Comparing radial extracorporeal shockwave therapy and corticosteroid injection in the treatment of piriformis syndrome: A randomized clinical trial.

OBJECTIVE: This study was designed to compare the effects of shockwave therapy and corticosteroid injection in the treatment of piriformis syndrome.

METHODS AND MATERIALS: In this randomized clinical trial, thirty-five patients with piriformis syndrome were randomly divided into two groups of 18 in the shockwave group and 17 in the corticosteroid group. The Shockwave group underwent three sessions of shockwave therapy per week (2000 pulses per session with 5Hz frequency and pressure equal to 4 Bar) and the corticosteroid group underwent an injection of 40 mg methylprednisolone with 1 mL of 1% lidocaine under ultrasound guidance. All patients were assessed by SF-36 questionnaire and visual analogue scale (VAS). The SF-36 questionnaire was used to evaluate the quality of life before and 4 weeks after the intervention. VAS scale was used to evaluate pain before the intervention, and 1, 4, 8, and 12 weeks after the intervention.

RESULTS: The baseline characteristics of the two groups were not significantly different. At the end of the study, both groups had a significant improvement in pain and quality of life compared to before the intervention. However, according to the VAS, in the shockwave group improvement was seen in the first follow-up while not seen in the corticosteroid group (P-value <0.001 and P-value 1.00, respectively). According to the SF-36 questionnaire, the overall score in both groups had a significant improvement (P-value <0.05).

CONCLUSIONS: It seems that shockwave therapy and corticosteroid injection are both effective in the treatment of piriformis syndrome. There was no significant difference between the two groups in the quarterly follow-up. Because shockwave therapy is a relatively non-invasive treatment with fewer side effects, it can be useful to improve pain and the quality of life of patients with piriformis syndrome.