Search Results (18,499)

The Zn-3Mg alloy fabricated by laser powder bed fusion (LPBF) additive manufacturing is widely used in biomedical implants due to its excellent biocompatibility and favorable mechanical strength. However, its application is hindered by limited ductility and a relatively rapid degradation rate. This study investigated the influence of annealing heat treatment on the microstructure, mechanical properties, and degradation behavior of LPBF-fabricated Zn-3Mg porous implants. A systematic analysis of various annealing parameters revealed the evolution mechanisms of the microstructure, including grain coarsening and the precipitation and distribution of secondary phases Mg₂Zn₁₁ and MgZn₂. The results indicated that appropriate annealing conditions (such as 250 °C for 1 h) significantly enhanced the compressive strain by 10%, while maintaining a high compressive strength of 24.72 MPa. In contrast, excessive annealing temperatures (e.g., 365 °C) promoted the formation of continuous brittle phases along grain boundaries, leading to deterioration in mechanical performance. The degradation behavior analysis illustrated a substantial increase in the corrosion rates from 0.6973 mm/year to 1.00165 mm/year after annealing at 250 °C for 0.5 h and 365 °C for 1 h, which can be attributed to the micro-galvanic effect induced by the presence of fine or coarse secondary phases that promoted localized corrosion. This study demonstrated synergistic regulation of mechanical properties and degradation behavior in the Zn-3Mg porous structures through optimized heat treatment, thereby providing essential theoretical and experimental supports for the clinical application of biodegradable zinc-based implants. Full article

Background: Prosthesis patient mismatch (PPM) is associated with poor outcomes in literature. Prevention of mismatch is crucial in aortic valve replacement, yet there is no current consensus on preventative strategies. Objectives: This study introduces a novel clinical framework, nomenclature, and algorithm for contemporary Heart Team practice, providing a systematic approach for a tailored surgical strategy to anticipate and prevent mismatch. Methods: This was a single-center observational study performing a descriptive analysis of an evolving practice on 100 consecutive patients operated for aortic valve stenosis between 2020 and 2024. A step-by-step No-Mismatch algorithm was designed for the Heart Team to triage, discuss, and decide the surgical strategy prior to the procedure, identifying patients at risk of mismatch, and guiding the surgeon’s plan to prevent PPM and consider a Lifetime Valve Strategy. Results: The algorithm identified 26% of patients at risk of mismatch requiring a No-Mismatch strategy, and 20% at risk of small valve implantation requiring a Lifetime Valve Strategy. This cohort included 51 urgent cases. Valve pathology included 35% congenital, 59% degenerative, 1% rheumatic, and 5% redo operations. Valve implant type: 82% biological, including 29% rapid deployment valve (RDV), and 18% mechanical; 20% of patients required aortic root enlargements (AREs). Pre-, intra-, and post-operative data are presented. Mortality occurred at 1%. All degrees of mismatch were prevented. Conclusions: The surgeon was able to predict mismatch and elected either ARE, RDV, or a mechanical valve as required. Patient selection and a No-Mismatch Heart Team approach are essential to provide a tailored strategy for aortic valve interventions. Full article

Background: Antibiotic tolerance in Staphylococcus aureus biofilms poses a major clinical challenge in prosthetic joint infections (PJIs). This study aimed to characterize the antibiotic tolerance of clinical S. aureus isolates recovered from cases of PJI under different stress conditions, including biofilm formation and antibiotic exposure. The correlation between tolerance level, the presence of specific tolerance-related genes, and clinical outcome was also evaluated. Methods: Twelve clinical S. aureus isolates were analyzed. To assess tolerance, the TDtest was used on exponentially growing bacteria, 48 h biofilms, and biofilms treated with levofloxacin and/or rifampin. Whole-genome sequencing was performed to identify tolerance-associated genes. Results: All isolates were phenotypically susceptible to rifampin and levofloxacin. Although all strains exhibited basal tolerance levels, biofilm formation led to heightened antibiotic tolerance, particularly those treated with rifampin as compared to levofloxacin: 29.5 vs. 17 (p = 0.01). Rifampin tolerance in biofilm-embedded bacteria was significantly higher in isolates from patients with treatment failure (p < 0.0001). Levofloxacin tolerance showed no significant association with clinical outcomes. There was no correlation between reduction in biofilm bacterial burden after treatment and tolerance levels. Genomic analysis identified associations between higher levofloxacin tolerance and the presence of sspA and leuS in biofilm isolates, and between rifampin tolerance and prs and pgm. Conclusions: In this study, clinical S. aureus strains isolated from prosthetic joint infections exhibited considerable inter-strain variability in antibiotic tolerance, particularly under biofilm conditions. Elevated rifampin tolerance in biofilm-embedded bacteria was associated with poor clinical outcomes, underscoring the need for tolerance assessment beyond standard susceptibility testing. Full article

