In the last years, 3d printing has progressively grown and it has reached a solid role in clinical practice. The main applications brought by 3d printing in orthopedic surgery are: preoperative planning, custom-made surgical guides, custom-made im- plants, surgical simulation, and bioprinting. The replica of the patient's anatomy, starting from the elaboration of medical volumetric images (CT, MRI, etc.), allows a progressive extremization of treatment personalization that could be tailored for every single patient. In complex cases, the generation of a 3d model of the patient's anatomy allows the surgeons to better understand the case — they can almost “touch the anatomy” —, to perform a more ac- curate preoperative planning and, in some cases, to perform device positioning before going to the surgical room (i.e. joint arthroplasty). 3d printing is also commonly used to produce surgical cutting guides, these guides are positioned intraoperatively on given landmarks to guide the surgeon to perform a specific surgical act (bone osteotomy, bone resection, implant position, etc.). In total knee arthroplasty, custom-made cutting guides have been developed to help the surgeon align the femoral and tibial components to the pre-arthritic condition with- out the use of the intramedullary femoral guide. 3d printed custom-made implants represent an emerging alternative to biological reconstructions especially after oncologic resection surgery or in case of complex arthroplasty revision surgery. Custom-made implants are designed to re- place the original shape and size of the patient's bone and they allow an extreme personalization of the treatment for every single patient. Patient-specific surgical simulation is a new frontier that promises great benefits for surgical training. a solid 3d model of the patient's anatomy can faithfully reproduce the surgical complexity of the patient and it allows to generate surgical simulators with increasing difficulty to adapt the difficulties of the course with the level of the trainees performing structured training paths: from the “simple” case to the “complex” case

An overview about 3D printing technology in orthopaedic applications will be given based on examples. The process from early prototypes to certified implants coming from serial production will be demonstrated also considering relevant surrounding conditions. Today's focus is mostly on orthopaedic implants, but there is a high potential for new implant-related surgical instrument solutions taking into account up-coming clinical demands and user needs accessible by actual 3D printing technologies

Conventional 3D printing by itself is incapable of creating pores on a micro scale within deposited filaments throughout 3D scaffolds. These pores and hence larger surface areas are needed for cells to be adhered, proliferated, and differentiated. The aim of this work was to fabricate 3D polycaprolactone (PCL) scaffolds with internal multiscale porosity by using two different 3D printing techniques (ink/pellet of polymer-salt composite in low/high temperature printing) combined with salt leaching to improve cell adhesion, and cell proliferation besides to change degradation rate of PCL scaffolds:. 1. Non-solvent phase separation integrated 3D printing of polymer-salt inks with various salt content (i.e., low temperature ink-based printing, LT). 2. FDM printing of composite polymer-salt pellets which will be obtained by casting and evaporating of prepared ink (i.e., high temperature composite-pellet-based printing, HT). Further, the two approaches were followed by post salt leaching. Stem cells were able to attach on the surface and grow up to 14 days based on increasing cellular activities

3D printing can be used for the regeneration of complex tissues with intricate 3D microarchitecture. Trabecular bone is a complex and porous structure with a high degree of anisotropy. Changes in bone microarchitecture are associated with pathologies such as osteoporosis [1]. The objective of this study is to determine the viability of using 3D printing to replicate trabecular bone structures with a good control over the microarchitecture and mechanical properties. Cylindrical samples of bovine trabecular bone were used in this study. Micro-computed tomography (microCT) was carried out and an isotropic voxel size of 22 µm was obtained (Xradia Versa 520, Zeiss, USA). After 3D reconstruction the main microstructure characteristics were analysed using ImageJ (NIH, US). The 3D printed bone replicas were created by segmenting the microCT imaged bone tissue and then converted into a STL file using Avizo (FEI, US). The 3D printer used for this study was the ProJet 5500X (3D Systems, US), which allows a number of different materials to be printed in the same built with a resolution of 25 µm. Preliminary results were obtained using one single material (VisiJet CR-WT, Tensile Modulus: 1–1.6 GPa, Tensile Strength: 37–47 MPa). The 3D printed bone replicas followed a critical cleaning step to remove any remaining support material in the pores. MicroCT was then carried out for the bone replicas obtaining the same isotropic voxel size as for their biological counterparts. ImageJ was used to obtain the main microstructure characteristics. The values of bone volume fraction (BV/TV), mean trabecular thickness (Tb.Th), mean trabecular spacing (Tb.Sp), and degree of anisotropy (DA) were measured for bone samples and their 3D printed replicas [2]. Preliminary results on the first bone sample with its 3D printed replica showed similar apparent trabecular structures. Their respective BV/TV was found to be 0.24 (bone) and 0.43 (replica). The Tb.Th and Tb.Sp were 0.222 mm and 0.750 mm respectively for the bone and 0.376 mm and 0.575 mm for the replica. Finally, their respective DA was found to be 0.68 (bone) and 0.66 (replica). The main microstructure characteristics analyzed showed some differences between the bone sample and the 3D printed replica. In particular, the 3D microstructures resulted over-dimensioned mainly due to factors such as microCT voxel size, resolution of the 3D printer and supporting material removal. However this is a preliminary investigation. Further analysis will focus on optimizing the microCT imaging as well as the 3D printing process to achieve more accurate bone replicas. In addition, multi-material printing will be employed to optimize some of the mechanical properties obtained through in situ microCT testing and FE subject-specific modelling

