Three Sessions of Radial Extracorporeal Shockwave Therapy Gives No Additional Benefit Over "Minimal-Dose" Radial Extracorporeal Shockwave Therapy for Patients With Chronic Greater Trochanteric Pain Syndrome: A Double-Blinded, Randomized, Controlled Trial

Objective: To investigate the outcomes following 3 weekly sessions of radial extracorporeal shockwave therapy (rESWT) in patients with chronic greater trochanteric pain syndrome (GTPS) presenting to an NHS Sports Medicine Clinic in the United Kingdom. Design: Double-blinded randomized controlled trial. Setting: A single NHS Sports Medicine Clinic, in the United Kingdom. Patients: One hundred twenty patients in an NHS Sports Medicine clinic presenting with symptoms of GTPS who had failed to improve with a minimum of 3 months of rehabilitation were enrolled in the study and randomized equally to the intervention and treatment groups. Mean age was 60.6 +/- 11.5 years; 82% were female, and the mean duration of symptoms was 45.4 +/- 33.4 months (range, 6 months to 30 years). Interventions: Participants were randomized to receive either 3 sessions of ESWT at either the "recommended"/"maximally comfortably tolerated" dose or at "minimal dose." All patients received a structured home exercise program involving flexibility, strength, and balance exercises. Main Outcome Measures: Follow-up was at 6 weeks, 3 months, and 6 months. Outcome measures included local hip pain, validated hip PROMs (Oxford hip score, non-arthritic hip score, Victorian Institute of Sport assessment questionnaire), and wider measures of function including sleep (Pittsburgh sleep quality index) and mood (hospital anxiety and depression scale). Results: Results were available for 98% of patients at the 6-month period. There were statistically significant within-group improvements in pain, local function, and sleep seen in both groups. However, fewer benefits were seen in other outcome measures, including activity or mood. Conclusion: There were no time x group interaction effects seen between the groups at any time point, indicating that in the 3 sessions, the "recommended-dose" rESWT had no measurable benefit compared with "minimal dose" rESWT in this group of patients with GTPS. The underlying reason remains unclear; it may be that rESWT is ineffective in the treatment of patients with chronic GTPS, that "minimal dose" rESWT is sufficient for a therapeutic effect, or that a greater number of treatment sessions are required for maximal benefit. These issues need to be considered in further research.