Clinical efficacy of acupuncture combined with extracorporeal shock wave therapy in the treatment of piriformis syndrome / 中国基层医药

Objective:To evaluate the clinical efficacy of acupuncture combined with extracorporeal shock wave therapy in the treatment of piriformis syndrome.Methods:Eighty patients with piriformis syndrome who received treatment in Huaihe Energy Occupational Disease Prevention Hospital Rehabilitation Medicine Center from February 2021 to December 2022 were included in this study. They were divided into a treatment group ( n = 40) and a control group ( n = 40) according to different treatment methods using a retrospective cohort study design. The treatment group was treated with acupuncture combined with extracorporeal shock wave therapy, once every 7 days for 3 consecutive weeks. The control group was treated with extracorporeal shock wave therapy alone once every 7 days for 3 consecutive weeks.Pre- and post-treatment visual analogue scale scores and clinical efficacy were compared between the two groups. Results:There was no significant difference in baseline data between the two groups (all P > 0.05). After treatment, the visual analogue scale score decreased in each group. After adjusting for covariates, there was no significant difference in visual analogue scale score between the two groups ( F = 112.38, P < 0.001). After adjusting the pre-treatment visual analogue scale score, the post-treatment visual analogue scale score in the treatment group was lower than that in the control group [1.417 (95% CI: 1.151-1.683)]. The total response rate in the treatment group was 97.5% (39/40), which was significantly higher than 82.5% (33/40) in the control group ( Z = -2.03, P = 0.042). Conclusion:Acupuncture combined with extracorporeal shock wave therapy is highly effective on piriformis syndrome.

The absence of piriformis muscle, combined muscular fusion, and neurovascular variation in the gluteal region

The gluteal region contains important neurovascular and muscular structures with diverse clinical and surgical implications. This paper aims to describe and discuss the clinical importance of a unique variation involving not only the piriformis, gluteus medius, gluteus minimus, obturator internus, and superior gemellus muscles, but also the superior gluteal neurovascular bundle, and sciatic nerve. A routine dissection of a right hemipelvis and its gluteal region of a male cadaver fixed in 10% formalin was performed. During dissection, it was observed a rare presentation of the absence of the piriformis muscle, associated with a tendon fusion between gluteus and obturator internus, and a fusion between gluteus minimus and superior gemellus muscles, along with an unusual topography with the sciatic nerve, which passed through these group of fused muscles. This rare variation stands out with clinical manifestations that are not fully established. Knowing this anatomy is essential to avoid surgical iatrogeny.

Reporte de caso: origen del músculo piriforme a través de dos cabezas en forma de bíceps, propicia división del nervio isquiático en nervio fibular común y nervio tibial / Case report: origin of the piriformis muscle through two heads in the form of biceps, favorable division of the sciatic nerve in the common fibular nerve and tibial nerve

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.

Unilateral higher division of sciatic nerve and its clinical importance

The sciatic nerve has a long course right from the pelvis to the apex of the popliteal fossa. The point of division of the sciatic nerve into tibial and common peroneal nerves is very variable. The variation in the division of the sciatic nerve described in the present study should be helpful for anaesthetists and orthopaedic surgeons. While doing the dissection and teaching of the gluteal region in the Post Graduate Department of Anatomy, government medical college, Jammu, it was found that on the left side tibial nerve and common peroneal nerve were present instead of sciatic nerve. It meant that the main nerve that is the sciatic nerve had already been divided into its terminal branches in the pelvis region. Both tibial and common peroneal nerve were seen coming out of the pelvis below the piriformis muscle, while on the right side there were no variation. The sciatic nerve was seen coming out of the pelvis below the piriformis muscle as usual. Because of this high division of the sciatic nerve in the pelvis, there are many complications like failed sciatic nerve block during anaesthesia while performing surgery, but high division of the sciatic nerve may result in escape of either tibial nerve or common peroneal nerve. The gluteal region, back of the thigh and leg of the lower limb were dissected to study further course of tibial nerve and the common peroneal nerve. Photographs were also taken.

Sciatic nerve and its variations: is it possible to associate them with piriformis syndrome? / Nervo isquiático e suas variações: é possível associá-las à síndrome do piriforme?

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.

Piomiositis del músculo piriforme por Streptococcus pyogenes en un niño / Streptococcus pyogenes pyomyositis of the piriformis muscle in a child

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.

Accessory Belly of the Piriformis Muscle as a Cause of Piriformis Syndrome: a Case Report with Magnetic Resonance Imaging and Magnetic Resonance Neurography Imaging Findings

Piriformis syndrome caused by an accessory belly of the piriformis muscle is very rare. Only a few cases have been reported. Here, we report a case of piriformis syndrome resulting from an extremely rare type of accessory belly of the piriformis muscle originated at the proximal third portion of the main piriformis muscle and attached separately to the greater trochanter inferior to the insertion of the main piriformis muscle. A definitive diagnosis of piriformis syndrome was made based on magnetic resonance imaging and magnetic resonance neurography findings that were consistent with results of nerve conduction study and needle electromyography.

