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Orthopedics - Diseases Of The Bone

implants replacement joint implant

Orthopedists are trained in treating several degenerative diseases such as arthritis, osteoporosis, carpal tunnel syndrome, and so on. The treatment options may vary from making diet changes, medications, steroid injections, and incorporating exercise in the daily routine to surgical procedures and hormone replacement therapy.

Arthritis is the condition where the surface of the joint (cartilage) is damaged or worn out causing a painful bone on bone condition. The most common causes are osteoarthritis and rheumatoid arthritis, but there are many less common conditions. The end result is the same in all of them: damage to the smooth surface of the joint producing rough surfaces that are painful when walked on or rubbed against each other. Joint replacement is probably the greatest advance in the treatment of arthritis in the past 20 years. In the right patient, joint replacement can give a new lease on life to people who would otherwise be crippled or confined to wheelchairs.

Total hip replacement is an operation where the surgeon removes the rough surfaces of bone at the joint and replaces them with new smooth surfaces of the implant used. The modern hip replacement implant is complex and made of several components that the surgeon carefully fits together during surgery. Some of the components are made of metal and others of a special hard medical plastic.

In modern hip replacement there are really two major choices. One choice is cementing the implant to the bone. Old studies have shown that cemented implants usually last on average 10-15 years before they loosen and become painful. Modern "third generation" improved cementing techniques may lengthen this period even more. Another choice is fixing the implant to the bone by making the bone grow into a specially prepared surface of the metal implant, so-called "bone-ingrowth" or "porous coated" implants. Bone ingrowth implants were developed because of the need to have implants last longer for young patients (40-50 years old) who had a long time to use the implants. Early studies were promising, but later studies have shown the newer third generation cementing techniques cause cemented implants to last longer than the bone-ingrowth implants. This is the case for the implants on the femur (thigh) side of the joint. Also, bone-ingrowth implants need time for the bone to grow into the implant and therefore can be somewhat painful for a year or more until that occurs. The cemented implants however, are solid as soon as the operation is completed, and therefore are less painful in the early stages. On the socket side of the hip joint, there does not seem to be an appreciable difference between the two. Most members of the American Academy of Orthopedic Surgeons feel that a "hybrid" hip replacement (cemented femur, bone-ingrowth socket) presents the best option today.

Osteoporosis occurs when bone mass is less than one would expect for the average person of a specific age. Osteoporosis can have many causes. The reduction of the female hormone estrogen after menopause is the most common. Persons who have increased thyroid hormone (hyperthyroid) can become osteoporotic. Patients receiving steroids for long periods of time, either as medication or because of adrenal disease (Cushing's disease) are also at risk.

Since calcium is an essential ingredient of bone, it is necessary to have adequate calcium intake either in the diet or in supplements. Without vitamin D, calcium cannot be taken up into the bone and therefore adequate vitamin D intake is also required.

There are several preventative measures that can be followed to help avoid osteoperosis. One of the simplest recommendations is exercise. Exercise is an important factor in maintaining bone mass, especially after menopause (in women). Ensuring sufficient vitamin D intake with 1,000-1,500 mg of calcium supplements per day is suggested for women five years after menopause. Estrogen-Progestin replacement therapy five years after menopause can reduce the chance of osteoperosis, unless the potential for breast cancer is high. In cases where women cannot take estrogens and have evidence of osteoporosis Fosomax is available. Estrogen replacement (combined with progestin) is FDA approved for and has become the defacto standard of care for both the treatment and prevention of osteoporosis in the post-menopausal woman who does not have a history or risk factors for breast cancer, even though its cardiovascular benefits are the more pressing reason for their use.

See also Skeletal system.

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