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Highly porous titanium foams are great candidates for replacing bone structures with a low elastic modulus owing to their ability to avoid the stress shielding effect. However, the production of highly porous foams (>70 vol.%) with well-distributed, stable, and predictable porous architectures using powder compaction and space holders is challenging. In this study, pure titanium powder and mechanically alloyed Ti-13Ta-6Sn were mixed with 50, 70, and 80 vol.% KCl powders as a space holder, cold-compacted, and sintered in a plasma-assisted sintering reactor to produce highly porous foams. The space holder was completely removed using heat and plasma species collisions prior to sintering. A Ti-13Ta-6Sn alloy powder with α, β, and metastable FCC-γ phases was synthesized. The characteristics of the alloyed powder, mixing step, and the resulting sintered samples were compared to those of CP-Ti. After sintering, the alloy exhibited α and β phases and a reduced elastic modulus. Foams with an elastic modulus in the range of the cortical and trabecular bones were obtained. The results showed the effects of the space holder volume fractions on the volume fraction, size, distribution, interconnectivity, and shape of the pores. The Ti-13Ta-6Sn foams exhibited a uniform open-celled porous architecture, lower elastic modulus, higher yield strength, and higher passivation resistance than CP-Ti. Ti-13Ta-6Sn exhibited a nontoxic effect for the mouse fibroblast cell line. [ABSTRACT FROM AUTHOR]

Aims: The efficacy of saline irrigation for treatment of implant-associated infections is limited in the presence of porous metallic implants. This study evaluated the therapeutic efficacy of antibiotic doped bioceramic (vancomycin/tobramycin-doped polyvinyl alcohol composite (PVA-VAN/TOB-P)) after saline wash in a mouse infection model implanted with titanium cylinders. Methods: Air pouches created in female BalBc mice by subcutaneous injection of air. In the first of two independent studies, pouches were implanted with titanium cylinders (400, 700, and 100 µm pore sizes) and inoculated with Staphylococcus aureus (1 × 103 or 1 × 106 colony-forming units (CFU)/pouch) to establish infection and biofilm formation. Mice were killed after one week for microbiological analysis. In the second study, pouches were implanted with 400 µm titanium cylinders and inoculated with S. aureus (1 × 103 or 1 × 106 CFU/pouch). Four groups were tested: 1) no bacteria; 2) bacteria without saline wash; 3) saline wash only; and 4) saline wash plus PVA-VAN/TOB-P. After seven days, the pouches were opened and washed with saline alone, or had an additional injection of PVA-VAN/TOB-P. Mice were killed 14 days after pouch wash. Results: The first part of the study showed that low-grade infection was more significant in 400 µm cylinders than cylinders with larger pore sizes (p < 0.05). The second part of the study showed that saline wash alone was ineffective in eradicating both low- and high-grade infections. Saline plus PVA-VAN/TOB-P eradicated the titanium cylinder-associated infections, as manifested by negative cultures of the washouts and supported by scanning electron microscopy and histology. Conclusion: Porous titanium cylinders were vulnerable to bacterial infection and biofilm formation that could not be treated by saline irrigation alone. Application of PVA-VAN/TOB-P directly into the surgical site alone or after saline wash represents a feasible approach for prevention and/or treatment of porous implant-related infections. Cite this article: Bone Joint Res 2024;13(11):622–631.

Excessive inflammation caused by bacterial infection is the primary cause of implant failure. Antibiotic treatment often fails to prevent peri-implant infection and may induce unexpected drug resistance. Herein, a non-antibiotic strategy based on the synergy of silver ion release and macrophage reprogramming is proposed for preventing infection and bacteria-induced inflammation suppression by the organic-inorganic hybridization of silver nanoparticle (AgNP) and quercetin (Que) into a polydopamine (PDA)-based coating on the 3D framework of porous titanium (SQPdFT). Once the planktonic bacteria (e.g., Escherichia coli, Staphylococcus aureus) reach the surface of SQPdFT, released Que disrupts the bacterial membrane. Then, AgNP can penetrate the invading bacterium and kill them, which further inhibits the biofilm formation. Simultaneously, released Que can regulate macrophage polarization homeostasis via the peroxisome proliferators-activated receptors gamma (PPARγ)-mediated nuclear factor kappa-B (NF-κB) pathway, thereby terminating excessive inflammatory responses. These advantages facilitate the adhesion and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs), concomitantly suppressing osteoclast maturation, and eventually conferring superior mechanical stability to SQPdFT within the medullary cavity. In summary, owing to its excellent antibacterial effect, immune remodeling function, and pro-osteointegration ability, SQPdFT is a promising protective coating for titanium-based implants used in orthopedic replacement surgery.

AbstractPorous titanium exhibits excellent mechanical properties and clarifying its dynamic deformation behavior with the rate-temperature effect can offer the significant insights for the structural design of materials. This article delves into the coupling effect of rate and temperature, as well as the local deformation mechanisms of porous titanium subjected to high-temperature and high-strain-rate conditions (−823 K and −8000/s, respectively). A dynamic balance formula for rate-temperature competition has been introduced for application in high-temperature and high-strain-rate conditions. The local relative deformation observed at the end face exceeds 300% than other regions, while the degree of end surface densification reaches 61.5%. [ABSTRACT FROM AUTHOR]

Periprosthetic joint infection remains a major problem. The bactericidal efficacy of commercial irrigation solutions for the treatment of infection is not well established in the presence of porous titanium (Ti) implants. This study compared the in vitro efficacy of five irrigation solutions on infected three-dimensional–printed porous Ti discs. Titanium discs (2 × 4 mm, 400, 700, and 1,000 μm) were infected with S. aureus (1 × 106 colony-forming unit/mL) and incubated for 3 hours or 3 days to create acute or chronic infection with biofilm. Discs were irrigated with saline, antibiotic, or antiseptic solutions, then repeatedly sonicated. Sonicates were cultured for bacterial quantification. Statistical analyses were performed using one-way analysis of variance (ANOVA), followed by Tukey-Kramer post hoc testing (P <.05 significance). Biofilms were visualized by scanning electron microscopy. Saline irrigation was ineffective in both groups. In acute infections with 400 μm pores, differences were found with saline versus solution #3 (P =.015) and #4 (P =.015). Solution #4 had the lowest bacterial counts for all pore sizes. For biofilm, irrigation with saline, solutions #1, #2, and #3 inadequately cleared bacteria in all pore sizes. Lower remaining concentrations were observed in #4 with 400μm pores compared to saline (P =.06) and #2 (P =.039). The scanning electron microscopy showed a reduction of biofilm in samples washed with #4. Irrigation of infected porous Ti discs with saline, solutions #1 and #2 failed to reduce the bacterial load. The 400 μm discs consistently had more bacteria despite irrigation, highlighting the difficulty of removing bacteria from small pores. Solutions #3 and #4 reduced bacteria acutely, but only #4 demonstrated efficacy in clearing biofilm compared to saline. These results should be considered when treating periprosthetic joint infection in the presence of porous components and the potential presence of biofilm. [ABSTRACT FROM AUTHOR]

