Prótesis Totales Digitales 3D fabricadas por CAD-CAM: Revisión bibliográfica / 3D Digital Denture Complete manufactured by CAD-CAM: Literature review

El artículo se centra en la aplicación de tecnología CAD/CAM en la odontología, específicamente en la fabricación de prótesis dentales totales. Este avance ha transformado la forma en que se diseñan y producen estas prótesis, emergiendo la fabricación de ella mediante capas sucesivas a base de tecnologías de impresión 3D como la estereolitografía, el procesamiento digital de luz y la pantalla de cristal líquido. En la presente revisión se profundizó en aspectos clínicos y biomecánicos, evaluando la retención, adaptación de la base, resistencia a la flexión y límite elástico de las prótesis. Los resultados indican que las prótesis digitales ofrecen mejor retención y adaptación en comparación con los métodos convencionales, aunque no hay diferencias estadísticamente significativas en resistencia a la flexión. También se exploraron aspectos económicos, destacando la reducción de costos y ahorro de tiempo en el proceso clínico con el enfoque digital. Los pacientes experimentan mayor satisfacción con prótesis impresas en 3D en términos de comodidad y eficiencia. Sin embargo, existen limitaciones, como la dificultad en la evaluación estética de prótesis monocromáticas, además de la dependencia de técnicas convencionales para evaluar la funcionalidad del paciente. La tecnología CAD/CAM ha revolucionado la fabricación de prótesis dentales totales, ofreciendo ventajas y beneficios. Este avance tecnológico promete mantener su relevancia en la comunidad científica y odontológica.

The article focuses on the application of CAD/CAM technology in dentistry, specifically in the manufacturing of complete dentures. This advance has transformed the way these dentures are designed and produced, with the manufacturing of layers emerging through successive 3D printing technologies such as stereolithography, digital light processing and liquid crystal display. In the present review clinical and biomechanical aspects were delved into, evaluating retention, adaptation of the base, resistance to flexion and elastic limit of the prostheses. The results indicate that digital prostheses offer better retention and adaptation compared to conventional methods, although there are no statistically significant differences in bending resistance. Economic aspects were also explored, highlighting the cost reduction and time savings in the clinical process with the digital approach. Patients experience greater satisfaction with 3D printed dentures in terms of comfort and efficiency. However, there are limitations, such as the difficulty in the aesthetic evaluation of monochromatic dentures, in addition to the dependence on conventional techniques to evaluate the patient's functionality. CAD/CAM technology has revolutionized the manufacturing of total dental prostheses, offering advantages and benefits. These technological advance promises to maintain its relevance in the scientific and dental community.

Use of Three-dimensional Printing for Tibial Pilon Fracture Diagnosis and Treatment / Uso da impressão tridimensional para auxílio diagnóstico e terapêutico das fraturas de pilão tibial

Abstract Objective To evaluate whether three-dimensional (3D) printing increases agreement in the classification of tibial pilon fractures. Methods Orthopedists and traumatologists reviewed radiographs, computed tomography scans with 3D reconstruction, and prototyping 3D printing, and classified the fractures based on the Rüedi-Allgöwer and Arbeitsgemeinschaft für Osteosynthesefragen (AO, Association for the Study of Internal Fixation) Foundation/Orthopedic Trauma Association (AO/OTA) classification systems. Next, data evaluation used Kappa agreement coefficients. Results The use of the 3D model did not improve agreement for tibial pilon fractures regarding the treatment proposed by the groups. Regarding the classification systems, the agreement only improved concerning the AO/OTA classification when the 3D model was used in the assessment by the foot and ankle specialists. Conclusion Although 3D printing is statistically relevant for surgeons specializing in foot and ankle, its values remain lower than optimal.

Resumo Objetivo Avaliar se a impressão tridimensional (3D) aumenta a concordância na classificação de fraturas do pilão tibial. Métodos Foram selecionadas radiografias, tomografias com reconstrução 3D e impressão de prototipagem em impressora 3D. Os exames foram apresentados a profissionais da área de Ortopedia e Traumatologia que classificaram as fraturas com base nas classificações da Arbeitsgemeinschaft für Osteosynthesefragen (AO, Associação para o Estudo da Fixação Interna) Foundation/Orthopedic Trauma Association (AO/OTA) e de Rüedi-Allgöwer. Posteriormente, os dados foram avaliados pelos coeficientes de concordância de Kappa. Resultados O uso do modelo 3D não melhorou a concordância na fratura do pilão tibial quanto ao tratamento proposto pelos grupos. Em relação aos sistemas de classificação, somente a concordância na classificação AO/OTA melhorou quando foi utilizado o modelo 3D na avaliação pelos especialistas em pé e tornozelo. Conclusão Apesar de o uso da impressão 3D ter relevância estatística para os cirurgiões especialistas em pé e tornozelo, ainda apresenta valores menores do que os ideais.

3D printed metal augment or tibial prosthesis for reconstruction of large bone defects in total knee arthroplasty and revision surgery / 中华骨科杂志

