A new three-dimensional measurement in evaluating the cranial asymmetry caused by craniosynostosis

Application of Virtual Planning and 3-Dimensional Printing Guide in Surgical Management of Craniosynostosis

OBJECTIVE

This study aims to elaborate on the application of virtual surgical planning (VSP) and 3-dimensional printing (3DP) guides in the surgical management of craniosynostosis and compare their surgical outcomes with traditional surgical planning.

METHODS

A retrospective review of patients who underwent cranial vault and cranio-orbital remodeling procedures for craniosynostosis was performed. VSP was accomplished by establishing a 3D model from Digital Imaging and Communications in Medicine format computed tomography data. Patients' skull shapes were adjusted according to the age-matched standard skull; cutting and reconstruction guides were printed using a 3D printer. The change of anthropometric cranial indices, the so-called degree of correction, before and after the operation was evaluated to assess the surgical outcome. The traditional surgical planning group serves as the historical control group, and surgical outcomes were compared among propensity-matched patients in the VSP + 3DP group.

RESULTS

In total, 120 patients with various presentations of craniosynostosis were operated on from 2005 to 2024, and 77 received surgery with VSP + 3DP. There were 35 matched pairs. Both had 17 male patients with similar age and body weight. A greater degree of correction was achieved in the VSP + 3DP group (9.75% vs. 6.36%, P value = 0.016) with less intraoperative blood loss (144.57 mL vs. 296.86 mL, P value < 0.001), shorter operation time (335.23 minutes vs. 348.34 minutes, P value = 0.501), and hospital stay (10.31 days vs. 12.63 days, P value = 0.009).

CONCLUSIONS

With VSP and 3DP guides, precise preoperative planning, efficient intra-operative correction of cranial deformity, and objective surgical outcome assessment are achieved in craniosynostosis operations.

Creating high-resolution 3D cranial implant geometry using deep learning techniques

Creating a personalized implant for cranioplasty can be costly and aesthetically challenging, particularly for comminuted fractures that affect a wide area. Despite significant advances in deep learning techniques for 2D image completion, generating a 3D shape inpainting remains challenging due to the higher dimensionality and computational demands for 3D skull models. Here, we present a practical deep-learning approach to generate implant geometry from defective 3D skull models created from CT scans. Our proposed 3D reconstruction system comprises two neural networks that produce high-quality implant models suitable for clinical use while reducing training time. The first network repairs low-resolution defective models, while the second network enhances the volumetric resolution of the repaired model. We have tested our method in simulations and real-life surgical practices, producing implants that fit naturally and precisely match defect boundaries, particularly for skull defects above the Frankfort horizontal plane.

Patient-Specific Three-Dimensional Printing Guide for Single-Stage Skull Bone Tumor Surgery: Novel Software Workflow with Manufacturing of Prefabricated Jigs for Bone Resection and Reconstruction

OBJECTIVE

To describe a novel system workflow to design and manufacture patient-specific three-dimensional (3D) printing jigs for single-stage skull bone tumor excision and reconstruction and to present surgical outcomes of 14 patients.

METHODS

A specific computer-aided design/computer-aided manufacturing software and hardware system was set up, including a virtual surgical planning subsystem and a 3D printing-associated manufacturing subsystem. Computed tomography data of the patient's skull were used for 3D rendering of the skull and tumor. The output of patient-specific designing included a 3D printing guide for tumor resection and a 3D printing model of the bone defect after tumor excision. A polymethyl methacrylate implant was fabricated preoperatively and used for repair.

RESULTS

The specific 3D printing guide was used to design intraoperative jigs and implants for 14 patients (age range, 1-72 years) with skull bone tumors. In all cases, the cutting jig allowed precise excision of tumor and bone, and implants were exact fits for the defects created. All operative results were successful, without intraoperative or postoperative complications. Postoperative computed tomography scans were obtained for analysis. Postoperative 3D measurement of the skull symmetry index (cranial vault asymmetry index) showed significant improvement of head contour after surgery.

CONCLUSIONS

The computer-aided design/computer-aided manufacturing system described allows definitive preoperative planning and fabrication for treatment of skull bone tumors. Apparent benefits of the method include more accurate determination of surgical margins and better oncological outcomes.

