Search Results (1,359)

Articular cartilage defects affect millions of patients annually and pose one of the most persistent challenges in orthopedic surgery, owing to the tissue’s inherent avascular and alymphatic nature. Current surgical approaches, microfracture, autologous chondrocyte implantation (ACI/MACI), and osteochondral grafting, share a common failure mode: inadequate adhesion between repair constructs and surrounding native cartilage, contributing to deterioration rates of 15–75% at five-year follow-up across all techniques. This review repositions adhesion not as a supplementary material property but as the central determinant of clinical success in cartilage repair. We systematically evaluate the biomechanical demands imposed by the joint environment and define clinically relevant adhesion thresholds. Adhesive hydrogel strategies are categorized by surgical context: microfracture augmentation, ACI/MACI enhancement, osteochondral graft integration, and standalone repair platforms. Material platforms are analyzed across catechol/dopamine systems, NHS ester chemistry, photocrosslinkable hydrogels, supramolecular approaches, and multi-mechanism hybrids. Injectable formulations for arthroscopic delivery are critically examined alongside key translational barriers, including fatigue durability, biocompatibility–adhesion trade-offs, sterilization compatibility, batch variability, and regulatory classification ambiguity. Future directions encompass 4D bioprinting, AI-guided formulation optimization, and stimuli-responsive reversible adhesion systems. Adhesive hydrogels represent the missing link that current cartilage repair paradigms require. Full article

Interbody fusion cages are widely used to restore spinal stability, yet conventional designs often exhibit mechanical mismatch and limited biological integration. Functionally graded spinal cages incorporate spatial variations in composition and structure to better align mechanical properties with the surrounding bone environment. Although these designs have been extensively studied from an engineering perspective, their biological implications remain less clearly defined. This review examines how graded material composition, surface characteristics, porosity, and lattice architecture are associated with cellular and molecular responses relevant to bone regeneration. Reported biological responses include protein adsorption, immune modulation, angiogenesis, and osteogenic differentiation. Evidence from orthopaedic implants and tissue engineering systems suggests that such design features may influence mechanobiological pathways; however, direct experimental validation in spinal applications remains limited. Previous reviews primarily focus on material properties or mechanical performance of functionally graded spinal cages. This review presents a structured design-to-biology perspective linking graded implant features with biological responses relevant to spinal fusion. By integrating findings across biomaterials, mechanobiology, and implant design, this review presents a structured design-to-biology perspective and highlights current evidence, translational limitations, and key knowledge gaps in the field. Functionally graded spinal cages represent a promising but still evolving strategy, and further spine-specific mechanobiological and clinical studies are required to establish their impact on fusion outcomes. Full article

Background: Current murine glioblastoma (GBM) models do not incorporate tumor resection and thus do not allow study of recurrent GBM after surgery, including postsurgical changes in the tumor microenvironment (TME), thereby limiting translational relevance. Methods: In phase 1 of a three-phase study, we compared tumor cell implantation into a cavity created using conventional microdissection techniques or the Myriad Research Laboratory System (MRLS) versus direct implantation into the brain without a cavity, and assessed morbidity using the neurological severity score (NSS). In phase 2, we developed a new surgical resection model, the Surgical murine GBM resection model (Sur-rGBM), and examined the effects of tumor resection on the tumor microenvironment (TME) and on overall survival. In phase 3, we compared the therapeutic response to temozolomide (TMZ) with or without anti-VEGF antibody, after resection (Sur-rGBM) or no resection. Tumor growth was confirmed before and after resection by ultrasound. Animals were euthanized for immunohistochemical assessment at maximal tumor growth. Results: Creating a cavity for tumor cell implantation using MRLS improved survival compared to direct cell injection with no cavity. Tumor resection increased survival, and TMZ combined with an anti-VEGF antibody after tumor resection improved survival compared with surgery or TMZ alone. Resection induced significant changes in biomarker expression within the TME. Conclusions: Our novel murine GBM surgical resection model (Sur-rGBM) provides reliable, controlled tumor growth and a standardized resection technique to facilitate studies on TME changes and therapeutic response after tumor resection. Full article

