Dosimetric effect of customized 3D-printed headrest in radiotherapy for head and neck tumor / 中国医学物理学杂志

Objective To evaluate the dosimetric effect of three-dimensional(3D)printed headrests made of different materials in radiotherapy for head and neck tumor,and to evaluate whether the existence of customized 3D-printed headrest can be neglected during planning phase by comparing differences in target area doses,homogeneity index(HI),conformity index(CI),monitor units(MU),and organ-at-risk(OAR)dose.Methods Ten patients with head and neck tumors,including 5 cases with nasopharyngeal carcinoma and 5 with other head and neck tumors,were enrolled.The headrest contours were outlined using Monaco treatment planning system,and with the same calculation parameters,treatment plans were generated for scenarios without a headrest,with a standard headrest,and with 3D-printed headrests made of 10%filled polylactic acid and thermoplastic polyurethane.The target area doses,OAR dose,MU,and other results were recorded and subjected to statistical analysis.Results No significant differences were observed among the 4 groups(ignoring headrest,standard headrest,3D-printed headrests with 10%filled polylactic acid and thermoplastic polyurethane)in parameters such as D95,D5,Dmean,HI,CI,MU,and OAR dose(the maximum dose to the spinal cord)(P>0.05).Considering the presence of the headrest,significant differences were found in CI for nasopharyngeal carcinoma and other head and neck tumors(P<0.05).Conclusion During the planning phase,the existence of customized 3D-printed headrest can be ignored,but it should be noted that the presence of a headrest may reduce the MU in radiotherapy plans.When considering the headrest,the average CI of patients with other head and neck tumors is significantly higher than that with nasopharyngeal carcinoma.

Reliability of a region-locked 3D-printed template combined with a bi-directional matching scheme to assist screw placement for thoracolumbar fractures / 中华创伤骨科杂志

Objective:To evaluate the reliability of a region-locked 3D-printed template combined with a bi-directional matching scheme in assistance of screw placement for thoracolumbar fractures.Methods:From January 2019 to March 2023, 52 patients with thoracolumbar fracture were treated at Department of Orthopedics, The People's Hospital of Liyang. They were 29 males and 23 females, with an age of (58.2±13.3) years. They were divided into a template group and a free-hand group according to the different screw placements. In the template group of 25 cases, a region-locked 3D-printed template combined with a bi-directional matching scheme was used to assist the pedicle positioning; in the free-hand group of 27 cases, the free hand screw placement was assisted only by image data and C-arm fluoroscopy. The operation time, intraoperative fluoroscopy frequency, intraoperative blood loss, complications, and placement accuracy were compared between the 2 groups. Visual analogue scale (VAS), Oswestry disability index (ODI), and anterior height ratio of the injured vertebra were compared between preoperation, 1 week postoperation, and the final follow-up, as well as between the 2 groups.Results:There were no statistically significant differences in the preoperative general data between the 2 groups, showing comparability ( P>0.05). All patients were followed up for (11.2±4.2) months. The differences were not statistically significant between the 2 groups in intraoperative blood loss, rate of complications, VAS or ODI at preoperation, 1 week postoperation, or the final follow-up, or in anterior height ratio of the injured vertebra ( P>0.05). In the template group, the operation time [(80.1±18.5) min] was significantly longer than that in the free-hand group [(69.4±16.6) min], the intraoperative fluoroscopy frequency [2 (2, 3) times] significantly lower than that in the free-hand group [3 (3, 4) times], and the placement accuracy [98.4% (127/129)] significantly higher than that in the free-hand group [91.8% (112/122)] (all P<0.05). All patients showed significant improvements in VAS, ODI and anterior height ratio of the injured vertebra at postoperative 1 week compared with the preoperative values, and the improvements at the last follow-up were significantly larger than those at postoperative 1 week ( P<0.05). No injury to the spinal cord, nerve root or blood vessel was observed postoperatively. Conclusions:In the treatment of thoracolumbar fractures, the screw placement assisted by a region-locked 3D-printed template combined with a bi-directional matching scheme is better than free-hand screw placement in terms of improved accuracy and reduced fluoroscopy, but the former incurs longer operative exposure than the latter. There is no significant difference between the 2 methods of screw placement in clinical efficacy.

Three-dimensional Printing of Inertial Microchannel with Complex Cross-section and Characterization of Particle Inertial Focusing / 分析化学

Projection micro stereolithography three-dimensional(3D)printing method was proposed in this study to fabricate complex microchannels of combined cross-sections.By using 3D printing and polydimethylsiloxane(PDMS)replication methods,two inertial microfluidic chips of three-step and five-step cross-sections were fabricated,and the dimension precisions of the microchannels were controlled within 20 μm.Using the microfluidic chips,the movements of two fluorescent polystyrene particles with diameters of 10 and 6 μm in the stepped channels were investigated.In addition,numerical simulations were applied to demonstrate the inertial focusing mechanisms of particles in the channels.It was found that 10-μm particles had three equilibrium positions in the three-step channel,which located at the inner walls of the three steps,respectively,and most particles focused at the inner step.The 6-μm particles also had three equilibrium positions in the three-step channel.However,the particles migrated to the middle and the outer steps under high flow rates.In the five-step channel,when the flow rate was increased gradually,10-μm particles had a single and two equilibrium positions,respectively,and the particles migrated towards the inner channel wall under high flow rates.In comparison to 10-μm particles,6-μm particles had two stable equilibrium positions in the five-step channel at all flow rate range.It could be concluded that the quantity,shape and strength of the secondary flow vortex could be altered by changing structure of the combined cross-section,thus the equilibrium positions and quantities of the focusing particles could be also regulated.The research outcome might provide new insights for precise cell inertial manipulation and promote the application and development of inertial microfluidic technology in biomedical and other fields.

