Long-term outcome of low-energy extracorporeal shockwave therapy on gluteal tendinopathy documented by magnetic resonance imaging

Abstract

Background: Previous outcome studies for extracorporeal shock wave therapy (ESWT) have included clinically diagnosed greater trochanteric pain syndrome (GTPS). The purpose of this study is to investigate outcome of ESWT on GTPS with gluteal tendinopathy documented by magnetic resonance imaging (MRI).

Methods: Medical records of 38 consecutive patients were retrospectively reviewed, who underwent ESWT for GTPS with MRI-documented gluteal tendinopathy (> 6 months). ESWT was conducted (1/week) when the Roles-Maudsley score (RMS) showed "Poor" or "Fair" grade after conservative treatment until RMS had reached "Good" or "Excellent" grade (treatment success) or until 12 treatments had been applied. Numeric rating scale (NRS) and RMS were evaluated before, 1 week after (immediate follow-up) and mean 27 months after ESWT program (long-term follow-up). Success rate was calculated at each follow-up point.

Results: Initial NRS (5.9 ± 1.6) significantly decreased at immediate (2.5 ± 1.5, p< 0.01) and long-term follow-up (3.3 ± 3.0, p< 0.01), respectively. Success rates were 83.3% (immediate) and 55.6% (long-term), respectively. There was no correlation among age, symptom duration and NRS.

Conclusion: Low-energy ESWT can be an effective treatment for pain relief in chronic GTPS with MRI-documented gluteal tendinopathy. However, its long-term effect appears to decrease with time.

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1. Findings of magnetic resonance imaging of gluteal tendinopathy.

A: Mild increased intrasubstance signal and surrounding edema (arrow) suggests gluteus medius tendinosis with peritendinitis. B: Marked increased intrasubstance signal and ill-definition of the gluteus medius tendon near the insertion on the lateral facet (arrow) suggests insertional partial tear. C: Contrast-enhanced axial T1 with fat saturation MR images demonstrates a hypointense calcium deposit (arrow) in the gluteus medius tendon with surrounding edema. D: Mild increased intrasubstance signal and surrounding edema (arrow) suggests gluteus minimus tendinosis with peritendinitis.

Fig 2. Flow chart for the inclusion of eligible subjects in this study.

Fig 3. Outcome of ESWT for subjective pain at immediate follow-up (1 week after ESWT program) and long-term follow-up (mean 27 months after ESWT program).