Background/Objectives: Chronic bone infections require local antimicrobial delivery to achieve high drug concentrations while limiting systemic toxicity. Silver ion-doped calcium phosphate synthetic bone grafts have been proposed as carriers for local antimicrobial release. This study aimed to evaluate the efficacy and safety of a silver ion-doped synthetic bone graft in patients with chronic osteomyelitis, infected nonunion, or implant-related bone infection. Methods: This retrospective cohort included 12 adults who underwent surgery for chronic osteomyelitis or implant-associated infection. All patients received thorough debridement, removal of infected implants when present, and filling of bone defects with a silver ion-doped calcium phosphate graft. The median age was 38 years, and follow-up was 12 months. Clinical and radiographic outcomes, liver and kidney function tests, and blood silver levels were assessed pre- and postoperatively. Results: Infection eradication was achieved in 11 of 12 patients (90%) at 12 months. Functional recovery, defined as return to normal daily activities, occurred within 3–5 months. Bone union was observed in all but one patient within 3–6 months, and no graft resorption was detected at one year. No significant differences in liver or kidney function tests were found compared with the control group (p > 0.05), and blood silver levels remained within normal limits. Conclusions: At 12-month follow-up, silver ion-doped synthetic bone grafts showed encouraging safety and efficacy in the treatment of chronic osteomyelitis. These findings suggest that silver-doped grafts may represent a useful option for one-stage treatment of osteomyelitis. Full article

The long-stop rule, under the UK Consumer Protection Act (CPA) 1987, imposes a 10-year limitation period for product liability claims, providing legal certainty for manufacturers and consumers. However, this timeframe is increasingly problematic in the case of medical devices, particularly implantable ones, which can fail decades after implantation. This review considers an extension to the long-stop period for medical devices, emphasising the need for patient protection, legal clarity, and reduced clinician burden, and contrasts the current UK system with the EU’s proposed 25-year long-stop period under the recently implemented 2024 Product Liability Directive. Through case studies, including surgical mesh and orthopaedic implants, the discussion highlights the challenges posed by delayed failure modes and the resulting difficulties in seeking redress within the 10-year window. Lastly, the role of publicly funded redress schemes and the evolving legal landscape are examined, underscoring the importance of reconsidering the current statutory limitations. Extending the long-stop period, combined with the use of explant analysis to evaluate defective medical devices, is proposed as a means to enhance patient safety and align with ongoing advancements in medical technology and regulation. Full article

Background: The objective assessment of hearing in non-cooperative populations, such as neonates, remains a challenge. While Brainstem Evoked Response Audiometry (BERA) is the gold standard, its sensitivity to motion artifacts necessitates alternatives. Objective: This scoping review maps the current literature on functional near-infrared spectroscopy (fNIRS) as a supplementary method in objective audiometry. Data Synthesis: fNIRS shows potential to detect cortical hemodynamic responses, particularly to complex stimuli like speech, which BERA cannot fully assess. Key advantages include motion tolerance and suitability for pediatric and cochlear implant populations. However, the literature reveals significant heterogeneity in stimulation protocols and data processing. Evidence suggests fNIRS is better suited for assessing higher-level auditory processing rather than replacing BERA for threshold estimation. Conclusions: fNIRS is a promising complementary tool. However, due to the lack of standardized protocols and large-scale validation studies, it is not yet a direct clinical replacement for BERA. Future work must focus on protocol standardization and establishing robust normative data. Full article

