The H-Wave device is an effective and safe non-pharmacological analgesic for chronic pain: a meta-analysis.

INTRODUCTION: This meta-analysis was conducted to systematically review the efficacy and safety of the H-Wave (Electronic Waveform Lab, Inc, Huntington Beach, CA, USA) device and programme as a non-pharmacological analgesic treatment in chronic soft tissue inflammation and neuropathic pain. METHODS: Five studies related to pain relief, reduction in pain medication and increased functionality obtained with the H-Wave device were included in the analysis. Data were analysed using the random effects model, including adjustment to evaluate variability, size of study and bias in effect size. A total of 6535 participants were included in the meta-analysis; there were 8065 participants' outcomes measured due to multiple measurements per participant. RESULTS: The H-Wave device decreased pain ratings across various chronic soft tissue inflammation and neuropathic pain conditions. The mean weighted effect size was 0.59, and the estimated effect size variance was 0.00003 (95% confidence intervals [CI]: 0.580, 0.600). The H-Wave device also decreased the intake of pain medication in patients with various chronic soft tissue inflammation and neuropathic pain conditions. The mean weighted effect size was 0.56, and the estimated effect size variance was 0.000013 (95% CI: 0.553, 0.567). Patient functionality was also improved with use of the H-Wave device. The mean weighted effect size was 0.70, and the estimated effect size variance was 0.00002 (95% CI: 0.691, 0.709). A chi-square test for homogeneous effect sizes found highly significant (P<0.00001) variability, indicating a robust significant effect size for increased functionality relative to both pain relief and reduction in pain medication. There was little to no evidence of any adverse effects associated with the use of the H-Wave device. CONCLUSION: The findings indicate a moderate to strong effect of the H-Wave device in providing pain relief, reducing the requirement for pain medication and increasing functionality. The most robust effect was observed for improved functionality, suggesting that the H-Wave device may facilitate a quicker return to work and other related daily activities.

Randomized, prospective, and controlled clinical trial of pulsed electromagnetic field stimulation for cervical fusion.

BACKGROUND CONTEXT: Multilevel fusions, the use of allograft bone, and smoking have been associated with an increased risk of nonunion after anterior cervical discectomy and fusion (ACDF) procedures. Pulsed electromagnetic field (PEMF) stimulation has been shown to increase arthrodesis rates after lumbar spine fusion surgery, but there are minimal data concerning the effect of PEMF stimulation on cervical spine fusion. PURPOSE: To determine the efficacy and safety of PEMF stimulation as an adjunct to arthrodesis after ACDF in patients with potential risk factors for nonunion. STUDY DESIGN: A randomized, controlled, prospective multicenter clinical trial. PATIENT SAMPLE: Three hundred and twenty-three patients with radiographic evidence (computed tomography-myelogram [CT-myelo] or magnetic resonance imaging [MRI]) of a compressed cervical nerve root and symptomatic radiculopathy appropriate to the compressed root that had failed to respond to nonoperative management were enrolled in the study. The patients were either smokers (more than one pack per day) and/or were undergoing multilevel fusions. All patients underwent ACDF using the Smith-Robinson technique. Allograft bone and an anterior cervical plate were used in all cases. OUTCOME MEASURES: Measurements were obtained preoperatively and at each postoperative interval and included neurologic assessment, visual analog scale (VAS) scores for shoulder/arm pain at rest and with activity, SF-12 scores, the neck disability index (NDI), and radiographs (anteroposterior, lateral, and flexion-extension views). Two orthopedic surgeons not otherwise affiliated with the study and blinded to treatment group evaluated the radiographs, as did a blinded radiologist. Adverse events were reported by all patients throughout the study to determine device safety. METHODS: Patients were randomly assigned to one of two groups: those receiving PEMF stimulation after surgery (PEMF group, 163 patients) and those not receiving PEMF stimulation (control group, 160 patients). Postoperative care was otherwise identical. Follow-up was carried out at 1, 2, 3, 6, and 12 months postoperatively. RESULTS: The PEMF and control groups were comparable with regard to age, gender, race, past medical history, smoking status, and litigation status. Both groups were also comparable in terms of baseline diagnosis (herniated disc, spondylosis, or both) and number of levels operated (one, two, three, or four). At 6 months postoperatively, the PEMF group had a significantly higher fusion rate than the control group (83.6% vs. 68.6%, p=.0065). At 12 months after surgery, the stimulated group had a fusion rate of 92.8% compared with 86.7% for the control group (p=.1129). There were no significant differences between the PEMF and control groups with regard to VAS pain scores, NDI, or SF-12 scores at 6 or 12 months. No significant differences were found in the incidence of adverse events in the groups. CONCLUSIONS: This is the first randomized, controlled trial that analyzes the effects of PEMF stimulation on cervical spine fusion. PEMF stimulation significantly improved the fusion rate at 6 months postoperatively in patients undergoing ACDF with an allograft and an anterior cervical plate, the eligibility criteria being patients who were smokers or had undergone multilevel cervical fusion. At 12 months postoperatively, however, the fusion rate for PEMF patients was not significantly different from that of the control group. There were no differences in the incidence of adverse events in the two groups, indicating that the use of PEMF stimulation is safe in this clinical setting.