Vertebral coplanar alignment: a standardized technique for three dimensional correction in scoliosis surgery: technical description and preliminary results in Lenke type 1 curves.
METHODS
Prospective multicentric study.


OBJECTIVE
To present the preliminary results of an innovative method for standardized correction of scoliosis, vertebral coplanar alignment (VCA), based on a novel concept: the relocation of vertebral axis in a single plane.


BACKGROUND
Normal standing spine has no rotation in coronal or transverse planes, therefore X and Z axis of vertebrae are in the same plane: they are coplanar. VCA intends to relocate these axis in one plane, correcting rotation and translation, while X axis are returned to its normal posterior divergence in sagittal plane in thoracic spine.


METHODS
Twenty-five consecutive adolescent idiopathic scoliosis patients (Lenke type 1) underwent posterior surgery with segmental pedicle screw fixation. Slotted tubes were attached to convex side screws. Two longitudinal rods were inserted through the end of tubes. Then, they were separated along the slots, driving the tubes into one plane, making the axis of the vertebrae coplanar and thus correcting transverse rotation and coronal translation. To obtain kyphosis, distal ends of the tubes were spread in thoracic spine. Correction was maintained by locking a definitive rod in the concave side, then tubes were retrieved and the convex side rod, inserted and tightened. Correction was assessed on preoperative and postoperative full-spine standing radiograph. Vertebral rotation was measured on computed tomography-scan and magnetic resonance imaging.


RESULTS
Preoperative average thoracic curves of 61 degrees were corrected to 16 degrees (73%). Preoperative average thoracolumbar curves of 39 degrees were corrected to 12 degrees (70%). Preoperative average thoracic apical rotation of 24 degrees was corrected to 11 degrees (56%). Preoperative average thoracic kyphosis of 18 degrees remained unchanged after surgery; however, no patients had kyphosis <10 degrees after surgery. Rib hump improved from 30 to 11 mm (65%). There were no perioperative complications.


CONCLUSIONS
VCA provided excellent correction of coronal and transverse planes with normalization of thoracic kyphosis in Lenke type 1 adolescent idiopathic scoliosis surgery.
Vallespir
Gabriel Pizà
GP
Servicio de Cirugía Ortopédica y Traumatología Infantil, Hospital Universitari Son Dureta, Palma de Mallorca, Spain. bielpiza@telefonica.net
Flores
Jesús Burgos
JB
Trigueros
Ignacio Sanpera
IS
Sierra
Eduardo Hevia
EH
Fernández
Pedro Doménech
PD
Olaverri
Juan Carlos Rodríguez
JC
Alonso
Manuel García
MG
Galea
Rafael Ramos
RR
Francisco
Antonio Pérez
AP
Rodríguez de Paz
Beatriz
B
Carbonell
Pedro Gutiérrez
PG
Thomas
Javier Vicente
JV
López
José Luís González
JL
Paulino
José Ignacio Maruenda
JI
Pitarque
Carlos Barrios
CB
García
Oscar Riquelme
OR
D000293:Adolescent; D000328:Adult; D001863:Bone Screws; D002648:Child; D005260:Female; D006801:Humans; D016268:Internal Fixators; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D019637:Orthopedic Procedures / Q000295:instrumentation* / Q000379:methods*; D011446:Prospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome