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SUMMARY: To measure and study the anatomical morphological data of the lumbar 5 to sacral 1 intervertebral space with the aid of CT and design an anatomical anterior lumbosacral 3D printed integrated interbody fusion for the treatment of degenerative lumbosacral spine diseases. 100 adults (50 of each sex) who underwent CT examination of the lumbar spine in our hospital were selected, and their lumbar 5 to sacral 1 intervertebral space anatomical data were measured, including the anterior lumbar convexity angle, different sagittal and coronal heights, and the sagittal and coronal diameters of the superior and inferior endplates. The measured data were also statistically analyzed, and morphological design and study of the 3D printed integrated fusion device in the anterior lumbosacral spine was performed by applying computer software. When comparing the coronal and sagittal diameters of the superior and inferior endplates from lumbar 5 to sacral 1, the differences were statistically greater in men than in women (P0.001). When comparing the height at different positions in the median sagittal plane, both males and females showed an anterior high and posterior low pattern. In the coronal plane, both males and females showed the highest height in the middle position (P0.001). CT can measure the anatomical data of the lumbosacral spinal hiatus more accurately. The 3D-printed anterior integrated fusion device of the lumbosacral spine designed according to the analysis of the data results is more in line with the anatomical structure of the lumbosacral spine, fits well with the superior and inferior endplates, and effectively restores the height and anterior convexity angle of the lumbosacral space.
El objetivo de este trabajo fue medir y estudiar los datos morfológicos anatómicos del espacio intervertebral lumbar 5 a sacro 1 con la ayuda de TC y diseñar una fusión intersomática integrada anatómica lumbosacra anterior impresa en 3D para el tratamiento de enfermedades degenerativas de la columna lumbosacra. Se seleccionaron en nuestro hospital 100 adultos (50 de cada sexo) que se sometieron a un examen de TC de la columna lumbar y se midieron los datos anatómicos del espacio intervertebral lumbar 5 al sacro 1, incluyendo el ángulo de la convexidad lumbar anterior, diferentes alturas sagital y coronal, y los diámetros sagital y coronal de las placas terminales superior e inferior. Los datos medidos también se analizaron estadísticamente y se realizó el diseño morfológico y el estudio del dispositivo de fusión integrado impreso en 3D en la columna lumbosacra anterior mediante la aplicación de software informático. Al comparar los diámetros coronal y sagital de las placas terminales superior e inferior desde lumbar 5 hasta sacro 1, las diferencias fueron estadísticamente mayores en hombres que en mujeres (P 0,001). Al comparar la altura en diferentes posiciones en el plano mediano, tanto hombres como mujeres mostraron un patrón anterior alto y posterior bajo. En el plano coronal, tanto hombres como mujeres mostraron la altura más alta en la posición media (P0,001). La TC puede medir los datos anatómicos del hiato espinal lumbosacro con mayor precisión. El dispositivo de fusión anterior integrado impreso en 3D de la columna lumbosacra diseñado de acuerdo con el análisis de los resultados de los datos está más en línea con la estructura anatómica de la columna lumbosacra, se adapta bien a las placas terminales superior e inferior y restaura eficazmente la altura y la parte anterior del ángulo de convexidad del espacio lumbosacro.
Sujets)
Humains , Mâle , Femelle , Adolescent , Adulte , Jeune adulte , Impression tridimensionnelle , Vertèbres lombales/imagerie diagnostique , Rachis , Tomodensitométrie hélicoïdale , Vertèbres lombales/anatomie et histologieRésumé
The objective of the study is to assess the precision of digital impressions in removable partial dentures through an in vitro study on the degree of abutment adaptation. A Kennedy Class III model with a prosthetic space between elements 43 and 47, featuring niches in the mesio-occlusal and cingulum regions, respectively. Conventional impressions were performed in subgroups CONC and CONM, while digital scanning was conducted in subgroups DIGC and DIGM. Simplified cobalt-chromium alloy frameworks were manufactured using the lost-wax technique on plaster and resin models. The degree of adaptation of the structures was evaluated by impressing the niches with condensation silicone, qualitatively assessing perforations, and quantitatively measuring the mold thickness under a stereomicroscope after cross-sectioning. Regular adaptation was more prevalent among the experimental groups. CONC showed a higher mean degree of abutment adaptation, while CONM had a lower mean. The study factors, impression technique, and type of abutment seat, were not statistically significant, with no interaction among the variables. Occlusal and cingulum abutment measurement points, in both impression techniques, showed no statistically significant difference. Digital scanning yielded better results in terms of abutment adaptation, with smaller average gaps between the abutment seat and the metal structure, making it clinically acceptable. The type of abutment seat and the impression technique did not have a statistically significant impact on abutment adaptation. The impression technique does not represent a factor influencing the adaptation of occlusal and cingulum abutments at different measurement points. (AU)
