ABSTRACT
El músculo piriforme es un músculo pelvitrocantérico que recibe su nombre debido a su forma de pera, cuyo origen es de varios fascículos que se encuentran entre los forámenes anteriores del sacro, correspondiente a las segunda, tercera y cuarta vértebra. Estos fascículos se funden constituyendo un músculo aplanado, que se inserta en el trocánter mayor del fémur. Presenta una relación bien conocida con el nervio isquiático, el cual comúnmente emerge hacia la región glútea por el margen inferior de este músculo, sin embargo a través del tiempo, autores han descrito variaciones del paso de este nervio que podrían asociarse a alguna patología de compresión del nervio isquiático. En una disección rutinaria de dos individuos formolizados, uno femenino y otro masculino de la región glútea, encontramos que el músculo piriforme se originaba a través de dos cabezas, cada una con su propia fascia que se unían en un vientre común, en forma de bíceps y a través de un tendón cilíndrico se insertaban en la parte medial del trocánter mayor del fémur. El nervio isquiático se encontraba dividido, el nervio fibular común emergía a la región glútea a través de las cabezas, en tanto el nervio tibial por el margen inferior del músculo piriforme. Es importante comunicar las variaciones anatómicas para complementar el conocimiento de las mismas, las que pueden explicar ciertos trastornos físicos y dolorosos como el denominado síndrome del músculo piriforme.
The piriform muscle is a pelvitrochanteric muscle that gets its name due to its pear shape, whose origin are several fascicles located between the anterior foramina of the sacrum, corresponding to the second, third and fourth vertebrae. These fascicles are fused forming a flattened muscle, which is inserted into the greater trochanter of the femur. It has a well-known relationship with the sciatic nerve, which commonly emerges towards the gluteal region through the lower margin of this muscle, however over time, authors have described variations in the course of this nerve that could be associated with some compression pathology of the sciatic nerve. In a routine dissection of two formalized individuals, one female and one male, we found that the piriformis muscle originated through two heads, each with its own fascia that joined in a bicep-shaped common belly. Through a cylindrical tendon it is inserted into the medial part of the greater trochanter of the femur. The sciatic nerve was divided, the common fibular nerve emerged to the gluteal region through the heads, while in the tibial nerve divided through the inferior margin of the piriformis muscle. It is important to report on the anatomical variations to complement knowledge of these variations, which may explain certain physical and painful disorders such as the socalled piriformis muscle syndrome.
Subject(s)
Humans , Male , Female , Sciatic Nerve/anatomy & histology , Buttocks/anatomy & histology , Piriformis Muscle Syndrome/pathology , Cadaver , Anatomic VariationABSTRACT
ABSTRACT The sciatic nerve forms from the roots of the lumbosacral plexus and emerges from the pelvis passing inferiorly to the piriformis muscle, towards the lower limb where it divides into common tibial and fibular nerves. Anatomical variations related to the area where the nerve divides, as well as its path, seem to be factors related to piriformis syndrome. Objective: To analyze the anatomical variations of the sciatic nerve and its clinical implications. Methods: This was a systematic review of articles indexed in the PubMed, LILACS, SciELO, SpringerLink, ScienceDirect and Latindex databases from August to September 2018. Original articles covering variations of the sciatic nerve were included. The level of the sciatic nerve division and its path in relation to the piriformis muscle was considered for this study. The collection was performed by two independent reviewers. Results: At the end of the search, 12 articles were selected, characterized according to the sample, method of evaluation of the anatomical structure and the main results. The most prevalent anatomical variation was that the common fibular nerve passed through the piriformis muscle fibers (33.3%). Three studies (25%) also observed anatomical variations not classified in the literature and, in three (25%) the presence of a double piriformis muscle was found. Conclusion: The results of this review showed the most prevalent variations of the sciatic nerve and point to a possible association of this condition with piriformis syndrome. Therefore, these variations should be considered during the semiology of disorders involving parts of the lower limbs.
