Does piriformis muscle syndrome impair postural balance? A case control study.

BACKGROUND AND PURPOSE: While patients with musculoskeletal disorders reported postural balance impairments, it is unknown whether patients with piriformis muscle syndrome (PMS) may exhibit postural balance disorders compared to controls. The aim was to compare postural balance in patients with PMS to controls in static and dynamic conditions. MATERIAL AND METHODS: Twelve patients with PMS and twelve controls were enrolled. Static postural balance was assessed by calculating the symmetry index (SI) in the unipedal posture. To measure vision contribution, the Romberg index (RI) was computed. Dynamic postural balance was evaluated with the Timed up and go test (TUGT). Besides, inter-limb strength asymmetry (SA), pain and the short form-36 (SF-36) were assessed. RESULTS: The PMS group (PMSG) exhibited significant (p < 0.001) higher SI in eyes opened (EO) and eyes closed (EC) conditions compared to the control group (CG). Besides, PMSG had significant higher RI (p < 0.05), TUGT scores (p < 0.001), SA values (p < 0.05), pain intensity (p < 0.001), and worse SF-36 scores on all physical health (p < 0.05) and psychological health (only in vitality and mental health [p < 0.05]), compared to CG. CONCLUSION: Our data revealed impaired static and dynamic postural balance, and reduced quality of life in PMSG compared to CG. Postural balance impairments could explain the poor quality of life, which are likely due to the higher SA and higher pain intensity. Clinicians and physiotherapists should consider postural balance disorders while designing rehabilitation programs in these patients.

Pressure Pain Threshold in Subjects With Piriformis Syndrome: Test-Retest, Intrarater, and Interrater Reliability, and Minimal Detectible Changes.

OBJECTIVE: This study aimed to assess the test-retest, intrarater, and interrater reliability of using the pressure pain threshold (PPT) in healthy and affected piriformis muscles and to estimate its absolute reliability. As a secondary objective, the degree of tenderness of the affected piriformis muscles was compared with healthy piriformis muscles. STUDY DESIGN: This study used a comparative and reliability-based design. SETTING: Rehabilitation clinic. PARTICIPANTS: Patients (N=30) with unilateral piriformis muscle syndrome (30 affected and 30 healthy piriformis muscles) were recruited, and the PPT of both the healthy and affected piriformis muscles was recorded using digital algometry. Measurements of PPT were done by 2 raters (rater 1 and 2), which were selected at random order. Rater 1 repeated the PPT measurements 24-72 hours after initial assessment. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: PPT. RESULTS: Excellent intrarater intraclass correlation coefficient (ICC) values were observed for the PPT of the affected piriformis (ICC: 0.86-0.96) and the healthy piriformis (ICC: 0.88-0.96) in the same session. The PPT measurements using digital algometry showed good-to-excellent interrater reliability (ICC: 0.64-0.92) and test-retest reliability (ICC: 0.72-0.95) in both the healthy and affected piriformis muscles. The findings revealed a significant decrease in the PPT of the affected piriformis muscle in comparison to the healthy piriformis muscle (mean difference 12.76; 95% confidence interval, 15.69-9.82; P<.001). CONCLUSIONS: Digital algometry is a reliable tool for measuring piriformis PPT, regardless of the testing session and the rater. Patients with unilateral piriformis muscle syndrome have increased tenderness and decreased PPT in the affected piriformis muscle in comparison to the healthy piriformis muscle.

Ultrasound-guided dry needling decreases pain in patients with piriformis syndrome.

INTRODUCTION: Piriformis muscle syndrome (PMS) is a disorder that can lead to symptoms of buttock pain and limited hip-joint mobility, and may have an impact on quality of life. METHODS: Thirty-two patients with PMS were randomized to the treatment group, which included three sessions of ultrasound-guided dry needling (DN) of the piriformis muscle (n = 16), or a waitlist control group (n = 16). The primary outcome was pain intensity measured on the visual analog scale recorded at baseline and then at 72 hours and 1 week after treatment. RESULTS: At 1-week follow-up, pain intensity was significantly less in the DN group than in the waitlist control group (-2.16 [-1.01 to -3.32], P = .007) by an amount consistent with clinically meaningful improvement. DISCUSSION: The findings suggest that DN resulted in clinically meaningful short-term improvement in pain intensity of patients with PMS.

