis, and medio-laterally in the medullary pyramid. However, few diffusion tensor imaging (DTI) studies have been conducted on this topic, and only nine have been reported: midbrain (2 studies), pons (4 studies), and medulla (1 study). Therefore, further DTI studies should be conducted in order to expand the literature on this topic. In particular, research on midbrain and medulla should be encouraged.

Inervación de los músculos fibulares largo y corto en individuos chilenos: estudio anatómico y biométrico / Innervation of the fibularis longus and brevis muscles in chilean individuals: anatomic and biometric study

La inervación de los músculos del compartimiento lateral de la pierna es conocida desde un punto de vista general y su dependencia del nervio fibular superficial (NFS) es descrita en la mayoría de los textos clásicos. Sin embargo, detalles del número de ramos nerviosos que reciben los músculos y a que nivel se encuentran sus puntos motores es poco conocido, sobretodo en nuestra población. Basado en lo anterior y con el propósito de aportar datos respecto a las variables mencionadas y determinar niveles de origen y localización de los puntos motores de los músculos fibulares largo y corto, se realizó un estudio anatómico y biométrico en 16 piernas formolizadas de individuos adultos, chilenos. Se realizó disección por planos, identificando en la parte proximal de la pierna el nervio fibular común (NFC) y su punto de división en nn. fibular superficial (NFS) y fibular profundo (NFP), localizando los ramos primarios (R1,R2,R3 o más) dirigidos a los músculos en estudio. Para determinar su punto de origen y punto de penetración en éstos, se identificó la parte más prominente del epicóndilo lateral del fémur, desde el cual se registró la distancia entre este punto de referencia y las variables mencionadas. Cuando hubo subdivisiones en ramos secundarios (RS), se registró también su punto de origen y punto de penetración en el vientre muscular. En el m. fibular largo se observó en los 16 casos R1 y R2; 13 casos con R1, R2 y R3; 5 casos con R1, R2, R3 y R4 y 1 presentó 5R. El R1 provino del NFC en 6 casos (37,5 por ciento), del NFS en 9 (56,3 por ciento) y del nervio cutáneo dorsal medial (división precoz de NFS) en 1 (6,3 por ciento); el R2 se originó en el NFC en 2 casos (12,5 por ciento), del NFS en 13 (81,3 por ciento) y del nervio cutáneo dorsal medial en 1(6,3 por ciento); el R3 fue emitido por el NFS en 11 casos y por el nervio cutáneo dorsal intermedio (división precoz NFS) en 2 casos. Los ramos primarios se subdividieron hasta en 5 RS. El m. fibular corto...

The innervation of the muscles of the lateral compartment of the leg is known from a general point of view and its dependence of the superficial fibular nerve (SFN) is described in the majority of the classic texts. Nevertheless, there is little information regarding detail of the number of nervous branches that muscles receive, or the location of its motor points, principally in our population. The objective of this study was to contribute to anatomic knowledge of the mentioned variables and determine the origin levels of muscular branches and the motor points location in the fibularis longus and fibularis brevis muscles. We carried out an anatomical and biometric study in 16 cadaveric legs fixed in formaldehyde of adult, Chilean individuals. Dissections were made, identifying in the proximal part of the leg the common fibular nerve (CFN) and its division point in superficial (SFN) and deep (DFN) fibularis nerves, locating the primary branches (R1, R2, R3 or more) directed for the muscles in the study.To determine the origin level of muscular branches and motor point, we identified the most prominent part of the lateral epicondyle of femur, from which the distance was recorded between this point of reference and the mentioned variables. When there were subdivisions in secondary branches (SB), also we recorded its point of origin and motor point in the muscular belly. In the fibularis longus muscle we observed R1 and R2 in 16 cases; R1, R2 and R3 in 13 cases; R1, R2, R3 and R4 in 5 cases and 5R in one case. The R1 originated from the CFN in 6 cases (37.5 percent), from the SFN in 9 (56.3 percent) and from the medial dorsal cutaneous nerve (SFN precocious division) in 1 (6.3 percent); The R2 originated in the CFN in 2 cases (12.5 percent), of the SFN in 13 (81.3 percent) and of the medial dorsal cutaneous nerve in 1 (6.3 percent); the R3 was emitted by the SFN in 11 cases and by the intermediate dorsal cutaneous nerve (SFN precocious division) in 2...

