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Hand Clinics Aug 2017Recent laboratory research has disclosed that carpal ligaments exhibit different kinetic behaviors depending on the direction and point of application of the forces... (Review)
Review
Recent laboratory research has disclosed that carpal ligaments exhibit different kinetic behaviors depending on the direction and point of application of the forces being applied to the wrist. The so-called helical antipronation ligaments are mostly active when the wrist is axially loaded, whereas the helical antisupination ligaments constrain supination torques to the distal row. This novel way of interpreting the function of the carpal ligaments may help in developing better strategies to treat carpal instabilities.
Topics: Carpal Bones; Humans; Joint Instability; Ligaments, Articular; Wrist; Wrist Joint
PubMed: 28673627
DOI: 10.1016/j.hcl.2017.04.007 -
BMC Musculoskeletal Disorders May 2022Hyperplasia of the hematopoietic bone marrow in the appendicular skeleton is common. In contrast, focal hematopoietic islands within the axial skeleton are a rare entity...
BACKGROUND
Hyperplasia of the hematopoietic bone marrow in the appendicular skeleton is common. In contrast, focal hematopoietic islands within the axial skeleton are a rare entity and can confuse with osteoblastic metastases. This study aimed to characterize typical MRI and CT findings of hematopoietic islands in distinction from osteoblastic metastases to help both radiologists and clinicians, on the one hand, not to overdiagnose this entity and, on the other hand, to decide on a reasonable work-up.
METHODS
We retrospectively analyzed the imaging findings of 14 hematopoietic islands of the axial skeleton in ten patients (nine females, median age = 65.5 years [range, 49-74]) who received both MRI and CT at initial diagnosis between 2006 and 2020. CT-guided biopsy was performed in five cases to confirm the diagnosis, while the other five patients received long-term MRI follow-up (median follow-up = 28 months [range, 6-96 months]). Diffusion-weighted imaging was available in three, chemical shift imaging respectively F- fluorodeoxyglucose PET/CT in two, and Technetium 99 m skeletal scintigraphy in one of the patients.
RESULTS
All lesions were small (mean size = 1.72 cm) and showed moderate hypointense signals on T1- and T2-weighted MRI sequences. They appeared isointense to slightly hyperintense on STIR images and slightly enhanced after gadolinium administration. To differentiate this entity from osteoblastic metastases, CT provides important additional information, as hematopoietic islands do not show sclerosis.
CONCLUSIONS
Hematopoietic islands within the axial skeleton can occur and mimic osteoblastic metastases. However, the combination of MRI and CT allows for making the correct diagnosis in most cases.
Topics: Aged; Bone Neoplasms; Bone and Bones; Female; Fluorodeoxyglucose F18; Gadolinium; Humans; Magnetic Resonance Imaging; Middle Aged; Positron Emission Tomography Computed Tomography; Retrospective Studies
PubMed: 35550061
DOI: 10.1186/s12891-022-05402-w -
Orthopaedic Surgery Jun 2021Measure and systematically evaluate the distribution of microhardness in the human skeleton.
OBJECTIVES
Measure and systematically evaluate the distribution of microhardness in the human skeleton.
METHODS
Three fresh corpses were obtained, aged 62 (male), 45 (female), and 58 years (male). Soft tissues were removed, and all axial and unilateral appendicular bones were freshly harvested. All three skeletons were examined by X-ray and computed tomography (CT) to exclude skeletal pathology. Only bones from donors with no known skeletal pathology were included in the study. Axial and unilateral appendicular skeleton bones from each of the three donors were obtained, except for ear ossicles, hyoid bone, tailbone, and 14 phalanges of the foot, for which samples were difficult to obtain. Precision bone specimens with a thickness of 3 mm, which were cut with a Buehler IsoMet 11-1280-250 low-speed diamond saw (Buehler, USA), were obtained from all important anatomic sites in a direction perpendicular to the mechanical axis of each bone. Micro-indentation (the Vickers hardness test) was performed on the surface of each specimen using a microhardness tester with a diamond indenter. Hardness value (HV) was computed for each indentation. Each bone specimen was divided into several regions of interest. Indentations were carefully made and computed. Then we analyzed the data to identify hardness distribution rules at different anatomic sites.
