Transcutaneous electrical nerve stimulation for the treatment of acute postoperative pain following spine surgery: a scoping review

OBJECTIVE Given the ubiquity and severity of postoperative pain following spine surgery, developing adequate pain management modalities is critical. Transcutaneous electrical nerve stimulation (TENS) is a promising noninvasive modality that is well studied for managing postoperative pain following a variety of surgeries, but data on using TENS for pain management in the acute postoperative period of spine surgery are limited. Therefore, this review aimed to recapitulate the existing evidence for the use of TENS in postoperative pain management for spine surgery and explore the potential of this modality moving forward. METHODS A scoping review was conducted according to 2020 PRISMA guidelines. Two independently operating reviewers then conducted a systematic search of PubMed, Embase, and Scopus databases to identify studies that reported the use of TENS for the treatment of acute postoperative pain following spine surgery. The following data were abstracted from included studies: study type, sample size, demographics, surgery details, comparison group, assessment parameters, timing of postoperative assessment, TENS technical characteristics, relevant findings, length of hospital stay, complications with TENS, and notable limitations. RESULTS Nine hundred thirty-two publications were screened, resulting in 6 studies included in this review, all of which were prospective clinical trials. The publication dates ranged from 1980 to 2011. Spine surgery types varied; the most common was posterior lumbar interbody fusion. No studies evaluated pain control in cervical- or thoracic-only surgeries. All 6 studies evaluated the level of postoperative pain directly. Five of the 6 studies that directly examined postoperative pain reported lower levels of pharmacological analgesia usage in the TENS groups compared with controls, with 4 of these studies reporting this difference as statistically significant. Length of hospital stay was evaluated in 2 studies, both of which reported decreases in mean length of stay, but these differences were not significant. Notably, every study reported distinct TENS administration parameters while also reporting similar results. CONCLUSIONS This review concludes that TENS is effective at reducing postoperative pain in spine surgery. Further investigation is needed regarding the optimal settings for TENS administration, as well as efficacy in the thoracic and cervical spine.