Shockwave therapy for the treatment of chronic proximal hamstring tendinopathy in professional athletes

Background: Chronic proximal hamstring tendinopathy is an overuse syndrome that is usually managed by nonoperative methods. Shockwave therapy has proved to be effective in many tendinopathies. Hypothesis: Shockwave therapy may be more effective than other nonoperative treatments for chronic proximal hamstring tendinopathy. Study Design: Randomized controlled clinical study; Level of evidence, 1. Methods: Forty professional athletes with chronic proximal hamstring tendinopathy were enrolled between February 1, 2004, and September 30, 2006. Patients were randomly assigned to receive either shockwave therapy, consisting of 2500 impulses per session at a 0.18 mJ/mm(2) energy flux density without anesthesia, for 4 weeks (SWT group, n = 20), or traditional conservative treatment consisting of nonsteroidal anti-inflammatory drugs, physiotherapy, and an exercise program for hamstring muscles (TCT group, n = 20). Patients were evaluated before treatment, and 1 week and 3, 6, and 12 months after the end of treatment. The visual analog scale (VAS) score for pain and Nirschl phase rating scale (NPRS) were used as primary outcome measures. Results: The patients were observed for a mean of 10.7 months (range, 1-12 months). Six patients were lost to follow-up because they underwent a surgical intervention: 3 (all in TCT group) were lost at 3 months; 2 (1 in each group), at 6 months; and 1 (in the TCT group), at 12 months. Primary follow-up was at 3 months after the beginning of treatment. The VAS scores in the SWT and TCT groups were 7 points before treatment (P = .84), and 2 points and 5 points, respectively, 3 months after treatment (P < .001). The NPRS scores in the SWT and TCT groups were 5 points in either group before treatment (P = .48), and 2 points and 6 points, respectively, 3 months after treatment (P < .001). At 3 months after treatment, 17 of the 20 patients (85%) in the SWT group and 2 of the 20 patients (10%) in the TCT group achieved a reduction of at least 50% in pain (P < .001). There were no serious complications in the SWT group. Conclusion: Shockwave therapy is a safe and effective treatment for patients with chronic proximal hamstring tendinopathy.