Objective:To investigate the clinical efficacy of 3D printed metal augment or tibial prosthesis for reconstruction of large bone defects in total knee arthroplasty (TKA) and knee revision surgery.Methods:A total of 7 patients (7 knees) with TKA or knee revision who were admitted to the Department of Orthopaedics of the Second Affiliated Hospital of Zhejiang University School of Medicine with large bone defects from July 2018 to December 2023 were retrospectively analyzed, including 4 patients with TKA and 3 patients with knee revision. There were 3 males and 4 females, aged 58.7±7.6 years (range, 54-68 years), 3 patients with left knee and 4 patients with right knee. All the patients had bone defects in the knee joint (AORI type III), 2 cases had bone defects only in the femur, 4 cases had bone defects only in the tibia, and 1 case had bone defects in both the tibia and femur, which were treated with personalized reconstruction using 3D printing. Hip-knee-ankle angles, American Knee Society score (KSS) before and after surgery were compared, and postoperative complications were observed.Results:All patients successfully completed the operation, and the operation time was 189.3±35.5 min (range, 125-240 min). Complex TKA was performed in 4 cases with surgical times of 175, 195, 210, and 240 min, and revision surgery was performed in 3 cases with surgical times of 125, 180, and 200 min, respectively. Intraoperative blood loss was 114±24.4 ml (range, 100-150 ml). Five cases used 3D printed metal augment, and two used 3D printed one-piece tibial components. All patients were followed up for 2, 2, 5, 6, 7, 20, 57 months, respectively. The KSS of the five patients at 3 months postoperatively were 56, 61, 66, 56, and 56 points, respectively, greater than the preoperative scores of 35, 44, 36, 27, and 41 points. The KSS functional scores of the five patients at 3 months postoperatively were 45, 45, 45, 30, and 45 points, respectively, which were greater than the preoperative scores of 30, 30, 15, 20, and 20 points. The hip-knee-ankle angle was 181.8°±3.4° (range, 177.9° to 188.0°) at the final follow-up and 175.8°±12.4° (range, 153.3° to 192.1°) before surgery, with no significant difference ( t=-1.230, P=0.242). At the final follow-up, the 3D printed component was well integrated with the bone surface, the prosthesis was securely positioned, and the force lines of the lower limbs were normal. There were no postoperative complications such as poor wound healing, infection, fat liquefaction, nerve injury, deep vein thrombosis of lower limbs, knee joint stiffness, periprosthesis infection and loosening. Conclusion:Using 3D printed metal augment or tibial prosthesis to reconstruct the huge bone defect in TKA and revision has a satisfactory early clinical effect, satisfactory joint function and good surgical safety.

Evaluation of short-term effects on 3D printing patient-matched artificial vertebral body in clinical research and application / 中华骨科杂志

Objective:To evaluate the short-term efficacy and safety of 3D printing patient-matched artificial vertebral body in clinical research and application.Methods:A total of 12 patients with spinal tumors were enrolled 7 males (58.33%) and 5 females (41.67%), aged from 18 to 65 years old in The First Affiliated Hospital of Air Force military Medical University (hereinafter referred to as Xijing Hospital) and Peking University people's Hospital from September 2021 to July 2022. The spinal vertebra defect were restored by using 3D printing patient-matched artificial vertebral body after tumor resection. All patients who accepted TES and 3D printing patient-matched artificial vertebral body implantation were included according to the inclusion and exclusion criteria. The bone interface fusion was evaluated by the imaging fusion criteria of Brantigan and Steffee at 3 and 6 months after operation, the curative effect was evaluated by comparing Japanese Orthopaedic Association (JOA) score at 3 and 6 months after operation, visual analogue scale (VAS) 3 months after operation and intervertebral height at 3 and 6 months after operation with those before operation, and the safety was evaluated by adverse event recording.Results:All 12 patients completed the operation successfully, and the operation sites were thoracic vertebrae in 6 cases (50%), thoracolumbar in 3 cases (25%) and lumbar vertebrae in 3 cases (25%). All patients were followed up. The mean follow-up time was 23.92±3.23 months (range, 19-29 months). No tumor recurrence or metastasis was observed during this period. All patients were followed up at 15 days, 3 months and 6 months after operation. During the 6-month follow-up, X ray results showed that interface of bone and the vertebral body were fused in all of the 12 patients, and the effective rate of fusion was 100%. The 95% confidence interval is calculated to be (75.6%-100%). Six months after operation, the improvement rate of JOA score was excellent in 10 cases, good in 1 case, poor in 1 case, and the excellent and good rate was 91.66%. The preoperative VAS score was 4.08 ±2.47, and during the 3-month follow-up, the VAS score was improved to 1.83 ±1.59. Compared with the preoperative VAS score, the difference was statistically significant ( t=2.635, P=0.023). The intervertebral height before operation, 15 days after operation, 3 months after operation and 6 months after operation were 32.75 (25.94, 68.20), 41.09 (30.55, 70.20), 40.70 (30.23, 67.83) and 40.74 (30.23, 67.08), respectively, and there was no statistically significant difference (χ 2=0.768, P=0.857). No implant-related adverse events occurred after operation. Conclusion:The 3D printing patient-matched artificial vertebral body used in this study has satisfactory short-term efficacy and safety in the reconstruction of spinal stability after spinal tumor resection.

Application of three-dimensional printing technology in obstetrics / 中华围产医学杂志

Three-dimensional (3D) printing, also known as additive manufacturing, is a fabrication technology that constructs three-dimensional objects by successive addition of materials. In recent years, the advancements in 3D printing technology, reductions in material costs, development of biomaterials, and improvements in cell culture techniques allow the application of 3D printing in the clinical medical fields, such as orthopedics, dentistry, and urinary surgery, to develop rapidly. Obstetrics, focusing on both theory and practice, is an emerging application field for 3D printing technology. 3D printing has been used in obstetrics for fetal and maternal diseases, such as prenatal diagnosis of fetal abnormalities and preoperative planning for placental implantation disorders. Additionally, 3D printing can simulate surgical scenarios and enable the targeted training for doctors. This review aims to provide a summary of the latest developments in the clinical application of 3D printing in obstetrics.

Research status and prospect of hydrogel preparation for artificial cornea / 中华实验眼科杂志

Currently, the dominating treatment of corneal blindness is corneal transplantation, but the shortage of corneal donors has been a major problem in corneal transplantation.Compared with the traditional preparation method of artificial cornea, with the emergence of new materials, new technologies and new commercial activities, hydrogel provides a new possibility for the preparation of artificial cornea.Hydrogel is similar to the equivalent of extracellular matrix, with high biocompatibility, low immunogenicity and other characteristics, so it has been popularized and applied in many industries.As an important material of regenerative medicine, hydrogel has shown a strong application prospect in pharmaceutical research, 3D cell culture, stem cell research, 3D printing bio-ink and other fields.The main materials used for generating hydrogels are hyaluronic acid, gelatin, sodium alginate, etc.A lot of researches on using hydrogels as materials combined with different 3D printing technologies to prepare artificial corneas have been carried out and certain technical and theoretical breakthroughs have been made.This article briefly reviewed the research progress of hydrogel combined with 3D printing in the preparation of artificial cornea.