Morfometría de los nervios isquiático, tibial y fibular común en el hombre / Morphometry of the sciatic, tibial and common fibular nerves in man

El nervio isquiático, el más extenso del cuerpo humano, emerge de la pelvis por el foramen isquiático mayor, dividiéndose proximal a la articulación de la rodilla en los nervios tibial y fibular común. Con frecuencia, estos nervios son afectados por accidentes, por tanto, la microcirugía reparadora requiere de detallada información anatómica para efectuar con éxito sus procedimientos. El nervio isquiático puede ser lesionado por heridas penetrantes, en las luxaciones posteriores de la articulación coxal y por inyecciones intramusculares mal aplicadas en la región glútea, siendo rara la lesión del nervio tibial por estar situado profundamente protegido. En cambio, la lesión del nervio fibular común, es frecuente debido a su posición superficial, quedando muy expuesto cuando abandona la fosa poplítea y rodea el cuello de la fíbula. Realizamos el estudio debido a la escasa información morfométrica y estereológica de estos nervios. Se disecaron en 5 cadáveres de individuos adultos, de sexo masculino los nervios isquiático, tibial y fibular común. Se obtuvieron secciones transversales de cada uno de los nervios a nivel de la división del nervio isquiático y del origen de los nervios tibial y fibular común. Realizamos cortes de 5 µm de grosor, los que fueron teñidos con H.E. Obtuvimos información cuantitativa sobre medidas morfométricas, determinamos el número de fibras nerviosas de cada fascículo así como el número de fascículos existente en cada nervio. Además, determinamos, por planimetría a través del conteo de puntos, el área de los fascículos que constituían cada nervio. El número de fascículos en el nervio isquiático varió de 63 a 70, con un promedio de 66,8 (D. E. 2,59). En el nervio tibial, el número de fascículos varió de 35 a 43, con un promedio de 30 (D. E. 3,00) y en el nervio fibular común el número de fascículos varió de 17 a 25, con un promedio de 21 (D. E. 2,92). El número promedio de fibras en el nervio ciático fue de 64.535 (D. E. 3.193). En los ...

The sciatic nerve, the longest of the human body, emerging from the pelvis through the greater sciatic foramen, dividing proximal to the knee joint in the tibial and common fibular nerves. Frequently these nerves are affected by accidents, therefore, the repairing microsurgery requires detailed anatomical information in order to successfully complete these procedures. The sciatic nerve can be damaged by penetrating injuries in the posterior luxations of the hip joint, and by intramuscular injections, given incorrectly the gluteal region. Injury to the tibial nerve is rare as it is deeply located and protected. On the other hand, injury to the common fibular nerve is frequent due to its superficial position, leaving it exposed when it leaves the popliteal fossa and surrounds the fibular neck. The study was conducted due to scarce morphometric and stereologic information on these nerves. The sciatic tibial and common fibular nerves in five cadavers of individual male adults were dissected. Transverse section of each of the nerves were obtained at the level of the division of the sciatic nerve and of the origin of the tibial and common fibular nerves. Sections of 5 µm were cut which were stained with H.E. We obtained quantitative information regarding morphomtric measurements, determined the number of nerve fibres of each fascicle, as well as the number of existing fascicles in each nerve. We also determined by planimetry, through counting of points, the area of the fascicles that constituted each nerve. The number of fascicles in the sciatic nerve varied from 63 to 70 with an average of 66.8 (S.D. 2.59). In the tibial nerve the number of fascicles varied from 17 to 25 with an average of 21 (S.D. 2.92). The mean number of fibres in the sciatic nerve as of 64,535 (S.D. 3,193). In the tibial nerve it was 40,317 (S.D. 4,067) and in the common fibular nerve it was: 22,191 (S.D. 1,038). The median area of the sciatic, tibial and common fibular nerves was: 11,42 mm².

