Comparative Study with and without the Use of 3D Prototyping of an Unconventional Technique in the Surgical Planning of Revision of Total Hip Arthroplasty / Estudo comparativo com e sem o uso de prototipagem em 3D de uma técnica não convencional no planejamento cirúrgico de revisão de artroplastia total de quadril

Abstract This article presents a comparison between two cases in which there was a need for revision of total hip arthroplasty due to aseptic acetabular failure. We used 3D prototyping in one of the cases to perform an unconventional technique of molding synthesis material before the procedure to evaluate the time saved in the transoperative period in complex cases.

Resumo Este artigo apresenta uma comparação entre dois casos em que havia a necessidade de revisão de artroplastia total de quadril por falha acetabular asséptica. Utilizamos prototipagem em 3D em um dos casos para realizar uma técnica não convencional de moldagem de material de síntese antes do procedimento, com objetivo de avaliar o tempo economizado no transoperatório em casos complexos.

Modelo de impresión 3D para planificación quirúrgica en trasplante hepático con donante vivo adulto-adulto

Gracias a los grandes avances de la tecnología, los últimos diez años, la impresión en tres dimensiones (3D) se ha convertido en una herramienta accesible, útil e innovadora para distintas áreas de la medicina. Entre ellas planificación quirúrgica, creación de implantes y prótesis, educación médica e incluso comunicación médico-paciente. Con respecto a planificación quirúrgica, la impresión 3D cobra especial relevancia en cirugías de alta complejidad. En el caso del trasplante hepático con donante vivo, donde es prioritario garantizar la máxima seguridad para el donante, al mismo tiempo que la mejor calidad del injerto para el receptor, la planificación quirúrgica es mandatoria. En este aspecto, la impresión 3D de un modelo de hígado, anatómicamente comparable al del donante, entrega al cirujano la posibilidad de obtener una imagen más clara, directa y tangible, desde cualquier ángulo del órgano, que una imagen virtual tradicional. De esta forma, el cirujano tiene a su alcance una herramienta adicional para plantear el mejor abordaje quirúrgico, anticipar variaciones anatómicas e incluso, cuando el material de impresión lo permite, practicar el procedimiento. En Clínica Las Condes, el centro de trasplante junto al Centro de Innovación, trabajaron en conjunto en la impresión 3D de dos modelos de hígado, utilizados para la planificación quirúrgica de los primeros dos trasplantes hepáticos con donante vivo adulto-adulto realizados en Latinoamérica, donde la hepatectomía del donante se realizó de manera totalmente laparoscópica. El objetivo de este trabajo es describir el proceso de impresión 3D y analizar las dificultades y beneficios del proceso y sus resultados.

The last ten years, thanks to the great advances in technology, three-dimensional (3D) printing has become an accessible, useful, and innovative tool for different areas of medicine. These include surgical planning, implant and prosthetic creation, medical education, and even doctor-patient communication. Regarding surgical planning, 3D printing takes on special relevance in highly complex surgeries. In the case of living donor liver transplantation where it is a priority to guarantee maximum safety for the donor, as well as the best quality of the graft for the recipient, surgical planning is mandatory. Regarding this, 3D printing of an anatomically comparable liver model of the donor, gives the surgeon the possibility of obtaining a clearer, more direct, and tangible image, from any angle of the organ, than a traditional virtual image. In this manner, the surgeon has an additional tool to plan the best surgical approach, anticipate anatomical variations and even, when the impression material allows it, to practice the procedure. Transplant center of Clinica las Condes, together with Innovation laboratory worked together on the 3D printing process liver models used for surgical planning of the first two liver transplants with an adult-adult laparoscopic living donor. The objective of this work is to describe the 3D printing process and analyze the difficulties and benefits of the process and its results.

Merits of multicolor imaging for tractional retinal detachment

Purpose: To compare multicolor imaging (MCI) with Optos color fundus photography (OCFP) for the evaluation of morphology and extent of preretinal membranes in diabetic tractional retinal detachments (TRD). Methods: In this retrospective study, 30 eyes with diabetic TRDs were imaged using the MCI feature of the Heidelberg Spectralis Spectral?domain optical coherence tomography (SD?OCT) and color photo using the Optos Daytona ultra?widefield fundus camera. Two investigators independently graded and determined the agreeability between the two modalities with respect to the extent of the TRD and preretinal membranes on the SD?OCT B?scan images. Results: The MCI provided better visualization of the attachments and traction points of the posterior hyaloid face and preretinal membranes and is comparable to the SD?OCT B?scan images. The inter?rater agreeability rates for OCFP had a Kappa (?) value of 0.37, while the MCI had a ? value of 0.46. When comparing between images of different wavelengths, grading using infrared reflectance (IR) had a poor agreement (?0.04 ± 0.04) while green reflectance (GR) (0.46 ± 0.32) and blue reflectance (BR) (0.53 ± 0.19) had a moderate agreement. The composite MCI and GR images also had comparatively higher intraclass coefficient when compared to the OCFP (0.25 [?0.09–0.55]) and IR (?0.03 [?0.39–0.34]) images. Conclusion: MCI is more sensitive for determining the extent of TRDs and for the detection of secondary membranes when compared to OCFP, thus, aiding in better surgical planning.

