Tag Archives: Paget’s disease of bone

Paget’s Disease of Bone

Definition:
Paget’s disease of bone causes affected bones to become enlarged and misshapen. Our bones are living tissue, and our bodies are constantly breaking down old bone and replacing it with new bone. In Paget’s disease, however, old bone is broken down and replaced at a faster rate than normal. The new bone is larger and weaker than normal bone.

Click to see the picture


Click to see the picture

Paget’s disease can occur in any bone in the body, but it is most common in the pelvis, spine, skull, and leg bones. It may occur in just one bone or in several bones, but it does not affect the entire skeleton or spread from affected bones to normal bones. Common symptoms include pain, misshapen bones, and a greater chance of broken bones.

Decisions about treating Paget’s disease can be complicated because: 1) no two people are affected in exactly the same way by the disease, and 2) it is sometimes difficult to predict whether a person with Paget’s disease who shows no signs of the disorder will develop symptoms or complications, such as a bone fracture, at a later date. Although there is no cure for Paget’s disease, medications (bisphosphonates and calcitonin) can help control the disorder and lessen pain and other symptoms. Paget’s disease experts recommend that these medications be taken by people with Paget’s disease who: have bone pain, headache, back pain, or a nerve-related symptom (such as “shooting” pains in the leg) that is directly associated with the disease; have elevated levels of serum alkaline phosphatase (SAP) in their blood; display evidence that a bone fracture will occur; require pretreatment therapy for affected bones that require surgery; have active symptoms in the skull, long bones, or vertebrae (spine); have the disease in bones located next to major joints, placing them at risk of developing osteoarthritis; develop a rare condition called hypercalcemia that occurs when a person with several bones affected by Paget’s disease and a high SAP level is immobilized.

Today’s medications, especially when started before complications begin, are often successful in controlling the disorder. Paget’s disease is rarely diagnosed in people less than 40 years of age. Women are more commonly affected than men. Prevalence of Paget’s disease ranges from 1.5 to 8.0 percent, depending on age and country of residence. Prevalence of familial Paget’s disease (where more than one family member has the disease) ranges from 10 to 40 percent in different parts of the world.[citation needed] Because early diagnosis and treatment is important, after age 40, siblings and children of someone with Paget’s disease may wish to have an alkaline phosphatase blood test every two or three years. If the alkaline phosphatase level is above normal, other tests such as a bone-specific alkaline phosphatase test, bone scan, or X-ray can be performed.

Named for Sir James Paget (1814–1899)

Symptoms:
Most people who have Paget’s disease of bone experience no symptoms. When symptoms do occur, the most common complaint is bone pain. The disease may affect only one or two areas of your body, or may be widespread. Your signs and symptoms, if any, will depend on the part of your body that’s affected, including:

*Pelvis. Paget’s disease of bone in the pelvis can cause hip pain.

CLICK & SEE

*Skull. An overgrowth of bone in the skull can cause hearing loss or headaches.

CLICK & SEE

*Spine. If your spine is affected, nerve roots can become compressed. This can cause pain, tingling and numbness in an arm or leg.

CLICK & SEE

*Leg. As the bones weaken, they may bend — causing you to become bow-legged. Enlarged and misshapen bones in your legs can put extra stress on nearby joints, which may cause wear-and-tear arthritis in your knee or hip.

 CLICK & SEE

 Click to see the pictures

Other common  Symptoms are:

•Bone and joint pain.
•Deformity of a bone such as bowing of the leg, skull enlargement or curvature of the spine.
•Muscle weakness due to bones pressing on nerves.
•Bone fractures resulting from minor injury (bone affected by Paget’s disease has a disorganised structure and is mechanically weak).
•Arthritis (when Paget’s affects bone around a joint).
•Deafness, vision disturbance, dizziness and tinnitus when enlargement of skull bones puts pressure on vital nerves.
•A “hot spot” over an area of affected bone due to high blood supply.
Causes:
Even after you’ve reached your full height, your bones don’t stop growing. Bone is living tissue engaged in a continual process of renewal. During this constant process called remodeling, old bone is removed and replaced by new bone. Paget’s disease of bone disrupts this process.

Early in the course of the disease, old bone starts breaking down faster than new bone can be built. Over time, your body responds by generating new bone at a faster than normal rate. This rapid remodeling produces bone that’s softer and weaker than normal bone, which can lead to bone pain, deformities and fractures.

Scientists haven’t identified a cause of Paget’s disease of bone, though they have discovered several genes that appear to be linked to the disorder.

Some scientists believe Paget’s is related to a viral infection in your bone cells that may be present for many years before problems appear. Hereditary factors seem to influence whether you’re susceptible to the disease.
Risk Factors:
*Age. People older than 40 are the most likely to develop Paget’s disease of bone.

*Sex. Men are more commonly affected than are women.

*National origin. Paget’s disease of bone is more common in people of Anglo-Saxon descent.