Ultrasound appears to be a reliable technique for the diagnosis of piriformis syndrome.

INTRODUCTION: Piriformis muscle syndrome (PS) is a disorder encompassing a constellation of symptoms, including buttock and hip pain. In this study we aimed to assess the value of ultrasound (US) in the diagnosis of PS. METHODS: Thirty-three clinically diagnosed PS patients and 26 healthy volunteers underwent a clinical PS scoring examination and US and MRI assessment of the bilateral piriformis muscles. The areas under the receiver operating characteristic curves (AUROCs) of the US parameters (i.e., increased thickness [iTh] and increased cross-sectional area [iCSA]) for piriformis muscle were evaluated. RESULTS: On US and MRI, the thickness and CSA were increased in PS patients. The AUROCs for the iTh and iCSA for discriminating stage 0 (healthy volunteers) from stage 1 through stage 3 (PS patients) were 0.88 and 0.95, respectively. DISCUSSION: US may be a reliable technique for the clinical diagnosis of PS. Muscle Nerve 59:411-416, 2019.

Is it painful to be different? Sciatic nerve anatomical variants on MRI and their relationship to piriformis syndrome.

OBJECTIVES: To investigate the purported relationship between sciatic nerve variant anatomy and piriformis syndrome. METHODS: Over 49 months, 1039 consecutive noncontrast adult hip MRIs were completed for various clinical indications. Repeat and technically insufficient studies were excluded. Radiologists categorized sciatic nerve anatomy into Beaton and Anson anatomical types. Chart review using our institution's cohort search and navigation tool determined the prevalence of the explicit clinical diagnosis of piriformis syndrome (primary endpoint) and sciatica and buttock pain (secondary endpoints). A Z-test compared the prevalence of each diagnosis in the variant anatomy and normal groups. RESULTS: Seven hundred eighty-three studies were included, with sciatic nerve variants present in 150 hips (19.2%). None of the diagnoses had a statistically significant difference in prevalence between the variant and normal hip groups. Specifically, piriformis syndrome was present in 11.3% of variant hips compared with 9.0% of normal hips (p = 0.39). CONCLUSIONS: There were no significant differences in the prevalence of piriformis syndrome, buttock pain, or sciatica between normal and variant sciatic nerve anatomy. This large-scale correlative radiologic study into the relationship between sciatic nerve variants and piriformis syndrome calls into question this purported relationship. KEY POINTS: • Large retrospective study relating variant sciatic nerve anatomy, present in 19.2% of hip MRIs, and piriformis syndrome • While sciatic nerve variant anatomy has previously been implicated in piriformis syndrome in small studies, no relationship was identified between sciatic nerve variants and piriformis syndrome.

Piriformis muscle syndrome: A cross-sectional imaging study in 116 patients and evaluation of therapeutic outcome.