RESULTS
In total, 5360 indentations were made in 1072 regions of interest in each donor. Hardness of the axial and appendicular bones were all inhomogeneous depending on the anatomic sites, but the distribution of microhardness followed certain rules. The mean hardness value ranged from 24.46 HV (HV = hardness value, kgf/mm ) for the sacrum to 53.20 HV for the shaft of the tibia. The diaphysis was harder than the metaphysis, and the proximal and distal epiphysis had lower values (8.85%- 40.39%) than the diaphysis. Among the long bone diaphyses, the tibia cortical bone (51.20 HV) was the hardest, harder than the humerus (47.25 HV), the ulna (43.26 HV), the radius (42.54 HV), and the femur (47.53 HV). However, in some anatomic sites such as the lumbar vertebra (cortical bone 32.86 HV, cancellous bone 31.25 HV), the cortical shells were sometimes not harder than the internal cancellous bones. The lumbar vertebra (32.86 HV) was harder than the cervical vertebra (28.51 HV) and the thoracic vertebra (29.01 HV).
CONCLUSIONS
The distribution of microhardness in the human skeleton follows certain rules. These distribution rules could be used to predict the mechanical properties of bone and progress in this field could provide data for the basis of a new three-dimensional printing technique, which may lead to new perspectives for custom-made implants.
Topics: Biomechanical Phenomena; Bone and Bones; Cadaver; Female; Hardness; Humans; Male; Middle Aged
PubMed: 33973714
DOI: 10.1111/os.12841 -
The Canadian Veterinary Journal = La... Dec 2020
Topics: Animals; Atlanto-Axial Joint; Cervical Vertebrae
PubMed: 33299238
DOI: No ID Found -
European Journal of Radiology Sep 2022To describe the findings of focal high signal on T2 weighted (T2W) images of the bone marrow in the axial skeleton as assessed by whole-body MRI in healthy and...
OBJECTIVE
To describe the findings of focal high signal on T2 weighted (T2W) images of the bone marrow in the axial skeleton as assessed by whole-body MRI in healthy and asymptomatic children and adolescents.
MATERIAL AND METHODS
We assessed the bone marrow of the mandible, shoulder girdle, thorax, spine, and pelvis on water-only Dixon T2W sequences as part of a whole-body MRI protocol in 196 healthy and asymptomatic children aged 5-19 years. Intensity (0-2 scale) and extension (1-4 scale) of focal high signal areas in the bone marrow were scored and divided into minor or major findings, based on intensity and extension to identify the potentially conspicuous lesions in a clinical setting.
RESULTS
We registered 415 areas of increased signal in the axial skeleton whereof 75 (38.3%) were major findings. Fifty-eight (29.6%) individuals had at least one major finding, mainly located in the pelvis (54, 72%). We found no differences according to gender. The number of minor findings increased with age (p = 0.020), but there were no significant differences in the number of major findings. The most conspicuous findings were in the pelvis, spine and sternum.
CONCLUSION
Non-specific bone marrow T2W hyperintensities in the axial skeleton are frequently detected on whole-body MRI in healthy, asymptomatic children. Awareness of this is important as some findings may resemble clinically silent lesions in children with suspected multifocal skeletal disease.
Topics: Adolescent; Bone Marrow; Bone and Bones; Child; Humans; Magnetic Resonance Imaging; Thorax; Whole Body Imaging
PubMed: 35843014
DOI: 10.1016/j.ejrad.2022.110425 -
Differentiation; Research in Biological... 2022The cervical and anterior thoracic regions of mammals generally exhibit similar vertebral numbers and identities along the anterior-posterior axis. The position of the...
The cervical and anterior thoracic regions of mammals generally exhibit similar vertebral numbers and identities along the anterior-posterior axis. The position of the forelimbs along the axial skeleton is also generally conserved. In contrast, the number of lumbar and sacral vertebrae and pelvic position exhibit more variation, correlating with posture and locomotion. The molecular mechanisms that lead to these conserved and variable axial skeletal patterns between species are not fully understood. Here we use a human HOXB1-9 transgene to complement a HoxB1-9 deficiency in the mouse. In TgHOXB1-9 mice, human HOXB1, B2, B3, and B4 (HOXB1-4) genes were expressed in mouse embryos in patterns similar to mouse Hoxb1-4 genes. Human transgene expression rescued the cervical and anterior thoracic vertebral patterning defects of HoxB1-9 mice. In addition, the posterior shift in forelimb position of HoxB1-9 mice was rescued by the transgene. Interestingly, the position of the lumbar-sacral transition in both TgHOXB1-9; HoxB1-9 and TgHOXB1-9; HoxB1-9 mice was altered from six lumbar and four sacral vertebrae found in wild-type controls to five lumbar and five sacral vertebrae. The change in the position of the lumbar-sacral transition consequently altered the position of the pelvis. In contrast to the conserved expression of human HOXB1-4 genes in TgHOXB1-9 mouse embryos, the anterior border of human HOXB9 expression in the neural tube and paraxial mesoderm was shifted posteriorly by 2-3 somites compared to the anterior boundary of endogenous Hoxb9 expression. These findings suggest that conservation and variation in Hoxb/HOXB expression contributes to conserved and species-specific vertebral pattern and limb position.
Topics: Animals; Bone and Bones; Gene Expression Regulation, Developmental; Genes, Homeobox; Homeodomain Proteins; Humans; Mammals; Mice; Mice, Transgenic; Somites; Spine; Transcription Factors
PubMed: 36041259
DOI: 10.1016/j.diff.2022.07.002 -
Advances in Anatomy, Embryology, and... 2016Normal and abnormal vertebral development have been studied over the past 200 years at increasing levels of resolution as techniques for biological investigation have... (Review)
Review
Normal and abnormal vertebral development have been studied over the past 200 years at increasing levels of resolution as techniques for biological investigation have improved. Disordered development of the axial skeleton from the early embryonic period on leads to structurally malformed vertebrae and intervertebral discs and ribs causing the severe deformities of scoliosis, kyphosis, and kyphoscoliosis. Developmental malformation of the axial skeleton therefore has led to considerable biological and clinical interest. This work will detail our studies on the structural deformities of the vertebral column and adjacent ribs in the pudgy mouse [1] caused by mutations in the delta-like 3 (Dll3) gene of the Notch family [2]. While gene abnormalities in the pudgy mouse have been outlined, there has been no in-depth assessment of the histopathology of the pudgy vertebral and rib abnormalities that this study will provide. In addition, although congenital scoliosis has been recognized as a clinical problem since the mid-nineteenth century (1800s) [3] and accurately defined by radiography since the early twentieth century (1900s) [4-6], there have been few detailed histopathologic studies of human cases. We will also relate our histopathologic findings in the pudgy mouse to the histopathology of human vertebral and rib malformations in clinical cases of congenital scoliosis, one of which we defined in detail previously [7].
Topics: Abnormalities, Multiple; Animals; Biological Clocks; Cattle; Chick Embryo; Disease Models, Animal; Epigenesis, Genetic; Gene Expression Regulation, Developmental; Humans; Intervertebral Disc; Intracellular Signaling Peptides and Proteins; Klippel-Feil Syndrome; Membrane Proteins; Mice; Mice, Mutant Strains; Mutation; Notochord; Phenotype; Ribs; Scoliosis; Species Specificity; Spine
PubMed: 27655002
DOI: 10.1007/978-3-319-43151-2_1 -
Journal of Biomechanics May 2022Glenohumeral and scapulothoracic motion combine to generate humerothoracic motion, but their discrete contributions towards humerothoracic axial rotation have not been...
Glenohumeral and scapulothoracic motion combine to generate humerothoracic motion, but their discrete contributions towards humerothoracic axial rotation have not been investigated. Understanding their contributions to axial rotation is important to judge the effects of pathology, surgical intervention, and physiotherapy. Therefore, the purpose of this study was to investigate the kinematic coupling between glenohumeral and scapulothoracic motion and determine their relative contributions towards axial rotation. Twenty healthy subjects (10 M/10F, ages 22-66) were previously recorded using biplane fluoroscopy while performing arm elevation in the coronal, scapular, and sagittal planes, and external rotation in 0° and 90° of abduction. Glenohumeral and scapulothoracic contributions towards axial rotation were computed by integrating the projection of glenohumeral and scapulothoracic angular velocity onto the humeral longitudinal axis, and analyzed using one dimensional statistical parametric mapping and linear regression. During arm elevation, scapulothoracic motion supplied 13-20° (76-94%) of axial rotation, mainly via scapulothoracic upward rotation. The contribution of scapulothoracic motion towards axial rotation was strongly correlated with glenohumeral plane of elevation during arm elevation. During external rotation, scapulothoracic motion contributed 10° (8%) towards axial rotation in 0° of abduction and 15° (15%) in 90° of abduction. The contribution of scapulothoracic motion towards humerothoracic axial rotation could explain the simultaneous changes in glenohumeral plane of elevation and axial rotation associated with some pathologies and surgeries. Understanding how humerothoracic motion results from the functional coupling of scapulothoracic and glenohumeral motions may inform diagnostic and treatment strategies by targeting the source of movement impairments in clinical populations.