*Family history. If you have a close relative who has Paget’s disease of bone, you are much more likely to develop the condition yourself.

Complications:
In most cases, Paget’s disease of bone progresses slowly. The disease can be managed effectively in nearly all people. Possible complications include:

*Fractures. Bones affected by Paget’s disease are large and dense, but also weak and brittle. This makes them more prone to fractures. More blood vessels are created in these deformed bones, so they bleed more during repair surgeries.

*Osteoarthritis. Misshapen bones can increase the amount of stress on nearby joints, which can cause osteoarthritis.

*Heart failure. Unusually extensive Paget’s disease may force your heart to work harder to pump blood to the affected areas of your body. In people with pre-existing heart disease, this increased workload can lead to heart failure.Bone cancer. Bone cancer occurs in less than 1 percent of people with Paget’s disease.
Diagnosis:
DiagnosisPaget’s disease may be diagnosed using one or more of the following tests:

*Pagetic bone has a characteristic appearance on X-rays. A skeletal survey is therefore indicated.

*An elevated level of alkaline phosphatase in the blood in combination with normal calcium, phosphate, and aminotransferase levels in an elderly patient are suggestive of Paget’s disease.

*Bone scans are useful in determining the extent and activity of the condition. If a bone scan suggests Paget’s disease, the affected bone(s) should be X-rayed to confirm the diagnosis.
Associated medical conditions:
Paget’s disease may lead to other medical conditions, including:

*Arthritis may be caused by bowing of long bones in the leg, distorting alignment and increasing pressure on nearby joints. In addition, pagetic bone may enlarge, causing joint surfaces to undergo excessive wear. In these cases, pain may be due to a combination of Paget’s disease and osteoarthritis.

*Loss of hearing in one or both ears may occur when Paget’s disease affects the skull and the bone that surrounds the inner ear. Treating the Paget’s disease may slow or stop hearing loss. Hearing aids may also help.

*Cardiovascular disease can result from severe Paget’s disease (i.e. with more than 15% skeletal involvement). Arteriovenous connections can often form in the bone, and so the heart has to work harder (pump more blood) to ensure adequate oxygen supply to the tissues. This increase in cardiac output can lead to calcification of the aortic valve, and the resulting aortic stenosis causes left ventricular hypertrophy and eventually high-output congestive failure.

*Kidney stones are somewhat more common in patients with Paget’s disease.

*Pagetic bone can cause nervous system problems, such as pressure on the brain, spinal cord, or nerves, and reduced blood flow to the brain and spinal cord.

*Rarely, Paget’s disease is associated with the development of osteosarcoma (malignant tumor of bone).
*When there is a sudden onset or worsening of pain, sarcoma should be considered.

*When Paget’s disease affects the facial bones, the teeth may become loose. Disturbance in chewing may occur.

*Rarely, when the skull is involved, the nerves to the eye may be affected, causing some loss of vision.

*Angioid streaks may develop, possibly as a result of calcification of collagen or other pathological deposition.

Paget’s disease is not associated with osteoporosis. Although Paget’s disease and osteoporosis can occur in the same patient, they are different disorders. Despite their marked differences, several treatments for Paget’s disease are also used to treat osteoporosis.

Treatment:
Endocrinologists (internists who specialize in hormonal and metabolic disorders), rheumatologists (internists who specialize in joint and muscle disorders), orthopedic surgeons, neurologists, and otolaryngologists are generally knowledgeable about treating Paget’s disease, and may be called upon to evaluate specialized symptoms.

Drug therapy
The goal of treatment is to relieve bone pain and prevent the progression of the disease. The U.S. Food and Drug Administration has approved the following treatments for Paget’s disease:

Bisphosphonates
Five bisphosphonates are currently available. In general, the most commonly prescribed are: risedronic acid (Actonel), alendronic acid (Fosamax) and pamidronic acid (Aredia). Etidronic acid (Didronel) and other bisphosphonates may be appropriate therapies for selected patients, but are less commonly used. As a rule, bisphosphonate tablets should be taken with 200-250 mL (6–8 oz) of tap water (not from a source with high mineral content) on an empty stomach. None of these drugs should be used by people with severe kidney disease.

*Etidronate disodium (Didronel) in tablet form is available in 200–400 mg doses. The approved regimen is once daily for six months; the higher dose (400 mg) is more commonly used. No food, beverage, or medications should be consumed for two hours before and after taking. The course should not exceed six months, but repeat courses can be given after rest periods, preferably of three to six months duration.

*Pamidronate disodium (Aredia) in intravenous form: the approved regimen uses a 30 mg infusion over four hours on each of three consecutive days, but a more commonly used regimen is 60 mg over two to four hours for two or more consecutive or nonconsecutive days.

*Alendronate sodium (Fosamax) is given as tablets of 40 mg once daily for six months; patients should wait at least 30 minutes after taking before eating any food, drinking anything other than tap water, taking any medication, or lying down (patient may sit).

