The “springform” technique in cranioplasty: custom made 3D-printed templates for intraoperative modelling of polymethylmethacrylate cranial implants

Abstract Background Manual moulding of cranioplasty implants after craniectomy is feasible, but does not always yield satisfying cosmetic results. In contrast, 3D printing can provide precise templates for intraoperative moulding of polymethylmethacrylate (PMMA) implants in cranioplasty. Here, we present a novel and easily implementable 3D printing workflow to produce patient-specific, sterilisable templates for PMMA implant moulding in cranioplastic neurosurgery. Methods 3D printable templates of patients with large skull defects before and after craniectomy were designed virtually from cranial CT scans. Both templates — a mould to reconstruct the outer skull shape and a ring representing the craniectomy defect margins — were printed on a desktop 3D printer with biocompatible photopolymer resins and sterilised after curing. Implant moulding and implantation were then performed intraoperatively using the templates. Clinical and radiological data were retrospectively analysed. Results Sixteen PMMA implants were performed on 14 consecutive patients within a time span of 10 months. The median defect size was 83.4 cm2 (range 57.8–120.1 cm2). Median age was 51 (range 21–80) years, and median operating time was 82.5 (range 52–152) min. No intraoperative complications occurred; PMMA moulding was uneventful and all implants fitted well into craniectomy defects. Excellent skull reconstruction could be confirmed in all postoperative computed tomography (CT) scans. In three (21.4%) patients with distinct risk factors for postoperative haematoma, revision surgery for epidural haematoma had to be performed. No surgery-related mortality or new and permanent neurologic deficits were recorded. Conclusion Our novel 3D printing-aided moulding workflow for elective cranioplasty with patient-specific PMMA implants proved to be an easily implementable alternative to solely manual implant moulding. The “springform” principle, focusing on reconstruction of the precraniectomy skull shape and perfect closure of the craniectomy defect, was feasible and showed excellent cosmetic results. The proposed method combines the precision and cosmetic advantages of computer-aided design (CAD) implants with the cost-effectiveness of manually moulded PMMA implants.

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3D Printing & Pharmaceutical Manufacturing: Opportunities and Challenges

International Journal of Bioassays ◽

10.21746/ijbio.2016.01.006 ◽

2016 ◽

Vol 5 (01) ◽

pp. 4723 ◽

Cited By ~ 5

Author(s):

Bhusnure O. G.* ◽

Gholve V. S. ◽

Sugave B. K. ◽

Dongre R. C. ◽

Gore S. A. ◽

...

Keyword(s):

Drug Delivery ◽

Tissue Engineering ◽

3D Printing ◽

Computer Aided Design ◽

Patient Specific ◽

Computer Design ◽

3D Scaffolds ◽

Engineering Research ◽

Advantages And Disadvantages ◽

Computer Aided

Many researchers have attempted to use computer-aided design (C.A.D) and computer-aided manufacturing (CAM) to realize a scaffold that provides a three-dimensional (3D) environment for regeneration of tissues and organs. As a result, several 3D printing technologies, including stereolithography, deposition modeling, inkjet-based printing and selective laser sintering have been developed. Because these 3D printing technologies use computers for design and fabrication, and they can fabricate 3D scaffolds as designed; as a consequence, they can be standardized. Growth of target tissues and organs requires the presence of appropriate growth factors, so fabrication of 3Dscaffold systems that release these biomolecules has been explored. A drug delivery system (D.D.S) that administrates a pharmaceutical compound to achieve a therapeutic effect in cells, animals and humans is a key technology that delivers biomolecules without side effects caused by excessive doses. 3D printing technologies and D. D. Ss have been assembled successfully, so new possibilities for improved tissue regeneration have been suggested. If the interaction between cells and scaffold system with biomolecules can be understood and controlled, and if an optimal 3D tissue regenerating environment is realized, 3D printing technologies will become an important aspect of tissue engineering research in the near future. 3D Printing promises to produce complex biomedical devices according to computer design using patient-specific anatomical data. Since its initial use as pre-surgical visualization models and tooling molds, 3D Printing has slowly evolved to create one-of-a-kind devices, implants, scaffolds for tissue engineering, diagnostic platforms, and drug delivery systems. Fuelled by the recent explosion in public interest and access to affordable printers, there is renewed interest to combine stem cells with custom 3D scaffolds for personalized regenerative medicine. Before 3D Printing can be used routinely for the regeneration of complex tissues (e.g. bone, cartilage, muscles, vessels, nerves in the craniomaxillofacial complex), and complex organs with intricate 3D microarchitecture (e.g. liver, lymphoid organs), several technological limitations must be addressed. Until recently, tablet designs had been restricted to the relatively small number of shapes that are easily achievable using traditional manufacturing methods. As 3D printing capabilities develop further, safety and regulatory concerns are addressed and the cost of the technology falls, contract manufacturers and pharmaceutical companies that experiment with these 3D printing innovations are likely to gain a competitive edge. This review compose the basics, types & techniques used, advantages and disadvantages of 3D printing