While the COVID-19 pandemic highlighted the need for more accessible anatomy instruction tools, it is also well known that the time allocated to practical anatomy teaching has reduced in the past decades. Notably, the opportunity for anatomy students to learn osteology is not prioritised, nor is the ability of students to appreciate osteological variation. As a potential method of increasing accessibility to bone models, this study describes the process of developing 3D-printed replicas of human bones using a combination of structured light scanning (SLS) technology and 3D printing. Human bones were obtained from the Anatomy Lab at the University of Edinburgh and were digitised using SLS via an Einscan H scanner. The resulting data was then used to print multiple replicas of varying materials, colours, scales and resolutions on an Ultimaker S3 3D printer. To gather opinion on these models and their variables, surveys were completed by anatomy students and educators (n=57). Data was collected using a Likert scale response, as well as free-text answers to gather qualitative information. 3D scans of the scapula, atlas (C1 vertebrae) and femur were successfully obtained. Plastic replicas were produced with defined variables in 4 separate stations e.g. different colours, to obtain results from survey respondents. For colour, 87.7% of survey respondents preferred white models, with 7% preferring orange and 5.3% preferring blue. For material, 47.4% of respondents preferred PLA (Polylactic acid), while 33.3% preferred ABS (Acrylonitrile butadiene styrene), 12.3% preferred Pet-G (Polyethylene terephthalate glycol), 3.5% preferred Glassbend and 3.5% had no preference. Additional results based on scale and resolution were also collected. This initial study has demonstrated a proof-of-concept workflow for SLS technology to be combined with 3D printing to produce plastic replicas of human bones. Our study has provided key information about the colour, scale, material and resolution required for these models. Our future work will focus on determining accuracy of the models and their use as teaching aids for osteology education

A complete design-manufacturing process for delivering customized foot orthoses by means of digital technologies is presented. Moreover, this feasibility study aims to combine a semi-automatic modelling approach with the use of low-cost devices for 3D scanning and 3D printing. In clinical practice, traditional methods for manufacturing customized foot orthoses are completely manual, mainly based on plaster casting plus hand fabrication, and are widely used among practitioners. Therefore, results depend on skills and expertise of individual orthoptists and podiatrists that need considerable training and practice in order to obtain optimal functional devices. On the other side, novel approaches for design and manufacturing customized foot orthoses by means of digital technologies (generally based on 3D scanning, 3D modelling and 3D printing) are recently reported as a valid alternative method to overcome these limitations. This study has been carried out in an interdisciplinary approach between the staff of Design and Methods in Industrial Engineering and the staff of Podology with the aim to assess the feasibility of a novel user-friendly and cost-effective solution for delivering customized functional foot orthoses. More specifically, a Generative Design (GD) workflow has been developed to enable practitioners without enough CAD skills to easily 3D modelling and interactively customize foot orthoses. Additionally, low-cost devices for 3D scanning and 3D printing that have been acquired by the Podology Lab, were also tested and compared with the high-cost ones of the Department of Industrial Engineering. The complete process is divided into three main steps. The first one regards the digitization of the patient's foot by means of 3D laser scanner devices. Then a user-friendly 3D modelling approach, developed for this purpose as GD workflow, allows interactively generating the customized foot orthosis, also adjusting several features and exporting the watertight mesh in STL format. Finally, the last step involves Additive Manufacturing systems to obtain the expected physical item ready to use. First, for what concerns the digitizing step, the acquired data resulting from 3D scanning by means of the low-cost system (Sense 3D scanner) appears accurate enough for the present practical purposes. Then, with respect to the 3D modelling step, the proposed GD workflow in Grasshopper is intuitive and allows easily and interactively customizing the final foot orthosis. Finally, regarding the Additive Manufacturing step, the low cost 3D printer (Wasp Delta 40 70) is capable to provide adequate results for the shell of the foot orthosis. Moreover, this system appears really versatile in reason of the capability to print in a wide range of different filaments. Therefore, since the market of 3D printing filaments is rapidly growing, building sessions with different materials (both flexible and rigid such, for example, PLA, AB and PETG) were completed. This study validated, in terms of feasibility, that the use of a GD modelling approach, in combination with low-cost devices for 3D scanning and 3D printing, is a real alternative to conventional processes for providing customized foot orthosis. Moreover, the interdisciplinary approach allowed the transfer of skills and knowledge to the practitioners involved and, also, the low-cost devices Sense 3D scanner and Wasp Delta 40 70 that have been acquired by the Podology Lab, were demonstrated suitable for this kind of applications

