0steoporosis This term literally means 'porous bones'.Compared with normal sturdy bones, the bones are sponge-like,insubstantial and brittle.This condition is usually diagnosed froa the X-ray appearance when the bones appear less substantial and, particularly,less dense than normal.As with a mumber of medical terms,the same word is used for a clinical state,a pathophysiological concept and a radiological appearance. The climical stare consists of features such as pain.deformities and fractures caused by relatively slicht force on a bome weakened by disease (pathological fractures).Norrally.a young person's ferur will only fracture when subjected to severe force as in a road traffic accident.However,the osteoporotic femur of an elderly person may fracture spontaneously because of the mormal stresses of weight bearing.The pathopoysfological comcept is of a boee that has gradually wasted,particularly through the loss of its collagen fibres,so that the calcium salts are not adequately reinforced.Theradfologfcal appearance is of bones that cast relatively thin pale shadows.How do we put these concepts together? A good place to start is with the dictionary definition of osteoporosis (Dorland's):'abeormal rarefaction of bone,seen most commonly in the elderly'.This draws attention to the effect of age.In fact,the bones of normal people grow and become denser and stronger during childhood and into early adulthood.Genetic. hornonal,nutritional and activity factors play a part in the ultinate strength in early adulthood,and thereafter bone strength gradually declines.Male bones in general are much stronger than female bones-so much so that one of the ways the sex of skeletal remains found by archeologists is determined is by the size and ruggedness of the long bones,with generally a clear gap between the male and fenale femur in terms of bulk.This is likely to be related to the increased strength of male muscles,because the pull of muscles and the stresses of gravity combine to develop strength in such bones.Having started smaller,femsle bones tend to decline in strength more rapidly than male bones,particularly after the memopause.Thus
Osteoporosis This term literally means 'porous bones'. Compared with normal sturdy bones, the bones are sponge-like, insubstantial and brittle. This condition is usually diagnosed from the X-ray appearance when the bones appear less substantial and, particularly, less dense than normal. As with a number of medical terms, the same word is used for a clinical state, a pathophysiological concept and a radiological appearance. The clinical state consists of features such as pain, deformities and fractures caused by relatively slight force on a bone weakened by disease (pathological fractures). Normally, a young person's femur will only fracture when subjected to severe force as in a road traffic accident. However, the osteoporotic femur of an elderly person may fracture spontaneously because of the normal stresses of weight bearing. The pathophysiological concept is of a bone that has gradually wasted, particularly through the loss of its collagen fibres, so that the calcium salts are not adequately reinforced. Theradiological appearance is of bones that cast relatively thin pale shadows. How do we put these concepts together? A good place to start is with the dictionary definition of osteoporosis (Dorland's): 'abnormal rarefaction of bone, seen most commonly in the elderly'. This draws attention to the effect of age. In fact, the bones of normal people grow and become denser and stronger during childhood and into early adulthood. Genetic, hormonal, nutritional and activity factors play a part in the ultimate strength in early adulthood, and thereafter bone strength gradually declines. Male bones in general are much stronger than female bones - so much so that one of the ways the sex of skeletal remains found by archeologists is determined is by the size and ruggedness of the long bones, with generally a clear gap between the male and female femur in terms of bulk. This is likely to be related to the increased strength of male muscles, because the pull of muscles and the stresses of gravity combine to develop strength in such bones. Having started smaller, female bones tend to decline in strength more rapidly than male bones, particularly after the menopause. Thus
in octagenarians and nonagenarians the problens of osteoporosis are largely.thouch not entirely,confined to females.Collapse of vertebrae with curvature of the spine (kyphosis)and loss of height are one manifestation.A more drastic effect is fracture of the ferur.referred to above.This nay lead to serious illness and death in some cases,but nodern techniques of repair with a netal plate or other prosthesis can often avoid this and lead to quite rapid recovery. The above description refers to the comon form of osteoporosis,related to age. The condition can also occur in younger people when the fibrous collagen natrix (which acts like the steel reinforcing in reinforced concrete)is attacked by certain hormonal disturbances.One of these is ercessive glucocort icoid activity,which can be due to adrenal tumours,but is more often due to therapeutic administration of the glucocorticoids (e.g prednisone)for conditions such as rheumatoid arthritis, asthm and polymyalgia,and to patients with organ transplants to prevent rejection. Excessive thyroid activity can also lead to a catabolic state in which the protein collagen fibres of bone are broken down. To prevent osteoporosis as far as possible,children,particularly females,are encouraged to ensure an adequate calciun intake mainly in the forn of nilk and to exercise adequately to build up strong bones.Adequate caleium and exereise should be continued throughout life -not to prevent loss of boee mass (which seens at present inevitable).but to minimize the rate of loss.Postmenopausal hormone replacement can help to reduce the rate of bone loss.and calciun supplements my help in situations where the condition is marked (assessed by bone scanming)or where glucocorticoid therapy increases the risk of osteoporosis. Finally.astecew/acfa cam be mentioned.It literally means softening of the bones and it can produce similar effects to osteoporosis.Strictly speaking it is a pathophysiological condition due to inadequate calciun salts in bone (corpare inadequate collagen in osteoporosis).This may be due to lack of calcium in the diet or to lack of activated vitanin D (dihydroxyeholecalciferol),which is needed for adequate absorption of calcium.In children,because the bones are indeed
in octagenarians and nonagenarians the problems of osteoporosis are largely, though not entirely, confined to females. Collapse of vertebrae with curvature of the spine (kyphosis) and loss of height are one manifestation. A more drastic effect is fracture of the femur, referred to above. This may lead to serious illness and death in some cases, but modern techniques of repair with a metal plate or other prosthesis can often avoid this and lead to quite rapid recovery. The above description refers to the common form of osteoporosis, related to age. The condition can also occur in younger people when the fibrous collagen matrix (which acts like the steel reinforcing in reinforced concrete) is attacked by certain hormonal disturbances. One of these is excessive glucocorticoid activity, which can be due to adrenal tumours, but is more often due to therapeutic administration of the glucocorticoids (e.g. prednisone) for conditions such as rheumatoid arthritis, asthma and polymyalgia, and to patients with organ transplants to prevent rejection. Excessive thyroid activity can also lead to a catabolic state in which the protein collagen fibres of bone are broken down. To prevent osteoporosis as far as possible, children, particularly females, are encouraged to ensure an adequate calcium intake mainly in the form of milk and to exercise adequately to build up strong bones. Adequate calcium and exercise should be continued throughout life - not to prevent loss of bone mass (which seems at present inevitable), but to minimize the rate of loss. Postmenopausal hormone replacement can help to reduce the rate of bone loss, and calcium supplements may help in situations where the condition is marked (assessed by bone scanning) or where glucocorticoid therapy increases the risk of osteoporosis. Finally, osteomalacia can be mentioned. It literally means softening of the bones and it can produce similar effects to osteoporosis. Strictly speaking it is a pathophysiological condition due to inadequate calcium salts in bone (compare inadequate collagen in osteoporosis). This may be due to lack of calcium in the diet or to lack of activated vitamin D (dihydroxycholecalciferol), which is needed for adequate absorption of calcium. In children, because the bones are indeed
particularly soft,deformities may be marked (rickets)with severe curvature of spine and leg bones.In adults,the effects are more like those of osteoporosis
particularly soft, deformities may be marked (rickets) with severe curvature of spine and leg bones. In adults, the effects are more like those of osteoporosis