Bone Research Articles

Bacterial Cellulose/Graphene Oxide/Hydroxyapatite Biocomposite: A Scaffold from Sustainable Sources for Bone Tissue Engineering.

Bone tissue engineering demands advanced biomaterials with tailored properties. In this regard, composite scaffolds offer a strategy to integrate the desired functionalities. These scaffolds are expected to provide sufficient cellular activities while maintaining the required strength necessary for the bone repair for which they are intended. Hence, attempts to obtain efficient composites are growing. However, in most cases, the conventional production methods of scaffolds are energy-intensive and leave an impact on the environment. This work aims to develop a biocomposite scaffold integrating bacterial cellulose (BC), hydroxyapatite (HAp), and graphene oxide (GO), designated as "BC/HAp/GO". All components are sourced primarily from agricultural and food waste as alternative means. BC, known for its biocompatibility, fine fiber network, and high porosity, serves as an ideal scaffold material. HAp, a naturally occurring bone component, contributes osteoconductive properties, while GO provides mechanical strength and biofunctionalization capabilities. The biomaterials were analyzed and characterized using a scanning electron microscope, a X-ray diffractometer, and a Fourier transform infrared spectrometer. The produced biocomposite scaffolds were tested for thermal stability, mechanical strength, and biocompatibility. The results showed a nanofibrous, porous network of BC, highly crystalline HAp particles, and well-oxygenated GO flakes with slight structural deformities. The synthesized biocomposite demonstrated promising characteristics, such as increased tensile strength due to added GO particles and higher bioactivity through the introduction of HAp. These inexpensively synthesized materials, marked by suitable surface morphology and cell adhesion properties, open potential applications in bone repair and regeneration.

Concomitant Traumatic Macular Hole and Orbital Fracture.

To report 5 cases of concomitant traumatic macular hole (TMH) and orbital fracture, and discuss its incidence. This was a retrospective, observational study including all patients with orbital fracture who were referred to us from May 2013 to December 2023. Axial and coronal orbital computed tomographic images with bone and soft tissue window algorithms and optical coherence tomographic images were obtained from all patients. Among 1171 sides from 1152 patients with pure orbital blowout fractures, we found 5 sides from 5 patients (0.4%) with concomitant TMH. All trauma was caused by baseball/softball injury. One patient had a medial orbital wall fracture with TMH stage 1b. Two had orbital floor fracture with TMH stages 2 and 3. The other two had both orbital floor and medial orbital wall fractures with TMH stages 3 and 4. Orbital fracture was reduced in 3 patients. Two had spontaneous closure of TMH with no improvement in visual acuity, while one improved with pars plans vitrectomy and internal limiting membrane peeling. The incidence of concomitant TMH and orbital fracture is only 0.4%. The rarity of this association supports the protective role of orbital fractures in blunt trauma. Specific mechanisms of trauma, such as impacts from baseballs and softballs, may increase risk of such injuries.

