Proof of Concept Study for the Design, Manufacturing, and Testing of a Patient-Specific Shape Memory Device for Treatment of Unicoronal Craniosynostosis

Virtual Coordinate System in Unicoronal Synostosis

We propose a landmark-based, virtual coordinate system, specifically designed for assessment of asymmetrical craniofacial anatomy associated with unicoronal synostosis.

Method

CT scans of 33 patients with nonsyndromic unicoronal synostosis were included. Proposed mid-sagittal plane was compared with commonly used sagittal planes: (1) nasion, sella, and basion (N-S-BA); (2) midplane of bilateral frontozygomatic sutures (midFZ); and (3) the skull gravity center plane, to evaluate reliability and validity in the assessments of the anterior and posterior skull base.

Results

The proposed midplane is similar to the midFZ plane in describing the direction of the anterior skull base. However, it has less bias than the N-S-BA (P < 0.001), and the gravity center planes (P < 0.001). The proposed midplane measures the direction of the posterior skull base plane, similar to the midFZ and gravity center planes, but it has less measurement deviation than the N-S-BA plane (P < 0.001). The most protrusive point on the frontal bone in unicoronal patients is contralateral to the fused suture and distant from the mid-sagittal plane by 13.93 ± 4.01 mm. In addition, it is more anteriorly positioned, by 5.32 mm (P < 0.001), when compared with the corresponding point on the synostotic side. The uppermost point of the supraorbital rim on the synostotic side is cephalic to that of the contralateral side by 4.09 mm (P < 0.001).

Conclusions

Prioritized orientation of an averaged Frankfort horizontal plane, followed by the location of the mid-sagittal and coronal planes, can generate a reliable and valid coordinate framework for the assessment of asymmetric skull shape in unicoronal synostosis.

Three-dimensional printing and craniosynostosis surgery

OVERVIEW

The goal of this study was to review the current application and status of three-dimensional printing for craniosynostosis surgery.

METHODS

A literature review was performed using the PubMed/MEDLINE databases for studies published between 2010 and 2020. All studies demonstrating the utilization of three-dimensional printing for craniosynostosis surgery were included.

RESULTS

A total of 15 studies were ultimately selected. This includes studies demonstrating novel three-dimensional simulation and printing workflows, studies utilizing three-dimensional printing for surgical simulation, as well as case reports describing prior experiences.

CONCLUSION

The incorporation of three-dimensional printing into the domain of craniosynostosis surgery has many potential benefits. This includes streamlining surgical planning, developing patient-specific template guides, enhancing residency training, as well as aiding in patient counseling. However, the current state of the literature remains in the validation stage. Further study with larger case series, direct comparisons with control groups, and prolonged follow-up times is necessary before more widespread implementation is justified.

Distraction osteogenesis in craniosynostosis

PURPOSE OF REVIEW

Craniosynostosis, a condition of premature cranial suture fusion, can have significantly detrimental effects on development and growth due to sequelae of increased intracranial hypertension (ICP), exophthalmos, and upper airway obstruction. Evolving surgical treatments now include distraction osteogenesis (DO) due to its many benefits relative to standard cranial vault remodeling procedures. This article provides an overview and update of different surgical applications of DO for patients with craniosynostosis.

RECENT FINDINGS

DO has been utilized successfully for single and multisuture craniosynostosis with or without midface hypoplasia to increase intracranial volume, decrease ICP and improve aesthetics. It has been applied in single suture synostosis, posterior vault DO, fronto-orbital advancement, monobloc DO and Le Fort III DO. DO has been applied through modification of traditional surgical procedures with success in maintaining goals of surgery while reducing risk.

SUMMARY

DO is still a relatively new and evolving surgical technique for patients with syndromic and nonsyndromic craniosynostosis. With promising benefits, consideration for each procedure should be weighed until longer-term data is available.

[Skull defect repair in children using a 3D-printing technology]

Currently, 3D-printing technologies are increasingly used in neurosurgery. Active development of this approach is valuable to improve preoperative planning, intraoperative navigation, and manufacturing of realistic training models. In this manuscript, the authors report an experience of the pediatric neurosurgical department of the Almazov National Medical Research Center regarding 3D-printing technologies in manufacturing of individual implants for skull defect closure. The main aspects of this technology, advantages and disadvantages are considered. Moreover, the authors describe several cases of creating individual implants for children with skull defects of various origins, dimensions and complexity.

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.

Present and future for technologies to develop patient-specific medical devices: a systematic review approach

The main purpose of this investigation was to systematically review the literature regarding case studies on patient-specific implants and devices, with the goal of analyzing the process of developing custom-made medical devices. A content analysis was performed to identify design processes and methodologies implemented to develop devices such as implants adapted to bone geometries. Reverse engineering, computer-aided design, simulation of assets, and rapid prototyping technologies were selected according to their interoperability in a process framework for developing new products. Finally, results from the case studies and process stages identified in the consulted research were analyzed. These results showed a relationship between the scope and complexity of the process and the stage of technology integration of the patient-specific device development. The analyzed case studies were characterized by technical, scientific, and multidisciplinary components to achieve research goals. Likewise, integration of technologies using patient-specific technologies is needed for product development that converges into designing devices, such as implants, biomodels, and cutting drilling guides.