Bones

Osteoporosis.

Osteoporosis is a disease in which the bones become fragile and brittle. They fracture more easily than normal bone. Even a minor bump or fall can cause a serious fracture. Half of all women and one-third of men over 60 in Australia will have a fracture due to osteoporosis. 

Causes.

Osteoporosis is the most common type of bone disease.

Researchers estimate that about 1 out of 5 American women over the age of 50 have osteoporosis. About half of all women over the age of 50 will have a fracture of the hip, wrist, or vertebra (bones of the spine).

Osteoporosis occurs when the body fails to form enough new bone, when too much old bone is reabsorbed by the body, or both.

Calcium and phosphate are two minerals that are essential for normal bone formation. Throughout youth, your body uses these minerals to produce bones. If you do not get enough calcium, or if your body does not absorb enough calcium from the diet, bone production and bone tissues may suffer.

As you age, calcium and phosphate may be reabsorbed back into the body from the bones, which makes the bone tissue weaker. This can result in brittle, fragile bones that are more prone to fractures, even without injury.

Usually, the loss occurs gradually over years. Many times, a person will have a fracture before becoming aware that the disease is present. By the time a fracture occurs, the disease is in its advanced stages and damage is severe.

The leading causes of osteoporosis are a drop in estrogen in women at the time of menopause and a drop in testosterone in men. Women over age 50 and men over age 70 have a higher risk for osteoporosis.

Other causes include:

• Being confined to a bed
• Chronic rheumatoid arthritis, chronic kidney disease, eating disorders
• Taking corticosteroid medications (prednisone, methylprednisolone) every day for more than 3 months, or taking some antiseizure drugs
• Hyperparathyroidism
• Vitamin D deficiency

White women, especially those with a family history of osteoporosis, have a greater than average risk of developing osteoporosis. Other risk factors include:

• Absence of menstrual periods (amenorrhea) for long periods of time
• Drinking a large amount of alcohol
• Family history of osteoporosis
• History of hormone treatment for prostate cancer or breast cancer
• Low body weight
• Smoking
• Too little calcium in the diet.

Symptoms.

There are no symptoms in the early stages of the disease.

Symptoms occurring late in the disease include:

• Bone pain or tenderness
• Fractures with little or no trauma
• Loss of height (as much as 6 inches) over time
• Low back pain due to fractures of the spinal bones
• Neck pain due to fractures of the spinal bones
• Stooped posture or kyphosis, also called a "dowager's hump"

Exams and tests.

Bone mineral density testing (specifically a densitometry or DEXA scan) measures how much bone you have. Your health care provider uses this test to predict your risk for bone fractures in the future. For information about when testing should be done, see bone density test.

A special type of spine CT that can show loss of bone mineral density, quantitative computed tomography (QCT), may be used in rare cases.

In severe cases, a spine or hip x-ray may show fracture or collapse of the spinal bones. However, simple x-rays of bones are not very accurate in predicting whether someone is likely to have osteoporosis.

You may need other blood and urine tests if your osteoporosis is thought to be due to a medical condition, rather than simply the usual bone loss seen with older age.

Treatment.

The goals of osteoporosis treatment are to:

• Control pain from the disease
• Slow down or stop bone loss
• Prevent bone fractures with medicines that strengthen bone
• Minimize the risk of falls that might cause fractures

There are several different treatments for osteoporosis, including lifestyle changes and a variety of medications.

Medications are used to strengthen bones when:

• Osteoporosis has been diagnosed by a bone density study.
• Osteopenia (thin bones, but not osteoporosis) has been diagnosed by a bone density study, if a bone fracture has occurred.

BISPHOSPHONATES

Bisphosphonates are the primary drugs used to both prevent and treat osteoporosis in postmenopausal women.

• Bisphosphonates taken by mouth include alendronate (Fosamax), ibandronate (Boniva), and risedronate (Actonel). Most are taken by mouth, usually once a week or once a month.
• Bisphosphonates given through a vein (intravenously) are taken less often.

CALCITONIN

Calcitonin is a medicine that slows the rate of bone loss and relieves bone pain. It comes as a nasal spray or injection. The main side effects are nasal irritation from the spray form and nausea from the injectable form.

Calcitonin appears to be less effective than bisphosphonates.