Application of virtual reality technology in surgical treatment of congenital heart disease complicated with ventricular outflow tract stenosis / 中华胸心血管外科杂志

Objective:To explore the application value of virtual reality(VR) technology in the surgical diagnosis and treatment of congenital heart disease complicated with ventricular outflow tract stenosis.Methods:From November 2017 to October 2018, a total of 11 cases of congenital heart disease complicated with ventricular outflow tract stenosis were diagnosed and treated by VR technology assisted surgery in our center, including 9 cases of tetralogy of Fallot, 1 case of right ventricular double outlet stenosis and 1 case of right ventricular double outlet complicated with right ventricular outflow tract and pulmonary valve stenosis. The matching degree and value score of VR model by surgeons after operation. The data of these cases, including postoperative severe complications, maximum flow velocity and peak pressure difference and left ventricular ejection fraction(LVEF) 3 months after surgery, were retrospectively analyzed to evaluate the application value of VR technology and summarize the application experience of our center.Results:The operations were successful in all the 11 cases with no death in hospital. No serious complications related to the ventricular outflow tract occurred after the operation. The peak systolic velocity of the ventricular outflow tract in all the patients decreased to less than 2 m/s, and LVEF was in the normal range three months after the operation. In terms of VR model scores, the matching degree of all cases was 8/10 or above and 8 patients received a 3/3 of value score.Conclusion:For patients with congenital heart disease complicated with ventricular outflow tract stenosis, VR technology based on CT three-dimensional reconstruction can help surgeons more intuitively understand the spatial location information of each intra- and extra-cardiac structure and evaluate the feasibility of key surgical procedures, which is conducive to individual surgery and guarantees a good surgical outcome.

Virtual surgical planning is a useful tool in the surgical management of mandibular condylar fractures / 中华创伤杂志(英文版)

PURPOSE@#The aim of this study is to evaluate the application value of virtual surgical planning in the management of mandibular condylar fractures and to provide a reliable reference.@*METHODS@#This was a prospective randomized controlled study and recruited 50 patients requiring surgical treatment for their mandibular condylar fractures. The inclusion criteria were patients (1) diagnosed with a condylar fracture by two clinically experienced doctors and required surgical treatment; (2) have given consent for the surgical treatment; and (3) had no contraindications to the surgery. Patients were excluded from this study if: (1) they were diagnosed with a non-dislocated or only slightly dislocated condylar fracture; (2) the comminuted condylar fracture was too severe to be treated with internal reduction and fixation; or (3) patients could not complete follow-up for 3 months. There were 33 male and 17 female patients with 33 unilateral condylar fractures and 17 bilateral condylar fractures included. The 50 patients were randomly (random number) divided into control group (25 patients with 35 sides of condylar fractures) and experimental group (25 patients with 32 sides of condylar fractures). Virtual surgical planning was used in the experimental group, but only clinical experience was used in the control group. The patients were followed up for 1, 3, 6 and 12 months after operation. Variables including the rate of perfect reduction by radiological analysis, the average distance of deviation between preoperative and postoperative CT measurements using Geomagic software and postoperative clinical examinations (e.g., mouth opening, occlusion) were investigated for outcome measurement. SPSS 19 was adopted for data analysis.@*RESULTS@#The average operation time was 180.60 min in the experimental group and 223.2 min in the control group. One week postoperatively, CT images showed that the anatomic reduction rate was 90.63% (29/32) in the experimental group and 68.57% (24/35) in the control group, revealing significant difference (X2 = 4.919, p = 0.027). Geomagic comparative analysis revealed that the average distance of deviation was also much smaller in the experimental group than that in the control group (0.639 mm vs. 0.995 mm; t = 3.824, p < 0.001).@*CONCLUSION@#These findings suggest that virtual surgical planning can assist surgeons in surgical procedures, reduce operative time, and improve the anatomic reduction rate & accuracy, and thus of value in the diagnosis and treatment of condylar fractures.