Visualization of nasal powder distribution using biomimetic human nasal cavity model

Nasal drug delivery efficiency is highly dependent on the position in which the drug is deposited in the nasal cavity. However, no reliable method is currently available to assess its impact on delivery performance. In this study, a biomimetic nasal model based on three-dimensional (3D) reconstruction and three-dimensional printing (3DP) technology was developed for visualizing the deposition of drug powders in the nasal cavity. The results showed significant differences in cavity area and volume and powder distribution in the anterior part of the biomimetic nasal model of Chinese males and females. The nasal cavity model was modified with dimethicone and validated to be suitable for the deposition test. The experimental device produced the most satisfactory results with five spray times. Furthermore, particle sizes and spray angles were found to significantly affect the experimental device's performance and alter drug distribution, respectively. Additionally, mometasone furoate (MF) nasal spray (NS) distribution patterns were investigated in a goat nasal cavity model and three male goat noses, confirming the in vitro and in vivo correlation. In conclusion, the developed human nasal structure biomimetic device has the potential to be a valuable tool for assessing nasal drug delivery system deposition and distribution.

Multi-criteria decision model in treatment of adolescent scoliosis with three-dimensional printed scoliosis orthosis / 中国组织工程研究

BACKGROUND:Traditional scoliosis orthosis has some disadvantages,such as complex manufacturing process,long processing cycle,poor fit and so on.Three-dimensional printed scoliosis orthosis has the advantages of high manufacturing precision and personalization. OBJECTIVE:To evaluate the efficacy of three-dimensional printed scoliosis orthosis for scoliosis based on multi-criteria decision model. METHODS:Clinical data of 72 patients with scoliosis admitted to Chen Xinghai Hospital of Integrated Traditional Chinese and Western Medicine from January 2019 to October 2022 were retrospectively collected and divided into two groups according to the treatment of orthosis.Study group(n=23)received three-dimensional printed scoliosis orthosis.Traditional group(n=49)received the traditional polypropylene spine brace treatment.The clinical efficacy and complications were compared between the two groups.A multi-criteria decision model for the treatment of scoliosis with three-dimensional printed scoliosis orthosis was established,and the stability of the benefit value,risk value and decision model of the two groups were evaluated. RESULTS AND CONCLUSION:(1)Compared with the traditional group,there were significant differences in the top vertebral offset distance,Cobb angle,top vertebral rotation,Functional Movement Screen score,visual analog scale score and total effective rate in the study group at 6 months after surgery(P<0.05).(2)Among the benefit indexes,Cobb angle had the greatest impact on the condition of patients,while the risk indexes had the greatest impact on dyspnea.(3)The benefit values of the study group and the traditional group for scoliosis were 79 and 64,and the risk values were 74 and 57,respectively.The combined benefit and risk values found that the benefit-risk value of the study group was 16 higher than that of the traditional group.(4)In the range of 0-100%relative risk weight,the benefit-risk value of the study group was always higher than that of the traditional group,which proved that the multi-criteria decision-making model had good stability.(5)It is indicated that three-dimensional printed scoliosis orthosis can better restore the physiological curvature of scoliosis and improve the efficiency of treatment.

Solutions based on three-dimensional technologies for the practice and teaching of biomedical sciences

Introduction: Three-dimensional printing is one of the technologies that promote change at an economic and social level, and one of the fundamental elements of industry 4.0. It has enormous potential for the future of medicine, establishing itself as a new paradigm. Despite its advantages, its use in our environment is incipient. Objective: To design and develop solutions based on three-dimensional technologies for the teaching and practice of biomedical sciences. Materials and methods: A technological development investigation was carried out between the Center for Assisted and Sustainable Manufacturing of the University of Matanzas and Matanzas University of Medical Sciences, between September 2019 and July 2022. The designs and fabrications were made from the acquisition of computed tomography images, or from a surface scanner, which were then processed, converted into Standard Tessellation Language format, printed, and post-processed. Virtual designs were developed using computer-aided design software. Results: Various solutions were developed including prototypes: biomodels for craniosynostosis repair and anatomical figures, custom cranial prosthesis mold, hand prosthesis, O2 line splitters, tissue scaffolds, syringe gun, face shields, breast prosthesis; autologous restoration mold and tissue expander. Conclusions: In all areas of application of this technology in medicine―except the printing of medicines, in the current context―, it is feasible to obtain solutions in the territory of Matanzas. It is therefore imperative that managers and the medical community in general, begin to acquire awareness, knowledge, and experience to ensure the optimal use of this technology.

