Use of the 3D surgical modelling technique with open-source software for mandibular fibula free flap reconstruction and its surgical guides

Barriers of Three-Dimensional Printing in Craniofacial Plastic Surgery Practice: A Pilot Study and Literature Review

OBJECTIVE

Three-dimensional printing (3Dp) and modeling have demonstrated increasing utility within plastic and reconstructive surgery (PRS). This study aims to understand the prevalence of how this technology is utilized in craniofacial surgery, as well as identify barriers that may limit its integration into practice.

METHODS

A survey was developed to assess participant demographics, characteristics of 3Dp use, and barriers to utilizing three-dimensional technologies in practice. The survey was distributed to practicing craniofacial surgeons. A secondary literature review was conducted to identify solutions for barriers and potential areas for innovation.

RESULTS

Fifteen complete responses (9.7% response rate) were analyzed. The majority (73%) reported using three-dimensional modeling and printing in their practice, primarily for surgical planning. The majority (64%) relied exclusively on outside facilities to print the models, selecting resources required to train self and staff (55%), followed by the cost of staff to run the printer (36%), as the most common barriers affecting 3Dp use in their practice. Of those that did not use 3Dp, the most common barrier was lack of exposure (75%). The literature review revealed cost-lowering techniques with materials, comparability of desktop commercial printers to industrial printers, and incorporation of open-source software.

CONCLUSIONS

The main barrier to integrating 3Dp in craniofacial plastic and reconstructive surgery practice is the perceived cost associated with utilizing the technology. Ongoing literature highlights the cost-utility of in-house 3Dp technologies and practical cost-saving methods. The authors' results underscore the need for broad exposure for currently practicing attendings and trainees in 3Dp practices and other evolving technologies.

Three-dimensional analysis of reconstructed skulls using three different open-source software versus commercial software

This study aimed to compare the 3D skull models reconstructed from computed tomography (CT) images using three different open-source software with a commercial software as a reference. The commercial Mimics v17.0 software was used to reconstruct the 3D skull models from 58 subjects. Next, two open-source software, MITK Workbench 2016.11, 3D Slicer 4.8.1 and InVesalius 3.1 were used to reconstruct the 3D skull models from the same subjects. All four software went through similar steps in 3D reconstruction process. The 3D skull models from the commercial and open-source software were exported in standard tessellation language (STL) format into CloudCompare v2.8 software and superimposed for geometric analyses. Hausdorff distance (HD) analysis demonstrated the average points distance of Mimics versus MITK was 0.25 mm. Meanwhile, for Mimics versus 3D Slicer and Mimics versus InVesalius, there was almost no differences between the two superimposed 3D skull models with average points distance of 0.01 mm. Based on Dice similarity coefficient (DSC) analysis, the similarity between Mimics versus MITK, Mimics versus 3D Slicer and Mimics versus InVesalius were 94.1, 98.8 and 98.3%, respectively. In conclusion, this study confirmed that the alternative open-source software, MITK, 3D Slicer and InVesalius gave comparable results in 3D reconstruction of skull models compared to the commercial gold standard Mimics software. This open-source software could possibly be used for pre-operative planning in cranio-maxillofacial cases and for patient management in the hospitals or institutions with limited budget.

Realizing in-house algorithm-driven free fibula flap set up within 24 hours: a pilot study evaluating accuracy with open-source tools

Objective

This study aims to critically evaluate the effectiveness and accuracy of a time safing and cost-efficient open-source algorithm for in-house planning of mandibular reconstructions using the free osteocutaneous fibula graft. The evaluation focuses on quantifying anatomical accuracy and assessing the impact on ischemia time.

Methods

A pilot study was conducted, including patients who underwent in-house planned computer-aided design and manufacturing (CAD/CAM) of free fibula flaps between 2021 and 2023. Out of all patient cases, we included all with postoperative 3D imaging in the study. The study utilized open-source software tools for the planning step, and three-dimensional (3D) printing techniques. The Hausdorff distance and Dice coefficient metrics were used to evaluate the accuracy of the planning procedure.