HORMONE REPLACEMENT THERAPY

Estrogens or hormone replacement therapy (HRT) is rarely used anymore to prevent osteoporosis and are not approved to treat a woman who has already been diagnosed with the condition.

Sometimes, if estrogen has helped a woman, and she cannot take other options for preventing or treating osteoporosis, the doctor may recommend that she continue using hormone therapy. If you are considering taking hormone therapy to prevent osteoporosis, discuss the risks with your doctor.

PARATHYROID HORMONE

Teriparatide (Forteo) is approved for the treatment of postmenopausal women who have severe osteoporosis and are considered at high risk for fractures. The medicine is given through daily shots underneath the skin. You can give yourself the shots at home.

RALOXIFENE

Raloxifene (Evista) is used for the prevention and treatment of osteoporosis. Raloxifene is similar to the breast cancer drug tamoxifen. Raloxifene can reduce the risk of spinal fractures by almost 50%. However, it does not appear to prevent other fractures, including those in the hip. It may have protective effects against heart disease and breast cancer, though more studies are needed.

The most serious side effect of raloxifene is a very small risk of blood clots in the leg veins (deep venous thrombosis) or in the lungs (pulmonary embolus).

EXERCISE

Regular exercise can reduce the likelihood of bone fractures in people with osteoporosis. Some of the recommended exercises include:

• Weight-bearing exercises -- walking, jogging, playing tennis, dancing
• Resistance exercises -- free weights, weight machines, stretch bands
• Balance exercises -- tai chi, yoga
• Riding a stationary bicycle
• Using rowing machines

Avoid any exercise that presents a risk of falling, or high-impact exercises that may cause fractures.

DIET

Get at least 1,200 milligrams per day of calcium and 800 - 1,000 international units of vitamin D3. Vitamin D helps your body absorb calcium.Your doctor may recommend a supplement to give you the calcium and vitamin D you need.

Follow a diet that provides the proper amount of calcium, vitamin D, and protein. While this will not completely stop bone loss, it will guarantee that a supply of the materials the body uses to form and maintain bones is available.

High-calcium foods include:

• Cheese
• Ice cream
• Leafy green vegetables, such as spinach and collard greens
• Low-fat milk
• Salmon
• Sardines (with the bones)
• Tofu
• Yogurt

STOP UNHEALTHY HABITS

Quit smoking, if you smoke. Also limit alcohol intake. Too much alcohol can damage your bones, as well as put you at risk for falling and breaking a bone.

PREVENT FALLS

It is critical to prevent falls. Avoid sedating medications and remove household hazards to reduce the risk of fractures. Make sure your vision is good. Other ways to prevent falling include:

• Avoiding walking alone on icy days
• Using bars in the bathtub, when needed
• Wearing well-fitting shoes

MONITORING

Your response to treatment can be monitored with a series of bone mineral density measurements taken every 1 - 2 years.

Women taking estrogen should have routine mammograms, pelvic exams, and Pap smears.

Osteomyelitis

Osteomyelitis is an acute or chronic bone infection.

Causes.

Bone infection can be caused by bacteria (more common) or fungi (less common).

• Infection may spread to a bone from infected skin, muscles, or tendons next to the bone, as in osteomyelitis that occurs under a chronic skin ulcer (sore).
• The infection that causes osteomyelitis can also start in another part of the body and spread to the bone through the blood.
• A current or past injury may have made the affected bone more likely to develop the infection. A bone infection can also start after bone surgery, especially if the surgery is done after an injury or if metal rods or plates are placed in the bone.

In children, the long bones are usually affected. In adults, the feet, spine bones (vertebrae), and the hips (pelvis) are most commonly affected.

Risk factors are:

• Diabetes
• Hemodialysis
• Injected drug use
• Poor blood supply
• Recent trauma

People who have had their spleen removed are also at higher risk for osteomyelitis.

Symptoms

• Bone pain
• Fever
• General discomfort, uneasiness, or ill-feeling (malaise)
• Local swelling, redness, and warmth

Other symptoms that may occur with this disease:

• Chills
• Excessive sweating
• Low back pain
• Swelling of the ankles, feet, and legs

Exams and tests.

A physical examination shows bone tenderness and possibly swelling and redness.

