title: The use of the Gait Deviation Index for the evaluation of participants following total hip arthroplasty: An explorative randomized trial.
abstract: BACKGROUND
  In this paper, the Gait Deviation Index (GDI) was used as a convenient method to evaluate pre-to-postoperative gait pattern changes after total hip arthroplasty and identify factors which might be predictive of outcome.
  
  
  METHODS
  Three-dimensional gait data from a randomized clinical trial was used to determine changes in gait quality in participants walking at self-selected speed. Upon completion of the first assessment, the participants were randomly assigned to either resurfacing hip arthroplasty or conventional hip arthroplasty. The outcome was changes in overall gait 'quality' measured with GDI during the 6-month post-surgery follow-up period.
  
  
  RESULTS
  38 participants with severe unilateral primary hip osteoarthritis took part in the trial. We found no difference in change scores between the two treatment groups; 1.9 [95%CI: -0.3 to 4.0] or between change scores for the non-operated and the operated limbs; 0.3 [95%CI: -2.3 to 1.7]. However, the score for the two groups (pooled data) improved after surgery by 4.4 [95%CI: 1.8-7.0]. The single level regression analysis identified the preoperative GDI score as a strong predictor of outcome (p<0.001).
  
  
  CONCLUSIONS
  Six months after surgery, there was no additional effect of resurfacing hip arthroplasty on GDI scores compared with conventional hip arthroplasty. Participants with the most pathological preoperative gait pattern improved the most. The GDI increased, which indicates an overall improvement in gait pathology after surgery.
  
  
  BACKGROUND
  NCT01229293.
authors.affiliation: Orthopedic Research Unit, Department of Orthopedic Surgery and Traumatology, Odense University Hospital, Odense C, Denmark; Institute of Clinical Research, University of Southern Denmark, Odense, Denmark. Electronic address: cjensen@health.sdu.dk.
authors.forename: Carsten
authors.initials: C
authors.lastname: Jensen
authors.affiliation: Orthopedic Research Unit, Department of Orthopedic Surgery and Traumatology, Odense University Hospital, Odense C, Denmark; Department of Orthopedic Surgery and Traumatology, Køge Hospital, Køge, Denmark. Electronic address: signe.rosenlund@gmail.com.
authors.forename: Signe
authors.initials: S
authors.lastname: Rosenlund
authors.affiliation: Orthopedic Research Unit, Department of Orthopedic Surgery and Traumatology, Odense University Hospital, Odense C, Denmark; Institute of Clinical Research, University of Southern Denmark, Odense, Denmark. Electronic address: dbnielsen@health.sdu.dk.
authors.forename: Dennis B
authors.initials: DB
authors.lastname: Nielsen
authors.affiliation: Orthopedic Research Unit, Department of Orthopedic Surgery and Traumatology, Odense University Hospital, Odense C, Denmark; Institute of Clinical Research, University of Southern Denmark, Odense, Denmark. Electronic address: Soeren.Overgaard@rsyd.dk.
authors.forename: Søren
authors.initials: S
authors.lastname: Overgaard
authors.affiliation: Orthopedic Research Unit, Department of Orthopedic Surgery and Traumatology, Odense University Hospital, Odense C, Denmark; Institute of Clinical Research, University of Southern Denmark, Odense, Denmark. Electronic address: AHLarsen@health.sdu.dk.
authors.forename: Anders
authors.initials: A
authors.lastname: Holsgaard-Larsen
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000503:physiopathology* / Q000601:surgery*; D011183:Postoperative Complications / Q000503:physiopathology*; D011184:Postoperative Period; D004856:Postural Balance / Q000502:physiology; D012044:Regression Analysis; D016138:Walking / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology
keywords: Gait; Gait Deviation Index; Hip arthroplasty; Osteoarthritis