Annals of 3D printed medicine最新文献

Electronic medical development focuses on creating an efficient rehabilitation device that will strengthen all surrounding muscles and enhance elbow performance. The elbow rehabilitation tool (ERT) provides sophisticated methods like exercise and motion analysis. The initiative is notable for its advanced assessment methods and adaptable training curricula, which offer users a thorough and successful therapeutic experience. The ERT includes elements like a stepper motor, variable resistor, steel wire, microcontroller, motor driver, and components created using a 3D printer. The experiment results show that the average systematic error percentage is about 82.857%, where seven healthy people have tested the ERT aged between 22 and 55 (five males and two females). The ERT also has achievement evaluation, which improves motivation and dedication to the recovery methods through an effective rehabilitation experience for users.

A β-TCP/Ti6Al4V composite scaffold with interconnected macro porous architecture was fabricated using Direct Ink Writing (DIW). Pluronic F-127 and de-ionized water was used as binder and solvent for ink preparation. The present work was carried out to study the rheological behavior of the composite bioceramic ink and to investigate DIW process parameters such as Ti6Al4V proportion, infill percentage and extrusion pressure. The Box-Behnken response surface methodology, ANOVA, sensitivity, desirability approach are used for the experimental, statistical and numerical optimization of the parameters suitable for DIW. The output responses such as dimensional error of the fabricated scaffold from the original dimensions and compressive strength are considered for multi-objective optimization. The result defined that the optimal values are solid loading 55 %v/v (40 %v/v of β-TCP, 15 %v/v of Ti6Al4V) and 45 %v/v of Pluronic gel, 98 % infill rate and 6.36 bar pressure. The dimensional error and compressive strength of the scaffold printed at the optimized conditions are found as 1.88 % and 19 MPa with macro and micro pores suitable for bone regeneration with satisfactory biocompatibility assed via MTT assay.

Background

In recent years, the treatment of wrist fractures has been the focus of numerous studies, particularly in the development of casts modeled on the patient's anatomy using additive manufacturing techniques. A 3D printed cast offers several advantages over traditional treatment methods, including washability, lightness, and ventilation.

Objective

This work introduces an automatic procedure for designing patient-specific wrist orthoses from a 3D scan of the arm using open-source mesh-processing libraries.

Methods

The procedure consists of seven steps that generate a customized orthosis model. Due to the absence of a single library capable of completing the entire modeling process, we defined the best execution strategy for each step and established a communication flow between the various blocks.

Results

The resulting orthosis comprises two halves, secured by three appropriately positioned bands and perforated with ventilation holes. The modeling procedure takes approximately 5 min to complete and was evaluated on 20 scans of arms of different shapes and sizes. The process proved to be fast, reliable, and suitable for direct use by medical personnel.

Conclusions

The developed automatic procedure for designing patient-specific wrist orthoses is efficient and effective, facilitating the use of 3D printed casts in medical practice.

Background

Three-dimensional (3D) printing has become increasingly affordable. Several research projects used 3D printing to create in vitro upper airways model. However, studies using a mainstream desktop 3D printer never performed geometric validation of their model. The aim of this study was to perform geometric validation of a pediatric upper airways model printed with a mainstream desktop 3D printer.

Methods

Head computerized tomography (CT) scan of a 10-month-old female underwent segmentation between airways and surrounding anatomical structures. Airways segmentation allowed their measurement for further comparison with printed model. Head segmentation enabled the creation of a 3D printable volume file. To proceed to the geometric validation of the head model, the latter underwent a CT scan. Similar segmentation work was performed on the printed model for comparison. Overlap proportion between the original infant volume and the printed model as well as an average Hausdorff distance were calculated after manual alignment between the original and printed model.

Results

Volumes were 12.31 cm³ and 12.32 cm³ for the pediatric and the printed model upper airways, respectively (0.08% difference). Dice coefficient of original and printed model was 0.92. The average Hausdorff distance was 0.21 mm.

Conclusion

Desktop mainstream 3D printers can generate pediatric upper airway model with a high dimensional accuracy, as evidenced by our comprehensive geometrical validation.