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An Innovative and Cost-Advantage CAD Solution for Cubitus Varus Surgical Planning in Children

Applied Sciences ◽

10.3390/app11094057 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4057

Author(s):

Leonardo Frizziero ◽

Gian Maria Santi ◽

Christian Leon-Cardenas ◽

Giampiero Donnici ◽

Alfredo Liverani ◽

...

Keyword(s):

Computer Aided Design ◽

Low Cost ◽

Cost Effective ◽

Varus Deformity ◽

Patient Specific ◽

Cubitus Varus ◽

Surgical Guide ◽

Traditional Procedure ◽

Custom Made ◽

Patient Specific Instruments

The study of CAD (computer aided design) modeling, design and manufacturing techniques has undergone a rapid growth over the past decades. In medicine, this development mainly concerned the dental and maxillofacial sectors. Significant progress has also been made in orthopedics with pre-operative CAD simulations, printing of bone models and production of patient-specific instruments. However, the traditional procedure that formulates the surgical plan based exclusively on two-dimensional images and interventions performed without the aid of specific instruments for the patient and is currently the most used surgical technique. The production of custom-made tools for the patient, in fact, is often expensive and its use is limited to a few hospitals. The purpose of this study is to show an innovative and cost-effective procedure aimed at prototyping a custom-made surgical guide for address the cubitus varus deformity on a pediatric patient. The cutting guides were obtained through an additive manufacturing process that starts from the 3D digital model of the patient’s bone and allows to design specific models using Creo Parametric. The result is a tool that adheres perfectly to the patient’s bone and guides the surgeon during the osteotomy procedure. The low cost of the methodology described makes it worth noticing by any health institution.

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Innovative Design Methodology for Patient-Specific Short Femoral Stems

Materials ◽

10.3390/ma15020442 ◽

2022 ◽

Vol 15 (2) ◽

pp. 442

Author(s):

William Solórzano-Requejo ◽

Carlos Ojeda ◽

Andrés Díaz Lantada

Keyword(s):

Computer Aided Design ◽

Design Methodology ◽

Patient Specific ◽

Bone Stock ◽

Innovative Design ◽

Hip Prostheses ◽

Custom Made ◽

In Silico Studies ◽

Femoral Stems ◽

Short Stems

The biomechanical performance of hip prostheses is often suboptimal, which leads to problems such as strain shielding, bone resorption and implant loosening, affecting the long-term viability of these implants for articular repair. Different studies have highlighted the interest of short stems for preserving bone stock and minimizing shielding, hence providing an alternative to conventional hip prostheses with long stems. Such short stems are especially valuable for younger patients, as they may require additional surgical interventions and replacements in the future, for which the preservation of bone stock is fundamental. Arguably, enhanced results may be achieved by combining the benefits of short stems with the possibilities of personalization, which are now empowered by a wise combination of medical images, computer-aided design and engineering resources and automated manufacturing tools. In this study, an innovative design methodology for custom-made short femoral stems is presented. The design process is enhanced through a novel app employing elliptical adjustment for the quasi-automated CAD modeling of personalized short femoral stems. The proposed methodology is validated by completely developing two personalized short femoral stems, which are evaluated by combining in silico studies (finite element method (FEM) simulations), for quantifying their biomechanical performance, and rapid prototyping, for evaluating implantability.

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Patient-Specific Coronary Artery 3D Printing Based on Intravascular Optical Coherence Tomography and Coronary Angiography

Complexity ◽

10.1155/2019/5712594 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Chenxi Huang ◽

Yisha Lan ◽

Sirui Chen ◽

Qing Liu ◽

Xin Luo ◽

...

