3D-Customized Guiding Template for Posterior Fixation in Complex Atlantoaxial Instability—Preliminary Experiences of National Cheng Kung University Hospital

Objective Atlantoaxial fixation is technically demanding and challenging, especially in cases with anatomical abnormality. The purpose of this study is to report the effectiveness of the three-dimensional (3D)-customized guiding template for placement of C1 and C2 screws in cases with abnormalities. Method Two patients with anatomical abnormality and one without were included. The preoperative computed tomography (CT) image was analyzed using our software. The entry point, trajectory, and depth of the screws were designed based on these images. Templates with screw guiding cylinders and cervical spine model were created. In operation, guiding templates were applied directly to the laminae. Drilling, tapping, and screwing were performed through the cylinders. To evaluate the accuracy, deviation of the screw axis from the preplanned trajectory was measured on postoperative CT. A classification system was taking to evaluate the pedicle screw insertion. Results In complex cases, one of C2 screws has grade 2 deviation, and two has grade 1. There was no deviation in screws of C1. All patients achieved symptoms free after 6 months follow-up. Conclusion Although 3D-printed template for atlantoaxial fixation still has limitation in complex cases, it has been proved usefulness and makes the most difficult and dangerous spinal posterior fixation easy to achieve.

Download Full-text

Three-Dimensional-Printed Drill Guides for Occipitothoracic Fusion in a Pediatric Patient With Occipitocervical Instability

Operative Neurosurgery ◽

10.1093/ons/opab060 ◽

2021 ◽

Author(s):

Peter A J Pijpker ◽

Jos M A Kuijlen ◽

Bart L Kaptein ◽

Willem Pondaag

Keyword(s):

Spinal Cord ◽

Three Dimensional ◽

Pedicle Screws ◽

Cord Compression ◽

Occipital Bone ◽

The Novel ◽

3D Technology ◽

Screw Insertion ◽

3D Printed ◽

Keel Plate

Abstract BACKGROUND Pediatric occipitothoracic fusion can be challenging because of small size pedicles and thin occipital bone. Three-dimensional (3D) printing technology can help with accurate screw insertion but has not been described for occipital keel plate positioning so far. OBJECTIVE To describe the novel use of 3D technology to position occipital keel plates during pediatric occipitothoracic fixation. METHODS A young boy with segmental spinal dysgenesis presented with asymmetrical pyramidal paresis in all limbs. Developmental abnormities of the cervical spine caused a thinned spinal cord, and because of progressive spinal cord compression, surgical intervention by means of occipitothoracic fixation was indicated at the age of 3 yr. Because of the small-size pedicles and thin occipital bone, the pedicle screws and occipital plates were planned meticulously using 3D virtual surgical planning technology. The rods were virtually bent in order to properly align with the planned screws. By means of 3D-printed guides, the surgical plan was transferred to the operating theater. For the occipital bone, a novel guide concept was developed, aiming for screw positions at maximal bone thickness. RESULTS The postoperative course was uneventful, and radiographs showed good cervical alignment. After superimposing the virtual plan with the intraoperative acquired computed tomography, it was confirmed that the occipital plate positions matched the virtual plan and that pedicle screws were accurately inserted without signs of breach. CONCLUSION The use of 3D technology has greatly facilitated the performance of the occipitothoracic fixation and could, in the future, contribute to safer pediatric spinal fixation procedures.

Download Full-text

Effect of 3D-Printed Models on Cadaveric Dissection in Temporal Bone Training

OTO Open ◽

10.1177/2473974x211065012 ◽

2021 ◽

Vol 5 (4) ◽

pp. 2473974X2110650

Author(s):

Andreas Frithioff ◽

Martin Frendø ◽

Kenneth Weiss ◽

Søren Foghsgaard ◽

David Bue Pedersen ◽

...

Keyword(s):

