Bone Regions Research Articles

Interactive segmentation for accurately isolating metastatic lesions from low-resolution, large-size bone scintigrams.

Bone is a common site for the metastasis of malignant tumors, and Single Photon Emission Computed Tomography (SPECT) is widely used to detect these metastases. Accurate delineation of metastatic bone lesions in SPECT images is essential for developing treatment plans. However, current clinical practices rely on manual delineation by physicians, which is prone to variability and subjective interpretation. While computer-aided diagnosis (CAD) systems have the potential to improve diagnostic efficiency, fully automated segmentation approaches frequently suffer from high false positive rates, limiting their clinical utility.
Approach: This study proposes an interactive segmentation framework for SPECT images, leveraging the deep convolutional neural networks (DCNN) to enhance segmentation accuracy. The proposed framework incorporates a U-shaped backbone network that effectively addresses inter-patient variability, along with an interactive attention module that enhances feature extraction in densely packed bone regions.
Main results: Extensive experiments using clinical data validate the effectiveness of the proposed framework. Furthermore, a prototype tool was developed based on this framework to assist in the clinical segmentation of metastatic bone lesions and to support the creation of a large-scale dataset for bone metastasis segmentation.
Significance: In this study, we proposed an interactive segmentation framework for metastatic lesions in bone scintigraphy to address the challenging task of labeling low-resolution, large-size SPECT bone scans. The experimental results show that the model can effectively segment the bone metastases of lung cancer interactively. In addition, the prototype tool developed based on the model has certain clinical application value.

Automated detection of traumatic bleeding in CT images using 3D U-Net# and multi-organ segmentation.

Traumatic injury remains a leading cause of death worldwide, with traumatic bleeding being one of its most critical and fatal consequences. The use of whole-body computed tomography (WBCT) in trauma management has rapidly expanded. However, interpreting WBCT images within the limited time available before treatment is particularly challenging for acute care physicians. Our group has previously developed an automated bleeding detection method in WBCT images. However, further reduction of false positives (FPs) is necessary for clinical application. To address this issue, we propose a novel automated detection for traumatic bleeding in CT images using deep learning and multi-organ segmentation; Methods: The proposed method integrates a three-dimensional U-Net# model for bleeding detection with an FP reduction approach based on multi-organ segmentation. The multi-organ segmentation method targets the bone, kidney, and vascular regions, where FPs are primarily found during the bleeding detection process. We evaluated the proposed method using a dataset of delayed-phase contrast-enhanced trauma CT images collected from four institutions; Results: Our method detected 70.0% of bleedings with 76.2 FPs/case. The processing time for our method was 6.3 ± 1.4 min. Compared with our previous ap-proach, the proposed method significantly reduced the number of FPs while maintaining detection sensitivity.

Artificial light at night effects glucose metabolism in the developing jawbone by inhibiting melatonin secretion