Keyword(s):

Coronary Artery ◽

3D Printing ◽

Coronary Angiography ◽

Coronary Arteries ◽

Computer Aided Design ◽

Patient Specific ◽

3D Printing Technology ◽

Vessel Lumen ◽

Computer Aided ◽

Aided Design

Despite the new ideas were inspired in medical treatment by the rapid advancement of three-dimensional (3D) printing technology, there is still rare research work reported on 3D printing of coronary arteries being documented in the literature. In this work, the application value of 3D printing technology in the treatment of cardiovascular diseases has been explored via comparison study between the 3D printed vascular solid model and the computer aided design (CAD) model. In this paper, a new framework is proposed to achieve a 3D printing vascular model with high simulation. The patient-specific 3D reconstruction of the coronary arteries is performed by the detailed morphological information abstracted from the contour of the vessel lumen. In the process of reconstruction which has 5 steps, the morphological details of the contour view of the vessel lumen are merged along with the curvature and length information provided by the coronary angiography. After comparing with the diameter of the narrow section and the diameter of the normal section in CAD models and 3D printing model, it can be concluded that there is a high correlation between the diameter of vascular stenosis measured in 3D printing models and computer aided design models. The 3D printing model has high-modeling ability and high precision, which can represent the original coronary artery appearance accurately. It can be adapted for prevascularization planning to support doctors in determining the surgical procedures.

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Single-Step Resection of Sphenoorbital Meningiomas and Orbital Reconstruction Using Customized CAD/CAM Implants

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0039-1681044 ◽

2019 ◽

Vol 81 (02) ◽

pp. 142-148

Author(s):

Lukas Goertz ◽

Pantelis Stavrinou ◽

George Stranjalis ◽

Marco Timmer ◽

Roland Goldbrunner ◽

...

Keyword(s):

Computer Aided Design ◽

Tumor Resection ◽

Single Step ◽

Ct Scans ◽

Patient Specific ◽

Orbital Decompression ◽

Bone Resection ◽

Orbital Reconstruction ◽

Orbital Wall ◽

Cad Cam

Abstract Objective Computer-aided design and manufacturing (CAD/CAM) implants are fabricated based on volumetric analysis of computed tomography (CT) scans and are routinely used for the reconstruction of orbital fractures. We present three cases of patients with sphenoorbital meningiomas that underwent tumor resection, orbital decompression, and orbital reconstruction with patient specific porous titanium or acrylic implants in a single procedure. Methods The extent of bone resection of the sphenoorbital meningiomas was planned in a virtual three-dimensional (3D) environment using preoperative thin-layer CT data. The anatomy of the orbital wall in the resection area was reconstructed by superimposing the contralateral unaffected orbit and by using the information of the neighboring bony structures. The customized implants and a corresponding craniotomy template were designed in the desired size and shape by the manufacturer. Results All patients presented with a sphenoorbital meningioma and exophthalmos. After osteoclastic craniotomy with the drilling template, orbital decompression was performed. Implant fitting was tight in two cases and could be easily fixated with miniplates and screws. In the third patient, a reoperation was necessary for additional bone resection, as well as drilling and repositioning of the implant. The postoperative CT scans showed an accurate reconstruction of the orbital wall. After surgery, exophthalmos was substantially reduced and a satisfying cosmetic result could be finally achieved in all patients. Conclusions The concept of preoperative 3D virtual treatment planning and single-step orbital reconstruction with CAD/CAM implants after tumor resection involving the orbit is well feasible and can lead to good cosmetic results.

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Low cost digital fabrication approach for thumb orthoses

Rapid Prototyping Journal ◽

10.1108/rpj-12-2015-0187 ◽

2017 ◽

Vol 23 (6) ◽

pp. 1020-1031 ◽

Cited By ~ 4

Author(s):

Miguel Fernandez-Vicente ◽

Ana Escario Chust ◽

Andres Conejero

Keyword(s):