O Objetivo do estudo é valiar precisão da impressão digital em próteses parciais removíveis, por meio de um estudo in vitro sobre o grau de adaptação dos apoios. Um modelo Classe III de Kennedy com espaço protético entre o elemento 43 e 47, nichos na região mésio-oclusal e na do cíngulo. Foram realizadas impressões convencionais nos subgrupos CONC e CONM, e digitalização nos subgrupos DIGC e DIGM, onde estruturas simplificadas de liga de Co-Cr foram fabricadas usando a técnica de fundição perdida nos modelos de gesso e resina. O grau de adaptação das estruturas foi avaliado pela impressão dos nichos com silicone de condensação, qualitativamente as perfurações e quantitativamente a espessura do molde em um estereomicroscópio após seção transversal. A adaptação regular foi mais prevalente entre os grupos experimentais. CONC maior média do grau de adaptação do apoio, enquanto CONM menor média. Os fatores do estudo, técnica de impressão e tipo de assento de apoio, não foram estatisticamente significativos, sem interação entre as variáveis. Pontos de medição de apoio oclusal e de cíngulo, em ambas as técnicas de impressão, sem diferença estatisticamente significativa. A digitalização mostrou melhores resultados em relação ao grau de adaptação dos apoios, com menores lacunas médias entre o assento de apoio e a estrutura metálica, sendo clinicamente aceitável. O tipo de assento de apoio e a técnica de impressão não interferem estatisticamente na adaptação dos apoios. A técnica de impressão não representa um fator que influencie a adaptação de apoios oclusais e de cíngulo em diferentes pontos de medição. (AU)
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Actualmente los factores que influyen en la supervivencia de los dientes trasplantados han podido ser controlados con el uso de la tecnología. El autotrasplante dental guiado ha logrado más predictibilidad y eficiencia, además, h a reducido los tiempos de transferencia desde la extracción hasta el trasplante. El objetivo de esta revisión es describir los protocolos de autotrasplante dental guiado, sus tasas de supervivencia y éxito publicados en la literatura actual. Esta revisió n fue realizada siguiendo la pauta PRISMA. La búsqueda se realizó en MEDLINE, Google Académico, ScienceDirect y SciELO, con los términos "autotransplant", "autotransplantation", "autotransplanting", "dental", "tooth", "teeth", "guided", "guide" con filtro de publicación de 10 años. Se realizó evaluación de riesgo de sesgo mediante pautas Joanna Briggs Institute (JBI) a los estudios, incluyendo en esta revisión sólo con riesgo medio y bajo. Los datos de cada artículo se tabularon en una tabla realizada en el procesador de texto en línea "Google Docs". Diez estudios cumplieron los criterios mencionados y fueron incluidos. Fueron evaluados un total de 37 pacientes entre 9 a 64 años. Los dientes donantes más frecuentes fueron premolares y terceros molares. En la mayoría de los casos los pacientes se encontraban sin antecedentes mórbidos de relevancia. El éxito fue evaluado mediante diversos criterios clínicos y radiográficos. Por otro lado, la supervivencia fue evaluada durante los seguimientos respecto a la permanencia del diente en boca. Este tipo de tratamiento no es muy conocido y los estudios incluidos fueron escasos, por otro lado, estos son de bajo nivel de evidencia (reportes de casos y serie de casos). Los protocolos evaluados difieren en algunas características, sin embargo, todos logran altas tasas de supervivencia y éxito. Igualmente, se presentan algunos fracasos, dónde los dientes debieron ser extraídos por movilidad e inflamación.
Currently, the factors that influence the survival of transplanted teeth have been controlled with the use of technology. Guided dental autotransplantation has achieved greater predictability and efficiency, and has also reduced transfer times from extraction to transplantation. The aim of this review is to describe the protocols of guided dental autotransplantation, their survival and success rates published in the current literature. This review was performed following the PRISMA guideline. The search was carried out in MEDLINE, Google Scholar, ScienceDirect and SciELO, with the terms "autotransplant", "autotransplantation", "autotransplanting", "autotransplanting", "dental", "tooth", "teeth", "guided", "guide" with a 10-year publication filter. Studies were assessed for risk of bias using Joanna Briggs Institute (JBI) guidelines, including only medium and low risk studies in this review. The data for each article were tabulated in a table created in the online word processor "Google Docs". Ten studies met the selection criteria and were included. A total of 37 patients between 9 and 64 years of age were evaluated. The most frequent donor teeth were premolars and third molars. In most cases the patients had no relevant morbid history. Success was evaluated by means of various clinical and radiographic criteria. On the other hand, survival was evaluated during the follow-ups with respect to the permanence of the tooth in the mouth. This type of treatment is not very well known, and the studies included were scarce; on the other hand, they are of a low level of evidence (case reports and case series). The evaluated protocols differ in some characteristics, however, all of them achieve high survival and success rates. There are also some failures, where teeth had to be extracted due to mobility and inflammation.