Development and mechanical-functional validation of 3D-printed laparoscopic forceps / Desenvolvimento e validação mecânico-funcional de pinça laparoscópica impressa em 3 dimensões

ABSTRACT Introduction: 3-dimensional printing has enabled the development of unique and affordable additive manufacturing, including the prototyping and production of surgical forceps. Objective: demonstrate the development, 3D printing and mechanical-functional validation of a laparoscopic grasping forceps. Methods: the clamp was designed using a computer program and printed in 3 dimensions with polylactic acid (PLA) filament and added 5 screws for better leverage. Size and weight measurements were carried out, as well as mechanicalfunctional grip and rotation tests in the laboratory with a validated simulator. Results: Called "Easylap", the clamp weighed 48 grams, measured 43cm and was printed in 8 pieces, taking an average of 12 hours to produce. It allowed the simulation of the functional characteristics of laparoscopic pressure forceps, in addition to the rotation and rack locking mechanism. However, its strength is reduced due to the material used. Conclusion: It is possible to develop plastic laparoscopic grasping forceps through 3-dimensional printing.

RESUMO Introdução: a impressão em 3 dimensões permitiu o desenvolvimento de manufaturas aditivas únicas e acessíveis, inclusive na prototipagem e produção de pinças cirúrgicas. Objetivo: Demonstrar o desenvolvimento, a impressão em 3D e a validação mecânico-funcional de pinça laparoscópica do tipo apreensão. Métodos: a pinça foi desenhada em programa de computador e impressa em 3 dimensões com filamento de ácido poliláctico (PLA) e acrescida de 5 parafusos para melhor efeito de alavanca. Foram realizadas aferições de tamanho e peso, bem como testes mecânicos-funcionais de preensão e rotação em laboratório com simulador validado. Resultados: denominada "Easylap", a pinça pesou 48 gramas, mediu 43 cm e foi impressa em 8 peças, levando em média 12 horas para sua produção. Ela permitiu a simulação das características funcionais de pinça laparoscópicas de apreensão, além de mecanismo de rotação e travamento por cremalheira. Porém sua força é reduzida devido ao material utilizado. Conclusão: é possível desenvolver pinça laparoscópica plástica de apreensão através de impressão em 3 dimensões.

Influence of fabrication method on the marginal fit of temporary restorations

Abstract Computer-aided manufacturing (CAM) technology allows the use of different manufacturing techniques. This in vitro study aimed to evaluate the marginal fit of temporary restorations manufactured using conventional chairside methods, milling, and three-dimensional printing. Fifteen 3-element temporary restorations specimens were produced and categorized into three groups: non-digital, obtained using the conventional chairside method (GC); milled (GM); and three-dimensionally printed (GP). Marginal fit was assessed using scanning electron microscopy (SEM) performed under two conditions: one with only the central screw tightened, and the other with all three screws tightened. Horizontal misfit values were categorized as over-, equal-, and under-extended and qualitatively analyzed. Statistical analysis was performed using the Tukey-Kramer test (α=0.05). In the vertical assessment, three-dimensionally printed restorations demonstrated greater misfit than restorations obtained by milling and the conventional chairside method (P<0.05). In the horizontal assessment, the misfit in the GP group was significantly higher than that in the GM and GC groups. Restorations obtained using the conventional chairside method and milled provisional restorations showed more favorable results than three-dimensionally printed restorations.

Methodology for Preoperative Planning of Bone Deformities Using Three-dimensional Modeling Software / Metodologia para planejamento pré-operatório de deformidades ósseas utilizando software de modelagem tridimensional

Abstract Rapid prototyping technology, known as three-dimensional (3D) printing, and its use in the medical field are advancing. Studies on severe bone deformity treatment with 3D printing showed benefits in postoperative outcomes thanks to this technology. Even so, preoperative planning guidance for surgeons is lacking. This technical note describes a practical step-by-step guide to help surgeons use this technology to optimize the therapeutic plan with free license software and an intuitive interface. This study aims to organize the 3D modeling process using a preoperative computed tomography (CT) scan. This technology allows a deeper understanding of the case and its particularities, such as the direction, planes, and dimensions of the deformity. Planning considering these topics may reduce the surgical time and result in better functional outcomes by understanding the deformity and how to correct it. Associating planning via software with 3D printing can further enhance this therapeutic method.

Resumo Observa-se o avanço da tecnologia de prototipagem rápida, conhecida como impressão tridimensional (3D) e seu uso na área médica. Existem estudos a respeito do tratamento de deformidades ósseas graves com impressão 3D, os quais mostram benefícios no resultado pós-operatório às custas do uso da tecnologia em questão. Ainda assim, nota-se a escassez quando o assunto é disponibilizar ao cirurgião orientações para planejamento pré-operatório. O objetivo desta nota técnica é descrever um passo-a-passo prático para auxiliar cirurgiões a utilizarem a tecnologia como ferramenta para otimizar o plano terapêutico, dispondo de um programa de licença gratuita e de interface intuitiva. Este é um estudo que visa a organização do processo de modelagem 3D, no qual foi utilizado um exame de tomografia computadorizada (TC) pré-operatória. Com esta tecnologia, é possível uma compreensão mais profunda do caso e suas particularidades como direção, planos e dimensões das deformidades. Acredita-se que um planejamento que leve em consideração tais tópicos gera redução do tempo cirúrgico e melhores resultados funcionais devido ao entendimento da deformidade e maneiras de correção. Associar o planejamento via software com a impressão 3D pode potencializar ainda mais na elaboração do método terapêutico.

