3D Printing in Medicine
EISSN : 2365-6271
Published by: Springer Science and Business Media LLC (10.1186)
Total articles ≅ 106
Latest articles in this journal
3D Printing in Medicine, Volume 7, pp 1-1; doi:10.1186/s41205-021-00109-5
3D Printing in Medicine, Volume 7, pp 1-11; doi:10.1186/s41205-021-00108-6
Background Subcapital osteotomy by means of surgical hip dislocation is a treatment approach offered for moderate-to-severe cases of Slipped Capital Femoral Epiphysis (SCFE). This procedure is demanding, highly dependent on the surgeon’s experience, and requires considerable radiation exposure for monitoring and securing the spatial alignment of the femoral head. We propose the use of individualized drill guides as an accurate method for placing K-wires during subcapital correction osteotomies in SCFE patients. Methods Five CT scans of the hip joint from otherwise healthy patients with moderate-to-severe SCFE were selected (ages 11–14). Three dimensional models of each patient’s femur were reconstructed by manual segmentation and physically replicated using additive manufacturing techniques. Five orthopaedic surgeons virtually identified the optimal entry point and direction of the two threaded wires for each case. 3D printed drill guides were designed specific to each surgical plan, with one side shaped to fit the patient’s bone and the other side containing holes to guide the surgical drill. Each surgeon performed three guided (using the drill guides) and three conventional (freehand) simulated procedures on each case. Each femur model was laser scanned and digitally matched to the preoperative model for evaluation of entry points and wire angulations. We compared wire entry point, wire angulation, procedure time and number of x-rays between guided and freehand simulated surgeries. Results The guided group (1.4 ± 0.9 mm; 2.5° ± 1.4°) was significantly more accurate than the freehand group (5.8 ± 3.2 mm; 5.3° ± 4.4°) for wire entry location and angulation (p < 0.001). Guided surgeries required significantly less drilling time and intraoperative x-rays (90.5 ± 42.2 s, 3 ± 1 scans) compared to the conventional surgeries (246.8 ± 122.1 s, 14 ± 5 scans) (p < 0.001). Conclusions We conclude that CT-based preoperative planning and intraoperative navigation using individualized drill guides allow for improved accuracy of wires, reduced operative time and less radiation exposure in simulated hips. Clinical relevance This preliminary study shows promising results, suggesting potential direct benefits to SCFE patients by necessitating less time under anesthesia and less intra-operative radiation exposure to patients, and increasing surgical accuracy.
3D Printing in Medicine, Volume 7; doi:10.1186/s41205-021-00107-7
Background Patient specific three-dimensional (3D) models can be derived from two-dimensional medical images, such as magnetic resonance (MR) images. 3D models have been shown to improve anatomical comprehension by providing more accurate assessments of anatomical volumes and better perspectives of structural orientations relative to adjacent structures. The clinical benefit of using patient specific 3D printed models have been highlighted in the fields of orthopaedics, cardiothoracics, and neurosurgery for the purpose of pre-surgical planning. However, reports on the clinical use of 3D printed models in the field of gynecology are limited. Main text This article aims to provide a brief overview of the principles of 3D printing and the steps required to derive patient-specific, anatomically accurate 3D printed models of gynecologic anatomy from MR images. Examples of 3D printed models for uterine fibroids and endometriosis are presented as well as a discussion on the barriers to clinical uptake and the future directions for 3D printing in the field of gynecological surgery. Conclusion Successful gynecologic surgery requires a thorough understanding of the patient’s anatomy and burden of disease. Future use of patient specific 3D printed models is encouraged so the clinical benefit can be better understood and evidence to support their use in standard of care can be provided.
3D Printing in Medicine, Volume 7, pp 1-10; doi:10.1186/s41205-021-00106-8
Background The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic during the fall of 2019 and into the spring of 2020 has led to an increased demand of disposable N95 respirators and other types of personal protective equipment (PPE) as a way to prevent virus spread and help ensure the safety of healthcare workers. The sudden demand led to rapid modification, development, and dissemination of 3D printed PPE. The goal of this study was to determine the inherent sterility and re-sterilizing ability of 3D printed PPE in order to provide sterile equipment to the healthcare field and the general public. Methods Samples of polylactic acid (PLA), thermoplastic polyurethane (TPU) (infill-based designs) and polypropylene (single-wall hollow design) were 3D printed. Samples were inoculated with E. coli for 24 h and then sanitized using various chemical solutions or heat-based methods. The samples were then incubated for 24- or 72-h in sterile LB medium at 37°C, and bacterial growth was measured by optical density at 600nm. Statistical analysis was conducted using GraphPad Prism v8.2.1. Results Significant bacterial growth was observed in all PLA and TPU based samples following re-sterilization, regardless of the methods used when compared to controls (p < 0.05). The single-walled hollow polypropylene design was not only sterile following printing, but was also able to undergo re-sanitization following bacterial inoculation, with no significant bacterial growth (p > 0.05) observed regardless of sanitization method used. Conclusion The cost effectiveness, ease of sanitization, and reusability of 3D printed PPE, using our novel single-walled polypropylene design can help meet increased demands of PPE for healthcare workers and the general public that are needed to help decrease the viral transmission of the coronavirus disease of 2019 (COVID-19) pandemic. 3D printing also has the potential to lead to the creation and production of other sterile material items for the healthcare industry in the future. The ability to re-sterilize 3D printed PPE, as our design shows, would also contribute less to the increase in biomedical waste (BMW) being experienced by COVID-19.