Topics: Adult; Aged; Biomechanical Phenomena; Humans; Humerus; Middle Aged; Range of Motion, Articular; Rotation; Scapula; Shoulder Joint; Young Adult
PubMed: 35367838
DOI: 10.1016/j.jbiomech.2022.111059 -
Anatomical Record (Hoboken, N.J. : 2007) Jul 2022Captive specimens in museum collections facilitate study of rare taxa, but the lifestyles, diets, and lifespans of captive animals differ from their wild counterparts....
Captive specimens in museum collections facilitate study of rare taxa, but the lifestyles, diets, and lifespans of captive animals differ from their wild counterparts. Trabecular bone architecture adapts to in vivo forces, and may reflect interspecific variation in ecology and behavior as well as intraspecific variation between captive and wild specimens. We compared trunk vertebrae bone microstructure in captive and wild xenarthran mammals to test the effects of ecology and captivity. We collected μCT scans of the last six presacral vertebrae in 13 fossorial, terrestrial, and suspensorial xenarthran species (body mass: 120 g to 35 kg). For each vertebra, we measured centrum length; bone volume fraction (BV.TV); trabecular number and mean thickness (Tb.Th); global compactness (GC); cross-sectional area; mean intercept length; star length distribution; and connectivity and connectivity density. Wild specimens have more robust trabeculae, but this varies with species, ecology, and pathology. Wild specimens of fossorial taxa (Dasypus) have more robust trabeculae than captives, but there is no clear difference in bone microstructure between wild and captive specimens of suspensorial taxa (Bradypus, Choloepus), suggesting that locomotor ecology influences the degree to which captivity affects bone microstructure. Captive Tamandua and Myrmecophaga have higher BV.TV, Tb.Th, and GC than their wild counterparts due to captivity-caused bone pathologies. Our results add to the understanding of variation in mammalian bone microstructure, suggest caution when including captive specimens in bone microstructure research, and indicate the need to better replicate the habitats, diets, and behavior of animals in captivity.
Topics: Animals; Bone Density; Bone and Bones; Mammals; Spine
PubMed: 34677912
DOI: 10.1002/ar.24817 -
Current Rheumatology Reports May 2020Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting mainly the peripheral skeleton in a symmetrical manner rather than the axial skeleton, but when it... (Review)
Review
PURPOSE OF REVIEW
Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting mainly the peripheral skeleton in a symmetrical manner rather than the axial skeleton, but when it occurs it can affect the cervical spine (CS). Although CS involvement is a frequent radiographic finding in RA, the clinical features are scarce, but potentially life-threatening with severe neurological deficits or even death due to brain stem compression. The commonest site of inflammation of the CS is the articulation between C and C vertebrae, the atlanto-axial region. The radiological finding observed in this region is the atlanto-axial subluxation (AAS). For the evaluation of CS in RA the classical diagnostic technique used mostly is conventional radiography (CR). Since CR does not provide good information regarding synovial inflammation, other imaging modalities are used such as magnetic resonance imaging and computed tomography. However, CR is the most valuable tool for screening CS in RA patients. Thus, we reviewed the literature until December 2019 for studies regarding CS radiological manifestations using CR in RA patients.
RECENT FINDINGS
We found that the frequency of radiological findings varies substantially, ranging between 0.7-95% in different studies. The commonest radiological feature was the AAS followed by subaxial subluxation. Because CS involvement can often be clinically asymptomatic, its assessment should not be forgotten by physicians and should be assessed using CR which is an easy to perform technique and gives important information as a screening tool.
Topics: Arthritis, Rheumatoid; Cervical Vertebrae; Humans; Magnetic Resonance Imaging; Radiography; Rheumatologists
PubMed: 32405896
DOI: 10.1007/s11926-020-00894-8