Results

The study assessed eight patients (five males and three females, mean age 61.75 ± 3.69 years) with different diagnoses such as osteoradionecrosis and oral squamous cell carcinoma. The average ischemia time was 68.38 ± 27.95 min. For the evaluation of preoperative planning vs. the postoperative outcome, the mean Hausdorff Distance was 1.22 ± 0.40. The Dice Coefficients yielded a mean of 0.77 ± 0.07, suggesting a satisfactory concordance between the planned and postoperative states. Dice Coefficient and Hausdorff Distance revealed significant correlations with ischemia time (Spearman's rho = -0.810, p = 0.015 and Spearman's rho = 0.762, p = 0.028, respectively). Linear regression models adjusting for disease type further substantiated these findings.

Conclusions

The in-house planning algorithm not only achieved high anatomical accuracy, as reflected by the Dice Coefficients and Hausdorff Distance metrics, but this accuracy also exhibited a significant correlation with reduced ischemia time. This underlines the critical role of meticulous planning in surgical outcomes. Additionally, the algorithm's open-source nature renders it cost-efficient, easy to learn, and broadly applicable, offering promising avenues for enhancing both healthcare affordability and accessibility.

Use of Preoperative 3D Virtual Planning and 3D-Printed Patient-Specific Guides to Facilitate a Single-Stage Cranial Closing Wedge Ostectomy and Tibial Plateau Leveling Osteotomy Procedure to Address Proximal Tibial Deformity, an Excessive Tibial Plateau Angle, and Cranial Cruciate Ligament Insufficiency in a Dog

A 9-month-old mixed-breed dog was presented for bilateral proximal tibial deformity resulting in an excessive tibial plateau angle and cranial cruciate ligament insufficiency. Initial surgical management of the right pelvic limb was done by performing a cranial closing wedge ostectomy. Inadequate leveling of the plateau resulted in a postliminal meniscal tear which was addressed during a revision tibial plateau leveling osteotomy. The left pelvic limb was managed in a single-session surgery using three-dimensional (3D) virtual surgical planning and custom 3D-printed surgical guides to perform a combined cranial closing wedge ostectomy and tibial plateau leveling osteotomy. Postoperative 3D analysis of the left tibia revealed the accuracy of the surgical result within 2° of the virtual surgical plan. The dog developed a transient grade II/IV left medial patellar luxation following surgery but ultimately attained a full functional recovery and was actively engaged in competitive agility work 46 months following surgery on the left pelvic limb.

Domain adaptive Sim-to-Real segmentation of oropharyngeal organs

Video-assisted transoral tracheal intubation (TI) necessitates using an endoscope that helps the physician insert a tracheal tube into the glottis instead of the esophagus. The growing trend of robotic-assisted TI would require a medical robot to distinguish anatomical features like an experienced physician which can be imitated by utilizing supervised deep-learning techniques. However, the real datasets of oropharyngeal organs are often inaccessible due to limited open-source data and patient privacy. In this work, we propose a domain adaptive Sim-to-Real framework called IoU-Ranking Blend-ArtFlow (IRB-AF) for image segmentation of oropharyngeal organs. The framework includes an image blending strategy called IoU-Ranking Blend (IRB) and style-transfer method ArtFlow. Here, IRB alleviates the problem of poor segmentation performance caused by significant datasets domain differences, while ArtFlow is introduced to reduce the discrepancies between datasets further. A virtual oropharynx image dataset generated by the SOFA framework is used as the learning subject for semantic segmentation to deal with the limited availability of actual endoscopic images. We adapted IRB-AF with the state-of-the-art domain adaptive segmentation models. The results demonstrate the superior performance of our approach in further improving the segmentation accuracy and training stability.

Point-of-Care Virtual Surgical Planning and 3D Printing in Oral and Cranio-Maxillofacial Surgery: A Narrative Review

This paper provides an overview on the use of virtual surgical planning (VSP) and point-of-care 3D printing (POC 3DP) in oral and cranio-maxillofacial (CMF) surgery based on a literature review. The authors searched PubMed, Web of Science, and Embase to find papers published between January 2015 and February 2022 in English, which describe human applications of POC 3DP in CMF surgery, resulting in 63 articles being included. The main review findings were as follows: most used clinical applications were anatomical models and cutting guides; production took place in-house or as "in-house-outsourced" workflows; the surgeon alone was involved in POC 3DP in 36 papers; the use of free versus paid planning software was balanced (50.72% vs. 49.27%); average planning time was 4.44 h; overall operating time decreased and outcomes were favorable, though evidence-based studies were limited; and finally, the heterogenous cost reports made a comprehensive financial analysis difficult. Overall, the development of in-house 3D printed devices supports CMF surgery, and encouraging results indicate that the technology has matured considerably.