3D Printing in Medicine, Volume 7, pp 1-9; doi:10.1186/s41205-021-00105-9
Purpose Training in retrograde intrarenal surgery for the treatment of renal stone disease is a challenging task due to the unique complexity of the procedure. This study introduces a series of 3D printed models of upper urinary tract and stones designed to improve the training process. Methods Six different models of upper urinary tract were algorithmically isolated, digitally optimized and 3D printed from real-life cases. Soft and hard stones in different sizes were produced from 3D printed moulds. The models were fitted onto a commercially available part-task trainer and tested for retrograde intrarenal surgery. Results Each step of the procedure was simulated with extraordinary resemblance to real-life cases. The unique anatomical intricacy of each model and type of stones allowed us to reproduce surgeries of increasing difficulty. As the case-load required to achieve proficiency in retrograde intrarenal surgery is high, benchtop simulation could be integrated in training programs to reach good outcomes and low complication rates faster. Our models match incredible anatomical resemblance with low production cost and high reusability. Validation studies and objective skills assessment during simulations would allow comparison with other available benchtop trainers and the design of stepwise training programs. Conclusions 3D printing is gaining a significant importance in surgical training. Our 3D printed models of the upper urinary tract might represent a risk-free training option to hasten the achievement of proficiency in endourology.
3D Printing in Medicine, Volume 7, pp 1-7; doi:10.1186/s41205-021-00104-w
Background Percutaneous tracheostomy is frequently performed in intensive care units in patients who require prolonged mechanical ventilation. The first crucial step for the physician in these procedures is the precise needle insertion into the trachea. The primary aim of this technical note was to test the new filament and share our experiences in the implementation of the new device. The secondary aim was to show how a physician with basic training in computer-aided design and three-dimensional (3D) printing could independently create useful devices for clinical practice. Methods To simplify this referred clinical procedure and increase its safety, 3D printing and a new medical filament were used to develop a new translaryngeal Tracheostomy Needle Introducer (tTNI) for use in conjunction with the Fantoni’s method of percutaneous tracheostomy. The tTNI is composed of three parts: a support to fit on the rigid endotracheal tube of the Fantoni kit, an external particular shaped arm, and an introducer for the needle. The latest version of the device used a new filament based on a polyester matrix certified for skin contact that was sterilizable in a standard autoclave. Post-printing, minor technical interventions were required to correct small material deformities. Conclusions Our experiences with the thread and the technical features of the material were reported herein in conjunction with some suggestions on how to solve the most frequently encountered problems. The 3D printing technique allows physicians to directly manage the prototyping process of new medical devices, making this process completely independent. The speed of the prototyping process and the testing of each piece allow faster creation of a prototype than with traditional industrial methods. Finally, the new biomedical filaments offer endless possibilities of creation and modelling.
3D Printing in Medicine, Volume 7, pp 1-16; doi:10.1186/s41205-021-00100-0
Objective This study reports on a new method for the development of multi-color and multi-material realistic Knee Joint anatomical models with unique features. In particular, the design of a fibers matrix structure that mimics the soft tissue anatomy. Methods Various Computer-Aided Design (CAD) systems and the PolyJet 3D printing were used in the fabrication of three anatomical models wherein fibers matrix structure is mimicked: (i) Anterior cruciate ligament reconstruction (ACL-R) model used in the previous study. (ii) ACL-R model, incorporating orientations, directions, locations, and dimensions of the tunnels, as well as a custom-made surgical guide (SG) for avoiding graft tunnel length mismatch. (iii) Total knee arthroplasty (TKA) model, including custom-made implants. Before models 3D printing, uni-axial tensile tests were conducted to obtain the mechanical behaviors for individual No. 1 (A60-A50), No. 2 (A50-A50), No. 3 (A50-A40), and No. 4 (A70-A60) soft tissue-mimicking polymers. Each material combination represents different shore-hardness values between fiber and matrix respectively. Results We correlated the pattern of stress-strain curves in the elastic region, stiffness, and elastic modulus of proposed combinations with published literature. Accordingly, material combinations No. 1 and No. 4 with elastic modules of 0.76-1.82 MPa were chosen for the soft tissues 3D printing. Finally, 3D printing Knee Joint models were tested manually simulating 50 flexo-extension cycles without presenting ruptures. Conclusion The proposed anatomical models offer a diverse range of applications. These may be considered as an alternative to replacing cadaver specimens for medical training, pre-operative planning, research and education purposes, and predictive models validation. The soft tissue anatomy-mimicking materials are strong enough to withstand the stretching during the flexo-extension. The methodology reported for the design of the fiber-matrix structure might be considered as a start to develop new patterns and typologies that may mimic soft tissues.
