Radiofrequency-based treatment in therapy-related clinical practice – a narrative review. Part I: acute conditions

Abstract

Background: Radiofrequency electromagnetic field (RFEMF or simply RF)-based electrophysical agents have been employed in therapy-related clinical practice for several decades. They are used to reduce pain and inflammation and enhance tissue healing. Although these agents have generally become less popular in contemporary therapy practice, surveys have shown that some of these modalities are still reasonably widely used. Aim: To review the evidence for the use of non-invasive low frequency RFs (30 kHz-30 MHz) in therapy-related clinical practice. Methods: All peer reviewed therapy-related clinical studies published in English and concerning low frequency RF were sought. Identified literature was divided into acute and chronic segments based on their clinical area and analysed to assess the volume and scope of current evidence. The studies on acute conditions were reviewed in detail for this paper. Results: 120 clinical studies were identified, of which 30 related to acute conditions. The majority of studies employed Pulsed Shortwave Therapy (PSWT). Twenty two studies out of 30 were related to conditions of pain and inflammation, seven to tissue healing and one to acute pneumothorax. No studies were identified on frequencies other than shortwave. Conclusions: Evidence for and against RF-based therapy is available. There is reasonable evidence in support of PSWT to alleviate postoperative pain and promote postoperative wound healing. Evidence for other acute conditions is sparse and conflicting. A general lack of research emphasis in the non-shortwave RF band is evident, with studies on acute conditions almost non-existent. Further and wider research in this area is warranted.

Treatment using 448 kHz capacitive resistive monopolar radiofrequency improves pain and function in patients with osteoarthritis of the knee joint: a randomised controlled trial

“…Besides SWT which commonly operates at 27.12 MHz, other radiofrequency (RF)-based EPAs employing significantly lower operating frequencies (<1 MHz) have also been reported for the treatment of OA knee, despite their evidence base being minimal [22,23]. Capacitive Resistive Monopolar Radiofrequency (CRMRF) that operates at 448 kHz is an example.…”

Continuous-mode 448 kHz capacitive resistive monopolar radiofrequency induces greater deep blood flow changes compared to pulsed mode shortwave: a crossover study in healthy adults

“…Two recent reviews on the use of radiofrequency-based EPAs in therapy-related clinical practice published by the same authors found no clinical studies on acute conditions for frequencies below shortwave (23) and only a limited number of such studies on chronic conditions (26). The current study addressed the issue of physiological effects of both types of frequency ranges of RF by performing due comparisons between CRMRF that operates at 448 kHz in continuous mode and PSWT that operates at 27 MHz in pulsed mode.…”

“…Since CRMRF was shown to substantially increase and sustain skin temperature in our previously reported study (16), it was hypothesised that similar significant effects may be obtained on deep blood flow and tissue extensibility. The 5 results of this study are expected to provide important insight into the mode of action of low frequency RF-based EPAs such as CRMRF that has largely remained unexplored (23,26).…”

“…The RF frequency ranges used in physiotherapy are largely limited to 30 kHz-30 MHz (23)(24)(25)(26). Within this range the main EPA used is shortwave therapy (SWT), which commonly operates at 27.12 MHz, either in continuous (CSWT) or pulsed (PSWT) mode although it is 4 largely limited to PSWT in contemporary practice (25,27).…”

Analysis of electric field and emission spectrum in the glow discharge of therapeutic plasma electrode

“…Medical appliances using low-tomoderate intensity radio-frequency electromagnetic fields (RF-EMF) in the range from 30 kHz to 300 MHz are commonly used in the treatment of bone fractures, wounds or pain, and oedema [44]. Kumaran and Watson [47,48], in their review articles (120 reports) on therapeutic effects of RF-EMF, listed numerous clinical studies reporting positive effects in reduction of pain, oedema, erythema, inflammatory processes, stimulation of healing and re-establishment of function, as well as reduced analgesic drug intake and reduced length of hospitalization. Al-Badavi et al [49] also reported application of pulsed radio-frequency (impulse frequency 600 Hz, pulse modulation 250 kHz) as safe and effective treatment for TMJ arthralgia and increasing mandibular range of motion.…”