Temporal Bone ◽

Assessment Tool ◽

Three Dimensional ◽

University Hospital ◽

Cadaver Dissection ◽

Cadaveric Dissection ◽

Vr Training ◽

3D Printed ◽

Temporal Bones ◽

Simulation Center

Objective Mastoidectomy is a cornerstone in the surgical management of middle and inner ear diseases. Unfortunately, training is challenged by insufficient access to human cadavers. Three-dimensional (3D) printing of temporal bones could alleviate this problem, but evidence on their educational effectiveness is lacking. It is largely unknown whether training on 3D-printed temporal bones improves mastoidectomy performance, including on cadavers, and how this training compares with virtual reality (VR) simulation. To address this knowledge gap, this study investigated whether training on 3D-printed temporal bones improves cadaveric dissection performance, and it compared this training with the already-established VR simulation. Study Design Prospective cohort study of an educational intervention. Setting Tertiary university hospital, cadaver dissection laboratory, and simulation center in Copenhagen, Denmark. Methods Eighteen otorhinolaryngology residents (intervention) attending the national temporal bone dissection course received 3 hours of mastoidectomy training on 3D-printed temporal bones. Posttraining cadaver mastoidectomy performances were rated by 3 experts using a validated assessment tool and compared with those of 66 previous course participants (control) who had received time-equivalent VR training prior to dissection. Results The intervention cohort outperformed the controls during cadaver dissection by 29% ( P < .001); their performances were largely similar across training modalities but remained at a modest level (~50% of the maximum score). Conclusion Mastoidectomy skills improved from training on 3D-printed temporal bone and seemingly more so than on time-equivalent VR simulation. Importantly, these skills transferred to cadaveric dissection. Training on 3D-printed temporal bones can effectively supplement cadaver training when learning mastoidectomy.

Download Full-text

Use of Three-dimensional Printing in the Development of Optimal Cardiac CT Scanning Protocols

Current Medical Imaging Formerly Current Medical Imaging Reviews ◽

10.2174/1573405616666200124124140 ◽

2020 ◽

Vol 16 (8) ◽

pp. 967-977

Author(s):

Zhonghua Sun

Keyword(s):

Cardiovascular Disease ◽

Cardiac Computed Tomography ◽

Three Dimensional ◽

Ct Scanning ◽

Aortic Diseases ◽

Clinical Value ◽

Three Dimensional Printing ◽

Doctor Patient Communication ◽

Medical Education And Training ◽

3D Printed

Three-dimensional (3D) printing is increasingly used in medical applications with most of the studies focusing on its applications in medical education and training, pre-surgical planning and simulation, and doctor-patient communication. An emerging area of utilising 3D printed models lies in the development of cardiac computed tomography (CT) protocols for visualisation and detection of cardiovascular disease. Specifically, 3D printed heart and cardiovascular models have shown potential value in the evaluation of coronary plaques and coronary stents, aortic diseases and detection of pulmonary embolism. This review article provides an overview of the clinical value of 3D printed models in these areas with regard to the development of optimal CT scanning protocols for both diagnostic evaluation of cardiovascular disease and reduction of radiation dose. The expected outcomes are to encourage further research towards this direction.

Download Full-text

Investigation of the Static Behavior and Failure Mechanisms of a 3D Printed Bio-Based Sandwich with Auxetic Core

International Journal of Applied Mechanics ◽

10.1142/s1758825120500519 ◽

2020 ◽

Vol 12 (05) ◽

pp. 2050051

Author(s):

Khawla Essassi ◽

Jean-Luc Rebiere ◽

Abderrahim El Mahi ◽

Mohamed Amine Ben Souf ◽

Anas Bouguecha ◽

...

Keyword(s):

Failure Mechanisms ◽

Three Dimensional ◽

Acoustic Emissions ◽

Shear Stiffness ◽

Tensile Tests ◽

Sandwich Composite ◽

Static Behavior ◽

Flax Fibers ◽

Data Points ◽

3D Printed

In this research contribution, the static behavior and failure mechanisms are developed for a three-dimensional (3D) printed dogbone, auxetic structure and sandwich composite using acoustic emissions (AEs). The skins, core and whole sandwich are manufactured using the same bio-based material which is polylactic acid reinforced with micro-flax fibers. Tensile tests are conducted on the skins and the core while bending tests are conducted on the sandwich composite. Those tests are carried out on four different auxetic densities in order to investigate their effect on the mechanical and damage properties of the materials. To monitor the invisible damage and damage propagation, a highly sensitive AE testing method is used. It is found that the sandwich with high core density displays advanced mechanical properties in terms of bending stiffness, shear stiffness, facing bending stress and core shear stress. In addition, the AE data points during testing present an amplitude range of 40–85[Formula: see text]dB that characterizes visible and invisible damage up to failure.

