Article

To achieve optimal results after fusion for adolescent idiopathic scoliosis
(AIS), radiographic parameters must be aligned with motion and performance. The
effects of fusion on balance are poorly understood. Center of mass (COM)
excursion and instantaneous interaction with center of pressure (COP) provides
information about patients' balancing ability during gait.
This study
investigates the interaction between COM and COP (COM-COP) in AIS patients before
and one year after spine fusion and determines what radiographic goals predict
restoration of harmonious COM-COP. This was a prospective study that investigated
sixteen adolescents with AIS curvature >30 requiring surgical correction.
Clinical outcomes measures, X-rays, and 3D motion-capture gait analysis were
collected. Sagittal and coronal COM and COP offsets and inclination angles were
calculated from positional data. COM excursion was calculated as peak COM
displacement based on mediolateral and vertical deviation from a line fitted to
the patient's path. Radiographic parameters were measured to determine variables
predictive of change in COM excursion. Post-operatively, average COM peak
displacement decreased (42.6 to 13.1 mm, p=0.001) and COM peak vertical
displacement remained unchanged (17.0 to 16.3 mm, p=0.472). COM-COP inclination
angles reduced in the coronal, but not sagittal plane. Coronal lower extremity
peak inclination angles reduced (8.8 to 7.5 , p=0.025), correlating with C7
plumb-line offset (R=0.581, p=0.018). Thoracic Cobb, thoracic kyphosis, and C7
plumb-line were predictors of change in COM excursion. Mediolateral COM excursion
post-surgery may reflect an attempt to reduce kinetic demands with improved
spinal alignment. Although AIS correction has historically focused on the coronal
plane, sagittal parameters may be more important for motion than previously theorized.
CI - Copyright (c) 2014. Published by Elsevier B.V.

Langue : ANGLAIS