Among the advanced technology developed and tested for orthopaedic surgery, the Rizzoli (IOR) has a long experience on custom-made design and implant of devices for joint and bone replacements. This follows the recent advancements in additive manufacturing, which now allows to obtain products also in metal alloy by deposition of material layer-by-layer according to a digital model. The process starts from medical image, goes through anatomical modelling, prosthesis design, prototyping, and final production in 3D printers and in case post-production. These devices have demonstrated already to be accurate enough to address properly the specific needs and conditions of the patient and of his/her physician. These guarantee also minimum removal of the tissues, partial replacements, no size related issues, minimal invasiveness, limited instrumentation. The thorough preparation of the treatment results also in a considerable shortening of the surgical and of recovery time. The necessary additional efforts and costs of custom-made implants seem to be well balanced by these advantages and savings, which shall include the lower failures and revision surgery rates. This also allows thoughtful optimization of the component-to-bone interfaces, by advanced lattice structures, with topologies mimicking the trabecular bone, possibly to promote osteointegration and to prevent infection. IOR's experience comprises all sub-disciplines and anatomical areas, here mentioned in historical order. Originally, several systems of Patient-Specific instrumentation have been exploited in total knee and total ankle replacements. A few massive osteoarticular reconstructions in the shank and foot for severe bone fractures were performed, starting from mirroring the contralateral area. Something very similar was performed also for pelvic surgery in the Oncology department, where massive skeletal reconstructions for bone tumours are necessary. To this aim, in addition to the standard anatomical modelling, prosthesis design, technical/technological refinements, and manufacturing, surgical guides for the correct execution of the osteotomies are also designed and 3D printed. Another original experience is about en-block replacement of vertebral bodies for severe bone loss, in particular for tumours. In this project, technological and biological aspects have also been addressed, to enhance osteointegration and to diminish the risk of infection. In our series there is also a case of successful custom reconstruction of the anterior chest wall. Initial experiences are in progress also for shoulder and elbow surgery, in particular for pre-op planning and surgical guide design in complex re-alignment osteotomies for severe bone deformities. Also in complex flat-foot deformities, in preparation of surgical corrections, 3D digital reconstruction and 3D printing in cheap ABS filaments have been valuable, for indication, planning of surgery and patient communication; with special materials mimicking bone strength, these 3D physical models are precious also for training and preparation of the surgery. In Paediatric surgery severe multi planar & multifocal deformities in children are addressed with personalized pre-op planning and custom cutting-guides for the necessary osteotomies, most of which require custom allografts. A number of complex hip revision surgeries have been performed, where 3D reconstruction for possible final solutions with exact implants on the remaining bone were developed. Elective surgery has been addressed as well, in particular the customization of an original total ankle replacement designed at IOR. Also a novel system with a high-tibial-osteotomy, including a custom cutting jig and the fixation plate was tested. An initial experience for the design and test of custom ankle & foot orthotics is also in progress, starting with 3D surface scanning of the shank and foot including the plantar aspect. Clearly, for achieving these results, multi-disciplinary teams have been formed, including physicians, radiologists, bioengineers and technologists, working together for the same goal