3D Printing in Medicine, Volume 7, pp 1-12; doi:10.1186/s41205-021-00103-x
Background Three-dimensional (3D)-printed saw guides are frequently used to optimize osteotomy results and are usually designed based on computed tomography (CT), despite the radiation burden, as radiation-less alternatives like magnetic resonance imaging (MRI) have inferior bone visualization capabilities. This study investigated the usability of MR-based synthetic-CT (sCT), a novel radiation-less bone visualization technique for 3D planning and design of patient-specific saw guides. Methods Eight human cadaveric lower arms (mean age: 78y) received MRI and CT scans as well as high-resolution micro-CT. From the MRI scans, sCT were generated using a conditional generative adversarial network. Digital 3D bone surface models based on the sCT and general CT were compared to the surface model from the micro-CT that was used as ground truth for image resolution. From both the sCT and CT digital bone models saw guides were designed and 3D-printed in nylon for one proximal and one distal bone position for each radius and ulna. Six blinded observers placed these saw guides as accurately as possible on dissected bones. The position of each guide was assessed by optical 3D-scanning of each bone with positioned saw guide and compared to the preplanning. Eight placement errors were evaluated: three translational errors (along each axis), three rotational errors (around each axis), a total translation (∆T) and a total rotation error (∆R). Results Surface models derived from micro-CT were on average smaller than sCT and CT-based models with average differences of 0.27 ± 0.30 mm for sCT and 0.24 ± 0.12 mm for CT. No statistically significant positioning differences on the bones were found between sCT- and CT-based saw guides for any axis specific translational or rotational errors nor between the ∆T (p = .284) and ∆R (p = .216). On Bland-Altman plots, the ∆T and ∆R limits of agreement (LoA) were within the inter-observer variability LoA. Conclusions This research showed a similar error for sCT and CT digital surface models when comparing to ground truth micro-CT models. Additionally, the saw guide study showed equivalent CT- and sCT-based saw guide placement errors. Therefore, MRI-based synthetic CT is a promising radiation-less alternative to CT for the creation of patient-specific osteotomy surgical saw guides.
3D Printing in Medicine, Volume 7, pp 1-14; doi:10.1186/s41205-021-00101-z
Background The integration of 3D printing technology in hospitals is evolving toward production models such as point-of-care manufacturing. This study aims to present the results of the integration of 3D printing technology in a manufacturing university hospital. Methods Observational, descriptive, retrospective, and monocentric study of 907 instances of 3D printing from November 2015 to March 2020. Variables such as product type, utility, time, or manufacturing materials were analyzed. Results Orthopedic Surgery and Traumatology, Oral and Maxillofacial Surgery, and Gynecology and Obstetrics are the medical specialties that have manufactured the largest number of processes. Working and printing time, as well as the amount of printing material, is different for different types of products and input data. The most common printing material was polylactic acid, although biocompatible resin was introduced to produce surgical guides. In addition, the hospital has worked on the co-design of custom-made implants with manufacturing companies and has also participated in tissue bio-printing projects. Conclusions The integration of 3D printing in a university hospital allows identifying the conceptual evolution to “point-of-care manufacturing.”
3D Printing in Medicine, Volume 7, pp 1-10; doi:10.1186/s41205-021-00102-y
Rationale and objectives Three-dimensional (3D) printing has been utilized as a means of producing high-quality simulation models for trainees in procedure-intensive or surgical subspecialties. However, less is known about its role for trainee education within interventional radiology (IR). Thus, the purpose of this review was to assess the state of current literature regarding the use of 3D printed simulation models in IR procedural simulation experiences. Materials and methods A literature query was conducted through April 2020 for articles discussing three-dimensional printing for simulations in PubMed, Embase, CINAHL, Web of Science, and the Cochrane library databases using key terms relating to 3D printing, radiology, simulation, training, and interventional radiology. Results We identified a scarcity of published sources, 4 total articles, that appraised the use of three-dimensional printing for simulation training in IR. While trainee feedback is generally supportive of the use of three-dimensional printing within the field, current applications utilizing 3D printed models are heterogeneous, reflecting a lack of best practices standards in the realm of medical education. Conclusions Presently available literature endorses the use of three-dimensional printing within interventional radiology as a teaching tool. Literature documenting the benefits of 3D printed models for IR simulation has the potential to expand within the field, as it offers a straightforward, sustainable, and reproducible means for hands-on training that ought to be standardized.