Background/Objectives: Rami fractures in anteroposterior compression (APC)-type pelvic ring injuries show favorable outcomes with conservative management in isolated settings; however, the necessity of direct rami fixation when posterior instability is present remains unclear. This study aimed to determine whether adding direct rami fixation to symphyseal plating improves clinical and radiologic outcomes in APC-type pelvic ring injuries. Methods: This retrospective cohort study included a final cohort of 98 patients with APC type II or III pelvic ring injuries and concomitant pubic rami fractures treated at a Level 1 trauma center (2014–2022). All patients underwent plate-based symphyseal fixation, classified into four groups by fixation strategy. Primary outcomes were rami nonunion and implant-related complications, analyzed with parsimonious multivariate logistic regression (events-per-variable ratio ≥ 10). Results: Among 98 patients (mean age 45.4 ± 16.2 years; 76.5% male), complete posterior ring injury was independently associated with rami nonunion (aOR 8.176; 95% CI 2.448–27.309; p = 0.001), implant-related complications (aOR 3.364; 95% CI 1.250–9.049; p = 0.016), and overall complications (aOR 4.292; 95% CI 1.640–11.233; p = 0.003). Female sex was an additional independent predictor of overall complications (aOR 4.226; 95% CI 1.443–12.378; p = 0.009). Direct rami fixation was not a significant predictor of any outcome but consistently increased operative time in pairwise subgroup comparisons (Group 1 vs. 2: 64.9 vs. 106.9 min, p < 0.001; Group 3 vs. 4: 95.1 vs. 153.5 min, p < 0.001). Pairwise subgroup comparisons were severely underpowered (power range 5–16%); therefore, the absence of statistically significant differences between fixation strategies should not be interpreted as evidence of equivalence. Because more complex fractures were more likely to receive additional fixation, confounding by indication further limits these comparisons. Conclusions: Complete posterior ring injury was the dominant predictor of adverse outcomes in APC-type pelvic ring injuries. In this underpowered exploratory analysis, adding direct rami fixation to symphyseal plating did not demonstrate a statistically significant reduction in complications but was associated with longer operative time. Direct rami fixation may be reserved for selected cases with marked displacement, poor indirect reduction, or compromised bone quality; larger prospective studies are needed before firm recommendations can be made. Full article

Millions of persons worldwide experience varying degrees of hearing loss, traditionally addressed through prosthetic solutions such as hearing aids and cochlear implants. However, a significant proportion of individuals cannot benefit from these technologies, cannot access them, or choose not to use them. In this context, non-prosthetic assistive technologies have emerged as a complementary paradigm, leveraging advances in sensing, artificial intelligence, and wearable computing to transform acoustic information into alternative perceptual representations rather than restoring auditory function. This survey provides a review of such systems, focusing on technologies that enhance environmental awareness, communication, and social interaction. Existing approaches are categorized along two main dimensions: the tasks they perform and the platforms on which they operate. Task-oriented analysis includes sound recognition (speech and non-speech), sound source localization, emotion recognition, sign language recognition, and related emerging functionalities. Platform-based analysis emphasizes wearable devices and mobile solutions enabling real-time and context-aware assistance. The survey further highlights key research trends, including real-time auditory scene analysis, portable processing, and artificial intelligence. It shows that recent studies increasingly demonstrate that combining auditory, visual, and haptic modalities improves robustness and usability in real-world conditions, particularly in noisy and dynamic environments. Finally, open challenges such as energy efficiency, latency, evaluation methodologies, and user acceptance are discussed. By synthesizing existing work and identifying open research directions, this survey aims to provide a structured foundation for future developments in intelligent, non-prosthetic assistive systems that redefine how auditory information is accessed and interpreted. Full article