The aim of this study is to print 3D polycaprolactone (PCL) scaffolds at high and low temperature (HT/LT) combined with salt leaching to induced porosity/larger pore size and improve material degradation without compromising cellular activity of printed scaffolds. PCL solutions with sodium chloride (NaCl) particles either directly printed in LT or were casted, dried, and printed in HT followed by washing in deionized water (DI) to leach out the salt. Micro-Computed tomography (Micro-CT) and scanning electron microscope (SEM) were performed for morphological analysis. The effect of the porosity on the mechanical properties and degradation was evaluated by a tensile test and etching with NaOH, respectively. To evaluate cellular responses, human bone marrow-derived mesenchymal stem/stromal cells (hBMSCs) were cultured on the scaffolds and their viability, attachment, morphology, proliferation, and osteogenic differentiation were assessed. Micro-CT and SEM analysis showed that porosity induced by the salt leaching increased with increasing the salt content in HT, however no change was observed in LT. Structure thickness reduced with elevating NaCl content. Mass loss of scaffolds dramatically increased with elevated porosity in HT. Dog bone-shaped specimens with induced porosity exhibited higher ductility and toughness but less strength and stiffness under the tension in HT whereas they showed decrease in all mechanical properties in LT. All scaffolds showed excellent cytocompatibility. Cells were able to attach on the surface of the scaffolds and grow up to 14 days. Microscopy images of the seeded scaffolds showed substantial increase in the formation of extracellular matrix (ECM) network and elongation of the cells. The study demonstrated the ability of combining 3D printing and particulate leaching together to fabricate porous PCL scaffolds. The scaffolds were successfully printed with various salt content without negatively affecting cell responses. Printing porous thermoplastic polymer could be of great importance for temporary biocompatible implants in bone tissue engineering applications

Summary Statement. We are taking very expensive cutting edge technology, usually reserved for industry, and using it with the help of open source free software and a cloud 3D printing services to produce custom and anatomically unique patient individual implants for only £32. This is approx. 1/100. th. of the traditional cost of implant production. Introduction. 3D printing and rapid prototyping in surgery is an expanding technology. It is often used for preoperative planning, procedure rehearsal and patient education. There have been recent advances in orthopaedic surgery for the development of patient specific guides and jigs. The logical next step as the technology advances is the production of custom orthopaedic implants. Our aim was to use freely available open source software, a personal computer and consumer access online cloud 3D printing services to produce an accurate patient specific orthopaedic implant without utilising specialist expertise, capital expenditure on specialist equipment or the involvement of traditional implant manufacturing companies. This was all to be done quickly, cost effectively and in department. Methods & Materials. Using standard computed tomography (CT) scan and the standard file format of digital imaging and communications in medicine (DICOM) data, a 3D surface reconstruction was made of a cadaveric radial head using the software OsiriX (DICOM image processing software for Apple OS X). This data was then processed in Meshlabs (a system for the processing and editing of unstructured 3D triangular meshes) to create a mirror image 3D model of the radial head with a stem added to produce prosthesis suitable to replace the contra lateral radial head. Both packages are distributed under open-source licensing—Lesser General Public Licence (LGPL)—and are therefore free. This was then uploaded and 3D printed using a process of selective laser sintering (SLS) in stainless steel via the commercial cloud printing service . Shapeways.com. . Results & Conclusions. The model produced was an accurate mirror image replica of the patient's original anatomy (all measurements equal +/− 0.2mm using TS411212 Digital Vernier Expert Caliper 300mm P=0.001 Showing no significant statistical difference. Production from original CT scan took a total of 10 days and the total cost including shipping was £32. This was then re-implanted in to the contra lateral cadaveric radius. We achieved our aims and goals of quick, cost effective and accurate implant creation

3D printing and rapid prototyping in surgery is an expanding technology. It is often used for preoperative planning, procedure rehearsal and patient education. There have been recent advances in orthopaedic surgery for the development of patient specific guides and jigs. The logical next step as the technology advances is the production of custom orthopaedic implants. I aimed to use freely available open source software and online cloud 3D printing services to produce a patient specific orthopaedic implant without requiring the input of a university department, specialised equipment or implant companies. Using standard CT scan DICOM data, a 3D surface reconstruction was made of a patient's uninjured radial head using open source DICOM viewer OsiriX. This was then manipulated in other open source software packages called Meshlabs and Netfabb to create a mirror image 3D model of the radial head with a stem to produce a prosthesis suitable to replace the contralateral fractured radial head. This was then uploaded and printed in stainless steel via cloud printing service . Shapeways.com. . The model produced was an exact replication of the patient's original anatomy, except a mirror image suitable for replacement of the contralateral side. The process did not involve any specialist equipment or input from an academic department or implant company. It took a total of 10 days to produce and cost less than £40. From this study I was able to show that production of patient specific orthopaedic implants is possible. It also highlights that the technology is accessible to all, and does not require any special equipment or large investment. It can be achieved quickly and for a very small financial outlay. As a proof of concept it has been very successful

