title: Effect of Surgical Fusion on Volitional Weight-Shifting in Individuals With Adolescent Idiopathic Scoliosis.
abstract: Prospective.
  
  
  
  The goals of this study were to (1) evaluate the differences in weightbearing symmetry between individuals with adolescent idiopathic scoliosis (AIS) and typically developing controls; (2) observe the effect of posterior spinal fusion and instrumentation (PSFI) on volitional weight-shifting at 1 and 2 years postoperatively; and (3) evaluate whether lowest instrumented fusion level (ie, lowest instrumented vertebra [LIV]) in PSFI has an effect on volitional weight-shifting.
  
  
  
  Previous studies have conflicting findings with regard to the effect of scoliosis on postural control tasks as well as the effect of surgery. They have also noted an inconsistent effect of PSFI at different LIVs, with more distal LIVs exhibiting greater reductions in postoperative range of motion.
  
  
  
  The study was designed with an AIS group of 41 patients (8 males and 33 females) with AIS who underwent PSFI, along with a Control Group of 24 age-matched typically developing participants (12 male and 12 female). Both groups performed postural control tasks (static balance and volitional weight-shifting), with the AIS group repeating the tasks at 1 and 2 years postoperatively.
  
  
  
  At baseline, the AIS group showed increased weightbearing asymmetry than the Control Group (p = .01). The AIS group showed improvements in volitional weight-shifting at 2 years over baseline (p < .01). There was no effect of LIV on volitional weight-shifting by the second postoperative year.
  
  
  
  Individuals with AIS have greater weightbearing asymmetry but improved volitional weight-shifting over typically developing controls. PSFI improves volitional weight-shifting beyond preoperative baseline but does not differ significantly by LIV.
authors.affiliation: Department of Orthopaedic Surgery, Medical College of Wisconsin, Milwaukee, WI, USA; College of Engineering, Marquette University, Milwaukee, WI, USA; Motion Analysis Laboratory, Shriners Hospital for Children, Chicago, IL, USA. Electronic address: nikhil.kurapati@marquette.edu.
authors.forename: Nikhil T
authors.initials: NT
authors.lastname: Kurapati
authors.affiliation: Motion Analysis Laboratory, Shriners Hospital for Children, Chicago, IL, USA; Physical Therapy Program, College of Health Sciences, Midwestern University, Downers Grove, IL, USA.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Krzak
authors.affiliation: Motion Analysis Laboratory, Shriners Hospital for Children, Chicago, IL, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Graf
authors.affiliation: Motion Analysis Laboratory, Shriners Hospital for Children, Chicago, IL, USA.
authors.forename: Sahar
authors.initials: S
authors.lastname: Hassani
authors.affiliation: Division of Biostatistics, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Sergey
authors.initials: S
authors.lastname: Tarima
authors.affiliation: Motion Analysis Laboratory, Shriners Hospital for Children, Chicago, IL, USA; Division of Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Peter F
authors.initials: PF
authors.lastname: Sturm
authors.affiliation: Motion Analysis Laboratory, Shriners Hospital for Children, Chicago, IL, USA.
authors.forename: Kim
authors.initials: K
authors.lastname: Hammerberg
authors.affiliation: Motion Analysis Laboratory, Shriners Hospital for Children, Chicago, IL, USA.
authors.forename: Purnendu
authors.initials: P
authors.lastname: Gupta
authors.affiliation: College of Engineering, Marquette University, Milwaukee, WI, USA; Motion Analysis Laboratory, Shriners Hospital for Children, Chicago, IL, USA.
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Harris
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion; D016896:Treatment Outcome
keywords: Posterior instrumentation and fusion; Postural control; Scoliosis