The change on vertebral axial rotation after posterior instrumentation of idiopathic scoliosis.
OBJECTIVE
Agreement between the correction objectives and the instrumentation strategies remains controversial in idiopathic scoliosis. Most studies have focus on the frontal and sagittal plane. The goal of this study was to evaluate the change on vertebral axial rotation after posterior instrumentation in fused and unfused segments.


METHODS
Fourteen patients operated on for idiopathic scoliosis were prospectively included. Fusion and instrumentation were done by posterior approach. All patients had a pre-operative and a 10-day post-operative radiological evaluation with the EOS system. Axial orientation of the vertebrae with special interest to the apical, junctional, and unfused areas was obtained thanks to the reconstruction software.


RESULTS
Mean apical vertebra axial rotation statistically decreased from 21° pre-operatively to 13° post-operatively. But, there were no statistically significant differences between pre-operative and post-operative mean axial intervertebral rotations in the main curve and axial rotation of the non-instrumented lower counter curve.


CONCLUSIONS
3D analysis of the spine in standing position is a great advancement for post-operative analysis of adolescent idiopathic scoliosis (AIS) corrections. This study confirmed that actual instrumentations are able to achieve "en bloc" 3D correction of the spine but not intervertebral axial rotation correction.
Department of Paediatric Orthopaedics, Grenoble University Hospital, Grenoble Alpes University, TIMC-IMAG-SPM, . aurelien.courvoisier@gmail.com.|Department of Paediatric Orthopaedics, Hôpital Couple Enfant, BP 217 38043, Cedex 09 Grenoble, France. aurelien.courvoisier@gmail.com.
Aurélien
A
Courvoisier
Department of Paediatric Orthopaedics, Hôpital Femme-Mère-Enfant, Université Lyon 1, Lyon-Bron, 69500, France.
Christophe
C
Garin
Department of Paediatric Orthopaedics, Armand Trousseau Hospital, Université Pierre et Marie Curie-Paris, 6, 26, avenue du Docteur Arnold Netter, 75571, Paris Cedex 12, France.
Raphaël
R
Vialle
Department of Paediatric Orthopaedics, Hôpital Femme-Mère-Enfant, Université Lyon 1, Lyon-Bron, 69500, France.
Rémi
R
Kohler
D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019637:Orthopedic Procedures / Q000295:instrumentation / Q000379:methods*; D011859:Radiography; D012399:Rotation; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome
3D analysis; Adolescent idiopathic scoliosis; Instrumentation strategy; Preoperative planning; Stereoradiography