Recurrent Low-Energy Fractures in Otherwise Healthy Children May Indicate Bone Fragility

OrthoMedia ◽  
2022 ◽  
2019 ◽  
Vol 105 (5) ◽  
pp. e2088-e2097 ◽  
Author(s):  
Leanne M Ward ◽  
David R Weber ◽  
Craig F Munns ◽  
Wolfgang Högler ◽  
Babette S Zemel

Abstract The last 2 decades have seen growing recognition of the need to appropriately identify and treat children with osteoporotic fractures. This focus stems from important advances in our understanding of the genetic basis of bone fragility, the natural history and predictors of fractures in chronic conditions, the use of bone-active medications in children, and the inclusion of bone health screening into clinical guidelines for high-risk populations. Given the historic focus on bone densitometry in this setting, the International Society for Clinical Densitometry published revised criteria in 2013 to define osteoporosis in the young, oriented towards prevention of overdiagnosis given the high frequency of extremity fractures during the growing years. This definition has been successful in avoiding an inappropriate diagnosis of osteoporosis in healthy children who sustain long bone fractures during play. However, its emphasis on the number of long bone fractures plus a concomitant bone mineral density (BMD) threshold ≤ −2.0, without consideration for long bone fracture characteristics (eg, skeletal site, radiographic features) or the clinical context (eg, known fracture risk in serious illnesses or physical-radiographic stigmata of osteoporosis), inappropriately misses clinically relevant bone fragility in some children. In this perspective, we propose a new approach to the definition and diagnosis of osteoporosis in children, one that balances the role of BMD in the pediatric fracture assessment with other important clinical features, including fracture characteristics, the clinical context and, where appropriate, the need to define the underlying genetic etiology as far as possible.


Author(s):  
Kulesa-Mrowiecka Małgorzata ◽  
Pihut Małgorzata ◽  
Słojewska Kinga ◽  
Sułko Jerzy

Osteogenesis imperfecta is a heterogeneous group of hereditary disorders of connective tissue diseases characterized by increased bone fragility, low growth, sometimes accompanied by abnormalities within the dentine, blue sclera, and partial or total hearing impairment. The changes may affect all joints, including the cervical spine and temporomandibular joints in the future, resulting in pain. The aim of the present study was to assess whether there is a relationship between the active range of motion of the cervical spine and the mobility of temporomandibular joints due to differential diagnosis in children with osteogenesis imperfecta, and to present a prevention algorithm for temporomandibular disorders. The study involved a group of 34 children with osteogenesis imperfecta, and the control group included 23 children (age 9.1 ± 3.8 years). Data were collected through an interview based on the author’s questionnaire, and the physical examination consisted in measuring the mobility of the cervical spine using an inclinometer (Cervical Range of Motion Instrument), the Helkimo scale, and linear measurements. In children with congenital bone fragility, there were acoustic symptoms from the temporomandibular joints more often than in healthy children. A correlation was found between the mobility of the cervical spine and temporomandibular joints in the study group. In the case of detecting irregularities in the temporomandibular joints, children were ordered to perform jaw-tongue coordination exercises.


Author(s):  
A. Garg ◽  
W.A.T. Clark ◽  
J.P. Hirth

In the last twenty years, a significant amount of work has been done in the theoretical understanding of grain boundaries. The various proposed grain boundary models suggest the existence of coincidence site lattice (CSL) boundaries at specific misorientations where a periodic structure representing a local minimum of energy exists between the two crystals. In general, the boundary energy depends not only upon the density of CSL sites but also upon the boundary plane, so that different facets of the same boundary have different energy. Here we describe TEM observations of the dissociation of a Σ=27 boundary in silicon in order to reduce its surface energy and attain a low energy configuration.The boundary was identified as near CSL Σ=27 {255} having a misorientation of (38.7±0.2)°/[011] by standard Kikuchi pattern, electron diffraction and trace analysis techniques. Although the boundary appeared planar, in the TEM it was found to be dissociated in some regions into a Σ=3 {111} and a Σ=9 {122} boundary, as shown in Fig. 1.