Patient-matched implants (PMIs) enable precise anatomical reconstruction but often introduce unforeseen intraoperative challenges that can provoke stress, reduce frustration tolerance, and influence surgical decision-making. Despite the growing clinical use of PMIs, the behavioural and psychological dimensions underpinning these challenging surgeries remain underexplored. This study examined the relationship between surgeon temperament, specifically frustration tolerance threshold, patience, and adherence to planned surgical workflows during PMI procedures. A qualitative thematic study was conducted over 22 months across two academic centres and 86 private surgical practices in South Africa. Data were collected through semi-structured interviews with consultant surgeons, assistant surgeons, surgical technologists, and biomedical engineers, supplemented by direct observation and detailed field notes. Inductive content analysis, thematic coding, and descriptive quantitative trends derived from Likert-style questionnaires were used to identify behavioural patterns associated with intraoperative stress and workflow deviation. Participant reports indicated that low frustration tolerance, often expressed as impatience, was perceived to be linked to increased deviations from surgical plans, including implant modification (reported in 4.6% of the 86 practices), even when design and fit were optimal. In 2.3% of the 86 practices surveyed, surgical team members reported incidents where impatience was perceived to have compromised patient safety. Stress inoculation theory and emotional intelligence frameworks offered explanatory models for the observed behaviours. Within the limits of this exploratory qualitative study, surgeon temperament—particularly mental preparedness and frustration tolerance—emerged as a recurring theme associated with intraoperative PMI workflow adherence. Whether these factors are determinants of workflow adherence whilst using high-fidelity PMIs, or merely correlated with other unmeasured variables, remains to be tested in future quantitative research. Full article

To address issues such as thermal stress concentration in metal bone implants produced via high-energy beam direct additive manufacturing, a method was proposed to fabricate porous titanium scaffolds. This approach combined Fused Deposition Modeling (FDM) with a debinding–sintering process. Ti/ABS composite filaments with titanium volume fractions of 35%, 40%, and 45% were successfully developed via a single-screw extrusion process. Their feasibility in the FDM process was subsequently verified. The effects of different processing parameters on the forming quality and dimensional accuracy of the green bodies were investigated. After debinding and sintering the composite scaffolds prepared with optimized parameters, structurally intact porous titanium scaffolds were obtained. Microscopic characterization shows that the scaffold surface consists primarily of titanium, and the pore structure remains intact. Furthermore, compression tests were performed on three types of porous titanium scaffolds with different porosities. The results indicate that the combination of ABS/titanium alloy composite filaments, FDM technology, and debinding–sintering post-processing enables the high-quality and efficient production of porous titanium scaffolds. The elastic modulus of the resulting scaffolds ranges from 1.2 to 1.6 GPa, and the compressive strength is between 25.7 and 68.3 MPa. The elastic modulus matches that of human cancellous bone. Meanwhile, the compressive strength is significantly higher than that of cancellous bone and falls between the values for cancellous and cortical bone. These mechanical properties meet the requirements for human bone, providing a new approach for the manufacture of orthopedic implants. Full article

Dental implants are widely used to replace missing teeth, but peri-implantitis remains a major biological complication associated with bacterial biofilm formation on implant surfaces. The increasing incidence of peri-implant infections underscores the need for alternative antimicrobial strategies that effectively decontaminate complex titanium implant surfaces. This study evaluated the inhibitory effect of low-temperature microwave argon plasma on bacteria in an experimental model simulating peri-implant conditions and compared the responses of microorganisms with different biological characteristics. A 3D-printed mandibular bone segment model with an inserted Straumann BLX Roxolid^® dental implant was used to reproduce the peri-implant environment. Bacterial suspensions of Streptococcus mutans NBIMCC 1786 and the extremophilic bacterium Chromohalobacter canadensis NBIMCC 9077 have been exposed to a microwave non-equilibrium argon plasma jet (2.45 GHz, atmospheric pressure) for 1–7 min. Optical density measurements and colony growth analysis were used to assess antimicrobial effects. Plasma treatment induced a pronounced reduction in bacterial growth during the early post-treatment period. In C. canadensis, growth inhibition reached a plateau (~47–55% at 24 h) regardless of exposure time. In contrast, S. mutans showed a nonlinear response, with stable inhibition after short exposures (1–3 min) and partial recovery after longer treatments (5–7 min). These findings indicate that microwave argon plasma exhibits significant antimicrobial activity under controlled in vitro conditions, although its effectiveness depends on microorganism-specific biological characteristics. Because the present model was based on simplified single-species systems, direct clinical extrapolation remains limited and should be addressed in future studies using polymicrobial peri-implant biofilm models. Full article