Copyright of Iron Steel Vanadium Titanium is the property of Iron Steel Vanadium Titanium Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The microstructure, elastoplastic properties, and corrosive response of induced porous Ti-TiH2 materials reinforced with TiB2 particles were investigated. Samples were fabricated using CP-Ti Grade1, Titanium Hydride (TiH2), TiB2 powders (0, 3, 10, and 30 vol.%), and ammonium bicarbonate salt (40 vol.%) as a space holder. Composites were fabricated using the Powder Metallurgy technique under high-vacuum conditions (HVS) at 1100 °C. Scanning electron microscopy, X-ray diffraction, nanoindentation tests, and electrochemical assays were used to investigate the pore formation, pore distribution, phase formation, elastoplastic properties, and electrochemical behavior of the compounds, respectively. With a mean pore diameter of 50–900 µm and Young's modulus of less than 100 GPa, which is close to the properties of human bone, the pore structures of the compounds processed here are shown to be a potential biomaterial for osseointegration. In addition, their H / E r and H 3 / E r 2 ratios for the reinforced samples are higher than those of the unreinforced sample (1.5 and 4 times higher than the unreinforced sample, respectively), suggesting a better wear resistance of the Ti-TiH2/xTiB2 composites. Electrochemical experiments demonstrated that the Ti-TiH2/xTiB2 composites exhibited superior passivation properties compared to the Ti-TiH2 sample. Additionally, the corrosion rates exhibited by the 3 and 10 vol.% of TiB2 samples were found to be within an acceptable range for potential biomedical applications (29.26 and 185.82 E-3 mm·y−1). The elastoplastic properties combined with the electrochemical behavior place the Ti-TiH2/3-10TiB2 composites as potential candidates for the biomedical application of CP-Ti. [ABSTRACT FROM AUTHOR]

Porous titanium exhibits low elastic modulus and porous structure is thought to be a promising implant in bone defect repair. However, the bioinert and low mechanical strength of porous titanium have limited its clinical application, especially in load‐bearing bone defect repair. Our previous study has reported an infiltration casting and acid corrosion (IC‐AC) method to fabricate a novel porous titanium (pTi) with 40% porosity and 0.4 mm pore diameter, which exerts mechanical property matching with cortical bone and interconnected channels. In this study, we introduced a nanoporous coating and incorporated an osteogenic element strontium (Sr) on the surface of porous titanium (named as Sr‐micro arch oxidation [MAO]) to improve the osteogenic ability of the pTi by MAO. Better biocompatibility of Sr‐MAO was verified by cell adhesion experiment and cell counting kit‐8 (CCK‐8) test. The in vitro osteogenic‐related tests such as immunofluorescence staining, alkaline phosphatase staining and real‐time polymerase chain reaction (RT‐PCR) demonstrated better osteogenic ability of Sr‐MAO. Femoral bone defect repair model was employed to evaluate the osseointegration of samples in vivo. Results of micro‐CT scanning, sequential fluorochrome labeling and Van Gieson staining suggested that Sr‐MAO showed better in vivo osteogenic ability than other groups. Taking results of both in vitro and in vivo experiment together, this study indicated the Sr‐MAO porous titanium could be a promising implant load‐bearing bone defect. [ABSTRACT FROM AUTHOR]

Medicine is looking for solutions to help implant patients recover more smoothly. The porous implants promote osteointegration, thereby providing better stabilization. Introducing porosity into metallic implants enhances their biocompatibility and facilitates osteointegration. The introduction of porosity is also associated with a reduction in Young's modulus, which reduces the risk of tissue outgrowth around the implant. However, the risk of chronic inflammation remains a concern, necessitating the development of coatings to mitigate adverse reactions. An interesting biomaterial for such modifications is chitosan, which has antimicrobial, antifungal, and osteointegration properties. In the present work, a porous titanium biomaterial was obtained by powder metallurgy, and electrophoretic deposition of chitosan coatings was used to modify its surface. This study investigated the influence of ethanol content in the deposition solution on the quality of chitosan coatings. The EPD process facilitates the control of coating thickness and morphology, with higher voltages resulting in thicker coatings and increased pore formation. Ethanol concentration in the solution affects coating quality, with higher concentrations leading to cracking and peeling. Optimal coating conditions (30 min/10 V) yield high-quality coatings, demonstrating excellent cell viability and negligible cytotoxicity. The GIXD and ATR-FTIR analysis confirmed the presence of deposited chitosan coatings on Ti substrates. The microstructure of the chitosan coatings was examined by scanning electron microscopy. Biological tests showed no cytotoxicity of the obtained materials, which allows for further research and the possibility of their use in medicine. In conclusion, EPD offers a viable method for producing chitosan-based coatings with controlled properties for biomedical applications, ensuring enhanced patient outcomes and implant performance. [ABSTRACT FROM AUTHOR]

Biomaterials are the basis for the development of medicine because they allow safe contact with a living organism. The aim of this work was to produce innovative oxide layers with a microporous structure on the surface of commercially pure titanium Grade 4 (CpTi G4) and to characterize their properties as drug carriers. The anodization of the CpTi G4 subjected to mechanical grinding and electrochemical polishing was carried out in a solution of 1M ethylene glycol with the addition of 40 g of ammonium fluoride at a voltage of 20 V for 2, 18, 24, and 48 h at room temperature. It was found that the longer the anodization time, the greater the number of pores formed on the CpTi G4 surface as revealed using the FE-SEM method, and the greater the surface roughness determined in profilometric tests. As the anodizing time increases, the amount of the drug in the form of gentamicin sulfate incorporated into the resulting pores decreases. The most favorable drug release kinetics profile determined via UV–VIS absorption spectroscopy was found for the CpTi G4 anodized for 2 h. [ABSTRACT FROM AUTHOR]

