Localization of the nerve entry points of thigh adductor muscles by spiral computed tomography: a novel anatomical guide for chemical neurolysis in treating muscle spasticity / Localización de los puntos de entrada del nervio de los músculos aductores del muslo mediante tomografía computarizada espiral: una nueva guía anatómica para la neurolosis química en el tratamiento de la espasticidad muscular

The nerve entry points (NEPs) cannot yet be accurately localized for the treatment of thigh adductor muscles spasticity in chemical neurolysis. The aim of this study was to identify the location and depth of the NEPs of thigh adductor muscles by spiral computed tomography (CT) and bony landmarks. Forty lower limbs of twenty adult cadavers were dissected in supine position. A curved line on skin surface from the tip of greater trochanter of femur to the center of pubic tubercle was designated as the horizontal reference line (H). Another curved line from the tip of great trochanter to the lateral epicondyle of femur was designated as the longitudinal reference line (L). Following dissection, the NEPs were labeled with barium sulfate, and their body surface projection points (P) were determined by spiral CT. Projection of NEP in the opposite direction was designated as P'. The percentage location of the intersections (PH and PL) of P with the H and L and the percentage depth of NEPs were determined with the Syngo system. The PH for the NEP of pectineus, gracilis, adductor longus, adductor brevis and adductor magnus muscles branch were located at 76.41±0.71 %, 93.85±2.07 %, 92.05±2.15 %, 80.75±1.20 % and 88.08±1.09 % of the H, respectively. The PLwere at 1.64±0.04 %, 29.89±1.90 %, 16.06±1.32 %, 11.66±0.11 % and 22.94±0.90 % of the L, respectively. The depth of NEP from P points were at 17.52±0.52 %, 38.38±2.75 %, 20.88±0.79 %, 20.35±0.82 % and 39.52±0.67 % of PP', respectively. These results help to carry out more precise localization of the NEPs. It should provide a novel anatomical guide for improving the efficacy and efficiency of chemical neurolysis in treating thigh adductor muscle spasticity.

Aún no se pueden localizar con precisión los puntos de entrada del nervio (PEN) para el tratamiento de la espasticidad de los músculos aductores del muslo a través de la neurólisis química. El objetivo de este estudio fue identificar la ubicación y la profundidad de los PEN de los músculos aductores del muslo mediante tomografía computarizada espiral (TC) y puntos de referencia óseos. Se disecaron loa miembros inferiores de 20 cadáveres adultos en posición supina. Se trazó una línea curva en la superficie de la piel desdeel ápice del trocánter mayor del fémur hasta el centro del tubérculo púbico y se designó como línea de referencia horizontal (H). Otra línea curva desde el ápice del trocánter mayor hasta el epicóndilo lateral del fémur se designó como línea de referencia longitudinal (L). Después de la disección, los PEN se marcaron con sulfato de bario y sus puntos de proyección de la superficie del cuerpo (P) se determinaron mediante TC helicoidal. La proyección de PEN en la dirección opuesta se designó como P '. El porcentaje de ubicación de las intersecciones (PH y PL) de P con H y L y la profundidad porcentual de los PEN se determinaron con el sistema Syngo. Los PH para los PEN de los músculos pectineus, gracilis, adductor longus, aductor brevis y rama aductora del músculo aductor magnus se localizaron en 76,41±0,71 %, 93,85±2,07 %, 92,05±2,15 %, 80,75±1,20 % y 88,08±1,09 % de H, respectivamente. Los PL estuvieron en 1,64±0,04 %, 29,89±1,90 %, 16,06±1,32 %, 11,66±0,11 % y 22,94±0,90 % de la L, respectivamente. La profundidad de PEN de P puntos fue de 17,52±0,52 %, 38,38±2,75 %, 20,88±0,79 %, 20,35±0,82 % y 39,52±0,67 % de PP ', respectivamente. Estos resultados ayudan a realizar una localización más precisa de los PEN. Se debe proponer una nueva guía anatómica para mejorar la eficacia y la eficiencia de la neurólisis química en el tratamiento de la espasticidad del músculo aductor del muslo.

Anatomical Basis of the Myofascial Trigger Points of the Gluteus Maximus Muscle.

