Effects of percutaneous microelectrolysis (MEP ® ) on pain, rom and morning stiffness in patients with achilles tendinopathy

Abstract

Background Achilles tendinopathy is the third most common disease in the musculoskeletal system. Histopathological evidence indicates that tendinopathies are typically degenerative lesions, presenting collagen fibre separation and disorganisation, mucoid substance increase, hyperplasia and presence of necrotic tissue. There is also an increase in fibroblasts and an absence of acute inflammatory cells. Normally, an intratendinous nodule can be found by palpation or diagnostic ultrasound at 2-6 cm from distal insertion. This disorder is clinically characterised by pain and stiffness. These symptoms are initially present only in the morning, during the warm up, or after physical activities. In a later phase, pain is more persistent and, may appear during exercise, interfering with activities of daily living, and compromising ankle range of motion. To assess the Achilles tendinopathy, the Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire is often used. It is a validated questionnaire, simple, practical and easy to apply. It consists of eight questions to assess the severity of the tendinopathy symptoms, functional capacity and the ability to play sports. To assess Range of Motion (ROM), goniometry is often used. To assess pain, the Visual Analogue Scale (VAS) is often used. Physical therapy plays an important role in symptom reduction and in function recovery. There are several methods suggested for tendinopathy treatment. The conservative medical treatment often consists of pain and anti-inflammatory drugs. There are many resources in physical therapy, including different electrotherapy modalities, such as ultrasound, low level laser therapy, iontophoresis and extracorporeal shock wave therapy. In the last few years, new technologies have been proposed to treat tendinopathies. One of them is Percutaneous Microelectrolysis (MEP® ). This technique employs a galvanic current up to 990 uA (microamperes), which is applied percutaneously with an acupuncture needle connected to the cathode. In a histological research in animals, MEP® was applied in muscle tissue producing a high acute inflammatory response with a large number of inflammatory cells (mainly neutrophils), oedema and injury in muscle fibres. These effects are caused by the cathodic galvanic current that MEP® uses. Tissue destruction occurs through alkalosis, promoting new tissue formation due to the stimulation of inflammatory and regeneration phases. This treatment also produces a H2 gas release, which is a powerful free radical inhibitor that promotes analgesia. It is believed that the same effects can be found in tendinous tissues. Purpose The aim of this study was to evaluate the effects of MEP® on pain, range of motion (ROM) and matinal stiffness in patients with Achilles tendinopathy. Methods This randomised controlled clinical trial was carried out in Clínicas Integradas da Universidade Potiguar. Twenty patients with Achilles tendinopathy that accepted to participate in this research were randomly divided into two groups: Control Group (G1): (1) Warm up with a stationary bike for 10 min; (2) Stretching adductors, abductors, hamstrings and plantar flexors (3×30), two minutes rest between sets; (3) Friction massage of the Achilles tendon; (4) Stretching of the plantar fascia; (5) Eccentric exercises for plantar flexors (3 sets ×15 reps). The treatment was applied twice a week for a month (eight sessions in total). Treatment Group (G2): Same protocol as G1, plus MEP® once a week. MEP® (Fisiomove) was used as follows: (1) Disinfection of the treatment zone with alcohol at 70%; (2) A 0.22×13mm needle was introduced 11 mm, three times during each session, at different points in the Achilles tendon, in collagen fibres direction, with an initial intensity of 100 lA (microamperes); (3) The intensity was increased up to 450 lA (microamperes), achieving a current density of 5,86 mA/cm2. MEP® was turned on for 20 s, followed by a 40 s resting time, totalling to 3 min. To assess the response to the treatments, the question related to morning stiffness in the VISA-A questionnaire, goniometry and Visual Analogue Scale (VAS) were used. VAS was assessed before and after each session. Data was analysed using Paired and Independent T test, with a significance level of 5%, with SPSS 20. Results The intragroup statistical comparison showed that before and after 8 sessions, a significant reduction of morning stiffness duration in the Control Group (G1) (p