Piezosurgical Suturectomy and Sutural Distraction Osteogenesis for the Treatment of Unilateral Coronal Synostosis

Computational modelling of patient specific spring assisted lambdoid craniosynostosis correction

Lambdoid craniosynostosis (LC) is a rare non-syndromic craniosynostosis characterised by fusion of the lambdoid sutures at the back of the head. Surgical correction including the spring assisted cranioplasty is the only option to correct the asymmetry at the skull in LC. However, the aesthetic outcome from spring assisted cranioplasty may remain suboptimal. The aim of this study is to develop a parametric finite element (FE) model of the LC skulls that could be used in the future to optimise spring surgery. The skull geometries from three different LC patients who underwent spring correction were reconstructed from the pre-operative computed tomography (CT) in Simpleware ScanIP. Initially, the skull growth between the pre-operative CT imaging and surgical intervention was simulated using MSC Marc. The osteotomies and spring implantation were performed to simulate the skull expansion due to the spring forces and skull growth between surgery and post-operative CT imaging in MSC Marc. Surface deviation between the FE models and post-operative skull models reconstructed from CT images changed between ± 5 mm over the skull geometries. Replicating spring assisted cranioplasty in LC patients allow to tune the parameters for surgical planning, which may help to improve outcomes in LC surgeries in the future.

Computational Evaluation of Potential Correction Methods for Unicoronal Craniosynostosis

Unicoronal craniosynostosis is the second most common type of nonsyndromic craniosynostosis: it is characterized by ipsilateral forehead and fronto-parietal region flattening with contralateral compensatory bossing. It is a complex condition; therefore, which is difficult to treat because of the asymmetry in the orbits, cranium, and face. The aim of this study is to understand optimal osteotomy locations, dimensions, and force requirements for surgical operations of unicoronal craniosynostosis using a patient-specific finite element model and - at the same time - to evaluate the potential application of a new device made from Nitinol which was developed to expand the affected side of a unicoronal craniosynostosis skull without performing osteotomies. The model geometry was reconstructed using Simpleware ScanIP. The bone and sutures were modeled using elastic properties to perform the finite element analyses in MSc Marc software. The simulation results showed that expanding the cranium without osteotomy requires a significant amount of force. Therefore, expansion of the cranium achieved by Nitinol devices may not be sufficient to correct the deformity. Moreover, the size and locations of the osteotomies are crucial for an optimal outcome from surgical operations in unicoronal craniosynostosis.

Craniofacial Distraction in the Management of Anterior Plagiocephaly: A Novel Idea and a Systematic Review of the Literature

BACKGROUND

The objective of this work is to present a review of all reports involving the management of unicoronal synostosis with distraction osteogenesis (DO). Also, we have innovated a new method in the treatment of cases of anterior plagiocephaly at a young age using DO.

METHODS

We present a case in which anterior plagiocephaly was treated by DO of both metopic and hemicoronal sutures in a 4-month-old female patient. A comprehensive systematic literature review was completed using the search terms "distraction osteogenesis," "unicoronal synostosis," "anterior plagiocephaly," and "craniosynostosis." We excluded all experimental articles and reviewed clinical reports detailing the use of DO in the management of unicoronal synostosis.

RESULTS

The study sample of this review consisted of 16 reports published over a period of 17 years that were analyzed in detail. The total number of patients treated by DO was 120, and the mean age at operation was 12 months. In the case presented, successful correction of the unicoronal synostosis was achieved.

CONCLUSION

Hemicoronal and metopic suture distraction in anterior plagiocephaly achieves considerable improvement in the midline shift of the anterior cranial base and naso-orbital complex.