Objective: To investigate the effects of artificial light at night on the growth of mandibles in mice and its regulatory mechanisms. Methods: A mouse model of artificial light at night (night light pollution group) and normal lighting (normal light group) was established by controlling light exposure time, with 4 mice in each group. Micro-CT was employed to analyze the differences in bone quantities of the mandibles between the two groups. Real-time fluorescence quantitative PCR (RT-qPCR) was used to examine the expression levels of osteogenic differentiation and metabolism-related genes in the cortical bone and condylar ossification center of the mandibles. Enzyme-linked immunosorbent assay was utilized to assess the diurnal variation of serum melatonin concentrations between the two groups. The artificial light at night experimental group received daily timed injections of a defined dose of melatonin to restore the diurnal variation of serum melatonin concentration in the mice, while the normal light group and the artificial light at night control group received the same volume of saline. Bone quantities, mandibular tissue morphologies, ossification differentiation in the condylar region and cortical bone, as well as glucose metabolism expression differences were assessed across the three groups. Results: The cortical bone thickness of the mandibles in the artificial light at night group [(0.196±0.017) mm] was significantly less than that in the control group [ (0.228±0.007) mm] (P=0.029). The bone volume fraction of the condylar ossification center in the artificial light at night group [(36.90±1.09) %] was significantly lower than that in the normal light group [(54.24±1.49) %] (P<0.001). The length of the mandible in the artificial light at night group [(10.86±0.17) mm] was significantly shorter than that in the normal light group [(11.41±0.32) mm] (P=0.032). RT-qPCR results indicated that the expressions of osteogenic-related genes alkaline phosphatase, liver/bone/kidney (Alpl), osteocalcin (Ocn), Runt-related transcription factor 2 (Runx2), and osterix (Osx) in the cortical bone and condylar ossification center of mice in the artificial light at night group were significantly lower than those in the normal light group (all P<0.05). The expression of metabolism-related genes protein kinase, AMP activated alpha 1 (Prkaa1), V-type proton ATPase subunit d 1 (Atp6v0d1), and cytochrome C oxidase subunit Ⅳ isoform 1 (Cox4i1) in the cortical bone and condylar ossification center of mice in the artificial light at night group were also significantly reduced compared to normal mice (all P<0.01). The serum melatonin concentration peaked 8 hours after lights off in the normal light group, whereas the artificial light at night group exhibited a significantly reduced nocturnal serum melatonin concentration with no apparent peak compared to the normal light group. Micro-CT results demonstrated that after artificial light at night group mice received timed melatonin supplementation daily, the thickness of cortical bone, the bone volume fraction of the condylar ossification center, and the length of the mandible were all significantly higher than those in the artificial light at night group (all P<0.05). Histological staining results indicated that the cortical bone structure of the mandibles in the melatonin supplementation group was more organized than that of the artificial light at night group, with higher brain and muscle ARNT-like 1 (BMAL1) expression (P=0.003). RT-qPCR results further showed that the expression levels of Prkaa1, Atp6v0d1, and Cox4i1 in the cortical bone and condylar ossification center significantly increased in the melatonin supplementation group compared to the artificial light at night group (all P<0.05), but still significantly lower than those in the normal light group (all P<0.05). Additionally, the RT-qPCR results further revealed that the expression levels of osteogenic differentiation-related genes Alpl, Ocn, and Runx2 in the cortical bone and condylar ossification center of the melatonin supplementation group were significantly higher than those in the artificial light at night group (all P<0.01). Western blotting analysis indicated that the expression levels of glucose metabolism and osteogenic-related proteins RUNX2, OSX, ATP6V0D1, and COX Ⅳ, along with the phosphorylation levels of AMPKα1/α2, were significantly higher in the melatonin supplementation group compared to the artificial light at night group (all P<0.01). Conclusions: Artificial light at night can inhibit melatonin secretion in mice, reduce glucose metabolism in mandibular tissues, and affect both intramembranous and chondrogenic ossification activities, ultimately leading to inadequate mandibular development.

Incidental Detection of Choroid Plexus Metastasis From Neuroblastoma Demonstrated by 68Ga-DOTATATE PET/CT.

An 8-year-old girl with refractory high-risk neuroblastoma underwent 68Ga-DOTATATE PET/CT to evaluate the feasibility of potential 177Lu-DOTATATE therapy. The scan showed multiple foci of abnormal 68Ga-DOTATATE accumulation in the bone region, indicating the presence of bone metastases. Unexpectedly, an abnormal tracer uptake was noted in the left lateral ventricle area. The contrast-enhanced brain MRI showed obvious enhancement of this lesion, suggesting the diagnosis of choroid plexus metastasis. Our case shows that 68Ga-DOTATATE PET/CT might be useful in diagnosing choroid plexus metastasis.

Are we underestimating pathological fracture risk in malignant bone lesions of the proximal humerus?

This study is aimed at evaluating the distribution of metastatic bone disease (MBD), with a particular focus on the humerus, and its association with pathological fractures. Factors for contributing to the underestimation of fracture risk were assessed, including their impact on surgical management. We retrospectively reviewed patient records of patients undergoing surgical treatment for MBD at our institution between 2005 and 2023. The analysis included factors such as medical history, tumour type, metastatic status, surgical method, lesion location, and imaging. The images of local and staging studies (CT chest/abdomen/pelvis, CT skeleton body, bone scan, PET/CT) were reviewed by two observers. Group comparisons were made based on lesion localisation. The two most affected bone regions were the proximal femur (39.4%), followed by the proximal humerus (13.5%). Lesions of the proximal humerus were significantly more likely to be associated with pathological fractures compared to those of the proximal femur and other localisations (p < 0.01). Identified potential causes include less frequent depiction of the proximal humerus during staging (29% vs. 79% and 51%; p < 0.01) and overall lower Mirel's scores despite the number of fractures (8 vs. 10 and 9; p < 0.01). Metastatic bone disease (MBD) in the proximal humerus is less frequently captured in current staging imaging, particularly CT chest/abdomen/pelvis. Additionally, fracture prediction using Mirel's scoring often underestimates the actual risk. Staging investigations should include this region more comprehensively, and even when correctly imaged, better tools are needed to evaluate bone metastases effectively.