Low-Cost and Simple Frontal Sinus Surgical Cutting Guide Modeling for Anterior Cranioplasty in Facial Feminization Surgery: How To Do It

BACKGROUND

This study demonstrates a novel and simple design to create a low cost frontal sinus surgical cutting guide, using patient's frontal sinus cavities as references, to perform an anterior cranioplasty in facial feminization surgery. A clinical series demonstrates its clinical use and safety.

MATERIAL AND METHODS

Authors used a 4 open-source software protocol for the virtual surgical modeling (VSP). Retrospectively, pre- and post-operative complications were reviewed, and a FACE-Q questionnaires were used to evaluate patient's postoperative "Satisfaction with forehead and eyebrows." Recordings of the VSP and surgical technic are presented.

RESULTS

Sixteen patients were operated between November 2018 and November 2020 using in-house surgical guides. All were performed by authors in 5 to 10 minutes using Blender open-source Software. No complications were reported and authors always found an optimal retention of the surgical guide on the convex bony surface of the forehead and frontonasal area. FACE-Q questionnaire reported a very high satisfaction for all patients (mean score: 22/24).

DISCUSSION

This simplify organic design can be performed efficiently by any surgeon even without previous training in home staging VSP. Patient satisfaction was very high, along with an absence of postoperative complications.

Improved technique of personalised surgical guides generation for mandibular free flap reconstruction using an open-source tool

With advancements in computer systems, computer graphics and medical imaging technologies, clinicians strive for a personalised approach to patient treatment. Therefore, the production of personalised surgical guides is becoming standard. While proprietary software solutions for mandibular reconstruction planning exist, they are often not available due to their high costs. There are multiple alternative methods available, which utilise open-source technologies and free software, but they use advanced three-dimensional (3D) computer-aided design (CAD) concepts. The goal of this article is to provide end-users (surgeons, radiologists, or radiology technicians) with a tool that offers an intuitive interface and a simple workflow. The tool provides only the necessary methods offering a high degree of automation and abstracting the underlying 3D CAD concepts. This is accomplished by providing an add-on (written in Python) for a free and open-source software package Blender.

Rapid prototyping: applications in oral and maxillofacial surgery

This article documents four mandibular reconstructions performed using free fibula flaps. CT scan DICOM (Digital Imaging and COmmunication in Medicine) files were obtained in order to print stereolithographic models of the mandible, and in one case cutting guides for fibular osteotomies. One case study details the treatment a cancer recurrence on a right emimandibulectomy. Because of a lack of access to previous CT scans, the left part of the mandible was mirrored to obtain an accurate 3D model. In one case, due to the young age of the woman, a double barrel fibula flap was used. All cases resulted in satisfactory chewing function and aesthetic outcome, with no flap failures. The report concludes that Virtual Planning and Rapid Prototyping are helpful as they reduce costs and intraoperative times while simultaneously improving surgical precision.

Computer-Aided Surgical Simulation in Severe Atrophic Mandibular Fractures: A New Method for Guided Reduction and Temporary Stabilization Before Fixation

In severe atrophic mandibular fractures, the absence of stable occlusion, as well as poor bone volume at the fracture site, constitutes a lack of references during surgery to achieve accurate fracture reduction. Unsuccessful reduction and stabilization can lead to several complications, such as fracture misalignments, malunion, and facial asymmetry. An alternative to avoid the aforementioned issues is fracture reduction based on virtual surgical planning (VSP) technology. However, there is little information regarding VSP protocols for the management of mandible fractures. Herein, a new technique with low cost is reported in which VSP and computer-aided manufacturing of a positioning guide were applied in a 72-year-old female patient with bilateral fractures in her atrophic mandible in the body region. The positioning guide was used during fracture reduction on the inferior surface of the mandible as per the virtual reduction. A 3-dimensional mandible model was also printed, facilitating the prebent 2.4-mm reconstructive plate. The surgical procedure was performed with no complications, resulting in the accurate fit of both the bent plate and the guide. A postoperative computed tomography scan showed good condylar position, fracture reduction, and hardware adaptation. A follow-up approximately 2 years later showed that she was successfully rehabilitated with the dental prosthesis. Therefore, VSP is a valuable tool for attaining a predictable result in the treatment of severe atrophic mandibular fracture, with a reduced operative duration, acceptable precision of fracture reduction, and low cost.