Advances in Stem Cell Therapy: A Hope for Regenerative Medicine

Introduction Regenerative medicine has become a light at the end of the tunnel for countless patients who have suffered from diseases previously considered incurable. Stem cell therapy is central to this revolutionary progress and has already made huge advances in recent years. Stem cells have the potential to regenerate tissues, repair organs, and even modulate immune responses, making them a key to delivering innovative treatments for a broad spectrum of medical conditions. This editorial describes recent progress in stem cell therapy as well as its promise as a regenerative medicine[1]. Stem Cells have unique Properties. Stem cells have unique properties that make them of great value in therapeutic applications. This allows them to self-renew and differentiate into specialized cell types with immense possibilities of being used in treating degenerative diseases, tissue injuries, and even genetic disorders. Each type is classified broadly into embryonic stem cells (ESCs), adult stem cells (ASCs), and induced pluripotent stem cells (iPSCs) with particular advantages. For example, ESCs are pluripotent and can differentiate into almost any cell type, while the more accessible and less ethically controversial MSCs like the ASCs[2]. Pioneered most recently by Shinya Yamanaka, recent breakthroughs in iPSC technology have further revolutionized the field. IpsCs overcome many of the limitations of ESCs by reprogramming somatic cells into a pluripotent state. It has accelerated the development of patient-specific therapies – personalized regenerative solutions[3]. Stem Cell Therapy Success Stories Stem cell therapies have already had tremendous success in treating multiple different medical conditions. Therapies have also been shown to be effective in treating Parkinson’s disease, spinal cord injuries, and stroke in neurological disorders. Damaged neurons have been replaced with transplanted stem cells and lost functions have been restored[4]. While recent clinical trials using MSCs and iPSCs for stroke recovery have revealed improved motor function as well as reduced inflammation, they represent a great leap forward in this field. Repairing damaged heart tissue that results from myocardial infarction has been explored using cardiomyocyte transplantation from ESCs and iPSCs. In preclinical and clinical studies, these therapies not only support tissue regeneration but also enhance cardiac function and survival outcomes[5]. The differentiation of ESCs and iPSCs into insulin-secreting β cells for use in the treatment of type- 1 diabetes represents another major milestone in stem cell therapy. But β cells transplanted into the bloodstream can regulate blood glucose levels, and at last, this represents a realistic prospect of a cure[6, 7]. Unfortunately, hematopoietic stem cell transplantation (HSCT) remains the gold standard for treating blood-related disorders, such as leukemia, aplastic anemia, and immune deficiencies. HSCT has been further made safer and more effective by advances in gene editing technologies such as CRISPR-Cas9, which now allow for targeted genetic therapies. MSCs are being widely investigated in the orthopedic field for their potential to regenerate cartilage, bone, and muscle tissue. Stem cell therapy has shown a lot of promise in osteoarthritis, fractures, and tendon injuries, where the therapies help to speed up healing and reduce pain[8]. Challenges of Stem Cell Therapy Sure, the promise of stem cell therapy is undeniable, but a host of challenges must be overcome first to make it a mainstream clinical tool. Despite all of this, safety concerns remain paramount: tumorigenesis, immune rejection, and unintended differentiation. Equally important is standardization and regulation, which will help develop consistent protocols for stem cell isolation, culture, and transplantation with reproducible outcomes from clinical trials. In addition, stem cell therapies are very expensive, which limits access, especially in low and middle-income countries. However, ESCs have continued to raise ethical concerns, particularly in the area of ESCs, and therefore alternative sources such as iPSCs and adult stem cells are needed[9]. Future Directions Overcoming these challenges is a future challenge for bioengineering, nanotechnology, and gene editing. For example, 3D bio-printed tissues and organoids bring together stem cell technology and tissue engineering to provide functional tissues for transplantation. These innovations could change the way we deal with organ failure and more advanced medical conditions[10]. Conclusion Stem cell therapy enters into a new era of progressive continuous progress. With the continued expansion of clinical trials and increasing technology, stem cell therapies have the potential to transform the treatment landscape for many diseases and injuries. Still, there is plenty of work to be done, but the convergence of interdisciplinary innovations presents a strong foundation for hope. With the participation of scientists, clinicians, policymakers, and industry stakeholders, stem cell research can be translated into safe, effective, and accessible therapies benefiting millions of patients with the possibility to recover and improve their quality of life. Regenerative medicine has a promising future and stem cells are at the center of that progress. Through innovation and addressing current challenges, we can unleash the full power of stem cell therapies to provide transformative solutions to patients around the world.

Internal brace augmentation in elbow varus posteromedial rotatory instability (VPMRI) allows early rehabilitation and prevents stiffness.