Three-dimensional models of physeal fractures in the femur for the teaching of veterinary medicine

ABSTRACT Purpose: To develop and assess three-dimensional models of physeal fractures in dog femurs (3D MPFDF) using radiographic imaging. Methods: The study was conducted in three phases: development of 3D MPFDF; radiographic examination of the 3D MPFDF; and comparative analysis of the anatomical and radiographic features of the 3D MPFDF. Results: The base model and the 3D MPFDF achieved high fidelity in replicating the bone structures, accurately maintaining the morphological characteristics and dimensions such as length, width, and thickness, closely resembling natural bone. The radiographs of the 3D MPFDF displayed distinct radiopaque and radiolucent areas, enabling clear visualization of the various anatomical structures of the femur. However, in these radiographs, it was challenging to distinguish between the cortical and medullary regions due to the use of 99% internal padding in the printing process. Despite this limitation, the radiographs successfully demonstrated the representation of the Salter-Harris classification. Conclusions: This paper presents a pioneering project focused on technological advancement aimed at developing a method for the rapid and cost-effective production of three-printed models and radiographs of physeal fractures in dogs.

Simulators in urology resident's training in retrograde intrarenal surgery

ABSTRACT Purpose: To evaluate the impact of simulators on the training of urology residents in retrograde intrarenal surgery (RIRS). Methods: The study involved training eight urology residents, using two artificial simulators; one developed by the Universidade Estadual do Pará, using three-dimensional printing technology, and the other one patented by the medical equipment manufacturer Boston Scientific The qualification of residents took place through a training course, consisting of an adaptation phase (S0), followed by three training sessions, with weekly breaks between them (S1, S2 and S3). Study members should carry out a RIRS in a standardized way, with step-by-step supervision by the evaluator using a checklist. The participants' individual performance was verified through a theoretical assessment, before and after training (pre- and post-training), as well as by the score achieved in each session on a scale called global psychomotor skill score. In S3, residents performed an analysis of the performance and quality of the simulation, by completing the scale of student satisfaction and self confidence in learning (SSSCL). Results: At the end of the course, everyone was able to perform the procedure in accordance with the standard. The training provided a learning gain and a considerable improvement in skills and competencies in RIRS, with p < 0.05. SSSCL demonstrated positive feedback, with an overall approval rating of 96%. Conclusions: Artificial simulators proved to be excellent auxiliary tools in the training of urology residents in RIRS.

Analysis of the Mechanical Behavior of Porcine Graft Fixation in a Polyurethane Block Using a 3D-printed PLA Interference Screw / Análise do comportamento mecânico da fixação do enxerto suíno em um bloco de poliuretano usando um parafuso de interferência PLA impresso em 3D

Abstract Objective The interest in using 3D printing in the healthcare field has grown over the years, given its advantages and potential in the rapid manufacturing of personalized devices and implants with complex geometries. Thus, the aim of the present study was to compare the mechanical fixation behavior of a 3D-printed interference screw, produced by fused deposition modeling of polylactic acid (PLA) filament, with that of a titanium interference screw. Methods Eight deep flexor porcine tendons, approximately 8 mm wide and 9 cm long, were used as graft and fixed to a 40 pounds-per-cubic-foot (PCF) polyurethane block at each of its extremities. One group was fixed only with titanium interference screws (group 1) and the other only with 3D-printed PLA screws (BR 20 2021 018283-6 U2) (group 2). The tests were conducted using an EMIC DL 10000 electromechanical universal testing machine in axial traction mode. Results Group 1 (titanium) obtained peak force of 200 ± 7 N, with mean graft deformation of 8 ± 2 mm, and group 2 (PLA) obtained peak force of 300 ± 30 N, and mean graft deformation of 7 ± 3 mm. Both the titanium and PLA screws provided good graft fixation in the polyurethane block, with no slippage or apparent deformation. In all the samples, the test culminated in graft rupture, with around 20 mm of deformation in relation to the initial length. Conclusion The 3D-printed PLA screw provided good fixation, similar to that of its titanium counterpart, producing satisfactory and promising results.

Resumo Objetivo O interesse em utilizar a impressão 3D na área da saúde tem crescido ao longo dos anos, dadas as suas vantagens e o seu potencial na rápida fabricação de dispositivos e implantes personalizados com geometrias complexas. Assim, o objetivo do presente estudo foi comparar o comportamento de fixação mecânica de um parafuso de interferência impresso em 3D, produzido pela modelagem fundida de deposição do filamento de ácido polilático (PLA), com o de um parafuso de interferência de titânio. Métodos Oito tendões suínos flexores profundos, de aproximadamente 8 mm de largura e 9 cm de comprimento, foram utilizados como enxerto e fixados em um bloco de poliuretano de 40 PCF em cada uma de suas extremidades. Um grupo foi fixado apenas com parafusos de interferência de titânio (grupo 1) e o outro apenas com parafusos PLA impressos em 3D (BR 20 2021 018283-6 U2) (grupo 2). Os testes foram realizados utilizando uma máquina de teste universal eletromecânica EMIC DL 10.000 no modo de tração axial. Resultados O grupo 1 (titânio) obteve força máxima de 200 ± 7 N com deformação média do enxerto de 8 ± 2 mm, e a força máxima do grupo 2 (PLA) foi de 300 ± 30 N e deformação média do enxerto de 7 ± 3 mm. Ambos os parafusos de titânio e PLA forneceram boa fixação de enxerto no bloco de poliuretano, sem deslizamento ou deformação aparente. Em todas as amostras o teste culminou na ruptura do enxerto, com cerca de 20 mm de deformação em relação ao comprimento inicial. Conclusão O parafuso PLA impresso em 3D proporcionou boa fixação, semelhante à de sua contraparte de titânio, produzindo resultados satisfatórios e promissores.

