RESEARCH ARTICLE
Anterior Overgrowth in Primary Curves, Compensatory Curves and Junctional Segments in Adolescent Idiopathic Scoliosis Tom P. C. Schlösser1, Marijn van Stralen2, Winnie C. W. Chu3, Tsz-Ping Lam4, Bobby K. W. Ng4, Koen L. Vincken2, Jack C. Y. Cheng4, René M. Castelein1* 1 Department of Orthopaedic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands, 2 Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands, 3 Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, 4 Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
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* [email protected]
Abstract Introduction OPEN ACCESS Citation: Schlösser TPC, van Stralen M, Chu WCW, Lam T-P, Ng BKW, Vincken KL, et al. (2016) Anterior Overgrowth in Primary Curves, Compensatory Curves and Junctional Segments in Adolescent Idiopathic Scoliosis. PLoS ONE 11(7): e0160267. doi:10.1371/journal.pone.0160267 Editor: Alejandro A. Espinoza Orías, Rush University Medical Center, UNITED STATES Received: March 23, 2016 Accepted: July 15, 2016 Published: July 28, 2016 Copyright: © 2016 Schlösser et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The work was supported by Alexandre Suerman MD/PhD Programme, AOSpine 7th European Young Researcher Award, Medtronic Inc. research grant, K2M research grant. Competing Interests: The authors have declared that no competing interests exist.
Although much attention has been given to the global three-dimensional aspect of adolescent idiopathic scoliosis (AIS), the accurate three-dimensional morphology of the primary and compensatory curves, as well as the intervening junctional segments, in the scoliotic spine has not been described before.
Methods A unique series of 77 AIS patients with high-resolution CT scans of the spine, acquired for surgical planning purposes, were included and compared to 22 healthy controls. Non-idiopathic curves were excluded. Endplate segmentation and local longitudinal axis in endplate plane enabled semi-automatic geometric analysis of the complete three-dimensional morphology of the spine, taking inter-vertebral rotation, intra-vertebral torsion and coronal and sagittal tilt into account. Intraclass correlation coefficients for interobserver reliability were 0.98–1.00. Coronal deviation, axial rotation and the exact length discrepancies in the reconstructed sagittal plane, as defined per vertebra and disc, were analyzed for each primary and compensatory curve as well as for the junctional segments in-between.
Results The anterior-posterior difference of spinal length, based on “true” anterior and posterior points on endplates, was +3.8% for thoracic and +9.4% for (thoraco)lumbar curves, while the junctional segments were almost straight. This differed significantly from control group thoracic kyphosis (-4.1%; P
Anterior Overgrowth in Primary Curves, Compensatory Curves and Junctional Segments in Adolescent Idiopathic Scoliosis Tom P. C. Schlösser1, Marijn van Stralen2, Winnie C. W. Chu3, Tsz-Ping Lam4, Bobby K. W. Ng4, Koen L. Vincken2, Jack C. Y. Cheng4, René M. Castelein1* 1 Department of Orthopaedic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands, 2 Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands, 3 Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, 4 Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
a11111
* [email protected]
Abstract Introduction OPEN ACCESS Citation: Schlösser TPC, van Stralen M, Chu WCW, Lam T-P, Ng BKW, Vincken KL, et al. (2016) Anterior Overgrowth in Primary Curves, Compensatory Curves and Junctional Segments in Adolescent Idiopathic Scoliosis. PLoS ONE 11(7): e0160267. doi:10.1371/journal.pone.0160267 Editor: Alejandro A. Espinoza Orías, Rush University Medical Center, UNITED STATES Received: March 23, 2016 Accepted: July 15, 2016 Published: July 28, 2016 Copyright: © 2016 Schlösser et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The work was supported by Alexandre Suerman MD/PhD Programme, AOSpine 7th European Young Researcher Award, Medtronic Inc. research grant, K2M research grant. Competing Interests: The authors have declared that no competing interests exist.
Although much attention has been given to the global three-dimensional aspect of adolescent idiopathic scoliosis (AIS), the accurate three-dimensional morphology of the primary and compensatory curves, as well as the intervening junctional segments, in the scoliotic spine has not been described before.
Methods A unique series of 77 AIS patients with high-resolution CT scans of the spine, acquired for surgical planning purposes, were included and compared to 22 healthy controls. Non-idiopathic curves were excluded. Endplate segmentation and local longitudinal axis in endplate plane enabled semi-automatic geometric analysis of the complete three-dimensional morphology of the spine, taking inter-vertebral rotation, intra-vertebral torsion and coronal and sagittal tilt into account. Intraclass correlation coefficients for interobserver reliability were 0.98–1.00. Coronal deviation, axial rotation and the exact length discrepancies in the reconstructed sagittal plane, as defined per vertebra and disc, were analyzed for each primary and compensatory curve as well as for the junctional segments in-between.
Results The anterior-posterior difference of spinal length, based on “true” anterior and posterior points on endplates, was +3.8% for thoracic and +9.4% for (thoraco)lumbar curves, while the junctional segments were almost straight. This differed significantly from control group thoracic kyphosis (-4.1%; P
