Evidence-Based Spine-Care Journal 2014; 05(02): 087-094
DOI: 10.1055/s-0034-1386752
Systematic Review
Georg Thieme Verlag KG Stuttgart · New York

Electrical Stimulation to Enhance Spinal Fusion: A Systematic Review

Paul Park1, Darryl Lau2, Erika D. Brodt3, Joseph R. Dettori3
  • 1Department of Neurological Surgery, University of Michigan Health System, Ann Arbor, Michigan, United States
  • 2Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States
  • 3Spectrum Research, Inc., Tacoma, Washington, United States
Further Information

Publication History

28 February 2014

12 May 2014

Publication Date:
24 September 2014 (online)

Abstract

Study Design Systematic review.

Clinical Questions Compared with no stimulation, does electrical stimulation promote bone fusion after lumbar spinal fusion procedures? Does the effect differ based on the type of electrical stimulation used?

Methods Electronic databases and reference lists of key articles were searched up to October 15, 2013, to identify randomized controlled trials (RCTs) comparing the effect of electrical stimulation to no electrical stimulation on fusion rates after lumbar spinal fusion for the treatment of degenerative disease. Two independent reviewers assessed the strength of evidence using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) criteria.

Results Six RCTs met the inclusion criteria. The following types of electrical stimulation were investigated: direct current (three studies), pulsed electromagnetic field (three studies), and capacitive coupling (one study). The control groups consisted of no stimulation (two studies) or placebo (four studies). Marked heterogeneity in study populations, characteristics, and design prevented a meta-analysis. Regardless of the type of electrical stimulation used, cumulative incidences of fusion varied widely across the RCTs, ranging from 35.4 to 90.6% in the intervention groups and from 33.3 to 81.9% in the control groups across 9 to 24 months of follow-up. Similarly, when stratified by the type of electrical stimulation used, fusion outcomes from individual studies varied, leading to inconsistent and conflicting results.

Conclusion Given the inconsistency in study results, possibly due to heterogeneity in study populations/characteristics and quality, we are unable to conclude that electrical stimulation results in better fusion outcomes compared with no stimulation. The overall strength of evidence for the conclusions is low.

Supplementary Material