Fratura idiopática de mandíbula atrófica / Idiopathic fracture of atrophic jaw / Fractura idiopática de mandíbula atrófica

Objetivo: Discorrer sobre o tratamento cirúrgico de uma fratura idiopática de mandíbula atrófica. Relato de caso: Idosa compareceu à emergência de um hospital referência em traumas na Paraíba relatando dificuldade ao se alimentar, impossibilidade de uso da prótese dentaria, sintomatologia dolorosa em região mandibular direita com processo infeccioso ativo, sem histórico de trauma direto em face. Ao exame tomográfico constatou-se fratura em mandíbula atrófica com presença de dente incluso na região. Diante do quadro, optou-se por iniciar antibioticoterapia empírica e planejou-se tratamento cirúrgico de reconstrução mandibular com sistema load-sharing, tendo auxílio de biomodelo para conformação prévia da placa. Conclusão: O correto planejamento e escolha do sistema de fixação são fundamentais para o sucesso do tratamento. O uso de biomodelo com pré modelagem de placa mostrou-se positivo por otimizar o tempo cirúrgico, reduzindo os riscos inerentes ao procedimento nesta faixa etária e a utilização de sistema capaz de suportar a carga sofrida na estrutura óssea comprometida nestes casos é mandatório... (AU)

Objective: to discuss the surgical treatment of an idiopathic fracture of the atrophic mandible. Case report: elderly woman attended the emergency department of the Emergency and Trauma Hospital Dom Luiz Gonzaga Fernandes, in Campina Grande, Brazil. The patient reported pain on eating and inability to use her denture as painful symptoms in the right mandibular region with active fistula, without any records of facial trauma. Tomographic examination revealed an atrophic mandibular fracture with an impacted tooth in the region. The following procedures were performed: antibiotic therapy, surgical fixation using a 2.4mm pre-molded plate, shaped using a biomodel, and fistulectomy. Conclusion: Thus, to plan accordingly aiming to minimize the surgical time and its associate damage and the use of appropriate fixation systems capable of supporting the load on the compromised bone are essential to a successful treatment, specially with elderly patients due their general health condition and preexistent comorbities... (AU)

Objetivo: Discutir sobre el tratamiento quirúrgico de una fractura idiopática de la mandíbula atrófica. Caso clínico: Anciana compareció al servicio de urgencias del Hospital de Emergencia y Trauma de Campina Grande Dom Luiz Gonzaga Fernandes, PB, relatando dificultad para alimentarse, imposibilidad de uso de prótesis dental, sintomatología dolorosa en la región mandibular derecha con fístula activa, sin antecedentes de traumatismo directo en la cara. El examen tomográfico presentó una fractura mandibular atrófica con presencia de un diente incluido en la región. Como resultado se realizó antibioticoterapia, procedimiento de fijación quirúrgica con una placa de 2,4 mm premoldeada en biomodelo y fistulectomía. Conclusión: De esta forma, el correcto planeamiento para minimizar el tiempo quirúrgico y los daños asociados, principalmente en los ancianos por su estado general de salud y comorbilidades preexistentes, la utilización de sistemas de fijación adecuados capaces de soportar la carga sufrida en los huesos comprometidos, es fundamental para el éxito del tratamiento... (AU)

Application of 3D Printing Technology in the Treatment of Hoffa's Fracture Nonunion / Aplicação da tecnologia de impressão 3D no tratamento da pseudartrose da fratura de Hoffa

Abstract Objective To evaluate a proposed three-dimensional (3D) printing process of a biomodel developed with the aid of fused deposition modeling (FDM) technology based on computed tomography (CT) scans of an individual with nonunion of a coronal femoral condyle fracture (Hoffa's fracture). Materials and Methods Thus, we used CT scans, which enable the evaluation of the 3D volumetric reconstruction of the anatomical model, as well as of the architecture and bone geometry of sites with complex anatomy, such as the joints. In addition, it enables the development of the virtual surgical planning (VSP) in a computer-aided design (CAD) software. This technology makes it possible to print full-scale anatomical models that can be used in surgical simulations for training and in the choice of the best placement of the implant according to the VSP. In the radiographic evaluation of the osteosynthesis of the Hoffa's fracture nonunion, we assessed the position of the implant in the 3D-printed anatomical model and in the patient's knee. Results The 3D-printed anatomical model showed geometric and morphological characteristics similar to those of the actual bone. The position of the implants in relation to the nonunion line and anatomical landmarks showed great accuracy in the comparison of the patient's knee with the 3D-printed anatomical model. Conclusion The use of the virtual anatomical model and the 3D-printed anatomical model with the additive manufacturing (AM) technology proved to be effective and useful in planning and performing the surgical treatment of Hoffa's fracture nonunion. Thus, it showed great accuracy in the reproducibility of the virtual surgical planning and the 3D-printed anatomical model.

