In this study, metal 3D printing technology was used to create lattice-shaped test specimens of orthopedic implants to determine the effect of different lattice shapes on bone ingrowth. Six different lattice shapes were used: gyroid, cube, cylinder, tetrahedron, double pyramid, and Voronoi. The lattice-structured implants were produced from Ti6Al4V alloy using direct metal laser sintering 3D printing technology with an EOS M290 printer. The implants were implanted into the femoral condyles of sheep, and the animals were euthanized 8 and 12 weeks after surgery. To determine the degree of bone ingrowth for different lattice-shaped implants, mechanical, histological, and image processing tests on ground samples and optical microscopic images were performed. In the mechanical test, the force required to compress the different lattice-shaped implants and the force required for a solid implant were compared, and significant differences were found in several instances. Statistically evaluating the results of our image processing algorithm, it was found that the digitally segmented areas clearly consisted of ingrown bone tissue; this finding is also supported by the results of classical histological processing. Our main goal was realized, so the bone ingrowth efficiencies of the six lattice shapes were ranked. It was found that the gyroid, double pyramid, and cube-shaped lattice implants had the highest degree of bone tissue growth per unit time. This ranking of the three lattice shapes remained the same at both 8 and 12 weeks after euthanasia. In accordance with the study, as a side project, a new image processing algorithm was developed that proved suitable for determining the degree of bone ingrowth in lattice implants from optical microscopic images. Along with the cube lattice shape, whose high bone ingrowth values have been previously reported in many studies, it was found that the gyroid and double pyramid lattice shapes produced similarly good results.

All types of cranioplasty techniques restore the morphology of the skull and affect patient aesthetics. Safe and easy techniques are required to enhance patients’ recovery and the rehabilitation process. We propose a new method of cranioplasty. The 3-dimensional (3D) reconstruction of a thin-layer computed tomography (CT) scan of the skull was used to reflect the intact side onto the defect and subtract the overlapping points from one another. In this way, a 3D model of the planned implant can be built in the required shape and size. The precise fit of the implant can be checked by printing the defective part of the skull in case it can be modified. A sterilisable silicone mould based on the finalized model was created afterwards. Polymethyl methacrylate implants were prepared directly in an aseptic environment in the operating room during surgery. Between 2005 and 2020, we performed 54 cranioplasties on 52 patients whose craniotomies were performed previously for indications of traumatic brain injury, stroke or tumour surgeries. No technical problems were noted during the operations. In 2 cases, septic complications that occurred were not connected to the technique itself, and the implants were removed and later replaced. Our proposed technique based on 3D-printed individual silicone moulds is a reliable, safe, easily reproducible and low-cost method to repair different skull defects.

In the nearly 120 years of aviation history, the industry and technology have evolved with the world. In the early decades, the focus was on preparing aircraft for passenger transport, and gradually the industry developed different areas such as airports, navigation, in-flight services and air traffic control. The aviation industry has faced quite many challenges in different periods. At the beginning of the JET era, the first very controversial factor, noise pollution, was already apparent. The gas turbines of the time were much less efficient than today’, and although the technology worked, some factors were less considered by developers, such as the noise and environmental impact mentioned above. As we moved into more modern times, the focus shifted more and more to the pollutants emitted by aircraft, which has become one of the most studied factors to date. This research examines the sustainability of aviation, past, present and future, in the light of global warming. It presents technologies that already work in the present, but their possible spread only points to the near or even distant future.

A koponyacsont veleszületett, vagy szerzett hiányainak pótlása az intracraniális tér különleges fizikai és élettani viszonyai miatt rendkívül fontos. Nem hanyagolható el a műtét esztétikai hatása sem. Az intézetünkben kidolgozott cranioplasztikai eljárás folyamán, a koponyáról készült vékony réteg CT felvételek 3D rekonstrukciója során az ép oldalt szoftveresen a sérült régióra tükrözzük, majd az átfedő pontokat kivonjuk egymásból. Így előállítható a defektus pótlására alkalmas alak-és méretpontos 3D modell. A sérült koponyarészletet kinyomtatva a pótlás pontos illeszkedése könnyen ellenőrizhető, probléma esetén a modell módosítható. A végleges modellről sterilizálható szilikon öntőmintát készítünk, melynek felhasználásával műtét közben a megfelelő pótlás poly(methyl methacrylate) (PMMA) alapú csontcementből steril körülmények között kiönthető és beültethető. 2013-tól 2020-ig a Szegedi Tudományegyetem Általános Orvostudományi Karának Idegsebészeti Tanszékével és a Magyar Honvédség Egészségügyi Központ Honvédkórház Idegsebészeti Osztályával együttműködve 51 esetben készítettünk ezzel a módszerrel cranioplasztika öntőformát. Műtéttechnikai probléma nem volt. 2 beteg esetében 3 pótlást érintően lépett fel szeptikus, a bemutatott implantátum-előállító eljárástól független szövődmény, emiatt a pótlások eltávolítására kényszerültünk. Véleményünk szerint a 3D nyomtatási technológiával előállított szilikon öntőformában, csontcementből készülő egyedi implantátumok igen jó eredménnyel alkalmazhatóak a koponya csontos hiányainak pótlására.