Background/objectives: Zirconia dental implants are increasingly recognised as an alternative to titanium implants due to their biocompatibility and aesthetics. Initially developed as one-piece systems, zirconia implants have evolved into two-piece designs with different platform levels; however, comparative data on their primary and secondary stability– particularly as assessed by resonance frequency analysis (RFA)—and marginal bone dynamics remain limited. This case series aimed to evaluate the implant stability and marginal bone changes of two-piece zirconia implants with bone-level (BL) and tissue-level (TL) platforms in patients missing maxillary premolars. Methods: Thirteen zirconia implants (n = 13; 7 BL, 6 TL; Z5-TL/Z5-BL, Z-Systems, Switzerland) were placed in 11 patients with healed ridges. The implant stability quotient (ISQ) was measured immediately after insertion and before prosthetic loading. Lithium disilicate crowns were cemented after four months, and follow-ups were conducted for an average of 35 months (SD = 12). Results: Initial ISQ values ranged from 73 to 79, increasing to 76–84 at 3–4 months, indicating high implant stability for both BL and TL implants. The extent of marginal bone loss (MBL) after two years was greater around BL implants (mean 0.46 mm) compared to TL implants (mean 0.2 mm), although probing depths and bleeding on probing remained minimal in both groups, with only one TL implant showing gingival recession. Conclusions: Over a short observation period, two-piece zirconia implants with tissue-level platforms appeared to demonstrate superior marginal tissue stability. Further, larger-scale controlled studies are required to confirm these preliminary observations. Full article

Over the past decades, coronary revascularization has evolved dramatically with the introduction of bioresorbable scaffolds (BRSs), designed to provide temporary vessel support, elute antiproliferative drugs, and then fully resorb, ideally restoring natural vasomotion and eliminating long-term foreign-body reactions. Early enthusiasm for first-generation polymeric devices, such as the Absorb bioresorbable vascular scaffold, was tempered by increased rates of scaffold thrombosis and late adverse events, largely attributed to thick struts, suboptimal implantation techniques, and unpredictable degradation kinetics. Subsequent developments in polymeric (e.g., MeRes-100, NeoVas) and metallic magnesium-based scaffolds (e.g., Magmaris) have focused on thinner struts, improved radial strength, and refined resorption profiles. Clinical trials and meta-analyses, including ABSORB, AIDA, BIOSOLVE, and BIOSTEMI, reveal that optimized procedural strategies, especially the “PSP” approach (Prepare–Size–Post-dilate) and routine intravascular imaging, substantially reduce thrombosis and restenosis rates, aligning outcomes closer to those of contemporary drug-eluting stents (DESs). Nonetheless, challenges persist regarding inflammatory responses to degradation by-products, mechanical fragility in complex lesions, and patient selection. Ongoing innovations include hybrid polymer–metal designs, stimuli-responsive drug coatings, and AI-assisted imaging for precision implantation. While early-generation BRSs demonstrated both promise and pitfalls, next-generation platforms show steady progress toward achieving the dual goals of transient scaffolding and long-term vessel restoration. The current trajectory suggests that bioresorbable technology, supported by optimized technique and material science, may soon fulfill its original vision; offering safe, effective, and fully resorbable alternatives to permanent metallic stents in coronary artery disease. This review provides an updated synthesis of the design principles, clinical outcomes, and procedural considerations of drug-eluting bioresorbable scaffolds (BRSs). It integrates recent meta-analytic evidence and emerging insights on device mechanics, including the influence of strut thickness on radial strength and the potential role of non-invasive imaging in pre-implantation planning. Special focus is given to magnesium-based scaffolds and future directions in patient selection and implantation strategy. Full article