Dental implant-based oral rehabilitation in patients reconstructed with free fibula flaps: Clinical study with a follow-up 3 to 6 years

BACKGROUND

Oral rehabilitation of patients after maxillofacial reconstructive surgery represents a challenge and stable prosthetic retention can be achieved with the use of dental implants.

PURPOSE

This retrospective report aimed to evaluate implant-based oral rehabilitation following maxillofacial reconstruction with free fibula flaps.

MATERIALS AND METHODS

A total of 14 patients who had reconstruction with fibula flaps either by CAD/CAM or conventional surgery were included in this study. A total of 56 implants (40 in flaps, 16 in native bone) were evaluated. Follow-up after reconstructive surgery ranged between 3.25 and 6.3 years. Follow-up after implant surgery ranged between 1.5 and 3.8 years.

RESULTS

Overall survival rate was 85.7% in free fibula flaps and 85.6% in dental implants. Eight implants were lost in three patients and all of these failures were in dental implants inserted in free flaps. According to the results on patient basis, the implant survival was not influenced by any variable.

CONCLUSIONS

The maxillofacial reconstruction with free fibula flap and oral rehabilitation with implant-supported prostheses after ablative surgery can be considered as an effective and safe procedure with successful aesthetic and functional outcomes.

Surface Replacement Arthroplasty Using a Volar Approach for Osteoarthritis of Proximal Interphalangeal Joint: Results After a Minimum 5-Year Follow-up

Background: Surface replacement arthroplasty (SRA) through a volar approach for the proximal interphalangeal (PIP) joint can preserve the integrity of the extensor tendon, which allows early range of motion (ROM) exercise postoperatively. However, a few reports have shown that the PIP ROM tends to decline with longer follow-up. The goal of this study is to assess the results of at least 5 years of follow-up of SRA through a volar approach and also to investigate the cause of deterioration of ROM with time after SRA through this approach. Methods: Eleven fingers with degenerative osteoarthritis that underwent SRA through the volar approach were examined. ROM of the PIP joint preoperation, 1 year after the surgery, and at final follow-up was measured and statistically analyzed. Also, the relationship between PIP ROM and the osteophyte developed postoperatively was examined. Results: The average follow-up period was 7.3 years. The average PIP ROM of the PIP joints was 52.3° preoperatively, 54.1° at 1 year postoperatively, and 31.1° at the final follow-up. PIP ROM at the final follow-up was significantly decreased compared with that preoperatively or at 1 year postoperatively. Also, the development of an osteophyte was negatively correlated with the ROM of the PIP joint at the final follow-up. Conclusions: PIP ROM after SRA through a volar approach has the tendency to deteriorate with a longer follow-up. Development of an osteophyte is considered to be a main risk factor of deterioration in the cases of SRA through a volar approach.

Should You Buy a Three-Dimensional Printer? A Study of an Orbital Fracture

The use of three-dimensional (3D) printing has been growing significantly in medicine for the past 10 years, especially in maxillofacial surgery. A lot a different softwares and printers are available on the market, and it can be difficult to choose which one fits best one's needs. In the authors' institution, the authors regularly print orbits to prepare the reconstruction. The authors then compared the 3D printing of an orbital fracture between a professional and nonprofessional software and between a bottom of the range and a more elaborated printer. The results show that there is a wide variation between the quality of the printing, as well as the time used for the preparation. Costs between free or professional software must also be considered. In conclusion, an analysis of needs and what is available on the market must be studied before investing in 3D printing.