IntroductionThe assessment of segmental fusion after Lateral Lumbar Interbody fusion (LLIF) using 3D-printed porous titanium cage is still not well studied. Various criteria, such as the presence of bone bridges (BB) between adjacent vertebrae, serve as indicators for anterior fusion. However, limited radiological studies have investigated zygapophyseal joints (ZJ) status following LLIF with porous titanium cages vs. conventional titanium threaded cages. The porous design of the latest titanium intervertebral cages is thought to enhance the bone-to-implant fusion rate. This radiological study aimed to compare the fusion patterns post-LLIF using 3D-printed porous titanium cages against those using threaded titanium cages. This radiological study aimed to compare the fusion patterns after LLIF using 3D-printed porous titanium cages against those using threaded titanium cages.Material and methodsThis retrospective, single-center radiological study involved 135 patients who underwent LLIF and posterior percutaneous screw fixation for degenerative spondylolisthesis. The study included 51 patients (Group A) with the novel porous titanium cages and 84 patients (Group B) with conventional threaded titanium cages. Inclusion criteria mandated complete radiological data and a minimum follow-up period of 24 months. The study evaluated intervertebral bone bridges (BB) for anterior fusion and zygapophyseal joints (ZJ) ankylotic degeneration, based on Pathria et al., as evidence of posterior fusion and segmental immobilization.ResultsTwo years after surgery, intervertebral BB were identified in 83 segments (94.31%) in Group A and in 87 segments (88.77%) in Group B. ZJ Pathria grade I was observed in 2 segments (2.27%) of Group A and in 4 segments (4.08%) of Group B. Grade II was seen in 5 segments (5.68%) of Group A and in 6 segments (6.12%) of Group B. Posterior fusion, classified as grade III, was found in 81 segments (92.04%) of Group A and 88 segments (89.79%) of Group B. Subsidence incidence was 5.88% (3 segments) for the novel cage and 9.88% (8 segments) for the conventional cage.ConclusionsThe architecture of porous titanium cages offers a promising solution for increasing bone ingrowth and bridging space, supporting successful spinal fusion while minimizing the risk of subsidence.

Artificial bone porous titanium materials are widely used in orthopedic implants. However, the traditional constitutive model is often limited by the complexity and accuracy of the model, and it is difficult to accurately and efficiently describe the constitutive relationship of porous titanium materials. In this study, structured data were established based on experimental data from published papers, and goodness of fit ( R 2 ), mean absolute error ( M A E ) and mean absolute percentage error ( M A P E ) were used to evaluate the model. The prediction effect of random forest (RF), multi-layer perceptron (MLPR) and support vector machine (SVR) on the constitutive relationship of porous titanium materials was discussed. Through comprehensive comparison, it can be seen that the RF model with max_depth of 24 and n_estimators of 160 has the best performance in prediction, and the average absolute percentage error is less than 4.4%, which means it can accurately predict the temperature sensitivity and strain rate sensitivity of porous titanium materials. And its predictive ability is better than that of the traditional constitutive model, which provides a new idea and method for the constitutive modeling of porous titanium materials. [ABSTRACT FROM AUTHOR]

This study aimed to compare the push-out bond strength (PBS) between a new porous titanium post (PTP) and other marketed dental posts cemented with two types of dual-cure resin cement. A total of 96 extracted single-rooted human teeth were recruited. Four types of dental posts (n = 24 each), namely: stainless steel post (SSP), commercially-pure titanium post (CTP), fibre glass post (FGP), and PTP were cemented with two types of resin cements (RelyX U200 and ParaCore) and then sectioned at coronal and middle root levels. The specimens were subjected to a PBS test at a crosshead speed of 0.5 mm/min. The interface analysis was performed using a stereomicroscope and scanning electron microscope. A p-value < 0.05 was considered significant for all statistical tests. PBS recordings showed that the highest PBS mean value in RelyX group was 2.68±1.10 MPa for PTP. The differences in PBS between PTP and SSP and FGP were not significant (p = 0.098 and p = 0.075, respectively). The null hypothesis for RelyX group at both coronal and middle sections of the root was retained (p > 0.05). No failure at the post-cement interface was found in the PTP group, which was founder superior over the other posts (no gap for this interface was observed). The PTP showed similar bonding strength and adhesion to the other tested posts when using RelyX U200 cement. The PTP can be considered a new alternative option for the dental post system. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highly porous titanium foams are great candidates for replacing bone structures with a low elastic modulus owing to their ability to avoid the stress shielding effect. However, the production of highly porous foams (>70 vol.%) with well-distributed, stable, and predictable porous architectures using powder compaction and space holders is challenging. In this study, pure titanium powder and mechanically alloyed Ti-13Ta-6Sn were mixed with 50, 70, and 80 vol.% KCl powders as a space holder, cold-compacted, and sintered in a plasma-assisted sintering reactor to produce highly porous foams. The space holder was completely removed using heat and plasma species collisions prior to sintering. A Ti-13Ta-6Sn alloy powder with α, β, and metastable FCC-γ phases was synthesized. The characteristics of the alloyed powder, mixing step, and the resulting sintered samples were compared to those of CP-Ti. After sintering, the alloy exhibited α and β phases and a reduced elastic modulus. Foams with an elastic modulus in the range of the cortical and trabecular bones were obtained. The results showed the effects of the space holder volume fractions on the volume fraction, size, distribution, interconnectivity, and shape of the pores. The Ti-13Ta-6Sn foams exhibited a uniform open-celled porous architecture, lower elastic modulus, higher yield strength, and higher passivation resistance than CP-Ti. Ti-13Ta-6Sn exhibited a nontoxic effect for the mouse fibroblast cell line.

Porous titanium was prepared by metal injection molding (MIM) and high vacuum sintering using polymethyl methacrylate (PMMA) particles as pore forming agent and polyformaldehyde (POM) as main binder. The effects of PMMA and sintering temperature on the pore characteristics of porous titanium were investigated in detail. The results showed that PMMA particles are melted and mixed with organic binder together and lose their original particle characteristics (particle size and shape) during kneading. In the process of thermal debinding, PMMA decompose before high-density polyethylene (HDPE) in the temperature range of 350～420 ℃, which play the role of pore formation, but the shape of pores was irregular and the pore sizes are much smaller than the original PMMA particle sizes. In the sintering temperature range of 1100～1250 ℃, the opening porosity and pore sizes of porous titanium decrease with increasing of sintering temperature. When the sintering temperature is 1150～1200 ℃, the opening porosity of porous titanium is 34%～35%, and the pore size is about 9.1 μm.