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【Objective】 To construct a 3D printed PLLA/β-tricalcium (PLLA/β-TCP) bone tissue engineering scaffold surface porous structure through simple treatment with NaOH solution, increase the roughness and hydrophilicity of the scaffold, and promote cell adhesion on the scaffold surface. 【Methods】 The PLLA/β-TCP mesh scaffold was prepared by 3D printing melt deposition molding technology, and the scaffold was roughed by NaOH etching. The effects of NaOH concentration and time on the scaffold were observed according to the microstructure, energy spectrum, contact angle, mechanics, and cell adhesion of the scaffold. 【Results】 The PLLA/β-TCP composite scaffold constructed by melt deposition technology had a pre-set porous structure, and the pores were interconnected. After NaOH etching, a porous structure with both macroscopic and microscopic pores was formed. The increase in any of the NaOH concentration and time parameters would lead to the increase of pore diameter and surface roughness. When the NaOH treatment parameter was 0.1 mol/L (9 h), it could significantly reduce the water contact angle on the surface of the scaffold, and had no significant effect on the compressive strength of the scaffold. In vitro cell testing showed that the surface porous composite scaffold etched with NaOH had more advantages in the adhesion and proliferation of BMSCs. 【Conclusion】 Using NaOH to process 3D printing of PLLA/β-TCP bone tissue engineering scaffolds can effectively improve the surface morphology of the scaffold, and optimize its hydrophilicity and cell adhesion.
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【Objective】 To solve the problem of insufficient hydrophilicity on the surface of polycaprolactone (PCL)/β-TCP bone tissue engineering scaffolds, NaOH etching method was used to improve the surface microstructure of 3D printed PCL/β-TCP scaffolds, further affecting their hydrophilicity and cell response. 【Methods】 PCL/β-TCP mesh scaffolds were prepared using 3D printing melt deposition molding technology, and the surface roughness of the scaffolds was modified by NaOH etching. The effects of two reaction parameters, NaOH concentration and time, on the microstructure, spectral elements, contact angle, compressive strength, and cell adhesion of the scaffolds before and after modification were observed. 【Results】 After NaOH etching, the surface microporous structure of the mesh scaffold was successfully prepared. With the increase of either NaOH concentration or time, the surface micropores of the scaffold increased while the contact angle of the material surface decreased. However, the compression strength of the etched scaffold treated with NaOH for 1 mol/L (24 h) or 10 mol/L (6 h) was not statistically significant compared to the untreated group (P>0.05). The number of cells on the etched scaffold increased, with a larger spreading area of individual cells, making it more advantageous in the adhesion and proliferation of BMSCs. 【Conclusion】 The use of NaOH etching to improve the hydrophilicity of 3D printed PCL/β-TCP bone tissue engineering scaffolds is a low-cost and effective strategy which can effectively improve the wettability and cell adhesion of the scaffolds.
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Objective To investigate the influence of different cell structures on the static and dynamic mechanical performance of porous titanium alloy scaffolds,and to provide a theoretical mechanical basis for the application of scaffolds in the repair of mandibular bone defects.Methods Porous titanium alloy scaffolds with diamond,cubic,and cross-sectional cubic cell structures were manufactured using three-dimensional printing technology.Uniaxial compression tests and ratcheting fatigue with compression load tests were conducted to analyze the static and dynamic mechanical performances of scaffolds with different cell structures.Results The elastic moduli of the diamond cell,cross-sectional cubic cell,and cubic cell scaffolds were 1.17,0.566,and 0.322 GPa,respectively,and the yield strengths were 71.8,65.1,and 31.8 MPa,respectively.After reaching the stable stage,the ratcheting strains of the cross-sectional cubic,diamond,and cubic cell scaffolds were 3.3%,4.0%,and 4.5%,respectively.The ratcheting strain increased with increasing average stress,stress amplitude,and peak holding time,and decreased with increasing loading rate.Conclusions The evaluation results of the static mechanical performance showed that the diamond cell scaffold was the best,followed by the cross-sectional cubic cell scaffold and the cubic cell scaffold.The evaluation results of the dynamic mechanical performance showed that the cross-sectional cubic cell scaffold performed the best,followed by the diamond cell scaffold,whereas the cubic cell scaffold performed the worst.The fatigue performance of the scaffold is affected by the loading conditions.These results provide new insights for scaffold construction for the repair of mandibular bone defects and provide an experimental basis for further clinical applications of this scaffold technology.
