Patient-Specific Clavicle Reconstruction Using Digital Design and Additive Manufacturing

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Marie Cronskär ◽  
Lars-Erik Rännar ◽  
Mikael Bäckström ◽  
Kjell G Nilsson ◽  
Börje Samuelsson
Keyword(s):  
Additive Manufacturing ◽  
Complex Shape ◽  
Plate Osteosynthesis ◽  
Operating Time ◽  
Digital Design ◽  
Patient Specific ◽  
Functional Design ◽  
Actual Case ◽  
Clavicle Fractures ◽  
Ct Data

There is a trend toward operative treatment for certain types of clavicle fractures and these are usually treated with plate osteosynthesis. The subcutaneous location of the clavicle makes the plate fit important, but the clavicle has a complex shape, which varies greatly between individuals and hence standard plates often have a poor fit. Using computed tomography (CT) based design, the plate contour and screw positioning can be optimized to the actual case. A method for patient-specific plating using design based on CT-data, additive manufacturing (AM), and postprocessing was initially evaluated through three case studies, and the plate fit on the reduced fracture was tested during surgery (then replaced by commercial plates). In all three cases, the plates had an adequate fit on the reduced fracture. The time span from CT scan of the fracture to final implant was two days. An approach to achieve functional design and screw-hole positioning was initiated. These initial trials of patient-specific clavicle plating using AM indicate the potential for a smoother plate with optimized screw positioning. Further, the approach facilitates the surgeon's work and operating time can be saved.

scholarly journals A Comprehensive 3D-Molded Bone Flap Protocol for Patient-Specific Cranioplasty

2021 ◽  
Author(s):  
Raphael Bertani ◽  
Caio Moreno Perret Novo ◽  
Pedro Henrique Freitas ◽  
Amanda Amorin Nunes ◽  
Thiago Nunes Palhares ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Operating Time ◽  
Ct Scanning ◽  
Patient Specific ◽  
Manufacturing Cost ◽  
Post Processing ◽  
Cross Sectional ◽  
Cranial Defect

Abstract We present a detailed step-by-step approach for the low-cost production and surgical implantation of cranial prostheses, aimed at restoring aesthetics, cerebral protection, and facilitating neurological rehabilitation. This protocol uses combined scan computed tomography (CT) cross-sectional images, in DICOM format, along with a 3D printing (additive manufacturing) setup. The in-house developed software InVesalius®️ is an open-source tool for medical imaging manipulation. The protocol describes image acquisition (CT scanning) procedures, and image post-processing procedures such as image segmentation, surface/volume rendering, mesh generation of a 3D digital model of the cranial defect and the desired prostheses, and their preparation for use in 3D printers. Furthermore, the protocol describes a detailed powder bed fusion additive manufacturing process, known as Selective Laser Sintering (SLS), using Polyamide (PA12) as feedstock to produce a 3-piece customized printed set per patient. Each set consists of a “cranial defect printout” and a “testing prosthesis” to assemble parts for precision testing, and a cranial “prostheses mold” in 2 parts to allow for the intraoperative modeling of the final implant cast using the medical grade Poly(methyl methacrylate) (PMMA) in a time span of a few min. The entire 3D processing time, including modelling, design, production, post-processing and qualification, takes approximately 42 h. Modeling the PMMA flap with a critical thickness of 4 mm by means of Finite Element Method (FEM) assures mechanical and impact properties to be slightly weaker than the bone tissue around it, a safety design to prevent fracturing the skull after a possible subsequent episode of head injury. On a parallel track, the Protocol seeks to provide guidance in the context of equipment, manufacturing cost and troubleshooting. Customized 3D PMMA prostheses offers a reduced operating time, good biocompatibility, and great functional and aesthetic outcomes. Additionally, it offers greater than 15-fold cost advantage over the usage of other materials, including metallic parts produced by additive manufacturing.

scholarly journals Topology and FEA modeling and optimization of a patient-specific zygoma implant

2021 ◽  
Author(s):  
Abhijit Cholkar ◽  
David Kinahan ◽  
Dermot Brabazon
Keyword(s):  
Additive Manufacturing ◽  
Optimum Design ◽  
Optimization Technique ◽  
Operating Time ◽  
Topological Optimization ◽  
Implant Design ◽  
Patient Specific ◽  
Stainless Steel 316L ◽  
Element Analysis ◽  
Suitable Material

