Comparison of four correction techniques for posterior spinal fusion in adolescent idiopathic scoliosis

• Published in: European spine journal Vol. 31; no. 4; pp. 1028 - 1035
• Main Authors: Pesenti, Sebastien, Clément, Jean-Luc, Ilharreborde, Brice, Morin, Christian, Charles, Yann Philippe, Parent, Henri François, Violas, Philippe, Szadkowski, Marc, Boissière, Louis, Jouve, Jean-Luc, Solla, Federico
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2022; Springer Nature B.V
• Subjects: Adolescent; Back surgery; Compression; Humans; Kyphosis; Kyphosis - surgery; Medicine; Medicine & Public Health; Multivariate analysis; Neurosurgery; Original Article; Patients; Pedicle Screws; Retrospective Studies; Scoliosis; Scoliosis - diagnostic imaging; Scoliosis - surgery; Spinal Fusion - methods; Surgical Orthopedics; Thoracic Vertebrae - diagnostic imaging; Thoracic Vertebrae - surgery; Thorax; Treatment Outcome; Adolescent idiopathic surgery; Reduction technique; Thoracic kyphosis; Surgery
• ISSN: 0940-6719; 1432-0932
• DOI: 10.1007/s00586-022-07145-7

Introduction
When performing posterior spinal fusion for adolescent idiopathic scoliosis (AIS), it is of major importance to address both coronal and sagittal deformities. Although several techniques have been described, few data exist comparing them. Our objective was to compare four techniques (in situ bending (ISB), rod derotation (RD), cantilever (C) and posteromedial translation (PMT)) for the correction of spinal deformity in AIS including thoracic deformity.
Material and methods
We conducted a multicenter retrospective study including 562 AIS patients with thoracic deformity with at least 24-month follow-up. Radiographic analysis was performed preoperatively, postoperatively and at last follow-up. The main outcomes were main curve correction and thoracic kyphosis restoration (TK).
Results
Coronal correction rate was significantly different among the four treatment groups (ISB 64% vs C 57% vs RD 55% vs PMT 67%,
p
 < 0.001). Multivariate regression revealed that correction technique did not influence correction rate, whereas implant density, convex side compression and use of derotation connectors did. TK increase was significantly higher in the PMT group (average + 13°) than in DR (+ 3°), while ISB (−3°) and cantilever (−13°) resulted in TK decrease (
p
 < 0.001). Multivariate analysis revealed that TK increase was only influenced by the reduction technique (
p
 < 0.001) and preoperative TK (
p
 < 0.001).
Discussion
The four techniques had the same ability to correct spinal deformity in the coronal plane. Three factors were identified to improve correction rate: implant density, convex compression and use of derotation connectors. On the other hand, PMT was more effective in restoring TK, particularly in hypokyphotic patients.