Poly(lactic-co-glycolic acid) (PLGA) is one of the most extensively investigated biodegradable polymers for biomedical applications, owing to its tunable degradation kinetics, established biocompatibility, and regulatory approval. In implantology, PLGA-based systems have emerged as versatile platforms for scaffolds, coatings, and localized drug delivery, aimed at enhancing osseointegration and tissue regeneration. This review provides a focused and up-to-date analysis of PLGA applications in dental and orthopedic implantology, with particular emphasis on advances reported over the past decade. Unlike previous reviews that predominantly address general drug delivery or broad tissue engineering applications, this work establishes a direct correlation between polymer composition (LA:GA ratio), processing strategies, and biological outcomes, including degradation behavior, mechanical performance, and host response. Special attention is given to multifunctional PLGA systems incorporating antibiotics, growth factors, and bioactive nanoparticles, highlighting their role in improving antibacterial efficacy and osteogenesis. Emerging technologies such as nanostructured composites, additive manufacturing, and stimuli-responsive delivery platforms are critically evaluated. Key limitations—including acidic degradation by-products, burst release kinetics, and translational barriers—are discussed in the context of clinical applicability. By integrating physicochemical design with biological performance and recent clinical trends (2024–2025), this review proposes a framework for the rational development of next-generation PLGA-based implant systems. Full article

Bone is a hierarchically organized composite material with unique mechanical properties and an intrinsic regenerative capacity that conventional repair strategies, including autografts, allografts, xenografts, and metallic or ceramic implants, fail to fully replicate due to donor scarcity, immunogenicity, mechanical mismatch, and poor long-term integration. Bone tissue engineering (TE) offers a biologically informed alternative by integrating osteoconductive scaffolds, osteogenic progenitor cells, and osteoinductive signaling molecules into a unified regenerative framework. Unlike existing reviews that evaluate these components in isolation, this review provides a mechanistically integrated analysis that repositions scaffold design as a biologically instructive platform whose topography, stiffness, porosity, and surface chemistry collectively govern cell adhesion, mechanotransduction, osteogenic differentiation, and extracellular matrix remodeling. Critically, it moves beyond cataloging materials and fabrication approaches to evaluate how specific scaffold features drive biological outcomes and to identify frequently understated limitations, including polymer-ceramic degradation kinetics and the inadequacy of small-animal models for clinical translation. By synthesizing advances in biomaterials, additive manufacturing, and smart scaffold technologies within this integrative framework, this review provides researchers and clinicians with a structured framework for evaluating emerging strategies and prioritizing future directions in functional bone regeneration. Full article

