Background

Spring-Assisted Posterior Vault Expansion has been adopted at Great Ormond Street Hospital for Children, London, UK to treat raised intracranial pressure in patients affected by syndromic craniosynostosis, a congenital calvarial anomaly which causes premature fusion of skull sutures. This procedure aims at normalising head shape and augmenting intracranial volume by means of metallic springs which expand the back portion of the skull. The aim of this study is to create and validate a 3D numerical model able to predict the outcome of spring cranioplasty in patients affected by syndromic craniosynostosis, suitable for clinical adoption for preoperative surgical planning.

Methods

Retrospective spring expansion measurements retrieved from x-ray images of 50 patients were used to tune the skull viscoelastic properties for syndromic cases. Pre-operative computed tomography (CT) data relative to 14 patients were processed to extract patient-specific skull shape, replicate surgical cuts and simulate spring insertion. For each patient, the predicted finite element post-operative skull shape model was compared with the respective post-operative 3D CT data.

Findings

The comparison of the sagittal and transverse cross-sections of the simulated end-of-expansion calvaria and the post-operative skull shapes extracted from CT images showed a good shape matching for the whole population. The finite element model compared well in terms of post-operative intracranial volume prediction (R² = 0.92, p < 0.0001).

Interpretation

These preliminary results show that Finite Element Modelling has great potential for outcome prediction of spring assisted posterior vault expansion. Further optimisation will make it suitable for clinical deployment.

中文翻译：

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验证弹簧辅助后拱顶扩展结果预测的计算机模拟平台

背景

英国伦敦大奥蒙德街儿童医院采用了弹簧辅助后穹窿扩张，以治疗患有综合征性颅缝早闭症患者的颅内压升高，这是一种先天性颅骨异常，会导致颅骨缝合线过早融合。该程序旨在通过扩张颅骨后部的金属弹簧使头部形状正常化并增加颅内容量。本研究的目的是创建和验证一个 3D 数值模型，该模型能够预测受综合征性颅缝早闭影响的患者春季颅骨成形术的结果，适用于临床采用术前手术计划。

方法

从 50 名患者的 X 射线图像中检索到的回顾性弹簧膨胀测量值用于调整综合征病例的颅骨粘弹性。对 14 名患者的术前计算机断层扫描 (CT) 数据进行了处理，以提取患者特定的颅骨形状、复制手术切口并模拟弹簧插入。对于每位患者，将预测的有限元术后颅骨形状模型与各自的术后 3D CT 数据进行比较。

发现

比较模拟的扩张末期颅骨的矢状断面和横断面与从 CT 图像中提取的术后颅骨形状，表明整个人群的形状匹配良好。有限元模型在术后颅内体积预测方面比较好（R ²  = 0.92，p  < 0.0001）。

解释

这些初步结果表明，有限元建模对于弹簧辅助后拱顶扩张的结果预测具有巨大潜力。进一步优化将使其适合临床部署。