Anatomical Variations Of Sciatic Nerve Bifurcation In Human Cadavers

Background: the sciatic nerve is largest and thickest nerve in human body. It originates from L4-S3 roots of sacralplexus. It consists of 2 components namely tibial and common peroneal nerves. It passes through greater sciaticforamen and appears in the gluteal region below piriformis muscle, passes along back of the thigh and dividesinto its terminal branches viz tibial and common peroneal, near the superior angle of popliteal fossa. This pointof bifurcation into terminal branches may be variable which might be important for the clinicians.Aim: studying variations of sciatic nerve bifurcation at different levelsMaterials and methods- study conducted on 50 lower limbs, properly embalmed with formalin. The glutealregion dissected and the level of bifurcation of sciatic nerve is recorded.Results: In 42(84%) limbs the sciatic nerve terminated at the superior angle of popliteal fossa.3 limbs (6%)showed high level bifurcation in the pelvis and both branches emerged separately in infra piriform compartment.In 2 limbs (4%) sciatic nerve divided in the gluteal region. In 3(6%) limbs sciatic nerve divided in the middle of thethigh.Conclusion: knowledge of variation of sciatic nerve bifurcation helps the clinicians during intra muscularinjections, popliteal and sciatic blocks, hip surgeries.

Surgical Treatment of Piriformis Syndrome

BACKGROUND: Piriformis syndrome (PS) is an uncommon disease characterized by symptoms resulting from compression/irritation of the sciatic nerve by the piriformis muscle. Uncertainty and controversy remain regarding the proper diagnosis and most effective form of treatment for PS. This study analyzes the diagnostic methods and efficacy of conservative and surgical treatments for PS. METHODS: From March 2006 to February 2013, we retrospectively reviewed 239 patients who were diagnosed with PS and screened them for eligibility according to our inclusion/exclusion criteria. All patients underwent various conservative treatments initially including activity modification, medications, physical therapy, local steroid injections into the piriformis muscle, and extracorporeal shock wave therapy for at least 3 months. We resected the piriformis muscle with/without neurolysis of the sciatic nerve in 12 patients who had intractable sciatica despite conservative treatment at least for 3 months. The average age of the patients (4 males and 8 females) was 61 years (range, 45 to 71 years). The average duration of symptoms before surgery was 22.1 months (range, 4 to 72 months), and the mean follow-up period was 22.7 months (range, 12 to 43 months). We evaluated the degree of pain and recorded the responses using a visual analog scale (VAS) preoperatively and 3 days and 12 months postoperatively. RESULTS: Buttock pain was more improved than sciatica with various conservative treatments. Compared with preoperatively, the VAS score was significantly decreased after the operation. Overall, satisfactory results were obtained in 10 patients (83%) after surgery. CONCLUSIONS: PS is thought to be an exclusively clinical diagnosis, and if the diagnosis is performed correctly, surgery can be a good treatment option in patients with refractory sciatica despite appropriate conservative treatments.

The value of ultrasonography in the diagnosis of piriformis syndrome / 中华超声影像学杂志

Objective To discuss the diagnostic value of ultrasonography in piriformis syndrome . Methods Ultrasonography was performed in thirty‐eight patients with unilateral piriformis syndrome and forty healthy volunteers . The morphological structures and the internal echoes of their bilateral piriformises and sciatic nerves were observed and their thicknesses were measured . These parameters of the patients and voluteers were recorded and compared . Results The ultrasonographic images of piriformis and sciatic nerve of the healthy voluteers showed no abnormal change . The thickness difference of their bilateral piriformises and sciatic nerves had no statistical significance ( P > 0 .05 ) . The ultrasonography image of the morphological structure and the internal echo of the sick side piriformis and sciatic nerve of the patients with piriformis syndrome showed a change ,that the sick side piriformis was significantly thicker than the healthy side piriformis [(25 .74 ± 3 .12) mm vs (22 .48 ± 2 .60) mm , P 0 .05) . Conclusions Ultrasonography can show piriformis and sciatic nerve clearly . The ultrasonographic images and the thickness difference of the bilateral piriformises is helpful to diagnose piriformis syndrome ,and can provide more informations for clinic .

Sciatic Nerve and its Variations: An Anatomical Study.

Background and Aims: The Sciatic nerve is the widest nerve of the body, consists of two components namely tibial and common peroneal components, derived from the lumbosacral plexus from the ventral rami of L4 to S3 spinal nerves. The Sciatic nerve usually enters the gluteal region under the piriformis muscle. The purpose of this study is to identify the variations in the course and branching pattern of the sciatic nerve and its relation to the piriformis muscle which may lead to various clinical manifestations like non-discogenic sciatica. Materials and Methods: 50 gluteal regions and posterior compartment of thigh from 25 formalin fixed adult cadavers are used for this study, of which one is a female cadaver. Gluteal regions and the posterior aspect of thigh on both sides are dissected to expose the sciatic nerve. Variations in the sciatic nerve and their relationship to piriformis muscle are observed. Results: 41 gluteal regions and posterior compartments of thigh (82%) showed normal anatomy of sciatic nerve and also piriformis muscle. 9 regions (18%) showed variations in the sciatic nerve, of which 5 regions (10%) showed variation of sciatic nerve in relation to piriformis muscle. Other details are explained further in the article. Conclusion: A proper knowledge about the variations of sciatic nerve, its relation to piriformis muscle is must for medical professionals during posterior hip surgeries, sciatic nerve decompression, total hip replacement, sciatic nerve injury during deep intramuscular gluteal injections, failed sciatic nerve block during anaesthetic procedures etc.

