Effectiveness of different percutaneous electrolysis protocols in the endogenous modulation of pain: A Double-Blinded Randomized Clinical Trial.

OBJECTIVE: This randomized clinical trial investigated if the application of percutaneous electrolysis (PE) enhances endogenous pain mechanisms (EPM) when compared with a simple needle application (acting as sham). METHODS: Forty-six asymptomatic subjects, aged 18-40 years, were randomized into three groups receiving a single ultrasound-guided PE intervention consisting of a needle insertion on the lateral epicondyle: sham (without electrical current), low-intensity (0.3 mA, 90s), or high-intensity (three pulses of 3 mA, 3s) PE. Widespread pressure pain thresholds (PPT), conditioned pain modulation (CPM), and temporal summation (TS) were bilaterally assessed in the lateral epicondyle, bicipital groove, transverse process of C5 and tibialis anterior muscle. Outcomes were obtained by an assessor blinded to the treatment allocation of the subjects. RESULTS: No significant changes in CPM were observed in either group (omnibus ANOVA all, P > .05). A significant bilateral increase in PPT in the lateral epicondyle in the high intensity group as compared with the sham group was observed (P < .01). A significant decrease of TS in both low (P = .002) and high (P = .049) intensity groups on the right, but not on the left, tibialis anterior was also observed when compared with the sham group. CONCLUSIONS: One session of PE is able to slightly stimulate modulatory pathways related to nociceptive gain, particularly pressure pain sensitivity and temporal summation but not conditioning pain modulation, when compared with a sham needle intervention, with changes even contralaterally. No significant differences were found between low- and high-intensity doses of percutaneous electrolysis.

Cadaveric and Ultrasound Validation of Percutaneous Electrolysis Approach at the Distal Biceps Tendon: A Potential Treatment for Biceps Tendinopathy.

Distal biceps brachii tendinopathy is a musculoskeletal pain condition-comprising chronic intrasubstance degeneration with alterations of the tendon structure-that is difficult to treat. Preliminary evidence suggests a positive effect for pain and related disability of percutaneous electrolysis treatment in patients with tendinopathy. Ultrasound is an excellent diagnostic tool to identify tendon injuries, such as tendinopathy, and to guide treatment approaches. Different approaches using ultrasound evaluation of the biceps tendon have been described. Our aim was to determine the validity and safety of a percutaneous electrolysis approach, targeting insertion of the distal tendon of biceps brachii, in both human (ultrasound-guided) and Thiel-embalmed cadaver (not ultrasound-guided) models. There were two approaches evaluated: an anterior approach with the elbow in extension and the forearm in supination and a posterior approach with the elbow in flexion and the forearm in pronation. A needle was inserted following the tendon up to its insertion into the radial tuberosity. The anterior approach, both in cadaveric study and US-guided intervention, revealed a close relationship between the distal biceps tendon and the brachial artery. The mean distance of the depth of the biceps tendon distal to the brachial artery was 0.21 ± 0.021 cm in the cadavers and 0.51 ± 0.024 cm in subjects. It was also found that the anterior approach has a potential technical difficulty due to the anatomical location of the brachial artery. With the posterior approach, it was possible to safely identify the tendon insertion and the needle approach, since no important vascular and nervous structures were visualized in the window of insertion of the needle. The clinician rated the posterior approach as low difficulty in all subjects. Current results would support a posterior approach with US guidance as a safe approach for applying the percutaneous electrolysis technique for insertional tendinopathies of the distal biceps brachii tendon. The current study did not assess the effectiveness of the proposed intervention; accordingly, future studies investigating the clinical effectiveness of the proposed intervention are needed.