Varus posteromedial rotatory instability (VPMRI) involves anteromedial coronoid fracture (AMCF), lateral ulnar collateral ligament (LUCL), and medial collateral ligament (MCL) injury. There is no general consensus regarding the surgical treatment, but most surgeons recommend internal fixation of the coronoid along with primary ligament repair. This methodology involves postoperative immobilization to allow ligament healing, occasionally associated with stiffness. Augmentation of one/or both collateral ligaments using a non-absorbable suture tape as an internal brace in VPMRI cases was the subject of the presented study. This method allows brace-free initiation of full elbow range of motion while protecting bony and soft tissue healing. 17 patients (13 males and four females) with VPMRI were treated in the center from 2017 to 2021 with internal brace augmentation of collateral ligament along with ORIF (Open reduction & internal fixation)/ reconstruction of the coronoid fragment. All patients were actively mobilized early after surgery. Patients who completed a minimum follow up of 24 months were included in the study. Clinical examination findings at follow-up assessment included ROM (range of motion) recording and instability testing, including special instability tests such as moving valgus stress test, lateral pivot shift test, Posterolateral rotatory drawer test, and gravity-assisted varus stress test. Disabilities of arm, shoulder and hand (DASH) score, Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), Visual Analogue Score (VAS), and SEV (Simple Elbow values) were assessed and noted at follow-up. At 43 months of mean follow-up, none of the patients had significant postoperative contracture, and none had any clinically apparent signs of instability or suffered subluxation or re-dislocation. Postoperative radiographs showed complete fracture/graft healing with no signs of subluxation in all patients. The mean range of motion of the patients was 6.20 (1.00-11.30) to 139.10 (136.20-142.00), with a mean Oxford elbow score (OES) of 42.0 (39.9-44.7). The mean DASH (Disability of Arm, Shoulder & Hand) score was 11.4 (6.7-16.1), the mean MEPS (Mayo Elbow Performance Score) was 91.2 (86.3-96.0), the mean Visual Analogue Score (VAS) score was 0.6 (0.1-1.2), and the mean Simple Elbow value (SEV) was 85.4% (81.1-89.8%). Internal brace augmentation with a non-absorbable suture tape in the setting of VPMRI is a safe and helpful adjunct to coronoid repair/reconstruction and primary ligament repair and allows early mobilization and recovery of elbow stability and range of motion.

Receptor Activator of Nuclear Factor Kappa-B-Expressing Mesenchymal Stem Cells-Derived Extracellular Vesicles for Osteoporosis Therapy.

The dynamic balance between bone resorption and formation is critical for maintaining healthy bone homeostasis. However, the receptor activator of the nuclear factor B ligand (RANKL) primarily stimulates mature osteoclasts to resorb bone, and its upregulation leads to osteoporosis in patients. Here, we designed RANK-expressing extracellular vesicles (EVs) derived from mesenchymal stem cells to maintain bone homeostasis in mice. This engineered EV (EV@R) effectively neutralizes excess RANKL in bone tissue due to the RANK-RANKL interaction, thereby attenuating osteoclast differentiation. Additionally, we found that miRNA-21a-5p in EV@R contributes to restoring bone metabolic homeostasis. We demonstrate the protective and therapeutic efficacy of EV@R against osteoporosis in the ovariectomy-induced osteoporosis mouse model with a lasting effect and minimal side effects. Our study provides an alternative way to use engineered EVs for bone homeostasis treatment.