Introducción: La impresión tridimensional es una de las tecnologías que promueve el cambio a nivel económico y social, y uno de los elementos fundamentales de la industria 4.0. Asimismo, constituye un enorme potencial para el futuro de la medicina, estableciéndose como un nuevo paradigma. A pesar de sus ventajas, su explotación en nuestro medio es incipiente. Objetivos: Diseñar y desarrollar soluciones basadas en tecnologías tridimensionales para la enseñanza y la práctica de las ciencias biomédicas. Materiales y métodos: Se realizó una investigación colaborativa, de desarrollo tecnológico entre el Centro de Fabricación Asistida y Sostenible de la Universidad de Matanzas y la Universidad de Ciencias Médicas de Matanzas, entre septiembre de 2019 y julio de 2022. Los diseños y fabricaciones se realizaron a partir de la adquisición de imágenes de tomografía computarizada, o desde un escáner de superficie, las que luego se procesaron, se convirtieron en formato Standard Tessellation Language, se imprimieron y posprocesaron. Los diseños virtuales se desarrollaron empleando un software de diseño asistido por computadora. Resultados: Se desarrollaron varias soluciones que incluyen varios prototipos: biomodelos para reparación de craneosinostosis y figuras anatómicas, molde de prótesis craneal personalizada, prótesis de mano, divisores de líneas de O2, andamios tisulares, pistola portajeringas, protectores faciales, prótesis de mama, molde para restauración autóloga y expansor tisular. Conclusiones: En todas las áreas de aplicación de esta tecnología en medicina―salvo en la impresión de medicamentos, en el contexto actual―, es factible obtener soluciones en el territorio de Matanzas. Es un imperativo, pues, que directivos y la comunidad médica en general, comiencen a adquirir conciencia, conocimientos y experiencias para garantizar la utilización óptima de esta tecnología.

Evaluation of surface roughness, wettability and adhesion of multispecies biofilm on 3D-printed resins for the base and teeth of complete dentures

Abstract Studies evaluating the roughness, wettability and microbial adhesion of 3D-printed resins for complete denture bases and teeth are scarce. Objective This study evaluated the surface roughness, wettability and adhesion of multispecies biofilms (Candida albicans, Staphylococcus aureus and Streptococcus mutans) on 3D-printed resins for complete denture bases and teeth compared to conventional resins (heat-polymerized acrylic resin; artificial pre-fabricated teeth). Methodology Circular specimens (n=39; 6.0 mm Ø × 2.0 mm) of each group were subjected to roughness (n=30), wettability (n=30) and biofilm adhesion (n=9) tests. Three roughness measurements were taken by laser confocal microscopy and a mean value was calculated. Wettability was evaluated by the contact angle of sessile drop method, considering the mean of the three evaluations per specimen. In parallel, microorganism adhesion to resin surfaces was evaluated using a multispecies biofilm model. Microbial load was evaluated by determining the number of Colony Forming Units (CFU/mL) and by scanning electron microscopy (SEM). Data were subjected to the Wald test in a generalized linear model with multiple comparisons and Bonferroni adjustment, as well as two-way ANOVA (α=5%). Results The roughness of the conventional base resin (0.01±0.04) was lower than that of the conventional tooth (0.14±0.04) (p=0.023) and 3D-printed base (0.18±0.08) (p<0.001). For wettability, conventional resin (84.20±5.57) showed a higher contact angle than the 3D-printed resin (60.58±6.18) (p<0.001). Higher microbial loads of S. mutans (p=0.023) and S. aureus (p=0.010) were observed on the surface of the conventional resin (S. mutans: 5.48±1.55; S. aureus: 7.01±0.57) compared to the 3D-printed resin (S. mutans: 4.11±1.96; S. aureus: 6.42±0.78). The adhesion of C. albicans was not affected by surface characteristics. The conventional base resin showed less roughness than the conventional dental resin and the printed base resin. Conclusion The 3D-printed resins for base and tooth showed less hydrophobicity and less adhesion of S. mutans and S. aureus than conventional resins.

Impressão 3D na relação médico-paciente, relato de experiência da integração entre ensino, inovação e assistência / 3D printing in the physician-patient relationship, experience report on the integration between education, innovation and care

RESUMO Introdução: Na literatura, diversos artigos apresentam a satisfação dos pacientes e a melhor clareza de entendimento acerca das informações transmitidas pela equipe médica, com o auxílio de peças tridimensionais. A educação e a saúde são práticas inseparáveis e interdependentes, sempre estiveram articuladas, consideradas elementos fundamentais no processo de atuação dos profissionais da saúde. Assim, professores e alunos do curso de Medicina da Universidade Federal de Pernambuco criaram uma extensão universitária, que objetivava o uso de modelos anatômicos, impressos em 3D, para educação dos pacientes do ambulatório de ortopedia e traumatologia. Relato de experiência: Ao longo dos seis meses de projeto, foram assistidos 77 pacientes, e o projeto contou com o trabalho de três professores e 18 alunos da graduação, totalizando 98 pessoas envolvidas no projeto. As ações foram divididas em dois blocos. O primeiro consistiu na capacitação dos alunos. No segundo, os discentes realizavam visitas ao ambulatório, acompanhados por um médico especialista responsável, usavam peças impressas pelos próprios alunos, para orientar os pacientes quanto à sua respectiva condição, e davam orientações sobre a terapêutica valendo-se dessas peças impressas. Discussão: A possibilidade de utilização dessa ferramenta como auxílio na comunicação médica abre um vasto horizonte de aplicação da impressão 3D na educação popular em saúde. Isso, por sua vez, propicia o aperfeiçoamento da promoção da saúde de regiões menos desenvolvidas, uma vez que essa interação entre equipe de saúde e comunidade permite a promoção, a proteção e a recuperação da saúde, a partir de um diálogo horizontal, valorizando e respeitando o usuário do sistema de saúde, de maneira a torná-lo agente e protagonista do processo saúde e doença. Conclusão: Projetos de extensão desse tipo têm um enorme potencial para gerar impactos na medicina, na comunidade acadêmica e na população assistida, sobretudo a menos instruída.

