Skeletal fragility

Turner CH (2002) Biomechanics of bone Determinants of skeletal fragility and bone quality. Osteoporos Int 13 97-104... 

Osteoporosis is a condition of skeletal fragility due to progressive loss of bone mass. It occurs in the elderly of both sexes, but is most pronounced in postmenopausal women. Osteoporosis is characterized by frequent bone fractures, which are a major cause of disability among the elderly. Figure 43.1 showns changes in bone morphology seen in osteoporosis. 

Osteoporosis is a condition of low bone mass and microarchitectural disruption that results in fractures with minimal trauma. Characteristic sites of fracture include vertebral bodies, the distal radius, and the proximal femur, but osteoporotic individuals have generalized skeletal fragility, and fractures at sites such as ribs and long bones also occur. Fracture risk increases exponentially with age, related both to decreased bone density and to factors such as decreased muscle strength and increased risk of falls. 

Visekruna M, Wilson D, McKiernan FE. Severely suppressed bone turnover atypical skeletal fragility. J Clin Endocrinol Metab 2008 93(8) 2948-52. 

The definition of osteoporosis is (NIH 2000) A systemic skeletal disease characterized by low bone mass and micro architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture . 

A variety of diseases can affect bone and its structure. Paget s disease, for example, is a disorder arising from abnormal osteoclasts, characterized by exeessive bone resorption followed by replacement of the normal mineralized bone with structurally weak, poorly mineralized tissue. However, the most important bone disease is osteoporosis. This is a skeletal bone disease characterized hy microarchitectural deterioration of bony tissue and loss of bone mass, yielding increased susceptibility to bone fracture and bone fragility. In the United States, osteoporosis results in 1.5 million hone fractures annually, with 250,000 of these being hip fractures that sometimes ultimately culminate in patient death. There is a variety of therapies for the prevention and treatment of osteoporosis. 

Copper is an essential component of numerous key metalloenzymes which are critical in melanin formation, myelin formation and crosslinking of collagen and elastin. Copper plays a vital role in hemopoiesis, maintenance of vascular and skeletal integrity, and structure and function of the nervous system. Thus a deficiency of copper can lead to a variety of adverse effects such as increased fragility in bones, aneurysm formation in arteries and a loss of lysyl oxidase activity in cartilage.54 57 Articles on copper also appear in Siget1, volumes 3 and 5, all of volumes 12 and 13, and volume 14,... 

An estimated 75 million people are affected by osteoporosis to some degree in the United States, Europe, and Japan. Osteoporosis is a systematic skeletal disease characterized by bone mass and microarchitectural deterioration with a consequent increase in bone fragility and susceptibility to fracture. Operationally, osteoporosis can be defined as a certain level of bone mineral density. The definition of osteoporosis is somewhat arbitrary and is based on epidemiological data relating fracture incidence to bone mass. Uncertainty also is introduced due to variability in bone densitometry measurements. Other clinical measures to assess the skeleton include collagen cross-links (measure of bone resorption) and levels of bone-specific alkaline phosphatase and osteocalcin (bone formation). A list of biochemical markers of bone remodeling is provided in Table 37-3. Measurement of total serum alkaline phosphatase level and urinary hydroxyproline or calcium levels is of limited value. 

Low-level environmental exposure to Cd may thus promote skeletal demineralization, which may lead to increased bone fragility and raised risk of fractures. Therefore it has been proposed that a CdU value of 2 pg Cd/g creatinine should be regarded as the maximum tolerable internal Cd dose for individuals from the general population. Hence, one may assume that in the early 1990 s about 10% of the general population in Belgium exceeded this threshold value and that it amoimted to 20% in the rural area with historical pollution by Cd from non-ferrous smelters. In this area, a clear-cut impact of a preventive action to decrease the Cd transfer from the environment to the inhabitants was observed, because the Cd concentration... 

CHRONIC HEALTH RISKS emphysema risk of lung cancer increased frequency of kidney stone formation impaired neurological development skeletal malformations fragile bones high blood pressure decreased birth weights.. 

Osteoporosis is a skeletal disease that is characterized by loss of bone mass as well as microarchitectural deterioration of the bone tissue. This disease is associated with increased bone fragility and susceptibility to fracture. It is a condition that is characterized not by inadequate bone formation but, rather, by a deficiency in the production of well-mineralized bone mass. Whereas no medical cause typically is evident in primary osteoporosis (3), secondary osteoporosis classically stems from medical illness or medication use. There are two types of primary adult osteoporosis, type I, or postmenopausal, and type II, or senile (Table 35.1). In type I osteoporosis, there is an accelerated rate of bone loss via enhanced resorption at the onset of menopause. In this form of the disease, the loss of trabecular bone is threefold greater than the loss of cortical bone. This disproportionate loss of bone mass is the primary cause of the vertebral crush fractures and the wrist and ankle fractures experienced by postmenopausal women. In type II osteoporosis, which is associated with aging, the degree of bone loss is similar in both trabecular and cortical bone (5) and is caused by decreased bone formation by the osteoblasts. 

Saville, P.D. Water fluoridation effect on bone fragility and skeletal calcium content in the rat. J. Nutr. 91, 353-357 (1967)... 

Excessive intake of fluoride leads to brown discoloration of the teeth (dental fluorosis). A concentration above about 12 ppm in drinking water, as occurs naturally in some parts of the world, is associated with excessive deposition of fluoride in the bones, leading to increased fragility (skeletal fluorosis). 

Osteoporosis is a major public problem, it is a skeletal disease characterized by low bone mass and microarchitec-tural deterioration. Osteoporotic patient occur fragility fracture frequently, and the common positions were vertebral, hip, wrist. There was 1.66million hip fracture in worldwide [1], 1,197,000 in women and 463,000 in men. Dynamic hip screw was the standard treatment in stable femoral proximal fracture. But in unstable fracture, it has high failure rate. Unstable fracture has the weak structure, it cause that the force loads on femoral head. Then the cut-out complication will happen, especially on osteoporotic patient. The hip biomechanics can help us to design new device and develop new technique to solve the clinical problem. From the diagram of the lines of stress in the upper femur, the lesser trochanter supply the compression... 

Another example of a genetic mutation in a lysosomal cathepsin that causes a specific human disorder has recently come to light [43]. The disease is pycnodysos-tosis which is an autosomal recessive skeletal dysplasia. Clinical features of pycno-dysostosis were first described in 1962 by Maroteaux and Lamy [60] to include bone fragility, dental abnormalities, reduced stature and skull deformities with a delay in closure of the cranial sutures. The disease experienced considerable acclaim due to the initial prediction by Maroteaux and Lamy, recently refuted [61], that this was the genetic disorder suffered by the famous French impressionist artist Toulouse-... 

ISC (I/O-11.3) searches employed restricted MAXSTEP parameters (and increased MAXCYCLE parameters) to preserve fragile CAS convergence from step to step of geometry optimization.] As seen in EO-11.3, the twisted ISC(So/Ti) geometry resembles that of the CI(So/Si) species (FO-11.2) with altered skeletal bond lengths and slightly inverted pyramidahzation at C(2). 

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