Transcutaneous electrical nerve stimulation as adjunct to primary care management for tennis elbow: pragmatic randomised controlled trial (TATE trial)

Transcutaneous electrical nerve stimulation (TENS) which is a noninvasive treatment, is primarily used to reduce pain. One randomised controlled trial showed TENS could relieve pain for patients with tennis elbow compared with sham TENS [1]. And previous meta-analysis also indicated that TENS was effective for the management of the patients with chronic musculoskeletal pain [2]. However, Chesterton and colleagues’ multicentre randomised clinical trial did not support the use of TENS for tennis elbow [3]. Therefore, we conducted a meta-analysis (Registration: PROSPERO CRD42013005682) to assess the effects of TENS for tennis elbow.

Relevant randomised clinical trials were identified by electronically searching the following data sources (up to September, 2013): Medline, Embase, Web of Science, the Cochrane Library, PEDro, CINAHL, China Biology Medicine disc. Keywords related to epicondylitis such as ‘epicondylitis’, ‘tennis elbow’, ‘physical therapy’, ‘electrotherapy’, and ‘TENS’ were included. We included patients with tennis elbow in the systematic review. And we only considered these trials that compared a treatment group, which received TENS, and a control group, which performed sham TENS, other interventions or no intervention. Primary outcome measure is pain intensity. The Physiotherapy Evidence Database scale [4] was used to assess the risk of bias for included trails in the systematic review.

Two randomised controlled trials [1, 3] of 301 patients met the inclusion criteria for the meta-analysis. According to Physiotherapy Evidence Database scale, one trail 1 including 60 patients is low quality (PEDro score=3), another trail 3 including 241 patients is high quality (PEDro score=8). The pooling revealed that TENS was not superior to control group for pain relief [SMD (95% CI) = -0.09 (-0.37, 0.19), p=0.55]. In all subgroups, there were no significant differences between TENS and control group at the end of the intervention [SMD (95% CI) = -0.37 (-1.40, 0.66), p=0.48], intermediate term [SMD (95% CI) = 0.10 (-0.15, 0.36), p=0.42] and long term [SMD (95% CI) = -0.11 (-0.36, 0.15), p=0.41]. See figure 1.

The current evidence indicates TENS did not provide additional benefit for relieving pain compared to control group. However, the number of included studies and the sample size of subjects in this meta-analysis were small. Therefore, some large-scale randomised clinical trials are needed. To evaluate how long any improvement intervention may last based on TENS, we need more trails for follow-up sessions with longer durations in tennis elbow. In addition, there are different frequencies in use for TENS, which could lead to different results in tennis elbow. Hence, it is necessary to perform a meta-analysis of different frequencies of TENS to determine the optimal intervention approach in tennis elbow.

Xue-Qiang Wang, Pei-Jie Chen*
Key Laboratory of Exercise and Health Sciences, Ministry of Education, Shanghai University of Sport, Shanghai, China
Correspondence to: Pei-Jie Chen, chenpeijie@sus.edu.cn.

References
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2. Johnson M, Martinson M. Efficacy of electrical nerve stimulation for chronic musculoskeletal pain: a meta-analysis of randomized controlled trials. Pain 2007;130:157-65.
3. Chesterton LS, Lewis AM, Sim J, Mallen CD, Mason EE, Hay EM, van der Windt DA. Transcutaneous electrical nerve stimulation as adjunct to primary care management for tennis elbow: pragmatic randomised controlled trial (TATE trial). BMJ 2013; 347:f5160.
4. Pinto RZ, Maher CG, Ferreira ML, Hancock M, Oliveira VC, McLachlan AJ, Koes B, Ferreira PH. Epidural corticosteroid injections in the management of sciatica: a systematic review and meta-analysis. Ann Intern Med. 2012;157:865-77.