ABSTRACT Introduction: In the literature, several articles demonstrate patient satisfaction and better understanding of the information transmitted by the medical team, with the aid of three-dimensional pieces. Education and health are inseparable and interdependent practices, they have always been articulated, and considered crucial elements in the action process of health professionals. Thus, teachers and students of the medicine course at Universidade Federal de Pernambuco created a university extension project that aimed at the use of anatomical models printed in 3D, for the education of patients in the orthopedics and traumatology outpatient clinic. Experience Report: Over the six months of the project, 77 patients were assisted and the project employed the work of 3 teachers and 18 undergraduate students, totaling 98 people involved in the project. The actions were divided into 2 blocks: the first consisted of training the students and, in the second, the students visited the outpatient clinic, accompanied by a specialist physician in charge and used pieces printed by the students themselves, to guide the patients regarding their respective condition and provided guidance on therapy using these printed pieces. Discussion: the possibility of using this tool as an aid in medical communication opens up a vast horizon of application of 3D printing in health education. This, in turn, favors the improvement of health promotion in less developed regions, since this interaction between the health team and the community allows the promotion, protection and recovery of health, based on a horizontal dialogue, valuing and respecting the users of the health system, aiming to make them an agent and protagonist of the health and disease process. Conclusion: It can be concluded, therefore, that extension projects such as this one have enormous potential to generate impacts on medicine, the academic community and the assisted population, especially the less educated ones.

Desafíos en el empleo de los medicamentos huérfanos

Las enfermedades raras son aquellas que tienen baja prevalencia y que, por lo tanto, el desarrollo de medicamentos para tratarlas no es rentable para las empresas farmacéuticas debido a la baja demanda. A pesar de que ya se cuenta con diferentes políticas públicas alrededor del mundo para incentivar a las industrias farmacéuticas a investigar estos medicamentos, conocidos como medicamentos huérfanos, su desarrollo conlleva muchas dificultades en las evaluaciones clínicas y el precio final para el público es muy elevado. Si bien en años recientes se ha planteado el uso de tecnología de impresión en 3D para producir estos medicamentos o incluso recurrir a otros medicamentos previamente aprobados para tratar enfermedades raras, existe un historial de mal uso de las legislaciones por parte de las empresas con el fin de generar beneficios comerciales, por lo que estas políticas deben reforzarse para que cumplan su propósito; ayudar a una población muy vulnerable. El objetivo del presente texto es exponer los resultados de una revisión documental sobre el panorama científico y sociopolítico en el que se encuentra el problema de las enfermedades raras y los medicamentos huérfanos, así como las posibles soluciones que se están desplegando para abordarlo. Deriva de un estudio que se desarrolla en el momento actual en la Universidad Autónoma Metropolitana, de Ciudad de México.

The strange illnesses are those that have low prevalence and that, therefore, the development of medications to treat them is not profitable for the pharmaceutical companies due to the drop demands. Although it is already counted with different political public around the world to motivate to the pharmaceutical industries to investigate these medications, well-known as orphan medications, their development bears many difficulties in the clinical evaluations and the final price for the public it is very high. Although in recent years he/she has thought about the use of impression technology in 3D to produce these medications or even to appeal to other medications previously approved to treat strange illnesses, a record of wrong use of the legislations exists on the part of the companies with the purpose of generating commercial benefits, for what these politicians should be reinforced so that they complete its purpose; to help a very vulnerable population. The objective of the present text is to expose the results of a documental revision on the scientific and sociopolitical panorama in which is the problem of the strange illnesses and the orphan medications, as well as the possible solutions that they are spreading to approach it. It derives of a study that is developed in the current moment in the Metropolitan Autonomous University, of Mexico City.

Application and Progress of Digital Navigation Technology in Micro-apical Surgery / 中国医疗器械杂志

As imaging technology develops rapidly, dynamic and static guided technology is widely used in many medical fields now. In order to improve the success rate, reduce surgical complications and improve future prognosis, domestic and foreign experts have introduced digital navigation technology into apical surgery. With the help of digital navigation technology, apical lesions can be easily located and the scope of osteotomy can be limited, which can make the surgery be completed accurately, especially in complex clinical cases. This study overviews the clinical use and research progress of dynamic and static guided technology in apical surgery, summarizes the advantages and disadvantages of this technique as well as looks forward to its future.

Three-dimensional printed 316L stainless steel cardiovascular stent's electrolytic polishing and its mechanical properties / 生物医学工程学杂志

The interventional therapy of vascular stent implantation is a popular treatment method for cardiovascular stenosis and blockage. However, traditional stent manufacturing methods such as laser cutting are complex and cannot easily manufacture complex structures such as bifurcated stents, while three-dimensional (3D) printing technology provides a new method for manufacturing stents with complex structure and personalized designs. In this paper, a cardiovascular stent was designed, and printed using selective laser melting technology and 316L stainless steel powder of 0-10 µm size. Electrolytic polishing was performed to improve the surface quality of the printed vascular stent, and the expansion behavior of the polished stent was assessed by balloon inflation. The results showed that the newly designed cardiovascular stent could be manufactured by 3D printing technology. Electrolytic polishing removed the attached powder and reduced the surface roughness Ra from 1.36 µm to 0.82 µm. The axial shortening rate of the polished bracket was 4.23% when the outside diameter was expanded from 2.42 mm to 3.63 mm under the pressure of the balloon, and the radial rebound rate was 2.48% after unloading. The radial force of polished stent was 8.32 N. The 3D printed vascular stent can remove the surface powder through electrolytic polishing to improve the surface quality, and show good dilatation performance and radial support performance, which provides a reference for the practical application of 3D printed vascular stent.