Collagen is a key component of the extracellular matrix in a variety of tissues and hence is widely used in tissue engineering research, yet collagen has had limited uptake in the field of 3D printing. In this study we successfully adapted an existing electronic printing method, aerosol jet printing (AJP), to print high resolution 3D constructs of recombinant collagen type III (RHCIII). Circular samples with a diameter of 4.5mm and 288 layers thick, or a diameter of 6.5mm and 400 layers thick were printed on glass cover slips with print lines of 60µm. Attenuated Total Reflectance Fourier-Transorm Infa-red (ATR-FTIR) spectroscopy performed on the 4 of the printed samples and dried non-printed RHCIII samples showed that no denaturation had occurred due to the printing process. Printed samples were crosslinked using EDC [N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, Sigma Aldrich] to improve their stability and mechanical strength. Differential scanning calorimetry (DSC) performed showed a marked difference in the denaturation temperature between crosslinked printed samples and fibrillar non-printed samples and nano-indentation showed that the construct was relatively stiff. Previous results with similar samples have shown that mesenchymal stem cells (MSCs) align with and travel parallel to print direction. Results obtained from these samples show signs that they might be applied in other areas such as bone tissue engineering

3D imaging is commonly employed in the surgical planning and management of bony deformity. The advent of desktop 3D printing now allows rapid in-house production of specific anatomical models to facilitate surgical planning. The aim of this pilot study was to evaluate the feasibility of creating 3D printed models in a university hospital setting. For requested cases of interest, CT DICOM images on the local NHS Picture Archive System were anonymised and transferred. Images were then segmented into 3D models of the bones, cleaned to remove artefacts, and orientated for printing with preservation of the regions of interest. The models were printed in polylactic acid (PLA), a biodegradable thermoplastic, on the CubeX Duo 3D printer. PLA models were produced for 4 clinical cases; a complex forearm deformity as a result of malunited childhood fracture, a pelvic discontinuity with severe acetabular deficiency following explantation of an infected total hip replacement, a chronically dislocated radial head causing complex elbow deformity as a result of a severe skeletal dysplasia, and a preoperative model of a deficient proximal tibia as a result of a severe tibia fracture. The models materially influenced clinical decision making, surgical intervention planning and required equipment. In the case of forearm an articulating model was constructed allowing the site of impingement between radius and ulnar to be identified, an osteotomy was practiced on multiple models allowing elimination of the block to supination. This has not previously been described in literature. The acetabulum model allowed pre-contouring of a posterior column plate which was then sterilised and eliminated a time consuming intraoperative step. While once specialist and expensive, in house 3D printing is now economically viable and a helpful tool in the management of complex patients