RESUMO O nervo isquiático forma-se a partir das raízes do plexo lombosacro e emerge da pelve passando inferiormente ao músculo piriforme, em direção ao membro inferior onde se divide em nervos tibial e fibular comum. Variações anatômicas relativas ao local onde ocorre a divisão desse nervo, bem como do seu trajeto, parecem ser fatores relacionados à síndrome do piriforme. Objetivo: Analisar as variações anatômicas do nervo isquiático e suas implicações clínicas. Materiais e Métodos: Trata-se de uma revisão sistemática de artigos indexados nas bases de dados PubMed, LILACS, SciELO, SPRINGERLINK, SCIENC DIRECT e LATINDEX. Foram incluídos artigos originais envolvendo as variações do nervo isquiático. Considerou-se para este estudo o nível de divisão do nervo isquiático e o seu trajeto em relação ao músculo piriforme. A coleta foi realizada por dois revisores independentes. Resultados: Ao final da busca foram selecionados 12 artigos, caracterizados quanto à amostra, método para avaliar a estrutura anatômica e principais resultados. A variação anatômica mais prevalente foi aquela em que o nervo fibular comum atravessa as fibras do músculo piriforme (33,3%). Três estudos (25%) observaram, ainda, variações anatômicas não classificadas na literatura e em outros três (25%) constatou-se a presença de um músculo piriforme duplo. Conclusão: Os resultados desta revisão mostram as variações mais prevalentes do nervo isquiático e apontam para uma possível associação dessa condição com a síndrome do piriforme. Desse modo, essas variações devem ser consideradas durante a semiologia dos distúrbios envolvendo os membros inferiores.
Subject(s)
Humans , Male , Female , Sciatic Nerve/anatomy & histology , Piriformis Muscle Syndrome/pathology , Piriformis Muscle Syndrome/etiology , Anatomic Variation , Medical IllustrationABSTRACT
La piomiositis aguda es una infección supurativa del músculo esquelético. El agente etiológico más frecuente es Staphylococcus aureus, y son infrecuentes los casos producidos por Streptococcus pyogenes. Las localizaciones más habituales son cuádriceps, glúteos e iliopsoas; es excepcional la afectación del músculo piriforme. Se presenta el caso de un varón de 8 años, previamente sano, que fue ingresado en nuestro hospital por una piomiositis aguda por Streptococcus pyogenes localizada en el músculo piriforme. El diagnóstico y el inicio precoz del tratamiento antibiótico permitieron el manejo conservador del cuadro y no fue necesaria la cirugía. La evolución fue satisfactoria y no presentó secuelas.
Acute pyomyositis is a suppurative infection of the skeletal muscle. Staphylococcus aureus is the most frequent etiological agent. Cases produced by Streptococcus pyogenes are uncommon. The most usual locations are quadriceps, buttocks and iliopsoas. The involvement of the piriformis muscle is very exceptional. We present the case of a previously healthy 8-year-old male who was admitted to our hospital for acute pyomyositis caused by Streptococcus pyogenes located in the piriformis muscle. Early diagnosis and prompt initiation of antibiotic treatment allowed the conservative management of the condition, and surgery was not necessary. The evolution was satisfactory without sequels.
Subject(s)
Humans , Male , Child , Sciatica , Streptococcus pyogenes , Pyomyositis , Piriformis Muscle SyndromeABSTRACT
Introducción: El síndrome del músculo piramidal constituye el conjunto de signos y síntomas originados por la compresión del nervio ciático en su salida de la pelvis a través del canal situado entre el músculo piramidal y el gémino superior. Se presenta una serie de casos de pacientes oncológicos con este síndrome con el objetivo de describir el resultado terapéutico de la infiltración con esteroides en el músculo piramidal sin hidrodisección perineural del ciático. Métodos: Se realizó un estudio prospectivo de 10 casos, evaluados entre Febrero de 2014 y Mayo del 2015, en el servicio de dolor y cuidados paliativos del Instituto Oncológico Nacional "Dr. Juan Tanca Marengo"-Solca-Guayaquil. Ingresaron al estudio pacientes con cáncer de cualquier etiología y criterios diagnósticos de síndrome piramidal. Los pacientes fueron tratados con infiltraciones de corticoides sin hidrodisección perineural del ciático, dirigidas por ultrasonido del músculo piramidal afecto y terapia física. Resultados: Se incluyen 10 casos de pacientes con síndrome piramidal (9 mujeres). Con rangos de edad que entre 50 y 70 años. El lado afectado con mayor frecuencia fue el derecho en 5 casos. En 8 casos la Resonancia magnética fue normal y en 2 casos se describió hipertrofia muscular. El procedimiento de infiltración se realizó sin complicaciones y los pacientes recibieron adicionalmente fisioterapia. El EVA inicial fue > 6 en 8 pacientes y 2 casos con EVA de 5. Los pacientes tuvieron una limitación funcional de un 10-20 %. El EVA postbloqueo disminuyó hasta 0-1 en todos los casos. Conclusión: En la presente serie de casos el síndrome piramidal fue controlado satisfactoriamente con infiltración de esteroides sin hidrodisección perineural del ciático y terapia física.
