16 research outputs found

    Computer-assisted pre-operative automatic segmentation and registration tool for malunited radius osteotomy: A proof-of-concept study

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    Corrective osteotomy is a standard treatment for distal radius fractures in malunited radius cases. In order to increase the efficiency of the osteotomy pre-operative plan, in this study, a proof-of-concept framework of automatic computer-assisted segmentation and registration tool was developed for the purpose of malunited radius osteotomy pre-operative planning. The program consisted of the functions of segmentation, virtual cutting, automatic alignment and registration. One computed tomography (CT) scanning dataset of a patient's bilateral forearm was employed as an illustration example in this study. Three templates of 3D models including the healthy radius, and the pre- and post-correction injured radius were output as STL geometries for pre-operative plan purposes

    PolliRS: A 3D Printed Pollicization Retractor System that improves access and autonomy during the surgical procedure.

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    We demonstrate the design, manufacture, and deployment of the first custom-made 3-dimensional (3D)-printed hand retractor for the pollicization procedure. Radiological images of the patient’s hand were taken preoperatively to measure anatomical dimensions and guide the design of the device in a patient-precise manner. The 3D-printed, sterilizable, device was autoclaved and successfully used on a patient that underwent a pollicization procedure in our unit. The radiolucency of the device and the fluency enabled by the ability to exchange between different positions demonstrated the potential of this device in increasing the overall autonomy afforded to the lead-surgeon during the operation and demonstrated the potential of rapid-prototyping techniques such as 3D printing for producing patient-precise tools on-the-fly that taken account the specific needs of the patient

    Doctor of Philosophy

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    dissertationAltered mechanics are believed to initiate osteoarthritis in hips with acetabular dysplasia. Periacetabular osteotomy (PAO) is the preferred surgical treatment; however, it is unknown if the procedure normalizes joint anatomy and mechanics. Changes in three-dimensional (3D) morphology and chondrolabral mechanics were quantified after PAO. Finite element (FE) models demonstrated that PAO improved the distribution of coverage, reduced stress, increased congruity, and prevented cartilage thinning. However, changes in mechanics were not consistent. In fact, one patient exhibited increased stress after surgery, which was believed to be a result of over-correction. Therefore, methods to integrate morphologic and biomechanical analysis with clinical care could standardize outcomes of PAO. FE simulations are time-intensive and require significant computing resources. Therefore, the second aim was to implement an efficient method to estimate mechanics. An enhanced discrete element analysis (DEA) model of the hip that accurately incorporated cartilage geometry and efficiently calculated stress was developed and analyzed. Although DEA model estimates predicted elevated magnitudes of contact stress, the distribution corresponded well with FE models. As a computationally efficient platform, DEA could assist in diagnosis and surgical planning. Imaging is a precursor to analyzing morphology and biomechanics. Ideally, an imaging protocol would visualize bone and soft-tissue at high resolution without ionizing radiation. Magnetic resonance imaging (MRI) with 3D dual-echo-steady-state (DESS) is a promising sequence to image the hip noninvasively, but its accuracy has not been quantified. Therefore, the final aim was to implement and validate the use of 3D DESS MRI in the hip. Using direct measurements of cartilage thickness as the standard, 3D DESS MRI imaged cartilage to ~0.5 mm of the physical measurements with 95% confidence, which is comparable to the most accurate hip imaging protocol presented to date. In summary, this dissertation provided unique insights into the morphologic and biomechanical features following PAO. In the future, DEA could be combined with 3D DESS MRI to efficiently analyze contact stress distributions. These methods could be incorporated into preoperative planning software, where the algorithm would predict the optimal relocation of the acetabulum to maximize femoral head coverage while minimizing contact stress, and thereby improve long-term outcomes of PAO

    Impresión 3D en Cirugía Ortopédica y Traumatología. Revisión sistemática de su aplicabilidad y estudio de los métodos de esterilización más adecuados para la utilización en quirófanos de las impresiones realizadas en el hospital.