Efectos de la impresión 3D en la planificación quirúrgica de las cardiopatías congénitas / Impact of 3D printing in surgical planning of congenital heart disease

Resumen Introducción: Los defectos cardíacos congénitos constituyen el 30% de todas las anomalías congénitas. La prevalencia es de 8/1,000 recién nacidos vivos, sin predominio de género. Para una planificación quirúrgica óptima es esencial una evaluación precisa de la anatomía en los defectos cardíacos congénitos. Las modalidades de imagen como el ecocardiograma, la angiografía por cateterismo cardíaco, la tomografía computarizada (TC) o la resonancia magnética (RM) se utilizan de forma regular para el diagnóstico de las cardiopatías congénitas. Estos métodos pueden proporcionar reconstrucciones virtuales en reconstrucción volumétrica o 3D, pero no réplicas táctiles reales de la anatomía cardíaca. Objetivo: Realizar modelos de corazón impresos en 3D con la finalidad de proporcionar réplicas táctiles 3D reales de la anatomía cardíaca para visualizar de forma detallada todas las perspectivas posibles de las estructuras extracardíacas o intracardíacas. Métodos: Los datos de la imagen se obtuvieron en formato DICOM, se editaron en el paquete de software "3D slicer 4.3" y se exportaron para la impresión en formato de archivo (.stl). Resultados y conclusiones: Con la impresión 3D se puede evaluar de forma detallada la anatomía intracardíaca y extracardíaca con modelos cardíacos en tiempo real. Esta técnica es de gran utilidad, sobre todo en los defectos cardíacos congénitos complejos, ya que permite hacer una planificación precisa del procedimiento quirúrgico.

Abstract Introduction: Congenital heart disease makes up for 30% of all congenital anomalies. The prevalence is 8/1,000 live newborns, without predominance of gender. Imaging methods such as echocardiography, angiography, computed tomography or magnetic resonance imaging must be routinely used in congenital heart disease. The mentioned methods can provide virtual reconstructions in volumetric reconstruction or in three dimensional (3D), but only 3D-printed heart models can provide real 3D tactile replicas of cardiac anatomy. Objective: To make 3D printed heart models in order to provide real 3D tactile replicas of the cardiac anatomy that allow a detailed visualization from all possible perspectives, either of extracardiac or intracardiac structures. Methods: This information is useful for surgical decision making, especially in patients with complex cardiac defects. DICOM, edited in a software package "3D slicer 4.3" and exported for printing in file format (.stl). Results and conclusions: With 3D printing, the intracardiac and extracardiac anatomy can be evaluated in detail with real-scale cardiac models of the patient, avoiding unexpected findings. This technique is very useful especially in complex congenital heart defects, since it allows precise planning of the surgical procedure.

3D-printed models improve surgical planning for correction of severe postburn ankle contracture with an external fixator / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Gradual distraction with an external fixator is a widely used treatment for severe postburn ankle contracture (SPAC). However, application of external fixators is complex, and conventional two-dimensional (2D) imaging-based surgical planning is not particularly helpful due to a lack of spatial geometry. The purpose of this study was to evaluate the surgical planning process for this procedure with patient-specific three-dimension-printed models (3DPMs). In this study, patients coming from two centers were divided into two cohorts (3DPM group vs. control group) depending on whether a 3DPM was used for preoperative surgical planning. Operation duration, improvement in metatarsal-tibial angle (MTA), range of motion (ROM), the American Orthopedic Foot and Ankle Society (AOFAS) scores, complications, and patient-reported satisfaction were compared between two groups. The 3DPM group had significantly shorter operation duration than the control group ((2.0±0.3) h vs. (3.2±0.3) h,

Aplicaciones actuales de la impresión cardiaca en 3D / Current applications of cardiac 3D printing

Resumen En esta revisión se abordan las diversas aplicaciones actuales de la impresión tridimensional en enfermedades cardiovasculares, sus limitaciones y dirección a futuro. Se enfatiza en el área de educación, en la cual ha tenido impacto significativo en la experiencia del paciente y del médico, además de beneficios éticos con respecto a la comparación con el uso de cadáveres o modelos animales; también, en el área de planificación quirúrgica donde se optimiza el proceso operatorio y se dan mejoras en los resultados; seguidamente, se explica el área de impresión cardiaca personalizada, que se ha implementado especialmente en casos de anomalías cardiacas congénitas debido a que son muy heterogéneas entre los pacientes y esto permite un estudio individualizado de las mismas con el fin de buscar tratamientos óptimos a mediano y largo plazo. Finalmente se profundiza sobre bioimpresión, la cual constituye el campo con mayor potencial y se ha desarrollado alrededor del reemplazo de estructuras cardiacas como válvulas, investigación de efectos terapéuticos de fármacos y colocación de células con funciones regenerativas. Se concluye lo promisoria que es la impresión cardiaca tridimensional y los múltiples beneficios que puede brindarle a la comunidad médica y a los pacientes.

Abstract For this review the current applications and uses of three-dimensional printing will be studied in cardiovascular diseases, as well as its limitations and future directions. Regarding the education field, it has had a significant impact on the experience of physicians as well as patients, furthermore considering the ethical benefits with regards to the comparison of the use of cadaveric or animal models. Advantages may also be contemplated when discussing surgical planning, where this technology optimizes the surgical process and provides better results. Moreover, patient specific three- dimensional cardiac printing has been applied in cases of congenital heart abnormalities due to its variability among patients, where these models allow for an individual study in search of optimal treatments in the medium and long term. Finally, bioprinting is studied, which constitutes the most promising field, and has developed around the replacement of cardiac structures, such as valves, investigation on therapeutic effects of drugs and cell placement with regenerative functions. In conclusion, the optimistic and favorable future of this technology can be presumed, alongside its multiple benefits that could contribute to the medical community and to the patients.