Formación del nervio sural en individuos chilenos / Sural nerve formation in Chilean individuals

La inervación cutánea de la región posterior de la pierna esta dada por el nervio cutáneo sural medial (NCSM), el nervio cutáneo sural lateral (NCSL), el nervio sural (NS) y el nervio safeno. Estos ramos son variables pudiendo los dos primeros, ser independientes o estar unidos y formar el nervio sural. Con el propósito de determinar la formación del nervio sural y los niveles de origen de los nervios NCSM y NCSDL, disecamos 12 piernas formolizadas, 7 izquierdas y 5 derechas, de individuos chilenos, adultos. El punto de origen y unión de los nervios NCSM y NCSL se localizó en relación a una línea transversal trazada entre los puntos más prominentes de los cóndilos femorales (LBE), así como una línea trazada entre los dos maléolos (LBM). La distancia entre ambas líneas fue en promedio 31,8 cm.; el punto de origen del NCSL se situó en promedio a 3,75 cm proximal a la LBE y el del NCSM a 2,23 cm proximal a la misma línea. En 7 muestras (58,3 por ciento) observamos unión de los dos ramos formando el NS ( en dos de ellas a través de un ramo comunicante fibular) y en las restantes se mantuvieron independientes. El punto de unión de los nervios referidos fue localizado proximal a la LBM. Los resultados obtenidos complementarán el conocimiento anatómico de la inervación sensitiva de la pierna.

The skin of the posterior region of the leg is supplied by the medial sural cutaneous (MSCN), lateral sural cutaneous (LSCN), sural (SN) and the safenous nerves. These nerves present variations where the first and second nerves can be independents or both join to form the sural nerve. The objective of this research was to determine the sural nerve formation and the origin level of the MSCN and LSCN. We dissected 12 legs fixed in formaldehyde 10 percent (7 of the left side and 5 of the right side), from of adult Chilean individuals. The origin and join points of the MSCN and LSCN nerves were localized in relation to horizontal line between the prominent points of the femoral condyles (BCL), so as a horizontal line between the two malleolus (BML), respectively. The distance between both lines was average 31.8 cm; the origin point of the LSCN was 3.75 cm proximal to BCL and the origin point of the MSCN was 2.23 cm proximal to this line. In 7 cases we observed both nerves forming the sural nerve (in two of them, by a fibular communicant branch) and in rest cases were independents. The joint point of the referred nerves was localized proximal to BML. These results are a contribution to the anatomic knowledge of the sensitive innervation of the leg.

Traumatic lesions of internal saphenous nerve and branches / Lesões traumáticas do nervo safeno interno e seus ramos

OBJECTIVE: To show a rare lesion that sometimes simulates vascular disorder of the lower extremities. METHOD: Three patients were operated and the follow-up period was eight months, the surgical technique was neurotomy of the infrapatellar and descendent branches. RESULTS: In two cases there were almost total pain resolution, and in other case improvement only. CONCLUSION: Surgical treatment yields good results in this type of internal saphenous nerve lesion, and could be useful as an alternative to conservative treatment.

OBJETIVO: Apresentar lesões raras do nervo safeno interno interno, que muitas vezes, simulam doenças vasculares dos membros inferiores. MÉTODO: Três pacientes foram operados e acompanhados por um período de oito meses. A técnica cirúrgica consistiu na neurotomia dos ramos infrapatelar e descendente do nervo safeno interno. RESULTADOS: Nos dois primeiros casos houve quase desaparecimento total da dor em pouco tempo e no terceiro apenas melhora. CONCLUSÃO: O tratamento cirúrgico dá bons resultados neste tipo de lesão do nervo safeno interno e poderia ser útil como alternativa ao tratamento conservador.

L4-L5-S1 human dermatomes: a clinical, electromyographical, imaging and surgical findings / Dermátomos humanos L4, L5 e S1: achados clínicos, eletromiográficos, de imagem e cirúrgicos

There is substantial controversy in literature about human dermatomes. We studied L4, L5, and S1 inferior limb dermatomes by comparing clinical signs and symptoms with conduction studies, electromyographical data, neurosurgical findings, and imaging data from computerized tomography (CT) or magnetic resonance imaging (MRI). After analyzing 60 patients, we concluded that L4 is probably located in the medial aspect of the leg, L5 in the lateral aspect of the leg and foot dorsus, and S1 in the posterior aspect of the backside, tight, leg and plantar foot skin. This is the first time that these human dermatomes have been evaluated by combined analysis of clinical, electromyographical, neurosurgical, and imaging data.