The utilization of porous biomedical implants featuring a bimodal microstructure has garnered substantial interest within the scientific community. This study delves into the intricate interplay between processing parameters, microstructural attributes, and the tribo-mechanical performance of titanium grade 4, showcasing its potential to serve as implants to address compromised cortical bone tissue. The investigation meticulously examines the impact of milling duration (10 and 20 h), proportion of milled powder (50 and 75 wt%), and the volume fraction of space-holding agents (40–60 vol% NaCl) on the resulting characteristics of the bimodal microstructure, which plays a crucial role in achieving optimal biomechanical equilibrium. The Vickers microhardness, conventional and instrumented (P-h curves), and the wear behavior (ball-on disk) are discussed in terms of bimodal microstructure distribution, particle size and porosity level inherent to the fabrication conditions (mechanical milling + space-holder + hot-pressing). In general terms, milling time and milled powder fraction were the most influent parameters on the final properties of the materials. With the processing route used, the achieved microhardness values and wear behavior are comparable with those obtained by means of surface modifications or alloys. The Young's moduli obtained were in the range of 30–50 GPa, which could help to reduce the shielding phenomenon, while presenting a good mechanical resistance and wear behavior. In light of these findings, the fabricated specimen, composed of 75 wt% milled powder subjected to a 10-h milling duration, supplemented by a 60 vol% fraction of NaCl, emerges as a prime candidate manifesting superior biomechanical equilibrium. This judicious configuration exhibits a promising trajectory for its application in bone replacement endeavors.

Medicine is looking for solutions to help implant patients recover more smoothly. The porous implants promote osteointegration, thereby providing better stabilization. Introducing porosity into metallic implants enhances their biocompatibility and facilitates osteointegration. The introduction of porosity is also associated with a reduction in Young’s modulus, which reduces the risk of tissue outgrowth around the implant. However, the risk of chronic inflammation remains a concern, necessitating the development of coatings to mitigate adverse reactions. An interesting biomaterial for such modifications is chitosan, which has antimicrobial, antifungal, and osteointegration properties. In the present work, a porous titanium biomaterial was obtained by powder metallurgy, and electrophoretic deposition of chitosan coatings was used to modify its surface. This study investigated the influence of ethanol content in the deposition solution on the quality of chitosan coatings. The EPD process facilitates the control of coating thickness and morphology, with higher voltages resulting in thicker coatings and increased pore formation. Ethanol concentration in the solution affects coating quality, with higher concentrations leading to cracking and peeling. Optimal coating conditions (30 min/10 V) yield high-quality coatings, demonstrating excellent cell viability and negligible cytotoxicity. The GIXD and ATR-FTIR analysis confirmed the presence of deposited chitosan coatings on Ti substrates. The microstructure of the chitosan coatings was examined by scanning electron microscopy. Biological tests showed no cytotoxicity of the obtained materials, which allows for further research and the possibility of their use in medicine. In conclusion, EPD offers a viable method for producing chitosan-based coatings with controlled properties for biomedical applications, ensuring enhanced patient outcomes and implant performance.

Stress shielding and osseointegration are two main challenges in bone regeneration, which have been targeted successfully by chemical and physical surface modification methods. Direct irradiation synthesis (DIS) is an energetic ion irradiation method that generates self‐organized nanopatterns conformal to the surface of materials with complex geometries (e.g., pores on a material surface). This work exposes porous titanium samples to energetic argon ions generating nanopatterning between and inside pores. The unique porous architected titanium (Ti) structure is achieved by mixing Ti powder with given amounts of spacer NaCl particles (vol % equal to 30%, 40%, 50%, 60%, and 70%), compacted and sintered, and combined with DIS to generate a porous Ti with bone‐like mechanical properties and hierarchical topography to enhance Ti osseointegration. The porosity percentages range between 25% and 30% using 30 vol % NaCl space‐holder (SH) volume percentages to porosity rates of 63%–68% with SH volume of 70 vol % NaCl. Stable and reproducible nanopatterning on the flat surface between pores, inside pits, and along the internal pore walls are achieved, for the first time on any porous biomaterial. Nanoscale features were observed in the form of nanowalls and nanopeaks of lengths between 100 and 500 nm, thicknesses of 35‐nm and heights between 100 and 200 nm on average. Bulk mechanical properties that mimic bone‐like structures were observed along with increased wettability (by reducing contact values). Nano features were cell biocompatible and enhanced in vitro pre‐osteoblast differentiation and mineralization. Higher alkaline phosphatase levels and increased calcium deposits were observed on irradiated 50 vol % NaCl samples at 7 and 14 days. After 24 h, nanopatterned porous samples decreased the number of attached macrophages and the formation of foreign body giant cells, confirming nanoscale tunability of M1–M2 immuno‐activation with enhanced osseointegration. [ABSTRACT FROM AUTHOR]

The objective of study is to determine the effective Young modulus before and after the completed osseointegration process using mathematical modelling of a titanium porous structure. A novel model is proposed in the form of 3D arrays of Gibson-Ashby cells with rigid clamping of horizontal beams resting on elastic foundation. Calculations made on the basis of the developed model are compared with known models and literature data. The assumption is proved that the osseointegration process due to the bone tissues ingrowth into the pores of titanium implant could affect the Young modulus increasing its value in proportion to porosity of a specimen.

Biomaterials are the basis for the development of medicine because they allow safe contact with a living organism. The aim of this work was to produce innovative oxide layers with a microporous structure on the surface of commercially pure titanium Grade 4 (CpTi G4) and to characterize their properties as drug carriers. The anodization of the CpTi G4 subjected to mechanical grinding and electrochemical polishing was carried out in a solution of 1M ethylene glycol with the addition of 40 g of ammonium fluoride at a voltage of 20 V for 2, 18, 24, and 48 h at room temperature. It was found that the longer the anodization time, the greater the number of pores formed on the CpTi G4 surface as revealed using the FE-SEM method, and the greater the surface roughness determined in profilometric tests. As the anodizing time increases, the amount of the drug in the form of gentamicin sulfate incorporated into the resulting pores decreases. The most favorable drug release kinetics profile determined via UV–VIS absorption spectroscopy was found for the CpTi G4 anodized for 2 h.