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    Introduction In-Hospital 3D printing has been broadly developed since the end of the addictive manufacturing patents. However, although there are many printing technologies, the most frequent in our field are Fused Deposition Modelling (FDM) and Stereolithography (SLA), which usually use hollow infill patterns in order to save time and material. It is common to use these models and surgical guides in the operating room, however, there were no publications warranting an adequate sterilization of the in-house prints. Objectives To describe systematically all the current applications of in-hospital 3D printing up to date and to run an experimental study which demonstrates the sterilization of the inside of our anatomical models and surgical guides. Material and Methods A systematic review was made on PubMed to obtain all the published articles regarding this topic up to December 2021. Those publications in other language (not in English or Spanish) or describing industrial applications, cell therapies, pharma therapies or involving human specimens were rejected. A record card was made for each application to make further search easier. For the experimental study, a total of 24 cylinders were designed and printed with a 3D printer in Polylactic Acid (PLA) with an infill density of 12%. Manufacturing was paused when 60% of the print was reached and 20 of the cylinders were inoculated with 0.4 mL of a suspension of S epidermidis ATTCC 1228 in saline solution at turbidity 1 McFarland. Printing was resumed, being all the pieces completely sealed with the inoculum inside. Posteriorly, 4 groups were made according to the chosen sterilization method: Ethylene Oxide (EtO), Gas Plasma, Steam Heat or non-sterilized (positive control). Each group included 5 contaminated cylinders and 1 non-contaminated cylinder as a negative control. After sterilization, the inside of the cylinders was cultured during 7 days. Results We obtained a total of 1193 articles in the research, of which 298 articles met the inclusion criteria, finding a total of 143 applications which are summarized as record cards. In the sterility study, we observed bacterial growth of just a few Forming Colony Units (FCU) in 4 out of 5 positive controls and in 2 out of 5 contaminated cylinders sterilized with Gas Plasma. We could not assess any bacterial growth in any of the EtO or Steam Heat samples or in any of the negative controls. Pieces sterilized under Steam Heat resulted completely deformed. Conclusions There are multiple applications for in-house 3D printing in the field of orthopaedics. High temperatures reached during the procedure of additive manufacturing can decrease the bacterial load of the biomodels. However, there is a potential risk of contamination during the proce- dure. We recommend sterilization with EtO for in-hospital 3D-printed PLA hollow biomodels or guides. Otherwise, in case of using Gas Plasma, an infill of 100% should be applied.Introducción La impresión 3D hospitalaria ha cobrado un gran impulso desde la liberalización de las patentes sobre la fabricación aditiva. Aunque existen multitud de tecnologías de impresión, las más frecuentes en nuestro medio son la impresión por deposición de material fundido (FDM) y la impresión estereolitográfica (SLA), las cuales, suelen recurrir a patrones de relleno incompletos para ahorrar tiempo y material. Aunque es frecuente la utilización de biomodelos y guías quirúrgicas obtenidas por este medio en los quirófanos, no existían hasta la fecha estudios que garantizasen una adecuada esterilidad de los mismos. Objetivos Realizar una descripción sistematizada de todas las aplicaciones descritas de la impresión 3D hospitalaria hasta la fecha y hacer un estudio experimental que demuestre la capacidad esterilizante del interior de nuestros biomodelos y guías quirúrgicas. Material y Métodos Se realiza una revisión sistemática en PubMed para obtener todos los artículos publicados sobre el tema hasta diciembre de 2021, descartándose aquellos en otro idioma o que tratan sobre aplicaciones industriales, celulares, farmacológicas o experimentales en cadáver. Se realiza una ficha de cada una de las aplicaciones para facilitar su posterior consulta. Por otro lado, realizamos un estudio experimental con 24 cilindros impresos en ácido poliláctico con una densidad de relleno del 12%. La fabricación se detuvo cuando se alcanzó el 60% de la impresión y 20 de los cilindros se inocularon con 0.4mL de una suspensión de S epidermidis ATTCC 1228 en solución salina con una turbidez de 1 McFarland. Tras la inoculación, se continuó la impresión quedando las piezas completamente selladas con el inóculo en su interior. Posteriormente, se crearon 4 grupos de acuerdo con el método de esterilización empleado (Óxido de etileno, Gas plasma, Autoclave y grupo control positivo, sin esterilizar). Cada grupo incluyó 5 cilindros contaminados y 1 no contaminado como control negativo. Tras la esterilización, el interior de los cilindros se cultivó durante 7 días. Resultados Se han obtenido un total de 1193 artículos en la búsqueda de los cuales 298 artículos cumplieron los criterios de inclusión, obteniéndose un total de 143 aplicaciones que se exponen a modo de fichas. En el estudio de esterilidad se observe crecimiento bacteriano de unas pocas unidades formadoras de colonias en 4 de los 5 controles positivos y en 2 de los 5 cilindros contaminados y esterilizados con Gas plasma. No se observó crecimiento en ninguno de los cilindros esteriliados con Óxido de etileno o Autoclave, ni tampoco en ninguno de los controles negativos. Sin embargo, aquellas muestras esterilizadas en Autoclave se encontraron completamente deformadas. Conclusiones Existen infinidad de aplicaciones de la impresión 3D hospitalaria en el campo de la cirugía ortopédica y traumatología. Las altas temperaturas alcanzadas durante el proceso de fabricación aditiva pueden disminuir la carga bacteriana de los biomodelos. Sin embargo, existe un riesgo potencial de contaminación durante el procedimiento, por lo que recomendamos la esterilización con Óxido de etileno para las impresiones intrahospitalarias de biomodelos y guías huecas realizadas con ácido poliláctico. En caso de utilizar Gas plasma, recomendamos un relleno del 100% o la utilización de otros materiales más resistentes a las altas temperaturas del Autoclave.Escuela de DoctoradoDoctorado en Investigación en Ciencias de la Salu

    PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

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    The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery

    Medical Robotics

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    The first generation of surgical robots are already being installed in a number of operating rooms around the world. Robotics is being introduced to medicine because it allows for unprecedented control and precision of surgical instruments in minimally invasive procedures. So far, robots have been used to position an endoscope, perform gallbladder surgery and correct gastroesophogeal reflux and heartburn. The ultimate goal of the robotic surgery field is to design a robot that can be used to perform closed-chest, beating-heart surgery. The use of robotics in surgery will expand over the next decades without any doubt. Minimally Invasive Surgery (MIS) is a revolutionary approach in surgery. In MIS, the operation is performed with instruments and viewing equipment inserted into the body through small incisions created by the surgeon, in contrast to open surgery with large incisions. This minimizes surgical trauma and damage to healthy tissue, resulting in shorter patient recovery time. The aim of this book is to provide an overview of the state-of-art, to present new ideas, original results and practical experiences in this expanding area. Nevertheless, many chapters in the book concern advanced research on this growing area. The book provides critical analysis of clinical trials, assessment of the benefits and risks of the application of these technologies. This book is certainly a small sample of the research activity on Medical Robotics going on around the globe as you read it, but it surely covers a good deal of what has been done in the field recently, and as such it works as a valuable source for researchers interested in the involved subjects, whether they are currently “medical roboticists” or not