3D Printing ◽

Computer Aided Design ◽

Low Cost ◽

Three Dimensional ◽

Recovery Process ◽

Digital Fabrication ◽

Cost Comparison ◽

Content Type ◽

Custom Made ◽

The Impact

Purpose The purpose of this paper is to describe a novel design workflow for the digital fabrication of custom-made orthoses (CMIO). It is intended to provide an easier process for clinical practitioners and orthotic technicians alike. It further functions to reduce the dependency of the operators’ abilities and skills. Design/methodology/approach The technical assessment covers low-cost three-dimensional (3D) scanning, free computer-aided design (CAD) software, and desktop 3D printing and acetone vapour finishing. To analyse its viability, a cost comparison was carried out between the proposed workflow and the traditional CMIO manufacture method. Findings The results show that the proposed workflow is a technically feasible and cost-effective solution to improve upon the traditional process of design and manufacture of custom-made static trapeziometacarpal (TMC) orthoses. Further studies are needed for ensuring a clinically feasible approach and for estimating the efficacy of the method for the recovery process in patients. Social implications The feasibility of the process increases the impact of the study, as the great accessibility to this type of 3D printers makes the digital fabrication method easier to be adopted by operators. Originality/value Although some research has been conducted on digital fabrication of CMIO, few studies have investigated the use of desktop 3D printing in any systematic way. This study provides a first step in the exploration of a new design workflow using low-cost digital fabrication tools combined with non-manual finishing.

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3D Bioprinted Cardiac Tissues and Devices for Tissue Maturation

Cells Tissues Organs ◽

10.1159/000512792 ◽

2021 ◽

pp. 1-14

Author(s):

Veronika Sedlakova ◽

Christopher McTiernan ◽

David Cortes ◽

Erik J. Suuronen ◽

Emilio I. Alarcon

Keyword(s):

3D Printing ◽

Tissue Repair ◽

Surgical Planning ◽

Cardiac Tissue ◽

Treatment Options ◽

Cardiac Regeneration ◽

Patient Specific ◽

Cardiac Tissues ◽

Cardiovascular Tissue ◽

Custom Made

Cardiovascular diseases are the leading cause of mortality worldwide. Given the limited endogenous regenerative capabilities of cardiac tissue, patient-specific anatomy, challenges in treatment options, and shortage of donor tissues for transplantation, there is an urgent need for novel approaches in cardiac tissue repair. 3D bioprinting is a technology based on additive manufacturing which allows for the design of precisely controlled and spatially organized structures, which could possibly lead to solutions in cardiac tissue repair. In this review, we describe the basic morphological and physiological specifics of the heart and cardiac tissues and introduce the readers to the fundamental principles underlying 3D printing technology and some of the materials/approaches which have been used to date for cardiac repair. By summarizing recent progress in 3D printing of cardiac tissue and valves with respect to the key features of cardiovascular tissue (such as contractility, conductivity, and vascularization), we highlight how 3D printing can facilitate surgical planning and provide custom-fit implants and properties that match those from the native heart. Finally, we also discuss the suitability of this technology in the design and fabrication of custom-made devices intended for the maturation of the cardiac tissue, a process that has been shown to increase the viability of implants. Altogether this review shows that 3D printing and bioprinting are versatile and highly modulative technologies with wide applications in cardiac regeneration and beyond.

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Modern Applications of 3D Printing: The Case of an Artificial Ear Splint Model

Methods and Protocols ◽

10.3390/mps4030054 ◽

2021 ◽

Vol 4 (3) ◽

pp. 54

Author(s):

Athanasios Argyropoulos ◽

Pantelis N. Botsaris

Keyword(s):

3D Printing ◽

Three Dimensional ◽

Shape Preservation ◽

Patient Specific ◽

Fused Deposition Modelling ◽

Comprehensive Overview ◽

Protruding Ears ◽

Fused Deposition ◽

Custom Made ◽

Wide Range

Three-dimensional (3D) printing is a leading manufacturing technique in the medical field. The constantly improving quality of 3D printers has revolutionized the approach to new challenges in medicine for a wide range of applications including otoplasty, medical devices, and tissue engineering. The aim of this study is to provide a comprehensive overview of an artificial ear splint model applied to the human auricle for the treatment of stick-out protruding ears. The deformity of stick-out protruding ears remains a significant challenge, where the complex and distinctive shape preservation are key factors. To address this challenge, we have developed a protocol that involves photogrammetry techniques, reverse engineering technologies, a smart prototype design, and 3D printing processes. Specifically, we fabricated a 3D printed ear splint model via fused deposition modelling (FDM) technology by testing two materials, a thermoplastic polyester elastomer material (Z-Flex) and polycaprolactone (PCL 100). Our strategy affords a custom-made and patient-specific artificial ear aligner with mechanical properties that ensures sufficient preservation of the auricular shape by applying a force on the helix and antihelix and enables the ears to pin back to the head.