Há controvérsia na literatura sobre os dermátomos humanos. Estudamos dermátomos do membro inferior comparando sinais e sintomas com estudos eletromiográficos, de imagem e achados cirúrgicos. Analisando 60 pacientes, concluímos que o dermátomo L4 provavelmente está localizado na região medial da perna, o dermátomo L5 na região lateral da perna e dorso do pé, e o dermátomo S1 na nádega, região posterior da coxa e da perna e na região plantar. Este é o primeiro estudo que os dermátomos do membro inferior foram analisados através de dados clínicos, eletromiográficos, imagem e achados cirúrgicos.

Neurovascular pedicles of the tibialis anterior muscle in children / Pedículos neurovasculares del músculo tibial anterior en niños

The importance of the tibialis anterior muscle in infantile orthopedic transposition surgeries, as in myelomemngoceles, it bases this research about the neurovascular pedicles of the tibialis anterior muscle. The study was conducted on 34 legs of human cadavers that were one year old or younger at the time of death. It was observed that the tibialis anterior muscle most frequently presented from 7 to 10 arterial branches (52.4 percent). In 97.1 percent of cases these branches were derived from the anterior tibial artery. In one case the anterior tibial artery was missing and the muscle was supplied by the fibular artery. Thirty-nine and seven tenths percent of arterial branches entered the superior third of the muscle; the middle third received 40.1 percent of the branches and the inferior third received 20.2 percent of the branches. The deep fibular nerve exclusively supplied the innervation, which in91.2 percent of cases, gave off from 2 to 4 branches to the muscle, mainly to the superior (46.2 percent) and middle third (43.0 percent). Most frequently, there were two neurovascular pedicles supplying the superior third and one supplying the middle third.

La importancia del músculo tibial anterior en cirugías de transposición ortopédica en niños, así como en casos de mielomeningocele, fundamenta su estudio respecto a sus pedículos neurovasculares. El estudio se realizó en 34 miembros inferiores de cadáveres de niños de un año o menos de edad. Se observó que el músculo tibial anterior presentaba con frecuencia 7 a 10 ramas arteriales (52,4 por ciento). En 97,1 por ciento de los casos estos ramos eran derivados de la arteria tibial anterior. En dos casos, la arteria tibial anterior estaba ausente y el músculo suplió su irrigación con la arteria fibular. En relación a la entrada de las ramas, 39,7 por ciento lo hacen en el tercio superior del músculo. El tercio medio recibe 40,1 por ciento de las ramas y el tercio inferior recibe 20,2 por ciento de ellas. El nervio fibular profundo es la fuente principal de inervación, en 91,2 por ciento de los casos provee 2 a 4 ramos para el músculo, de ellos el 46,2 por ciento termina en el tercio superior y el 43 por ciento en el tercio medio. Con mayor frecuencia, existen dos pedículos neurovasculares supliendo el tercio superior y uno supliendo el tercio medio del músculo tibial anterior.

Precise localization of motor branching and motor points: a cadeveric study.

In order to facilitate precise localization of motor nerves and motor points, and to increase effectiveness and minimize complications of neurolytic blocks. Locations of motor branching points and motor points of 31 cadavers were measured as relative to medial femoral condyle and mid posterior calf line. Needle insertion points 1.5 centimeters and 0.5 centimeters proximal to the level of medial femoral condyle yielded the best chance (66.25%-76.19%) of finding motor branches to medial gastrocnemius muscles and lateral gastrocnemius respectively. The points with greatest chance of success (67.69%-86.41%) for soleus, tibialis posterior and flexor hallucis longus motor branches blocks were found to be at 2.5, 6, and 11 centimeters distal to the level of medial femoral condyle respectively. However; even if these points are used as guidelline when performing motor branch block prodedure, the risk of sensory nerve fiber injury are still as high as 20.98% upto 50.0%. To avoid such complication, the authors have proposed a set of landmarks that would make it possible to access all of the motor branches of any single calf muscle with only three or less needle insertions, and still maintaining about 1% risk of sensory fiber injury.

