Unrepaired Trochanteric Bursae as a Risk Factor for Deep Gluteal Syndrome After Total Hip Arthroplasty: A Prospective Randomized Controlled Trial.

BACKGROUND: The trochanteric bursae are often left unrepaired after total hip arthroplasty (THA) and they retract posteriorly over the muscle belly of the piriformis. Deep gluteal syndrome (DGS) is a multifactorial condition presenting as buttock pain and is attributed to nondiscogenic sciatic nerve irritation or impingement causes. The purpose of this study was to investigate the relationship between bursal repair and incidence of DGS in patients undergoing THA. METHODS: This prospective randomized trial included patients treated with a THA between January and December 2022 for a diagnosis of primary osteoarthritis. Patients were randomized into 2 groups: group 1 underwent a routine bursal repair, while group 2 did not, leaving the bursae unrepaired. Follow-up was performed on the 15th, 30th, and 90th day postoperatively with clinical scores, physical examinations, and laboratory tests. In this cohort of 104 patients, mean age was 55 years (range, 26 to 88). Demographic variables as well as range of motion and overall clinical results showed no significant difference between the groups. RESULTS: DGS rates were significantly more common in the patients who had an unrepaired bursa (group 2) both on the 30th and 90th postoperative days, while comparison of lateral trochanteric pain on palpation showed similar results between the groups. CONCLUSIONS: DGS is common in individuals who have unrepaired trochanteric bursal tissue following a THA. Despite its higher frequency, these symptoms did not have a substantial impact on the overall clinical scores, which remained consistent across the study groups.

Novel anatomical findings with implications on the etiology of the piriformis syndrome.

PURPOSE: The cause of the piriformis-related pelvic and extra-pelvic pain syndromes is still not well understood. Usually, the piriformis syndrome is seen as extra-pelvic sciatica caused by the entrapment of the sciatic nerve by the piriformis in its crossing through the greater sciatic foramen. However, the piriformis muscle may compress additional nerve structures in other regions and cause idiotypic pelvic pain, pelvic visceral pain, pudendal neuralgia, and pelvic organ dysfunction. There is still a lack of detailed description of the muscle origin, topography, and its possible relationships with the anterior branches of the sacral spinal nerves and with the sacral plexus. In this research, we aimed to characterize the topographic relationship of the piriformis with its surrounding anatomical structures, especially the anterior branches of the sacral spinal nerves and the sacral plexus in the pelvic cavity, as well as to estimate the possible role of anatomical piriformis variants in pelvic pain and extra-pelvic sciatica. METHODS: Human cadaveric material was used accordingly to the Swiss Academy of Medical Science Guidelines adapted in 2021 and the Federal Act on Research involving Human Beings (Human Research ACT, HRA, status as 26, May 2021). All body donors gave written consent for using their bodies for teaching and research. 14 males and 26 females were included in this study. The age range varied from 64 to 97 years (mean 84 ± 10.7 years, median 88). RESULTS: three variants of the sacral origin of the piriformis were found when referring to the relationship between the muscle and the anterior sacral foramen. Firstly, the medial muscle origin pattern and its complete covering of the anterior sacral foramen by the piriformis muscle is the most frequent anatomical variation (43% in males, 70% in females), probably with the most relevant clinical impact. This pattern may result in the compression of the anterior branches of the sacral spinal nerves when crossing the muscle. CONCLUSIONS: These new anatomical findings may provide a better understanding of the complex piriformis and pelvic pain syndromes due to compression of the sacral spinal nerves with their somatic or autonomous (parasympathetic) qualities when crossing the piriformis.

Deep Gluteal Syndrome: A Pain in the Buttock.