DEK::AFF2 Squamous Cell Carcinomas of the Sinonasal Region and Temporal Bone Diagnosed After Recurrences: A Report of Two Patients.

DEK::AFF2 squamous cell carcinoma is a recently recognized entity characterized by a non-viral-related non-keratinizing squamous cell carcinoma with chromosomal rearrangement between DEK on 6p22.3 and AFF2 on Xq28. This neoplasm is associated with an aggressive clinical behavior, particularly regarding local recurrences and distant metastases even with its deceptively bland histomorphology. In this article, we report on 2 patients with DEK::AFF2 squamous cell carcinomas, which were only diagnosed at the time of recurrence. Patient #1 was originally misdiagnosed with inverted papilloma. This occurred 3 years previously, and at second presentation the tumor was recurrent in the nasal cavity and paranasal sinuses. Patient #2 was identified at second recurrence of a "nasopharyngeal carcinoma," initially diagnosed in the nasopharynx 5 years earlier, with a subsequent recurrence in the middle ear 2 years later, involving the mastoid process. The immunophenotypic and molecular work-up, as well as the management of these patients, are discussed. In our review of the English-language literature on DEK::AFF2 squamous cell carcinomas, we identified 41 patients, including our 2 patients. Of these, 26 had information on their clinical course. Sixty-nine percent of patients reported a history of locoregional recurrence, and 19% reported a history of distant metastases, with an average follow-up duration of 36 months after multimodality therapies. Given our improved understanding of DEK::AFF2 squamous cell carcinoma as an aggressive tumor, it is crucial to differentiate this neoplasm from other potential histomorphologic mimickers to ensure early and accurate diagnosis.

Linear regression analysis for complete blood count parameters during radiotherapy.

This study aimed to evaluate the correlations between complete blood count (CBC) during radiotherapy and patient and treatment factors. Data of cancer patients, including age, sex, concurrent chemotherapy (CCRT), radiotherapy dose (equivalent dose in 2‑Gy fractions with an alpha/beta value of 10 Gy, EQD2Gy10), radiotherapy location, and baseline CBC were collected. Linear regression was used to determine results during radiation. Validation data comprised 20% of the whole cohort. Atotal of 496 radiotherapy courses and 1884 weekly CBC results during treatment were analyzed. Baseline hemoglobin (Hb) was positively associated with subsequent Hb. Each 1 g/dL increase in baseline Hb predicted a0.73 g/dL increase in Hb during treatment (95% confidence interval [CI] 0.7-0.76). Male sex was associated with a0.16 g/dL higher Hb (95% CI 0.04-0.29), while female sex showed the opposite trend. CCRT was associated with a0.18 g/dL reduction in Hb (95% CI -0.33 to -0.03). Radiotherapy to the pelvis, bone, and head and neck regions resulted in Hb reductions of 0.18, 0.34, and 0.94 g/dL, respectively (95% CI -0.33 to -0.03, -0.53 to -0.15, and -1.26 to -0.62, respectively), while brain irradiation increased Hb by 0.22 g/dL (95% CI 0.05-0.38). Age, cumulative dose, and thoracic irradiation did not show asignificant correlation with Hb changes. Adjusted R‑squared for the development and validation data were 0.6 and 0.71 for Hb, 0.42 and 0.11 for white blood cell count, 0.36 and 0.32 for neutrophils, 0.42 and 0.06 for absolute neutrophil count, and 0.43 and 0.36 for platelets, respectively. Hb levels during radiotherapy could be explained using linear regression, although they did not negatively correlate with cumulative dose.