Introduction: Pyramidal muscle syndrome is a signs and symptoms set caused by sciatic nerve compression and its exit from the pelvis through the channel between the pyramidal muscle and the superior genus. We present a series of cases of oncological patients with this syndrome with the aim of describing the therapeutic result of steroid infiltration in the pyramidal muscle without perineural hydrodissection of the sciatic nerve. Methods: A prospective study of 10 cases, evaluated between February 2014 and May 2015, in the pain and palliative care service of the National Oncological Institute "Dr. Juan Tanca Marengo "-SolcaGuayaquil. Patients with cancer of any etiology and diagnostic criteria of pyramidal syndrome entered the study. The patients were treated with corticosteroid infiltrations without perineural hydrodissection of the sciatic nerve, directed by pyramid-shaped muscle ultrasound and physical therapy. Results: Ten cases of patients with pyramidal syndrome (9 women) are included. With age ranges between 50 and 70 years. The most affected side was the right in 5 cases. In 8 cases the magnetic resonance was normal and in 2 cases muscle hypertrophy was described. The infiltration procedure was completed without complications and the patients received additional physiotherapy. The initial EVA was> 6 in 8 patients and 2 cases with VAS of 5. The patients had a functional limitation of 10-20%. The post-blocking EVA decreased to 0-1 in all cases. Conclusion: In the present series of cases the pyramidal syndrome was successfully controlled with steroid infiltration without perineural hydrodissection of the sciatic and physical therapy.
Subject(s)
Humans , Male , Female , Middle Aged , Aged , Sciatica , Infiltration-Percolation , Piriformis Muscle Syndrome , Pain , Ultrasonography, Interventional , NeoplasmsABSTRACT
Piriformis muscle syndrome has been increasingly recognized as a cause of leg pain. Overuse, strain, or anatomical variations of the relationship between the nerve and the piriformis muscle are thought to be the underlying causes of the entrapment of the sciatic nerve. We report a variation not previously described which was found during a routine dissection. During routine dissection of the left gluteal region of an adult male cadaver we observed a high division of the sciatic nerve and the presence of an accessory piriformis muscle. The sciatic nerve divided beneath the piriformis muscle and the common fibular nerve passed over the accessory piriformis muscle, whereas the tibial nerve reflected anteriorly to pass between the accessory piriformis and the superior gemellus muscle. Additionally, both nerves communicated with a side branch under the inferior border of the accessory piriformis muscle and the inferior gluteal nerve originated from the fibular nerve. Anatomical variations in the relationship between the piriformis muscle and the sciatic nerve may be present in up to 17% of the population. Six different variations have been described and none of them is similar to our description. Though complete understanding of the physiopathology of the piriformis muscle syndrome remains to be elucidated, knowledge of the possible anatomical variations may be useful for its adequate diagnosis and treatment.
El síndrome del músculo piriforme se ha reconocido cada vez más como una causa de dolor en los miembros inferiores. Tensión excesiva o variaciones anatómicas del nervio y del músculo piriforme se cree son las causas subyacentes de pinzamiento del nervio isquiático. Se presenta una variación no descrita anteriormente. Durante una disección de rutina en un cadáver de sexo masculino, se observó una división más alta del nervio isquiático y la presencia de un músculo piriforme accesorio. El nervio isquiático se dividía bajo el músculo piriforme y el nervio fibular común pasaba sobre el músculo piriforme accesorio. Por otra parte, el nervio tibial cruzaba entre los músculos piriforme accesorio y gemelo superior. Además, ambos nervios se comunicaban con un ramo lateral bajo el margen inferior del músculo piriforme accesorio y el nervio glúteo inferior se originaba desde el nervio fibular. Variaciones anatómicas y relaciones entre el músculo piriforme y nervio isquiático pueden estar presentes hasta en el 17% de la población. Seis variaciones diferentes se han descrito en este artículo y ninguna es similar a nuestra descripción. A pesar del completo entendimiento de la fisiopatología del síndrome del músculo piriforme, aún queda por esclarecer y conocer las posibles variaciones anatómicas que pueden ser útiles tanto para su diagnóstico como para el tratamiento adecuado.
Subject(s)
Humans , Male , Middle Aged , Sciatic Nerve/abnormalities , Muscle, Skeletal/abnormalities , Anatomic Variation , Buttocks/innervation , Cadaver , Muscle, Skeletal/innervationABSTRACT
Female patient, 42 years old with a history of low back pain on the left for seventeen years in which the definitive diagnosis of the etiology of pain was evident after the completion of neurography magnetic resonance imaging of the sciatic nerve. In this test it was identified the presence of an anatomical variation in the relationship between the piriformis muscle and sciatic nerve. We discuss details of this imaging technique and its importance in the frames of refractory low back pain. We also describe the treatment given to the case. .