ABSTRACT: While buttock pain is a common complaint in sports medicine, deep gluteal syndrome (DGS) is a rare entity. DGS has been proposed as a unifying term referring to symptoms attributed to the various pain generators located in this region. While not all-inclusive, the diagnosis of DGS allows for focus on pathology of regionally associated muscles, tendons, and nerves in the clinical evaluation and management of posterior hip and buttock complaints. An understanding of the anatomic structures and their kinematic and topographic relationships in the deep gluteal space is pivotal in making accurate diagnoses and providing effective treatment. Because presenting clinical features may be unrevealing while imaging studies and diagnostic procedures lack supportive evidence, precise physical examination is essential in obtaining accurate diagnoses. Management of DGS involves focused rehabilitation with consideration of still clinically unproven adjunctive therapies, image-guided injections, and surgical intervention in refractory cases.

Case report and review of the potential role of the Type A piriformis muscle in dynamic sciatic nerve entrapment variant of piriformis syndrome.

Piriformis syndrome (PS) is an underdiagnosed but common cause of chronic buttock pain and sciatica. Anatomical variants of the piriformis muscle and sciatic nerve have not been thought to be significant in the pathophysiology of PS however, recent description of the piriformis musculotendinous junction has identified a common variant that we believe frequently results in dynamic sciatic nerve entrapment at the infra-piriformis fossa. We performed ultrasound guided low-dose Botulinum Toxin-A (BTX-A) injection to the lower piriformis muscle belly in an elite Australian Rules football player with PS and Type A piriformis muscle to relieve symptomatic sciatic nerve compression. Positive response to targeted BTX-A piriformis muscle injections support the hypothesis that sciatic nerve compression by Type A piriformis muscles may contribute to the pathophysiology of neuropathic PS, along with other functional factors. Sciatic nerve compression due to Type A piriformis at the infra-piriformis fossa has not been described previously and is a potentially common cause of neuropathic PS, especially when combined with other functional factors such as piriformis muscle spasm/hypertrophy and sacroiliac joint counternutation.

Endoscopic Sciatic Nerve Decompression After Fracture or Reconstructive Surgery of the Acetabulum in Comparison With Endoscopic Treatments in Idiopathic Deep Gluteal Syndrome.

OBJECTIVE: The purpose of this study was to assess the endoscopic findings of the sciatic nerve and clinical outcomes of major traumatic sciatic nerve neuropathies after fracture or reconstructive surgery of the acetabulum with idiopathic deep gluteal syndrome (DGS) groups. DESIGN: Retrospective review of patient reports. SETTING: Level I trauma center of a tertiary university hospital. PARTICIPANTS: The study included 70 patients who consecutively underwent endoscopic sciatic nerve decompression. Patients who had previous fractures or reconstructive surgeries of the acetabulum were categorized as the major trauma group, whereas those without major trauma were categorized as the idiopathic group (45 patients) after a minimum of 24-months of follow-up period. MAIN OUTCOME MEASURES: The results were evaluated using the modified Harris Hip Score (mHHS), Hip outcome, and 12-Item Short Form Health Survey scores, respectively. RESULTS: In the major trauma group, all patients with sensory symptoms showed some degree of relief after the endoscopic sciatic nerve release. None of the patients with complete foot drop demonstrated complete improvement. Three patients with motor weakness without foot drop showed complete improvement in motor function. The mean mHHS increased from 61.5 ± 13.4 to 84.1 ± 8.1 (P = 0.031). In the idiopathic DGS group, the mean mHHS increased from 73.8 ± 10.3 to 94.4 ± 5.3 (P = 0.003). The Benson outcomes rating in the major trauma group was statistically lower than that in the idiopathic DGS group. CONCLUSION: Endoscopic release of the sciatic nerve after fractures or reconstructive surgeries could provide some improvements without complications. However, more favorable outcomes were observed in the idiopathic DGS group.

The majority of piriformis muscles are innervated by the superior gluteal nerve.