Localización preoperatoria de la trepanación inicial en el abordaje retrosigmoideo. Revisión de literatura y aplicación quirúrgica / Preoperative location of the initial trepanation in the retrosigmoid approach. Literature review and surgical application

Objetivo: Evaluar una técnica eficaz y reproducible que permita determinar el sitio de la trepanación inicial en el abordaje retrosigmoideo. Materiales y métodos: Se empleó una muestra de 22 pacientes a fin de analizar la relación de la transición transverso ­ sigmoidea (TTS) con el asterion y la ranura digástrica. Todos los casos contaban con TC de cortes finos (1 mm de espesor). Se subdividieron los pacientes en dos grupos. Grupo 1: pacientes con patologías variables, sin alteraciones estructurales en la fosa posterior. Grupo 2: pacientes en los que se realizó un abordaje retrosigmoideo con planificación prequirúrgica del sitio de trepanación inicial. Discusión: Las referencias óseas (asterion y punto digástrico) pudieron identificarse en la totalidad de las TC 3D analizadas. Se analizaron las distancias empleando un sistema de coordenadas. La TTS se registró en el 78% de los casos anterior e inferior al asterion. En ningún caso se encontró la TTS superior al asterion, la ubicación en sentido inferior varió entre 0 mm y 25,5 mm (media 12,5 mm). En el plano anteroposterior, se registró una distancia entre -6,41 mm y 14,5 mm (media 4,09 mm), demostrando una gran variabilidad individual, comparable con lo descripto en la literatura. En el grupo 2, pudo predecirse de manera precisa la localización de la TTS, exponiendo la misma con la trepanación inicial. Conclusión: Se describe un método sencillo, eficaz, de libre acceso, que permite la ubicación del keyhole en el abordaje retrosigmoideo

Objective: To assess an effective and reproducible technique that allows determining the emplacement of the initial burr-hole in the retrosigmoid approach. Materials and methods: A sample of 22 patients was used to analyze the relation among the transverse - sigmoid transition (TTS), the asterion and the digastric groove. All cases had a thin-slice, 1-mm-thick Computed Tomography (CT). Patients were subdivided into two groups. Group 1: patients with variable pathologies, without structural modification of posterior fossa anatomy. Group 2: patients in which a retrosigmoid approach was performed with preoperative surgical planning of the initial burr-hole. Discussion: Bone references (asterion and digastric point) could be identified in the totality of the analyzed 3D CT. The distances were measured using a coordinate system. TTS was recorded in 78% of the cases inferior and anterior to the asterion. In no case the TTS was found superior to the asterion. It was 0 mm to 25.5 mm (mean 12.5 mm) inferior; and a distance between -6.41mm to 14.5mm (mean 4.09mm) in the anteroposterior plane was recorded, demonstrating a large individual variability. In group 2, the location of the TTS could be accurately predicted, exposing it with the initial burr-hole. Conclusion: A simple, effective and access free method is described, which allows the emplacement of the keyhole in the retrosigmoid approach

The Effect of Pelvic Modeling on Outcome in Preoperative Planning for Bernese Acetabular Osteotomy / 医用生物力学

Objective To explore the influence of different model scopes on acetabular stress distribution and optimal osteotomy result in preoperative planning of Bernese acetabular osteotomy. Methods Two patients with hip dysplasia were established according to different model ranges. Model 1 included the affected hip and femur, and Model 2 included the complete pelvis and affected femur. Compare and analyze the acetabular cartilage contact pressure, area and distribution of the two models under single-leg standing conditions, and simulate osteotomy. Results Compared with Model 1 before surgery, Model 2 had higher contact pressure, smaller contact area and closer distribution to the meniscus edge of acetabulum. Compared with 11 postoperative plans, the variation amplitude of contact pressure and the optimal osteotomy angle for Model 1 were all smaller than those of Model 2. Conclusions The preoperative analysis result of the model with affected hip bone and femur would underestimate the degree of stress concentration and misjudge the location of stress concentration, and the obtained optimal osteotomy rotation angle would be relatively small. The research findings provide certain theoretical basis for preoperative planning and modeling of osteotomy.