Application of a new point contact pedicle navigation template as an auxiliary screw implant in scoliosis correction surgery / 中国修复重建外科杂志

OBJECTIVE@#To explore the effectiveness of a new point contact pedicle navigation template (referred to as "new navigation template" for simplicity) in assisting screw implantation in scoliosis correction surgery.@*METHODS@#Twenty-five patients with scoliosis, who met the selection criteria between February 2020 and February 2023, were selected as the trial group. During the scoliosis correction surgery, the three-dimensional printed new navigation template was used to assist in screw implantation. Fifty patients who had undergone screw implantation with traditional free-hand implantation technique between February 2019 and February 2023 were matched according to the inclusion and exclusion criteria as the control group. There was no significant difference between the two groups ( P>0.05) in terms of gender, age, disease duration, Cobb angle on the coronal plane of the main curve, Cobb angle at the Bending position of the main curve, the position of the apical vertebrae of the main curve, and the number of vertebrae with the pedicle diameter lower than 50%/75% of the national average, and the number of patients whose apical vertebrae rotation exceeded 40°. The number of fused vertebrae, the number of pedicle screws, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were compared between the two groups. The occurrence of implant complications was observed. Based on the X-ray films at 2 weeks after operation, the pedicle screw grading was recorded, the accuracy of the implant and the main curvature correction rate were calculated.@*RESULTS@#Both groups successfully completed the surgeries. Among them, the trial group implanted 267 screws and fused 177 vertebrae; the control group implanted 523 screws and fused 358 vertebrae. There was no significant difference between the two groups ( P>0.05) in terms of the number of fused vertebrae, the number of pedicle screws, the pedicle screw grading and accuracy, and the main curvature correction rate. However, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were significantly lower in trial group than in control group ( P<0.05). There was no complications related to screws implantation during or after operation in the two groups.@*CONCLUSION@#The new navigation template is suitable for all kinds of deformed vertebral lamina and articular process, which not only improves the accuracy of screw implantation, but also reduces the difficulty of operation, shortens the operation time, and reduces intraoperative bleeding.

Application of three-dimensional printed guiding device for electrode implantation in sacral neuromodulation in children / 现代泌尿外科杂志

【Objective】 To investigate the application value of three-dimensional printed guiding device in sacral neuromodulation in children. 【Methods】 A total of 17 patients admitted during Jan.2017 and Nov.2022 were divided into two groups: control group (n=8), using traditional method to locate sacral foramen for puncture; three-dimensional printed guiding device group (n=5), using three-dimensional printing technology to make individual guiding device for puncture. The clinical indexes of the two groups were evaluated, including puncture time, puncture numbers, intraoperative X-ray exposure times, postoperative evaluation time and second-stage conversion rate. The evaluation indexes of postoperative complications were wound bleeding, wound infection, wound rupture, electrode fracture, displacement or prolapse. 【Results】 In the control group, 1 case was diagnosed as bladder-bowel dysfunction, the remaining 7 were neurogenic bladder; in the three-dimensional printed guiding device group, all 9 cases were diagnosed as neurogenic bladder. The puncture time was shorter in the three-dimensional printed guiding device group than in the control group [85(70-90) min vs.138(133-208) min], the puncture numbers were fewer [15(12-20) vs.22(18-26)], and the X-ray exposure times were fewer [12(12-17) vs.19(16-23)] (all P<0.05). The initial stimulation voltage, postoperative evaluation time and second-stage conversion rate were not statistically significant. 【Conclusion】 Compared with the traditional method, the use of three-dimensional printed guiding device can reduce the puncture numbers and shorten the puncture time in the process of sacral neuromodulation in children.

3D-printed navigation template-assisted and freehand posterior cervical screw fixation of atlantoaxial fracture: a comparison of efficacies / 中华创伤杂志

Objective:To compare the efficacies of 3D-printed navigation template assisted and freehand posterior cervical screw fixation of atlantoaxial fractures.Methods:A retrospective cohort study was used to analyze the clinical data of 22 patients with atlantoaxial fractures admitted to Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from September 2018 to December 2020. There were 13 males and 9 females, with age range of 26-68 years [(50.7±11.9)years]. All the patients underwent posterior atlantoaxial pedicle screw internal fixation and fusion, among whom 11 patients admitted from November 2019 to December 2020 were assisted with 3D printed navigation templates for the placement of pedicle screws (assisted group) and 11 patients admitted from September 2018 to October 2019 used the traditional way of placing pedicle screws (freehand group). A total of 88 pedicle screws were implanted, with 44 pedicle screws in each group. The operation time, intraoperative blood loss, and intraoperative fluoroscopy frequency were compared between the two groups. The visual analogue score (VAS) and Japanese Orthopedic Society (JOA) score were also compared before operation, at 3 days, 3 months, 6 months postoperatively and at the last follow-up. The accuracy of pedicle screw placement was evaluated according to the Kawaguchi classification, and complications were observed.Results:All the patients were followed up for 24-30 months [(26.4±1.8)months]. The assisted group showed the operation time of (87.3±19.5)minutes and the intraoperative fluoroscopy frequency of (6.4±1.4)times, decreased compared with the freehand group [(115.5±23.0)minutes, (10.3±1.7)times] [(all P<0.01). However, no significant difference was observed in the intraoperative blood loss between the two groups ( P>0.05). Both groups demonstrated comparable VAS and JOA score before operation, at 3 days, 3 months, 6 months postoperatively and at the last follow-up (all P>0.05). Furthermore, the assisted group exhibited a significantly higher accuracy of pedicle screw placement [95.5% (42/44)] compared with the freehand group [79.5% (35/44)] ( P<0.05). Notably, there were no intraoperative vertebral artery injury, spinal cord injury, or cerebrospinal fluid leakage in either group, or internal fixation loosening, fracture, nonunion in either group after operation. Conclusion:Compared with freehand posterior cervical screw placement, 3D-printed navigation template-assisted posterior cervical pedicle screw fixation of atlantoaxial fracture can shorten the operation time, reduce the intraoperative fluoroscopy frequency, and improve the accuracy of screw placement.

