INTRODUCTION: Fibroblast growth factor 20 (Fgf20), a member of the Fgf9 subfamily, was identified as an important regulator of bone differentiation and homeostasis processes. However, the role of Fgf20 in bone physiology has not been approached yet. Here we present a comprehensive bone phenotype analysis of mice with functional ablation of Fgf20. METHODS: The study conducts an extensive analysis of Fgf20 knockout mice compared to controls, incorporating microCT scanning, volumetric analysis, Fgf9 subfamily expression and stimulation experiment and histological evaluation. RESULTS: The bone phenotype could be detected especially in the area of​ the lumbar and caudal part of the spine and in fingers. Regarding the spine, Fgf20-/- mice exhibited adhesions of the transverse process of the sixth lumbar vertebra to the pelvis as well as malformations in the distal part of their tails. Preaxial polydactyly and polysyndactyly in varying degrees of severity were also detected. High resolution microCT analysis of distal femurs and the fourth lumbar vertebra showed significant differences in structure and mineralization in both cortical and trabecular bone. These findings were histologically validated and may be associated with the expression of Fgf20 in chondrocytes and their progenitors. Moreover, histological sections demonstrated increased bone tissue formation, disruption of Fgf20-/- femur cartilage, and cellular-level alterations, particularly in osteoclasts. We also observed molar dysmorphology, including root taurodontism, and described variations in mineralization and dentin thickness. DISCUSSION: Our analysis provides evidence that Fgf20, together with other members of the Fgf9 subfamily, plays a crucial regulatory role in skeletal development and bone homeostasis.

• MeSH
• Phenotype MeSH
• Fibroblast Growth Factors * metabolism   genetics   MeSH
• Calcification, Physiologic MeSH
• Bone and Bones metabolism   pathology   diagnostic imaging   abnormalities   MeSH
• Mice, Inbred C57BL MeSH
• Mice, Knockout * MeSH
• Mice MeSH
• Osteogenesis MeSH
• X-Ray Microtomography MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: The spatially varying mechanical properties in finite element models of bone are most often derived from bone density data obtained via quantitative computed tomography. The key step is to accurately and efficiently map the density given in voxels to the finite element mesh. METHODS: The density projection is first formulated in least-squares terms and then discretized using a continuous and discontinuous variant of the finite element method. Both discretization variants are compared with the nodal and element approaches known from the literature. FINDINGS: In terms of accuracy in the L2 norm, energy distance and efficiency, the discontinuous zero-order variant appears to be the most advantageous. The proposed variant sufficiently preserves the spectrum of density at the edges, while keeping computational cost low. INTERPRETATION: The continuous finite element method is analogous to the nodal formulation in the literature, while the discontinuous finite element method is analogous to the element formulation. The two variants differ in terms of implementation, computational cost and ability to preserve the density spectrum. These differences cannot be described and measured by known indirect methods from the literature.

• MeSH
• Finite Element Analysis MeSH
• Bone and Bones * diagnostic imaging   MeSH
• Bone Density MeSH
• Humans MeSH
• Tomography, X-Ray Computed * methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Parathyroid hormone (PTH) increases the release of serum calcium through osteoclasts, which leads to bone resorption. Primary, PTH stimulates osteoblasts leading to increase RANKL (receptor activator for nuclear factor kappa-B ligand) expression and thus differentiation of osteoclasts. In kidneys, PTH increases calcium and decrease phosphate reabsorption. In kidneys, PTH stimulates 1alpha-hydroxylase to synthesize active vitamin D. Primary hyperparathyroidism (PHPT) is characterized by skeletal or renal complications. Nowadays, the classical form of PHPT is less seen and asymptomatic or subclinical (oligo symptomatic) forms are more frequent. Previously, it was thought that cortical bone is preferably affected by PHPT and that predispose bones to fracture at sites with a higher amount of cortical bone. However, an increased risk of vertebral fractures has been found by most of the studies showing that also trabecular bone is affected. Bone Mass measurement (BMD) at all skeletal sites is advised, but another specific tool for fracture assessment is needed. Trabecular bone score (TBS), an indirect measure of trabecular bone, maybe a useful method to estimate fracture risk. TBS is associated with vertebral fractures in PHPT regardless of BMD, age, BMI and gender. Furthermore, there is an association between TBS and high resolution peripheral quantitative computed tomography (HR-pQCT) parameters in the trabecular and cortical compartment. However, studies considering the effect of PHPT treatment on TBS are more conflicting. Secondary hyperparathyroidism caused by vitamin D deficiency was associated with impaired bone microarchitecture in all age categories, as measured by TBS and Hr-pQCT with further improvement after treatment with vitamin D.

