Diathermy and TECAR Therapy for Lateral Elbow Tendinopathy: A Systematic Review of Randomized Controlled Trials

Abstract Background Lateral elbow tendinopathy is a common musculoskeletal disorder characterized by pain and functional limitations of the upper limb. Deep thermotherapy modalities, such as shortwave diathermy and TECAR therapy, are increasingly used in clinical practice; however, their effectiveness remains unclear. Objective To evaluate the effectiveness of diathermy-based interventions, including TECAR therapy, in the management of lateral elbow tendinopathy, with a focus on pain and functional outcomes. Methods A systematic review was conducted in accordance with PRISMA 2020 guidelines. Electronic databases (PubMed and Scopus) were searched from inception to January 2026, and Google Scholar was used as an additional source to identify potentially relevant studies. Randomized controlled trials investigating diathermy-based interventions in patients with lateral elbow tendinopathy were included. Study selection, data extraction, and methodological quality assessment were performed independently by two reviewers using the PEDro scale and the Cochrane RoB 2 tool. Results Two randomized controlled trials ( n = 96) were included. In the study evaluating TECAR therapy, no statistically significant between-group differences were observed for pain outcomes ( p > 0.05), whereas functional outcomes (DASH) favored the intervention group. In contrast, continuous shortwave diathermy combined with exercise therapy demonstrated greater improvements in pain, functional outcomes, and grip strength compared with the control group. However, effect sizes and measures of variability were not consistently reported across studies, limiting the assessment of the magnitude and clinical relevance of these findings. Conclusion The current evidence is limited and of low certainty. Due to the small number of studies, heterogeneity of interventions, and lack of consistent quantitative reporting, no firm conclusions can be drawn regarding the effectiveness or clinical applicability of diathermy-based modalities. These interventions should be considered investigational, and further high-quality randomized controlled trials are required.