Post-traumatic patellar tendon ossification in children: a case series

Background. Fractures of the bones that form the knee joint in children are quite rare, accounting for up to 6% of all bone fractures. These include avulsion fractures of the patellar apex as well as tibial tuberosity avulsion fractures, which may result in patellar tendon ossification. Based on literature, the ossification may also occur in cases of primary or chronic (complete or partial) patellar tendon tears. Such a complication is quite rare in pediatric traumatology; it requires differential diagnosis and various surgical tactics. The aim of the study is to present a clinical and radiological picture of post-traumatic patellar tendon ossification in children and its surgical treatment outcomes using a case series as an example. Methods. We present a monocenter retrospective series of 4 male patients. Anamnestic, clinical, radiological and histological data were analyzed. Results. The patients’ mean age was 14 (range, 11-16) years. In all cases, there was a history of trauma. Initially, after getting injured, the patients were treated for a knee injury. In one patient, as a result of his falling on 2 limbs, a bilateral pathology was observed; in other three cases, the pathology was unilateral. Flexion contracture and pain syndrome prevailed in the clinical picture. All patients underwent surgery ranging from excision of ossifications to excision of ossifications with reconstruction of tendon defects and refixation of the tibial tuberosity with osteosynthesis. In all cases, knee joint contracture was eliminated and the volume of movement was fully restored. Histology showed fragments of mature bone tissue represented by thinned bone beams with focal osteoclastic reaction and areas of endochondral ossification. Conclusions. The clinical picture of pediatric patients with patellar tendon ossification manifests in the form of a chronic cascade of symptoms and functional and topographic disorders: patellar tendon ossification, patella alta, anterior knee pain, flexion contracture and rectus femoris muscle hypotrophy. X-ray and MRI data determine a formation of bone density with uneven clear contours in the projection of the patellar tendon, along with patella alta and the Caton-Deschamps index increasing more than 1.3. The primary treatment method of the developed complication is the surgical one, which leads to the restoration of the full amplitude of movements in the knee joint.

Enhancement of the Mechanical Properties and Biological Performance of Hydroxyapatite Coating by Selenium and Fluorine Ion Codoping

Ion doping is a feasible method to improve the mechanical and biological properties of hydroxyapatite (HA) as an implant coating material. F and Se codoped HA (SeF‐HA) powder is synthesized with the method of chemical codeposition and directly used for coating preparation via suspension plasma spray technology. Various characterizations indicate that F and Se ions have been codoped into the HA structure by substituting OH− and PO43− groups, respectively. The SeF‐HA coatings exhibit excellent adhesion strength with the substrate, fully meeting the ISO requirement of 15 MPa. The dissolution behavior is investigated by immersing the coatings in simulated body fluid for different durations. The results show that the dissolution rate of the SeF‐HA coatings is lower than that of the single Se‐doped HA coating, suggesting an improvement in the stability of the SeF‐HA coating. The in vitro studies show that the SeF‐HA coating can promote the osteogenic activity of osteoblasts and has an antiproliferative effect on osteosarcoma cells. Based on these results, it can be concluded that the combined effects of Se and F can make suspension plasma sprayed HA coating a potential coating material for dental implants or for bone tissue repair in osteosarcoma patients.

Optimizing printability and mechanical properties of poly(3-hydroxybutyrate) (P3HB) biocomposite blends and their biological response to Saos-2 cells

Bone tissue engineering requires scaffolds with three-dimensional structures that facilitate vascularization and new tissue growth. 3D printing, especially through fused deposition modeling (FDM), has emerged as an effective method for creating complex structures with high reproducibility. Early research in this area demonstrated the potential of poly(ε-caprolactone) (PCL) and poly(L-lactide) (PLLA) scaffolds for bone regeneration. Recently, polylactide (PLA) and polyhydroxyalkanoates (PHAs) have garnered attention for their biocompatibility and ability to support cell proliferation. Among PHAs, poly(3-hydroxybutyrate) (P3HB) shows promise due to its intrinsic biocompatibility and resorbability, making it a candidate for FDM-based scaffold fabrication. In the presented study, we aim to develop and optimize a biocompatible P3HB-based composite material for bone tissue engineering, incorporating PLA, hydroxyapatite (HA), and the plasticizer Syncroflex3114 (SN) to enhance mechanical properties and printability. This composite was processed into filaments for 3D printing and characterized through thermal, mechanical, and biological evaluations. Using a design of experiment (DoE) approach, we investigated factors such as temperature performance, warping, degradation, and strength to determine the optimal composition for use in tissue engineering. Four optimal mixture compositions fulfilling the optimization criteria of having the most suitable properties for bone tissue engineering, namely the best printability and maximum mechanical properties,  were obtained. The mixtures were optimized specifically for minimum warping coefficient (0.5); maximum flexural strength (66.9 MPa); maximum compression modulus (2.4 GPa); and maximum compression modulus (2.3 GPa) with a warping coefficient of no more than one at the same time. In conclusion, the study shows a new possible way to effectively develop and test 3D printed P3HB-based scaffolds with specifically optimized material properties.

