Clinical Question: Is extracorporeal shock wave therapy effective in treating tennis elbow?
Study Design: Randomized controlled trial (double-blinded)
Synopsis: Patients with tennis elbow were recruited from the general population and randomly assigned (concealed allocation) to extracorporeal shock wave therapy (n = 135) or sham therapy (n = 137). The main outcome of this study was success at 12 weeks. Success was defined as a return to full mobility and function with pain occurring occasionally or less often.
The researchers assessed the patients at six weeks, 12 weeks, and one year after treatment. With 272 patients, the study had an 80 percent likelihood of detecting a 20 percent difference in success rates if one really existed. At the end of one year, two thirds of patients in each group had improved. Extracorporeal shock wave therapy had no measurable effect on improvement at any of the interim evaluations or at the end of the study.
When the study concluded, about two thirds of the patients receiving extracorporeal shock wave therapy correctly guessed their treatment compared with about one half of those receiving sham therapy. I suspect that in this case this bias would work in favor of the active therapy. (Level of Evidence: 2b)
Bottom Line: This is one of several studies demonstrating that extracorporeal shock wave therapy is ineffective in treating tennis elbow and plantar fasciitis.