Resumo Objetivo Avaliar uma proposta de processo de impressão tridimensional (3D) de um biomodelo preparado com o auxílio da tecnologia de modelagem por deposição de material fundido (fused deposition modeling, FDM, em inglês) a partir de imagens de tomografia computadorizada (TC) de um indivíduo com pseudartrose de fratura coronal do côndilo femoral (fratura de Hoffa). Materiais e Métodos Para tanto, utilizamos imagens de TC, que permitem estudar a reconstrução volumétrica 3D do modelo anatômico, além da arquitetura e geometria óssea de sítios de anatomia complexa, como as articulações. Também permite o planejamento cirúrgico virtual (PCV) em um programa de desenho assistido por computador (computer-aided design, CAD, em inglês). Essa tecnologia possibilita a impressão de modelos anatômicos em escala real que podem ser utilizados em simulações cirúrgicas para o treinamento e a escolha do melhor posicionamento do implante de acordo com o PCV. Na avaliação radiográfica da osteossíntese da pseudartrose de Hoffa, verificou-se a posição do implante no modelo anatômico impresso em 3D e no joelho do paciente. Resultados O modelo anatômico impresso em 3D apresentou características geométricas e morfológicas semelhantes às do osso real. O posicionamento dos implantes em relação à linha de pseudartrose e pontos anatômicos foram bastante precisos na comparação do joelho do paciente com o modelo anatômico impresso em 3D. Conclusão A utilização do modelo anatômico virtual e do modelo anatômico impresso em 3D com a tecnologia de manufatura aditiva (MA) foi eficaz e auxiliou o planejamento e a realização do tratamento cirúrgico da pseudartrose da fratura de Hoffa. Desta forma, foi bastante preciso na reprodutibilidade do planejamento cirúrgico tanto virtual quanto no modelo anatômico impresso em 3D.

Effectiveness in Sterilization of Objects Produced by 3D Printing with Polylactic Acid Material: Comparison Between Autoclave and Ethylene Oxide Methods / Eficácia na esterilização de objetos produzidos pela impressão 3D com material ácido polilático: Comparação entre os métodos autoclave e óxido de etileno

Abstract Objective Due to the popularity of 3D technology, surgeons can create specific surgical guides and sterilize them in their institutions. The aim of the present study is to compare the efficacy of the autoclave and ethylene oxide (EO) sterilization methods for objects produced by 3D printing with polylactic acid (PLA) material. Methods Forty cubic-shaped objects were printed with PLA material. Twenty were solid and 20 were hollow (printed with little internal filling). Twenty objects (10 solid and 10 hollow) were sterilized in autoclave, forming Group 1. The others (10 solid and 10 hollow) were sterilized in EO, composing Group 2. After sterilization, they were stored and referred to culture. Hollow objects of both groups were broken during sowing, communicating the dead space with the culture medium. The results obtained were statistically analyzed (Fisher exact test and residue analysis). Results In group 1 (autoclave), there was bacterial growth in 50% of solid objects and in 30% of hollow objects. In group 2 (EO), growth occurred in 20% of hollow objects, with no bacterial growth in solid objects (100% of negative samples). The bacteria isolated in the positive cases was non-coagulase-producing Staphylococcus Gram positive. Conclusions Sterilization by both autoclave and EO was not effective for hollow printed objects. Solid objects sterilized by autoclave did not demonstrate 100% of negative samples and were not safe in the present assay. Complete absence of contamination occurred only with solid objects sterilized by EO, which is the combination recommended by the authors.

Resumo Objetivo Devido à popularidade da tecnologia 3D, cirurgiões podem criar guias cirúrgicos específicos e esterilizá-los nas suas instituições. O objetivo do presente estudo é comparar a eficácia dos métodos de esterilização por autoclave e óxido de etileno (OE) de objetos produzidos pela impressão 3D com material ácido polilático (PLA, na sigla em inglês). Métodos Quarenta objetos em formato cúbico foram impressos com material de PLA. Vinte eram sólidos e 20 eram ocos (impressos com pouco enchimento interno). Vinte objetos (10 sólidos e 10 ocos) foram esterilizados em autoclave, formando o Grupo 1. Os demais (10 sólidos e 10 ocos) foram esterilizados em OE, compondo o Grupo 2. Após a esterilização, os objetos foram armazenados e encaminhados para cultura. Objetos ocos de ambos os grupos foram quebrados durante a semeadura, comunicando o espaço morto com o meio de cultura. Os resultados obtidos foram analisados estatisticamente (teste exato de Fisher e análise de resíduo). Resultados No grupo 1 (autoclave) houve crescimento bacteriano em 50% dos objetos sólidos e em 30% dos objetos ocos. No grupo 2 (OE) o crescimento ocorreu em 20% dos objetos ocos, com ausência de crescimento bacteriano nos objetos sólidos (100% de amostras negativas). A bactéria isolada nos casos positivos foi Staphylococcus Gram positivo não produtor de coagulase. Conclusões A esterilização tanto em autoclave quanto pelo OE não foi eficaz para objetos impressos no formato oco. Objetos sólidos esterilizados em autoclave não demonstraram 100% de amostras negativas, não sendo seguro no presente ensaio. Ausência completa de contaminação ocorreu apenas com objetos sólidos esterilizados pelo OE, sendo a combinação recomendada pelos autores.

Percutaneous kyphoplasty assisted by three dimensional printing percutaneous guide plate for the treatment of osteoporotic vertebral compression fractures / 中国骨伤

OBJECTIVE@#To verify the safety of three dimensional printing percutaneous guide plate assisted percutaneous kyphoplasty(PKP) in the treatment of osteoporotic vertebral compression fractures(OVCFs).@*METHODS@#The clinical data of 60 patients with OVCFs treated by PKP from November 2020 to August 2021 were retrospectively analyzed. There were 24 males and 36 females, aged from 72 to 86 years old with an average of (76.5±7.9) years. Routine percutaneous kyphoplasty was performed in 30 cases (conventional group) and three dimensional printing percutaneous guide plate assisted PKP was performed in 30 cases (guide plate group). Intraoperative pedicle puncture time (puncture needle to posterior vertebral body edge) and number of fluoroscopy, total operation time, total number of fluoroscopy, amount of bone cement injection, and complication (spinal canal leakage of bone cement) were observed. The visual analogue scale (VAS) and the anterior edge compression rate of the injured vertebra were compared before operation and 3 days after operation between two groups.@*RESULTS@#All 60 patients were successfully operated without complication of spinal canal leakage of bone cement. In the guide plate group, the pedicle puncture time was(10.23±3.15) min and the number of fluoroscopy was(4.77±1.07) times, the total operation time was (33.83±4.21) min, the total number of fluoroscopy was(12.27±2.61) times;and in the conventional group, the pedicle puncture time was (22.83±3.09) min and the number of fluoroscopy was (10.93±1.62) times, the total operation time was(44.33±3.57) min, the total number of fluoroscopy was(19.20±2.67) times. There were statistically significant differences in the pedicle puncture time, intraoperative number of fluoroscopy, the total operation time, and the total number of fluoroscopy between the two groups(P<0.05). There was no significant difference in amount of bone cement injection between the two groups(P>0.05). There were no significant differences in VAS and the anterior edge compression rate of the injured vertebra at 3 days after operation between two groups(P>0.05).@*CONCLUSION@#Three dimensional printing percutaneous guide plate assisted percutaneous kyphoplasty is safe and reliable, which can reduce the number of fluoroscopy, shorten the operation time, and decrease the radiation exposure of patients and medical staff, and conforms to the concept of precise orthopaedic management.