Artificial bone porous titanium materials are widely used in orthopedic implants. However, the traditional constitutive model is often limited by the complexity and accuracy of the model, and it is difficult to accurately and efficiently describe the constitutive relationship of porous titanium materials. In this study, structured data were established based on experimental data from published papers, and goodness of fit (R2), mean absolute error (MAE) and mean absolute percentage error (MAPE) were used to evaluate the model. The prediction effect of random forest (RF), multi-layer perceptron (MLPR) and support vector machine (SVR) on the constitutive relationship of porous titanium materials was discussed. Through comprehensive comparison, it can be seen that the RF model with max_depth of 24 and n_estimators of 160 has the best performance in prediction, and the average absolute percentage error is less than 4.4%, which means it can accurately predict the temperature sensitivity and strain rate sensitivity of porous titanium materials. And its predictive ability is better than that of the traditional constitutive model, which provides a new idea and method for the constitutive modeling of porous titanium materials.

The use of customized 3D-printed structures has been gaining popularity in non-union management, as it allows for bypassing the defect while promoting osseointegration. Additionally, porous titanium implants minimize stress shielding due to their stiffness and elastic modulus being closer to that of bone. The interconnected channels increase the surface area and provide space for cell adhesion and proliferation. This study presents the case of a 62-year-old female patient with concomitant knee osteoarthritis recalcitrant aseptic atrophic nonunion in the tibial proximal metaphysis. Due to the small distance between the nonunion site and the joint line, nonunion treatment had to be included in the treatment plan, as it would result in a lack of mechanical stability of the tibial component, and techniques such as plating were not an option. A customized 3D-printed porous titanium cone was used to bypass the fracture site and support the stem used with the CCK prosthesis, allowing for simultaneous nonunion and osteoarthritis management.

Propose: This study aimed to describe the design and surgical techniques of a three-dimensional (3D) printed strut-type prosthesis with a porous titanium surface for distal femur giant cell tumors of bone (GCTB) and evaluate the short-term clinical outcomes. Methods: From June 2018 to January 2021, 9 consecutive patients with grade I or II GCTB in the distal femur underwent extended intralesional curettage followed by 3D-printed strut-type prosthesis combined with autograft reconstruction were retrospectively reviewed to assess their clinical and radiographic outcomes. Results: All patients were followed up for 30.8 ± 7.5 months (18-42 months) after surgery. The mean affected subchondral bone percentage and the mean subchondral bone thickness before surgery was 31.8% ± 9.6% (range, 18.2% ~50.2%) and 2.2 ± 0.8 mm (range, 1.2-4.0 mm), respectively. At the final followup, all the patients were alive without local recurrence; no postoperative complications were observed. Patients had significant improvements in postoperative MSTS-93 score [(26.7 ± 2.4) vs. (18.8 ± 3.7), P < 0.05], and ROM [(122.8° ± 9.1°) vs. (108.3° ± 6.1°), P < 0.05] compared with their preoperative statuses. Furthermore, the mean subchondral bone thickness has increased to 10.9 ± 1.3 mm (range, 9.1-12.1 mm). Conclusion: 3D-printed strut-type prosthesis combined with autograft reconstruction provides acceptable early functional and radiographic outcomes in patients with grade I or II GCTB in distal femur due to the advantages of the prosthesis such as good biocompatibility, osseointegration capacity, and subchondral bone protection. If our early outcomes can be further validated in studies with more patients and sufficient follow-up, this method may be evaluated as an alternative for the treatment of grade I or II GCTB in the distal femur. [ABSTRACT FROM AUTHOR]

Medical porous titanium and titanium alloys have been used well in clinical applications.However,in order to accelerate good bone healing and osseointegration in vivo,it is necessary to modify the surface of porous titanium and titanium alloys.In this paper,the preparation methods of medical porous titanium and titanium alloys were briefly introduced,including powder metallurgy,metal deposition and casting.Then,two frequently-used surface modification methods for medical porous titanium and titanium alloys at home and abroad,namely,preparation of bioactive coatings and surface chemical modification,were mainly reviewed.

The design of the implant and osseointegration play an important role in the long-term stability of implants. This study aims to investigate the impact of porous implants on full and partial osseointegration in varying bone qualities. Finite element models of porous implants were modeled and assembled with normal and weak bones considering full and partial osseointegration. These assemblies were simulated under an occlusal load of 200 N when the outer surfaces of bones were fixed in all directions. The results showed that in the case of full osseointegration, the stresses in surrounding bones were increased with decreasing implant stiffness, while decreased in partial osseointegration. Moreover, the maximum octahedral shear strain in the weak bone exceeded 3000 µε in all the cases but decreased (from 7256 to 3632 µε) with decreasing implant stiffness. According to the mechanostat hypothesis, using porous implants in normal bone may enhance bone density in full osseointegration, while susceptivity of bone damage may reduce in weak bones using porous implants. Thus, careful selection of implant material and design based on the patient's specific bone quality is crucial for successful outcomes. [ABSTRACT FROM AUTHOR]

Cementless fixation in total knee arthroplasty (TKA) is re-emerging due to improvements in biomaterials, surgical technique, and implant design. Albeit rare, failure of osseointegration typically occurs within the first 2 years, and limited data exist on survivorship of the modern cementless TKA designs. This study evaluated clinical survivorship of 2 contemporary cementless TKA designs at minimum 2-year follow-up. A total of 627 cementless TKAs were performed up to July 2022. Three hundred thirty-nine cases were eligible for 2-year follow-up. Indications centered around bone quality and involved predominantly younger patients. The 2 designs consisted of tibial components with a highly porous titanium ingrowth surface, a central keel, and peripheral cruciform pegs with a porous cobalt-chromium femur. Survivorship estimates were calculated using right-censored non-parametric Kaplan–Meier methodologies. A total of 226 TKAs obtained minimum 2-year follow-up with a mean of 3.6 years (range, 2 to 10). The all-cause revision rate was 2.4% (8 of 339). The revision rate due to aseptic loosening was 0.6% (2 of 339) consisting of 2 femoral components. No tibial components were revised for aseptic loosening. Kaplan–Meier survivorship free from aseptic loosening was 99% (95% confidence interval 98 to 100) at a maximum of 10 years. These results demonstrate encouraging survivorship of cementless fixation in primary TKA with use of contemporary ingrowth biomaterials and modern implant designs. This particular tibial implant design with a highly porous titanium fixation surface, central keel, and peripheral cruciform pegs demonstrated excellent clinical survivorship without failure which may portend superior fixation. IV–case series, no control group/historical control group. [ABSTRACT FROM AUTHOR]

