Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial

Abstract

Objective. To compare effects of ultrasound- (US-) guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n = 17) group or exercise (n = 19) group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions). Shoulder pain (NPRS) and disability (DASH) were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P < 0.01): individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention.

Figure 1

Long-axis grey-scale ultrasound image displaying the supraspinatus tendon during needle placement showing the echogenic needle during the application of US-guided percutaneous electrolysis.

Figure 2

Eccentric exercise of the supraspinatus muscle. Patients were asked to do a normal abduction (concentric phase) and a slow return to the initial position (eccentric phase).

Figure 3

Eccentric exercise of the infraspinatus muscle. Patients were asked to do a normal external rotation (concentric phase) and a slow return to the initial position (eccentric phase).

Figure 4

Stabilization exercise of the scapular musculature in kneeling position.

Figure 5

Needle approach during the application of US-guided percutaneous electrolysis. The figure shows the location of cathode (targeting the supraspinatus tendon) and anode (over the upper trapezius muscle) electrodes for application of percutaneous electrolysis. The transducer is placed on the supraspinatus tendon and the needle is inserted in the centre of the transducer in a long-axis position at an angle of about 30–45° to the skin surface, depending on the target area, and then advanced parallel to the sound beam.

Figure 6

Application of US-guided percutaneous electrolysis on a real patient with the clinician following the application on the ultrasound screen (a) and a detail of the application (b).

Figure 7

Flow diagram of patients throughout the course of the study.