Background: The oncologic safety of dental implants (DIs) in patients with oral field cancerization (OFC) remains uncertain. Increasing reports of oral squamous cell carcinoma (OSCC) developing adjacent to DIs have raised concerns regarding the interaction between implants, chronic inflammation, and genetically altered mucosa. Methods: A comprehensive PubMed/MEDLINE search was performed through June 2025 to identify English- or Spanish-language publications reporting primary OSCC occurring in proximity to DIs. Extracted variables included patient demographics, tumor site, clinical presentation, presence of oral potentially malignant disorders (OPMD) or prior OSCC, peri-implant inflammation, management, and outcomes. Cases describing clinical features compatible with field-altered mucosa (e.g., OPMD or prior OSCC) were evaluated descriptively, recognizing that formal histopathologic or molecular evidence of OFC was rarely reported. Results: A total of 105 implant-associated OSCC cases were identified. The mean patient age was 66.8 years (range: 40–90), with a female predominance (1.3:1). The mandible was the most frequently involved site (86.7%). A prior history of OPMD or OSCC was reported in 53 patients (50.5%), and peri-implantitis preceding diagnosis in 21 cases (19.0%). The most common clinical presentations were exophytic (59.0%) and ulcerated (37.1%) lesions, frequently mimicking peri-implantitis and contributing to diagnostic delay. Reported outcomes included recurrence in 11 cases (10.5%) and death in 13 cases (12.4%). Conclusions: Current evidence suggests that implant-associated OSCC frequently occurs in patients with pre-existing mucosal alterations and may be influenced by the interaction of field cancerization with local inflammatory and mechanical factors. Implant rehabilitation in individuals with OPMD, prior OSCC, or epithelial dysplasia should be undertaken cautiously, with rigorous long-term surveillance to ensure oncologic safety. Full article

Background: In recent years, prepectoral implant-based breast reconstruction supported by acellular dermal matrices (ADMs) has become an increasingly adopted alternative to submuscular techniques. Although this approach can improve patient comfort and aesthetic outcomes, fluid accumulation around the implant remains one of the most frequent and clinically relevant complications. Our unit progressively modified the handling and wrapping of the Braxon^® ADM with the aim of optimizing pocket configuration and reducing seroma formation. Methods: We performed a retrospective analysis of consecutive patients who underwent immediate prepectoral, direct-to-implant breast reconstruction with Braxon^® ADM at our institution between October 2019 and January 2025. Two techniques were compared: a standard full-wrap configuration and a modified approach in which the posterior ADM sheet is trimmed and only anterior coverage is maintained, with fenestrations created in the anterior wall. Clinical data and postoperative complications, including seroma rates, were recorded and compared between groups. Categorical variables were summarized as counts and percentages, and continuous variables as means and standard deviations. The primary comparison between techniques was performed on the presence of at least one postoperative complication using Fisher’s exact test, and odds ratios (OR) with 95% confidence intervals (CI) were calculated where appropriate. A p-value <0.05 was considered statistically significant. Results: A total of 138 direct-to-implant prepectoral reconstructions were included, 90 performed with the standard full-wrap technique and 48 with the modified wrapping approach. The overall complication rate was 27.8% (25/90) in the standard group and 10.4% (5/48) in the new-technique group. Seroma occurred in 8 patients (8.9%) in the standard group and in 1 patient (2.1%) in the modified-technique group. Fisher’s exact test demonstrated a significantly lower overall complication rate in the modified-technique cohort (10.4% vs. 27.8%; p = 0.02; OR 3.31; 95% CI 1.18–9.31), indicating that patients treated with the standard technique had approximately 3.3-fold higher odds of developing at least one complication than those treated with the modified technique. Conclusions: Anterior-only ADM coverage with selective trimming of the posterior sheet and fenestration of the anterior wall appears to reduce complications, particularly seroma, in ADM-assisted prepectoral breast reconstruction. Small technical refinements in ADM handling and pocket configuration, combined with a structured drainage protocol, may substantially improve postoperative outcomes in this setting. Full article

Background/Objectives: Coronary artery disease (CAD) and aortic stenosis (AS) frequently coexist and share similar pathophysiological pathways, including inflammation, lipid deposition, and extracellular matrix remodeling. Trace elements are involved in cellular and physiological processes, playing regulatory and signaling roles. Their concentrations may be altered in various pathological conditions. The aim of our study was to compare trace metal concentrations in patients with severe aortic stenosis with and without coexisting coronary artery disease. Methods: In 53 patients (25 male, 47.2%, median age of 78 (75–81) years) with severe aortic stenosis, CAD coexistence and progression were analyzed based on the most recent coronary angiography report and history of revascularization. Blood samples for trace element analysis were collected prior to the implantation of the prosthesis, from the peripheral artery and by the pigtail catheter at the aortic root. Results: Twenty-six patients presented any degree of CAD, and were further differentiated into more advanced disease stages. The analysis found that patients with CAD had lower median concentrations of aluminum and calcium in the peripheral blood, and manganese and selenium in the aorta. Furthermore, in most advanced CAD patients, the concentration of magnesium, calcium, nickel, and copper in peripheral blood, along with chromium and selenium in aortic blood, was found to be lower compared to non-CAD patients. Lower selenium in aortic blood samples was predictive of an advanced stage of CAD. Conclusions: Patients with severe aortic stenosis and coexisting CAD present significantly lower blood concentrations of trace elements compared to those with the isolated disease. Full article

