Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Alleviation in Perioperative Fracture Patients

Transcutaneous electrical nerve stimulation (TENS) is an affordable and non-invasive option for post-operative analgesia. Broadly, TENS devices deliver pulsed electrical impulses across skin to modulate pain. They are theorized to work through different mechanisms at multiple physiologic levels. Centrally, TENS units activate small-diameter sensory afferents (Aδ nerve fibers), which in turn activate descending pain-inhibitory networks. Peripherally, TENS activation of both large- and small-diameter sensory afferents blocks nociceptive signals to the brain and is instead perceived as TENS-induced paresthesias. Finally, TENS efficacy may also be mediated by µ-opioid, 5-hydroxytryptamine (HT)-1, and 5-HT-2 receptors, particularly at low-frequency electrical activity.2

There are inconclusive results for the adjunctive use of TENS to modulate pain, largely because of a relative paucity of high-quality trials and significant inter-study heterogeneity due to non-standardized protocols. Moreover, most studies within the orthopaedic literature have been concentrated primarily within the total knee arthroplasty (TKA) literature and may have limited generalizability to orthopaedic trauma patients. Some studies have shown a trend towards decreased opioid consumption with the adjunctive use of TENS (vs. placebo-TENS or standard care)3,4 while other studies have shown no difference in pain scores in the post-operative period.5-8 To the investigator's knowledge, only two recent randomized clinical trial (RCT)s have been conducted on non-TKA orthopaedic populations, both of which show promise for the use of TENS postoperatively. One prospective double-blind randomized trial on arthroscopic rotator cuff repairs found a 25% reduction in post-operative opioid consumption when TENS was used adjunctively for pain control .9 Another single-blind prospective RCT on Colles' fractures reported greater postoperative pain improvements in patients receiving TENS vs. placebo.10

There is a growing body of evidence to suggest that TENS therapy can reduce post-operative pain after orthopedic procedures. More high-quality studies are needed to strengthen this suggestion and to characterize specific protocols, populations, and orthopedic conditions for which it might work best. Transcutaneous electrical nerve stimulation, if shown to be effective, stands to serve as an affordable non-opioid, non-invasive option for the safe and effective treatment of pain in the orthopaedic trauma patient population.

TENS units are a non-significant risk device and, therefore, do not require an investigational device exemption (IDE) based upon FDA guidance.15-17 The sensor pads will be placed at the same time as the surgical fixation of the study injury. It does not present a potential serious risk to the health and welfare of patients.

Specific Aim 1: To pilot the use of TENS among a postoperative lower extremity injury population as part of multimodal pain management.