• MeSH
• Bone and Bones diagnostic imaging   physiology   MeSH
• Bone Density MeSH
• Humans MeSH
• Parathyroid Hormone physiology   MeSH
• Tomography, X-Ray Computed MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

• Keywords
• Masqueletova technika,
• MeSH
• Splints MeSH
• External Fixators classification   MeSH
• Fractures, Bone * surgery   history   diagnostic imaging   therapy   MeSH
• Ilizarov Technique MeSH
• Fracture Fixation, Intramedullary methods   instrumentation   MeSH
• Bone and Bones surgery   diagnostic imaging   MeSH
• Humans MeSH
• Orthopedic Procedures * history   methods   MeSH
• Fracture Fixation, Internal classification   MeSH
• Plastic Surgery Procedures classification   MeSH
• Check Tag
• Humans MeSH

BACKGROUND: Beyond its structural role in the skeleton, the extracellular matrix (ECM), particularly basement membrane proteins, facilitates communication with intracellular signaling pathways and cell to cell interactions to control differentiation, proliferation, migration and survival. Alterations in extracellular proteins cause a number of skeletal disorders, yet the consequences of an abnormal ECM on cellular communication remains less well understood METHODS: Clinical and radiographic examinations defined the phenotype in this unappreciated bent bone skeletal disorder. Exome analysis identified the genetic alteration, confirmed by Sanger sequencing. Quantitative PCR, western blot analyses, immunohistochemistry, luciferase assay for WNT signaling were employed to determine RNA, proteins levels and localization, and dissect out the underlying cell signaling abnormalities.  Migration and wound healing assays examined cell migration properties. FINDINGS: This bent bone dysplasia resulted from biallelic mutations in LAMA5, the gene encoding the alpha-5 laminin basement membrane protein. This finding uncovered a mechanism of disease driven by ECM-cell interactions between alpha-5-containing laminins, and integrin-mediated focal adhesion signaling, particularly in cartilage. Loss of LAMA5 altered β1 integrin signaling through the non-canonical kinase PYK2 and the skeletal enriched SRC kinase, FYN. Loss of LAMA5 negatively impacted the actin cytoskeleton, vinculin localization, and WNT signaling. INTERPRETATION: This newly described mechanism revealed a LAMA5-β1 Integrin-PYK2-FYN focal adhesion complex that regulates skeletogenesis, impacted WNT signaling and, when dysregulated, produced a distinct skeletal disorder. FUNDING: Supported by NIH awards R01 AR066124, R01 DE019567, R01 HD070394, and U54HG006493, and Czech Republic grants INTER-ACTION LTAUSA19030, V18-08-00567 and GA19-20123S.