Tests may include:

• Blood cultures
• Bone biopsy (which is then cultured)
• Bone scan
• Bone x-ray
• Complete blood count (CBC)
• C-reactive protein (CRP)
• Erythrocyte sedimentation rate (ESR)
• MRI of the bone
• Needle aspiration of the area around affected bones

Treatment.

The goal of treatment is to get rid of the infection and reduce damage to the bone and surrounding tissues.

Antibiotics are given to destroy the bacteria causing the infection. You may receive more than one antibiotic at a time. Often, the antibiotics are given through an IV (intravenously, meaning through a vein) rather than by mouth. Antibiotics are taken for at least 4 - 6 weeks, sometimes longer.

Surgery may be needed to remove dead bone tissue if you have an infection that does not go away. If there are metal plates near the infection, they may need to be removed. The open space left by the removed bone tissue may be filled with bone graft or packing material that promotes the growth of new bone tissue.

Infection of an orthopedic prosthesis, such as an artificial joint, may need surgery to remove the prosthesis and infected tissue around the area. A new prosthesis may be implanted in the same operation. More often, doctors wait to implant the prosthesis until the infection has gone away.

If you have diabetes, it will need to be well controlled. If there are problems with blood supply to the infected area, such as the foot, surgery to improve blood flow may be needed.

Osteochondrosis.

Osteochondrosis is a family of orthopedic diseases of the joint that occur in children and adolescents and in rapidly growing animals, particularly pigs, horses, and dogs. They are characterized by interruption of the blood supply of a bone, in particular to the epiphysis, followed by localized bony necrosis, and later, regrowth of the bone. This disorder is defined as a focal disturbance of endochondral ossification and is regarded as having a multifactorial etiology, so no one thing accounts for all aspects of this disease.

Cause.

The ultimate cause for these conditions is unknown, but the most commonly cited etiologic factors are rapid growth, heredity, trauma (or overuse), anatomic conformation, and dietary imbalances; however, only anatomic conformation and heredity are well supported by scientific literature. The way that the disease is initiated has been debated. Although failure of chondrocyte differentiation, formation of a fragile cartilage, failure of blood supply to the growth cartilage, and subchondral bone necrosis all have been proposed as the starting point in the pathogenesis, recent literature strongly supports failure of blood supply to growth cartilage as most likely. Osteochondrosis in pigs has been shown to be a condition responsive to supplementation with the essential trace element boron and may be a manifestation of boron deficiency.

Bone tumors.

A bone tumor is an abnormal growth of cells within a bone. A bone tumor may be cancerous (malignant) or noncancerous (benign).

Causes.

The cause of bone tumors is unknown. They often occur in areas of rapid bone growth. Possible causes include:

• Genetic defects passed down through families
• Radiation
• Injury

In most cases, no specific cause is found.

Osteochondromas are the most common noncancerous (benign) bone tumors, and occur most often in people between the ages of 10 and 20.

Cancers that start in the bones are referred to as primary bone tumors. Cancers that start in another part of the body (such as the breast, lungs, or colon) are called secondary or metastatic bone tumors. They behave very differently from primary bone tumors. Multiple myeloma often affects or involves the bone, but is not considered a primary bone tumor.

Cancerous (malignant) bone tumors include:

• Chondrosarcoma
• Ewing's sarcoma
• Fibrosarcoma
• Osteosarcomas

The cancers that most often spread to the bone are cancers of the:

• Breast
• Kidney
• Lung
• Prostate
• Thyroid

Symptoms.

• Bone fracture, especially fracture from slight injury (trauma)
• Bone pain, may be worse at night
• Occasionally a mass and swelling can be felt at the tumor site

Treatment.

Some benign bone tumors go away on their own and do not require treatment. Your doctor will closely monitor you and order periodic x-rays to see if the tumor shrinks or grows.

Surgery may be needed to remove the tumor in some cases.

Treatment for cancerous bone tumors that have spread from other parts of the body depends on where the cancer started. Radiation therapy may be given to prevent a fractures or to relieve pain.

Tumors that start in the bone are rare. They require treatment at centers with experience treating such cancer. After biopsy, a combination of chemotherapy and surgery is usually necessary. Radiation therapy may be needed before or after surgery.