Effective Stretching Positions of the Piriformis Muscle Evaluated Using Shear Wave Elastography.

CONTEXT: Piriformis syndrome is often associated with muscle spasms and shortening of the piriformis muscle (PM). Physical therapy, including static stretching of the PM, is one of the treatments for this syndrome. However, the effective stretching position of the PM is unclear in vivo. This study aimed to determine the effective stretching positions of the PM using ultrasonic shear wave elastography. DESIGN: Observational study. METHODS: Twenty-one healthy young men (22.7 [2.4] y) participated in this study. The shear elastic modulus of the PM was measured at 12 stretching positions using shear wave elastography. Three of the 12 positions were tested with maximum internal rotation at 0°, 20°, or 40° hip adduction in 90° hip flexion. Nine of the 12 positions were tested with maximum external rotation at positions combined with 3 hip-flexion angles (70°, 90°, and 110°) and 3 hip-adduction angles (0°, 20°, and 40°). RESULTS: The shear elastic modulus of the PM was significantly higher in the order of 40°, 20°, and 0° of adduction and higher in external rotation than in internal rotation. The shear elastic modulus of the PM was significantly greater in combined 110° hip flexion and 40° adduction with maximum external rotation than in all other positions. CONCLUSION: This study revealed that the position in which the PM was most stretched was maximum external rotation with 110° hip flexion and 40° hip adduction.

Effects of ELDOA and post-facilitation stretching technique on pain and functional performance in patients with piriformis syndrome: A randomized controlled trial.

BACKGROUND: Piriformis syndrome (PS) is a neuro-muscular condition, which is often underdiagnosed in clinical settings. This study will determine the effects of myofascial stretching Elongation Longitudinaux Avec Decoaption Osteo Articulaire (ELDOA) and post-facilitation stretching of the piriformis muscle in patients with PS. OBJECTIVE: We aimed to compare the effects of ELDOA and post-facilitation stretching of the piriformis muscle on pain, muscle length and functional performance in patients with PS. METHODS: A randomized clinical trial was conducted with 40 PS patients including both males and females, between the ages of 30-70. Patients were randomly assigned to the ELDOA or post-facilitation group after assessments with the Numeric Pain Rating Scale (NPRS), Lower Extremity Functional Scale (LEFS), Piriformis Length Test and Straight Leg Raise (SLR). The assessments were done at baseline and at the end of the sixth week of treatment. RESULTS: The patients treated with ELDOA demonstrated significant improvement in pain (pre = 7.00 ± 2.75, post = 3.00 ± 1.75), piriformis length (pre = 27.6 ± 5.54, post = 36.8 ± 3.13), SLR (pre = 36.40 ± 7.24, post = 67.5 ± 8.36) and LEFS (pre = 26.90 ± 12.24, post = 58.10 ± 8.62), as compared with the group treated with post-facilitation stretching: pain: pre = 6.00 ± 1.00, post = 2.00 ± 1.50; piriformis length: pre = 28.55 ± 4.03, post = 38.8 ± 2.70; SLR: pre = 40.60 ± 7.48, post = 74.25 ± 5.19, and LEFS: pre = 25.20 ± 7.66, post = 66.30 ± 7.27). CONCLUSION: It can be concluded that the post-facilitation stretching technique shows more improvement in pain, muscle length, SLR, and LEFS in patients with PS as compared to ELDOA.

Deep gluteal syndrome as a cause of posterior hip pain and sciatica-like pain.

Deep gluteal syndrome is an increasingly recognized disease entity, caused by compression of the sciatic or pudendal nerve due to non-discogenic pelvic lesions. It includes the piriformis syndrome, the gemelli-obturator internus syndrome, the ischiofemoral impingement syndrome, and the proximal hamstring syndrome. The concept of the deep gluteal syndrome extends our understanding of posterior hip pain due to nerve entrapment beyond the traditional model of the piriformis syndrome. Nevertheless, there has been terminological confusion and the deep gluteal syndrome has often been undiagnosed or mistaken for other conditions. Careful history-taking, a physical examination including provocation tests, an electrodiagnostic study, and imaging are necessary for an accurate diagnosis. After excluding spinal lesions, MRI scans of the pelvis are helpful in diagnosing deep gluteal syndrome and identifying pathological conditions entrapping the nerves. It can be conservatively treated with multidisciplinary treatment including rest, the avoidance of provoking activities, medication, injections, and physiotherapy. Endoscopic or open surgical decompression is recommended in patients with persistent or recurrent symptoms after conservative treatment or in those who may have masses compressing the sciatic nerve. Many physicians remain unfamiliar with this syndrome and there is a lack of relevant literature. This comprehensive review aims to provide the latest information about the epidemiology, aetiology, pathology, clinical features, diagnosis, and treatment. Cite this article: Bone Joint J 2020;102-B(5):556-567.