• MeSH
• Alleles * MeSH
• Cell Adhesion genetics   MeSH
• Chondrocytes metabolism   MeSH
• Phenotype MeSH
• Focal Adhesion Kinase 2 genetics   metabolism   MeSH
• Genetic Predisposition to Disease MeSH
• Genetic Association Studies MeSH
• Bone and Bones abnormalities   diagnostic imaging   MeSH
• Laminin genetics   metabolism   MeSH
• Humans MeSH
• Mutation * MeSH
• DNA Mutational Analysis MeSH
• Wnt Signaling Pathway MeSH
• Signal Transduction * MeSH
• src-Family Kinases metabolism   MeSH
• Bone Diseases, Developmental diagnosis   etiology   metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Cíl: Prezentace náhodného nálezu kostního infarktu na scintigrafii skeletu indikované v rámci stagingu onkologického onemocnění. Kazuistika: 73letá pacientka byla odeslána na celotělovou scintigrafii skeletu k vyloučení generalizace karcinomu prsu. Vyšetření neprokázalo metastatický proces, ale odhalilo vysokou ložiskovou akumulaci radiofarmaka ve femuru a tibii v blízkosti levého kolenního kloubu. Diferenciálně diagnosticky byla zvažována osteomyelitida, fibrózní kostní dysplazie, ev. tumorózní postižení. Bylo doplněno cílené SPECT/low-dose CT, které scintigraficky prokázalo zvýšenou akumulaci radiofarmaka konturující dřeňovou dutinu v distální metadiafýze femuru a proximální tibii, v LDCT obraze byl v těchto partiích obou kostí tenký nepravidelný sklerotický lem dřeňové dutiny, dále na dorzální straně femuru zesílení kortikalis. Diferenciální diagnóza se tak rozšířila o kostní infarkt a aneuryzmatickou cystu. Anamnéza ve vztahu k levé dolní končetině byla negativní. Etiologie těchto kostních afekcí byla na základě našich vyšetření nejednoznačná, doporučili jsme dovyšetření. Na onkologem indikovaném plnohodnotném CT vykazovala léze znaky kostního infarktu. Závěr: Kazuistika potvrzuje důležitost provedení cíleného SPECT/CT podle nálezu na celotělových scanech a korelaci obrazu s jinými resp. radiologickými zobrazovacími metodami.

Aim: Presentation of an incidental finding on bone scan indicated within a staging of oncological disease. Case report: Case report: 73-year-old female patient was refered for a bone scan to exclude generalization of breast cancer. The examination did not reveal a metastatic proces but a high focal accumulation of a radiofarmaceutical in the femur and tibia near the left knee joint was visible. Osteomyelitis, fibrous bone dysplasia, or tumorous affection were considered at the differential diagnosis. Targeted SPECT/low-dose CT displayed increased accumulation of radiofarmaceutical at scintigraphic image, which contoured marrow cavity in distal metadiaphysis of the femur and proximal tibia. In addition, LDCT showed thickened corticalis of the dorsal part of the left femur. The differential diagnosis was thus extended by a bone infarction and aneurysmal bone cyst. The history connected with the left lower limb was negative. Etiology of these bone affections based on our examinations was ambiguous, we recommended targeted radiological investigation. At the oncologist-indicated CT, the lesions showed signs of a bone infarction. Conclusion: Our case report confirms the importance of performing targeted SPEC/CT according to findings on bone scans and correlation with other examinations possibly radiological imaging methods.

• Keywords
• kostní infarkt,
• MeSH
• Femur diagnostic imaging   pathology   MeSH
• Bone and Bones diagnostic imaging   pathology   MeSH
• Humans MeSH
• Breast Neoplasms MeSH
• Incidental Findings MeSH
• Osteonecrosis * diagnostic imaging   etiology   pathology   MeSH
• Aged MeSH
• Single Photon Emission Computed Tomography Computed Tomography methods   MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Case Reports MeSH

V České republice je ročně zjištěno několik set případů fyzického týrání dětí. Nejrizikovější skupinou jsou nejmladší děti. Týrání se může projevit celou škálou nálezů. Některé nálezy však mají vysokou specificitu pro týrání, zvláště pokud jsou odhaleny u kojenců. Mezi radiologická traumata s vysokou specificitou patří tzv. klasické metafyzární léze, zlomeniny žeber a poranění duodena. Vyšetřování týraných dětí je náročné, protože anamnéza bývá nespolehlivá, návštěva zdravotnického zařízení je odkládána, děti samy vzhledem k věku nemohou o podaném incidentu podat výpověď, a i při těžkém intrakraniálním nebo intraabdominálním poranění často zevní známky traumatu u dítěte zcela chybí. Zobrazovací metody mohou pomoci při odhalení traumatických změn skeletu, mozku a intraabdominálních orgánů, časovém odhadu jejich vzniku i diferenciální diagnostice. Aby byla jejich výtěžnost nejvyšší, je nutné dodržovat standardizované postupy, které vychází z medicíny založené na důkazech.

