Effect of Ultrasound-guided Piriformis Muscle Corticosteroid Injection Versus Extracorporeal Shock Wave Therapy for Piriformis Syndrome: a Randomized Control Trial

Effect of Ultrasound-guided Piriformis Muscle Corticosteroid Injection Versus Extracorporeal Shock Wave Therapy for Piriformis Syndrome

In this study, the investigators aim to compare the effect of extracorporeal shockwave therapy with ultrasound-guided piriformis coticosteroid injection in treatment of PS.

Study Overview

• Status: Completed
• Conditions: Piriformis Syndrome; Therapeutic Exercise; Corticosteroid Injection; Extracorporeal Shockwave Therapy
• Intervention / Treatment: Procedure: Extracorporeal shockwave therapy (ESWT); Procedure: Ultrasound-guided piriformis steroid injection

Detailed Description

Piriformis syndrome (PS) is one of the common etiology of low back pain. The cause of PS is due to myofascial syndrome of piriformis muscle, leading to piriformis muscle spasm, string-like taut band, and trigger point. Consequently, it may compresses the sciatic nerve which arise from sciatic notch and passes under the piriformis muscle. Conservative treatment of PS includes therapeutic exercise, diathermy, and local steroid injection. Among them, as radiology techniques advance, ultrasound-guided piriformis injection becomes popular for diagnosis block and treatment. Nowadays, extracorporeal shockwave therapy has widely applied in musculoskeletal disease such as plantar fasciitis, tennis elbow, and calcific tendinitis of the shoulder. However, to the investigators best knowledge, there is no study comparing the therapeutic effect between local steroid injection and shockwave. In this study, the investigators aim to compare the effect of extracorporeal shockwave therapy with ultrasound-guided piriformis corticosteroid injection.

This is a randomized controlled trial. 70 participants will be randomly divided into shockwave group and injection group. The participant in the shockwave group will receive one time extracorporeal shockwave therapy, and injection group will receive one time ultrasound-guided piriformis muscle corticosteroid injection. After the intervention, participant in both groups will receive home-based stretch exercise. Evaluation will be performed at baseline, 1 week, and 5 weeks after intervention. Outcome measures include the pain visual analog scale (VAS), hip range of motion, change of pressure pain threshold, and Oswestry Disability Index (ODI).

• Study Type: Interventional
• Enrollment (Actual): 70
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Taiwan
  • Taipei, Taiwan
    • Shin Kong Wu Ho-Su Memorial Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age from 20 to 80
2. Unilateral buttock involvement without leg pain or paresthesia
3. Duration of symptoms ≥1 month
4. Positive trigger point or taut band at piriformis muscle, confirmed by palpation and ultrasound examination
5. Positive FAIR (flexion, adduction, internal rotation) test
6. Positive piriformis resistive test (patient actively abducts and/or externally rotates the hip while the examiner resists these movements

Exclusion Criteria:

1. Having received hip, pelvis, or lumbar spine surgery
2. Low back pain or buttock pain due to lumbosacral spine, hip or pelvis lesion other than piriformis syndrome
3. Having received shock wave therapy or corticosteroid injection for buttock pain within the past one month
4. Neurologic deficit in in the lower limbs
5. History of drug allergy to local anesthetics or corticosteroids
6. Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Shockwave group; each subject will receive extracorporeal shockwave therapy	Procedure: Extracorporeal shockwave therapy (ESWT); The therapy will be performed with the focused piezoelectric shockwave (F10G4 Richard Wolf GmbH, Germany). The patient will be kept in the hip flexion, adduction and internal rotation position. After sonography-guided localization of the affected muscle and identification of the trigger point by the participant, ultrasound gel is applied to the skin and the applicator couple is placed with an impulse energy flux density of 0.456-0.882 mJ/mm2 for 3500 impulses.
Active Comparator: Injection group; each subject will receive ultrasound-guided piriformis corticosteroid injection	Procedure: Ultrasound-guided piriformis steroid injection; all the participants will receive ultrasound-guided piriformis injection with 10 mg triamcinolone and 1 c.c. 1% lidocaine for one time.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The pain visual analog scale (VAS)	It measures severity of pain. It is performed with a 100-mm horizontal line. The end of the left side is defined as no pain, and the end of the right side as the worst pain. Participants are requested to report the severity of buttock pain in recent one week.	change between baseline and at 1 week, 5 weeks after the beginning of the treatment.
Oswestry Disability Index (ODI)	ODI score is used for disability evaluation. It is a self-reported questionnaire with range 0-100. It has 10 questions with an minimal clinical important difference (MCID) of 10 points, with higher scores indicating more disability. The questions include pain intensity, sleep quality, and ability to perform personal care, work, sit, walk, lift, stand, and travel.	change between baseline and at 1 week, 5 weeks after the beginning of the treatment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
hip range of motion	Internal and external rotation of the hip on the affected side will be measured with a goniometer by the study assistant. The measurement will be performed in the supine position according the standard procedure.	change between baseline and at 1 week, 5 weeks after the beginning of the treatment.
change of pressure pain threshold	It is defined as the amount of pressure needed to shift local sensation from pressure to pain. This is measured with a digital algometer and has been shown to have excellent intrarater reliability in the gluteal region (ICC = .90), with a minimal detectable change of 3.1 N/cm2. The digital algometer, made up of a 1-cm-wide disk, will be placed at the tender point between the ischial tuberosity and the greater trochanter while the patient is lying prone. The algometer's pressure will be increased gradually (with a speed approximately 1 N/cm2 per second) until the participant reports pain. The average value of three repeated measurements is recorded.	change between baseline and at 1 week, 5 weeks after the beginning of the treatment.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient's self evaluation	At 1-week and 5-week evaluations, patients are asked to report treatment effect by themselves as the following five grades: 5. Complete relief of symptoms; 4. Much improved, no need for further treatment; 3. Mildly improved, need further treatment; 2.No improvement; 1. Worse.	change between baseline and at 1 week, 5 weeks after the beginning of the treatment.

Collaborators and Investigators

• Sponsor: Shin Kong Wu Ho-Su Memorial Hospital
• Investigators: Principal Investigator: Lin-Fen Hsieh, Shin Kong Wu Ho-Su Memorial Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2021
• Primary Completion (Actual): December 31, 2022
• Study Completion (Actual): December 31, 2022

Study Registration Dates

• First Submitted: December 21, 2020
• First Submitted That Met QC Criteria: December 21, 2020
• First Posted (Actual): December 24, 2020

Study Record Updates

• Last Update Posted (Actual): July 12, 2023
• Last Update Submitted That Met QC Criteria: July 10, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: corticosteroid injection; therapeutic exercise; Piriformis syndrome; ultrasound-guided intervention; extracorporeal shockwave therapy
• Additional Relevant MeSH Terms: Pathologic Processes; Nervous System Diseases; Pain; Neurologic Manifestations; Disease; Neuromuscular Diseases; Sciatic Neuropathy; Mononeuropathies; Peripheral Nervous System Diseases; Neuralgia; Nerve Compression Syndromes; Pelvic Pain; Syndrome; Piriformis Muscle Syndrome
• Other Study ID Numbers: 20200715R; 2021SKHADR033 (Other Grant/Funding Number: Shin Kong Wu Ho-Su Memorial Hospital)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No