Annals of 3D printed medicine最新文献

Background

Sesamoidectomy can be associated with multiple complications secondary to loss of the intrinsic function of the excised sesamoid. We sought to mitigate these complications by preserving sesamoid function with a total sesamoid replacement (TSR) in lieu of sesamoidectomy.

Method

Patient specific 3D printed TSR implants were designed and implanted for three patients who had exhaustively failed conservative measures. Follow up ranges from 7-36 months during which we evaluated for complications, symptom resolution, and patient satisfaction.

Result

All patients had complete resolution of pain between 3.5-12 months postop and have remained satisfied with their outcome. No evidence of the aforementioned complications was observed.

Conclusion

TSR may represent a viable alternative treatment option for most cases in which sesamoidectomy would otherwise be considered.

Level of evidence

IV, case series.

Additive manufacturing has developed rapidly in recent years and has many useful applications in the clinical field. In particular, cranio-maxillo-facial (CMF) surgery requires high precision, which can be obtained with 3D printed patient-specific surgical guides and anatomical models. Among the many different printing options, selective laser sintering (SLS) seems to be rarely used in point-of-care applications, considering its apparent characteristics.

This article examines the advantages and disadvantages of SLS printers for CMF point-of-care (PoC) by reviewing the literature and comparing in-house printed SLS and stereolithography (SLA) prints.

The investigation showed that the easily sterilizable and robust materials processed by SLS printing are well suited for CMF surgical guides and have clear advantages over SLA parts.

Some barriers to the use of SLS printers in PoC are likely to be the slightly higher complexity and cost.

However, these will decrease as 3D printing technology advances and surgeon acceptance increases, making SLS a practical PoC tool.

Objective

Non-neurosurgeons in regional and rural hospitals may be required to operate on patients presenting with a traumatic brain injury where timely transfer to a tertiary hospital is not possible. Confidence and experience can vary significantly due to limited access to hands-on training. Increasing availability to advanced 3D printed models opens new opportunities to provide accurate head models suitable for this purpose. This study evaluated the experience of regional clinicians and nurses following a neurotrauma workshop where 3D printed head models were used to provide training in burr hole and craniotomy procedures.

Methods

A neurotrauma seminar and workshop was hosted at the Sunshine Coast Health Institute, in the state of Queensland, Australia. The workshop component allowed 26 local clinicians and nurses to gain hands-on experience with a 3D printed head model, guided by neurosurgeons from the closest tertiary hospital. Following training, participants completed a short survey.

Results

Prior to this workshop, most participants had never performed a burr hole (58 %, n=15) or interacted with a 3D printed model (69 %, n=18). Overall, most participants indicated that the 3D printed model performed better (58 %, n=15) and much better (15 %, n=4) than their expectations. 81 % (n=21) left the workshop with improved confidence in performing burr hole and craniotomy procedures. Despite some melting of the plastic, 96 % (n=25) of participants would recommend this model to their colleagues.

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.