Application of 3D Printed Models of Complex Hypertrophic Scars for Preoperative Evaluation and Surgical Planning

Background

Complex hypertrophic scar is a condition that causes multiple joint contractures and deformities after trauma or burn injuries. Three-dimensional (3D) printing technology provides a new evaluation method for this condition. The objective of this study was to print individualized 3D models of complex hypertrophic scars and to assess the accuracy of these models.

Methods

Twelve patients with complex hypertrophic scars were included in this study. Before surgery, each patient underwent a computed tomography (CT) scan to obtain cross-sectional information for 3D printing. Mimics software was used to process the CT data and create 3D printed models. The length, width, height, and volume measurements of the physical scars and 3D printed models were compared. Experienced surgeons used the 3D models to plan the operation and simulate the surgical procedure. The hypertrophic scar was completely removed for each patient and covered with skin autografts. The surgical time, bleeding, complications, and skin autograft take rate were recorded. All patients were followed up at 12 months. The surgeons, young doctors, medical students, and patients involved in the study completed questionnaires to assess the use of the 3D printed models.

Results

The 3D models of the hypertrophic scars were printed successfully. The length, width, height, and volume measurements were significantly smaller for the 3D printed models than for the physical hypertrophic scars. Based on preoperative simulations with the 3D printed models, the surgeries were performed successfully and each hypertrophic scar was completely removed. The surgery time was shortened and the bleeding was decreased. On postoperative day 7, there were two cases of subcutaneous hemorrhage, one case of infection and one case of necrosis. On postoperative day 12, the average take rate of the skin autografts was 97.75%. At the 12-month follow-up, all patients were satisfied with the appearance and function.

Conclusion

Accurate 3D printed models can help surgeons plan and perform successful operations, help young doctors and medical students learn surgical methods, and enhance patient comprehension and confidence in their surgeons.

[The development and recent status of the craniomaxillofacial surgery in China during past three decades]

The authors made a profound review on the development and the recent status of craniomaxillofacial surgery in China during past three decades. The emphases were placed on the following aspects: the modifications of the reconstructive procedure and minimal invasive mode, the researches on molecular genetic characteristics of the congenital craniofacial malformations, the clinical applications of three-dimensional digital computer-aided techniques (including three-dimensional printing and prefabricated template for precious osteotomies), the craniomaxillofacial defects reconstructing by using the distraction osteogenesis and osseous integrated titanium implant and prothesis, etc. Finally, the authors outlooked prospectively the future trends of the craniomaxillofacial surgery.

3D morphological change of skull base and fronto-temporal soft-tissue in the patients with unicoronal craniosynostosis after fronto-orbital advancement

PURPOSE

This study aims to comprehensively evaluate the deformation of the skull base and fronto-temporal soft tissue in the patients with anterior plagiocephaly over 1 year of age by three-dimensional (3D) imaging after fronto-orbital advancement (FOA).

METHODS

We quantitatively analyzed the surgical results and outcome of FOA performed in 10 patients with anterior plagiocephaly. The measurements of the skull base and fronto-temporal soft tissue were performed based on 3D computed tomography (CT) scan. We assessed symmetry of the skull base and fronto-temporal soft tissue change.

RESULTS

The mean age of patients at FOA was 38.9 months. A significant asymmetry of the skull base was found in all the patients. The growth of the anterior and middle fossae was restricted and the deformation of the fronto-temporal region was marked by soft tissue measurements in different grades. On the follow-up CT images 23.6 months after surgery, there was prominent change (p < 0.05) between the two hemibases (CSO^ ratio) and between the lengths and angles of the anterior and middle cranial hemi-fossae (CX, CSX^, XSM^, XM ratio), especially in grade IIA. Anterior cranial vault asymmetry index obviously decreased to - 1.2 from 12% after surgery (p < 0.05). What's more, ACA^ was also proved to be less after surgical correction (19.91° versus 8.29°, p < 0.01) in grade IIA. The change of fronto-temporal soft tissue was significant such as the frontal angle, the angle of the frontal plane, the fontal-temporal angle, and the angle of the temporal plane in different grades.

CONCLUSIONS

The asymmetry of the skull base and the deformation of the fronto-temporal region can be presented by intracranial view at over 1 year of age in different grades. FOA can correct the skeletal malformation of the fronto-temporal region as well as soft tissue and the asymmetry of the skull base was improved after surgical treatment.