Polyetheretherketone Double Functionalization with Bioactive Peptides Improves Human Osteoblast Response

In recent years, the demand for orthopedic implants has surged due to increased life expectancy, necessitating the need for materials that better mimic the biomechanical properties of human bone. Traditional metal implants, despite their mechanical superiority and biocompatibility, often face challenges such as mismatched elastic modulus and ion release, leading to complications and implant failures. Polyetheretherketone (PEEK), a semi-crystalline polymer with an aromatic backbone, presents a promising alternative due to its adjustable elastic modulus and compatibility with bone tissue. This study explores the functionalization of sandblasted 3D-printed PEEK disks with the bioactive peptides Aoa-GBMP1α and Aoa-EAK to enhance human osteoblast response. Aoa-GBMP1α reproduces 48–69 trait of Bone Morphogenetic Protein 2 (BMP-2), whereas Aoa-EAK is a self-assembling peptide mimicking extracellular matrix (ECM) fibrous structure. Superficial characterization included X-ray photoelectron spectroscopy (XPS), white light interferometer analysis, static water contact angle (S-WCA), and force spectroscopy (AFM-FS). Biological assays demonstrated a significant increase in human osteoblast (HOB) proliferation, calcium deposition, and expression of osteogenic genes (RUNX2, SPP1, and VTN) on functionalized PEEK compared to non-functionalized controls. The findings suggest that dual peptide-functionalized PEEK holds significant potential for advancing orthopedic implant technology.

Editorial: Advances in artificial intelligence and machine learning applications for the imaging of bone and soft tissue tumors

Editorial: Advances in artificial intelligence and machine learning applications for the imaging of bone and soft tissue tumors

Tribological and Fatigue Behaviour of Ti-Nb-Zr-Sn Alloy through Powder Compacting: Novel Performance of High Niobium Alloys for Bone Tissue Compatibility

Biocompatible materials are natural or man-made substances kept in the body to turn a living cell into a working organ. Bone tissue and biocompatibility are emerging as an alternative approach to regenerating bone due to some distinct advantages over autografting and allografting. This research aimed to fabricate a novel porous scaffold Ti-Nb-Zr-Sn alloy that can be utilized as a bone substitute. Ti-Nb-Sn-Zr were selected by different weight ratios and synthesized using the powder metallurgy method. Zirconium (Zr) is incorporated to get enhanced biological performance. The elements Ti, Nb with Zr, and Sn are utilized due to their excellent biocompatibility with the human body. The Ti-35Nb-7Zr-4Sn alloy has high tensile strength between 1042 and 1603 MPa by ­increasing Zr and Nb weight ratios. In addition, 35% Nb/7% Zr with 4% Sn composite show improved hardness, which is beneficial for resembling bone tissue and die-casting fittings in automobile applications. Fatigue and wear analysis is conducted to help us understand the behaviour of the Ti-Nb-Zr-Sn alloy.

Development of New Chitosan-Based Complex with Bioactive Molecules for Regenerative Medicine