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.

Effect of piriformis injection on neuropathic pain.

OBJECTIVES: The aim of this study was to investigate the effect of a piriformis injection on neuropathic pain in patients with piriformis syndrome. METHODS: Thirty patients with unilateral hip and/or leg pain, a positive FAIR test (increased H-reflex latency with Flexion, Adduction and Internal Rotation), and a trigger point at the piriformis muscle were enrolled in this prospective study. All of the patients exhibited neuropathic pain scored according to the Douleur Neuropathique 4 (DN4) of ≥4 for at least 6 months. All of the patients received 4 mL of lidocaine 2%+1 mL of betamethazone to the piriformis muscle under the guidance of ultrasound. The Numeric Rating Scale (NRS), DN4, and the painDETECT (PD) questionnaire were used for outcome assessment. RESULTS: A statistically significant improvement was seen in all scores (p<0.001) when both first week and first month results were compared with the baseline values. Comparison of the first week results with those of the first month revealed a statistically significant improvement in only the NRS and PD scores (p<0.001). The greatest improvement in all scores was seen in the first week after the injection. A mild increase was seen in all scores at the first month compared to the first week. CONCLUSION: A piriformis injection was found to be effective for both somatic and neuropathic pain in piriformis syndrome patients. Long-term follow-up is needed in order to consider this option alongside other treatment alternatives, like botulinum toxin and myofascial release.

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.

Targeted Ultrasound-Guided Perineural Hydrodissection of the Sciatic Nerve for the Treatment of Piriformis Syndrome.

Piriformis syndrome is a common cause of lumbar, gluteal, and thigh pain, frequently associated with sciatic nerve symptoms. Potential etiologies include muscle injury or chronic muscle stretching associated with gait disturbances. There is a common pathological end pathway involving hypertrophy, spasm, contracture, inflammation, and scarring of the piriformis muscle, leading to impingement of the sciatic nerve. Ultrasound-guided piriformis injections are frequently used in the treatment of these pain syndromes, with most of the published literature describing injection of the muscle. We describe a safe, effective ultrasound-guided injection technique for the treatment of piriformis syndrome using targeted sciatic perineural hydrodissection followed by therapeutic corticosteroid injection.

Evaluation of neural therapy effect in patients with piriformis syndrome.

BACKGROUND: The aim of this study was to explore the effect of neural therapy on pain and functionality in patients with low back pain due to piriformis syndrome. It also aimed to find out any possible links between the clinical changes and demographic features. METHOD: One hundred and two patients were randomly divided into two groups (neural therapy and control). All patients were given stretching exercises for the piriformis muscle. The patients in the neural therapy group additionally received 6 sessions of neural therapy. The visual analog scale (VAS) and Oswestry Disability Index (ODI) were noted before and after the treatment in both groups. RESULTS: The VAS and ODI improved in both groups. However, improvement of the VAS and ODI scores were more obvious in the neural therapy group. The changes of VAS and ODI values did not show any correlations with the demographic features. CONCLUSION: After the neural therapy, the patients with low back pain due to piriformis syndrome may have improvement in both pain and functioning.

Wallet Neuritis - An Example of Peripheral Sensitization.