Long-term assessment of clinical outcomes of ultrasound-guided steroid injections in patients with piriformis syndrome

PURPOSE: The purpose of this study was to evaluate the long-term efficacy of ultrasound (US)-guided steroid injections in patients with piriformis syndrome. METHODS: Between January 2010 and October 2012, 63 patients (23 men and 40 women; average age, 63.2 years; range, 24 to 90 years) were diagnosed with piriformis syndrome based on clinical history, electromyography, and flexion-adduction-internal rotation test results. They were divided into two groups. The first group (37 subjects) received a US-guided steroid injection around the piriformis muscle. The second group (26 subjects) received both piriformis muscle and spinal epidural injections. The therapeutic effect was categorized as improvement, partial improvement, or failure depending on the degree of symptom alleviation one month after injection, based on a review of each patient's medical records. RESULTS: In the first group, 15 patients (40.5%) showed improvement, seven (18.9%) showed partial improvement, and 15 (40.5%) failed to respond to the initial treatment. In the second group, eight patients (30.8%) showed improvement, 11 (42.3%) showed partial improvement, and seven (26.9%) failed to respond to the initial treatment. A second piriformis injection was performed in four cases, after which two patients showed improvement within 3 years, but the other two showed no therapeutic effect. CONCLUSION: US-guided steroid injection may be an effective treatment option for patients with piriformis syndrome.

Leg Weakness Caused by Bilateral Piriformis Syndrome: A Case Report

Piriformis syndrome (PS) is an uncommon neuromuscular disorder caused by the piriformis muscle (PM) compressing the sciatic nerve (SN). The main symptom of PS is sciatica, which worsens with certain triggering conditions. Because the pathophysiology is poorly understood, there are no definite diagnostic and therapeutic choices for PS. This case report presents a young woman who mainly complained of bilateral leg weakness. Electromyography revealed bilateral sciatic neuropathy and magnetic resonance imaging confirmed structural lesions causing entrapment of the bilateral SNs. After a laborious diagnosis of bilateral PS, she underwent PM releasing surgery. Few PS cases present with bilateral symptoms and leg weakness. Therefore, in such cases, a high level of suspicion is necessary for accurate and prompt diagnosis and treatment.

Unusual relationship between the piriform muscle and sciatic, inferior gluteal and posterior femoral cutaneous nerves / Relación inusual entre el músculo piriforme y los nervios isquiático, glúteo inferior y cutâneo femoral posterior

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.

Accessory belly of piriformis, as a cause of superior gluteal neurovascular entrapment.

During routine dissection on 50 years old male cadaver, an accessory belly of piriformis was observed. This accessory belly was superior and parallel to the main piriformis muscle. This was associated with emergence of superior gluteal nerve and superior gluteal artery between the two bellies. Piriformis muscle and its relation to sciatic nerve has been suggested as a cause of piriformis syndrome. But interestingly in the present case, superior gluteal nerve was interposed between two bellies that may help the clinicians to establish a rare yet important cause of piriformis syndrome and a rare cause of undiagnosed chronic pain in gluteal region. As superior gluteal artery was also interposed, so this rare variation holds interest to surgeons especially in isolated buttock claudication despite otherwise normal vascular investigations.

Anatomical variation of piriformis muscle as a cause of deep gluteal pain: diagnosis using MR neurography and treatment / Variação anatômica do músculo piriforme como causa de dor glútea profunda: diagnóstico por neurografia RM e seu tratamento

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.

Variaciones del Nervio Isquiático en Relación al Músculo Piriforme / Variations of the Sciatic Nerve in Relation to the Piriformis Muscle

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.

Variações anatômicas do nervo ciático em um grupo de cadáveres brasileiro / Anatomical variations of the sciatic nerve in a group of Brazilian cadavers

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.

Clinical experience in the treatment of piriformis syndrome using pulsed radiofrequency: A case report

Piriformis syndrome consists of pain, tingling sensation, and paresthesia in areas innervated by sciatic nerve and is one of the main causes of low back pain. A 43-year-old male made a visit for continuous left buttock pain and tingling sensation in lower limbs for three years. Medication, epidural block and sacroiliac joint block were performed, but without effect. Sciatic nerve block with local anesthetics and steroid, however, showed some improvement for a short period of time. The patient's symptoms, physical examination, and the fact that sciatic nerve block showed improvement for a while led to the suspicion of piriformis syndrome. Thus, pulsed radiofrequency was performed on sciatic nerve twice. Visual analog scale (VAS) was 8-9 on first visit, which decreased to 1 after treatment and lasted for more than 18 months.