Efficacy of 3d printing technology-assisted virtual surgical planning in Acetabular fracture fixation / 中国组织工程研究

BACKGROUND: Acetabular fracture is considered to be one of the most challenging fractures because of its complex anatomical structure, which makes it more difficult to treat. At present, open reduction and internal fixation are still the standard treatment methods for displaced acetabular fractures. The patient-specific pre-contour reconstruction template made by three-dimensional (3D) printing technology combined with preoperative virtual surgery plan can reduce the invasiveness of surgery and simplify the operation process. OBJECTIVE: To evaluate the effect of 3D printing combined with virtual surgical planning in the treatment of acetabular fractures compared with traditional reduction and reconstruction of acetabular fractures. METHODS: Totally 25 patients were selected from Affiliated Hospital of Chengde Medical College from October 1, 2017 to March 1, 2018, including 14 males and 11 females, at the age of 21-60 years old. They were divided into experimental group (n=12) and control group (n=13) by computer random grouping method. In the experimental group, printing technology combined with virtual pre-contour reconstruction plate fixation was performed. In the control group, intraoperative contour reconstruction plate fixation was conducted after reduction. Postoperative X-ray and non-contrast CT scan was used to analyze fracture reduction in two groups. After the operation, the patients in the two groups were followed up for visual analogue scale score, Majeed function score and complications. This study was approved by the Ethics Committee of Affiliated Hospital of Chengde Medical College (approval No. LL007). RESULTS AND CONCLUSION: (1) X-ray films showed that the reduction effect of the experimental group was better than that of the control group (P=0.038). Non-contrast CT images showed that the reduction displacement difference of the experimental group was better than that of the control group before and after operation [(12.43±7.58) mm, (9.408±8.27) mm, P < 0.05]. (2) At 6-12 months after surgery, visual analogue scale scores were lower in the experimental group than in the control group [(1,6±0.6), (3.3±1.3), P < 0.05], There were no significant differences in Majeed function scores between the two groups in the final follow-up (P=0.079). (3) Complications, such as delayed healing, failure of internal fixation or deep vein thrombosis, were not found; and no biocompatibility adverse reactions related to the implanted device occurred in the two groups after surgery. (4) Results suggested that 3D printing technology assisted virtual operation plan can improve the reduction quality in the fixation of acetabular fracture, improve the operative effect of acetabular fracture, and reduce the postoperative pain of patients.

Application of 3D visualization and 3D printing in individualized precision surgery for Bismuth-Corlette type Ⅲ and Ⅳ hilar cholangiocarcinoma / 南方医科大学学报

OBJECTIVE@#To explore the application of 3D visualization and 3D printing in individualized precision surgical treatment of Bismuth-Corlette type Ⅲ and Ⅳ hilar cholangiocarcinoma.@*METHODS@#We retrospectively analyzed the data of 10 patients with hilar cholangiocarcinoma undergoing surgeries under the guidance of 3D visualization and 3D printing in the Department of Hepatobiliary Surgery, Zhujiang Hospital from May 2016 to March 2019. Thin-section CT data of the patients were collected for 3D reconstruction and 3D printing, and the 3D printed models were used for observing the 3D relationship of tumor with the intrahepatic bile duct, hepatic artery, portal vein and hepatic vein system and for performing preoperative simulated surgery and surgical planning. The 3D printed models were subsequently used for real-time intraoperative navigation to guide surgeries in the operating room.@*RESULTS@#3D visualization models were successfully reconstructed for all the 10 patients and printed into 3D models. The 3D visualization types in Bismuth-Corlette classification included type Ⅲa (4 cases), type Ⅲb (4 cases), and type Ⅳ (2 cases); 4 patients showed portal vein variation, 3 had hepatic artery variation, and 2 had both portal vein and hepatic artery variations. Two patients were found to have trifurcation type of portal vein variation, one had "I-shaped" variation, and one showed the absence of the right anterior branch of the portal vein; 3 patients had hepatic artery variations with the left hepatic artery originating from the left gastric artery (1 case) and the right hepatic artery originating from the superior mesenteric artery (2 cases). Four patients with type Ⅲb underwent left hepatectomy; 4 with type Ⅲa received right hepatectomy; 1 patient with of type Ⅳ received peripheral hepatic resection and another underwent left hepatectomy. The results of preoperative 3D reconstruction, 3D printed model and preoperative planning were consistent with the intraoperative findings. The operative time was 452±75.12 min with a mean intraoperative blood loss of 356±62.35 mL and a mean hospital stay of 15 ± 4.61 days in these cases. One patient had bile leakage and 3 patients had pleural effusion postoperatively, and they were discharged after drainage and medications. No liver failure or death occurred in these cases perioperatively.@*CONCLUSIONS@#3D visualization and 3D printing can facilitate accurate preoperative assessment, surgical planning and surgical procedure optimization for Bismuth-Corlette type Ⅲ and Ⅳ hilar cholangiocarcinoma to improve surgical safety and reduce surgical risks especially in cases of intrahepatic vascular variations.