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Objective To study the mechanical properties of titanium mesh and three-dimensional(3D)-printed metal vertebral body substitutes(VBS)to provide guidance for the selection and structural optimization of artificial vertebral implants in clinical practice.Methods The equivalent elastic modulus,equivalent yield strength,and structural failure mode of titanium mesh and 3D-printed porous,truss,and topologically optimized VBS were systematically investigated using compression tests.Results The elastic modulus of the titanium mesh(2 908.73±287.39 MPa)was only lower than that of the topologically optimized VBS.However,their structural strengths and stabilities were inadequate.The yield strength of the titanium mesh(46.61±4.85 MPa)was only higher than that of the porous VBS and it was the first to yield during compression.The porous VBS was insufficient for use as the vertebral implant owing to its poor mechanical strength(18.14±0.17 MPa-25.79±0.40 MPa).The truss VBS had good elastic modulus(2 477.86±55.19 MPa-2 620.08±194.36 MPa)and strength(77.61±0.50 MPa-88.42±1.07 MPa).However,the structural stability of the truss VBS was insufficient,and instability occurred easily during compression.The topologically optimized VBS had the highest elastic modulus(3 746.28±183.80 MPa)and yield strength(177.43±3.82 MPa)among all the tested VBS types,which could provide improved security and stability for artificial vertebral implant in vivo services.Conclusions Topology optimization results in a high strength and high stability VBS design.Moreover,it provides a large design space and great safety margin to provide increased possibilities for lightweight and new material design of future artificial vertebral implants.
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Transcatheter aortic valve replacement(TAVR)is currently one of the main therapeutic strategies for aortic valve disease.Preoperative imaging assessment is crucial for operation project planning and prevention of procedure-associated complications.Different from planar image reconstruction,3D printing technology can accurately depict the anatomical structure of the aortic root.It enables further assessment of operative risk and therapeutic strategy through in vitro simulation,especially for assessing the risk of coronary artery obstruction and planning interventional procedures.Here,we report on two patients who underwent a 3D printing aortic root anatomical simulation model,followed an by in vitro balloon dilatation/valve implantation test,to evaluate the risk of coronary artery obstruction suggested by CT angiography planar image reconstruction before TAVR.
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Objectives:To explore the accuracy of pedicle screw placement assisted with improved 3D-print-ed drill guiding template in cervical spine.Methods:The clinical data of 60 patients undergone posterior cervical pedicle screw placement in our hospital between January 2016 and January 2023 were analyzed retro-spectively,including 30 males and 30 females with an average age of 17-84 years(58.7±13.8 years).The pa-tients were divided into guiding template group and free-hand group based on whether the guiding template was used to assist the placement of screws or not.The improved 3D-printed guiding template was used to assist cervical pedicle screw placement in the guiding template group(n=30),and the self-made angular-ruler was used in the free-hand group(n=30).There was no significant difference in age,gender ratio,and preoper-ative diagnosis between the two groups(P＞0.05).Cervical CT scan was performed at one week after surgery,and the accuracy of pedicle screw placement was evaluated according to the Kaneyama standard:Grade 0,the screw was completely in the pedicle;Grade 1,the size of screw penetrating the cortex＜50%of the screw diameter;Grade 2,the size of screw penetrating the cortex≥50%of the screw diameter but not com pletely out;Grade 3,the screw was completely on the outside of the pedicle.The accuracy of pedicle screw placement(ratio of grades 0 and 1)and complications such as vascular and nerve injury,incision infection,cerebrospinal fluid leakage,screw loosening and breakage caused by screw misplacement were recorded.Re-sults:A total of 152 pedicle screws were placed in the guiding template group,including 74 screws of grade 0,68 of grade 1,10 of grade 2 and 0 of grade 3,with an accuracy of screw placement of 93.4%.A total of 136 pedicle screws were placed in free-hand group,including 53 screws of grade 0,61 of grade 1,18 of grade 2 and 4 of grade 3,with an accuracy of screw placement of 83.8%.The accuracy of screw placement in the guiding template group was significantly higher than that in the free-hand group(P＜0.05).There were no related complications such as vascular and nerve injury,incision infection and cerebrospinal fluid leakage caused by misplacement of pedicle screws.The patients were followed up for 5-29 months(14.2±7.7months),and there were no complications such as screw loosening or breakage.Conclusions:Improved 3D-printed drill guiding template can improve the accuracy of pedicle screw placement in cervical spine.