Background/Objectives: The development of new materials incorporating bioactive molecules for tissue regeneration is a growing area of interest. The objective of this study was to develop a new complex specifically designed for bone and skin tissue engineering, combining chitosan, ascorbic acid-2-magnesium phosphate (ASAP), and β-tricalcium phosphate (β-TCP). Methods: Chitosan and the complexes chitosan/ASAP and chitosan/ASAP/β-TCP were prepared in membrane form, macerated to a particulate format, and then subjected to characterization through Fourier transform infrared (FTIR) spectroscopy, optical and scanning electron microscopy (SEM), zeta potential, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Cell viability was evaluated through a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and with fluorescein diacetate (FDA) and propidium iodide (PI) staining in stem cells obtained from deciduous teeth. Statistical analyses were performed using analysis of variance (ANOVA), followed by Tukey’s test. Results: The FTIR results indicated the characteristic bands in the chitosan group and the complexation between chitosan, ASAP, and β-TCP. Microscopic characterization revealed a polydisperse distribution of micrometric particles. Zeta potential measurements demonstrated a reduction in surface charge upon the addition of ASAP and β-TCP to the chitosan matrix. TGA and DSC analyses further indicated complexation between the three components and the successful formation of a cross-linked structure in the chitosan matrix. Stem cells cultured with the particulate biomaterials demonstrated their biocompatibility. Statistical analysis revealed a significant increase in cell viability for the chitosan/ASAP and chitosan/ASAP/β-TCP groups compared to the chitosan control. Conclusions: Therefore, the chitosan/ASAP complex demonstrated potential for skin regeneration, while the chitosan/ASAP/β-TCP formulation showed promise as a biomaterial for bone regeneration due to the presence of β-tricalcium phosphate.

Modern possibilities of instrumental diagnostics of early stages of avascular osteonecrosis

Avascular osteonecrosis (AON) is a common condition that can occur at any age, but more often in young and able-bodied people. The disease leads to rapid destruction and collapse of the subchondral bone with subsequent formation of secondary osteoarthritis of the affected joint. The review presents modern methods of instrumental diagnostics of AON. Particular attention is paid to the detection of stage I AON. An approach to early diagnosis of AON is discussed that may change the misconception of viewing bone tissue edema as a sign characteristic only of AON and may improve differential diagnosis of the disease from other conditions and treatment outcomes.

Diagnostic and Prognostic/Therapeutic Significance of Comprehensive Analysis of Bone and Soft Tissue Tumors Using Optical Genome Mapping and Next-generation Sequencing.

Detecting somatic structural variants (SVs), copy number variants (CNVs), and mutations in bone and soft tissue tumors is essential for accurately diagnosing, treating, and prognosticating outcomes. Optical genome mapping (OGM) holds promise to yield useful data on SVs and CNVs but requires fresh or snap-frozen tissue. This study aimed to evaluate the clinical utility of data from OGM compared to current standard-of-care cytogenetic testing. We evaluated 60 consecutive specimens from bone and soft tissue tumors using OGM and karyotyping, FISH, gene fusion assays, and deep next-generation sequencing (NGS). OGM accurately identified diagnostic SVs/CNVs previously detected by karyotyping and FISH (specificity=100%). OGM identified diagnostic and pathogenic SVs/CNVs (∼23% of cases) undetected by karyotyping (cryptic/submicroscopic). OGM allowed detection and further characterization of complex structural rearrangements including chromoanagenesis (27% of cases) and complex 3-6-way translocations (15% of cases). In addition to identifying 321 SVs and CNVs among cases with chromoanagenesis events, OGM identified approximately 9 SVs and 12 CNVs per sample. A combination of OGM and deep NGS data identified diagnostic and pathogenic SVs, CNVs, and mutations in ∼98% of cases. Our cohort contained the most extensive collection of bone and soft tissue tumors profiled by OGM. OGM had excellent concordance with standard-of-care cytogenetic testing, detecting and assigning high-resolution genome-wide genomic abnormalities with higher sensitivity than routine testing. This is the first and largest study to provide insights into the clinical utility of combined OGM and deep sequencing for the pathologic diagnosis and potential prognostication of bone and soft tissue tumors in routine clinical practice.

Diagnostic Imaging of Primary Cutaneous Osteoma of the Forehead

Introduction: Osteoma cutis is a rare benign condition characterized by ectopic bone formation in the dermis or subcutaneous tissue. Typically, osteoma cutes result from inflammation, tumors, or scars. However, primary cases occasionally present with no apparent preceding lesion. Case Presentation: we report a case of primary osteoma cutis located on a 20-year-old woman's forehead. Diagnostic imaging revealed a nodule of bone tissue within the dermis and contiguous cartilage tissue, which was later histologically confirmed. The patient underwent surgical resection under local anesthesia and successfully recovered with no neurological symptoms or signs of recurrence 6 months after the surgery. Conclusion: We report this case because, to the best of our knowledge, there have been no reports of primary osteoma cutis with complete preoperative imaging findings.