Many orthopaedic procedures require implants to be trialled before definitive implantation. Where this is required, the trials are provided in a set with the instrumentation. The most common scenario this is seen in during elective joint replacements. In Scotland (2007) the Scottish Executive (. http://www.sehd.scot.nhs.uk/cmo/CMO(2006)13.pdf. ) recommended and implemented individually packed orthopaedic implants for all orthopaedic sets. The premise for this was to reduce the risk of CJD contamination and fatigue of implants due to constant reprocessing from corrosion. During many trauma procedures determining the correct length of plate or size of implant can be challenging. Trials of trauma implants is no longer common place. Many implants are stored in closed and sealed boxes, preventing the surgeon looking at the implant prior to opening and contaminating the device. As a result many implants are incorrectly opened and either need reprocessed or destroyed due to infection control policy, thus implicating a cost to the NHS. With even the simplest implants costing several hundreds of pounds, this cost is a very significant waste in resources that could be deployed else where. My project was to develop a method to produce in department accurate, cheap and disposable trials for implants often used in trauma, where the original manufacturer do not offer the option of a trial off the shelf. The process had to not involve contaminating or destroying the original implant in the production of a trial. Several implants which are commonly used within Glasgow Royal Infirmary and do not have trials were identified. These implants were then CT scanned within their sealed and sterile packaging without contamination. Digital 3D surface renders of the models were created using free open source software (OsiriX, MeshLab, NetFabb). These models were then processed in to a suitable format for 3D printing using laser sintering via a cloud 3D printing bureau (. Shapeways.com. ). The implants were produced in polyamide PA220 material or in 316L stainless steel. These materials could be serialized using gamma irradiation or ethylene oxide gas. The steel models were suitable for autoclaving in the local CSSU. The implants produced were accurate facsimiles of the original implant with dimensions within 0.7mm. The implants were cost effective, an example being a rim mesh was reproduced in polyamide PA220 plastic for £3.50 and in 316L stainless steel for £15. The models were produced within 10 days of scanning. The stainless steel trials were durable and suitable for reprocessing and resterilisation. The production of durable, low cost and functional implant trials all completed in department was successful. The cost of production of each implant is so low that it would be offset if just one incorrect implant was opened during a single procedure. With some of the implants tested, the trials would have paid for themselves 100 times. This is a simple and cost saving technique that would help reduce department funding and aid patient care

Currently available fracture fixation devices that were originally developed for healthy bone are often not effective for patients with osteoporosis. Resulting outcomes are unsatisfactory, with longer recovery times, often requiring re-surgery for failed cases. One major issue is the design of bone screws, which can loosen or pull-out from osteoporotic bone. Design improvements are possible, but the development of new screws is a lengthy and expensive process due to the manufacture of the complex geometry involved. The aim of this research was to validate our currently available 3D printing technology in the design, manufacture and testing of screws. Three standard wood screw designs were reverse-engineered using computational modelling and then fabricated in polymeric resin using 3D rapid prototyping on a Stereolithography (SLA) machine. The original metal screws and the 3D screws (n=5 of each) were then inserted into a synthetic bone block (Sawbones, PCF5) representing the mechanical properties of severely osteoporotic cancellous bone. Pull-out tests were conducted in accordance with ASTM 543-13. The three metal screws exhibited pull-out strengths of 125, 74 and 118 N respectively. The 3D printed screws by comparison showed pull-out strengths approximately 15–20 % lower than their metal counterparts. However, when the results were normalised to the material tested, showing the relative changes to the first design, the pattern of results in the metal and 3D printed groups were almost identical (within 3 % of each other), showing excellent correlation. This study is the first to show that 3D Rapid Prototyping can be used in the pre-clinical testing of orthopaedic screws. The methodology provides a cheaper, faster development process for screws, allowing huge scope for development and improvement. Future work will include expanding the study to include more screw configurations as well as testing in higher density foams to compare performance in healthier bone

Different 3D printing techniques for orthopaedic ceramic implants fabrication were compared. Stereolithography of calcium-phosphate slurries makes possible to achieve pre-determined pore size (50 mkm and more) and porosity of 70–80%. For the first time ceramic implants based on double calcium alkali metal phosphates (rhenanites) with given architecture serving good osteoconductivity as well as high resorptivity and strength (up to 10 MPa) were obtained. Development of biomaterials based on calcium phosphates for orthopaedics is an important area of modern materials science. Chemical, physical and mechanical compatibility of this materials is a primary goal for this field. An ideal implant should gradually dissolve and be replaced by the new bone tissue in the patience body. Bone is a multilevel organic/inorganic composite and the main inorganic compound is hydroxyapatite (HA, Ca. 10. (PO. 4. ). 6. (OH). 2. ). Due to this, biomaterials based on HA are widely used, along with biomaterials based on tricalcium phosphate (TCP, Ca. 3. (PO. 4. ). 2. ); however, low solubility of HA (lowest soluble phosphate) as well as TCP does not meet all of the requirements that biomaterials should have. In this work decreasing of the crystal lattice energy approach was used as a strategy of improving the solubility. Modifying the chemical composition by replacing Ca. 2+. cation in the TCP structure by a singly charged alkali metal cation leads to structural changes from TCP to CaMPO. 4. (M=Na, K) – rhenanite. This work focuses on using double calcium alkali metal phosphates Ca. (3 – x). М. 2x. (PO. 4. ). 2. (x = 0–1, М = Na, K) as bioresorbable osteoconductive ceramic implant. Additive manufacturing techniques are the most competitive technology which has been applied in the medical field for the direct or indirect construction of scaffolds and hard or soft tissues. Different techniques were used to prepare ceramics with given structure based on double calcium alkali metals phosphates to improve its osteoconductive properties. High resolution stereolithography (SLA) of ceramic photocurable resins has a great potential in fabrication of high quality complex shaped ceramics. For the first time ceramic implants based on double calcium alkali metal phosphates (rhenanites) with pre-determined pore size (50 mkm and more) and porosity of 70–80% were obtained. Given architecture of scaffold is serving a good osteoconductivity as well as a high resorptivity and strength (up to 10 MPa). High resolution SLA can be easily used for fabrication of a small size implants (3mm in diameter/height or less) for in vivo experiments, and it can be freely used to fit any shade in osteoconductive properties of ceramic materials designed for bone grafting. Russian Science Foundation supported this study under Grant No. 14-19-00752. The authors acknowledge partial support from Lomonosov Moscow State University Program of Development