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Objective:To explore the short-term outcomes of 3D-printing stand-alone artificial vertebral body(AVB)in the surgical procedure of anterior cervical corpectomy and fusion(ACCF).Methods:Following the proposal of IDEAL(idea,development,exploration,assessment,and long-term follow-up)framework,we designed and conducted this single-armed,retrospective cohort study.The patients with cervical spondylotic myelopathy were recruited,and these patients exclusively received the surgical procedure of single-level ACCF in our single center.After the process of corpectomy,the size was tailored using different trials and the most suitable stand-alone AVB was then implanted.This AVB was manufactured by the fashion of 3D-printing.Two pairs of screws were inserted in an inclined way into the adjacent vertebral bodies,to stabilize the AVB.The participants were regularly followed-up after the operation.Their clinical data were thoroughly reviewed.We assessed the neurological status according to Japanese Orthopedic Association(JOA)scale.We determined the fusion based on imaging examination six months after the operation.The recorded clinical data were analyzed using specific software and they presented in suitable styles.Paired t test was employed in comparison analysis.Results:In total,there were eleven patients being recruited eventually.The patients were all followed up over six months after the operation.The mean age of the cohort was(57.2±10.2)years.The mean operation time was(76.1±23.1)min and the median bleeding volume was 150(100,200)mL.The postoperative course was uneventful for all the cases.Dysphagia,emergent hematoma,and deterioration of neurological func-tion did not occur.Mean JOA scores were 13.2±2.2 before the operation and 16.3±0.8 at the final follow-up,which were significantly different(P＜0.001).The mean recovery rate of neurological func-tion was 85.9％.By comparing the imaging examinations postoperatively and six months after the opera-tion,we found that the average subsidence length was(1.2±1.1)mm,and that there was only one ca-ses(9.1％)of the severe subsidence(＞3 mm).We observed significant improvement of cervical lor-dosis after the operation(P=0.013).All the cases obtained solid fusion.Conclusion:3D-printing stand-alone AVB presented favorable short-term outcome in one-level ACCF in this study.The fusion rate of this zero-profile prosthesis was satisfactory and the complication rate was relatively low.
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Objective:To analyze the influence of forming direction on the surface characteristics,elastic modulus,bending strength and fracture toughness of printed parts and the relationship between forming direction and force direction,and to provide scientific basis and guidance for the clinical applica-tion of oral denture base resin materials.Methods:The 3D printing technology was used to print denture base resin samples.The shape and size of the samples referred to the current standard for testing conven-tional denture base materials.The samples used for physical performance testing were cylindrical(with a diameter of 15 mm and a thickness of 1 mm)and printed at different angles along the Z axis(0°,45°,90°).Scanning electron microscope was used to observe the microscopic topography of the different sam-ples.The color stability of different samples was observed by color stabilizer.The surface roughness of the samples was analyzed by using surface roughness tester.The Vickers hardness was measured to ana-lyze the hardness of the samples.The samples used for mechanical performance testing were rectangular(elastic modulus and bending strength:A length of 64 mm,a width of 10 mm,and a height of 3.3 mm;fracture toughness:A length of 39 mm,a width of 8 mm,and a height of 4 mm),divided into two groups:W group and H group.The W group was printed from the bottom up along the Z axis with the length × width as the bottom surface parallel to the X,Y axis plane,while the H group printed from the bottom up along the Z axis with the length × height as the bottom surface parallel to the X,Y axis plane.The forming angles of both groups were equally divided into 0°,45°,and 90°.The elastic modulus,bending strength and fracture toughness of different samples were studied through universal mechanical testing machine.SPSS 22.0 software was used for statistical analysis.Results:The microscopic topogra-phy and roughness of different samples were closely related to the printing direction,with significant differences between the 0°,45°,and 90° specimens.The 0° specimens had the smoothest surface(roughness＜1 μm).The surface of the 45 ° specimen was the roughest(roughness＞3 μm).The microhardness of the 0° sample was the best[(196.13±0.20)MPa],with a significant difference com-pared with the 90° sample[(186.62±4.81)MPa,P＜0.05].The mechanical properties of different samples were also closely related to the printing direction.The elastic modulus,bending strength,and fracture toughness of the 45° samples in the W group were the highest compared with the other groups.The results of elastic modulus showed that in the H group,the 45° specimens had the highest elastic mo-dulus,which was significantly different from the 0° and 90° specimens(P＜0.05).The elastic modulus of 0° and 45° specimens in the W group were higher than those in 90° specimens(P＜0.05).The bending strength results showed that there was no significant difference between the specimens from dif-ferent angles in the H group.The bending strength of the 90° specimens in the W group was the smallest,and there was a significant difference between 90° and the 0° and 45° specimens(P＜0.05);And the bendind strength of the 0° and 45° specimens in the W group was significantly higher than that of the 0° and 45° specimens in the H group(P＜0.05).The fracture toughness results showed that the fracture toughness of the H group specimens was lower than 1.9 MPa m1/2,which was specified in the denture base standard.The 45° samples in the W group were the highest,with significant differences compared with the 0° and 90° samples(P＜0.05).And the 90° samples of the W group specimens were lower than 1.9 MPa m1/2.And the fracture toughness of the 45° specimen in the W group was significantly higher than that of all the specimens in the H group(P＜0.05).Conclusion:The 0° samples had rela-tively better physical properties.The 45° samples had the best mechanical properties.But the fracture toughness of specimens(H group and 90° samples of W group)did not yet meet clinical requirements.That indicated that the characteristics of the 3D printing denture base resin were affected by the printing direction.Only when the performance of the printed samples in all directions met the minimum require-ments of the standard,they could be used in clinical practice.