Assessment of Stress Distribution Around Traditional and Sleeve Fixed Partial Denture Designs: Finite Element Analysis.

The aim of this research is to evaluate/compare the use of traditional versus sleeve fixed partial denture (PD) designs made from different materials on supporting structures. The comparison included three- and four-unit PD cases. Four finite element models are used in the research. The three-unit PD consists of the mandibular second premolar, first molar (as a pontic), and second molar. The four-unit PD includes the first premolar. The PD materials assessed were zirconia, E-max, and Celtra Duo. Bone has been simplified representing it as two cuboids. Each PD has been loaded to two cases over the pontic's central fossa: 300 N compressive, 150 N obliquely applied with 45 degrees forming 24 cases. The three-unit traditional and sleeve PDs material change showed a slight change in cortical bone stress under vertical loading. Under oblique loading, cortical bone Von Mises stresses were higher by about 12 to 15% more than vertical loading. On the other hand, the four-unit PDs showed minor effect by changing PD material, while using sleeve design PD can reduce the cortical bone stresses up to 20% in comparison to traditional PD design. The mucosa and spongy bone were negligibly affected by changing PD material, and the traditional and sleeve designs showed close values to each other. Superiority of sleeve design appeared by reducing cement layer stresses dramatically, while PD body material rigidity affects its response. Within the limitations of this study, the higher rigid PD material can dissipate loadings over it more preferably regarding its effect on the underlying structures. Sleeve PD design is equivalent to the traditional one for three-unit PDs, while it showed better performance with four-unit PDs. Zirconia three-unit PDs' bodies received the lowest stresses and redistributed and transferred the applied load to the underneath structures better than the other two tested materials. This finding was reversed with four-unit PDs.

Radiological assessment of extremity bone involvement in Erdheim-Chester disease: a systematic review of case reports.

To describe the clinical presentations and radiological manifestations of Erdheim-Chester disease (ECD) in the extremities, with particular emphasis on radiologic findings, as radiographs are typically the initial imaging modality used in clinical practice. Following the PRISMA guidelines, a comprehensive systematic search was performed across Scopus, PubMed, Web of Science, and Embase databases, covering case reports from inception until August 1, 2024. Included were studies with pathologically confirmed ECD (CD68 positive and CD1a negative) that were evaluated with at least one imaging modality and provided detailed descriptions of radiological findings. Out of 401 identified articles, 20 articles comprising 20 histologically confirmed cases of ECD met the inclusion criteria following screening and full-text review. Pathological reports were assessed for the presence of lipid-laden cells and Touton giant cells, which were identified in 84.2% and 75% of cases, respectively. Upper extremities were affected in 65% of cases and lower extremities in all cases. Symmetric involvement was observed in 84.6% of upper extremity cases and 84.2% of lower extremity cases. Radiological findings were categorized as pure sclerosis (53.3%) and cortical thickening (42.8%) identified as the most common findings. Clinical manifestations were assessed, with pain and swelling in the extremities being the most common symptoms, occurring in 70% of cases. The hallmark of ECD is bilateral, symmetric diaphyseal and/or metaphyseal osteosclerosis in the long tubular bones of the lower extremities. Epiphyseal sparing is observed in more than half of the patients.