Porous materials are very efficient in absorbing mechanical energy, for instance, in combined armor, in order to improve the anti-ballistic protection characteristics. In the present study, porous titanium-based structures were manufactured via three different powder metallurgy methods using titanium hydride (TiH2) powder, which provided activated sintering, owing to dehydrogenation. The emission of hydrogen and shrinkage of powder particles on dehydrogenation also added an additional potential to control the sintering process and create desirable porosities. TiH2 powder was sintered with additions of NaCl or ammonium carbide as pore holding removable agents, while highly porous Ti-Al structures were formed via liquid phase reactive sintering of TiH2 and Al powders. The microstructures and porosities of sintered dehydrogenated titanium and Ti-Al structures were comparatively studied. Mechanical characteristics were evaluated using compression testing with strain rates varying from quasi-static to high levels. The resonant frequency method was also employed to determine damping parameters and elastic modulus of these materials. All testing methods were aimed at characterizing the energy-absorbing ability of the obtained porous structures. The desired strength, plasticity and energy-absorbing characteristics of porous titanium-based structures were assessed, and the possibilities of their application were also discussed. Based on the obtained results, it was found that porous titanium materials produced with the use of ammonium carbonate showed promising energy absorption properties. [ABSTRACT FROM AUTHOR]

Tri-calcium-phosphate Ca3(PO4)2 is considered a promising material to improve implant and bone tissue linking. Titanium (Ti), a highly porous material, was coated with crystalline brushite using an electrochemical process so that it could be used as an implant material. The aim of this research is to get a faster ingrowth of bone-tissue inside the porous structure. The crystalline coating was characterized by the standard XRD and SEM techniques. Additionally, the phase evolution of Ca3(PO4)2-crystals with different kinds of sterilization techniques was observed. In-vitro tests on the biocompatibility of the coating were done with human mesenchymal stem cells (HMSCs). The HMSCs are the most promising cell type for regenerative medicine and tissue engineering owing to their ability to differentiate into several tissues, such as, bone, cartilage, tendon, and muscle. For the treatment of local bone defects expanded HMSCs could be loaded on Ca3(PO4)2 coated metallic matrices and delivered to the target site. A possible application is brushite-coated porous titanium as a carrier matrix. To determine whether cell functions of HMSCs are influenced by the brushite surface, HMSCs were cultured on brushite-coated and uncoated porous titanium specimens. The viability and proliferation of HMSCs were successfully analyzed. Additionally, the release of cytokines (IL-6, IL-8, IL-11) were quantified as a marker of cell activation. The viable cells could be detected on specimens after 48 h initial seeding. After 8 days cell number on both specimens increased, although the proliferation on brushite-coated titanium was decreased compared to the uncoated surfaces. The release of both, IL-8 and IL-11 increased significantly due to the cultivation of HMSCs on the coated specimens for 8 days.

Introduction: Porous dental implants represent a promising strategy to reduce failure rate by favoring osseointegration or delivering drugs locally. Incorporating porous features weakens the mechanical capacity of an implant, but sufficient fatigue strength must be ensured as regulated in the ISO 14801 standard. Experimental fatigue testing is a costly and time-intensive part of the implant development process that could be accelerated with validated computer simulations. This study aimed at developing, calibrating, and validating a numerical workflow to predict fatigue strength on six porous configurations of a simplified implant geometry.Methods: Mechanical testing was performed on 3D-printed titanium samples to establish a direct link between endurance limit (i.e., infinite fatigue life) and monotonic load to failure, and a finite element model was developed and calibrated to predict the latter. The tool was then validated by predicting the fatigue life of a given porous configuration.Results: The normalized endurance limit (10% of the ultimate load) was the same for all six porous designs, indicating that monotonic testing was a good surrogate for endurance limit. The geometry input of the simulations influenced greatly their accuracy. Utilizing the as-designed model resulted in the highest prediction error (23%) and low correlation between the estimated and experimental loads to failure (R2 = 0.65). The prediction error was smaller when utilizing specimen geometry based on micro computed tomography scans (14%) or design models adjusted to match the printed porosity (8%).Discussion: The validated numerical workflow presented in this study could therefore be used to quantitatively predict the fatigue life of a porous implant, provided that the effect of manufacturing on implant geometry is accounted for.

Ultra high molecular weight polyethylene (UHMWPE), a common material for artificial joint linings, lacks appropriate bioactivity and antibacterial property, which could lead to prosthetic loosening and infections after surgery. Herein, a biofunctionalized UHMWPE material was developed by constructing a firmly bonded porous titanium layer on UHMWPE surface through hot-pressing. The micron-scale titanium surface was then activated by tannic acid treatment, and co-immobilized with Bone Morphogenetic Protein-2 and vancomycin. Scanning electron microscopy, mechanical testing, contact angle measurement, X-ray photoelectron spectroscopy analysis, and infrared spectrometry confirmed the successful construction of the coatings on UHMWPE without causing obvious oxidative degradation. The biofunctionalized UHMWPE surface significantly promoted cell adhesion and proliferation, and inhibited bacterial formation in vitro and in vivo. A preliminary in vivo study of canine hip replacement showed that the UHMWPE acetabular cup with the coating had good biocompatibility and promoted new bone formation and integration. These findings support the use of biofunctionalized UHMWPE as promising materials for artificial joint prostheses.

A gelatin-based hydrogel was infiltrated and degraded-released in two different titanium foams with porosities of 30 and 60 vol.% (Ti30 and Ti60 foams) and fabricated by the space holder technique to evaluate its potential to act as an innovative, alternative, and localised method to introduce both active pharmaceutical ingredients, such as antibiotics and non-steroidal anti-inflammatory drugs, and growth factors, such as morphogens, required after bone-tissue replacement surgeries. In addition, the kinetic behaviour was studied for both infiltration and degradation-release processes. A higher infiltration rate was observed in the Ti60 foam. The maximum infiltration hydrogel was achieved for the Ti30 and Ti60 foams after 120 min and 75 min, respectively. Further, both processes followed a Lucas-Washburn theoretical behaviour, typical for the infiltration of a fluid by capillarity in porous channels. Regarding the subsequent degradation-release process, both systems showed similar exponential degradation performance, with the full release from Ti60 foam (80 min), versus 45 min for Ti30, due to the greater interconnected porosity open to the surface of the Ti60 foam in comparison with the Ti30 foam. In addition, the optimal biocompatibility of the hydrogel was confirmed, with the total absence of cytotoxicity and the promotion of cell growth in the fibroblast cells evaluated. [ABSTRACT FROM AUTHOR]