OBJECTIVES: To increase the clinical awareness of piriformis muscle syndrome (PMs) by reporting cross-sectional imaging findings, the clinical impact of imaging studies and treatment outcome. METHODS: Within a 10-year-period, 116 patients referred for radiological evaluation of clinically suspected PMs, with excluded lumbar pathology related to symptomatology, were prospectively studied with MRI and/or computed tomography (CT). Piriformis muscle (PM), sciatic nerve (SN), piriformis region and sacroiliac joints were evaluated. PMs was categorised into primary/secondary, according to a reported classification system. Treatment decisions were recorded. Outcome was categorised using a 3-point-scale. RESULTS: Seventy-four patients (63.8%) exhibited pathologies related to PMs. Primary causes were detected in 12 and secondary in 62 patients. PM enlargement was found in 45.9% of patients, abnormal PM signal intensity/density in 40.5% and sciatic neuritis in 25.7%. Space-occupying lesions represented the most common related pathology. Treatment proved effective in 5/8 patients with primary and 34/51 patients with secondary PMs. In 34 patients, imaging revealed an unknown underlying medical condition and altered treatment planning. CONCLUSIONS: Secondary PMs aetiologies appear to prevail. In suspected PMs, PM enlargement represented the most common imaging finding and space-occupying lesions the leading cause. Imaging had the potential to alter treatment decisions. KEY POINTS: • In clinically suspected PMs cross-sectional imaging may reveal variable pathology. • Secondary PMs aetiologies appeared to be more common than primary. • PM enlargement represented the most common imaging finding in clinically suspected PMs. • Space-occupying lesions in the piriformis region represented the leading cause of PMs. • In clinically suspected PMs cross-sectional imaging may alter treatment planning.

Piriformis muscle syndrome with assessment of sciatic nerve using diffusion tensor imaging and tractography: a case report.

Piriformis muscle syndrome (PMS) is difficult to diagnose by objective evaluation of sciatic nerve injury. Here we report a case of PMS diagnosed by diffusion tensor imaging (DTI) and tractography of the sciatic nerve, which can assess and visualize the extent of nerve injury. The patient was a 53-year-old man with a 2-year history of continuous pain and numbness in the left leg. His symptoms worsened when sitting. Physical examination, including sensorimotor neurologic tests, the deep tendon reflex test, and the straight leg raise test, revealed no specific findings. The hip flexion adduction and internal rotation test and resisted contraction maneuvers for the piriformis muscle were positive. There were no abnormal findings on magnetic resonance imaging (MRI) of the lumbar spine. The transverse diameter of piriformis muscle was slightly thicker in affected side on MRI of the pelvis. A single DTI sequence was performed during MRI of the pelvis. Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the sciatic nerve were quantified at three levels using the fiber-tracking method. FA values were significantly lower and ADC values were significantly higher distal to the piriformis muscle. We performed endoscopic-assisted resection of the piriformis tendon. Intraoperatively, the motor-evoked potentials in the left gastrocnemius were improved by resection of the piriformis tendon. The patient's symptoms improved immediately after surgery. There was no significant difference in FA or ADC at any level between the affected side and the unaffected side 3 months postoperatively. MRI-DTI may aid the diagnosis of PMS.

Diffusion tensor imaging and tractography of the sciatic nerve: assessment of fractional anisotropy and apparent diffusion coefficient values relative to the piriformis muscle, a preliminary study.

OBJECTIVE: Piriformis muscle syndrome (PMS) is underdiagnosed. To evaluate the potential of diffusion tensor imaging and diffusion tensor tractography as innovative tools for the diagnosis of PMS by functional assessment of the sciatic nerve, the aims of this study are to assess the reproducibility and to evaluate the changes in the parameters at levels proximal and distal to the piriformis. MATERIALS AND METHODS: Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the sciatic nerve at three levels were quantified twice each by two examiners using the fiber-tracking method. In the first part of the study, laterality and reproducibility were evaluated using intraclass correlation coefficients (ICC) in ten healthy volunteers. In the second part of the study, the healthy side and symptomatic side were assessed in ten consecutive patients with sciatica. There were three patients with no findings on lumbar magnetic resonance imaging (MRI). RESULTS: There was no laterality in either FA or ADC values in asymptomatic patients at any level. The mean intra-rater ICC was 0.90 and the mean inter-rater ICC was 0.87. FA was significantly lower and ADC significantly higher on the symptomatic side at each level in patients with sciatica. In the three sciatica patients with no findings on lumbar MRI, FA was significantly lower and ADC was significantly higher only at levels distal to the piriformis. These patients experienced full pain relief after ultrasound-guided injection of local anesthesia. CONCLUSIONS: Diffusion tensor imaging and diffusion tensor tractography might be innovative tools for the diagnosis of PMS.