Myofascial pain syndrome is characterized by pain and limited range of motion in joints and caused by muscular contracture related to dysfunctional motor end plates and myofascial trigger points (MTrPs). We aimed to observe the anatomical correlation between the clinically described MTrPs and the entry point of the branches of the inferior gluteal nerve into the gluteus maximus muscle. We dissected twenty gluteus maximus muscles from 10 human adult cadavers (5 males and 5 females). We measured the muscles and compiled the distribution of the nerve branches into each of the quadrants of the muscle. Statistical analysis was performed by using Student's t-test and Kruskal-Wallis tests. Although no difference was observed either for muscle measurements or for distribution of nerve branching among the subjects, the topography of MTrPs matched the anatomical location of the entry points into the muscle. Thus, anatomical substract of the MTrPs may be useful for a better understanding of the physiopathology of these disorders and provide basis for their surgical and clinical treatment.

The sensory territory of the lateral cutaneous nerve of the thigh as determined by anatomic dissections and ultrasound-guided blocks.

BACKGROUND AND OBJECTIVES: A femoral block sometimes fails to provide complete sensory anesthesia of the anterior aspect of middle and distal thigh, and a block of the lateral cutaneous nerve of the thigh (LCN) is often necessary to supplement it. The goal of this study was to demonstrate, both in the anatomy laboratory and in the clinical setting, a possible contribution of the LCN to the innervation of the anterior thigh. METHODS: This was a prospective, observational study, including anatomic dissections and a clinical section in which 22 patients received an ultrasound-guided block of the LCN. The resulting area of anesthesia was determined 15 minutes later using pinprick examination. RESULTS: In 1 of 3 thigh dissections, we found a dominant LCN innervating most of the anterior aspect of the middle and distal thigh, areas that are usually attributed to the femoral nerve. In the clinical part of the study, 10 patients (45.5%) developed an area of anesthesia that extended to the medial aspect of the thigh and distally to the patella. CONCLUSIONS: Our results, coming from a small sample, seem to indicate that the LCN may contribute to the innervation of the anterior thigh in some cases. A block of the LCN could be considered when a femoral block has failed to produce the expected area of anesthesia.

A practical approach to the lateral cutaneous nerve of the thigh: an anatomical study.

OBJECTIVES: To study the main anatomical landmarks related to the lateral cutaneous nerve of the thigh (LCN) in the infrainguinal region and to define reliable criteria for identifying the nerve during the surgery and electrophysiological study. METHODS: Bilateral dissections of 60 adult non-fixed cadavers were performed with measurements of the distance between the inferior border of the anterior superior iliac spine (ASIS) and the LCN (DAL) and the internal angle between the LCN and the inguinal ligament (IA). The number of nerves exiting the inguinal ligament, the position of the LCN relative to the ASIS and to inguinal ligament were observed and registered. A triangle was designed using the inguinal ligament, the ASIS and the direction of tendinous insertions of the tensor of fascia lata muscle as parameters and the nerves were tested according its localization inside the triangle in each dissection. RESULTS: In 80% of the dissections, the LCN passed under the inguinal ligament and was identified lateral to ASIS in only three dissections. A great variability was observed in the values of DAL and IA. The values of DAL ranged from 0 (immediately medial to ASIS) to 5 cm on either side with means of 1.31 and 1.22 cm on the right and left side, respectively. The values of IA ranged from 40° to 120°, with a mean of 66.08° on the right side and from 40° to 130° with a mean of 69.92° on the left side. No significant differences were identified between the two sides with respect to the relationship between the nerve and the inguinal ligament (Chi-square test, p=0.83); DAL (t test, p=0.37) or IA (t test, p=0.15). A single nerve was found in 70.83% of the dissections. The nerve was found inside the triangle in 95% of the dissections. CONCLUSIONS: Despite the symmetry found between the right and left sides, the values of the main anatomic parameters involved in the localization of the LCN presented a great degree of variability. Even so, dissection using the proposed anatomical triangle allows for the localization of the LCN in almost all cases.