The piriformis muscle is clinically implicated in pain disorders, posterior approaches for total hip arthroplasty, and iatrogenic injury to the muscle and the surrounding nerves. The piriformis muscle has been said to receive innervation from L5 to S3 ventral rami with most sources using S1 and S2 ventral rami as the most common innervation this muscle. However, descriptions of the nerve in the literature are vague. Therefore, the aim of this study was to clarify the anatomy of the nerve supply to the piriformis muscle. Twenty sides from ten fresh-frozen cadavers were studied. Specifically, via anterior dissection of the sacral plexus, branches to the piriformis were identified. Once identified, the nerves to the piriformis muscle were traced proximally to clarify their origin. Nerves supplying the piriformis muscle existed on all sides. On 80% of sides, the piriformis was innervated by two to three nerves. The origin of these nerves was from the superior gluteal nerve on 14 sides (70%), inferior gluteal nerve on one side (5%), L5 ventral ramus on one side (5%), S1 ventral ramus on 17 sides (85%), and S2 ventral ramus on 14 sides (70%), respectively. The most common nerve branches to the piriformis are from the superior gluteal nerve, and the ventral rami of S1 and S2. Based on our study, a single "nerve to piriformis" does not exist in the majority of specimens thus this term should be abandoned. Clin. Anat. 32:282-286, 2019. © 2018 Wiley Periodicals, Inc.

Myositis ossificans traumatica of the piriformis muscle: a rare mature case in an adult African male.

Myositis ossificans traumatica (MOT) is a common form of heterotopic ossification associated to trauma. Rare mature manifestations and topographically atypical presentations of MOT are often misdiagnosed as osteosarcoma. This case study discusses a rare, mature case of MOT of the piriformis muscle, potentially clinically associated with piriformis syndrome. The ossification was observed on a dry sacral bone of an adult skeleton belonging to a South African male during routine inventory of the Raymond A. Dart Collection of Human Skeletons, the University of the Witwatersrand, Johannesburg. The MOT was located on the anterior aspect of the sacrum at a site corresponding to the upper portion of the origin of the muscle and extended laterally towards the greater trochanter, beyond the greater sciatic notch. It was cylindrical in shape and measured approximately 52.70 mm in length and 12.10 mm in diameter. Micro-focus CT revealed an extensive and mature bony development of the piriformis muscle with distinct outer cortical and inner trabecular bone. In addition, the skeleton showed widespread healed skeletal trauma, suggesting a history of trauma. The MOT was completely fused to the sacral bone excluding the possibility of congenital anomalies. Information on the MOT of the piriformis muscle is vital to clinicians and radiographers to aid in successful diagnosis and management of the piriformis syndrome and sciatica in the gluteal region. This case also provides a rare example to biological anthropologists, paleoanthropologists and bioarchaeologists of the representation of pathologies like these on a dry bone sample.

Piriformis syndrome: a case series of 31 Bangladeshi people with literature review.

AIMS: To describe a series of piriformis syndrome patient among Bangladesh people with literature review. METHODS: Consecutive 31 piriformis syndrome patients were enrolled. Besides history and clinical examination, piriformis muscle thickness was also measured with diagnostic ultrasound (3.5 MHZ). MRI of lumbar spine, X-rays of lumbo-sacral spine, and pelvis were performed in all patients. Statistical Package for the Social Sciences (SPSS), Windows 8.0, was used for statistical calculation, and univariate analysis of primary data was done. Data present with frequency table. For literature review concerning piriformis syndrome we used Embase, Pubmed, Medline, and Cochrane database. RESULTS: A total of 31 patients (21 female) with PS were enrolled, 21 housewives. Mean age 42.2 ± 14.5 years. All presented with buttock pain, aggravating with long sitting (31), lying on the affected side (31), during rising from a chair(24), and forward bending (28). Six reported pain improvement while walking. Gluteal tenderness, positive FAIR test, and Pace sign were elicited in all patients. A palpable gluteal mass was found in 8 cases, gluteal atrophy in 5 other patients. The mean piriformis muscle thickness on the diseased side was more than on the healthy side (13.6 ± 3.7 vs 10.9 ± 1.9, (p > 0.05). Common conditions associated with PS were: preceding fall (9, 29 %), overuse of piriformis muscle, lumbar spinal stenosis, fibromyalgia, intra-muscular gluteal injection, blunt trauma over the buttock, leg length discrepancy and use of rear pocket's wallet. CONCLUSIONS: In Bangladesh piriformis syndrome is more common in female, especially among housewives. A fall often precedes the condition. Piriformis syndrome should be considered as possible diagnosis when sciatica occurs without a clear spine pathology.

