Towards a radiation free numerical modelling framework to predict spring assisted correction of scaphocephaly

Garate Andikoetxea, Begona; Ajami, Sara; Rodriguez-Florez, Naiara; Jeelani, N. U. Owase; Dunaway, David; Schievano, Silvia; Borghi, Alessandro

Abstract

Sagittal Craniosynostosis (SC) is a congenital craniofacial malformation, involving premature sagittal suture ossification; spring-assisted cranioplasty (SAC) - insertion of metallic distractors for skull reshaping - is an established method for treating SC. Surgical outcomes are predictable using numerical modelling, however published methods rely on computed tomography (CT) scans availability, which are not routinely performed. We investigated a simplified method, based on radiation-free 3D stereophotogrammetry scans.Eight SAC patients (age 5.1 ± 0.4 months) with preoperative CT and 3D stereophotogrammetry scans were included. Information on osteotomies, spring model and post-operative spring opening were recorded. For each patient, two preoperative models (PREOP) were created: i) CT model and ii) S model, created by processing patient specific 3D surface scans using population averaged skin and skull thickness and suture locations. Each model was imported into ANSYS Mechanical (Analysis System Inc., Canonsburg, PA) to simulate spring expansion. Spring expansion and cranial index (CI - skull width over length) at times equivalent to immediate postop (POSTOP) and follow up (FU) were extracted and compared with in-vivo measurements.Overall expansion patterns were very similar for the 2 models at both POSTOP and FU. Both models had comparable outcomes when predicting spring expansion. Spring induced CI increase was similar, with a difference of 1.2%±0.8% for POSTOP and 1.6%±0.6% for FU.This work shows that a simplified model created from the head surface shape yields acceptable results in terms of spring expansion prediction. Further modelling refinements will allow the use of this predictive tool during preoperative planning.

Citation

Garate Andikoetxea, B., Ajami, S., Rodriguez-Florez, N., Jeelani, N. U. O., Dunaway, D., Schievano, S., & Borghi, A. (online). Towards a radiation free numerical modelling framework to predict spring assisted correction of scaphocephaly. Computer Methods in Biomechanics and Biomedical Engineering, https://doi.org/10.1080/10255842.2023.2294262

• Journal Article Type: Article
• Acceptance Date: Dec 8, 2023
• Online Publication Date: Dec 18, 2023
• Deposit Date: Dec 19, 2023
• Publicly Available Date: Jun 14, 2024
• Journal: Computer Methods in Biomechanics and Biomedical Engineering
• Print ISSN: 1025-5842
• Electronic ISSN: 1476-8259
• Publisher: Taylor and Francis Group
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1080/10255842.2023.2294262
• Keywords: Finite element modelling, craniosynostosis, spring cranioplasty
• Public URL: https://durham-repository.worktribe.com/output/2047992