Research on the precision of virtual surgical planning in two⁃jaw orthognathic surgery / 口腔疾病防治

Objective@#To provide a clinical reference by evaluating the precision of virtual surgical planning in two⁃ jaw orthognathic surgery.@*Methods @#Thirty consecutive patients who required two⁃jaw orthognathic surgery were includ⁃ ed. A composite skull model was reconstructed using data from spiral computed tomography scan and surface scanning of the dental arch. LeFort I osteotomy of the maxilla and bilateral sagittal split ramus osteotomy of the mandible were simulated using Dolphin Imaging 11.7 Premium. Genioplasty was performed if indicated. Virtual plan was then trans⁃ ferred to operation room using 3D⁃printed surgical templates. Frankfort horizontal plane (FHP), midfacial plane (perpen⁃ dicular to the FHP through the nasion), and coronal plane (perpendicular to the FHP through the sella point) were the selected three symmetry planes.Midpoint of the contact of the maxillary and mandibular central incisors (UI, LI), and the mesio⁃buccal cusp of the first maxillary and mandibular molars (U6⁃R,U6⁃L, L6⁃R, L6⁃L) were the six chosen volu⁃metric landmarks. To calculate the linear difference and overall mean linear difference (mean difference of the distance between UI, LI, U6⁃R, U6⁃L, L6⁃R, L6⁃L to FHP, midfacial and coronal plane) between simulated and postoperative models, the distance between selected landmarks and symmetry planes was measured. To calculate the angular differ⁃ ence and overall mean angular difference, values of the angles constructed by the occlusal, palatal, and mandibular plane to FHP and midfacial plane respectively were determined on simulated and postoperative models@* Results@#The virtual surgical planning was successfully transferred to actual surgery with the help of 3D⁃printed surgical templates. All patients were satisfied with the postoperative facial profile and occlusion. The overall mean linear difference was 0.81 mm (0.71 mm for maxilla and 0.91 mm for mandible); and the overall mean angular difference was 0.95° (the mean angular difference relative to FHP was 1.10°, and that relative to midfacial plane was 0.83°)@* Conclusion@#Virtual sur⁃ gical planning facilitated the diagnosis, treatment planning, and precise bony segments repositioning in two⁃jaw orthog⁃ nathic surgery.

Dimensional Accuracy of 3D-printed Models of the Right First Metacarpal Bones of Cadavers

Background@#The use of 3D printing in medical education, prosthetics, and preoperative planning requires dimensional accuracy of the models compared to the replicated tissues or organs. Objective. To determine the dimensional accuracy of 3D-printed models replicated from metacarpal bones from cadavers. @*Methods@#Fifty-two models were 3D-printed using fused deposition modeling (FDM), stereolithography (SLA), digital light processing (DLP), and binder jetting method from 13 right first metacarpal bones of cadavers from the College of Medicine, University of the Philippines Manila. Six dimensional parameters of the 3D-printed models and their control bones were measured using 0.01 mm calipers — length, midshaft diameter, base width, base height, head width, and head height. Mean measurements were compared using non-inferiority testing and multidimensional scaling.@*Results@#Mean measurements of the 3D-printed models were slightly larger than their control bones (standard deviation range: 1.219-4.264; standard error range, 0.338-1.183). All models were found to be at least 90% accurate and statistically non-inferior compared to control bones. DLP-printed models were the most accurate (base width, 99.62 %) and most similar to their control bone (–0.05, 90% CI –0.34, 0.24). Through multidimensional scaling, DLP-printed models (coordinate = 0.437) were the most similar to the control bone (coordinate = 0.899).@*Conclusion@#The 3D-printed models are dimensionally accurate when compared to bones.

Accuracy and precision of measurements performed on three-dimensional printed pelvises when compared to computed tomography measurements

The preoperative contouring of plates decreases the duration of surgery and improves the quality of the reduction of pelvic fractures. Patient-tailored three-dimensionally printed pelvises might be an interesting tool for achieving that purpose. Currently, no study has evaluated the accuracy of measurements performed on three-dimensional printed models in comparison with computed tomography data for complex bones, such as the pelvis. This study examined whether the measurements obtained on pelvises printed using dual-material fused deposition modeling technology are not significantly different from those obtained on computed tomography images. The computed tomography images of the pelvic region from 10 dogs were used to produce three-dimensionally printed models with a dual-material fused deposition-modeling process. Four segments were measured on both three-dimensionally printed models and computed tomography images. The measurements were performed by three observers and repeated twice. Concordance correlation coefficients were used to assess the precision and accuracy of the measurements as well as evaluate the agreement between the methods. The accuracy of measurements between the methods was > 0.99 for all measurements. The precision was almost perfect for AE (0.996), substantial for BD and BC (0.963 and 0.958, respectively), and moderate for CD (0.912). These results indicate that, despite some minor variations, the measurements performed on printed models reproduced the computed tomography data reliably.