Efficacy comparison between iliosacral screw fixation of the posterior pelvic ring fracture with the assistance of modified percutaneous three-dimensional printing guide template and conventional fluoroscopy / 中南大学学报(医学版)

Objective:The effect of three-dimensional(3D)printed bone-attached guide plate assisted cannulated screw fixation of pelvic fracture is reliable,but extensive soft tissue dissection is still required when installing the guide plate.This study aims to compare the efficacy of posterior pelvic ring fracture fixation with iliosacral screw insertion between the assistance of modified percutaneous patient specific 3D printed guide template and conventional fluoroscopy. Methods:From May,2019 and September 2021,28 patients sustained posterior pelvic ring fractures were randomized into 2 groups:A guide template group,in which the iliosacral screw was inserted for fixation of the posterior pelvic ring fracture with the assistance of modified percutaneous patient specific 3D printed guide template,and a fluoroscopy group,in which the iliosacral screw was inserted under the guidance of conventional fluoroscopy.The operation time,fluoroscopic frequency,intraoperative blood loss,and incision length were recorded for each screw insertion.Fracture reduction was evaluated according to the Matta criteria.The screw position was evaluated according to the modified Gras classification,and the functional outcome was evaluated according to Majeed score.The parameters of both groups were compared,and statistical analysis was performed. Results:All the 28 patients were followed up for 12-24 months.Of them,15 iliosacral screws were inserted in 14 patients in the guide template group,and 14 iliosacral screws were inserted in 14 patients in the fluoroscopy group.The operation time,fluoroscopic frequency,screw deviation,incision length,and blood loss in the guide template group were 20-30(25.8±2.8)min,9-15(12.2±1.9),2-4(2.6±0.7)mm,4-5(4.6±0.5)cm,and 5-10(7.8±1.7)mL,respectively,whereas those in the fluoroscopy group were 30-60(48.1±7.5)min,40-96(64.7±16.3),3-6(4.2±0.9)mm,0.8-1.2(1.0±0.1)cm,and 2-5(3.1±1.3)mL,respectively,and there were statistical significance(all P<0.001).Fracture reduction was evaluated according to the Matta criteria,and all the patients reached excellence and good(P=0.584)in the 2 groups.According to modified Gras classification,there were 12 Grade Ⅰ screws,3 Grade Ⅱ screws,and 0 Grade Ⅲ screws in the guide template group,and 10 Grade Ⅰ screws,3 Grade Ⅱ screws,and 1 Grade Ⅲ screw in the fluoroscopy group,with no statistical significance(P=0.334).The functional outcome was evaluated according to Majeed score at the last follow-up,without significant difference between the guide template group and the fluoroscopy group(P=0.908). Conclusion:Compared with the conventional fluoroscopy,it would cost less operation time,less fluoroscopic frequency and increase more accurate screw insertion to fixate the posterior pelvic ring fracture with the assistance of modified percutaneous patient specific 3D printed guide template.

Efficacy of second-stage Masquelet technique with 3D-printed quantitative bone implants for the treatment of long-segment bone defect following Gustilo type IIIB and IIIC tibial fractures / 中华创伤杂志