BACKGROUND: Wallet neuritis is an example of extra-spinal tunnel neuropathy concerning sciatic nerve. Its clinical appearance often gets confused with sciatica of lumbar spine origin. Wallet- induced chronic sciatic nerve constriction produces gluteal and ipsilateral lower extremity pain, tingling, and burning sensation. It was Lutz, first describing credit-card wallet sciatica in an Attorney, surfaced on Journal of American Medical Association (JAMA), 1978; however, the condition has not been well-studied in various other occupations. CASE SUMMARY: In this write-up, we take the privilege of demonstrating wallet neuritis as an example of peripheral sensitization in three different professionals' namely specialist doctor, driver, and banker first time in Bangladesh. All the three patients' demonstrated aggravated gluteal pain with radiation on the homo-lateral lower extremity while remained seated on heavy wallet for a while, fortunately improved discontinuing such stuff with. Alongside radical wallectomy, piriformis stretching exercise on the affected side had also been recommended and found worthy in terms of pain relief. CONCLUSION: long-standing use of rear pocket wallet may compress and sensitize ipsilateral sciatic nerve, generating features resembling lumbago sciatica; thereby, remains a source of patients' misery and diagnostic illusion for pain physicians as well.

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.

Electrophysiologically identified piriformis syndrome is successfully treated with incobotulinum toxin a and physical therapy.

INTRODUCTION: Piriformis syndrome is entrapment of the sciatic nerve by the piriformis muscle. METHODS: In this article we describe a 56-person randomized, double-blind, controlled study involving physical therapy and incobotulinum toxin A or placebo. Inclusion criteria were 3-SD delay of posterior tibial (PT) or fibular (FN) H-reflexes on flexion, adduction, and internal rotation (FAIR) testing, and normal paraspinal electromyographic findings. Outcome measures included adverse side effects, visual analog scale (VAS) findings, and H-reflex delay on the FAIR test. RESULTS: Mean intervention VAS score decreased significantly more compared with placebo at 2, 4, 6, 8, 10, and 12 weeks post-injection (P < 0.0001). FAIR test scores for PT, but not FN, decreased significantly more compared with placebo at 2, 4, 6, and 8 weeks post-injection (PT: P = 0.038, 0.003, 0.003, and 0.046). Adverse effects were minimal. VAS slope and PT FAIR test results varied significantly (P < 0.0001). CONCLUSION: Incobotulinum toxin A chemodenervation may be useful for treating piriformis syndrome as identified by the FAIR test. Muscle Nerve 56: 258-263, 2017.

Bilateral piriformis syndrome in two elite soccer players: Report of two cases.

Piriformis syndrome, a relatively rare condition, is described as entrapment of a sciatic nerve at the level of the piriformis muscle. There have been a few reports of bilateral piriformis syndrome in literature. In this study, we present bilateral piriformis syndrome in two professional soccer players from different teams who are symptom free at last follow-up after surgery. In both patients, resting EMG records were read normal, however EMG recording during the activity revealed prolonged H-reflexes. Both patients had no relief from conservative treatment and rehabilitation, therefore surgical treatment was performed. Preoperative mean visual analogue scale (VAS) value was 7, and decreased to 3 at the sixth month follow-up visit and at the longer term follow-up, mean 85months (74-96) it was valued at 1. Both soccer players returned to their active sports lives in the sixth postoperative month. According to Benson's functional evaluation scale, in long-term follow-up, there have been excellent results and both patients resumed their professional carrier for many years (mean 7 years).

A new concept for evaluating muscle function in the lower extremities in cases of low back pain syndrome in anamnesis.

INTRODUCTION: There are difficulties in objective evaluation of activity of the muscles in the lower extremities of patients after successful treatment of sciatica and pseudosciatica, when no clear clinical symptoms are detected. However, the existence of some muscle dysfunction can be hypothesised and its detection was the aim of the study. OBJECTIVE: Recordings from chosen lower extremity muscles during standing were performed as supplementary differential diagnosis in evaluation of these patients. EMG in standing positions constitutes a new methodological approach not described in detail. METHODS: Twenty patients (11 after sciatica and 9 after sciatica-like episodes) were enrolled into the study. On the day of examination, clinical and electroneurographical (ENG; M and F waves tests) studies showed no pathology. The percentage of maximal voluntary contraction (MVC) defined muscle activity during standing. Mean amplitude and number of changes in muscle activity (fluctuations) were measured in surface electromyography recordings (sEMG) during normal standing and tandem positions. RESULTS AND CONCLUSIONS: Activity of proximal lower extremity muscles expressed as percentage of MVC was bilaterally increased in patients after sciatica in normal standing position, compared with results from the group of healthy volunteers (N=9). Patients after sciatica were also characterized with a significant increase of mean sEMG amplitude, recorded especially in distal muscles on the affected side during tandem position. This pathological change was related to decrease in 'fluctuations' frequency in patients after sciatica (P<0.001) more than after pseudosciatica (P<0.01) groups in both standing positions, compared to parameters of healthy volunteers. Sciatica and pseudosciatica in anamnesis cause different abnormal patterns of lower extremity muscle activity during standing positions when recorded with surface EMG.