Additive manufacturing has proven to be a very beneficial production technology in the medical and healthcare industries. While existing for over four decades, recent work has seen great improvements in the quality of products; particularly in medical devices such as implants. Improved customization reduced operating time and increased cost-effectiveness associated with Metal AM for these products offers a new value proposition.  This paper investigates and evaluates modelling methods for the zygoma bone (human jawbone) and explores the most suitable material and optimum design for this critical biomedical implant. This paper proposes an innovative and efficient pre-process methodology that includes modelling, design validation, topological optimization, and numerical analysis. The method includes the generation of the model using reverse engineering of CT scan data and a topology optimization technique which makes the implant lightweight without causing excessive stress concentration. Static structural Finite Element Analysis was conducted to test three different biocompatible materials (Ti6Al4V, stainless steel 316L and CoCr alloys) which are commonly available for metal additive manufacturing. The stresses and conditions in the analysis were that of the human mastication process and all the implant design were tested with the three material types. The Taguchi method was used to determine the optimum design which was found to result in the highest mass reduction of 25% with Ti6Al4V as the implant material.

scholarly journals Application of 3D Printing Technology in Orthopedic Medical Implant -Spinal surgery as an example

2019 ◽  
Vol 5 (2) ◽  
pp. 3
Author(s):  
Rong Feng Zhang ◽  
Peng Yun Wang ◽  
Ming Yang ◽  
Xuebo Dong ◽  
Xue Liu ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Spinal Surgery ◽  
Surgical Planning ◽  
Operating Time ◽  
Manufacturing Technology ◽  
Patient Specific ◽  
Additive Manufacturing Technology ◽  
Patient Specific Implants ◽  
Surgical Guides ◽  
Communication Aid

Additive manufacturing has been used in complex spinal surgical planning since the 1990s and is now increasingly utilized to produce surgical guides, templates, and more recently customized implants. Surgeons report beneficial impacts using additively manufactured biomodels as pre-operative planning aids as it generally provides a better representation of the patient’s anatomy than on-screen viewing of computed tomography (CT) or magnetic resonance imaging (MRI). Furthermore, it has proven to be very beneficial in surgical training and in explaining complex deformity and surgical plans to patients/ parents. This paper reviews the historical perspective, current use, and future directions in using additive manufacturing in complex spinal surgery cases. This review reflects the authors’ opinion of where the field is moving in light of the current literature. Despite the reported benefits of additive manufacturing for surgical planning in recent years, it remains a high niche market. This review raises the question as to why the use of this technology has not progressed more rapidly despite the reported advantages – decreased operating time, decreased radiation exposure to patients intraoperatively, improved overall surgical outcomes, pre-operative implant selection, as well as being an excellent communication aid for all medical and surgical team members. Increasingly, the greatest benefits of additive manufacturing technology in spinal surgery are customdesigned drill guides, templates for pedicle screw placement, and customized patient-specific implants. In view of these applications, additive manufacturing technology could potentially revolutionize health care in the near future.

scholarly journals Patient-specific hip prostheses designed by surgeons

2016 ◽  
Vol 2 (1) ◽  
pp. 565-567
Author(s):  
Florian Coigny ◽  
Adi Todor ◽  
Horatiu Rotaru ◽  
Ralf Schumacher ◽  
Erik Schkommodau
Keyword(s):  
Additive Manufacturing ◽  
Patient Specific ◽  
Shape Information ◽  
Hip Prostheses ◽  
Patient Specific Implants ◽  
Aesthetic Results ◽  
Design Software ◽  
Low Volume ◽  
Ct Data ◽  
User Friendly

AbstractPatient-specific bone and joint replacement implants lead to better functional and aesthetic results than conventional methods [1], [2], [3]. But extracting 3D shape information from CT Data and designing individual implants is demanding and requires multiple surgeon-to-engineer interactions. For manufacturing purposes, Additive Manufacturing offers various advantages, especially for low volume manufacturing parts, such as patient specific implants. To ease these new approaches and to avoid surgeon-to-engineer interactions a new design software approach is needed which offers highly automated and user friendly planning steps.

scholarly journals Selective Laser Melting of Patient Individualized Osteosynthesis Plates—Digital to Physical Process Chain

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5786
Author(s):  
André Edelmann ◽  
Monique Dubis ◽  
Ralf Hellmann
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Physical Process ◽  
Computer Tomography ◽  
Selective Laser Sintering ◽  
Patient Specific ◽  
Process Chain ◽  
Laser Melting ◽  
Osteosynthesis Plate ◽  
Ct Data