Morphological patterns of the European bison (Bison bonasus) skull

This study aimed to investigate the effects of environmental factors, sexual selection, and genetic variation on skull morphology by examining the skull structure of the European bison, a species at risk of extinction, and comparing it to other bovid species. The skull of the European bison was significantly bigger than that of other species of the tribe Bovini, and the results revealed considerable morphological differences in skull shape compared to other Bovini samples. The bison skull exhibited a broader shape in the frontal region and a more laterally oriented cornual process. The frontal bone also significantly influenced skull shape variation within the European bison subspecies. Also, the findings indicated that cornual processes size significantly affected skull shape. Male Bison had larger skulls and more developed cornual ridges, and these morphological changes in the frontal region are thought to have also influenced the nuchal region, maxillary region, and facial bones. Furthermore, the differences in skull size observed between the Lowland-Pszczyna and Lowland-Białowieża lines, which share a closer origin than the Lowland-Carpathian lines, may reflect environmental and genetic adaptations over time. This research provides a reference point for future studies on the ecological and evolutionary factors influencing bison skull variations, with significant implications for the conservation of this species.

The "Outline Sign": Thin Hyperenhancing Perimeter as an MR Imaging Feature of Meningioma. A Useful Tool in the Temporal Bone Region for Differentiating Meningiomas from Schwannomas and Paragangliomas.

This study investigates the practicality and utility of the "outline sign," which refers to the thin curvilinear hyperenhancing line that may be seen along the margin of a meningioma on a spin-echo postcontrast T1-weighted image. For cases in which the differential diagnosis may include other tumors, visualization of the outline sign may help to increase the diagnostic confidence for a meningioma. Therefore, in the temporal bone region such as the cerebellopontine angle or jugular foramen, where differential considerations may include a schwannoma or paraganglioma, we additionally investigated whether the outline sign may be observed in these nonmeningioma lesions. A total of 39 clinical MRIs of meningiomas, schwannomas, and paragangliomas with confirmed histopathologic data were studied retrospectively. Two experienced head and neck radiologists independently assessed for the presence or absence of an outline sign and subsequently formed a consensus opinion while blinded to patient information and histopathologic data. Interreader reliability was assessed by Cohen κ statistics. Simple bivariate comparisons were performed on the consensus opinions to assess for statistical differences in presence of the sign in meningiomas versus schwannomas and paragangliomas. Sensitivity, specificity, and accuracy of the sign with respect to identifying an underlying meningioma were calculated. Both readers displayed identical opinions in assessment of the outline sign in 34 of the 39 cases (87%), including 13 of the 14 meningiomas (93%), with substantial agreement (Cohen κ of 0.74). The outline sign was present in 12 of 14 meningiomas (86%), which was significantly greater in frequency compared with schwannomas (3 of 22, 14%) and paragangliomas (1 of 3, 33%). The outline sign demonstrated high sensitivity (86%), specificity (84%), and accuracy (85%) in identifying an underlying meningioma. The outline sign can serve as a useful tool for diagnosing meningiomas. It may help distinguish meningiomas from other enhancing tumors, for example schwannomas and paragangliomas in the temporal bone region.

Deep learning and genome-wide association meta-analyses of bone marrow adiposity in the UK Biobank

Bone marrow adipose tissue is a distinct adipose subtype comprising more than 10% of fat mass in healthy humans. However, the functions and pathophysiological correlates of this tissue are unclear, and its genetic determinants remain unknown. Here, we use deep learning to measure bone marrow adiposity in the femoral head, total hip, femoral diaphysis, and spine from MRI scans of approximately 47,000 UK Biobank participants, including over 41,000 white and over 6300 non-white participants. We then establish the heritability and genome-wide significant associations for bone marrow adiposity at each site. Our meta-GWAS in the white population finds 67, 147, 134, and 174 independent significant single nucleotide polymorphisms, which map to 54, 90, 43, and 100 genes for the femoral head, total hip, femoral diaphysis, and spine, respectively. Transcriptome-wide association studies, colocalization analyses, and sex-stratified meta-GWASes in the white participants further resolve functional and sex-specific genes associated with bone marrow adiposity at each site. Finally, we perform a multi-ancestry meta-GWAS to identify genes associated with bone marrow adiposity across the different bone regions and across ancestry groups. Our findings provide insights into BMAT formation and function and provide a basis to study the impact of BMAT on human health and disease.

Preoperative Frontal and Parietal Bone Thickness Assessment to Predict Blood Loss and Transfusion During Extended Suturectomy for Isolated Sagittal Craniosynostosis.