Brief review: piriformis syndrome: etiology, diagnosis, and management.

PURPOSE: In this narrative review, we aim to provide the pathophysiology and diagnostic criteria of the piriformis syndrome (PS), an underdiagnosed cause of buttock and leg pain that can be difficult to treat. Based on existing evidence, frequencies of clinical features are estimated in patients reported to have PS. In view of the increasing popularity of ultrasound for intervention, the ultrasound-guided technique in the treatment of PS is described in detail. SOURCE: A literature search of the MEDLINE® database was performed from January 1980 to December 2012 using the search terms e.g., " piriformis injection", " ultrasound guided piriformis injection", " botulinum toxin", "pain management", and different structures relevant in this review. There was no restriction on language. PRINCIPAL FINDINGS: A review of the medical literature pertaining to PS revealed that the existence of this entity remains controversial. There is no definitive proof of its existence despite reported series with large numbers of patients. CONCLUSION: Piriformis syndrome continues to be a controversial diagnosis for sciatic pain. Electrophysiological testing and nerve blocks play important roles when the diagnosis is uncertain. Injection of local anesthetics, steroids, and botulinum toxin into the piriformis muscle can serve both diagnostic and therapeutic purposes. An ultrasound-guided injection technique offers improved accuracy in locating the piriformis muscle. Optimizing the therapeutic approach requires an interdisciplinary evaluation of treatment.

Treatment of an individual with piriformis syndrome focusing on hip muscle strengthening and movement reeducation: a case report.

STUDY DESIGN: Case report. OBJECTIVE: To describe an alternative treatment approach for piriformis syndrome using a hip muscle strengthening program with movement reeducation. BACKGROUND: Interventions for piriformis syndrome typically consist of stretching and/or soft tissue massage to the piriformis muscle. The premise underlying this approach is that a shortening or "spasm" of the piriformis is responsible for the compression placed upon the sciatic nerve. CASE DESCRIPTION: The patient was a 30-year-old male with right buttock and posterior thigh pain for 2 years. Clinical findings upon examination included reproduction of symptoms with palpation and stretching of the piriformis. Movement analysis during a single-limb step-down revealed excessive hip adduction and internal rotation, which reproduced his symptoms. Strength assessment revealed weakness of the right hip abductor and external rotator muscles. The patient's treatment was limited to hip-strengthening exercises and movement reeducation to correct the excessive hip adduction and internal rotation during functional tasks. OUTCOMES: Following the intervention, the patient reported 0/10 pain with all activities. The initial Lower Extremity Functional Scale questionnaire score of 65/80 improved to 80/80. Lower extremity kinematics for peak hip adduction and internal rotation improved from 15.9 degrees and 12.8 degrees to 5.8 degrees and 5.9 degrees, respectively, during a step-down task. DISCUSSION: This case highlights an alternative view of the pathomechanics of piriformis syndrome (overstretching as opposed to overshortening) and illustrates the need for functional movement analysis as part of the examination of these patients. LEVEL OF EVIDENCE: Therapy, level 4.

Piriformis syndrome: a real pain in the buttock?

OBJECTIVE: Herein, we provide an unbiased review of piriformis syndrome (PS), a highly controversial syndrome for which no consensus exists regarding diagnostic criteria or pathophysiology. METHODS: A review of the literature in the English language. RESULTS: A nonpartisan review of the medical literature pertaining to PS revealed that the existence of this entity remains controversial. There is no definitive proof of its existence despite reported series with large numbers of patients. CONCLUSION: PS remains a controversial diagnosis for sciatic pain. The debate regarding the clinical significance of PS remains active. Nonetheless, there may be a subset of patients in whom the piriformis muscle is a source of pain. The syndrome should be considered in the differential diagnosis of patients with unilateral lower extremity pain.