Effect of Ultrasound-guided Piriformis Muscle Corticosteroid Injection Versus Extracorporeal Shock Wave Therapy for Piriformis Syndrome: a Randomized Control Trial
Condition: Piriformis Syndrome; Corticosteroid Injection; Extracorporeal Shockwave Therapy; Therapeutic Exercise
MeSH terms: Piriformis Muscle Syndrome; Syndrome
Study type: Interventional

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

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).
    

Intervention name(s): Extracorporeal shockwave therapy (ESWT); Ultrasound-guided piriformis steroid injection
Intervention type(s): Procedure; Procedure
Intervention description(s): 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.; all the participants will receive ultrasound-guided piriformis injection with 10 mg triamcinolone and 1 c.c. 1% lidocaine for one time.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Piriformis syndrome; ultrasound-guided intervention; corticosteroid injection; extracorporeal shockwave therapy; therapeutic exercise