Can transcutaneous electrical nerve stimulation improve achilles tendon healing in rats?

Abstract

| Background: Tendon injury is one of the most frequent injuries in sports activities. TENS is a physical agent used in the treatment of pain but its influence on the tendon's healing process is unclear. Objective: To evaluate the influence of TENS on the healing of partial rupture of the Achilles tendon in rats. Method: Sixty Wistar rats were submitted to a partial rupture of the Achilles tendon by direct trauma and randomized into six groups (TENS or Sham stimulation) and the time of evaluation (7, 14, and 21 days post-injury). Burst TENS was applied for 30 minutes, 6 days, 100 Hz frequency, 2 Hz burst frequency, 200 µs pulse duration, and 300 ms pulse train duration. Microscopic analyses were performed to quantify the blood vessels and mast cells, birefringence to quantify collagen fiber alignment, and immunohistochemistry to quantify types I and III collagen fibers. Results: A significant interaction was observed for collagen type I (p=0.020) where the TENS group presented lower percentage in 14 days after the lesion (p=0.33). The main group effect showed that the TENS group presented worse collagen fiber alignment (p=0.001) and lower percentage of collagen III (p=0.001) and the main time effect (p=0.001) showed decreased percentage of collagen III at 7 days (p=0.001) and 14 days (p=0.001) after lesion when compared to 21 days. Conclusions: Burst TENS inhibited collagen I and III production and impaired its alignment during healing of partial rupture of the Achilles tendon in rats.

High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture

“…There are other important results using different types of current for electrical stimulation, such as enhancement of intrinsic tenoblastic repair in vitro 29 and increase in capillaries and fibroblasts at the early stage of tissue repair 23 ; in terms of low voltage microamperage stimulation, an improved tensile strength of partially transected Achilles tendons at four weeks after injury 24 and burst transcutaneous electrical nerve stimulation (TENS) that inhibited collagen I and III production and impaired its alignment during healing of partial rupture of the Achilles tendon in rats 30 . More studies should be conducted with different parameters, e.g., analysis of collagen synthesis using real-time polymerase chain reaction (RT-PCR) or immunohistochemistry, identifying some key genes and proteins important for healing tendon such as vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), insulin-like growth factor (IGF), connective tissue growth factor (CTGF), matrix metalloproteinases (MMPs), tenascin C, and important proteoglycans.…”

Does electrode placement influence tens-induced antihyperalgesia in experimental inflammatory pain model?

“…We anesthetized the rats with isoflurane, initially with 5%, and maintained with 1–2% for 20 min of treatment of TENS. 16 It has been previously demonstrated that 1 application of isoflurane without TENS has no effect on paw withdrawal latency to heat induced by joint inflammation and 2 application of TENS to a non-inflamed knee joint has no effect on paw withdrawal latency. 17 EMPI Select TENS units with an asymmetrical biphasic square wave and circular electrodes were used.…”

“…1 These side effects were seen only in the burst TENS, which inhibited collagen I and III production and impaired its alignment during partial rupture of the Achilles tendon in rats. 2 …”

Dynamics of sensory and motor deficiency against the background of transcutaneous electroneuro stimulation in the therapy of patients with diabetic distal polyneuropathy

“…11,4 Direct stimulation of the nerve in the treatment of distal polyneuropathy has been used for the first time since 2010 and has been proven by the authors that the direct stimulation of the peroneal and tibial nerves is more effective in treating sensory and motor disorders than in indirect methods of stimulation (stimulation of muscle fibers of m. Tibialis anterior ete m. Triceps surae ). 1,5,12,13,14 The regression of motor and sensory fibers, depending on the frequency and amplitude of the applied current, has not been sufficiently studied. 1,5,10,15 In this regard, the purpose of our work was determined: to conduct a comparative analysis between a high-frequency lowamplitude TENS (HL TENS) and a low-frequency high-amplitude TENS (LH TENS) in the treatment of negative and sensory symptoms and motor deficiency in patients with diabetic distal polyneuropathy of the lower extremities with application of innovative scientific and technical complexes and scientific and research technology.…”