Background: Surgeries of severe periacetabular bone defects (Paprosky ≥ 2B) are a major challenge in current practice. Although solutions are available for this serious clinical problem, they all have their disadvantages as well as their advantages. An alternative method of reconstructing such extensive defects was the use of a cup with a stem to solve these revision situations. As the instrumentation offered is typically designed for scenarios where a significant bone defect is not present, our unique technique has been developed for implantation in cases where reference points are missing. Our hypothesis was that a targeting device designed based on the CT scan of a patient’s pelvis could facilitate the safe insertion of the guiding wire. Methods: Briefly, our surgical solution consists of a two-step operation. If periacetabular bone loss was found to be more significant during revision surgery, all implants were removed, and two titanium marker screws in the anterior iliac crest were percutaneously inserted. Next, by applying the metal artifact removal (MAR) algorithm, a CT scan of the pelvis was performed. Based on that, the dimensions and positioning of the cup to be inserted were determined, and a patient-specific 3D printed targeting device made of biocompatible material was created to safely insert the guidewire, which is essential to the implantation process. Results: In this study, medical, engineering, and technical tasks related to the design, the surgical technique, and experiences from 17 surgical cases between February 2018 and July 2021 are reported. There were no surgical complications in any cases. The implant had to be removed due to septic reasons (independently from the technique) in a single case, consistent with the septic statistics for this type of surgery. There was not any perforation of the linea terminalis of the pelvis due to the guiding method. The wound healing of patients was uneventful, and the implant was fixed securely. Following rehabilitation, the joints were able to bear weight again. After one to four years of follow-up, the patient satisfaction level was high, and the gait function of the patients improved a lot in all cases. Conclusions: Our results show that CT-based virtual surgical planning and, based on it, the use of a patient-specific 3D printed aiming device is a reliable method for major hip surgeries with significant bone loss. This technique has also made it possible to perform these operations with minimal X-ray exposure.

Célkitűzés: Munkánk célja biopolimer bázisú 3D nyomtatható hidrogél előállításának, pásztázó elektronmikroszkópos (PEM)vizsgálatainak és biokompatibilitásának bemutatása.Anyagok és módszerek: Ansys SpaceClaim (Ansys Inc, USA) 3D modellező szoftver segítségével 1 és 2 mm vastagságúmintákat terveztünk, majd biodegradábilis metakrilált poli-γ-glutaminsav (MPGA) alapon hidrogéleket állítottunkelő sztereolitográfia (SLA) típusú Form 2 (Formlabs Inc, USA) 3D nyomtató alkalmazásával. A hidrogélek felületétés szerkezetét sztereo- és elektronmikroszkóp segítségével vizsgáltuk. A 3D nyomtatott hidrogélek biokompatibilitásátMG63 sejtvonalon Alamar blue teszt felhasználásával bizonyítottuk, és a minták felületén növesztett sejtek PEM felvételeinkeresztül mutattuk be.Eredmények: Eredményeink bizonyították, hogy az MPGA alapú hidrogélek nyomtathatóak SLA technikájú 3D nyomtatósegítségével. A nyomatás útján kialakított hidrogélek néhány száz nanométeres hálószerű struktúrájúak. Az Alamarblue teszt bizonyította, hogy ugyan 1 nap elteltével csökkent az MG63 sejtek száma a felületen, de 3 nappal későbba kontrollhoz viszonyítva különbség már nem volt kimutatható. Mindezen túl a PEM felvételek is bizonyítják a sejtek kötődéséta hidrogél felületéhez.Következtetés: Az általunk előállított MPGA alapú polimer rendszer SLA technikával nyomtathatónak bizonyult. A kialakítottbiokompatibilis, nanostruktúrált hidrogélek ígéretes jelöltek a biológiailag aktív komponensek szállítására a szövettervezésterületén.