Paciente do sexo feminino, 42 anos, com histórico de lombociatalgia à esquerda havia 17 anos. O diagnóstico definitivo da etiologia da dor só foi evidenciado após a neurografia por ressonância magnética do ciático. Nesse exame identificou-se a presença de variação anatômica entre o músculo piriforme e o nervo ciático. Descrevemos detalhes sobre a técnica de imagem e sua importância nos quadros de lombociatalgia refratária, como também o tratamento instituído para o caso.
Subject(s)
Humans , Female , Middle Aged , Magnetic Resonance Imaging , Piriformis Muscle Syndrome/diagnosis , Piriformis Muscle Syndrome/rehabilitationABSTRACT
El nervio isquiático nace del plexo sacro y sale de la pelvis a través del foramen isquiático mayor por debajo del musculo piriforme como un tronco común. En ocasiones, este nervio puede emerger dividido en sus dos componentes: el nervio fibular común y nervio tibial, encontrándose, variaciones que podrían dar origen a una condición de compresión nerviosa. En este trabajo se exponen dos variaciones del nervio isquiático en un mismo individuo, donde en la primera el nervio fibular común atraviesa el músculo piriforme y luego desciende junto al nervio tibial y la segunda, donde el nervio fibular común se forma a partir de un ramo superior que perfora el músculo piriforme y el otro inferior que pasa debajo de él, para unirse luego en el margen inferior de éste músculo y formar el nervio fibular común, que desciende junto al nervio tibial. Las variaciones del nervio isquiático en relación al músculo piriforme podrían explicar el síndrome del músculo piriforme.
The sciatic nerve arises from the sacral plexus and exits the pelvis through the greater sciatic foramen below the piriformis muscle as a common trunk. Sometimes this nerve can emerge divided into two components: the common fibular nerve and tibial nerve, finding variations that could give rise to a condition of nerve compression. In this paper we describe two variations of the sciatic nerve in the same individual, where in the first common fibular nerve passes through the piriformis and then descends along the tibial nerve and the second, where the common fibular nerve is formed from a higher branch that pierce to piriform muscle and a lower branch passing under him, then join at the inferior margin of this muscle and form the common fibular nerve, which descends with the tibial nerve. Variations of the sciatic nerve in relation to the piriformis muscle could explain the piriformis syndrome.
Subject(s)
Humans , Male , Adult , Sciatic Nerve/anatomy & histology , Muscle, Skeletal/anatomy & histology , Anatomic Variation , Cadaver , Piriformis Muscle SyndromeABSTRACT
JUSTIFICATIVA E OBJETIVOS: O nervo ciático está frequentemente envolvido em situações de dor. É um nervo longo, propenso a lesões que podem ser consequência de trauma, inflamação e aprisionamento. Um causa possível de dor ciática deriva do músculo piriforme, que mantém estreita relação anatômica com o nervo ciático. O objetivo do presente estudo foi avaliar as características do nervo ciático e de sua relação com o músculo piriforme em um grupo de cadáveres brasileiros.MÉTODO: Dissecção anatômica de 40 membros inferiores com estudo detalhado do nervo ciático e do músculo piriforme.RESULTADOS: As variações de relação anatômica entre o nervo ciático e o músculo piriforme foram raras.Dados de comprimento e largura do nervo ciático foram semelhantes àqueles descritos na literatura.CONCLUSÃO: A síndrome do piriforme é uma condição dolorosa, considerada por muitos como sendo relacionada às variações anatômicas entre o nervo ciático e o músculo piriforme. A raridade de tais variações, tanto no presente estudo como em publicações por outros grupos,sugere que a síndrome dolorosa possa ocorrer frequentementes sem que existam variações anatômicas.
BACKGROUND AND OBJECTIVES: The sciatic nerveis often involved in conditions of pain. It is a long nerve, prone to injuries that are the consequence of trauma,inflammation and entrapment. One possible cause of sciatic pain derives from the piriformis muscle, which maintains a very close anatomical relationship with the sciatic nerve. The objective of the present study was to evaluatethe characteristics of the sciatic nerve and its relationship to the piriformis muscle in a group of Brazilian cadavers. METHOD: Anatomical dissection of 40 human limbs with detailed studies of the sciatic nerve and the piriformis muscle.RESULTS: Anatomical variations of the relationship between the sciatic nerve and the piriformis muscle were rare. Data on the sciatic nerve length and width showed similar results to those from the literature.CONCLUSION: The piriformis syndrome is a painful condition considered by many to be associated to anatomical variations of the relationship between the sciatic nerve and the piriformis muscle. The rarity of such variations,in the present series and in the studies published by other groups, suggests that the painful syndrome may often occur without the anatomical variations.