Revisión anatómica del músculo bíceps femoral del canino / Anatomical review of canine biceps femoris muscle

El músculo bíceps femoral (BF) desempeña un rol fundamental en la biomecánica del miembro pelviano de los caninos, actuando en la flexoextensión de la articulación femorotibiorotuliana y la abducción del miembro. La evaluación correcta de su función es importante en la clínica veterinaria. Existen puntos controversiales entre los autores consultados acerca de la morfología de este músculo. El presente estudio tiene como objetivo discutir las distintas descripciones, reparando en las inserciones, la estructura e inervación del músculo. Se han realizado las disecciones bilaterales en 12 animales. La conservación de las piezas se realizó por inmersión en piletas, con una dilución de formol al 10 por ciento y ácido fenico al 4 por ciento en agua. Se utilizaron diferentes técnicas de abordaje al músculo en cuestión, para obtener distintas observaciones de las estructuras. Se halló que el músculo BF se origina por medio de dos cabezas, como queda implícito en su denominación, una cabeza craneal, más voluminosa y una cabeza caudal más pequeña. La primera originada en el ligamento sacrotuberal y en la superficie lateral de la tuberosidad isquiática. La cabeza caudal, se origina de la tuberosidad isquiática. Estas partes a pesar de hallarse estrechamente unidas se individualizan a nivel de los vientres musculares por medio de una delgada lámina de tejido conectivo que se extiende hasta el tercio distal del músculo. Respecto a la inervación, no se encontraron ramas del nervio glúteo caudal que inerven las partes al músculo.

The biceps femoris (BF) muscle plays a fundamental role in the biomechanics of the canine pelvic limb, acting in flexion ­ extension on knee articulation and abduction of the limb. Correct evaluation plays an important role in veterinary clinic. There are controversial issues among the authors consulted about the morphology of this muscle. The present study aims to discuss the various descriptions proposed for this muscle, considering insertions, structure and innervation. Bilateral dissections of 12 animals were carried out. Pieces conservation was done by immersion in pools with 10 percent formaldehyde and 4 percent carbolic acid in water. Different techniques were used in order to achieve various observations of muscle structures. It was found that BF muscle originates by two heads, as is implicit in its name, a craneal head, bulkier and a smaller caudal head. The first takes origin in the sacrotuberal ligament and the lateral surface of the ischial tuberosity. The caudal head, originates from the ischial tuberosity. These parts are closely linked but they can be identified at the level of the muscle bellies through a thin layer of connective tissue that extends to the distal part of the muscle. Regarding the innervation, we found that no caudal gluteal nerve branches reach this muscle.

[Distribution of the lateral cutaneous nerve of the thigh in the area of intramuscular injection]. / Distribuição do nervo cutâneo lateral da coxa na área de injeção intramuscular.

UNLABELLED: The technique of intramuscular injection (IM) into the antero-lateral region of the thigh is widely used. Nevertheless, despite this area being indicated as the second best location for this practice, the technique is still observed to be very painful for both adult and child patients. OBJECTIVE: To study the localization, distribution and course of the lateral cutaneous nerve of the thigh, and its topographic relationship with the area recommended for the practice of intramuscular injection, relating these characteristics to the pain resulting from such procedures. METHOD: By means of exposing the antero-lateral region by classical dissection, the lateral cutaneous nerve of the thigh was identified and isolated in 20 fixed adult male cadavers, giving emphasis to the viewing of its nerve rami across the iliotibial tract. RESULTS: In 100% of the cases, the lateral cutaneous nerve emerged medially in relation to the upper anterior iliac spine. After this, it issued three wide-caliber rami in 70% of the specimens and only two in the remaining 30%. In the upper third and in the upper portion of the middle third of the thigh, a network of numerous small nerve rami was observed, enveloped in a variable quantity of adipose tissue. However, in the lower portion of the middle third of the thigh and in the lower third, no significant nerve rami were seen. CONCLUSION: Based on our data, we recommend whenever possible that the distal half of the region displayed by the classical technique be utilized as the location of choice for the practice of intramuscular injection into the antero-lateral region of the thigh. This is because this region is less innervated by the lateral cutaneous nerve of the thigh, which will cause less pain in this area during such procedures, thereby affording greater comfort to the patient.