title: Efficacy of electrical stimulation for spinal fusion: a meta-analysis of fusion rate.
abstract: BACKGROUND
  Many clinical studies have demonstrated the effectiveness of electrical stimulation as an adjunct to spinal arthrodesis. However, there is a paucity of comparative data among different electrical stimulation techniques.
  
  
  OBJECTIVE
  To compare the efficacy of three electrical stimulation methods for spinal fusion based on the literature review.
  
  
  METHODS
  Twenty-one articles, meeting all the inclusion criteria, were selected. A total of 1,381 patients were evaluated.
  
  
  METHODS
  Systematic literature review and meta-analysis.
  
  
  METHODS
  Fusion rates were determined using radiography or computed tomography.
  
  
  METHODS
  A systematic literature review was conducted on spinal fusion surgeries with the aid of electrical stimulation devices. Only studies applying radiography or computed tomography for fusion assessment were included. Study groups were divided based on electrical stimulation types and were further grouped by other patient characteristics. Pooled estimates and 95% confidence intervals (CIs) were calculated by random-effects meta-analysis.
  
  
  RESULTS
  The pooled fusion rate for all studies was 85% (95% CI, 79-90). There were 14 direct current, 1 capacitive coupling (CC), and 10 inductive coupling studies in our analysis, with combined fusion rate of 85% (95% CI, 76-91), 90% (95% CI, 83-95), and 85% (95% CI, 74-93), respectively. There were no statistically significant differences among the three electrical stimulation methods. Further subgroup analysis suggested that age, sex, smoking status, surgery type, fusion levels, fusion column, implant use, and graft type did not significantly influence the fusion rate.
  
  
  CONCLUSIONS
  The three types of electrical stimulation devices had similar clinical efficacy in promoting bone growth for spinal fusion. The results for CC stimulation should be applied with caution as only one relevant study was identified.
authors.affiliation: Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, 109 Xueyuanxi Rd, Wenzhou, Zhejiang 325000, China.
authors.forename: Nai F
authors.initials: NF
authors.lastname: Tian
authors.forename: Yao S
authors.initials: YS
authors.lastname: Wu
authors.forename: Xiao L
authors.initials: XL
authors.lastname: Zhang
authors.forename: Fang M
authors.initials: FM
authors.lastname: Mao
authors.forename: Hua Z
authors.initials: HZ
authors.lastname: Xu
authors.forename: Yong L
authors.initials: YL
authors.lastname: Chi
mesh_terms: D004599:Electric Stimulation Therapy / Q000379:methods*; D006801:Humans; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome
keywords: Efficacy; Electrical stimulation; Fusion rate; Meta-analysis; Spinal fusion