We report on the exemplified realization of a digital to physical process chain for a patient individualized osteosynthesis plate for the tarsal bone area. Anonymized patient-specific data of the right feet were captured by computer tomography, which were then digitally processed to generate a surface file format (standard tessellation language, STL) ready for additive manufacturing. Physical realization by selective laser melting in titanium using optimized parameter settings and post-processing by stress relief annealing results in a customized osteosynthesis plate with superior properties fulfilling medical demands. High fitting accuracy was demonstrated by applying the osteosynthesis plate to an equally good 3D printed bone model, which likewise was generated using the patient-specific computer tomography (CT) data employing selective laser sintering and polyamid 12. Proper fixation has been achieved without any further manipulation of the plate using standard screws, proving that based on CT data, individualized implants well adapted to the anatomical conditions can be accomplished without the need for additional steps, such as bending, cutting and shape trimming of precast bone plates during the surgical intervention. Beyond parameter optimization for selective laser melting, this exemplified digital to physical process chain highlights the potential of additive manufacturing for individualized osteosynthesis.

Effect of CT-based attenuation correction on uptake ratios in skeletal SPECT

2007 ◽  
Vol 46 (01) ◽  
pp. 38-42 ◽  
Author(s):  
V. Schulz ◽  
I. Nickel ◽  
A. Nömayr ◽  
A. H. Vija ◽  
C. Hocke ◽  
...  
Keyword(s):  
Vertebral Body ◽  
Facet Joint ◽  
One Dimension ◽  
Patient Specific ◽  
Data Sets ◽  
Facet Joints ◽  
Lumbar Vertebral Body ◽  
Ct System ◽  
Ct Data ◽  
Attenuation Corrected

SummaryThe aim of this study was to determine the clinical relevance of compensating SPECT data for patient specific attenuation by the use of CT data simultaneously acquired with SPECT/CT when analyzing the skeletal uptake of polyphosphonates (DPD). Furthermore, the influence of misregistration between SPECT and CT data on uptake ratios was investigated. Methods: Thirty-six data sets from bone SPECTs performed on a hybrid SPECT/CT system were retrospectively analyzed. Using regions of interest (ROIs), raw counts were determined in the fifth lumbar vertebral body, its facet joints, both anterior iliacal spinae, and of the whole transversal slice. ROI measurements were performed in uncorrected (NAC) and attenuation-corrected (AC) images. Furthermore, the ROI measurements were also performed in AC scans in which SPECT and CT images had been misaligned by 1 cm in one dimension beforehand (ACX, ACY, ACZ). Results: After AC, DPD uptake ratios differed significantly from the NAC values in all regions studied ranging from 32% for the left facet joint to 39% for the vertebral body. AC using misaligned pairs of patient data sets led to a significant change of whole-slice uptake ratios whose differences ranged from 3,5 to 25%. For ACX, the average left-to-right ratio of the facet joints was by 8% and for the superior iliacal spines by 31% lower than the values determined for the matched images (p <0.05). Conclusions: AC significantly affects DPD uptake ratios. Furthermore, misalignment between SPECT and CT may introduce significant errors in quantification, potentially also affecting leftto- right ratios. Therefore, at clinical evaluation of attenuation- corrected scans special attention should be given to possible misalignments between SPECT and CT.

scholarly journals Size Effects in Finite Element Modelling of 3D Printed Bone Scaffolds Using Hydroxyapatite PEOT/PBT Composites

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1746
Author(s):  
Iñigo Calderon-Uriszar-Aldaca ◽  
Sergio Perez ◽  
Ravi Sinha ◽  
Maria Camara-Torres ◽  
Sara Villanueva ◽  
...  
Keyword(s):  
Finite Element ◽  
Additive Manufacturing ◽  
Tissue Regeneration ◽  
Finite Element Modelling ◽  
Bulk Material ◽  
Bone Tissue Regeneration ◽  
Patient Specific ◽  
Design Factor ◽  
Element Modelling ◽  
Uncertainty Sources