Objective:To investigate the efficacy of 3D-printed quantitative bone implants assisting second-stage Masquelet technique for the treatment of long-segment bone defect following Gustilo type IIIB and IIIC tibial fractures.Methods:A retrospective case series analysis was made on 26 patients with long-segment bone defect following Gustilo type IIIB and IIIC tibial fractures treated in Wuxi Ninth People′s Hospital from July 2015 to December 2020, including 20 males and 6 females; aged 19-63 years [(46.5±4.5)years]. Gustilo classification was type IIIB in 23 patients and type IIIC in 3. In the first stage, all patients had thoroughly emergent debridement, removal of all free bone pieces, restoration of the length and force line plus externally fixion, and vacuum sealing drainage (VSD) of the residual wound. After 2-7 days, the external fixation was removed and replaced by internal fixation, with the bone cement filling in the defect area and the free flap covering the wound. The length of tibial bone defect was 5-14 cm [(6.3±0.4)cm], and the tibial defect volume was 12.2-73.1 cm 3 [(33.6±9.2)cm 3]. In the second stage (6-19 weeks after injury), the bone cement was removed, followed by autologous bone grafting. Prior to bone grafting, digital technology was used to accurately calculate the bone defect volume, and an equal volume of bone harvesting area was designe to produce the 3D printed osteotomy template. Bone grafting was conducted after bone removal according to the osteotomy template during operation. The success rate of one-time iliac bone extraction, bone harvesting time, and bleeding volume were recorded. Pain in the bone extraction area was evaluated by visual analogue score (VAS) at 1 day and 1 month after operation and at the last follow-up. Wound healing, complications, and bone healing were observed. Life quality was evaluated by health survey brief form (SF-36) including scores of physical component summary (PCS) and mental component summary (MCS) before bone grafting and at the last follow-up. Results:All the patients were followed up for 13-53 months [(32.3±12.5)months]. One-time iliac bone extraction was successful in all the patients. Bone harvesting time was 15-30 minutes [(21.0±2.5)minutes]. The bleeding volume was 50-120 ml [(62.3±29.0)ml]. The VAS was 1-4 points [(1.2±0.9)points] at 1 day after operation, higher than these (0.0±0.0)points at 1 month after operation and at the last follow-up (all P<0.01). Totally, 25 patients obtained wound healing after operation, except for 1 patient with superficial wound infection after bone grafting that was healed by dressing change. There was 1 patient with bone infection after 3 months of bone grafting that was healed by repeated surgery with Masquelet technique in the first and second stage. Besides, 2 patients had symptoms of cutaneous nerve injury in the iliac donor area. The time of bone healing was 4-7 months [(5.8±0.8)months]. The scores of PCS and MCS in SF-36 at the last follow-up were (73.6±12.8)points and (83.6±13.2)points, significantly higher than those before bone grafting [(46.8±0.5)points, (60.7±2.0)points] (all P<0.01). Conclusion:Second-stage Masquelet technique with 3D printed quantitative bone implants for the treatment of long-segment bone defect following Gustilo type IIIB and IIIC tibial fractures is associated with shortened bone harvesting time, attenuated pain, reduced complications, accelerated bone healing and improved function.

Application of three dimensional bio-printing materials for tissue engineering tracheal grafting / 中华器官移植杂志

Currently three dimensional bio-printing technology has become one of the hot topics for tissue engineering tracheal grafting.Different biomaterials have their own performance advantages in the preparation and regeneration of tracheal scaffolds.It is particularly imperative to seek natural or polymeric materials with excellent profiles of printability, structural stability and biocompatibility to enable neo-cartilage formation, neo-epithelialization and neo-vascularization of tissue engineering trachea grafting.This review summarized the shortcomings and challenges of classifying and applying materials for three dimensional bio-printing tissue engineering trachea, aiming to provide new rationales for researches and applications of tissue engineering tracheal grafting.

Totally endoscopic transmitral septal myectomy for the treatment of recurrent left ventricular outflow tract obstruction after alcohol septal ablation / 中国胸心血管外科临床杂志

@#Objective    To investigate the surgical strategies and clinical efficacy of transmitral septal myectomy in the treatment of recurrent left ventricular outflow tract obstruction (LVOTO) after alcohol septal ablation. Methods    The clinical data of patients with recurrent LVOTO after alcohol septal ablation from July 2020 to July 2021 in the Department of Cardiac Surgery, Guangdong Provincial People's Hospital were retrospectively analyzed. Patients were preoperatively evaluated by echocardiography, cardiac magnetic resonance imaging, cardiac computed tomography, 3D modeling and printing technology. A personalized surgical strategy was preoperatively developed according to multimodality imaging assessment, while visual exploration was performed on the digital model and simulated surgical resection was performed on the printed model. Results     Two female patients were enrolled, aged 62 years and 64 years, respectively. Totally endoscopic transmitral extended myectomy was successfully performed on both patients with aortic cross-clamping time of 96 min and 85 min, respectively. LVOTO was relieved immediately (subaortic peak pressure gradient decreased from 100 mm Hg to 4 mm Hg and from 84 mm Hg to 6 mm Hg, respectively) and the mitral regurgitation significantly improved after the procedure. No patient had complete atrioventricular block or required permanent pacemaker implantation. The patients were discharged uneventfully without postoperative complications. Conclusion    Personalized totally endoscopic transmitral extended myectomy combined with multimodality imaging assessment and 3D modeling and printing has an acceptable clinical effect in patients with recurrent LVOTO after alcohol septal ablation. The procedure can precisely resect the hypertrophic septal myocardium while avoiding serious complications such as septal perforation or complete atrioventricular block.

Mid-term effectiveness of hip preservation in the reconstruction of ultrashort bone segments in the proximal femur with three-dimensional printed customized cementless intercalary endoprosthesis with an intra-neck curved stem / 中国修复重建外科杂志

