Abstract
Purpose
Clinical assessment of immediate in-brace effect of braces designed using CAD/CAM and FEM vs. only CAD/CAM for conservative treatment of AIS, using a randomized blinded and controlled study design.
Methods
Forty AIS patients were prospectively recruited and randomized into two groups. For 19 patients (control group), the brace was designed using a scan of patient’s torso and a conventional CAD/CAM approach (CtrlBrace). For the 21 other patients (test group), the brace was additionally designed using finite element modeling (FEM) and 3D reconstructions of spine, rib cage and pelvis (NewBrace). The NewBrace design was simulated and iteratively optimized to maximize the correction and minimize the contact surface and material.
Results
Both groups had comparable age, sex, weight, height, curve type and severity. Scoliosis Research Society standardized criteria for bracing were followed. Average Cobb angle prior to bracing was 27° and 28° for main thoracic (MT) and lumbar (L) curves, respectively, for the control group, while it was 33° and 28° for the test group. CtrlBraces reduced MT and L curves by 8° (29 %) and 10° (40 %), respectively, compared to 14° (43 %) and 13° (46 %) for NewBraces, which were simulated with a difference inferior to 5°. NewBraces were 50 % thinner and had 20 % less covering surface than CtrlBraces.
Conclusion
Braces designed with CAD/CAM and 3D FEM simulation were more efficient and lighter than standard CAD/CAM TLSO’s at first immediate in-brace evaluation. These results suggest that long-term effect of bracing in AIS may be improved using this new platform for brace fabrication.
Trial registration
NCT02285621.
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Acknowledgments
Project funded by the Natural Sciences and Engineering Research Council of Canada (RGPIN 239148-11) and the Canadian Institutes of Health Research (MOP-119455). Special thanks to Marie-Chantal Bolduc and Benoit Bissonnette from Orthèse-Prothèse Rive-Sud who contributed to the design and fabrication of the braces, and delivery to the patients.
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Conflict of interest
Research and development contract was obtained with Groupe Lagarrigue to develop and transfer a license of the simulation platform. Money was given to the university and the contract was not directly related to the presented RCT study. The RCT study presented in this paper was funded by a peer-reviewed grant from the Canadian Institutes of Health Research. The participating orthotists from Orthèse-Prothèse Rive-Sud received nothing of value to realize this study.
Ethical approval
All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional ethical research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
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Informed consent was obtained from all individual participants included in the study and their parents.
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Cobetto, N., Aubin, C.E., Parent, S. et al. Effectiveness of braces designed using computer-aided design and manufacturing (CAD/CAM) and finite element simulation compared to CAD/CAM only for the conservative treatment of adolescent idiopathic scoliosis: a prospective randomized controlled trial. Eur Spine J 25, 3056–3064 (2016). https://doi.org/10.1007/s00586-016-4434-3
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DOI: https://doi.org/10.1007/s00586-016-4434-3