Additive manufacturing (AM) of scaffolds enables the fabrication of customized patient-specific implants for tissue regeneration. Scaffold customization does not involve only the macroscale shape of the final implant, but also their microscopic pore geometry and material properties, which are dependent on optimizable topology. A good match between the experimental data of AM scaffolds and the models is obtained when there is just a few millimetres at least in one direction. Here, we describe a methodology to perform finite element modelling on AM scaffolds for bone tissue regeneration with clinically relevant dimensions (i.e., volume > 1 cm3). The simulation used an equivalent cubic eight node finite elements mesh, and the materials properties were derived both empirically and numerically, from bulk material direct testing and simulated tests on scaffolds. The experimental validation was performed using poly(ethylene oxide terephthalate)-poly(butylene terephthalate) (PEOT/PBT) copolymers and 45 wt% nano hydroxyapatite fillers composites. By applying this methodology on three separate scaffold architectures with volumes larger than 1 cm3, the simulations overestimated the scaffold performance, resulting in 150–290% stiffer than average values obtained in the validation tests. The results mismatch highlighted the relevance of the lack of printing accuracy that is characteristic of the additive manufacturing process. Accordingly, a sensitivity analysis was performed on nine detected uncertainty sources, studying their influence. After the definition of acceptable execution tolerances and reliability levels, a design factor was defined to calibrate the methodology under expectable and conservative scenarios.

scholarly journals 3D Plotting of Silica/Collagen Xerogel Granules in an Alginate Matrix for Tissue-Engineered Bone Implants

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 830
Author(s):  
Sina Rößler ◽  
Andreas Brückner ◽  
Iris Kruppke ◽  
Hans-Peter Wiesmann ◽  
Thomas Hanke ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Bone Regeneration ◽  
Material Properties ◽  
Viscoelastic Properties ◽  
Viscoelastic Behavior ◽  
Matrix Phase ◽  
Patient Specific ◽  
Active Player ◽  
Alginate Concentration ◽  
Alginate Matrix

Today, materials designed for bone regeneration are requested to be degradable and resorbable, bioactive, porous, and osteoconductive, as well as to be an active player in the bone-remodeling process. Multiphasic silica/collagen Xerogels were shown, earlier, to meet these requirements. The aim of the present study was to use these excellent material properties of silica/collagen Xerogels and to process them by additive manufacturing, in this case 3D plotting, to generate implants matching patient specific shapes of fractures or lesions. The concept is to have Xerogel granules as active major components embedded, to a large proportion, in a matrix that binds the granules in the scaffold. By using viscoelastic alginate as matrix, pastes of Xerogel granules were processed via 3D plotting. Moreover, alginate concentration was shown to be the key to a high content of irregularly shaped Xerogel granules embedded in a minimum of matrix phase. Both the alginate matrix and Xerogel granules were also shown to influence viscoelastic behavior of the paste, as well as the dimensionally stability of the scaffolds. In conclusion, 3D plotting of Xerogel granules was successfully established by using viscoelastic properties of alginate as matrix phase.

Accuracy of Patient-Specific 3D Printed Drill Guides in the Placement of a Canine Coxofemoral Toggle Pin through a Minimally Invasive Approach

2020 ◽  
Author(s):  
Brett G. Darrow ◽  
Kyle A. Snowdon ◽  
Adrien Hespel
Keyword(s):  
Minimally Invasive ◽  
Three Dimensional ◽  
Bone Tunnel ◽  
Patient Specific ◽  
Exit Point ◽  
Minimally Invasive Approach ◽  
Invasive Approach ◽  
Post Procedure ◽  
Drill Guide ◽  
Ct Data

Abstract Objective The aim of this study was to evaluate the accuracy of patient-specific three-dimensional printed drill guides (3D-PDG) for the placement of a coxofemoral toggle via a minimally invasive approach. Materials and Methods Pre-procedure computed tomography (CT) data of 19 canine cadaveric hips were used to design a cadaver-specific 3D-PDG that conformed to the proximal femur. Femoral and acetabular bone tunnels were drilled through the 3D-PDG, and a coxofemoral toggle pin was placed. The accuracy of tunnel placement was evaluated with post-procedure CT and gross dissection. Results Coxofemoral toggle pins were successfully placed in all dogs. Mean exit point translation at the fovea capitis was 2.5 mm (0.2–7.5) when comparing pre- and post-procedure CT scans. Gross dissection revealed the bone tunnel exited the fovea capitis inside (3/19), partially inside (12/19) and outside of (4/19) the ligament of the head of the femur. Placement of the bone tunnel through the acetabulum was inside (16/19), partially inside (1/19) and outside (2/19) of the acetabular fossa. Small 1 to 2 mm articular cartilage fragments were noted in 10 of 19 specimens. Clinical Significance Three-dimensional printed drill guide designed for coxofemoral toggle pin application is feasible. Errors are attributed to surgical execution and identification of the borders of the fovea capitis on CT data. Future studies should investigate modifications to 3D-PDG design and methods. Three-dimensional printed drill guide for coxofemoral toggle pin placement warrants consideration for use in select clinical cases of traumatic coxofemoral luxation.

Sign in / Sign up

Export Citation Format

Share Document