To predict the morbidity of sagittal suturectomy using preoperative computer tomographic measurement of frontal and parietal bone thickness in osteotomy sites. Retrospective analysis. Tertiary children's hospital. Fifty infants with nonsyndromic, isolated sagittal craniosynostosis who underwent extended sagittal suturectomy from 2015-2022. Mean thickness of the frontal and parietal bone in regions of osteotomies were determined for each patient from preoperative CT images obtained within 30 days prior to suturectomy. The relationship between bone thickness (mm) and estimated blood loss (mL) was evaluated using Spearman's correlation and a multivariable model that adjusted for patient weight and surgery duration. The association between bone thickness and perioperative blood transfusion was evaluated using a multivariable logistic model controlling for patient weight and surgery duration. Estimated blood loss, perioperative blood transfusion. Frontal and parietal bone thickness in the region of osteotomies were positively correlated with estimated blood loss (p < 0.01). After adjusting for patient weight and duration of operation, both parietal and frontal bone thickness were associated with intraoperative blood loss (R2 = 0.292, p = 0.002 and R2 = 0.216, p = 0.026). Thicker frontal and parietal bone in the line of osteotomies resulted in significantly higher odds of blood transfusion. Bone thickness in the line of parietal osteotomies was 76% accurate at identifying patients who would require blood transfusion (p = 0.004). Frontal and parietal bone thickness in the line of osteotomies is associated with blood loss and perioperative blood transfusion for sagittal suturectomy operations.

Bone mass distribution of 892 distal tibiae and implications for the treatment of medial malleolar fractures.

The medial malleolus is involved in up to 50 % of ankle fractures. When surgery is required, a thorough understanding of bone mass distribution within the distal tibia is crucial for selecting and positioning screws to ensure stable fixation. Despite its clinical significance, data on the bone mass distribution in the distal tibia remains limited. A total of 892 anonymized computed tomography data sets were analyzed to assess bone mass distribution in the distal tibia. Patients were categorized based on age, sex and stratified into those with normal (Hounsfield units (HU) ≥ 122) and reduced (HU < 122) bone density. Utilizing color-coded thermal maps, bone density and bone mass distribution in the distal tibia was visualized. Subsequently, simulation of potential screw trajectories for medial malleolar fracture treatment were conducted and bone density along those trajectories measured. Patients exhibiting reduced bone density (n = 442) were significantly older (69 (IQR 60-78)) than those with regular bone density (n = 450) aged (62 (IQR 47-72)) and more often female (p < 0.0001). The highest bone density was located within the proximal one centimeter from the distal tibial articular surface. Another region of dense bone was found at the transition from the distal tibia to the medial malleolus. Bone density was lowest at the distal tibial shaft region beginning at around 30 mm (in females) and 33 mm (in males) from the tip of the medial malleolus. Our data highlights the areas with the highest bone density in the distal tibia. When fixing medial malleolar fractures with unicortical partially threaded screws, this data suggests that screws with a length between 36 and 41 mm should be used at the anterior colliculus and intercollicular. However, regardless of our findings, fracture morphology must be considered, and the AO principles of fracture fixation should be adhered to. III.

A finite element analysis to assess tibial bone fracture in malleolar regions following total ankle replacement: Influences of implant designs and implant-bone interfacial conditions.

Tibial bone fractures in the malleolar regions are a major concern during the early postoperative period of total ankle replacement (TAR), affecting patient outcomes such as stability and recovery. Design, placement, and anatomic misalignment of implant components can contribute to malleolar fractures. The aim of this study is to understand the influence of implant design features, including keel, peg, stem, and bar type design, and bone-implant interfacial conditions on malleolar fracture following TAR. Three-dimensional finite element (FE) models were generated for the intact and implanted tibia bone using computer tomography (CT) scan data. In the present study, both bonded (fully osseointegration) and debonded (non-osseointegration) implant-bone interface conditions were considered. The proximal part of the tibia was fixed. Finite element models of the intact and implanted tibia were solved for three distinct loading situations that correspond to three ankle positions throughout the gait cycle (GC). The influences of implant design and implant-bone interface conditions on malleolar fracture were examined by evaluating stress distribution in tibia bone post-implantation. Finite element (FE) analysis revealed that for the medial region, the tibia bone stress elevated to 10 MPa for the medial keel type design, indicating a possible fracture along the medial region. The risk of a medial malleolar fracture is highest for the medial keel type implant design compared to other designs. The bars, central keel, and stem type TAR implant designs also elevate stress on both the medial and lateral regions of the tibia bone. In the case of fully osseointegrated implant-bone interface conditions, the stress is slightly higher than in the case of non-osseointegrated implant-bone interfacial conditions. The study highlights the potential influence of specific implant designs on malleolar fracture. The current findings are crucial for designing new implants to mitigate tibial bone fracture risks and improve TAR outcomes.