Our proposed method uses a three-dimensional (3D) measurement approach that focuses mainly on the lower jaw from basal, lateral, and frontal views applied to the volumetric skull model derived from a computed tomography (CT) of the head. Likewise, we discuss the geometrical features and clinical considerations involved in the 3D biomodeling of the surgical osteotomy. The workflow that allowed this virtual planning to be developed was composed of medical imaging processing software, data extraction software from images, and statistical software that allows the creation and generation of curve-fitting (nonlinear regression) graphs from data. Thirty-two (32) anatomical points were positioned, sixteen (16) measurements were taken, and two-dimensional (2D) sketches in three views (frontal, lateral, and inferior) were generated to overlap in a 3D environment, which informed the cutting of the desired bone segments. Implementing a nonlinear regression curve-fitting on the contours of the original jaws allowed optimal planning of the osteotomy. Desired cutting shapes were extrapolated for the front view by third-order equations, while for the side and bottom views, log-normal distribution curves and second-order polynomial curves were used, respectively. The reduction in the mandibular volume was between 6.55 and 10.27 %, with two of the most important measurements related to vertical reduction in the lateral views and the difference to determine gonion reduction.

Purpose

Advancements in 3D printing technology have led to a growing interest on its application in orthopedic surgery. In the context of shoulder and elbow surgery, studies on 3D printing mostly center on surgical guides for the placement of the glenoid component in shoulder arthroplasty, but applications in non-arthroplasty procedures remain unclear. This systematic review aims to evaluate and summarize the literature on the current applications and clinical outcomes of 3D Patient-Specific Instruments (3DPSI) in non-arthroplasty procedures. We expected to find a predominant focus on corrective osteotomies with positive clinical outcomes and minimal complications.

Methods

This systematic review adhered to PRISMA guidelines. Eligibility criteria included original research studies presenting primary data on 3DPSI for shoulder and elbow procedures. Exclusions were applied to studies exclusively reporting clinical data on 3DPSI for glenoid component placement in shoulder arthroplasty. A comprehensive literature search was conducted in PubMed/MEDLINE, Scopus, MedNar, Google Scholar, OAIster, and ProQuest Dissertations & Theses. Extracted data included study characteristics, 3DPSI development details, and clinical outcomes. Risk of bias was assessed using MINORS criteria.

Results

Out of 845 initially identified records, the final analysis included 20 studies. Regarding the application of 3DPSI, 35 % of the reports addressed cubitus varus osteotomy correction, 30 % focused on clavicle malunion or nonunion, and 15 % centered on corrective osteotomies for proximal humerus malunion. Risk of bias assessment using MINORS criteria demonstrated a mean score of 9.11 out of 16 for studies without a comparator group. Results across different pathologies revealed high patient-reported outcomes (PROs), good patient satisfaction, and minimal complications, which are presented.

Conclusion

In non-arthroplasty shoulder and elbow procedures, 3D Printed Patient-Specific Instrumentation have been mostly used for corrective osteotomies and demonstrates overall positive outcomes, low complications, and high patient satisfaction. Advancement in existing knowledge requires robust studies with larger cohorts and comparator groups.

Level of Evidence

Level IV.

Clinical Relevance

This study, summarizing existing data on 3D Patient-Specific Instruments (3DPSI) in non-arthroplasty shoulder and elbow procedures, offers guidance for future applications and research in this evolving field of orthopedic surgery.

Additive manufacturing techniques capable of fabricating biocompatible scaffolds with a given submicron/micron/supramicron structure are of growing interest for biomedical applications, including tissue engineering and tumor biology studies. Here, we propose antisolvent 3D printing and electrospinning techniques to obtain biopolymer scaffolds with different structural, mechanical, and surface properties to compare the cultivation patterns of glioblastoma cells. We found that human G01 cells, derived from human glioblastoma tumor tissue, were able to colonize the scaffolds in a time-dependent manner; the cells showed high viability as confirmed by colorimetric MTT assay, confocal fluorescence microscopy, and scanning electron microscopy data. Electrospun collagen scaffolds (low porosity, thin 2.75±0.22 μm fibers, low Young's modulus 0.076±0.033 MPa) provided monolayer-like growth of G01 glioblastoma cells with dense cell-cell contacts, while 3D-printed PLGA scaffolds (high porosity, thick ∼150 µm fibers, high Young's modulus 18±2 MPa) stimulated glioblastoma-specific spindle-like morphology. All scaffolds were non-toxic to cells and maintained cell growth for at least 2 weeks. The developed scaffolds could be further used for tumor research as a 3D model of glioblastoma in vitro or for tissue engineering of brain injury.