Clinical results of endoscopic sciatic nerve decompression for deep gluteal syndrome: mean 2-year follow-up.

BACKGROUND: The purpose of this study is to assess the effectiveness of endoscopic sciatic nerve decompression and evaluated the differences of clinical results between atraumatic and traumatic groups. METHODS: Sixty consecutive patients. We retrospectively reviewed sixty consecutive patients without major trauma (45 hips) or with major trauma (15 hips) groups to compare the outcomes of endoscopic treatment.). The mean follow-up period was 24 ± 2.6 months (range, 24-38.4 months). RESULTS: The mean duration of symptoms was 14.1 months (range, 12 to 32 months). Compromising structures were piriformis muscle, fibrovascular bundles, and adhesion with scar tissues. The mean VAS score for pain decreased from 7.4 ± 1.5 to 2.6 ± 1.5 (P = .001). The mean mHHS increased from 81.7 ± 9.6 to 91.8 ± 7.6 (P = .003). Clinically, positive paresthesia and seated piriformis test were statistically significant to diagnosis sciatic entrapment syndrome. Paresthesia and sitting pain were significantly improved at the final follow-up (P = .002). More favorable outcome was observed a group without major trauma. No complication was observed. CONCLUSIONS: Endoscopic sciatic nerve decompression is a safe and effective procedure for the management of DGS. Patients with major trauma could have poor clinical outcome. Seated piriformis test, FADIR, and tenderness of sciatic notch are maybe useful guide for pre and postoperative evaluation of DGS.

Intrapiriformis lipoma: an unusual cause of piriformis syndrome.

INTRODUCTION: We report on a patient with an unusual cause of non-discogenic sciatica. MATERIAL AND METHODS: A 48-year-old woman presented with a 10-day history of gradually worsening left buttock pain radiating to the ipsilateral posterior thigh and calf. She had a similar episode of less intense pain 8 months before which lasted about 2 months. She denied any history of antecedent trauma or back pain. MRI scan revealed a well-defined, fat-containing lesion of the left piriformis muscle similar to a lipoma displacing the sciatic nerve but not invading it. The sciatica was relieved after excision of the lesion. The patient remained asymptomatic after the operation. CONCLUSION: The present case suggested that an intrapiriformis lipoma can cause secondary piriformis syndrome and medical practitioners should be aware of this condition and consider lipomas and other occupying lesions of the pelvic muscles as a differential diagnosis in patients presenting with radicular pain.

Prevalence of piriformis syndrome in chronic low back pain patients. A clinical diagnosis with modified FAIR test.

PURPOSE: Piriformis syndrome is a collection of symptoms and signs of pain from piriformis muscle and is characterized by pain in buttock with variable involvement of sciatic nerve. This syndrome is often overlooked in clinical practice because its presentation has similarities with other spine pathologies. A major problem with the clinical diagnosis of piriformis syndrome is the lack of consistent objective findings and an absence of single test that is specific for piriformis syndrome. Therefore, a precise and reliable clinical method of diagnosing piriformis syndrome should be developed by clinicians. METHODS: This is a prospective observational study involving 93 consecutive patients who attended the pain management unit for chronic low back pain. The diagnosis of piriformis syndrome was made using the modified flexion adduction internal rotation (FAIR) test, which is a combination of Lasègue sign and FAIR test. Prevalence of piriformis syndrome based on this technique was compared with the previous data using other techniques. Chi square (χ2) analysis was performed to detect the relationship between piriformis syndrome and the potential risk factors. RESULTS: On the basics of our diagnostic criteria, the prevalence of piriformis syndrome was 17.2% among low back pain patients. All the patients diagnosed with piriformis syndrome responded well with piriformis muscle injections. No significant associations were detected between piriformis syndrome and spine disorders. CONCLUSIONS: Piriformis syndrome is a painful condition that is often overlooked in the differential diagnosis of chronic buttock or low back pain. The modified FAIR test together with piriformis muscle injection is potentially a reliable method for the clinical diagnosis of piriformis syndrome.