Inter-implant distance (IID) is crucial for peri-implant bone preservation and long-term implant success. Traditionally, a minimum IID of 3 mm is recommended to limit marginal bone loss, although the biomechanical effect of smaller distances remains debated and may depend on multiple biological, prosthetic, and surgical factors. This study uses finite element analysis (FEA) to evaluate the effect of IID on stress distribution in peri-implant bones of D3 and D4 quality, considering crestal versus subcrestal implant placement, and interpreting results within Frost’s mechanostat theory. Implants with an internal conometric connection were modeled within simulated D3 and D4 mandibular bone blocks. IID values of 3 mm, 1.5 mm, and 1 mm were analyzed under masticatory load. Von Mises stresses in cortical and trabecular bone were compared against biomechanical thresholds (2 MPa disuse and 20 MPa remodeling limit). Results: Cortical stress increased with decreasing IID, more pronounced in crestal placement. In D3 bone, maximum cortical stress rose from 7.2 MPa (3 mm IID) to 16.5 MPa (1 mm IID) under crestal placement, while remaining within the mechanostat-based thresholds adopted in the present stress-interpretation framework. In D4 bone, cortical stress approached 20 MPa at 1 mm IID under crestal placement, indicating a less favorable mechanical condition within the interpretive framework adopted. Subcrestal placement reduced cortical stresses in both bone qualities. Trabecular stress remained stable in D3 (~1.7–8 MPa) and increased moderately in D4 (~up to 13 MPa). Conclusions: Within the limitations of this preclinical finite element study, decreasing inter-implant distance was associated with increased cortical stress, while subcrestal placement was associated with lower cortical stress than crestal placement. These findings should be interpreted only as comparative computational results, and no direct clinical conclusion can be drawn regarding the acceptability of a 1 mm inter-implant distance. Full article

Background/Objectives: Toric intraocular lens (IOL) implantation is the standard approach for correcting corneal astigmatism during cataract surgery and refractive lens exchange (RLE). Evidence on outcomes in eyes with high corneal astigmatism (≥2.00 diopters, D), particularly in heterogeneous real-world settings, remains limited. This study evaluated visual, refractive, and astigmatic vector outcomes of toric IOL implantation in a consecutive high-astigmatism cohort and investigated predictors of residual astigmatic error. Methods: This single-center, single-surgeon retrospective analysis of prospectively collected data included 161 eyes (118 patients) with preoperative corneal astigmatism ≥ 2.00 D undergoing cataract surgery or RLE with toric IOL implantation (June 2023–December 2025). Primary outcomes at one month included visual acuity, manifest refraction, and Alpins vector analysis at the corneal plane. Secondary analyses comprised refractive stability assessment (n = 75 eyes, median seven months), comparison of astigmatic outcomes between emmetropia-targeted and intentional myopia-targeted eyes, and multivariate regression of predictors of residual astigmatic error. Results: Mean postoperative UDVA and CDVA were 0.19 ± 0.24 and 0.09 ± 0.15 logMAR, respectively. Spherical equivalent prediction error was −0.19 ± 0.42 D (69.6% within ±0.50 D of target). Mean residual cylinder was 0.52 ± 0.49 D; 62% and 88.8% of eyes achieved ≤0.50 D and ≤1.00 D, respectively. Vector analysis demonstrated a mean difference vector of 0.53 ± 0.44 D, a correction index of 1.04 ± 0.20, and near-zero centroid deviation (0.03 D @ 43°), indicating the absence of systematic directional prediction error. Refractive outcomes were stable at medium-term follow-up. Astigmatic correction accuracy was equivalent between emmetropia-targeted and intentional myopia-targeted eyes (p > 0.05 for all primary metrics). Multivariate regression identified IOL cylinder power (β = 0.051, p = 0.031) and oblique astigmatism orientation (β = 0.299 vs. WTR, p = 0.032) as independent predictors of greater residual astigmatic error. No sight-threatening complications occurred. Conclusions: Toric IOL implantation provides safe, predictable, and stable correction of high corneal astigmatism in a real-world mixed cohort. Astigmatic accuracy is maintained regardless of intended spherical refractive strategy, supporting the use of toric IOLs in highly myopic patients targeted for residual myopia. Oblique astigmatism orientation is an independent predictor of reduced correction accuracy, consistent with known limitations of current toric calculators for this meridian. Full article