Efficacy of 3D-printed segmental tumor prosthesis for reconstruction of bone defects after resection of weight-bearing long bone tumors in the lower extremity / 中华骨科杂志

Objective:To investigate the efficacy of 3D-printed segmental tumor prosthesis for reconstruction of bone defects after resection of weight-bearing long bone tumors in the lower extremity.Methods:A total of 71 patients who received 3D-printed segmental metal tumor prosthesis for reconstruction of bone defects from August 2015 to August 2021 at the Musculoskeletal Tumor Center of Peking University People's Hospital were retrospectively analyzed. There were 40 males and 31 females, aged 23.08±18.52 years (range, 10-63 years). Tumor types: 49 cases of osteosarcoma, 9 cases of Ewing sarcoma, 3 cases of chondrosarcoma, 3 cases of synovial sarcoma, 2 cases of pleomorphic undifferentiated sarcoma, 2 cases of rhabdomyosarcoma, 2 cases of bone metastasis, and 1 case of low-grade malignant tumor of mesenchymal origin. Ennecking stage of bone tumor: 19 cases of stage III, 52 cases of stage IIb. Tumor location: femur 43 cases, tibia 28 cases. Operative time, intraoperative bleeding, patient survival and postoperative complications were recorded. Kaplan-Meier curves for prosthetic survival were plotted. The osseointegration at the prothesis-bone interface was determined by combination of clinical presentation and imaging. Limb function scores were evaluated using the Musculoskeletal Tumor Society (MSTS) 93 function score.Results:All 71 patients successfully completed the operation and were followed up for 24.4±13.2 months (range, 6.6-65.4 months). At the last follow-up, 50 patients survived without disease, 12 survived with the disease, and the remaining 9 cases died with disease. A total of 11 cases showed prosthesis failure, including 1 case of aseptic loosening, 3 cases of screw breakage or periprosthetic fracture, 1 case of periprosthetic infection, and 6 cases of tumor progression involving the prosthesis. The Kaplan-Meier curve showed that the 1-year, 3-year and 5-year survival rates of prosthesis were 94.2%±2.8%, 86.1%±4.7% and 79.5%±9.2%, respectively. 62 patients received functional follow-up, and the MSTS93 functional score at the last follow-up was 23.95±5.03 points (range, 10-30 points), with an excellent rate of 90% (56/62). The score of femoral prosthesis was 24.63±4.97 points (range, 13-30 points) and the score of tibial prosthesis was 23.29±5.09 points (range, 10-29).Conclusion:3D-printed segmental tumor prosthesis for reconstruction of bone defect after resection of weight-bearing long bone tumors in the lower extremity has a relative high survival rate, a low incidence of prosthetic complications, and a good recovery of function, and it can be used as an option for the postoperative reconstruction of bone tumors in weight-bearing bones of the lower extremity.

The effectiveness of pedicle navigation template with point-contact clamping fixation in complex pedicle of scoliosis / 中华骨科杂志

Objective:To explore the effect of a new 5-point positioning point contact clamping fixation pedicle navigation template in treating cases of scoliosis and complex pedicle.Methods:From February 2019 to February 2023, 30 patients with scoliosis and complicated pedicle were admitted for orthopedic surgery. There were 11 males and 19 females, with an average age of 16.54±6.23 years (range 7 to 35 years). A total 60 cases treated before February 2019 were matched as a control group, including 23 males and 37 females, with an average age of 16.72±6.34 years (range 6 to 35 years). During the operation, the 5-point positioning point-contact clamping fixation pedicle navigation template was used to guide the screws. Screw placement time, screw placement bleeding volume, fluoroscopy frequency, manual redirection frequency, Rao pedicle screw placement classification and accuracy, screw placement complications, and main curve correction rate were recorded.Results:All the 30 cases from the study group successfully underwent the surgery with a total of 354 screws placed, while in the control group a total of 727 screws were placed in 60 cases. The surgery times and intraoperative bleeding volumes for the study group and the control group were 279.45±57.72 min vs. 292.54±58.87 min and 921.57±371.32 ml vs. 932.83±376.65 ml with significant differences ( t=-2.13, P=0.022; t=-1.87, P=0.024). The time for screw placement from the start of skin incision to the placement of the last screw and the bleeding volume during screw placement in the study group and the control group was 82.87±24.46 min vs. 97.53±25.56 min and 72.25±43.66 ml vs. 106.53±61.22 ml with significant differences ( t=-2.66, P=0.031; t=-2.32, P=0.027). The screw placement fluoroscopy frequencies and manual redirection frequencies in the study group and the control group were 4.21±1.11 times vs. 6.32±1.81 times and 0.47±0.64 times vs. 0.93±0.86 times with significant differences ( t=-4.66, P<0.001; t=-2.78, P=0.018). According to the Rao pedicle screw placement classification, the study group had 329 screws classified as level I, 19 screws as level II, and 6 screws as level III. In the control group, there were 669 screws classified as level I, 45 screws as level II, 12 screws as level III, and 1 screw as level IV with no significant difference (χ 2=4.26, P=0.547). The screw placement accuracy and the main curve correction rate in the study group and the study group was 98.31%±3.10% vs. 98.21%±4.92% and 57.85%±9.46% vs. 6.64%±9.22% with no significant differences ( t=0.88, P=0.384; t=0.42, P=0.663). No complications of nerve damage, major vascular injury, cerebrospinal fluid leakage, infection, or death happened during surgery or postoperatively. There were no complications of internal fixation displacement, loosening, or breakage. The outcomes of the patients were good with significantly improved appearance and trunk balance after surgery. Conclusion:The new navigation template provided an accurate and safe way of placing screws in treating various deformities of the lamina articular process without extensive and complete dissection of the posterior structure, leading to reduced fluoroscopy and operation time.