[Piriformis muscle syndrome: etiology, pathogenesis, clinical manifestations, diagnosis, differential diagnosis and therapy]. / Sindrom misica piriformisa: etiologija, patogeneza, klinicke manifestacije, dijagnoza, diferencijalna dijagnoza i terapija.

The term 'piriformis syndrome' (PS), introduced by Robinson in 1947, implies a group of signs and symptoms caused by piriformis muscle (PM) disorders. Since PM disorders lead to irritation/compression of the anatomic structures passing under its belly, the main clinical PS signs and symptoms are actually the clinical signs and symptoms of irritation/ compression of neural and vascular structures passing through the infrapiriform foramen: sciatic nerve/SN, inferior gluteal nerve, posterior femoral cutaneous nerve, pudendal nerve, inferior gluteal artery and vein and inferior pudendal artery and vein. The clinical picture is usually dominated by signs and symptoms of irritation/compression of SN (SN irritation --> low back and buttock pain, sciatica,paresthesias in distribution of SN; SN compression --> low back and buttock pain,sciatica, paresthesias and neurologic deficit in distribution of SN). Irritation/compression of other structures can result in the following signs and symptoms: inferior gluteal nerve --> atrophy of gluteal muscles; posterior femoral cutaneous nerve --> pain, paresthesias and sensory disturbances in the posterior thigh; pudendal nerve --> pudendal neuralgia, painful sexual intercourse (dyspareunia), sexual dysfunction, urination and defecation problems; inferior gluteal artery --> ischemic buttock pain; inferior pudendal artery --> ischemic pain in the area of external sex organs, perineum and rectum, sexual dysfunction, urination and defecation problems; inferior gluteal vein --> venous stasis in gluteal area; inferior pudendal vein --> venous stasis in external sex organs and rectum. Functional/non-organic and organic PM disorders can cause PS: spasm, shortening, hypertrophy, anatomic variations, edema, fibrosis, adhesions, hematoma, atrophy, cyst, bursitis, abscess, myositis ossificans, endometriosis, tumors (functional disorders: PM spasm and shortening). The most common causes for PS are PM spasm, shortening and hypertrophy and anatomic variations of PM and SN. In 5-6% of patients with low back pain and/or unilateral sciatica, the pain is caused by PM disorders. PS diagnosis can be made on the basis of anamnesis, clinical picture, clinical examination, EMNG, perisciatic anesthetic block of PM and radiological exams (pelvis/PM MRI; MR neurography of LS plexus and SN). PS therapy includes medicamentous therapy, physical therapy, kynesitherapy, acupuncture, therapeutic perisciatic blocks, botulinum toxin injections and surgical treatment (tenotomy of PM, neurolysis of SN).

Deep Gluteal Pain Syndrome: Endoscopic Technique and Medium-Term Functional Outcomes.

BACKGROUND: Sciatic nerve entrapment is an entity that generates disabling pain, mainly when the patient is sitting on the involved side. According to some studies, the presence of fibrovascular bands has been described as the main cause of this pathology, and the sciatic nerve's decompression by endoscopic release has been described as an effective treatment generally associated with a piriformis tenotomy. The aim of this study was to present the medium-term functional results of endoscopic release of the sciatic nerve without resection of the piriformis tendon. METHODS: This prospective, observational study included 57 patients who underwent an endoscopic operation for sciatic nerve entrapment between January 2014 and January 2019. In all cases, a detailed medical history was obtained and a physical examination and a functional evaluation were performed using the modified Harris hip score (mHHS), the 12-item International Hip Outcome Tool (iHOT-12), and the visual analog scale (VAS) for pain. All patients had pelvic radiographs and magnetic resonance imaging (MRI) scans of the hip on the involved side and underwent a prior evaluation by a spine surgeon. RESULTS: This study included 20 male and 37 female patients with a mean age of 43.6 years (range, 24 to 88 years) and a mean follow-up of 22.7 months. The median mHHS improved from 59 to 85 points. The median iHOT-12 improved from 60 to 85 points. The median VAS decreased from 7 to 2. Postoperative complications occurred in 12% of patients: 1 patient with extensive symptomatic hematoma, 3 patients with hypoesthesia, and 3 patients with dysesthesia. CONCLUSIONS: Endoscopic release of the sciatic nerve by resection of fibrovascular bands without piriformis tenotomy is a technique with good to excellent functional results comparable with those of techniques in the literature incorporating piriformis tenotomy. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Injection site pseudosarcoma in piriformis syndrome.

