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.
Diagnosis ; Electromyography ; Femur ; Magnetic Resonance Imaging ; Needles ; Neural Conduction ; Piriformis Muscle 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.
Buttocks ; Diagnosis ; Follow-Up Studies ; Humans ; Male ; Piriformis Muscle Syndrome* ; Retrospective Studies ; Sciatic Nerve ; Sciatica ; Shock ; Uncertainty ; Visual Analog Scale

BACKGROUND: Motor weakness occurs frequently after piriformis injection and it could put patients at risk of falls. We investigated the appropriate concentration and volume of ropivacaine required to minimize motor dysfunction. METHODS: A total of 120 patients who received piriformis injection were included in this study. Piriformis injections of triamcinolone 10 mg in various concentrations (0.1%, 0.075%) and volumes (8, 10, 12 ml) of ropivacaine were administered in 20 patients, respectively. One hour after the injection, we compared motor function according to the concentrations and volumes of ropivacaine. RESULTS: There were significant differences (P < 0.05) in the occurrence of motor dysfunction according to body mass index (BMI) and the concentration of ropivacaine. No significant differences were found in terms of gender, age, weight, height, or the volume of ropivacaine. Logistic regression analysis showed that the likelihood of motor dysfunction with administration of 0.1% ropivacaine was 58.249 times greater than that with administration of 0.075% concentration (P < 0.001), while BMI did not have a significant effect on motor dysfunction. CONCLUSIONS: According to the results of this study, 0.075% ropivacaine rather than 0.1% ropivacaine is appropriate in terms of reducing motor dysfunction after piriformis injection.
Accidental Falls ; Body Mass Index ; Humans ; Logistic Models ; Piriformis Muscle Syndrome ; Triamcinolone

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.
Diagnosis ; Electromyography ; Female ; Humans ; Leg* ; Magnetic Resonance Imaging ; Muscle Weakness ; Piriformis Muscle Syndrome* ; Sciatic Nerve ; Sciatic Neuropathy ; Sciatica

As the expertise of the surgeon improves in arthroscopic surgery of the hip, the number of conditions treated by it also increases. In this case, an arthroscopic treatment was performed on a patient with piriformis syndrome due to schwannoma on the sciatic nerve. Meticulous excision of the cystic lesion on the sciatic nerve was completely performed and neither recurrence nor complication of the surgery was observed. Endoscopic excision using arthroscopy is useful for reducing postoperative pain and achieving early return to activities for the patient.
Arthroscopy* ; Hip* ; Humans ; Neurilemmoma* ; Pain, Postoperative ; Piriformis Muscle Syndrome ; Recurrence ; Sciatic Nerve*

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.
Electromyography ; Female ; Humans ; Injections, Epidural ; Male ; Medical Records ; Piriformis Muscle Syndrome* ; Steroids ; Ultrasonography

Acupuncture Therapy ; instrumentation ; Adult ; Female ; Humans ; Male ; Middle Aged ; Muscle Strength ; Piriformis Muscle Syndrome ; physiopathology ; therapy

OBJECTIVETo compare the efficacy differences between round-sharp needle of new nine-needle and elongated needle for piriformis syndrome, and explore its action mechanism.

METHODSEighty cases were randomly divided into a round-sharp needle of new nine-needle group (round-sharp needle group) and an elongated needle treatment group (elongated needle group), 40 cases in each group. The round-sharp needle group was treated with round-sharp needle (0.60 mm x 125 mm) at three points in piriformis with triple puncture method, while the elongated needle group was treated with elongated needle of ordinary specifications (0.32 mm x 125 mm) at three points in piriformis with triple puncture method. Besides, the two groups were also treated with routine acupuncture at Weizhong (BL 40) and Yanglingquan (GB 34), 3 times every week, 2 weeks as one course of treatment. After one course of treatment, the clinical effect was evaluated and the pain threshold values were measured before and after treatment in the two groups.

RESULTSThe total effective rate in the round-sharp needle group was 92.5% (37/40), which was superior to 77.5% (31/40) in the elongated needle group (P < 0.05). Compared before treatment, the pain threshold values after treatment in two groups were improved significantly (both P < 0.01). The increment of pain threshold value in the round-sharp needle group was higher than that in the elongated needle group (P < 0.01).

CONCLUSIONRound-sharp needle of new nine-needle is effective in treatment of piriformis syndrome and is better than ordinary elongated needle, which is related to that it can effectively increase pain threshold value of the local tissue.

Acupuncture Therapy ; instrumentation ; Adolescent ; Adult ; Female ; Humans ; Male ; Middle Aged ; Needles ; Piriformis Muscle Syndrome ; therapy ; Punctures ; methods ; Treatment Outcome ; Young Adult

Piriformis syndrome is a rare entrapment neuropathy in which the sciatic nerve is compromised by the piriformis muscle or other local structures. We report a case of sciatic and gluteal nerve lesions with infarction of the piriformis muscle following internal iliac artery embolization of the bilateral uterine vascular malformation. The surgical intervention revealed anatomical variation of the right sciatic nerve. To our knowledge, this is the first case of piriformis syndrome following endovascular treatment of uterine vascular malformation in Korea.
Arteriovenous Malformations ; Iliac Artery ; Infarction ; Korea ; Muscles ; Nerve Compression Syndromes ; Piriformis Muscle Syndrome ; Sciatic Nerve ; Vascular Malformations

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.
Adult ; Anesthetics, Local ; Buttocks ; Catheter Ablation ; Humans ; Low Back Pain ; Lower Extremity ; Male ; Paresthesia ; Physical Examination ; Piriformis Muscle Syndrome ; Sacroiliac Joint ; Sciatic Nerve ; Sensation