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A Comparison of the Accuracy of WATCHMAN and WATCHMAN FLX Device Sizing between CT, TEE, and Patient Specific 3D Models

Proceedings of IMPRS ◽

10.18060/25779 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Ivette Troitino ◽

T. Eric White ◽

John Lozo

Keyword(s):

3D Model ◽

Intraoperative Complications ◽

Statistical Significance ◽

3D Models ◽

Ct Scans ◽

Orifice Diameter ◽

Patient Specific ◽

Accuracy Of Measurements ◽

Device Size ◽

Actual Size

Background and Hypothesis: In patients with Atrial fibrillation (AF), the Left Atrial Appendage (LAA) is the most common site of thrombus formation. The LAA occlusion procedure using the WATCHMAN device implant is an alternative for stroke prevention in AF patients. Transesophageal echocardiogram (TEE) and Computed tomography (CT) scans aid in measuring the LAA to predict implant device sizes. However, due to varying LAA anatomy and limited spatial resolution, the current imaging techniques often predict one of two sized devices. The objective of this retrospective study is to compare the accuracy of measurements made preoperatively of the LAA with those on 3D models to determine if they can be used in preoperative planning. We hypothesize 3D models will be more accurate in predicting device size and any anatomical impediments than traditional TEE planning. Project Methods: There were 21 subjects selected who underwent the WATCHMAN FLX procedure at Parkview Heart Institute in 2021. 3D models of LAA were created from CT scans using a Form 2 3D printer. The device sizes predicted for the procedure were determined from Boston Scientific FLX guidelines based on the maximum LAA orifice diameter from TEE, CT, and 3D models. Results: Two-proportion z-test between the 3D model predicted sizes to the actual size deployed demonstrated no statistical significance (p=0.298) demonstrating no difference between 3D model predicted sizes and actual size deployed. Two-proportion z-test between TEE vs actual size and CT vs actual size demonstrated statistical significance, suggesting a difference between the group's predictions. 3D models predicted the accurate device size for 20/21(95%) subjects. TEE measurements of maximum orifice diameter were, on average, lower compared to CT and 3D model measurements. Conclusion and Potential Impact: 3D printed models provide the most accurate device size predictions and can be used to optimize presurgical planning while reducing intraoperative complications.

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Introduction of 3D Printing in a German Municipal Hospital—Practice Guide for CMF Surgery

Craniomaxillofacial Trauma & Reconstruction ◽

10.1177/19433875211050721 ◽

2021 ◽

pp. 194338752110507

Author(s):

H Gleissner ◽

G Castrillon-Oberndorfer ◽

St Gehrlich

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Operating Time ◽

Mandibular Reconstruction ◽

Patient Treatment ◽

Patient Specific ◽

Municipal Hospital ◽

Orbital Trauma ◽

Practice Guide ◽

Fused Deposition

Study Design: This study aimed to introduce 3D printing in a municipal hospital to improve the treatment of craniomaxillofacial patients and optimize costs and operating time. Thus we describe the implementation of low-cost in-house 3D printing to facilitate orbital- and mandible reconstruction in CMF surgery. Moreover, we address legal requirements, safety at work, fire- and data protection. Finally, we want to share our experiences using 3D printing and point out its advantages in providing better patient care. Methods: We outline the setup of in-house 3D printing and focus on obeying German health care regulations. We based our approach on a fused deposition modeling 3D printer and free software. As proof of concept, we treated 4 cases of severe orbital trauma and 1 case of mandibular reconstruction. We printed a 3D patient-specific model for each case and adapted a titanium mesh implant, respectively, a titanium reconstruction plate before performing the surgery. Results: Our approach reduced costs, duration of anesthesia, operating time, recovery time, and postoperative swelling and increased the revenue. Functional outcome in orbital reconstruction like eye movement and double vision, was improved compared to the conventional technique. No severe complications like loss-of-vision or surgical revision occurred. Likewise, mandibular reconstruction showed no plate loosening or plate fracture. Conclusion: The implementation of cost-efficient 3D printing resulted in successful patient treatment with excellent outcomes. Our practice guide offers a 3D printing workflow and could be adapted to fit the needs of other specialties like neurosurgery, orthopedic surgery as well.

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