An Overview of 3D Anatomical Model Printing in Orthopedic Trauma Surgery.

Introduction: 3D object printing technology is a resource increasingly used in medicine in recent years, mainly incorporated in surgical areas like orthopedics. The models made by 3D printing technology provide surgeons with an accurate analysis of complex anatomical structures, allowing the planning, training, and surgery simulation. In orthopedic surgery, this technique is especially applied in oncological surgeries, bone, and joint reconstructions, and orthopedic trauma surgeries. In these cases, it is possible to prototype anatomical models for surgical planning, simulating, and training, besides printing of instruments and implants. Purpose: The purpose of this paper is to describe the acquisition and processing from computed tomography images for 3D printing, to describe modeling and the 3D printing process of the biomodels in real size. This paper highlights 3D printing with the applicability of the 3D biomodels in orthopedic surgeries and shows some examples of surgical planning in orthopedic trauma surgery. Patients and Methods: Four examples were selected to demonstrate the workflow and rationale throughout the process of planning and printing 3D models to be used in a variety of situations in orthopedic trauma surgeries. In all cases, the use of 3D modeling has impacted and improved the final treatment strategy. Conclusion: The use of the virtual anatomical model and the 3D printed anatomical model with the additive manufacturing technology proved to be effective and useful in planning and performing the surgical treatment of complex articular fractures, allowing surgical planning both virtual and with the 3D printed anatomical model, besides being useful during the surgical time as a navigation instrument.

Investigation of the Use of Hollow Elastic Biomodels Produced by Additive Manufacturing for Clip Choice and Surgical Simulation in Microsurgery for Intracranial Aneurysms.

BACKGROUND: Intracranial aneurysms (IAs) are dilatations of the cerebral arteries, whose treatment is commonly based on the implant of a metallic clip on the aneurysm neck. Despite the dissection and understanding of the surgical anatomy of the IA when often only parts of it are visible, the choice of the ideal clip to be used is one of the surgical difficulties. Although current imaging tests guarantee IA visualization, currently there is no planning method that allows for a real three-dimensional (3D) visualization for optimal choice of clip prior to surgery. The aim of this study is to evaluate whether IA biomodels generated by additive manufacturing methods are useful for surgical clip selection in microsurgeries for IA. METHODS: Three-dimensional (3D) IA biomodels of 10 patients with IA were evaluated using computerized tomography, surgical microscope, and 3D printer. The research was divided into 4 phases as follows: development of the 3D biomodels, evaluation of the biomodel dimensional characteristics, surgical planning evaluation with the biomodel and its clipping effectiveness, and evaluation of the actual surgical simulation process within the models. RESULTS: Ten 3D biomodels were obtained, made of a malleable and hollow part, formed by the IA and related arteries, and another rigid part, mimicking the skull and other arteries of the skull base. Based on these 3D models, 10 clips were chosen during the surgical planning, and all exactly matched the clip characteristics used during the actual surgeries. The surgical simulation with the biomodels performed by 2 neurosurgeons still in training obtained 100% accuracy in the identification of the clips that were eventually used during the actual surgeries. CONCLUSIONS: 3D biomodels generated by additive manufacturing methods were effective for surgical clip selection in microsurgeries for IA, reducing surgical time, increasing cerebral angioarchitecture understanding, and providing more safety in this type of surgery.

Determining the Accuracy of the Mandibular Canal Region in 3D Biomodels Fabricated from CBCT Scanned Data: A Cadaveric Study.

OBJECTIVE: To validate the accuracy of the mandibular canal region in 3D biomodel produced by using data obtained from Cone-Beam Computed Tomography (CBCT) of cadaveric mandibles. METHODS: Six hemi-mandible samples were scanned using the i-CAT CBCT system. The scanned data was transferred to the OsiriX software for measurement protocol and subsequently into Mimics software to fabricate customized cutting jigs and 3D biomodels based on rapid prototyping technology. The hemi-mandibles were segmented into 5 dentoalveolar blocks using the customized jigs. Digital calliper was used to measure six distances surrounding the mandibular canal on each section. The same distances were measured on the corresponding cross-sectional OsiriX images and the 3D biomodels of each dentoalveolar block. RESULTS: Statistically no significant difference was found when measurements from OsiriX images and 3D biomodels were compared to the "gold standard" -direct digital calliper measurement of the cadaveric dentoalveolar blocks. Moreover, the mean value difference of the various measurements between the different study components was also minimal. CONCLUSION: Various distances surrounding the mandibular canal from 3D biomodels produced from the CBCT scanned data was similar to that of direct digital calliper measurements of the cadaveric specimens.