Clinical effects of 3D printed porous titanium-alloy prosthesis in repairing aseptic large bone defects in the limbs / 中华骨科杂志

Objective:To explore the clinical feasibility and effectiveness of using 3D printed porous titanium-alloy prosthesis to repair aseptic large bone defects in the limbs.Methods:A retrospective analysis was performed on 13 patients with aseptic bone defects of long limbs treated with 3D printed porous titanium alloy prosthesis from December 2017 to December 2022, including 7 males and 6 females, aged 52.6±11.5 years (range, 35-72 years). The bone defect locations included 2 humerus, 1 radius, 5 femur, and 6 tibia. One patient suffered both femoral and tibial defects. All 13 patients suffered from bone nonunion due to internal fixation surgery, including 5 cases of hypertrophic nonunion and 8 cases of atrophic nonunion. The interval between internal fixation surgery and this treatment was 20.1±3.6 months (range, 16.5-26.6 months). The clinical treatment effect was evaluated through parameters such as gross observation, imaging evaluation, disability of arm shoulder and hand (DASH), lower extremity functional scale (LEFS), and patient satisfaction evaluation.Results:The length of bone defect after debridement in 13 patients was 11.7±4.5 cm (range, 6.0-20.6 cm), and the length of implant was 12.9±5.3 cm (range, 6.1-22.9 cm). Partial or complete weight-bearing began at 14.8±6.5 days (range, 2-22 days) after surgery. All 13 cases were followed up for 18.3±12.5 months (range, 13-58 months). The X-ray images showed that the prosthesis and the internal fixation were stable, and the new bone gradually grew gradually from the bone defect section and formed stable bone integration with the prosthesis surface, and no prosthesis displacement or fracture occurred. At the last follow-up, the DASH scores of 3 patients with upper limb bone defect were 8.9, 10.5, and 11.2 points, respectively, and the LEFS scores of 10 patients with lower limb bone defect were 49.6±5.9 points (range, 38-56 points). No significant subsidence or loosening of all prosthetics was observed. Patient satisfaction was 9.8±0.1 points (range, 9.6-9.9).Conclusion:After the application of 3D printed porous titanium alloy prosthesis to repair the aseptic large bone defect of the limbs, the patients can carry weight and function exercise in the early stage, and the function of the affected limbs can recover significantly, and the patients have high satisfaction.

Effect of 3D-printed nano-β-tricalcium phosphate in repairing seawater-soaked tibial defects in rabbits / 中华创伤杂志

Objective:To explore the repairing effects of 3D-printed nano-β-tricalcium phosphate (β-TCP) scaffolds loaded with vancomycin and bone morphogenetic protein-2 (BMP-2) for seawater -soaked tibial bone defects in rabbits. Methods:A total of 27 male New Zealand White rabbits were assigned to the normal group using a random number table method, with each group consisting of 9 rabbits. The rabbit tibial bone defect model was created using the osteotomy surgical method. Eight hours after operation, the wounds in the control group and seawater group were immersed in seawater for 2 hours, and those in the normal group were not immersed. After an observation period of 5-7 days, no significant redness or purulent discharge was observed in the wound appearance, then debridement was performed followed by corresponding implantations: the control group with gelatin sponges loaded with vancomycin and BMP-2, and the other two groups with 3D-printed nano-β-TCP scaffolds loaded with vancomycin and BMP-2. After filling the bone defects with the respective materials, all groups underwent layer-by-layer suturing of the wound, followed by disinfection with iodine and injection of gentamicin to prevent infection. The affected limbs were then immobilized using a plaster cast. The affected limbs were imaged using anteroposterior X-ray at 4, 8 and 16 weeks after operation, and the repair effects were evaluated using the Lane-Sandhu X-ray scoring system. At 16 weeks after operation, the bone defect tissues were collected for HE staining to observe bone tissue growth.Results:At 4 weeks after operation, the Lane-Sandhu X-ray score in the control group was significantly lower than that in the normal group [(2.8±1.1)points vs. (1.1±0.9)points] ( P<0.05), and that in the seawater group [(2.2±1.0)points] was not significantly different from those in the other two groups (all P>0.05). At 8 weeks after operation, the seawater group [(6.1±0.9)points] and the control group [(2.8±1.0)points] exhibited lower Lane-Sandhu X-ray score compared to the normal group [(8.2±1.0)points] (all P<0.05), and the seawater group showed a higher score compared to the control group ( P<0.05). At 16 weeks after operation, the control group [(3.8±1.0)points] exhibited a lower Lane-Sandhu X-ray score compared to the normal group [(10.0±1.3)points] and the seawater group [(9.3±1.2)points] (all P<0.05), while no significant difference was noted between the latter two ( P>0.05). At 16 weeks after operation, histological observations revealed varying degrees of bone tissue formation in three groups, with the normal group showing the best bone defect repair effect, followed by the seawater group. Conclusion:The 3D-printed nano-β-TCP scaffolds loaded with vancomycin and BMP-2 are effective for the treatment of seawater -soaked bone defects, which can promote bone tissue repair.