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Patent ductus arteriosus（PDA）is one of the most common congenital heart diseases in childhood.The prevalence of PDA is about 0.5% and PDA accounts for 5%-10% of congenital heart diseases. Continuous opening of the ductus arteriosus can affect children's growth and development. Meanwhile，PDA increases the possibility of pneumonia，infective endocarditis，neonatal necrotizing enterocolitis，and other diseases.Compared with traditional surgery，percutaneous interventional closure of PDA in children has a higher surgical success rate and shorter hospital stay. Clinical practice has proved that percutaneous interventional closure is the preferred method for children with PDA. However，transcatheter closure also has complications，including displacement，valvular regurgitation，hemolysis and thrombocytopenia. The review aims to illustrate the mechanism and treatment of the complications after PDA interventional closure，in order to increase the physician's awareness of those complications，reduce the incidence of the complications and improve the prognosis of the patients.
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Objective:Anterior cruciate ligament injury is the most common type of knee joint ligament injury.Anterior cruciate ligament reconstruction has a high failure rate,with bone tunnel abnormalities as the most significant factor in these failures.Digital orthopedic technology can effectively develop implementation plans for the revision,thus increasing the success rate.This study aims to develop a surgical plan for anterior cruciate ligament revision by employing multiplanar reconstruction(MPR)for measuring bone tunnel position and diameter,and simulating bone tunnel creation via 3D printing preoperatively. Methods:A total of 12 patients who underwent anterior cruciate ligament revision at the Third Xiangya Hospital of Central South University between 2014 and 2021 were retrospectively studied.The data included patient demographics,preoperative formulated knee joint 3D printing models,and preoperative knee CT scans.The study measured the bone tunnel's diameter and position to guide the establishment of revision bone tunnels during surgery,reassessed the postoperative bone tunnels,and evaluated knee joint functional scores[including International Knee Documentation Committee Knee Evaluation Form(IKDC)score,Lysholm score,and Tegner exercise level score]. Results:Preoperative measurements revealed suboptimal femoral tunnels positions in 4 patients and tibial tunnels positions in 2 patients.MPR and 3D printing technology were used to guide the establishment of a new bone canal during surgery,and postoperative measurements were satisfactory for all patients.Preoperative measurements demonstrated the interclass correlation coefficient for femoral tunnels and tibial tunnels diameters were 0.843(P<0.05)and 0.889(P<0.001),respectively.Meanwhile,the intraclass correlation coefficient were 0.811(P<0.05)and 0.784(P<0.05),respectively.The intraoperative diameter of femoral and tibial tunnels showed excellent correlation with postoperative CT measurements,with intraclass correlation coefficient values of 0.995(P<0.001)and 0.987(P<0.001),respectively.All bone tunnel positions were within the normal range.At the final follow-up,knee joint function scores in all 12 patients improved significantly compared to pre-surgery(P<0.001),and the reoperation rate was zero. Conclusion:MPR and 3D printing technology can accurately measure the parameters of reconstructed anterior cruciate ligament bone tunnels.Personalized revision plans for patients with reconstruction failure enhances the success rate of revision surgery and improves patient prognosis.
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Objective To explore the application effect of new improved 3D printing individualized guidance(3D psi)in total knee arthroplasty(TKA)for knee osteoarthritis(KOA).Methods A total of 100 patients with KOA in 920th Hospital of Joint Logistics Support Force,PLA from January 2021 to January 2022 were selected,and were divided into 2 groups of 50 patients each using the randomized numerical table method.The control group was treated with conventional TKA,and the study group was treated with new improved 3D psi assisted TKA.The operation conditions,postoperative rehabilitation,complications,prosthesis component position deviation,knee range of motion(ROM),lower limb force line parameters[coronal distal femoral mechanical axis lateral angle(mldfa),lower limb mechanical axis angle(HKA)],gait parameters(percentage of support time,stride,pace),knee function(HSS score),quality of life(AIMS2 score)were observed.Results Com-pared with control group,the amount of intraoperative and postoperative blood loss and drainage volume 2 days after operation were less in the study group,and the operation time and hospital stay were shorter(P<0.05).The deviations of LTC Angle,FFC Angle,HKA Angle,LFC Angle and FTC Angle in the study group were smaller than those in the control group(P<0.05).At 3 months,6 months and 12 months after surgery,the percentage of knee ROM,supporting time,stride length and walking speed of the research group were higher than those of the control group,while the coronal-position mLDFA and HKA were lower than those of the control group(P<0.05).The proportion of WBC and PMN in joint fluid at 3 months,6 months and 12 months after surgery was lower than that in control group(P<0.05).The HSS score of the study group was higher than that of the control group at 3 months,6 months and 12 months after operation,and the AIMS2 score was lower than that of the control group(P<0.05).There was no statistically significant difference in the incidence of complications between the study group and the control group(P>0.05).Conclusion The new improved 3D PSI-assisted TKA treatment of KOA can optimize the surgical situation,improve operating accuracy,improve the patient's lower limb alignment,promote limb function recovery,help improve the quality of life,and has high safety.