Virtual Functional Endoscopic Sinus Surgery Simulation with 3D-Printed Models for Mixed-Reality Nasal Endoscopy

The surgeon's knowledge of a patient's individual anatomy is critical in skull base surgery. Trainees and experienced surgeons can benefit from surgical simulation; however, current models are expensive and impractical for widespread use. In this study, we report a next-generation mixed-reality surgical simulator. We segmented critical anatomic structures for 3-dimensional (3D) models to develop a modular teaching tool. We then developed a navigation tracking system utilizing a 3D-printed endoscope as a trackable virtual-reality (VR) controller and validated the accuracy on VR and 3D-printed skull models within 1 cm. We combined VR and augmented-reality visual cues with our 3D physical model to simulate sinus endoscopy and highlight segmented structures in real time. This report provides evidence that a mixed-reality simulator combining VR and 3D-printed models is feasible and may prove useful as an educational tool that is low cost and customizable.

A 3-Dimensional-Printed Short-Segment Template Prototype for Mandibular Fracture Repair

IMPORTANCE

After reduction of complex mandibular fractures, contouring of the fracture plates to fixate the reduced mandibular segments can be time-consuming.

OBJECTIVE

To explore the potential application of a 3-dimensional (3-D)-printed short-segment mandibular template in the management of complex mandibular fractures.

DESIGN, SETTING, AND PARTICIPANTS

A feasibility study was performed at a tertiary academic center using maxillofacial computed tomography data of 3 patients with comminuted mandibular fractures who required preoperative planning with a perfected complete mandible model.

INTERVENTIONS

Thresholding, segmentation, and realignment of the fractured mandible were performed based on computed tomography data. Each reduced mandible design was divided to create 3-D templates for 6 fracture sites: right and left angle, body, and symphyseal/parasymphyseal. Sessions were conducted with junior otolaryngology and plastic surgery residents, during which mandibular fracture plates were contoured in a "preoperative" setting against the 3-D-printed short-segment templates, and an "intraoperative" setting against the previously manufactured, complete mandible model. The previously manufactured, complete model served as a surrogate for the intraoperative mandible with the fracture site reduced.

MAIN OUTCOMES AND MEASURES

The time for 3-D template printing, the "preoperative" (measure of the time consumed preoperatively), and "intraoperative" (measure of the time saved intraoperatively) times were recorded. Comparisons were made for cost estimates between a complete model and the 3-D-printed short-segment template. The operating room charge equivalent of the intraoperative time was also calculated.

RESULTS

Of the 3 patients whose data were used, 1 was a teenager and 2 were young adults. The total time for 3-D modeling and printing per short-segment template was less than 3 hours. The median (range) intraoperative time saved by precontouring the fracture plates was 7 (1-14), 5 (1-30), and 7 (2-15) minutes, and the operating room charge equivalents were $350.35 ($50.05-$700.70), $250 ($50.05-$1501.50), and $350.35 ($100.10-$750.75) for the angle, body, and symphyseal/parasymphyseal segments, respectively. The total cost for a single 3-D-printed template was less than $20, while that for a perfected complete model was approximately $2200.

CONCLUSIONS AND RELEVANCE

We demonstrate that patient- and site-specific 3-D-printed short-segment templates can be created within the timeframe required for mandibular fracture repair. These novel 3-D-printed templates also demonstrate cost efficiency in the preoperative planning for complex mandibular fracture management compared with perfected models and facilitate plate contouring in a similar fashion. Estimation of reduced operative room cost and time with the application of these short-segment templates warrants studies in actual patient care.

LEVEL OF EVIDENCE

NA.

Image once, print thrice? Three-dimensional printing of replacement parts

OBJECTIVE

The last 20 years has seen an exponential increase in 3D printing as it pertains to the medical industry and more specifically surgery. Previous reviews in this domain have chosen to focus on applications within a specific field. To our knowledge, none have evaluated the broad applications of patient-specific or digital imaging and communications in medicine (DICOM) derived applications of this technology.

METHODS

We searched PUBMED and CINAHL from April 2012 to April 2017.

RESULTS

261 studies fulfilled the inclusion criteria. Proportions of articles reviewed: DICOM (5%), CT (38%), MRI (20%), Ultrasonography (28%), and Bio-printing (9%).

CONCLUSION

There is level IV evidence to support the use of 3D printing for education, pre-operative planning, simulation and implantation. In order to make this technology widely applicable, it will require automation of DICOM to standard tessellation language to implant. Advances in knowledge: Recent lapses in intellectual property and greater familiarity with rapid prototyping in medicine has set the stage for the next generation of custom implants, simulators and autografts. Radiologists may be able to help establish reimbursable procedural terminology.