Bone quality analysis of the mandible in alcoholic liver cirrhosis: Anatomical, microstructural, and microhardness evaluation.

Alcoholic bone disease has been recognized in contemporary literature as a systemic effect of chronic ethanol consumption. However, evidence about the specific influence of alcoholic liver cirrhosis (ALC) on mandible bone quality is scarce. The aim of this study was to explore microstructural, compositional, cellular, and mechanical properties of the mandible in ALC individuals compared with a healthy control group. Mandible bone cores of mаle individuаls with ALC (n = 6; age: 70.8 ± 2.5 yeаrs) and age-matched healthy controls (n = 11; age: 71.5 ± 3.8 yeаrs) were obtаined postmortem during аutopsy from the edentulous аlveolаr bone in the mandibular first molаr region аnd the mаndibulаr аngulus region of each individual. Micro-computed tomogrаphy wаs used to аssess bone microstructure. Analyses based on quаntitаtive bаckscаttered electron microscopy included the characterization of osteon morphology, osteocyte lаcunаr properties, and bone mаtrix minerаlizаtion. Composition of bone minerаl аnd collаgen phаses was assessed by Rаmаn spectroscopy. Histomorphometry wаs used to determine cellulаr аnd tissue chаrаcteristics of bone specimens. Vickers microhardness test was used to evaluate cortical bone mechanical properties. The ALC group showed higher closed cortical porosity (volume of pores thаt do not communicаte with the sаmple surfаce) (p = 0.003) and smaller lacunar area in the trabecular bone of the molar region (p = 0.002) compared with the Control group. The trabecular bone of the angulus region showed lower osteoclast number (p = 0.032) in the ALC group. There were higher carbonate content in the buccal cortex of the molar region (p = 0.008) and lower calcium content in the trabecular bone of the angulus region (p = 0.042) in the ALC group. The cortical bone showed inferior mechanical properties in the ALC cortical bony sites (p < 0.001), except for the buccal cortex of the molar region (p = 0.063). There was no significant difference in cortical thickness between the groups. Bone quality is differentially altered in ALC in two bony sites and compartments of the mandible, which leads to impaired mechanical properties. Altered mandible bone tissue characteristics in patients with ALC should be considered by dental medicine professionals prior to oral interventions in these patients. Knowledge about mandible bone quality alterations in ALC is valuable for determining diagnosis, treatment plan, indications for oral rehabilitation procedures, and follow-up procedures for this group of patients.

Diagnostic Performance of Imaging Methods in Predicting Lung Cancer Metastases.

This study aimed to investigate the possibility of distant organ metastasis using an algorithm developed to evaluate the morphology and localization of lung masses. Patients diagnosed with lung cancer between 2016 and 2023 were included. The lesion's morphological characteristics, proximity to important structures, and maximum standardized uptake value were recorded. Six common metastatic sites were identified: the contralateral lung, liver, brain, adrenal glands, bone, and other regions. The relationship between the characteristics of the mass and the metastatic location was investigated. A total of 383 patients (260 men, 68%) with malignant lung lesions with a mean ± SD age of 65.50 ± 12.34 years (range: 36-74 years) were included in the study. Among them, 242 were diagnosed with primary lung cancer, and 106 (43.8%) exhibited metastases to other organs with primary lung tumors. Distant organ metastases were most frequently detected in the bones (n = 45, 42.5%) and were more frequent in male patients and lesions adjacent to the ribs and bronchi, those involving mediastinal lymph nodes, irregular contours, and maximum standardized uptake values above 11.15 ± 5.67 (mean ± SD). Evaluating radiological imaging of malignant lesions in patients with lung cancer using an algorithm that considers morphological and neighborhood characteristics can provide predictive information regarding the possibility of metastasis of malignant lung lesions and the metastatic location.