Several hundred children are physically abused annualy in the Czech Republic. Young age is the most important risk factor. Physical abuse can manifest in numerous ways. Some findings have high specificity for abuse, especially when present in infants. The radiology findings with high specificity for abuse include classic metaphyseal lesions, rib fractures and duodenal trauma. Investigating abused children is difficult because the history tends to be unreliable, children present to hospital after a significant time delay, and the children cannot provide a history themselves due to young age. Moreover, the children often show no visible signs of trauma even in cases of severe intracranial or intraabdominal injuries. Imaging methods are helpful in recognizing skeletal, intracranial, and intraabdominal injuries, assist in their dating and differential diagnosis. In order to yield maximum results from imaging methods, it is necessary to follow recommendations based on up-to date evidence-based medicine.

• Keywords
• kostní protokol,
• MeSH
• Fractures, Bone diagnostic imaging   MeSH
• Rib Fractures diagnostic imaging   MeSH
• Clinical Protocols MeSH
• Infant MeSH
• Bone and Bones diagnostic imaging   injuries   MeSH
• Craniocerebral Trauma diagnostic imaging   MeSH
• Humans MeSH
• Mandatory Reporting MeSH
• Tomography, X-Ray Computed MeSH
• Abdominal Injuries diagnostic imaging   MeSH
• Thoracic Injuries diagnosis   MeSH
• Liability, Legal MeSH
• Radiography methods   MeSH
• Wounds and Injuries * diagnostic imaging   MeSH
• Battered Child Syndrome diagnostic imaging   MeSH
• Child Abuse * diagnosis   legislation & jurisprudence   MeSH
• Check Tag
• Infant MeSH
• Humans MeSH

• MeSH
• Absorptiometry, Photon MeSH
• Amenorrhea * diagnostic imaging   complications   MeSH
• Fractures, Bone * diagnostic imaging   epidemiology   etiology   MeSH
• Bone and Bones * diagnostic imaging   MeSH
• Bone Density * physiology   MeSH
• Humans MeSH
• Anorexia Nervosa * diagnostic imaging   complications   MeSH
• Adolescent MeSH
• Young Adult MeSH
• Prevalence MeSH
• Athletes * MeSH
• Check Tag
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Female MeSH
• Publication type
• Overall MeSH

• MeSH
• Diabetes Mellitus, Type 1 * diagnosis   complications   MeSH
• Child MeSH
• Glycated Hemoglobin analysis   MeSH
• Bone and Bones diagnostic imaging   MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Musculoskeletal System diagnostic imaging   physiopathology   MeSH
• Osteoporosis MeSH
• Tomography, X-Ray Computed methods   MeSH
• Sex Factors MeSH
• Muscle Strength Dynamometer MeSH
• Muscle Strength MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH

• MeSH
• Radiotherapy, Adjuvant methods   standards   MeSH
• Biopsy MeSH
• Child MeSH
• Long-Term Care methods   standards   MeSH
• Adult MeSH
• Incidence MeSH
• Bone and Bones diagnostic imaging   pathology   surgery   MeSH
• Medical Oncology methods   standards   MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Bone Neoplasms diagnosis   epidemiology   pathology   therapy   MeSH
• Aftercare methods   standards   MeSH
• Neoadjuvant Therapy methods   standards   MeSH
• Survivorship MeSH
• Orthopedic Procedures methods   standards   MeSH
• Osteosarcoma diagnosis   epidemiology   pathology   therapy   MeSH
• Positron Emission Tomography Computed Tomography MeSH
• Antineoplastic Combined Chemotherapy Protocols standards   therapeutic use   MeSH
• Radionuclide Imaging MeSH
• Societies, Medical standards   MeSH
• Neoplasm Staging MeSH
• Self-Help Groups standards   MeSH
• Age Factors MeSH
• Treatment Outcome MeSH
• Patient Participation * MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Humans MeSH
• Publication type
• Journal Article MeSH
• Practice Guideline MeSH
• Geographicals
• Europe MeSH