Annals of 3D printed medicine最新文献

In this technical note we report a case where 3D-printing aided the reassembly of skull fragments in a homicide with severe tampering of the bones. A young male was shot, the body was incinerated and crushed with garden tools resulting in hundreds of brittle, calcine bone fragments from the skull. An antemortem computed tomography (CT)-scan of the skull was available from a previous assault of the victim. To aid the process of reassembly we used the antemortem CT-data to develop a 3D fixture-grid of the cranial cavity. The 3D grid was utilized as an anatomically correct template for bone reconstruction. This novel technique was based solely on open-source software including 3D Slicer and Blender and could have the potential to aid similar cases.

Extrusion-based 3D bioprinting (EBBP) prints tissues, including nerve guide conduits, bone tissue engineering, skin tissue repair, cartilage repair, and muscle repair. The EBBP demands optimized parameters for obtaining good printability and cell viability. However, finding optimal process parameters is always essential for the researcher. The biological, mechanical, and rheological parameters all together need to be evaluated to enhance the printability of tissue. A degree of simplicity may be required to interpret each parameter's effect. However, overcoming complexity with a multiparameter is quite tricky through conventional methods. It can be overcome with the implementation of machine learning. This article concisely delineates the application of machine learning algorithms for modeling printability as a function of influential parameters was elaborately discussed. Additionally, indispensable challenges and futuristic aspects were briefed concerning tissue regeneration applications.

Human limb surrogates, of varying biofidelity, are used in the performance assessment of sports personal protective equipment (PPE). Such biofidelic surrogates have incorporated soft tissue simulants (silicones) and synthetic bone (short fibre filled epoxy). Testing surrogates incorporating realistic synthetic bone could help to further our knowledge of fracture trauma mechanics, and applications such as the effectiveness of sports PPE. Limb surrogates with embedded synthetic bone are rarely tested to fracture, mainly due to the effort and cost of replacing them. This paper proposes additive manufacturing of synthetic bones, with appropriate bone like fracture characteristics, potentially making them more accessible and cost effective. A Markforged® X7™ printer was used as it prints a base filament (Onyx™) alongside a continuous strand of reinforcement (e.g., carbon fibre). The properties of specimens from this printer vary with the type, volume fraction and position of reinforcement. Bar specimens (10 × 4 × 120 mm) with varying amounts of carbon fibre reinforcement were printed for three-point bend testing to determine the feasibility of achieving mechanical properties close to compact bone (bending modulus of ∼15 GPa, bending strength of ∼180 MPa). Bending strength for the various bar specimens ranged from 32 to 378 MPa, and modulus values ranged from 1.5 to 25.8 GPa. Based on these results, four 140 mm long oval shaped cylindrical specimens of ø14 and ø16 mm were printed to represent a basic radius bone model. Three-point bend testing of these bone models showed similar bending modulus (3.8 to 5.3 GPa vs. 3.66 to 14.8 GPa) to radius bones reported in the literature, but higher bending strength (147 to 200 MPa vs. 80.31 ± 14.55 MPa).

Introduction

Nonrecognition of smaller bone anatomy in the context of the Latarjet procedure may increase the chance of complications and worsen it outcomes, and this should be addressed preoperatively by accurate measuring of bone anatomy. Measurement of bone dimension can be performed through 3d printed bone models nowadays and therefore we aimed to evaluate glenoid and coracoid process dimensions obtained in 3D printed bone models, assess differences between genders, and compare the results with previously published anatomical studies. We hypothesized that the values obtained in the 3D models would be similar to those previously reported in other anatomical studies and gender differences would also be present.

Methods

We retrospectively retrieved shoulder computer tomography scans from 39 adult patients with uninjured scapula. Using the DICOM file of the CT, we performed three-dimensional reconstructions of the scapula, including the glenoid and coracoid. The resulting digital model was then printed in an FDM technology 3D printer. With the 3D Printed models, one of the authors measured the models using a digital caliper. The measurements collected on the Glenoid were Glenoid Superior-Inferior length (GlenSI); and Glenoid Antero-Inferior length (GlenAP) .On the coracoid, the measurements collected were the Coracoid Anterior-Posterior length (CoracAP), the Coracoid Medial-Lateral (CoracML) distance and the Coracoid Superior-Inferior (CoracSI) distance. Those measurements were summarized and underwent statistical comparison between genders. The results were compared with other anatomical studies in the same bone anatomy.

Results

We recorded a mean glenoid length (GlenAP) of 28.03 mm (SD = 0.45) and mean glenoid height (GlenSI) of 37,18 mm (SD =0,55). The mean glenoid dimensions differ significantly between male and female gender (p=0,002 and p=0,001, respectively).The coracoid mean length was 22,35 mm (SD=0.47), mean coracoid width was 14,97 mm (SD=0,30), mean coracoid height was9,51 mm (SD=0,22), and those measures also differ significantly between genders. The observed mean values were similar to those previously reported in other anatomical studies.

Discussion

We observed that coracoid and glenoid dimensions significantly vary between genders for all of the measurements performed. Measurements obtained in this series are comparable with other similar anatomic studies. Although some limitations exists in our study, we consider 3D-printed bone models in the setting of anatomical studies as a relevant option to traditional cadaveric studies.

Conclusion

Gender differences in coracoid and glenoid dimensions were observed and must be considered for the Latarjet procedure. Our results suggest that 3d printed bone models may be used for such evaluation with a good degree of reproducibility of the measurements observed in already publish