A Biodegradable Magnesium Alloy Promotes Subperiosteal Osteogenesis Via Interleukin-10-Dependent Macrophage Immunomodulation

In situ bone regeneration and vertical bone augmentation have been huge problems in clinical, always imposing a significant economic burden and causing patient suffering. Herein, MgZnYNd magnesium alloy rod implantation in mice femur results in substantial subperiosteal new bone formation, with osteoimmunomodulation playing a pivotal role. Abundant macrophages are attracted to the subperiosteal new bone region and proved to be the most important regulation cells for bone regeneration. Periosteum stripping, macrophage depletion, and interleukin-10 (IL-10) blockage effectively diminish the MgZnYNd alloy-induced subperiosteal osteogenesis. Mechanistically, the degradation products of MgZnYNd alloy promote M2 macrophage polarization and the secretion of anti-inflammatory cytokine IL-10, which enhances periosteum-derived stem cells (PDSCs) osteogenesis through the JAK1-STAT3 pathway. An anti-IL-10 neutralizing antibody or STAT3 inhibitor significantly inhibits M2 macrophage-mediated osteogenic differentiation of PDSCs. Transcriptomic and proteomics reveal that periostin is the core regulator of PDSCs osteogenesis differentiation. Furthermore, a novel clinical translation application of Mg-induced subperiosteal osteogenesis is developed, demonstrating its ability to preserve the height and width of the alveolar crest in rats and rabbits following tooth extraction. Collectively, these findings unveil a previously undefined role for Mg alloy-induced subperiosteal osteogenesis via macrophage-mediated osteoimmunomodulation, suggesting the therapeutic potential of magnesium alloy in bone regeneration and bone augmentation.

Facemask application with fixed orthodontic appliances: 3-dimensional finite element stress analysis.

Facemask(FM) is an orthopedic appliance with extraoral and intraoral anchoring units used in treatment of maxillary retrognathia. Aim of this study was to assess effects of tooth-supported FM application via fixed orthodontic appliances on craniofacial structures with finite element stress analysis. A model was constructed on maxillary teeth with Roth brackets (0.018″slot), 0.018″x0.025″ stainless steel archwire, and crimpable hooks placed distal to upper lateral incisors. The scenario included application of FM with 350 g force, forming 30° angle with occlusal plane. Stress distributions and displacements on craniofacial bones, sutures, intraoral anchoring unit and maxillary teeth were evaluated. High stress distributions were observed in anterior maxilla, pterygomaxillary region, zygomatic arch, and frontal process of zygomatic bone. Zygomaticotemporal, zygomaticofrontal, pterygomaxillary sutures and intraoral anchoring unit showed high stress distributions too. Stresses along maxillary teeth were not uniform, declaring increased stress distributions at the anterior region, but tended to decrease to posterior. Forward displacement was observed in all landmarks and counterclockwise rotation of maxilla and dentition were observed vertically. Narrowing in maxillary dental arch was observed. Tooth-supported FM application over the brackets created stresses on craniofacial bones and sutures. Increased stress distribution were evident at the anterior maxillary region close to the force application points. Displacements were observed in all directions, drawing special attention to transversal narrowing and counterclockwise rotation of maxilla. In this respect, clinical attention should be made during FM application anchored from fixed braces, with either using rigid archwires or supporting mechanics with transpalatal arches.

An unusual case of primary pulmonary synovial sarcoma

BackgroundAn extremely rare intrathoracic tumour that typically affects young adults is primary pulmonary synovial sarcoma. It manifests as a big intrathoracic mass without involvement of the bone or mediastinal region. Tumour biopsy, immunostaining and histologic analysis can assist in determining the kind of tumour.Case presentationWe present a case of a 25-year-old male with complaints of breathlessness and chest pain for a month. On radiological imaging, he was found to have mass in upper and middle zones of right hemithorax. For confirmation of diagnosis, the patient underwent ultrasound-guided biopsy of the lesion and histopathologhical examination (HPE) of the lesion. The histopathological features were suggestive of a rare type of lung malignancy. For further diagnosis regarding type of malignancy, immunohistochemical staining of the lesion was done with the help of with specific immunological markers, which confirmed the diagnosis of monophasic pulmonary sarcoma. On PET (positron emission tomography) CT (computed tomography) scan, there were no features suggestive of distant metastasis especially in extremities which confirmed the diagnosis of primary pulmonary synovial sarcoma. Patient was started on chemotherapy regimen of ifosfamide and doxorubicin after oncologist’s opinion but was lost to follow up after 3rd cycle of chemotherapy.ConclusionsPrimary pulmonary synovial sarcoma is an extremely uncommon tumour in young adults as lung metastases from other sources mainly extremities are more common. Diagnosis of such rare tumour requires histopathological examination along with immunohistochemical staining of the lung lesions. A multimodal strategy of treatment involving resection, chemotherapy and radiation is used for the treatment of such tumours.

