title: Prospective dynamic functional evaluation of gait and spinal balance following spinal fusion in adolescent idiopathic scoliosis.
abstract: METHODS
  Prospective evaluation of gait and spinal-pelvic balance parameters in patients with adolescent idiopathic scoliosis undergoing a spinal fusion.
  
  
  OBJECTIVE
  To evaluate changes in gait and three-dimensional alignment and balance of the spine relative to the pelvis as a consequence of spinal fusion.
  
  
  BACKGROUND
  Preoperative and postoperative spinal radiographs have been the major forms of outcome analysis of adolescent idiopathic scoliosis fusions. The use of optoelectronic analysis for posture and gait has gained acceptance recently. However, there is a paucity of data quantifying, comparing, and correlating structural and functional changes in patients undergoing scoliosis fusion surgery including upright posture and gait.
  
  
  METHODS
  Thirty patients with adolescent idiopathic scoliosis undergoing an instrumented spinal fusion were prospectively evaluated. Coronal and sagittal vertical alignment was evaluated on radiographs (CVA-R, SVA-R), during upright posture (CVA-P and SVA-P), and during gait (CVA-G, SVA-G). Transverse plane alignment was evaluated by the acromion-pelvis angle during gait.
  
  
  RESULTS
  Gait speed was significantly decreased (P < 0.05) between preoperative (129 +/- 16 cm/sec) and 2-year postoperative (119 +/- 16 cm/sec) testing sessions. Decreasing gait speed was the result of significantly reduced cadence and decreased stride length. There were no significant differences for lower extremity kinematics over the entire gait cycle. Spinal-pelvic balance parameters showed significant improvement in mean CVA-R, CVA-G (P < 0.05), then unchanged CVA-P at 2 years postoperation. CVA-P was relatively unchanged while the mean CVA-G also showed significant improvement from preoperation (2.2 +/- 2.4 cm) to 2 years postoperation (1.3 +/- 1.3 cm)(P < 0.05). The mean SVA-R, SVA-P, and SVA-G were unchanged at 2 years postoperation (P > 0.05). The acromion-pelvis angle during gait at maximum shoulder rotation was statistically improved at 1 year (P = 0.002) and 2 years (P = 0.001) after surgery. Importantly, CVA-P correlated with CVA-G, and SVA-P correlated with SVA-G to the P < 0.05 level.
  
  
  CONCLUSIONS
  Patients with adolescent idiopathic scoliosis undergoing spinal fusion show slightly decreased gait speed at 2 years postoperation without any change in lower extremity kinematics. Spinal-pelvic balance parameters are improved in the coronal plane and unchanged in the sagittal plane radiographically and during standing posture and gait. Transverse plane parameters also are improved at maximum shoulder rotation during gait.
authors.affiliation: Human Performance Laboratory, Barnes-Jewish Hospital, St. Louis, Missouri 63110, USA. lenkel@msnotes.wustl.edu
authors.forename: L G
authors.initials: LG
authors.lastname: Lenke
authors.forename: J R
authors.initials: JR
authors.lastname: Engsberg
authors.forename: S A
authors.initials: SA
authors.lastname: Ross
authors.forename: A
authors.initials: A
authors.lastname: Reitenbach
authors.forename: K
authors.initials: K
authors.lastname: Blanke
authors.forename: K H
authors.initials: KH
authors.lastname: Bridwell
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D011446:Prospective Studies; D011859:Radiography; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation; D013131:Spine / Q000502:physiology*; D014743:Videotape Recording