Based on the modern methods of SEM, voltammetry, and gravimetric analysis, samples of current collectors used in electrolyzers with a solid polymer electrolyte, made of porous titanium with various degrees of etching in concentrated hydrochloric acid, were studied. A gravimetric study of the etching process of samples of various sizes from porous titanium showed that throughout the process there is a loss of mass of the sample, with the exception of two short intervals, presumably due to the formation of hydrides (60-80 sec) and oxides (4-5 min), and the samples of smaller volumes were more sensitive to weight loss and weight growth. The use of the SEM method made it possible to reveal that etching over different time intervals changes the structure of porous titanium, reducing the average particle size and increasing their porosity .In this case, the surface inhomogeneity increases due to the formation of cavities in titanium and deterioration of the contact of the current collector surface with the catalytic layer. The consequence of this is the difference in the current-voltage characteristics of electrolysis cells with different duration of etching of the current collectors: there is a decrease in the productivity of electrolysis with an increase in the duration of etching of the current collectors by ~8% for etching more than 1 minute and ~18% for etching more than 4 minutes as compared to the simultaneous immersion of the sample in acid to clean the surface. [ABSTRACT FROM AUTHOR]

BACKGROUND: Increases in the numbers of surgical procedures for primary total hip arthroplasty (THA) inevitably lead to increases in the requirements for revision THA. The achievement of long-term stability is difficult or impossible by conventional implants in patients with severe destruction of the acetabulum. OBJECTIVE: This case report presents a successful treatment using a specific three-dimensional (3D)-printed porous titanium acetabular composite component without a flange in the management of Paprosky type IIIB acetabular defects. METHOD: A 65-year-old female diagnosed with right hip prosthetic loosening with a huge acetabular defect presented to our hospital. We designed the 3D model of the pelvis and created an individualized 3D-printed porous titanium acetabular composite component for revision THA. The procedure was performed through a posterolateral approach, and the component was implanted in the defect and fixed with cup screws using the drill guides. RESULTS: At the last follow-up at 2 years, the patient had a satisfactory hip joint function and no signs of loosening or other complications were found. CONCLUSIONS: The 3D-printed porous titanium acetabular composite component without a flange is showing promising clinical and radiological outcomes in the management of Paprosky type III acetabular defects. [ABSTRACT FROM AUTHOR]

The objective of study is to determine the effective Young’s modulus of open cell porous titanium based on the Gibson – Ashby model. Two novel models are proposed in the form of 3D Gibson – Ashby cell arrays with two variants for connecting vertical and horizontal beams – hinged support and rigid clamping. Calculations made on the basis of the developed models are compared with results of known models and literature data. It is proved the assumption that at high porosity, the deformation of samples occurs to a greater extent due to the deflection of horizontal beams, and with a decrease in porosity, the compressive deformation of vertical beams is playing an important role.

Porous titanium is an excellent bone-implant biomaterial. This article uses SiC as a reinforcing agent to compound into porous titanium materials to improve the mechanical properties of porous titanium as medical materials. Porous titanium with different SiC(0–7.5wt.%) content was prepared by the conventional powder metallurgy method. Results revealed that SiC significantly improves porous titanium's densification and sintering properties. Moreover, when the SiC content is 3wt.%, the compressive capacity of porous titanium reaches 191.1Mpa. Likewise, the addition of SiC significantly improves the hardness and strength.

Bioactivity and stress shielding are the most important problems of medical implanted porous titanium. In this study, porous titanium with 40% porosity was prepared by one-step spark plasma sintered (SPS) technology, and the surface of porous titanium was modified by a simplified alkali treatment method. The effects of a high concentration on pore properties, mechanical properties, and biological activities of porous titanium were investigated. The results show that the surface of porous titanium treated with a high concentration of alkali forms an interconnected network layer, which provides nucleation points for the formation of apatite. Porous titanium can still meet the requirements of hard tissue replacement after treatment with high-concentration alkali solution (yield strength (130 MPa) and elastic modulus (6.0 GPa)). A layer of apatite is formed on the surface of porous titanium after alkali treatment. The ability of inducing apatite formation increases with the increase of lye concentration. In addition, the results of proliferation and live dead cell staining of bone mesenchymal stem cells (BMSC) showed that alkali treatment had no toxic effect on the cells. With the increase of concentration, the cell activity was significantly enhanced. Therefore, the bioactive porous titanium modified with simplified alkali has a good medical prospect as artificial bone material. [ABSTRACT FROM AUTHOR]

This study produced porous titanium by partial sintering using the spark plasma sintering (SPS) processing method. The sintering temperature used varied between 600 and 800 °C. In addition, porous titanium prepared by conventional powder metallurgy under Argon atmosphere was studied for comparison. The results showed that porous titanium had a porosity value ranging from 4.2 to 27.5%. A sintering temperature of 600–800 °C in the SPS would reduce the elastic modulus of titanium (13.6–24.4 GPa) to fit the elastic modulus of human bone (4–30 GPa). However, the in vitro studies showed that the porous titanium prepared by SPS at 600 °C, despite having preferred porosity, would have less cell viability compared to the porous titanium prepared by conventional powder metallurgy. Therefore, the oxidation and the densification process have more effect on biocompatibility since they correlate to the dissolution of titanium ions into the cell. [ABSTRACT FROM AUTHOR]

Porous titanium based implants have found various use in dental implants, tissue and bone regeneration. In the present paper, a method of generating models of porous titanium material has been developed from micro-computed tomography radiograph images. Images are processed and three solid models are generated for analysis. To observe the stress contour and the failure initiation at micro level, a method of submodeling has been employed to investigate the effect of loading on the micro-computed tomography based models kept at the centre of a global model of near equivalent porosity. Equivalent, shear and normal stress profiles on the generated model have been analysed to quantify the variation of stress-strain nature and to predict the nature of failure at the micro-porous localized regions due to cyclic nature of loading. Additionally, the average wall shear stress of one of the scaffolds has been determined using Computational Fluid Dynamics analysis at three different inlet velocities. [ABSTRACT FROM AUTHOR]