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Objective·To evaluate the effects of anterior maxillary segmental distraction osteogenesis(AMSDO)in treating sagittal maxillary hypoplasia in cleft lip and palate(CLP)patients and to report a 3D-printed surgical guide to facilitate the osteotomy.Methods·Twelve patients with CLP who underwent AMSDO were included in this study.Virtual osteotomy was performed in a 3-dimensional model and the osteotomy line were fabricated into a tooth-borne surgical guide by using 3D-printing technique.Lateral cephalograms taken before surgery(T0),at the end of consolidation(T1)and six months after consolidation(T2)were used to evaluate the effects of AMSDO.The accuracy of the osteotomy guide was measured by superimposing the postoperative CT data to virtual planning.Results·All the patients went through surgery without serious complications.SNA and overjet changed significantly both from T0 to T1 and from T0 to T2.ANB,facial convexity,and palatal length changed without significance from T0 to T1 and from T0 to T2.SNB remained stable.All the variables remained relatively stable from T1 to T2.The anteroposterior linear root-mean-square deviation(RMSD)between planning and actual results was 0.90 mm,while the angular RMSD in the sagittal plane was 5.07°.Conclusion·AMSDO is an effective treatment for maxillary hypoplasia secondary to CLP.The accuracy of this 3D-printed osteotomy guide is clinically acceptable,and this can simplify the surgery with fewer complications.
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With the development of digital technology,computer-aided design and manufacturing(CAD/CAM)combined with 3D printing technology is increasingly used in clinical and teaching applications in dentistry.In clinical dentistry,3D printing technology has been widely used in oral and maxillofacial surgery,orthodontics and implantation.Traditional oral laboratory teaching usually uses extracted teeth,resin teeth or various dental models,while 3D printing of oral models can achieve standardized,mass-produced and close-to-real clinical application,which better meets the needs of clinical pre-practice teaching.This article reviews the latest educa-tional applications of 3D printing of dental models in teaching of oral restoration,dental pulp-cavity,oral and maxillofacial surgery,and summarizes the selection of different printing processes and printing materials,aiming to apply the research strategy of 3D printing technology in pre-clinical teaching in dentistry.Finally,the article explores the trends and urgent problems that need to be solved in the development of 3D printed dental models.
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Prosthodontic dentures are used to treat tooth defects,dentition defects and dentition loss,which can restore the appearance and function of the patient's oral cavity.With the advent of the digital age,3D printing technologies have slowly gained widespread popularity.In the field of prosthodontics,3D printing can manufacture materials including resins,waxes,metals,and ceramics.Besides,it can produce fixed,movable,implant dentures and dental models required for dentures.3D printing can produce complicated things with a high material consump-tion rate,simplifying denture manufacture.In addition,the accuracy of 3D printed prosthesis is directly related to the comfort and durability.This article summarizes the process of accuracy of 3D printed dental prosthesis at home and abroad in recent years and provides clues for better 3D printing application.