In the world of electronics, sensors are more than just components—they are the eyes, ears, and touchpoints of modern technology. From self-driving cars that rely on LiDAR and ultrasonic sensors to navigate complex environments, smart watches that detect your every move and heartbeat, to advanced brain chip implants that can sense your thoughts and translate them into physical moves with the assistance of exoskeletons, sensors bridge the gap between the physical world and digital systems. The rapid arrival of advanced Artificial Intelligence (AI) and Large Language Models (LLMs) has transformed almost every part of technology, especially data processing. However, the development of sensors remains a vitally important topic. Sensors form the foundation of innovation in electronics; novel sensors provide reliable data across a broad range of application areas and are a foundation for intelligent systems. Notably, knowing the capabilities and limitations of each sensor type is crucial for selecting the right sensor for a specific application, troubleshooting issues, and optimizing system performance. This book, entitled “Advanced Sensors for Real-Time Monitoring Applications II”, demonstrates developments of real sensors for a range of applications, including descriptions of fundamental principles of operation, concepts, theory, and practical validation of the results, as well as a review of current state-of-the-art and future directions. Full article

Capsular contracture (CC) remains the most common long-term complication of implant-based breast reconstruction (IBBR), significantly impacting cosmetic outcomes, patient satisfaction, and reoperation rates. Despite substantial advances in surgical technique, implant technology, and perioperative management, the incidence of clinically significant contracture persists at approximately 3–5% at five years in non-irradiated patients and escalates dramatically—to 20–50%—in those receiving postmastectomy radiation therapy (PMRT). The etiology is multifactorial, involving subclinical biofilm formation, a dysregulated host immune and foreign-body response, and radiation-induced fibrosis. This narrative review synthesizes contemporary evidence on the pathophysiology, clinical assessment, and modifiable risk factors for CC in IBBR, with particular emphasis on implant surface characteristics (smooth, textured, and polyurethane[PU]-coated), placement plane (prepectoral versus subpectoral), the role of acellular dermal matrices (ADMs), reconstruction timing (direct-to-implant versus two-stage), and the complex interplay with radiotherapy—including radiation timing, fractionation, and emerging delivery techniques. We also address ongoing controversies, including the lack of standardized objective diagnostic criteria, the comparative effectiveness of ADM versus PU-coated implants, and the optimal sequencing of radiation relative to reconstruction. By integrating the latest evidence from very recent major meta-analyses and national registries, this review provides an updated synthesis. We further propose an evidence-based clinical decision framework for CC risk mitigation. This review aims to inform individualized surgical decision-making and identify priority areas for future investigation. Full article

Objective: Deep Brain Stimulation (DBS) has been consolidated as a valid therapeutic option for advanced Parkinson’s disease (PD). The identification of specific targets can be achieved through different methods, including conventional direct and indirect methods. The aim of our multicentric study is to provide a comparison between these traditional methods and artificial intelligence (AI) in the ascertainment of the ideal targets. Materials and Methods: A total of eight patients, who received bilateral STN (subthalamic nucleus) DBS implantation between 2022 and 2023 were analyzed. Target coordinates were calculated based on the Schaltenbrand and Wahren atlases and the AI using the RebrAIn system during the planning phase; intraoperatively, the targets were either confirmed or adjusted according to microelectrode recordings (MERs). The differences in the three Cartesian axes of stereotactic coordinates (X, Y, and Z) according to these methods were evaluated and compared through non-parametric ANOVA Friedman test. Results: The results revealed significant agreement in the lateral–lateral coordinates (X, X′, X″), indicating stability in target determination along this axis across the methods. However, more substantial discrepancies were observed in the antero-posterior and cranio-caudal coordinates, suggesting lower consistency between the examined methodologies. Conclusions: Our preliminary study results suggest that, despite the challenges posed by interindividual anatomical variability and the limitations of imaging techniques, artificial intelligence has shown comparable values on the lateral–lateral X coordinates. The accuracy of predictive targeting using machine learning models needs to be validated by further studies, but the preliminary results appear to indicate a potential promising role for artificial intelligence in integrating the preoperative workflow. Full article