Author(s):  
G. G. Hembree ◽  
Luo Chuan Hong ◽  
P.A. Bennett ◽  
J.A. Venables

A new field emission scanning transmission electron microscope has been constructed for the NSF HREM facility at Arizona State University. The microscope is to be used for studies of surfaces, and incorporates several surface-related features, including provision for analysis of secondary and Auger electrons; these electrons are collected through the objective lens from either side of the sample, using the parallelizing action of the magnetic field. This collimates all the low energy electrons, which spiral in the high magnetic field. Given an initial field Bi∼1T, and a final (parallelizing) field Bf∼0.01T, all electrons emerge into a cone of semi-angle θf≤6°. The main practical problem in the way of using this well collimated beam of low energy (0-2keV) electrons is that it is travelling along the path of the (100keV) probing electron beam. To collect and analyze them, they must be deflected off the beam path with minimal effect on the probe position.


Author(s):  
Bertholdand Senftinger ◽  
Helmut Liebl

During the last few years the investigation of clean and adsorbate-covered solid surfaces as well as thin-film growth and molecular dynamics have given rise to a constant demand for high-resolution imaging microscopy with reflected and diffracted low energy electrons as well as photo-electrons. A recent successful implementation of a UHV low-energy electron microscope by Bauer and Telieps encouraged us to construct such a low energy electron microscope (LEEM) for high-resolution imaging incorporating several novel design features, which is described more detailed elsewhere.The constraint of high field strength at the surface required to keep the aberrations caused by the accelerating field small and high UV photon intensity to get an improved signal-to-noise ratio for photoemission led to the design of a tetrode emission lens system capable of also focusing the UV light at the surface through an integrated Schwarzschild-type objective. Fig. 1 shows an axial section of the emission lens in the LEEM with sample (28) and part of the sample holder (29). The integrated mirror objective (50a, 50b) is used for visual in situ microscopic observation of the sample as well as for UV illumination. The electron optical components and the sample with accelerating field followed by an einzel lens form a tetrode system. In order to keep the field strength high, the sample is separated from the first element of the einzel lens by only 1.6 mm. With a numerical aperture of 0.5 for the Schwarzschild objective the orifice in the first element of the einzel lens has to be about 3.0 mm in diameter. Considering the much smaller distance to the sample one can expect intense distortions of the accelerating field in front of the sample. Because the achievable lateral resolution depends mainly on the quality of the first imaging step, careful investigation of the aberrations caused by the emission lens system had to be done in order to avoid sacrificing high lateral resolution for larger numerical aperture.


2009 ◽  
Vol 18 (1) ◽  
pp. 19-24
Author(s):  
Maggie-Lee Huckabee

Abstract Research exists that evaluates the mechanics of swallowing respiratory coordination in healthy children and adults as well and individuals with swallowing impairment. The research program summarized in this article represents a systematic examination of swallowing respiratory coordination across the lifespan as a means of behaviorally investigating mechanisms of cortical modulation. Using time-locked recordings of submental surface electromyography, nasal airflow, and thyroid acoustics, three conditions of swallowing were evaluated in 20 adults in a single session and 10 infants in 10 sessions across the first year of life. The three swallowing conditions were selected to represent a continuum of volitional through nonvolitional swallowing control on the basis of a decreasing level of cortical activation. Our primary finding is that, across the lifespan, brainstem control strongly dictates the duration of swallowing apnea and is heavily involved in organizing the integration of swallowing and respiration, even in very early infancy. However, there is evidence that cortical modulation increases across the first 12 months of life to approximate more adult-like patterns of behavior. This modulation influences primarily conditions of volitional swallowing; sleep and naïve swallows appear to not be easily adapted by cortical regulation. Thus, it is attention, not arousal that engages cortical mechanisms.


Sign in / Sign up

Export Citation Format

Share Document