Download Full-text

Midface Reconstruction: Planning and Outcome

Indian Journal of Plastic Surgery ◽

10.1055/s-0040-1721870 ◽

2020 ◽

Vol 53 (03) ◽

pp. 324-334

Author(s):

Gautam Biswas

Keyword(s):

Digital Imaging ◽

3D Structure ◽

Three Dimensional ◽

The Past ◽

Complex Anatomy ◽

Osseointegrated Implants ◽

Low Profile ◽

3D Printed ◽

Midface Reconstruction ◽

Reconstruction Planning

Abstract Reconstruction of the complex anatomy and aesthetics of the midface is often a challenge. A careful understanding of this three-dimensional (3D) structure is necessary. Anticipating the extent of excision and its planning following oncological resections is critical.In the past over two decades, with the advances in microsurgical procedures, contributions toward the reconstruction of this area have generated interest. Planning using digital imaging, 3D printed models, osseointegrated implants, and low-profile plates, has favorably impacted the outcome. However, there are still controversies in the management: to use single composite tissues versus multiple tissues; implants versus autografts; vascularized versus nonvascularized bone; prosthesis versus reconstruction.This article explores the present available options in maxillary reconstruction and outlines the approach in the management garnered from past publications and experiences.

Download Full-text

Recurrent contracted sockets treated with personalized, three-dimensionally printed conformers and buccal grafts

European Journal of Ophthalmology ◽

10.1177/11206721211000013 ◽

2021 ◽

pp. 112067212110000

Author(s):

Annabel LW Groot ◽

Jelmer S Remmers ◽

Roel JHM Kloos ◽

Peerooz Saeed ◽

Dyonne T Hartong

Keyword(s):

Three Dimensional ◽

Case Series ◽

Secondary Outcome ◽

Retrospective Case ◽

Upper Eyelid ◽

Ocular Prosthesis ◽

Buccal Mucosal Graft ◽

Custom Made ◽

3D Printed

Purpose: Recurrent contracted sockets are complex situations where previous surgeries have failed, disabling the wear of an ocular prosthesis. A combined method of surgery and long-term fixation using custom-made, three-dimensional (3D) printed conformers is evaluated. Methods: Retrospective case series of nine patients with recurrent excessive socket contraction and inability to wear a prosthesis, caused by chemical burns ( n = 3), fireworks ( n = 3), trauma ( n = 2) and enucleation and radiotherapy at childhood due to optic nerve glioma ( n = 1) with three average previous socket surgeries (range 2–6). Treatment consisted of a buccal mucosal graft and personalized 3D-printed conformer designed to be fixated to the periosteum and tarsal plates for minimal 2 months. Primary outcome was the retention of an ocular prosthesis. Secondary outcome was the need for additional surgeries. Results: Outcomes were measured at final follow-up between 7 and 36 months postoperatively (mean 20 months). Eight cases were able to wear an ocular prosthesis after 2 months. Three cases initially treated for only the upper or only the lower fornix needed subsequent surgery for the opposite fornix for functional reasons. Two cases had later surgery for cosmetic improvement of upper eyelid position. Despite pre-existing lid abnormalities (scar, entropion, lash deficiency), cosmetic outcome was judged highly acceptable in six cases because of symmetric contour and volume, and reasonably acceptable in the remaining two. Conclusions: Buccal mucosal transplant fixated with a personalized 3D-designed conformer enables retention of a well-fitted ocular prosthesis in previously failed socket surgeries. Initial treatment of both upper and lower fornices is recommended to avoid subsequent surgeries for functional reasons.

Download Full-text

Three-dimensional printing for heart diseases: clinical application review

Bio-Design and Manufacturing ◽

10.1007/s42242-021-00125-8 ◽

2021 ◽

Author(s):

Yanyan Ma ◽

Peng Ding ◽

Lanlan Li ◽

Yang Liu ◽

Ping Jin ◽

...

Keyword(s):

3D Printing ◽

Clinical Application ◽

Heart Diseases ◽

Three Dimensional ◽

Convincing Evidence ◽

Surgical Interventions ◽

Three Dimensional Printing ◽

Complex Anatomy ◽

Precise Understanding ◽

3D Printed

AbstractHeart diseases remain the top threat to human health, and the treatment of heart diseases changes with each passing day. Convincing evidence shows that three-dimensional (3D) printing allows for a more precise understanding of the complex anatomy associated with various heart diseases. In addition, 3D-printed models of cardiac diseases may serve as effective educational tools and for hands-on simulation of surgical interventions. We introduce examples of the clinical applications of different types of 3D printing based on specific cases and clinical application scenarios of 3D printing in treating heart diseases. We also discuss the limitations and clinically unmet needs of 3D printing in this context.