Atrial fibrillation (AF) is the most common sustained arrhythmia and a growing global health burden, yet conventional monitoring with Holter devices, event recorders and implantable loop recorders often fails to adequately capture recurrence. Rapid advances in digital health, wearable biosensors and artificial intelligence (AI) have transformed consumer smartwatches and wearables into potential clinical tools capable of continuous, real-world rhythm surveillance. This narrative review synthesizes contemporary evidence on smartwatch-based AF monitoring, spanning core technologies—photoplethysmography, single-lead electrocardiography and AI fusion algorithms—and validation studies across post-ablation follow-up. Compared with traditional modalities, smartwatch-based AF monitoring demonstrates improved detection of AF recurrence, enhanced characterization of AF burden, symptom–rhythm correlation, and greater patient engagement. At the same time, key limitations are critically examined, including motion artifacts, false-positive alerts, short recording windows, adherence dependence, digital literacy and access gaps, as well as unresolved issues around regulation, interoperability and data privacy. By integrating engineering advances with guideline-directed care pathways, smartwatch-based AF monitoring holds promise to complement, rather than immediately replace, established diagnostic tools and to enable more proactive, individualized AF management. Future work must focus on robust clinical validation, equitable implementation and clear regulatory frameworks to safely scale these technologies. Full article

Background: In the treatment of dentofacial deformities, miniplates and screws made of titanium and its alloys (Ti6Al4V) are currently used for osteosynthesis of bone segments, which is due to the high biocompatibility of these materials. Despite the unquestionable advantages of titanium implants, there is an ongoing discussion about their potential negative impact on the human body, both at the implantation site and systemically. This study aimed to assess the influence of titanium fixations (miniplates and screws) on the texture and to identify the texture features that vary in the surrounding bone tissue. Methods: The orthopantomograms were obtained from 20 patients who were treated at the Department of Maxillofacial and Plastic Surgery, University of Bialystok. Regions of Interest (ROIs) of bone tissue surrounding titanium fixations in the maxilla and mandible were annotated using separate masks and compared to healthy areas of the same structures in the same patients. The images were independently filtered using Mean, Median, and Laplacian Sharpening filters, followed by analysis of the texture parameters obtained through methods such as First-Order Statistics (FOS), the Gray-Level Co-occurrence Matrix (GLCM), Neighbouring Gray Tone Difference Matrix (NGTDM), Gray-Level Dependence Matrix (GLDM), Gray-Level Run Length Matrix (GLRLM), and Gray-Level Size Zone Matrix (GLSZM). Results: The results showed that FOS, GLCM, and GLDM provide the most informative features for quantitative assessment of the areas around titanium fixations, and that smoothing filters reduce measurement noise and artifacts. Conclusions: The findings confirm that texture analysis can support the diagnosis of structural alterations in the bone surrounding titanium fixations, in both the maxilla and mandible. Full article