Porous scaffolds have evolved, allowing personalised 3D-printed structures that can improve tissue reconstruction. By using scaffolds with specific porosity, Poisson's ratio and stiffness, load-bearing tissues such as tibial reconstruction can be improved. Recent studies suggest the potential for negative Poisson's ratio ($-\upsilon$) meta-scaffolds in mimicking the behaviour of natural tissue, leading to improved healing and tissue reintegration. This study reveals a porous meta-scaffold that offers high $-\upsilon$ and can be personalised to match desired stiffness. By using laser powder bed fusion (L-PBF) of CoCrMo, a porous structure was created, characterised by its ability to achieve heightened $-\upsilon$. Prototype testing and numerical modelling unveiled a proxy-model capable of predicting and personalising the porosity, yield strength, elastic modulus, and $-\upsilon$ of the tibial meta-scaffold representing a novel contribution to the field. The surrogate model also aids characterising the impact of design variables such as of the scaffold on the key performance requirements of the tibial scaffold. This approach enables the fabrication of porous biomaterials with personalised properties, specifically suited for load-bearing tibial reconstruction. The resulting meta-scaffold offers $-\upsilon$ ranging from -0.16 to -0.38, porosity between 73.46% and 85.36%, yield strength of 30–80 MPa, and elastic modulus ranging from 8.6 to 22.6 GPa. The optimised architecture feature $-\upsilon$ of 0.223 and a targeted elastic modulus of 17.53 GPa, while also showcasing yield strength and porosity of 57.2 MPa and 76.35%, respectively. By combining 3D printing with tailored scaffolds, this study opens doors to mass customisation of improved load-bearing porous biomaterials that of negative Poisson's ratio and stiffness matching.

Introduction

The development of biomaterials and medical devices for burn wound treatment necessitates thorough investigation through in vitro/ex vivo models before transitioning to animal studies. Establishing a standardized and high-throughput burn wound model in ex vivo skin presents a considerable challenge. Our objective was to address this challenge by developing a practical and cost-effective 3D-printed burn wound tool capable of uniformly inducing burns in 12 skin samples simultaneously.

Material and methods

Utilizing Autodesk Inventor software, we designed a 3D model comprising a plate-base component (PBC) and a rod-base component (RBC). The design was exported as a Standard Triangulation Language (STL) file, processed through "Slicer" software to generate a G-code file tailored for 3D printing.

Results

The Rod-Base component underwent iterative design modifications to optimize weight, airflow, and material consumption, resulting in a final design featuring a unique star shape for enhanced airflow. Simultaneously, the Plate-Base component design evolved to enable easy and secure plate placement, demonstrating compatibility with 12-well plates. The average production time for the model was 14.5 h, with a production cost of approximately $20 (USD), covering printing material and steel rods.

Conclusion

In conclusion, this study provides valuable insights into the required equipment and software, empowering researchers to efficiently produce their accurate and cost-effective 3D-printed tool for controlled and reproducible burn wound creation in ex vivo viable skin tissues.

Three-dimensional (3D) bioprinting technology allows the production of porous structures with complex and varied geometries, which facilitates the development of equally dispersed cells and the orderly release of signal components. This is in contrast to the traditional methods used to produce tissue scaffolding. To date, 3D bioprinting has employed a range of cell-laden materials, including organic and synthetic polymers, to construct scaffolding systems and manufacture extracellular matrix (ECM). Still, there are several challenges in meeting the technical issues in bio-ink formulations, such as the printability of bio-inks, the customization of mechanical and biological properties in bio-implants, the guidance of cell activities in biomaterials, etc. The main objective of this article is to discuss the various strategies for preparing bio-inks to mimic native tissue's extracellular matrix environment. A discussion has also been conducted about the process parameters of bio-ink formulations and printing, structure requirements, and fabrication methods of durable bio-scaffolds. The present study also reviews various 3D-printing techniques. Conclusively, the challenges and potential paths for smart bioink/scaffolds have been outlined for tissue regeneration.