Efficacy of ultrasound-guided piriformis muscle corticosteroid injection versus extracorporeal shockwave therapy in patients with piriformis syndrome: A randomized controlled trial

BACKGROUND: Piriformis syndrome (PS) is a condition that causes low back pain. Ultrasound-guided injection (USI) has become a popular option for diagnostic block and treatment. Extracorporeal shockwave therapy (ESWT) is widely used for treating musculoskeletal diseases. However, few studies have compared the therapeutic efficacy of local steroid injections and ESWT. OBJECTIVES: To compare the therapeutic efficacy of local corticosteroid injections and ESWT against PS. METHODS: This prospective randomized controlled trial enrolled 70 patients, who were randomly divided into two groups: the ESWT and USI groups. The ESWT group was subjected to one session of ESWT, and the USI group received one USI. Patients in both groups performed home-based stretching exercises. Evaluations were conducted at baseline and 1 and 5 weeks after the intervention. The outcomes included the patients' pain scores on a visual analog scale (VAS), Oswestry Disability Index (ODI), hip range of motion, side effects, and self-evaluation data. RESULTS: The groups did not vary significantly in terms of demographics. Significant time effects were observed in both groups, indicating post-treatment improvements. Furthermore, significant group effects were discovered in ODI and VAS pain scores. However, determining the superiority of one treatment over the other was challenging because of significant pretreatment differences between the groups in terms of ODI and VAS pain scores. However, no significant between-group difference was noted in the improvement rate. CONCLUSION: ESWT and USI appear to be effective in the treatment of PS. The levels of efficacy of the two treatment approaches may be similar. CLINICAL TRIAL REGISTRATION NUMBER: NCT04684537.