title: Importance of pelvic compensation in posture and motion after posterior spinal fusion using CD instrumentation for idiopathic scoliosis.
abstract: METHODS
  Posture and motion analysis after a Cotrel-Dubousset instrumentation.
  
  
  OBJECTIVE
  To investigate the compensation role of pelvis.
  
  
  BACKGROUND
  Few existing studies found no compensation at the lower unfused level but did not investigate the pelvis.
  
  
  METHODS
  Thirty patients were analyzed before surgery then at short-, medium-, and long-term postoperative follow-up. Calibrated x-rays with three-dimensional reconstruction yielded quantification of pelvic parameters. Noninvasive optoelectronic system allowed analyzing subjects first in standing position, then during flexion-extension, lateral bending, and axial rotation. Skin markers were used to quantify three-dimensional orientation of the shoulders, trunk and pelvis, and their range of motion (ROM).
  
  
  RESULTS
  Ten patients among 21 had after surgery more than 5 degrees change of pelvic incidence. In flexion, global ROM decreased from preoperative to postoperative phase (P < 0.05). Global ROM variation was not correlated to that of lower unfused segment, while it was highly correlated to pelvic ROM variation (r = 0.78 at medium follow-up).
  
  
  CONCLUSIONS
  This study underlines the central role of pelvis in balance and motion of the patients before and after surgery.
authors.affiliation: Laboratoire de Biomécanique, ENSAM-CNRS, Paris, France. wafa.skalli@paris.ensam.fr
authors.forename: Wafa
authors.initials: W
authors.lastname: Skalli
authors.forename: Reinhard D
authors.initials: RD
authors.lastname: Zeller
authors.forename: Lotfi
authors.initials: L
authors.lastname: Miladi
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Bourcereau
authors.forename: Mélanie
authors.initials: M
authors.lastname: Savidan
authors.forename: François
authors.initials: F
authors.lastname: Lavaste
authors.forename: Jean
authors.initials: J
authors.lastname: Dubousset
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009984:Orthopedic Fixation Devices; D010388:Pelvis / Q000503:physiopathology*; D011184:Postoperative Period; D011187:Posture; D011859:Radiography; D016059:Range of Motion, Articular; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D013123:Spinal Fusion; D013131:Spine / Q000000981:diagnostic imaging / Q000503:physiopathology