Background Context: 3D-printed titanium cage designs can incorporate complex, porous features for bone ingrowth and a greater surface area for minimizing subsidence. In a companion study (Part 1), we determined that increased surface area leads to decreased subsidence; however, it remains unclear how increasing the cage surface area, resulting in a smaller graft aperture, influences fusion., Purpose: We evaluated the effects of surface area of 3D-printed titanium cages and the use of autologous bone grafts on spinal fusion in sheep., Study Design: In vivo large animal study in 12 sheep., Methods: Interbody fusion was performed in 12 adult sheep at 24 levels (L2-3 and L4-5) using 3D-printed titanium cages with bilateral pedicle screw fixation. The cage designs varied in aperture: standard (low endplate surface area), small (medium endplate surface area), or none (high endplate surface area). These cages were packed with autologous iliac crest bone grafts (ICBG). A fourth group was implanted without bone grafts, using the no-aperture cage. Fusion was evaluated at 16 weeks via manual palpation, microcomputed tomography (microCT), histology, and histomorphometry., Results: Standard, small, and no-aperture cages packed with ICBG resulted in high fusion rates (80%, 100%, and 83%, respectively) at 16 weeks by manual palpation, and these results were not significantly different. Implantation without ICBG was associated with a significantly lower fusion rate (33%, p<0.05). Histological, histomorphometry, and microCT results supported the findings obtained by manual palpation; findings from these modalities showed new bone spanning the vertebral endplates in the spines graded as fused by manual palpation., Conclusions: Similar fusion results for standard, small, and no-aperture cage designs packed with ICBG suggest that aperture size does not influence fusion results in the sheep model. However, without ICBG grafting, fusion was significantly decreased, suggesting that graft material is necessary to predictably obtain fusion in this model. When the in vitro subsidence data (companion study, Part 1) is considered with the in vivo fusion data described here, porous 3D-printed titanium cages with maximal surface endplate contact and bone grafting perform favorably, resulting in low subsidence and high fusion rates., Clinical Significance: 3D-printed porous titanium interbody cages are novel devices with increasing clinical use. The study results show that the aperture size of the interbody cage did not influence fusion in a large animal (sheep) model. The use of bone graft material was the most important variable affecting fusion. These data suggest that the clinical use of 3D Ti cages without graft material should be avoided., (Copyright © 2024. Published by Elsevier Inc.)

Introduction: The assessment of segmental fusion after Lateral Lumbar Interbody fusion (LLIF) using 3D-printed porous titanium cage is still not well studied. Various criteria, such as the presence of bone bridges (BB) between adjacent vertebrae, serve as indicators for anterior fusion. However, limited radiological studies have investigated zygapophyseal joints (ZJ) status following LLIF with porous titanium cages vs. conventional titanium threaded cages. The porous design of the latest titanium intervertebral cages is thought to enhance the bone-to-implant fusion rate. This radiological study aimed to compare the fusion patterns post-LLIF using 3D-printed porous titanium cages against those using threaded titanium cages. This radiological study aimed to compare the fusion patterns after LLIF using 3D-printed porous titanium cages against those using threaded titanium cages., Material and Methods: This retrospective, single-center radiological study involved 135 patients who underwent LLIF and posterior percutaneous screw fixation for degenerative spondylolisthesis. The study included 51 patients (Group A) with the novel porous titanium cages and 84 patients (Group B) with conventional threaded titanium cages. Inclusion criteria mandated complete radiological data and a minimum follow-up period of 24 months. The study evaluated intervertebral bone bridges (BB) for anterior fusion and zygapophyseal joints (ZJ) ankylotic degeneration, based on Pathria et al., as evidence of posterior fusion and segmental immobilization., Results: Two years after surgery, intervertebral BB were identified in 83 segments (94.31%) in Group A and in 87 segments (88.77%) in Group B. ZJ Pathria grade I was observed in 2 segments (2.27%) of Group A and in 4 segments (4.08%) of Group B. Grade II was seen in 5 segments (5.68%) of Group A and in 6 segments (6.12%) of Group B. Posterior fusion, classified as grade III, was found in 81 segments (92.04%) of Group A and 88 segments (89.79%) of Group B. Subsidence incidence was 5.88% (3 segments) for the novel cage and 9.88% (8 segments) for the conventional cage., Conclusions: The architecture of porous titanium cages offers a promising solution for increasing bone ingrowth and bridging space, supporting successful spinal fusion while minimizing the risk of subsidence., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Velluto, Mundis, Scaramuzzo, Perna, Capece, Cruciani, Inverso, Borruto and Proietti.)

Objective. To conduct a comparative retrospective analysis of the anatomical and functional results of surgical treatment of proximal humerus fractures AO/OTA 11-B, 11-C using different methods in patients over 50 years old with osteoporosis to justify a differential approach. Methods. The study included 102 patients aged 50 years and older with osteoporosis and proximal humerus fractures AO/OTA 11-B, 11-C. The patients were divided into three groups: I -- 50 (16 men, 34 women) whom were performed open reduction and internal fixation (ORIF) with the PHILOS plate; II -- 44 (8 men, 36 women) -- ORIF with the PHILOS plate and using 3D polylactide (PLA) porous implants were applied; III -- 8 (2 men, 6 women) whom were performed primary reversed total shoulder arthroplasty (RTSA) with developed total reversible endoprosthesis. The results of treatment were evaluated according to the Constant- Murley Shoulder Score system after 3, 6, 12 months. The results. Positive results in the first group were obtained in 72.0 % of patients (the average Constant-Murley Shoulder Score after 12 months was 78.4 points); in the second -- in 81.8 % (88.0 points); in the third -- 75.0 % (82.0 points). A differentiated approach to the choice of surgical treatment of patients aged 50 years and older with fractures AO/OTA 11-B, 11-C is proposed. The clinical trial of the reverse total modular shoulder endoprosthesis developed by us using porous 3D titanium parts, manufactured by additive technologies, showed positive short-term results. The design features of the device increase the reliability and durability of proposed endoprosthesis. Conclusions. RTSA in the case of unstable proximal humerus fracture or in the case of metal structure migration after primary ORIF in patients with low bone mineral density is the effective surgical intervention that allows to achieve satisfactory functional results in up to 3 years. [ABSTRACT FROM AUTHOR]

Lightweight porous metals have been focused on as structural and energy absorbing materials. Mechanical properties of classical porous metals fall under the specific specimen dimension. Such cell size effects are mainly caused by the disordered cells. The present study experimentally evaluates the cell size effects of additively manufactured porous metals consisting of ordered cells. Different sized porous titanium specimens consisting of ordered rhombic dodecahedron cells are manufactured through electron beam melting process. Mechanical properties are determined by quasi-static compression tests. The plateau stress and the energy absorption are almost independent of the specimen dimension divided by the cell diameter. Experimental results conclude that the cell size effects are suppressed in additively manufactured porous metals consisting of well-defined ordered cells. [ABSTRACT FROM AUTHOR]