Background and Objectives: Unstable distal clavicle fractures (Neer type II) have a relatively high risk of nonunion and often require operative fixation. Hook plates are widely used, particularly when the distal fragment is small or comminuted, because they provide strong vertical stability. However, hook plates are associated with subacromial irritation, acromial wear, and the need for routine implant removal. Distal locking plates with supplementary cerclage augmentation can achieve fixation without subacromial impingement and may reduce implant-related complications. This study aimed to compare clinical and radiologic outcomes of hook plates versus locking plates with or without cerclage augmentation for Neer type II distal clavicle fractures. Materials and Methods: In this single-center retrospective cohort, adult patients with Neer type II distal clavicle fractures who underwent open reduction and internal fixation between March 2021 and August 2022, with ≥6 months of follow-up, were reviewed. Patients were allocated into two groups according to implant: hook plate (Group 1, n = 16) and distal locking plate with or without cerclage augmentation (Group 2, n = 26). Primary outcomes were complication rate, radiographic union, and shoulder range of motion (ROM). Secondary outcomes included pain (PVAS) and functional scores (SANE, ASES, Constant, UCLA). Results: Forty-two patients were analyzed (locking n = 26, hook n = 16). Groups were comparable in age (51.3 ± 16.0 vs. 54.4 ± 17.1 years), follow-up (7.0 ± 4.0 vs. 8.4 ± 4.3 months), sex distribution, smoking status, and mechanism of injury. Radiographic union was achieved in 24/26 (92.3%) patients in the locking group and 14/16 (87.5%) in the hook group; two cases of nonunion or reduction failure occurred in each group (p = 0.612). Final patient-reported outcomes and ROM were similar between groups (e.g., ASES 68.2 ± 15.5 vs. 64.4 ± 18.3, Constant 57.3 ± 9.5 vs. 44.9 ± 20.5; all p > 0.05). Forward flexion tended to be higher in the locking group (138.9 ± 28.0° vs. 113.3 ± 36.7°, p = 0.182), although without statistical significance. No deep infection, peri-implant fracture, or hardware failure requiring unplanned revision was observed. Subacromial wear was identified in four patients (25%) in the hook plate group, whereas no such change was observed in the locking group. Conclusions: Both hook plates and distal locking plates (±cerclage) provided high union rates and satisfactory functional outcomes for Neer type II distal clavicle fractures. However, hook plates were associated with subacromial wear, whereas locking plate constructs avoided subacromial complications. When distal fragment purchase is feasible—or can be supplemented with cerclage augmentation—locking plate fixation represents a reliable first-line option, with hook plates reserved for cases with minimal distal bone stock or complex comminution. Full article

The rapid advancement of high-performance electronics has intensified the demand for wide-bandgap semiconductor materials capable of operating under high-power and high-temperature conditions. Among these, silicon carbide (SiC) has emerged as a leading candidate due to its superior thermal conductivity, chemical stability, and mechanical strength. However, the high cost and complexity of SiC wafer fabrication, particularly in slicing and exfoliation, remain significant barriers to its widespread adoption. Conventional methods such as wire sawing suffer from considerable kerf loss, surface damage, and residual stress, reducing material yield and compromising wafer quality. Additionally, techniques like smart-cut ion implantation, though capable of enabling thin-layer transfer, are limited by long thermal annealing durations and implantation-induced defects. To overcome these limitations, ultrafast laser-based processing methods, including laser slicing and stealth dicing (SD), have gained prominence as non-contact, high-precision alternatives for SiC wafer exfoliation. This review presents the current state of the art and recent advances in laser-based precision SiC wafer exfoliation processes. Laser slicing involves focusing femtosecond or picosecond pulses at a controlled depth parallel to the beam path, creating internal damage layers that facilitate kerf-free wafer separation. In contrast, stealth dicing employs laser-induced damage tracks perpendicular to the laser propagation direction for chip separation. These techniques significantly reduce material waste and enable precise control over wafer thickness. The review also reports that recent studies have further elucidated the mechanisms of laser–SiC interaction, revealing that femtosecond pulses offer high machining accuracy due to localized energy deposition, while picosecond lasers provide greater processing efficiency through multipoint refocusing but at the cost of increased amorphous defect formation. The review identifies multiphoton ionization, internal phase explosion, and thermal diffusion key phenomena that play critical roles in microcrack formation and structural modification during precision SiC wafer laser processing. Typical ultrafast-laser operating ranges include pulse durations from 120–450 fs (and up to 10 ps), pulse energies spanning 5–50 µJ, focal depths of 100–350 µm below the surface, scan speeds ranging from 0.05–10 mm/s, and track pitches commonly between 5–20 µm. In addition, the review provides quantitative anchors including representative wafer thicknesses (250–350 µm), typical laser-induced crack or modified-layer depths (10–40 µm and extending up to 400–488 µm for deep subsurface focusing), and slicing efficiencies derived from multi-layer scanning. The review concludes that these advancements, combined with ongoing progress in ultrafast laser technology, represent research opportunities and challenges in transformative shifts in SiC wafer fabrication, offering pathways to high-throughput, low-damage, and cost-effective production. This review highlights the comparative advantages of laser-based methods, identifies the research gaps, and outlines the challenges and opportunities for future research in laser processing for semiconductor applications. Full article