No abstract available.
Piriformis Muscle Syndrome*

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

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

The piriformis syndrome is a condition allegedly attributable to compression of the sciatic nerve by the piriformis muscle. Recently, magnetic resonance neurography and electrophysiologic study have helped to diagnose piriformis syndrome. High dose radiotherapy could induce acute and delayed muscle damage. We had experienced piriformis syndrome with fatty atrophy of piriformis muscle after radiotherapy for recurrent cervical cancer.
Atrophy ; Magnetic Resonance Spectroscopy ; Muscles ; Piriformis Muscle Syndrome ; Sciatic Nerve ; Sciatic Neuropathy ; Uterine Cervical Neoplasms

BACKGROUND: The objective was to evaluate the distance from the skin and the diameter of the piriformis muscle and their relationship to the body mass index (BMI). METHODS: The study was a prospective study involving 60 patients. Patients were prepared on a radiological table in the prone position. Several images were obtained of each. In this view, the distance between the subcutaneous tissue and the piriformis muscle, and the diameter of the piriformis, were measured at three points (medially to laterally). RESULTS: The distance to the piriformis from the skin was 6.6 +/- 0.9 cm, 6.3 +/- 0.8 cm, and 5.2 +/- 0.9 cm in terms of the lateral, center, and medial measurement, respectively. The center of the piriformis had a greater diameter with 1.7 +/- 0.4 (0.9-2.5) cm. The distance to the piriformis increased with BMI. CONCLUSIONS: This study shows that the lateral of the piriformis muscle has a relatively greater distance from the skin. The center of the piriformis showed a greater diameter than other two portions. We found that the distance of the piriformis from subcutaneous tissues was correlated with BMI, but the diameter of the piriformis was not affected by BMI. These measurements can be used as a reference for determining the piriformis injection site in patients with piriformis syndrome.
Body Mass Index ; Humans ; Muscles ; Piriformis Muscle Syndrome ; Prone Position ; Prospective Studies ; Skin ; Subcutaneous Tissue

The piriformis syndome is a rare condition characterized by pain and paresthesia in the buttock, often radiating to the posterior thigh. Symptoms are made worse by hip adduction and internal rotation of the hip joint. We report two cases of piriformis syndrome caused by an atypical sciatic nerve pathway combined with hamstring hypertrophy.
Buttocks ; Hip ; Hip Joint ; Hypertrophy ; Paresthesia ; Piriformis Muscle Syndrome* ; Sciatic Nerve ; Thigh

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

Secondary piriformis syndrome may develop under several conditions. We report on the method and usefulness of arthroscopic treatment of the piriformis muscle and benign perineural cyst of the sciatic nerve. Arthroscopic assessment was performed to a perineural cyst on the sciatic nerve seen through EMG and hip MRI. Through the posterior and posteroinferior portal, the lesion below the piriformis muscle was confirmed following release of the tendon. The incision and drainage of the perineural cyst was done so as to achieve decompression. The excision of the lesion was not carried out so as to avoid injury to the sciatic nerve. Symptoms did not recur during 10 months of follow up appointments.
Appointments and Schedules ; Decompression ; Drainage ; Follow-Up Studies ; Hip ; Muscles ; Piriformis Muscle Syndrome ; Sciatic Nerve ; Tarlov Cysts

OBJECTIVE: To identify the optimal site for piriformis muscle injection, using easily detectable sacroiliac joint as a landmark, under fluoroscopic guidance. METHOD: We examined the anatomic relationships of the sciatic nerve, piriformis muscle and sacroiliac joint in 18 buttocks from 9 cadavers. The distance from the inferior margin of the sacroiliac joint to the piriformis muscle at the crossing point with the sciatic nerve, and the width of the sciatic nerve at that point were measured. We assessed the depth of the piriformis muscle and the sciatic nerve using ultrasonography in asymptomatic controls. RESULTS: The mean distance from the inferior margin of the sacroiliac joint to the piriformis muscle at the crossing point with the sciatic nerve was 15.7+/-3.4 (12~22) mm laterally and 16.5+/-4.1 (10~25) mm caudally. The mean width of the sciatic nerve at that point was 15.4+/-3.7 (12~22) mm. Ultrasonographic findings revealed the mean distance as 4.48+/-0.49 cm from the skin to the surface of the piriformis muscle and as 5.68+/-0.62 from the skin to the surface of the sciatic nerve. CONCLUSION: The most optimal injection site for piriformis syndrome was located 15.6+/-3.4 (12~22) mm laterally and 16.5+/-4.1 (10~25) mm caudally from the inferior margin of the sacroiliac joint.
Buttocks ; Cadaver ; Muscles ; Piriformis Muscle Syndrome ; Sacroiliac Joint ; Sciatic Nerve ; Skin

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