Could dry needling change the kinematics of gait in individuals with piriformis muscle syndromes? Secondary analysis of a randomized controlled trial.

INTRODUCTION: Piriformis muscle syndrome (PMS) is a condition that can lead to symptoms including gluteal pain, local tenderness, and limitation of hip joint motion in daily activities, and it may have a major impact on some daily functions such as gait. We proposed that dry needling (DN) can improve the gait of individuals with PMS. METHODS: Thirty-two individuals with PMS were assigned equally and randomly to the treatment group or the wait-list control group. Subjects in the treatment group received three sessions of DN of the piriformis muscle. All participants in both groups were educated to correct their lifestyles. The outcome measures were the gait-related parameters (walking speed, peak hip flexion, peak hip extension, time to peak internal and external hip rotation, and knee sagittal range of motion), which were evaluated at baseline and after treatment. To compare different outcomes, analysis of covariance (ANCOVA) was used, with baseline as the covariance and groups as a factor. RESULT: After DN sessions, peak hip extension during gait showed a statistically significant difference [adjusted MD 1.9 (3.7-0.08), p < 0.05, d = 0.56 (0.1-1.28)] in favor of the DN group. Peak hip flexion, on the other hand, exhibited a marginal statistically significant difference [adjusted MD -3.2 (-6.51 to 0.01), p = 0.053, d = 0.44 (1.16 to -0.02)] compared to the control group. CONCLUSION: The findings suggest that participants in DN showed significantly greater peak extension angle of the hip during walking in individuals with PMS than in the control group.

Piriformis syndrome as an overlooked cause of pain in a patient with axial spondyloarthritis: a case report.

Piriformis syndrome is a neuromuscular disorder characterized by hip, buttock, and leg pain. Axial spondyloarthritis is a rheumatic disease primarily affecting the sacroiliac joint and the spine. Due to their anatomical proximity, the potential relationship between piriformis syndrome and sacroiliitis has been discussed for some time. However, literature review revealed that there is no study on piriformis syndrome in individuals with axial spondyloarthritis. Here, we present the case of a 30-year-old female with axial spondyloarthritis who developed severe low back, hip, and buttock pain that persisted despite initial treatment for axial spondyloarthritis. We first re-evaluated her condition through physical examination, magnetic resonance imaging, and an injection test for piriformis syndrome. Following a comprehensive assessment, the patient was diagnosed with both axial spondyloarthritis and piriformis syndrome. Subsequently, a tailored treatment plan was devised, addressing both conditions, and after a 3-month course of treatment, we obtained significant reduction in pain of the patient. This is the first case report in literature, where we used injection test to confirm the diagnosis of the piriformis syndrome in a patient with axial spondyloarthritis. We therefore strongly advocate considering piriformis syndrome as a potential etiology for pain in individuals with axial spondyloarthritis consistently. This recognition is important as piriformis syndrome does not respond adequately to non-steroidal anti-inflammatory drugs and may lead to unnecessary use of biological disease-modifying antirheumatic drugs. Timely identification and intervention are imperative in ensuring optimal patient care.

YouTube as a source of information on piriformis syndrome exercises.

Objectives: This study aimed to evaluate the quality and reliability of the most viewed YouTube videos on piriformis syndrome (PS) exercises and identify criteria that may be important for selecting high-quality and reliable videos. Materials and methods: We searched for the keywords "piriformis syndrome exercise," "piriformis syndrome rehabilitation," "piriformis syndrome physical therapy," and "piriformis syndrome physiotherapy" on November 28, 2021. The modified DISCERN (mDISCERN), and the Global Quality Score were used to evaluate the quality and reliability of the videos. Results: Of the 92 videos evaluated, most (58.7%) of the videos were shared by healthcare professionals. The median mDISCERN score was 3, and most of the videos were found to be medium or low quality. Videos with more subscribers (p=0.001), a shorter upload duration (p=0.001), videos uploaded by physicians (p=0.004), and videos uploaded by other healthcare professionals (p=0.001) were found to have high reliability. Conversely, videos uploaded by independent users were found to have low reliability (p<0.001). When the parameters of the videos were compared among the quality groups, significant differences were found in all video features (p<0.05), some upload sources (other healthcare professionals and independent users; p=0.001), and mDISCERN scores (p<0.001). Conclusion: It is beneficial for physicians and other health professionals to upload more videos about health to increase the amount of reliable and high-quality information.