OBJECTIVE@#To explore the design points of a three-dimensional (3D) printed customized cementless intercalary endoprosthesis with an intra-neck curved stem and to evaluate the key points and mid-term effectiveness of its application in the reconstruction of ultrashort bone segments in the proximal femur.@*METHODS@#Between October 2015 and January 2021, 17 patients underwent reconstruction with a 3D printed-customized cementless intercalary endoprosthesis with an intra-neck curved stem. There were 11 males and 6 females, the age ranged from 10 to 76 years, with an average of 30.1 years. There were 9 cases of osteosarcoma, 4 cases of Ewing sarcoma, 2 cases of chondrosarcoma, 1 case of liposarcoma, and 1 case of myofibroblastoma. The disease duration was 5-14 months, with an average of 9.5 months. Enneking staging included 16 cases of stage ⅡB and 1 case of stage ⅢB. The distances from the center of the femoral head to the body midline and the acetabular apex were measured preoperatively on X-ray images. Additionally, the distances from the tip of the intra-neck curved stem to the body midline and the acetabular apex were measured at immediate postoperatively and last follow-up. The neck-shaft angle was also measured preoperatively, at immediate postoperatively, and at last follow-up. The status of osseointegration at the bone-prosthesis interface and bone growth into the prosthesis surface were assessed by X-ray films, CT, and Tomosynthesis-Shimadzu metal artefact reduction technology (T-SMART). The survival status of the patients, presence of local recurrence or distant metastasis, and occurrence of postoperative complications were assessed. The recovery of lower limb function was evaluated pre- and post-operatively using the Musculoskeletal Tumor Society (MSTS) scoring system, and pain relief was evaluated using the visual analogue scale (VAS) scores.@*RESULTS@#The patient's femoral resection length was (163.1±57.5) mm, the remaining proximal femoral length was (69.6±9.3) mm, and the percentage of femoral resection length/total femoral length was 38.7%±14.6%. All 17 patients were followed up 25-86 months with an average of 58.1 months. During the follow-up, 1 patient died of lung metastasis at 46 months postoperatively, and the remaining 16 patients survived tumor-free. There was no complication such as periprosthetic infection, delayed incision healing, aseptic loosening, prosthesis fracture, or periprosthetic fracture. No evidence of micromotion or wear around the implanted stem of the prosthesis was detected in X-ray and T-SMART evaluations. There was no significant radiolucent lines, and radiographic evidence of bone ingrowth into the bone-prosthesis interface was observed in all stems. There was no significant difference in the distance from the tip of the curved stem to the body midline and the apex of the acetabulum at immediate postoperatively and last follow-up compared with the distance from the center of the femoral head to the body midline and the apex of the acetabulum before operation, respectively (P>0.05), and there was no significant difference in the above indexes between immediate postoperatively and last follow-up (P>0.05). The differences in the neck-shaft angle at various time points before and after operation were also not significant (P>0.05). At last follow-up, the MSTS score was 26.1±1.2 and the VAS score was 0.1±0.5, which were significantly improved when compared with those before operation [19.4±2.1 and 5.7±1.0, respectively] (t=14.735, P<0.001; t=21.301, P<0.001). At last follow-up, none of the patients walked with the aid of crutches or other walkers.@*CONCLUSION@#The 3D printed customized cementless intercalary endoprosthesis with an intra-neck curved stem is an effective method for reconstructing ultrashort bone segments in the proximal femur following malignant tumor resection. The operation is reliable, the postoperative lower limb function is satisfactory, and the incidence of complications is low.

Aplicación clínica de la Impresión 3D en el manejo de fracturas abiertas de tibia: Nuevas fronteras en Traumatología. Estudio experimental / Clinical application of 3D Printing in open tibial fractures management: New frontiers of Orthopaedics. An experimental study

La Impresión 3D es una tecnología emergente utilizada cada vez más en medicina. En los países en vías de desarrollo, donde las fracturas por motocicletas y automóviles se encuentran en aumento, la disponibilidad de fijadores externos para el manejo de fracturas abiertas es un problema frecuente. La impresión 3D puede ser una alternativa económica e igualmente confiable a los dispositivos tradicionales elaborados con acero o titanio. El objetivo de este trabajo es mostrar la experiencia con el uso de Impresión 3D y su aplicación en el manejo clínico de fracturas abiertas diafisiarias de tibia. Se realizó un estudio pre-experimental y prospectivo. Se incluyeron 14 pacientes con fracturas de tibia AO/ASIF 42A, 42B y 42C tratados con un fijador externo con rótulas elaboradas con Impresión 3D como medida de Control de Daños en Ortopedia desde su ingreso hasta su resolución definitiva. Todos los pacientes fueron de sexo masculino, con un promedio de edad 23,16 años con 50% entre 20-23 años. Las fracturas fueron 42,85% tipo 42A, 37,71% 42B y 21,42% 42C. El 78,57% de las fracturas fueron ocasionadas por motocicletas: 57,14% grado II según Gustilo y Anderson, un 28,57% grado III y 14,28% grado I. El 37,71% eran politraumatizados. Ninguno de los pacientes presentó complicaciones como pérdida de la reducción, aflojamiento de las rótulas, ruptura o fatiga de las rótulas ni fatiga de la barra. La impresión 3D demostró ser una herramienta y alternativa útil en el manejo agudo de fracturas abiertas diafisiarias de tibia(AU)

3D Printing is an emerging technology used more and more in medicine. In developing countries, where motorcycle and automobile fractures are on the rise, the availability of external fixators for the management of open fractures is a frequent problem. 3D printing can be a cheap and equally reliable alternative to traditional devices made of steel or titanium. The objective of this work is to show the experience with the use of 3D Printing and its application in the clinical management of open diaphyseal fractures of the tibia. A pre-experimental and prospective study was made. 14 patients with AO/ASIF tibia fractures 42A, 42B and 42C treated with an external fixator with 3D-printed ball-caps as a Damage Control measure in Orthopedics from admission to final resolution were included. All patients were male, with an average age of 23,16 years, 50% between 20-23 years. The fractures were 42,85% type 42A, 37,71% 42B and 21,42% 42C. 78,57% of the fractures were caused by motorcycles: 57,14% grade II according to Gustilo and Anderson, 28,57% grade III and 14.28% grade I. 37,71% were polytraumatized. None of the patients had complications such as loss of reduction, loosening of the patellas, rupture or fatigue of the patellas, or rod fatigue. 3D printing proved to be a useful tool and alternative in the acute management of open diaphyseal fractures of the tibia(AU)