Microstructural and Surface Texture Evaluation of Orthodontic Microimplants Covered with Bioactive Layers Enriched with Silver Nanoparticles

Bacterial infections are a common cause of clinical complications associated with the use of orthodontic microimplants. Biofilm formation on their surfaces and subsequent infection of peri-implant tissues can result in either exfoliation or surgical removal of these medical devices. In order to improve the properties of microimplants, hybrid coatings enriched with silver nanoparticles, calcium, and phosphorus were investigated. The present study aimed to assess the microstructure of commercially available microimplants composed of a medical TiAlV (Ti6Al4V) alloy covered with organic–inorganic layers obtained by the sol–gel method using the dip-coating technique. The microstructures and elemental surface compositions of the sterile, etched, and layer-modified microimplants were characterized by scanning electron microscopy with X-ray energy-dispersive spectroscopy (SEM-EDS). Elements such as silver (Ag), calcium (Ca), phosphorus (P), silicon (Si), oxygen (O), and carbon (C) were detected on the microimplant’s surface layer. The SEM observations revealed that control microimplants (unetched) had smooth surfaces with only manufacturing-related embossing, while etching in hydrofluoric acid increased the surface roughness and introduced fluoride onto the microimplants. Layers with only silver nanoparticles reduced the roughness of the implant surface, and no extrusion was observed, while increased roughness and emerging porosity were observed when the layers were enriched with calcium and phosphorus. The highest roughness was observed in the microimplants etched with AgNPs and CaP, while the AgNPs-only layer showed a reduction in the roughness average parameter due to lower porosity. Enhancing the effectiveness of microimplants can be achieved by applying selective surface treatments to different parts. By keeping the outer tissue contact area smooth while making the bone contact area rough to promote stronger integration with bone tissue, the overall performance of the implants can be significantly improved.

TINJAUAN SISTEMATIS HISPATOLOGI GOUT ARTRITIS: PERAN SEL IMUN DALAM PROSES INFLAMASI DAN KERUSAKAN JARINGAN

Gout arthritis is a joint inflammation caused by increased uric acid levels, leading to the formation of monosodium urate (MSU) crystals. The study aimed to deepen the understanding of the role of MSU crystals in triggering both acute and chronic inflammatory responses, as well as the formation of tophi, which damage joint and bone tissues. The method used is the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The reviewed articles were obtained from the Science Direct, Semantic Scholar, and PubMed databases using the keywords “Gout Arthritis,” “Histopathology,” “Inflammation,” and “Tophus.” The publication period was limited to 2019-2024. Out of 745 articles found, 12 were selected based on inclusion criteria, which included experimental, observational, and case study reports. The results show that MSU crystals induce inflammation through the infiltration of inflammatory cells such as neutrophils and macrophages. In chronic Gout, the formation of tophi, granulomatous lesions with a crystalline core, leads to bone and joint destruction. Understanding the histopathological aspects is crucial for more accurate diagnosis and more effective management of Gout arthritis. The progression of the disease is related to acute and chronic inflammation, as well as the destructive effects of tophi on joints and bones. In conclusion, MSU crystals play a significant role in triggering inflammation and tissue damage in Gout arthritis, and understanding histopathology can improve diagnostic accuracy and therapeutic efficacy.

The role of osteoprotegerin (OPG) in exercise-induced skeletal muscle adaptation

Abstract Objectives The purpose of this narrative review is to offer an updated perspective on the current research on the glycoprotein Osteoprotegerin (OPG), including its potential therapeutic impact and mechanisms of action, and interaction with bone and muscle tissues. Content As health and social care advances people are living longer, with projections suggesting that in 2050 there will be 2 billion people who are aged over 60 years. Yet musculoskeletal health still declines into older age and as a result there is an increase in the proportion of older populations that spend more time with persistent disabilities. Although physical exercise is repeatedly demonstrated to minimise detrimental effects of ageing, it is not always a feasible intervention, and other directions must be considered. Summary and outlook OPG, a glycoprotein decoy receptor for the receptor activator of nuclear factor kappa-β ligand (RANKL) is a key regulator of bone formation yet emerging evidence has presented its potential to offer positive outcomes in regard to the preservation of skeletal muscle mass and function. Animal models have shown that OPG levels increase during exercise, and independently acts to restore losses of muscle strength and reduce bone resorption. Interventions to increase circulating OPG alongside exercise may act as a therapeutic target to combat the decline in quality of life in older age in humans. Further research is needed on the mechanisms of its action and interaction in humans in combination with exercise.