Evaluation of the Efficacy of Ultrasound-Guided Dry Needling Therapy and Exercise in Piriformis Muscle Syndrome.

BACKGROUND:  Piriformis muscle syndrome (PMS) is characterized by symptoms of buttock pain and numbness radiating to the back of the thigh due to irritation of the sciatic nerve. This study aimed to evaluate the efficacy of dry needling (DN) therapy and exercise programs on pain, neuropathic pain, physical function, and disability in patients with PMS. METHODS:  Forty-four patients with PMS were included in the study. Patients were divided into two groups, those who were treated with DN three times once per week under ultrasound guidance and those who had an exercise program for three weeks. To identify the outcomes of the treatment modalities, pre-treatment and post-treatment first-month and third-month visual analog scale (VAS), Oswestry Disability Index (ODI) questionnaire, Lower Extremity Functional Scale (LEFS), and Douleur Neuropathique 4 (DN4) questionnaire scores were used. RESULTS:  There was no statistically significant difference between the groups in baseline scores of VAS (p = 0.548), DN4 (p = 0.446), and LEFS (p = 0.880), but in the DN group, baseline ODI scores were significantly higher than in the exercise group (p = 0.001). The group comparisons showed no statistically significant differences in decreasing pain, reducing disability, and increasing functional status scores among the groups at post-treatment first-month and third-month assessments (p > 0.05). CONCLUSION: Both treatment modalities are beneficial in reducing pain and disability, and increasing the functional status of the patients with PMS in three months of follow-up. In patients who cannot adapt to exercise programs, DN treatment under ultrasound guidance should be kept in mind as a minimally invasive treatment modality with no adverse effects.

Diagnostic Approach to Lower Limb Entrapment Neuropathies: A Narrative Literature Review.

Entrapment neuropathies of the lower limb are a misunderstood and underdiagnosed group of disorders, characterized by pain and dysesthesia, muscular weakness, and specific provoking movements on physical examination. The most frequent of these syndromes encountered in clinical practice are fibular nerve entrapment, proximal tibial neuropathy, sural nerve neuropathy, deep gluteal syndrome or sciatic nerve entrapment, and lateral femoral cutaneous nerve entrapment, also known as meralgia paresthetica. These are commonly mistaken for lumbar plexopathies, radiculopathies, and musculotendinous diseases, which appear even more frequently and have overlapping clinical presentations. A comprehensive anamnesis, physical examination, and electrodiagnostic studies should help clarify the diagnosis. If the diagnosis is still unclear or a secondary cause of entrapment is suspected, magnetic resonance neurography, MRI, or ultrasonography should be conducted to clarify the etiology, rule out other diseases, and confirm the diagnosis. The aim of this narrative review was to help clinicians gain familiarity with this disease, with an increase in diagnostic confidence, leading to early diagnosis of nerve damage and prevention of muscle atrophy. We reviewed the epidemiology, anatomy, pathophysiology, etiology, clinical presentation, and EDX technique and interpretation of the entrapment neuropathies of the lower limb, using articles published from 1970 to 2022 included in the Pubmed, MEDLINE, Cochrane Library, Google Scholar, EMBASE, Web of Science, and Scopus databases.

A case of severe sciatica caused by a lymphocele after renal transplantation.