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BACKGROUND:In recent years,many studies have confirmed that assembloids can make up for the shortcomings of organoids,which cannot fully reproduce the interaction between cell and cell and between cell and matrix.Since the assembloids construction methods are in the early stage of development,there is no unified standard. OBJECTIVE:To review the current construction methods,applications,advantages,and disadvantages of assembloids,guide the development and improvement of vitro cell models. METHODS:PubMed,CNKI,and WanFang databases were searched with English search terms"assembloids,organoids,tumor microenvironment,organoids AND assemble,organoids AND microenvironment"and Chinese search terms"assembloids,organoids,tumor microenvironment,organoid reorganization,multicellular model".Totally 94 articles were screened out for review after excluding irrelevant articles and deduplication. RESULTS AND CONCLUSION:(1)According to the different sources of cells,the construction of assembloids can be divided into three methods:self-assembly,direct-assembly,and mixed-assembly.According to the differences of cell culture methods,it can be divided into suspension culture method,matrix culture method,organ chip culture method,and 3D bio-printing.(2)The process of self-assembly covers early stages of cell and tissue development,so it has broad prospects in the fields of organ development and developmental disorders.The function of differentiated mature cells is relatively perfect,and the assembloids directly assembled by them have more potential in the study of functional disorders and cell-damaging diseases.Self-assembly may be better in organ transplantation,and direct-assembly will be more suitable for the repair of tissue damage.Mixed-assembly combines the advantages of the former two and is mostly used to explore the physiological and pathological mechanisms of cells in the microenvironment,as well as drug screening.(3)Although different assembloids have their own advantages,they all face the problem of imperfect vasculature system,then,each method has its own limitations,for example,the degree of cell differentiation in self-assembly assembloids may still be different from that in vivo,and the fixed cell types in direct-assembly models cannot simulate complex microenvironments in vivo.These are urgent problems to be solved.(4)In the future,with the continuous improvement of assembloids culture technology,scientists can assemble biomimetic organoids with more complex tissues in vitro,providing infinitely realistic models for the study of physiological and pathological processes of human tissue and organ.
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BACKGROUND:In the treatment of skin trauma with active repair,tissue engineering techniques are needed to generate new tissue to replace necrotic tissue.Skin scaffolds have a good application prospect in the field of wound repair.Skin scaffolds need to present three-dimensional porous structures with certain mechanical strength to meet the needs of cell proliferation and division.However,the mechanical strength of the currently used gelatin-based biomaterials is weak and cannot meet the requirements of the use of skin scaffolds. OBJECTIVE:To study the 3D printing process used in the preparation of tissue engineering skin scaffolds by gelatin/oxidized nanocellulose composites,and focus on the relationship between the porosity and mechanical strength of the scaffolds prepared under different process parameters. METHODS:Oxidized nanocellulose whiskers at 10%concentration were extracted from Humulus scandens and then compounded with 5%gelatin to obtain gelatin/oxidized nanocellulose composites.The elastic modulus of gelatin and gelatin/oxidized nanocellulose composite was determined.Skin scaffolds were prepared by 3D printing extrusion molding using gelatin/oxidized nanocellulose composite as the base material.Mechanical and rheological properties of the composite were tested to determine extrusion molding parameters(filling gap 1.5-2.5 mm,uniform distribution of 0.1 mm;air pressure of 160-200 kPa),and the skin scaffold with a three-dimensional porous structure was prepared.The compressive performance of the skin scaffold was tested and compared with the finite element analysis results.The relationship between the filling gap and the porosity and mechanical strength of the scaffold was demonstrated. RESULTS AND CONCLUSION:(1)The elastic modulus of 5%gelatin was increased by 8.84 times by adding 10%oxidized nanocellulose whisker.A gel filament with a diameter of 1 mm was obtained by extrusion at the air pressure of 160 kPa.When the filling gap increased from 1.5 mm to 2.5 mm,the theoretical porosity of the scaffold increased from 33%to 60%,but the compressive strength decreased from 230 000 Pa to 95 000 Pa.(2)These findings showed that the skin scaffold with theoretical porosity of 50%and elastic modulus of 160 000 Pa was prepared by using 2 mm filling gap.The scaffold had a clear three-dimensional porous structure.
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BACKGROUND:With the right bio-inks,3D printing can be used to create replacements for human tissues and organs that work inside the body.In recent years,3D printing technology has developed rapidly and has great application potential in regenerative medicine. OBJECTIVE:To introduce the types of bio-inks for 3D printing,and review the classification,application,advantages and disadvantages of bio-inks,as well as the future vision. METHODS:With"3D printing,biological ink,tissue engineering,hydrogel,synthetic material,cytoactive factor"as search terms,relevant articles published on PubMed and CNKI databases from 2000 to 2022 were searched by computer and finally 83 articles were included for review. RESULTS AND CONCLUSION:3D bioprinting technology has developed rapidly over the past few decades and has received great attention in various fields,including tissue engineering and biomedicine.Compared with the limitations of traditional biological scaffold manufacturing methods in terms of function and structure,3D printing can better simulate the complex structure of biological tissues and has appropriate mechanical,rheological and biological characteristics.Bio-ink is an essential part of 3D printing.Bioscaffolds produced by printing bio-ink prepared by biological materials have great scientific potential and clinical significance in tissue repair and regenerative medicine.The research of the materials itself is also getting more and more attention from experts.Bio-inks for 3D printing come in a variety of materials,from natural to synthetic,to aggregations of cells that do not require any additional biomaterials,and their usefulness in practical use varies.In the future,more and more bio-inks will be developed for tissue engineering.It is necessary to analyze the printability of bio-inks through sufficient experimental simulation and equipment testing to meet the actual medical needs.