The planning, simulating and executing for the surgery of bilateral renal masses used the three-dimensional intelligent qualitative and quantitative analysis system(IQQA) / 中华泌尿外科杂志

Objective To explore the application of three-dimensional intelligent qualitative and quantitative analysis system (IQQA) in the planning,simulation and implementation of precise surgery for bilateral renal tumors.Methods A retrospective analysis a total of 7 patients with bilateral kidney tumors in our center from June 2017 to August 2018 was performed.There were 5 males and 2 females,with an average age of (54.6 ± 6.0) years,ranging 47.0-63.0 years.The average BMI index was (23.4 ± 2.4) kg/m2,ranging 21.2-28.0 kg/m2.The average diameter of 14 renal tumors in 7 patients was (3.8 ± 1.1) cm,ranging 1.9-5.3 cm.The average R.E.N.A.L score was 6.6 ± 1.2,ranging 5.0-9.0.The tumor stage was T1N0M0.The mean preoperative hemoglobin,albumin,creatinine and GFR were (138.6 ± 17.0)g/L and (47.3 ± 2.5 g/L),(51.6 ± 19.1) μmol/Land (56.9 ± 6.7) ml/min,respectively.Before operation,the original data of CT were input into IQQA system.Then we reconstructed kidney,blood vessel,collecting system and tumors using system.And the structure of kidney,tumors and vessels was visualized directly.The systematic analysis of the operation is carried out at terminals vary from various angles,and the surgical resection simulation.The position,angle and curvature of the cut surface are adjusted according to the effect.The plan of partial nephrectomy is designed.The resection area,remaining area of kidney is calculated.In this way,we can construct individualized and accurate laparoscopic partial nephrectomy planning before operation.Last,we carried out the operation according to the designed plan.The laparoscopic standard partial nephrectomy was performed in 11 cases.The laparoscopic selective partial nephrectomy was performed in 2 cases.One underwent laparoscopic partial nephrectomy without obstruction.We achieved precise resection of tumors and rapid suture of wounds according to the preoperative planning of excision and suture.We collected of the surgical success rate,conversion to opening rate,operation time,warm ischemia time,intraoperative bleeding volume,complications and hospitalization after operation.The related laboratory indicators such as eGFR and creatinine were followed up for 3 months,and the prognostic indicators such as renal CT and pulmonary CT for 6 months after operation were evaluated and analyzed.Result 14 renal tumors were successfully reconstructed by IQQA in 7 patients.The operations were completed successfully without conversion to open surgery or radical nephrectomy.The average operative duration was (68.9 ± 9.2) minutes,ranging 50.0-80.0 minutes.The average renal artery occlusion duration was (20.7 ± 4.1) minutes,ranging 15.0-29.0 minutes.The average intraoperative bleeding volume was (70.7 ± 29.7) ml,ranging 30.0-120.0 ml.The average indwelling time of drainage tube was (5.5 s0.7) days,ranging 5.0-7.0 days.The average hospitalization time was (6.3 ± 0.5) days,ranging 6.0-7.0 days.There were no perioperative complications such as bleeding,urinary leakage,infection,incision dehiscence and pulmonary infection.Postoperative pathology revealed 13 clear cell renal carcinoma and 1 renal angiomyoma.No recurrence or metastasis was found in chest CT and lung CT after 6 months follow-up.The creatinine and GFR in 3 months after operation were (52.0 ± 15.2) μmol/L(36.0-72.0 μmol/L) and (56.7 ± 5.3) ml/min(46.7-66.3 ml/min).There was no significant difference of creatinine and GFR with the preoperative (P ＞ 0.05).The mean Hb and albumin levels in 3 months after operation were (120.9 ± 17.0) g/L(90.0-147.0 g/L) and (41.4 ± 2.6) g/L (38.0-46.0 g/L),which were significantly lower than those before operation (P ＜ 0.05).Conclusions The three-dimensional intelligent qualitative and quantitative analysis system (IQQA) can visualize the kidney,tumor and the vasculature of bilateral kidney tumors by preoperative three-dimensional reconstruction.The optimal surgical plan of partial nephrectomy can be designed by preoperative operation planning and computer terminal in order to enhance the safety of partial nephrectomy for bilateral kidney tumors and preserve the possibility of kidney,and protect the renal function to the greatest extent.To accurately predict the retention of renal function after operation,so that patients with bilateral renal tumors can get the greatest benefit in partial nephrectomy.

Applications of three-dimensional surface imaging in the plastic and aesthetic breast surgery / 中华整形外科杂志

Three-dimensional surface imaging (3D-SI) can objectively evaluate the shape of body surface, and has been widely used in the plastic and aesthetic surgery. The authors make a review of this technique in the breast surgery, which contains the introduction of 3D-SI, the accuracy and reproducibility of 3D-SI in breast symmetry evaluation, and the applications of 3D-SI in preoperative surgical planning, postoperative effect evaluation, and follow-up observation. Most of the literatures show promising results, indicating that this technique has good prospects in the plastic and aesthetic breast surgery. However, there is still lack of evidence of its superiority over other methods from multicenter large sample randomized controlled studies.

