title: A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty.
abstract: OBJECTIVE
  To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used.
  
  
  METHODS
  PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain.
  
  
  METHODS
  Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings.
  
  
  RESULTS
  A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them.
  
  
  CONCLUSIONS
  This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality.
authors.affiliation: Rehabilitation Sciences Research Department, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: David
authors.initials: D
authors.lastname: Beckwée
authors.affiliation: Gerontology and Frailty in Ageing Research Departments, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Ivan
authors.initials: I
authors.lastname: Bautmans
authors.affiliation: Rehabilitation Sciences Research Department, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Eva
authors.initials: E
authors.lastname: Swinnen
authors.affiliation: Rehabilitation Sciences Research Department, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Yorick
authors.initials: Y
authors.lastname: Vermet
authors.affiliation: Rehabilitation Sciences Research Department, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Nina
authors.initials: N
authors.lastname: Lefeber
authors.affiliation: Rehabilitation Sciences Research Department, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Lievens
authors.affiliation: Rehabilitation Sciences Research Department, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Vaes
keywords: Transcutaneous electric nerve stimulation; knee arthroplasty; pain