AIMS: Pseudosarcomatous reactive myofibroblastic proliferations have been described following surgery or trauma at a variety of anatomical sites. These types of reactions have not been previously described at injection sites. Here we evaluated prevalence, morphologic patterns and clinical resolution of such lesions. METHODS AND RESULTS: We analyzed 266 surgical resection specimens obtained during the definitive treatment of piriformis syndrome. Three cases showed exuberant reactive fibroblastic/myofibroblastic intramuscular proliferations, mimicking a sarcoma. In all three cases the surgeries were found to be preceded by local injections of cortisone and bupivacaine. Clinical follow-up revealed no uncontrolled growth. CONCLUSIONS: As the clinical history of injections is often not provided, it is important to be aware of this pitfall when reviewing skeletal muscle resections for entrapment syndromes.

Diffuse large B-cell lymphoma presenting as piriformis syndrome.

Piriformis syndrome (PS) is a rare condition characterized by pain and paresthesia of the buttock, often radiating to the posterior thigh. A patient with sciatica that was clinically suspicious for PS, underwent diagnostic work-up. A diagnosis of diffuse large B-cell lymphoma with neurolymphomatosis (NL) was made. To our knowledge, this is the first report of NL presenting as PS. NL is a possible cause of secondary PS.

Arthroscopic treatment of piriformis syndrome by perineural cyst on the sciatic nerve: a case report.

This is a case report of an arthroscopic treatment performed on a patient with piriformis syndrome due to perineural cyst on piriformis muscle and sciatic nerve. Confirmation, incision, and drainage of benign cystic lesion on the sciatic nerve below the piriformis muscle were performed following the release of the piriformis tendon through the posterior and posteroinferior arthroscopic portal. Recurrence of the symptoms has not been observed since postoperative period of 20 months. Nor did the MRI taken after the procedure reveal any such recurrence.

[Piriformis syndrome]. / Syndrome du muscle piriforme.

Sciatic pain is often misleading and establishing the link with a local muscular cause can be difficult and lead to errors, especially when faced with a young sportsman, with typical discogenic pain. Simple, specific and reproducible tests enable a better identification and treatment of a muscular cause or canal syndrome. Physiotherapy, or local infiltrations are generally very efficient, and sufficient. Surgery may be considered only in a very limited number of cases, lack of response to the first line treatment and then only if it is the absolute diagnosis, diagnosis which must remain a diagnosis of exception, more so of exclusion.

Piriformis Pyomyositis Presenting as Migratory Hip to Knee Pain: A Case Report.

CASE: The authors report a case of piriformis pyomyositis in a teenage female patient with fever and left hip pain. Her pain migrated to the knee with concurrent near resolution of hip pain. Imaging revealed an abscess in the left piriformis with pus tracking along the sciatic nerve sheath. This was complicated by internal iliac vein thrombosis and an embolus to the lung. Open drainage was performed, followed by outpatient intravenous cloxacillin and oral warfarin, with complete resolution of symptoms. CONCLUSION: Piriformis pyomyositis is a rare condition with varying presentations. The threshold for suspicion should be low even in healthy young individuals.

Sciatic nerve and its variations: is it possible to associate them with piriformis syndrome?

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.