Prevention of phantom sensations after spinal anesthesia.

BACKGROUND AND OBJECTIVES: Phantom limb sensation (PLS) after the spinal anesthesia is an unpleasant experience. The occurrence rate was 80 to 83 per cent from previous studies. The purpose of this study is to evaluate the incidence of PLS, comparing between placing the lower limbs in the neutral position when analgesic level reach L1 dermatome (L1 group) and T6 dermatome (T6 group). METHODS: Ninety ASA physical status I-II patients, 19-50 year of age, scheduled for lower abdominal surgery under spinal anesthesia were enrolled. Immediately after the spinal injection, the patients were placed supine with one of lower limbs flexed (both hip and knee) and the other kept straight in the neutral position. The analgesic levels were checked every minute; the flexed limbs were turned to the neutral position when the analgesic level reached L1 and T6, the L1 group and the T6 group respectively. The images of the lower limbs and patients' satisfactions were evaluated 15 minutes after the blockage. RESULTS: Twenty per cent of the patients in the L1 group experienced PLS of the flexed limbs while 82.2 per cent of the patients in the T6 group did (P<0.05). None of the patients in the L1 group felt unsatisfied with PLS, on the other hand, 11.1 per cent of the patients in the T6 group expressed their dissatisfaction and would like to have their limbs extended. CONCLUSIONS: This study revealed that by placing the lower limbs in the neutral position immediately after the spinal injection, before the unwanted positions are memorized, could effectively minimize phantom limb sensation after spinal anesthesia.

Normal values of lower limb nerve conduction in Kuwait. Part II

To establish the normal electrophysiological values of the common lower limb nerves and to study the relationship of conduction velocity [CV] of the lower limb nerves to height and age in healthy adult subjects. Nerve conduction investigations were performed on the lower limbs of 51 screened healthy volunteers using standard electrophysiological techniques. Fifty-one subjects [21 males and 30 females] participated in the study. The mean [ +/- SD] ages of the subjects were 38 [ +/- 8.82] and 36 [ +/- 8.58] years for males and females, respectively. The tibial motor nerve showed a mean [ +/- SD] CV of 46.1 [ +/- 3.3] m/s, distal latency [DL] 4.4 [ +/- 0.8] ms, and amplitude 8.8 [ +/- 3.4] mV for males. For females, the results were CV 47.8 [ +/- 3.4] m/s, DL 3.9 [ +/- 0.85] ms and amplitude 12.0 [ +/- 3.4] mV. Peroneal motor parameters were CV 47.1 [ +/- 3.3] m/s, DL 3.9 [ +/- 0.53] ms, amplitude 5.6 [ +/- 2.2] mV for males and 49.3 [ +/- 2.3] m/s, 4.0 [ +/- 0.56] ms, 6.0 [ +/- 2.2] mV for females, respectively. The sural sensory nerve parameters were CV 48.7 +/- 6.0 m/s, DL 2.9 [ +/- 0.3] ms, amplitude 18.9 [ +/- 3.3] micro V for males and 51.5 [ +/- 4.9] m/s, 2.7 [ +/- 0.24] ms and 21.6 [ +/- 6.3] micro V for females. Most CV values were significantly correlated with height, and there was a significant difference between males and females. However, after adjustment for height by the linear regression method, all significant gender differences disappeared. This study established the normative conduction parameters of the commonly tested nerves of the lower limbs for our electromyography laboratory in Kuwait. Gender differences disappeared when the data were adjusted for age and height

Saphenous nerve entrapment manifested as proximal cruralgia

A 16 years old boy had continuoous pain in the right testis, groin, and the medial aspect of the thigh and knee for 16 months. The onset of symptoms was acute and pain distribution included a retrograde area in relation to the entrapment site. Tinel's sign was the clue for diagnosis. Diagnosis was confirmed at operation and division of the aponeurosis of Hunter's canal relieved the symptoms for three days. A second surgical exploration, proximal to the former one, was performed after five months. The right femoral nerve was found normal. This new operation was therapeutically ineffective. Causes of pain distribution and relapsed pain are discussed. The relapse was attributed to myofascial pain syndrome. This diagnosis should be considered independently of the correct treatment of the primary lesion.