    Sistema di realtà virtuale per la simulazione chirurgica CAD-based

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    Una componente importante della pianificazione chirurgica è la progettazione di ausili chirurgici per la progettazione di impianti o in generale dispositivi medici personalizzati. Uno degli aspetti più cruciali di questa procedura è la comunicazione tra progettista e chirurgo. Le inefficienze derivanti da un confronto poco chiaro tra le due parti portano a risultati indesiderati e ad un sostanziale aumento del tempo necessario per completare la progettazione e la produzione, ma possono essere ridotti al minimo quando queste due figure sono la stessa persona. Dato che attualmente è improponibile pensare di escludere completamente il ruolo dell’esperto CAD da questo processo, si sono comunque perseguiti degli obiettivi come la standardizzazione della procedura di progettazione e il raggiungimento di un processo efficace; dal momento che la maggiore affidabilità di una prassi così standardizzata rappresenta uno dei fattori fondamentali al fine di ridurre anche i rischi per i pazienti. In letteratura è evidente come tra gli approcci presi in considerazione per tentare di ridurre queste divergenze c’è stata la realtà virtuale. Si tratta di una tecnologia di tendenza, ampiamente accessibile e contemporanea di crescente utilità per le applicazioni biomediche e sanitarie. Tuttavia, la maggior parte delle implementazioni degli ambienti di realtà virtuale sono personalizzate per applicazioni specifiche. Nel presente elaborato si descrive lo sviluppo completo di un nuovo ambiente di realtà virtuale, svolto attraverso la piattaforma Unity, il quale prevede l’importazione di modelli CAD di parti anatomiche che necessitano di intervento chirurgico ablativo di parte della struttura ossea. Ciò che l’applicazione consente di fare è visualizzare interattivamente i modelli CAD e di utilizzare strumenti che consentono la individuazione e selezione delle direzioni di taglio più ottimali rispetto alle quali sono successivamente progettate le dime chirurgiche, importando per ultimo queste informazioni sul software Geomagic Design X di 3D Systems. L’approccio proposto è stato utile per verificare che il sistema di realtà virtuale permette di risparmiare step rispetto alla procedura convenzionalmente eseguita su Geomagic Design X e che pertanto offrirebbe al clinico uno strumento semplice ed intuitivo che lo renderebbe autonomo nelle prime fasi di simulazione chirurgica.An important component of surgical planning is the design of surgical aids for the design of implants or in general customized medical devices. One of the most crucial aspects of this procedure is the communication between the designer and the surgeon. The inefficiencies resulting from an unclear comparison between the two parties lead to undesirable results and a substantial increase in the time required to complete the design and production, but can be minimized when these two figures are the same person. Given that it is currently unthinkable to think of completely excluding the role of the CAD expert from this process, objectives such as the standardization of the design procedure and the achievement of an effective process have nevertheless been pursued; since the greater reliability of such a standardized practice represents one of the fundamental factors in order to also reduce the risks for patients. In the literature it is clear that virtual reality was one of the approaches taken into consideration to try to reduce these differences. It is a trendy, widely accessible and contemporary technology of increasing utility for biomedical and healthcare applications. However, most implementations of virtual reality environments are customized for specific applications. This paper describes the complete development of a new virtual reality environment, carried out through the Unity platform, which provides for the import of CAD models of anatomical parts that require ablative surgery of part of the bone structure. What the application allows you to do is interactively view the CAD models and to use tools that allow the identification and selection of the most optimal cutting directions with respect to which the surgical guides are subsequently designed, importing this information into the Geomagic Design X software by 3D Systems. The proposed approach was useful for verifying that the virtual reality system saves steps compared to the procedure conventionally performed on Geomagic Design X and that it would therefore offer the clinician a simple and intuitive tool that would make him autonomous in the early stages of surgical simulation

    Implementation of a semiautomatic method to design patient-specific instruments for corrective osteotomy of the radius

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    PURPOSE: 3D-printed patient-specific instruments (PSIs), such as surgical guides and implants, show great promise for accurate navigation in surgical correction of post-traumatic deformities of the distal radius. However, existing costs of computer-aided design and manufacturing process prevent everyday surgical use. In this paper, we propose an innovative semiautomatic methodology to streamline the PSIs design. METHODS: The new method was implemented as an extension of our existing 3D planning software. It facilitates the design of a regular and smooth implant and a companion guide starting from a user-selected surface on the affected bone. We evaluated the software by designing PSIs starting from preoperative virtual 3D plans of five patients previously treated at our institute for corrective osteotomy. We repeated the design for the same cases also with commercially available software, with and without dedicated customization. We measured design time and tracked user activity during the design process of implants, guides and subsequent modifications. RESULTS: All the designed shapes were considered valid. Median design times ([Formula: see text]) were reduced for implants (([Formula: see text]) = 2.2 min) and guides (([Formula: see text]) = 1.0 min) compared to the standard (([Formula: see text]) = 13 min and ([Formula: see text]) = 8 min) and the partially customized (([Formula: see text]) = 6.5 min and ([Formula: see text]) = 6.0 min) commercially available alternatives. Mouse and keyboard activities were reduced (median count of strokes and clicks during implant design (([Formula: see text]) = 53, and guide design (([Formula: see text]) = 27) compared to using standard software (([Formula: see text]) = 559 and ([Formula: see text]) = 380) and customized commercial software (([Formula: see text]) = 217 and ([Formula: see text]) = 180). CONCLUSION: Our software solution efficiently streamlines the design of PSIs for distal radius malunion. It represents a first step in making 3D-printed PSIs technology more accessible
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