Metabolic Bone Disease Osteoporosis example essay topic

Bone diseases most directly influence the ability to walk or to move any part of the body -- hands, limbs, neck, and spine. They are related to joint disorders -- ARTHRITIS, COLLAGEN DISEASE, DISLOCATION of joints, and RHEUMATISM. The medical specialty pertaining to bone disorders is ORTHOPEDICS. Fractures are the most common bone disorders. They can occur as the result of an accident or be secondary to metabolic diseases. Fractures are life-threatening to aged people having the metabolic bone disease OSTEOPOROSIS, in which bones become porous and brittle.

A person, mostly women, having osteoporosis may break a hip during a fall and possibly die from complications. Birth Defects Congenital bone diseases constitute a wide spectrum, ranging from the unimportant -- for instance, mild bow legs -- to severe lesions, such as spina bifida, in which the lower end of the spine fails to develop properly and the baby is born with paralysis and misshapen vertebrae. Congenital diseases may have hormonal bases: for example, fibrous DYSPLASIA, in which fibrous tissue replaces that of some bones, often results in bone deformity; in addition, some girls with this disease physically mature so early that they are capable of pregnancy and childbirth at the age of seven. Congenital defects also may have genetic bases, as in families who have extra fingers or toes or in the disease osteogenesis imperfecta, in which children have such brittle bones that many are fractured. Disorders of growth and development include several kinds of dwarfism and gigantism. Bones or limbs may develop deformity as the result of known causes, such as the infection poliomyelitis, or unknown or variable causes, such as curvature of the spine (SCOLIOSIS) or CLUBFOOT.

Infections Infections of bone, called osteomyelitis, are usually caused by pus-producing bacteria, especially Staphylococcus and Streptococcus. Before the development of antibiotics, children frequently contracted this disease. Today bone infections are introduced primarily through fractures and during surgical operations. People infected with syphilis, tuberculosis, leprosy, or yaws are susceptible to bone damage. Metabolic Disorders Metabolic abnormalities often involve defects in the storage of minerals, particularly calcium and phosphate ions, in the skeleton. Diseases of the kidney can cause a metabolic imbalance of phosphate and calcium so that weakening of the bone occurs.

Other metabolic bone diseases are osteoporosis, gout, OSTEOARTHRITIS, and PAGET " DISEASE. Nutritional Disorders Nutritional deficiencies that result in bone damage include RICKETS in children and osteomalacia in adults, caused by a lack of vitamin D. In children, calcium and phosphate are poorly distributed on bones during development, resulting especially in deformity of the legs and arms. In adults, bones of the spine, pelvis, and legs become the bones weaken. SCURVY -- caused by alack of vitamin C -- also affects bone tissues. A study in the late 1980's indicated that the mineral boron is nutritionally important, as well. Apparently, it reduces loss of the bone minerals calcium, phosphate, and magnesium and helps to maintain adequate blood levels of estrogen and testosterone, which play a role in bone health.

Toxic Diseases The importance of toxic conditions of bones to public health became evident because of such tragedies as thalidomide-induced birth defects and radium poisoning. The drug THALIDOMIDE was given to pregnant women in England and Germany for use as a sleeping pill and to treat nausea. It caused an epidemic in which thousands of babies were born with deformed or missing limbs. Women employed during the 1920's as painters of luminescent clock dials were unwittingly exposed to radium from the paint as they licked their brushes. Many died, either from anemia or from bone cancer, alerting doctors to the dangers of radioactivity and subsequent radiation injury.

Other types of toxic bone disease include fluoride and lead poisoning and overexposure to X rays. Tumors Bone tumors, although not common, are not rare; benign tumors are more common than malignant ones (sarcomas). Metastatic tumors -- those which arise primarily in another tissue and spread by the blood to the skeleton, where they usually grow in many places at once -- are very common in bones, although tumors originating in bones are not. The skeleton is second only to the lung as a site for metastases of CANCER. More fatalities and greater pain are associated with metastases of bone than with any other type of cancer.

Treatments Treatments for bone diseases vary as widely as the causes. Physical disorders often require mechanical therapy -- for instance, plaster casts for fractures and braces and splints for support. Drugs are used for metabolic problems, and antibiotics for infections. Corrective surgery benefits many people having such diseases as scoliosis. Therapy can involve REHABILITATION MEDICINE, by which victims of injury, deformity, and amputation can learn how to function as normally as possible.

Jonathan Cohen, M.D.

Bibliography

A voli, L.V., and K rane, S.M., eds., Metabolic Bone Disease, 2d ed. (1987);
Berry, C.L., ed., Bone and Joint Disease (1982);
Greenfield, G.B., Radiology of Bone Diseases, 4th ed. (1986);
Marot eaux, Pierre, Bone Diseases of Children, trans. by H. Kaufmann (1979);
Uhthoff, H.K., ed., Current Concepts of Bone Fragility (1986).