BACKGROUND: Sciatica is commonly caused by lumbar spinal disease. However, it can also be caused by tumors, infectious diseases, or muscle entrapment. We present a case of sciatica caused by a lymphocele after renal transplantation. PRESENTATION: A 50-year-old man who had undergone renal transplantation presented with sciatica and low back pain without leg edema. The patient was diagnosed with lumbar disc herniation during the first medical examination. Regardless of the treatment, the symptoms were exacerbated and red flag signs of low back pain were observed. Compression of the sciatic nerve by the lymphocele was confirmed by computed tomography. The sciatica was improved by ethanol injection for the lymphocele. CONCLUSIONS: We encountered a rare case of severe sciatica without edema caused by lymphocele after renal transplantation. Careful examination is required to make a different diagnosis of lymphocele from other lumbar spinal diseases.

Piriformis Syndrome (Sciatic Nerve Entrapment) Associated With Type C Sciatic Nerve Variation: A Report of Two Cases and Literature Review.

Although anatomical variation of the sciatic nerve and piriformis muscle at the greater sciatic notch is considered an important cause of piriformis syndrome, there are few reports on the surgical treatment of piriformis syndrome owing to specific anatomical variations of the sciatic nerve and piriformis muscle. In this report, we describe 2 cases of piriformis syndrome caused by a rare type C sciatic nerve variation that were surgically treated using the transgluteal approach. The first patient reported unremitting left hip and leg pain that occurred following blunt trauma to the hip. The second patient complained of chronic pain in the buttocks and right leg, which persisted even after the patient underwent lumbar fusion surgery. Severe sitting pain and sciatica are symptomatic indications for the diagnosis of piriformis syndrome. A rare "C" type sciatic nerve variation was observed on the affected side under magnetic resonance imaging. Transgluteal sciatic nerve decompression provided significant pain relief. If severe sciatic nerve deformation due to a rare sciatic nerve variation can be confirmed with typical findings of piriformis syndrome, the possibility that sciatic nerve entrapment may have occurred in this variation should be considered.

Radiological Comparison of Femoral Neck-Shaft Angle in Piriformis Syndrome: A Case-Control Study.

Introduction: Variations in osseous, neural and muscular anatomical structures in the gluteal region have been investigated for their role in causing deep gluteal pain syndromes including piriformis syndrome. This study aimed to radiologically determine whether the femoral neck-shaft angle (NSA) in piriformis syndrome differs from that in a healthy population. Methods: Two groups of participants comprising 23 piriformis syndrome patients and 22 healthy controls were included in the present study. Piriformis syndrome was diagnosed based on clinical findings and the diagnosis was confirmed by intramuscular local anaesthetic injection. Femoral NSAs were measured from the anteroposterior pelvic radiographs and compared between the control and piriformis syndrome-affected groups. Results: The age, height, body weight, body mass index and gender distribution differences between the two groups (control and piriformis) were not statistically significant. The femur NSA was significantly lower in the piriformis group than in the control group. The receiver operating characteristic analysis revealed that the area under the curve, sensitivity and specificity for predicting the risk of piriformis syndrome (PS) were 0.946%, 100% and 86.36%, respectively, at an NSA cut-off of 127°. Conclusions: Reduced femoral NSA is related to PS. However, studies with a larger study sample are needed to further substantiate this finding. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-022-00736-y.

Efficacy of Ultrasound-Guided Injection of Botulinum Toxin, Ozone, and Lidocaine in Piriformis Syndrome.

Background: Piriformis syndrome (PS) is a painful musculoskeletal condition characterized by a deep gluteal pain that may radiate to the posterior thigh and leg. This study was designed to compare the effectiveness of ozone and BTX to lidocaine injection in treating piriformis syndrome that was resistant to medication and/or physical therapy. Study design: Between November 2018 and August 2019, we involved eighty-four subjects diagnosed with piriformis syndrome in a double-blinded, prospective, randomized comparative study to receive an ultrasound-guided injection of lidocaine (control group), botulinum toxin A, or local ozone (28 patients each group) in the belly of the piriformis muscle. Pain condition evaluated by the visual analog score (VAS) was used as a primary outcome, and the Oswestry Disability Index (ODI) as a secondary outcome, before, at one month, two months, three months, and six months following the injection. Results: The majority (58.3%) of patients were male, while (41.7%) were female. At one month, a highly significant decrease occurred in VAS and ODI in the lidocaine and ozone groups compared to the botulinum toxin group (p < 0.001). At six months, there was a highly significant decrease in VAS and ODI in the botulinum toxin group compared to the lidocaine and ozone groups (p < 0.001). Conclusion: Botulinum toxin may assist in the medium- and long-term management of piriformis syndrome, while lidocaine injection and ozone therapy may help short-term treatment in patients not responding to conservative treatment and physiotherapy.

