Predicting calvarial morphology in sagittal craniosynostosis

Abstract

Early fusion of the sagittal suture is a clinical condition called, sagittal craniosynostosis. Calvarial reconstruction is the most common treatment option for this condition with a range of techniques being developed by different groups. Computer simulations have a huge potential to predict the calvarial growth and optimise the management of this condition. However, these models need to be validated. The aim of this study was to develop a validated patient-specific finite element model of a sagittal craniosynostosis. Here, the finite element method was used to predict the calvarial morphology of a patient based on its preoperative morphology and the planned surgical techniques. A series of sensitivity tests and hypothetical models were carried out and developed to understand the effect of various input parameters on the result. Sensitivity tests highlighted that the models are sensitive to the choice of input parameter. The hypothetical models highlighted the potential of the approach in testing different reconstruction techniques. The patient-specific model highlighted that a comparable pattern of calvarial morphology to the follow up CT data could be obtained. This study forms the foundation for further studies to use the approach described here to optimise the management of sagittal craniosynostosis.

Figure 1

Preoperative (A), post-operative (B) and follow up (C) skull reconstructions of a sagittal synostosis patient. Sagittal (D), transverse (E) and coronal (F) cross-sections of the preoperative (blue), post-operative (yellow) and follow up (grey) skull reconstructions. Note (A–C) are not to the scale while (D–F) are to the correct scale.

Figure 2

In silico cases (1–3) versus in vivo follow up skull: sagittal, coronal and transverse cross-sections.

Figure 3

In silico cases (1–3) versus in vivo follow up skull: three-dimensional distance plots. The red sections highlight where the in silico models over-predicted the shape of the in vivo skull, while the blue areas indicate where the in silico models under-predicted the in vivo skull morphology. Each skull has been scaled individually with the maximum and minimum scores for the colour chart given under each case.

Figure 4

A comparison between the predicted contact pressure on the intracranial volume (brain) between the Case 1–3.