Malignant perineal tumors in dogs: the contribution of computed tomography for staging and surgical planning / Tumores perineais malignos em cães: contribuição da tomografia computadorizada para estadiamento e planejamento cirúrgico

The contribution of computed tomography for staging and surgical planning of malignant perineal tumors in dogs is discussed. Five dogs diagnosed with malignant perineal neoplasms underwent to computed tomography (CT) examination. The CT image enabled investigation of cleavage planes between neoplastic lesions and adjacent structures such as the rectum, anus, vagina, urethra and perineal muscles. Accurate assessment regional lymph nodes and adjacent bone structures was also possible. All tumors evaluated in this region presented heterogeneous appearance in pre and postcontrast CT images, but only the anal sac adenocarcinomas presented lymphadenopathy. Computed tomography proved to be a valuable tool for tumor staging and determination of lesion extension and invasion of adjacent tissues, providing significant contributions to clinical and surgical therapeutic planning.(AU)

A contribuição da tomografia computadorizada para estadiamento e planejamento cirúrgico de tumores perineais malignos em cães é discutida. Cinco cães diagnosticados com neoplasias perineais malignas foram submetidos ao exame de tomografia computadorizada (CT). A imagem por TC permitiu a investigação de planos de clivagem entre as lesões neoplásicas e estruturas adjacentes, como o reto, o ânus, a vagina, a uretra e os músculos perineais. A avaliação precisa dos linfonodos regionais e estruturas ósseas adjacentes também foi possível. Todos os tumores avaliados nesta região apresentaram aspecto heterogêneo nas imagens de TC pré e pós-contraste, mas apenas os adenocarcinomas de saco anal apresentaram linfonodopatia. A tomografia computadorizada mostrou ser uma ferramenta valiosa para o estadiamento da neoplasia, determinação da extensão da lesão e invasão de tecidos adjacentes, proporcionando contribuições significativas para o planejamento terapêutico clínico e cirúrgico.(AU)

Una actualización sobre aplicaciones ortopédicas usando tecnologías de impresión tridimensional / An Update on Orthopedic Applications Using 3-Dimensional Printing Technologies / Uma atualização em aplicações ortopédicas usando tecnologias de impressão tridimensionais

Resumen En este artículo se revisan las aplicaciones tecnológicas de la impresión tridimensional (3DP) en Ortopedia. La impresión 3D es el proceso de manufacturar para construir objetos tridimensionales a través de la acumulación de material, y recientemente está llamando la atención de profesionales médicos de forma significativa. La Ortopedia es probablemente la mayor área de aplicación de esta tecnología, y está siendo probada en diversos procedimientos, desde hacer planeación quirúrgica hasta manufacturar implantes para probar su utilidad. Sin embargo, esta tecnología no ha superado completamente los problemas que surgieron en la década de los noventa, estas limitaciones serán superadas eventualmente cuando la velocidad del desarrollo tecnológico sea considerada.

Abstract This article reviews the technological applications of 3-dimensional printing (3DP) in orthopedics. 3DP is the manufacturing process to build three-dimensional object by accumulating material, and recently it is drawing the interest of medical professional significantly. Orthopedics is probably the biggest application of this technology, and is being tested from surgical planning to the implant manufacturing to prove its usefulness. The technology has not overcome the problems that arose in the 90s completely, those limitations will be overcome eventually, when the technological development speed is considered.

Resumo Este artigo descreve as aplicações tecnológicas da impressão tridimensional (3DP) em Ortopedia. Impressão 3D é o processo de manufatura para construir objectos tridimensionais, através da acumulação de material. Recentemente elas estao atraindo significativamente a atenção dos profissionais médicos. A Ortopedia é provavelmente a maior área de aplicação desta tecnologia, e está sendo testado em vários processos, desde o planejamento cirúrgico até a fabricação de implantes cirúrgicos para provar a sua utilidade. No entanto, esta tecnologia não foi consigue superar completamente os problemas que surgiram na década dos noventa. Essas limitações serao superadas quando a velocidade do desenvolvimento tecnológico seja considerado.

Application of digital surgery for orthognathic surgical planning / 口腔疾病防治

@#The success of orthognathic surgery depends not only on surgical techniques but also on accurate and scientific surgical design and planning. The adoption of digital surgery has created a paradigm shift in surgical planning. However, compared with traditional methods, digital surgery-assisted planning of an orthognathic operation differs fundamentally from planning using traditional methods, including the elimination of plaster dental model surgery and of the increase in splint design accuracy. This article focuses on the application of digital virtual tools for pre-operative design of orthognathic surgery to provide a virtual surgical procedure reference for surgeons who need to incorporate digital surgery into orthognathic surgery.