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

Abstract

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.

Keywords: brachial artery; cadaver; distal biceps brachii tendon; percutaneous electrolysis; tendinopathy.

Figure 1

(A) Anatomical schematic of the relationship between the brachial artery and vein (blue and red pins), the median nerve (yellow pin), and the distal biceps tendon (green pin). (B) Detailed view (orientation arrow indicates: cranial).

Figure 2

Anatomical schematic of the needle insertion with the elbow in flexion and the forearm in pronation “Cobra position”: (A) general view; (B) detailed view (tendon insertion-green pin). (C) US imaging of the short axis view (pronated position). The tendon insertion (hyperechoic) is observed on the radius tuberosity; (DBt)-Distal Biceps Tendon (Asterisk), (Uln)-Ulna, (Rad)-Radius). No important vascular or nervous structure was visualized (Color Power Doppler image).

Figure 3

(A) Illustration of the percutaneous electrolysis approach with the elbow extended and supinated; (B) US imaging (Color Power Doppler) of the relationship between the brachial artery and the distal biceps tendon in long axis, with the elbow extended and supinated. (C) US image (Color Power Doppler) in short axis with the forearm supinated of the relationship and measurement of the brachial artery and median nerve to the tendon in a healthy volunteer. (DBt)-Distal Biceps Tendon, (Bart)-Brachial artery, (n)-Median nerve), (Rad)-Radial Tuberosity).

Figure 4

(A) Illustration of the percutaneous electrolysis approach with the elbow flexed and pronated in “Cobra position”; (B) US imaging of the needle inserting into the distal biceps tendon in short axis, with the elbow flexed and pronated. (DBt)-Distal Biceps Tendon (Asterisk), (Uln)-Ulna, (Rad)-Radius).