Teaching facial fracture repair: A novel method of surgical skills training using three-dimensional biomodels.

BACKGROUND: The facial fracture biomodel is a three-dimensional physical prototype of an actual facial fracture. The biomodel can be used as a novel teaching tool to facilitate technical skills training in fracture reduction and fixation, but more importantly, can help develop diagnostic and management competence. OBJECTIVE: To introduce the 'facial fracture biomodel' as a teaching aid, and to provide preliminary evidence of its effectiveness in teaching residents the principles of panfacial fracture repair. METHODS: Computer three-dimensional image processing and rapid prototyping were used to generate an accurate physical model of a panfacial fracture, mounted in a silicon 'soft tissue' base. Senior plastic surgery residents in their third, fourth and fifth years of training across Canada were invited to participate in a workshop using this biomodel to simulate panfacial fracture repair. A short didactic presentation outlining the 'patient's' clinical and radiological findings, and key principles of fracture repair, was given by a consultant plastic surgeon before the exercise. The residents completed a pre- and postbiomodel questionnaire soliciting information regarding background, diagnosis and management, and feedback. RESULTS: A total of 29 residents completed both pre- and postbiomodel questionnaires. Statistically significant results were found in the following areas: diagnosis of all fracture patterns (P=8.2×10(-7) [t test]), choice of incisions for adequate exposure (P=0.04 [t test]) and identifying sequence of repair (P=0.019 [χ(2) test]). Subjective evaluation of workshop effectiveness revealed a statistically significant increase in 'comfort level' only among third year trainees. Overall, positive feedback was reported among all participants. CONCLUSIONS: Biomodelling is a promising ancillary teaching aid that can assist in teaching residents technical skills, as well as how to assess and plan surgical repair.

HISTORIQUE: Le biomodèle de fracture au visage est un prototype physique tridimensionnel de véritable fracture au visage. Il peut être utilisé comme outil d'enseignement novateur pour faciliter l'enseignement des habiletés techniques afin de réduire et fixer les fractures, mais surtout, pour acquérir des compétences de diagnostic et de prise en charge. OBJECTIF: Présenter le « biomodèle de fracture au visage ¼ comme aide à l'enseignement et fournir des données préliminaires de son efficacité à enseigner aux résidents les principes de la réparation des fractures panfaciales. MÉTHODOLOGIE: Le traitement informatique d'images tridimensionnelles et le prototypage rapide ont été utilisés pour générer un modèle physique précis de fracture panfaciale, monté sur une base de « tissus mous ¼ de silicone. Les résidents seniors en chirurgie plastique de troisième, quatrième et cinquième années du Canada ont été invités à participer à un atelier au moyen de ce biomodèle pour simuler la réparation d'une fracture panfaciale. Avant l'exercice, un plasticien consultant a fait une courte présentation didactique soulignant les observations cliniques et radiologiques du « patient ¼ et les principaux principes de la réparation de la fracture. Les résidents ont rempli un questionnaire avant et après avoir utilisé le biomodèle, contenant leurs commentaires et de l'information sur l'expérience, le diagnostic et la prise en charge. RÉSULTATS: Au total, 29 résidents ont rempli le questionnaire avant et après le biomodèle. Des résultats statistiquement significatifs ont été constatés dans les secteurs suivants : diagnostic de tous les profils de fracture (P=8,2×10−7 [test t]), choix d'incisions pour une exposition adéquate (P=0,04 [test t]) et détermination de la séquence de réparation (P=0,019 [test χ2]). D'après l'évaluation subjective de l'efficacité de l'atelier, seuls les résidents de troisième année présentaient une augmentation statistiquement significative du « niveau de confort ¼. Dans l'ensemble, tous les participants ont fait des commentaires positifs. CONCLUSIONS: Le biomodélisation est une aide auxiliaire à l'enseignement prometteuse qui peut contribuer à enseigner aux résidents les habiletés techniques, de même que l'évaluation et la planification des réparations chirurgicales.