Download Full-text

Two-Dimensional Visualization of the Three-Dimensional Planned Sacroiliac Screw Corridor with the Slice Fusion Method

Journal of Clinical Medicine ◽

10.3390/jcm10020184 ◽

2021 ◽

Vol 10 (2) ◽

pp. 184

Author(s):

Maximilian Kerschbaum ◽

Siegmund Lang ◽

Florian Baumann ◽

Volker Alt ◽

Michael Worlicek

Keyword(s):

Pelvic Ring ◽

Three Dimensional ◽

Fusion Method ◽

Two Dimensional ◽

Posterior Pelvic Ring ◽

Simple Method ◽

Sacroiliac Screw ◽

Screw Insertion ◽

Multiplanar Reconstructions ◽

Screw Position

Insertion of sacro-iliac (SI) screws for stabilization of the posterior pelvic ring without intraoperative navigation or three-dimensional imaging can be challenging. The aim of this study was to develop a simple method to visualize the ideal SI screw corridor, on lateral two-dimensional images, corresponding to the lateral fluoroscopic view, used intraoperatively while screw insertion, to prevent neurovascular injury. We used multiplanar reconstructions of pre- and postoperative computed tomography scans (CT) to determine the position of the SI corridor. Then, we processed the dataset into a lateral two-dimensional slice fusion image (SFI) matching head and tip of the screw. Comparison of the preoperative SFI planning and the screw position in the postoperative SFI showed reproducible results. In conclusion, the slice fusion method is a simple technique for translation of three-dimensional planned SI screw positioning into a two-dimensional strict lateral fluoroscopic-like view.

Download Full-text

Development of three-dimensional printing filaments based on poly(lactic acid)/hydroxyapatite composites with potential for tissue engineering

Journal of Composite Materials ◽

10.1177/0021998320988568 ◽

2021 ◽

pp. 002199832098856

Author(s):

Marcela Piassi Bernardo ◽

Bruna Cristina Rodrigues da Silva ◽

Luiz Henrique Capparelli Mattoso

Keyword(s):

Tissue Engineering ◽

Lactic Acid ◽

Fused Deposition Modeling ◽

Three Dimensional ◽

Poly Lactic Acid ◽

Scanning Calorimetry ◽

Three Dimensional Printing ◽

Fused Deposition ◽

Deposition Modeling ◽

3D Printed

Injured bone tissues can be healed with scaffolds, which could be manufactured using the fused deposition modeling (FDM) strategy. Poly(lactic acid) (PLA) is one of the most biocompatible polymers suitable for FDM, while hydroxyapatite (HA) could improve the bioactivity of scaffold due to its chemical composition. Therefore, the combination of PLA/HA can create composite filaments adequate for FDM and with high osteoconductive and osteointegration potentials. In this work, we proposed a different approache to improve the potential bioactivity of 3D printed scaffolds for bone tissue engineering by increasing the HA loading (20-30%) in the PLA composite filaments. Two routes were investigated regarding the use of solvents in the filament production. To assess the suitability of the FDM-3D printing process, and the influence of the HA content on the polymer matrix, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were performed. The HA phase content of the composite filaments agreed with the initial composite proportions. The wettability of the 3D printed scaffolds was also increased. It was shown a greener route for obtaining composite filaments that generate scaffolds with properties similar to those obtained by the solvent casting, with high HA content and great potential to be used as a bone graft.

Download Full-text

Three-Dimensional Printing of Hydroxyapatite Composites for Biomedical Application

Crystals ◽

10.3390/cryst11040353 ◽

2021 ◽

Vol 11 (4) ◽

pp. 353

Author(s):

Yanting Han ◽

Qianqian Wei ◽

Pengbo Chang ◽

Kehui Hu ◽

Oseweuba Valentine Okoro ◽

...

Keyword(s):

Tissue Engineering ◽

3D Printing ◽

Biomedical Application ◽

Three Dimensional ◽

Antibacterial Properties ◽

Natural Polymers ◽

Three Dimensional Printing ◽

3D Printed ◽

Dental Applications ◽

Hard Tissue Engineering

Hydroxyapatite (HA) and HA-based nanocomposites have been recognized as ideal biomaterials in hard tissue engineering because of their compositional similarity to bioapatite. However, the traditional HA-based nanocomposites fabrication techniques still limit the utilization of HA in bone, cartilage, dental, applications, and other fields. In recent years, three-dimensional (3D) printing has been shown to provide a fast, precise, controllable, and scalable fabrication approach for the synthesis of HA-based scaffolds. This review therefore explores available 3D printing technologies for the preparation of porous HA-based nanocomposites. In the present review, different 3D printed HA-based scaffolds composited with natural polymers and/or synthetic polymers are discussed. Furthermore, the desired properties of HA-based composites via 3D printing such as porosity, mechanical properties, biodegradability, and antibacterial properties are extensively explored. Lastly, the applications and the next generation of HA-based nanocomposites for tissue engineering are discussed.

Download Full-text