Abstract

Paediatric musculoskeletal (MSK) disorders often produce severe limb deformities, that may require surgical correction. This may be challenging, especially in case of multiplanar, multifocal and/or multilevel deformities. The increasing implementation of novel technologies, such as virtual surgical planning (VSP), computer aided surgical simulation (CASS) and 3D-printing is rapidly gaining traction for a range of surgical applications in paediatric orthopaedics, allowing for extreme personalization and accuracy of the correction, by also reducing operative times and complications. However, prompt availability and accessible costs of this technology remain a concern. Here, we report our experience using an in-hospital low-cost desk workstation for VSP and rapid prototyping in the field of paediatric orthopaedic surgery.

From April 2018 to September 2022 20 children presenting with congenital or post-traumatic deformities of the limbs requiring corrective osteotomies were included in the study. A conversion procedure was applied to transform the CT scan into a 3D model. The surgery was planned using the 3D generated model. The simulation consisted of a virtual process of correction of the alignment, rotation, lengthening of the bones and choosing the level, shape and direction of the osteotomies. We also simulated and calculated the size and position of hardware and customized massive allografts that were shaped in clean room at the hospital bone bank. Sterilizable 3D models and PSI were printed in high-temperature poly-lactic acid (HTPLA), using a low-cost 3D-printer.

Twenty-three operations in twenty patients were performed by using VSP and CASS. The sites of correction were: leg (9 cases) hip (5 cases) elbow/forearm (5 cases) foot (5 cases) The 3D printed sterilizable models were used in 21 cases while HTPLA-PSI were used in five cases. customized massive bone allografts were implanted in 4 cases. No complications related to the use of 3D printed models or cutting guides within the surgical field were observed. Post-operative good or excellent radiographic correction was achieved in 21 cases.

In conclusion, the application of VSP, CASS and 3D-printing technology can improve the surgical correction of complex limb deformities in children, helping the surgeon to identify the correct landmarks for the osteotomy, to achieve the desired degree of correction, accurately modelling and positioning hardware and bone grafts when required. The implementation of in-hospital low-cost desk workstations for VSP, CASS and 3D-Printing is an effective and cost-advantageous solution for facilitating the use of these technologies in daily clinical and surgical practice.

Abstract

Osteoporosis is a worldwide spread, silent disease steadily increasing due to demographic shift; it results in bone loss and increased porosity that lead to an increase in bone fragility and to low-energy fractures. In such a contest, we worked on the development of 3D scaffolds engineered to mimic the features of human healthy bone. Healthy and osteoporotic bone microCT scans were obtained from tissues discarded during surgical interventions (Istituto Ortopedico Rizzoli-Italy). The obtained .STL file was used to 3D print a type I collagen solution to mimic bone matrix whereas mesoporous bioactive glass/nano-hydroxyapatite were embedded within the collagen fibers to mimic the inorganic phase of human bone. The rheological properties of the Type I collagen/mesoporous glass suspensions were investigated at different collagen concentration and temperatures. The possibility of incorporating growth factors (IGF and β-TGF) in the scaffold struts was investigated proposing several approaches and their retained activity was assessed. Different co-culture of osteoblasts and osteoclasts set-ups were explored in order to define the influence of both chemical and topographical stimuli on the osteoblast-osteoclast coupling.

Objective

To analyze the short-term outcome after medial open-wedge high tibial osteotomy with a 3D-printing technology in early medial keen osteoarthritis and varus malalignment.