Osteoporosis

Osteoporosis is rebuilding bone structure, accompanied by reduction of bone beams in a unit volume of the bone. On radiographs osteoporosis is manifested by increased transparency bone figure, the sparsity of the bone structure and the thinning of the cortical layer under normal shape and size of the bones. Osteoporosis may be limited to an area of bone (local), to capture some bones (regional), all the bones of the limbs (common) or full skeletal system). Osteoporosis develops in old age, and also as a consequence of fractures and inflammation of bone tissue, with osteodistrofia (see) and other diseases.

Osteoporosis (from the Greek. osteon - bone and poros - time) - rarefaction of bone tissue structure.
X-ray examination is the only objective means living determination of osteoporosis. On the basis of the x-ray pictures can solve the question of the presence or absence of osteoporosis, install it, localization and degree of distribution, to study its nature, form and phase. Osteoporosis begins simultaneously with the calling his main illness, but radiographically he detected only after a certain period. In clinical conditions it is about the second week after the onset of acute inflammatory process or after trauma. Defined radiographically Acting is already significantly pronounced pathological shift in the structure of the bone. Discovery's Acting is possible only after a significant loss of bone substance (about 20%), and during follow-up required the loss or profit of bone in the range of 10%to a series of sophisticated x-ray revealed a distinct gradation shadow x-ray pictures. From the true bone atrophy, osteoporosis is different in that the affected O. bones maintain normal shape and size, and the Acting is first of all a deep neurotrophic quality pathological process in the bone tissue.
Osteoporosis can be expressed in two forms: spotted or speckled, and uniform. General x-ray symptom for both types of O. is increased transparency bone pattern. If spotted osteoporosis is characterized by multiple, more or less densely located in small foci of enlightenment against the background of all bone structural drawing (Fig. 1), Acting under uniform picture enlightenment figure has diffuse uniform character. Dramatically expressed O. bone can become so permeable to x-rays and original vitreous that its shadow intensity does not differ from the shade of the surrounding soft tissues and bone is allocated only through the lining the fine lines of the cortical layer. The fundamental differences between spotted and even osteoporosis does not exist, spotted often Acting is the expression of early pathological process in the future usually goes in uniform. In other words, spotted O.
often a phase Acting, not a special form.

Fig. 1. Spotted (or peg) osteoporosis head of the humerus during arthritis.
Fig. 2. Osteoporosis in tuberculous arthritis left arm-carpal joint (J); 2 - normal bone structure.

Osteoporosis is local, regional, widespread and systematic. Local O. limited to the area where is located the main pathological process. Regional O. takes a whole anatomic area, such as specific joint in tuberculous his defeat (Fig. 2). Common O. captures the skeleton of a limb, for example, when firearms nerve damage or extensive burns. A special case is the system O. affecting all the bones of the skeleton. Like any system lesions, generalized systemic osteoporosis is always called common cause, outside of the bone system. Its physiological prototype is senile Acting System Acting can be nutritional, toxic, elimination, endocrine and hormonal, neurotrophic origin.
Pathological anatomy. For osteoporosis resorption processes prevail over osteogenesis O. characterized by the expansion gaverova channels, thinning compact discs (Fig. 3)owing to what they structure resemble spongy substance (sparizione compact discs). In the cancellous bone beams thinned, their number is reduced (Fig. 4).

Fig. 3. Sparizione cortical layer.
Fig. 4. Osteoporosis of the spine.

The acting is due to the decrease in bone mass, which may be associated with increased its resorption at normal rates of oppozicii bones. It is also possible development Acting as the result of reducing the rate of oppozicii when normally proceeding resorption.
With the rapid development of osteoporosis (such as acute atrophy of sodeca) bone resorption proceeds by type auxiliary, at a slow pace - the type of smooth or lacunar. Disappear simultaneously and mineral and organic part of the bone substance. The presence, in some cases, O. (rickets, osteomalacia) on the surface of bone structures osteodes tissue is not decalcomania bones in the process of resorption, and with violation of the formation of bone substance under these pathological processes.
The strength of bones in osteoporosis falls, resulting easily happen fractures, deformations of bones, especially of the vertebral bodies. In the latter as a result of cartilage and bone fracture reflex records may be offset part of the nucleus pulposus in a sponge-like material with formation schmorl's nodule. Especially frequent femoral neck fractures, compression fractures of the vertebral bodies. It is also characteristic appearance in the cancellous bone of microfractures followed by the formation of micromodules.
The acting is local and General. Local O. occurs in chronic osteomyelitis, bone tumors, after x-ray irradiation with therapeutic purposes (for example, in the bones of the pelvis after radiotherapy cancer of the uterus), etc., Occurrence of O. associated with disorders of blood circulation and trophic disorders bone accompanying the underlying disease. General Acting develops when the General disorder of metabolism - osteodistrofia, starvation, beriberi (a, C), some endocrine diseases, prolonged bed rest, especially in old age, etc.,
It should be emphasized that in osteoporosis occurs not only bone atrophy, but significant restructuring respectively changing functional-morphological conditions. This explains, for example, thickening of some systems of beams of the spongy substance of the vertebral bodies, the neck of the femur, bearing Max. mechanical load in conditions of the Acting Cm. the Bone.