Visualizing Anatomic Variants of the Sciatic Nerve Using Diagnostic Ultrasound During Piriformis Muscle Injection: An Example of 4 Cases.

Objective: The aim of this article is to present examples of patients in whom piriformis muscle (PM) and sciatic nerve (SN) variations were detected by a diagnostic ultrasound (US)-guided examination and were successfully diagnosed and treated for piriformis syndrome (PS) by US-guided injections. Clinical Features: This series includes 4 cases. In case 1, a 30-year-old woman with a 7 numeric rating scale (NRS) score for pain (on a 0-10 scale) was evaluated for complaints of left gluteal pain radiating to the thigh for 5 years and right gluteal pain for 2 years. Case 2 involves a 32-year-old man with a 7 NRS score presenting with left gluteal pain radiating to his leg for 1 year. The third case presents a 37-year-old man who had pain (6 NRS score), numbness, and discomfort radiating from the right hip to the leg that lasted for 7 years. Finally, in case 4, a 23-year-old male patient was examined with deep gluteal paresthesia and discomfort on the left side for 1 year. Intervention and Outcome: Diagnostic US evaluation of the gluteal region for each patient revealed anatomical variations of the SN. In 3 of the cases, corresponding contralateral US images demonstrated similar anatomic variations. Diagnosis of PS in each patient was made by US-guided injection. After the injection of 4 cm3 of lidocaine 2% into the PM, the patients' complaints resolved almost fully. Conclusion: The anatomical variations of the SN and PM might be a facilitating factor for myofascial pain syndrome in PS. These cases demonstrate that SN variations could be visualized with the help of diagnostic US.

Endoscopic Sciatic Neurolysis for Deep Gluteal Syndrome: A Systematic Review.

Deep gluteal syndrome (DGS) is an underdiagnosed condition caused by an extra-spinal entrapment of the sciatic nerve in the deep gluteal space. Symptomatic patients who fail conservative treatment require surgical decompression of the nerve either by an open or endoscopic approach. In recent times, there has been an increasing trend towards minimally invasive surgery performed with endoscopic techniques. This systematic review aimed to assess the effectiveness of endoscopic sciatic nerve decompression in the management of DGS. A comprehensive search of the PubMed, Web of Science, Cumulated Index to Nursing and Allied Health Literature (CINAHL), and SPORTDiscus databases were performed on January 3, 2022. All English-language clinical studies on DGS treated with endoscopic surgical decompression were included. The initial search criteria identified 145 articles, of which four studies were available for the final review. There was one level III evidence, while the remaining three were level IV, comprising 144 patients with a mean age of 46 years. The Coleman methodology score (CMS) was utilized to assess the quality of the studies and the mean score was 62 (range, 52 to 71). The presence of fibrovascular bands and bursal tissue was the most common cause of DGS, followed by musculotendinous structures. The average follow-up of the included studies was 26.3 months (range, 12 to 32 months). Less favorable outcomes were seen in patients with major traumatic sciatic neuropathies after fractures or open reconstructive hip surgeries. Conversion to formal open surgery was recorded in one case of DGS caused by sciatic nerve schwannoma due to poor endoscopic access. One patient developed postoperative recurrent sciatic nerve entrapment due to a foreign body reaction requiring an open decompression. Overall, the available studies reported a high degree of clinical success with a low rate of complications, albeit no high-quality studies could be identified.

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.