Automatic knee osteoarthritis severity grading based on X-ray images using a hierarchical classification method

BackgroundThis study aims to develop a hierarchical classification method to automatically assess the severity of knee osteoarthritis (KOA).MethodsThis retrospective study recruited 4074 patients. Clinical diagnostic indicators and clinical diagnostic processes were applied to develop a hierarchical classification method that involved four sub-task classifications. These four sub-task classifications were the classification of Kellgren-Lawrence (KL) grade 0–2 and KL grade 3–4, KL grade 3 and KL grade 4, KL grade 0 and KL grade 1–2, and KL grade 1 and KL grade 2, respectively. To extract the features of clinical diagnostic indicators, four U-Net models were first used to segment the total joint space (TJS), the lateral joint space (LJS), the medial joint space (MJS), and osteophytes, respectively. Based on the segmentation result of TJS, the region of knee subchondral bone was generated. Then, geometric features were extracted based on segmentation results of the LJS, MJS, TJS, and osteophytes, while radiomic features were extracted from the knee subchondral bone. Finally, the geometric features, radiomic features, and combination of geometric features and radiomic features were used to construct the geometric model, radiomic model, and combined model in KL grading, respectively. A strict decision strategy was used to evaluate the performance of the hierarchical classification method in all X-ray images of testing cohort.ResultsThe U-Net models achieved relatively satisfying performances in the segmentation of the TJS, the LJS, the MJS, and the osteophytes with the dice similarity coefficient of 0.88, 0.86, 0.88, and 0.64 respectively. The combined models achieved the best performance in KL grading. The accuracy of combined models was 98.50%, 81.65%, 82.07%, and 74.10% in the classification of KL grade 0–2 and KL grade 3–4, KL grade 3 and KL grade 4, KL grade 0 and KL grade 1–2, and KL grade 1 and KL grade 2, respectively. For all X-ray images of the testing cohort, the accuracy of the hierarchical classification method was 65.98%.ConclusionThe hierarchical classification method developed in the current study is a feasible approach to assess the severity of KOA.

Stress transfer, stress shielding, and micro-movement analysis in the implanted femoral bone region with various hip implant stem materials: A finite element approach

This study analyzed stress distribution, stress shielding, and bone-implant micro-movement in different zones of implanted femur bone with hip implant stem composed of Inconel 718, 316 Stainless Steel, Ti6Al7Nb, Ti6Al4V, Ti-12Mo-6Zr-2Fe (TMZF), and Ti-33.6Nb-4Sn (TNS). A 3D model of a well-known hip implant “Summit” was placed in an adult femur bone, and walking, standing, and sitting load instances were simulated as loading conditions using a finite element model (FEM). Increasing hip implant material hardness reduces stress transmission in Gruen zones 1, 2, 5, 6, and 7 of the femur bone but increases it in Gruen zone 3. It also enhances stress holding in the implant body and elevates the Stress Shielding index (SSI) at seven Gruen zones for each load case. TMZF and TNS hip implants in Gruen regions 5 and 7 have negative SSI values under specific load situations. At Gruen zone 3, the SSI value for implanted femur bone increases with hip implant stem material hardness and SSI values variation in implanted femur bone for hip implants of different materials at each loading scenario is within 10 %. However, SSI values do not follow any pattern at Gruen zone 4. Less stiff implants demonstrate increased micro-movement in bone-implant contact zones 1 and 2 due to higher stress transfer. Greater stiffness (Inconel 718) caused increased micro-movement in zone 3. The overall micro-movement (Average and Highest) found an incremental trend for hip implants with higher stiffer to lower materials. The lowest stiff material (TNS) is still in the range of appropriate micro-movement for promoting osteointegration. This study indicates TNS as a superior hip implant stem material due to its enhanced stress distribution, reduced SSI in most Gruen zones on implanted femurs, and acceptable micro-movement over the implant-bone area of contact. Further research is required to minimize SSI, particularly in Gruen zone 3, when using TNS hip implants in implanted femurs.