*Tiludronate disodium (Skelid) in two tablets of 200 mg are taken once daily for three months; they may be taken any time of day, as long as there is a period of two hours before and after resuming food, beverages, and medications.

*Risedronate sodium (Actonel) as a 30 mg tablet taken once daily for 2 months is the prescribed regimen; patients should wait at least 30 minutes after taking before eating any food, drinking anything other than tap water, taking any medication, or lying down (patient may sit).

*Zoledronic acid (Reclast, Aclasta) is given as an intravenous infusion; a single dose (5 mg over 15 minutes) is effective for two years.

Calcitonin
*Miacalcin is administered by injection; 50 to 100 units daily or three times per week for 6–18 months. Repeat courses can be given after brief rest periods. Miacalcin may be appropriate for certain patients, but is seldom used. The nasal spray form of this drug is not approved for the treatment of Paget’s disease.

Diet and regular exercise:
In general, patients with Paget’s disease should receive 1000–1500 mg of calcium, adequate sunshine, and at least 400 units of vitamin D daily. This is especially important in patients being treated with bisphosphonates; however, taking oral bisphosphonates should be separated from taking calcium by at least two hours, because the calcium can inhibit the absorption of the bisphosphonate. Patients with a history of kidney stones should discuss calcium and vitamin D intake with their physicians.

Exercise is  most important in maintaining skeletal health, avoiding weight gain, and maintaining joint mobility. Since undue stress on affected bones should be avoided, patients should discuss any exercise program with their physicians before beginning.
Prognosis:
The outlook is generally good, particularly if treatment is given before major changes in the affected bones have occurred. Any bone or bones can be affected, but Paget’s disease occurs most frequently in the spine, skull, pelvis, femur, and lower legs. In general, symptoms progress slowly, and the disease does not spread to normal bones. Treatment can control Paget’s disease and lessen symptoms, but is not a cure. Osteogenic sarcoma, a form of bone cancer, is an extremely rare complication that occurs in less than one percent of all patients.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose

Resources:
http://en.wikipedia.org/wiki/Paget’s_disease_of_bone
http://www.bbc.co.uk/health/physical_health/conditions/pagets1.shtml
http://www.endotext.org/parathyroid/parathyroid15/parathyroid15.html
http://www.mayoclinic.com/health/pagets-disease-of-bone/DS00485
http://www.surgeongeneral.gov/library/bonehealth/chapter_3.html
http://www.sciencephoto.com/media/260576/enlarge

Enhanced by Zemanta

Bone Scan

Alternative Names:Scintigraphy – bone

Definition:
The process of bone growth and renewal is part of your body’s metabolism — natural processes that create and use energy.

Changes in your bone metabolism can be caused by a number of problems. To get a picture of your bone metabolism, your doctor may order a procedure called a bone scan. A radiologist will look for evidence of abnormal metabolism on images from your bone scan.

CLICK & SEE

Your doctor may order a bone scan to help diagnose subtle or hidden bone fractures, such as a stress fracture, that may not show up on a routine X-ray. Bone scans can also help detect other conditions as well. It is a test that detects areas of increased or decreased bone metabolism (turnover). The test is performed to identify abnormal processes involving the bone such as tumor, infection, or fracture.
…...Nuclear Scan->
This is a nuclear scan, also called a radionuclide scan. In a bone scan, a radioactive tracer accumulates in places in your bones with a lot of repair activity. In this way, the tracer is used to identify areas that might be injured due to a fracture, bone infection, arthritis, or invading cancer. The tracer gives off gamma rays, which can be detected using a specialized camera. The camera relays information to a computer to produce images of the bones being scanned. In the images, bright spots appear in the areas where the tracer has collected. Bone scans are most frequently done for people with cancer to see if the cancer has spread to bones.

Why Bone Scan is Done:
Your doctor may order a bone scan to determine whether you have any bone abnormalities that may signify one of the following disorders:

*Fractures
*Arthritis
*Paget’s disease of bone
*Bone tumors
*Infection of the joints, joint replacements or bone (osteomyelitis)
*Fibrous dysplasia
*Avascular necrosis or impaired bone blood supply
*Unexplained bone pain

Your doctor may order a bone scan to determine whether cancer, such as prostate, lung or breast cancer, has spread (metastasized) to bone.

How the Test is Performed
A radiotracer (a bone-seeking radioactive material) is injected into vein, so it travels through the bloodstream. As the material wears away, it gives off radiation. This radiation is detected by a camera that slowly scans your body. The camera takes pictures of how much radiotracer collects in the bones.

If a bone scan is done to see if you have a bone infection, images will be taken shortly after the radioactive material is injected, as well as 3 to 4 hours later, when it has collected in the bones. This is called a 3-phase bone scan.

To evaluate metastatic bone disease, images are taken only after the 3 to 4 hour delay.

The scanning part of the test will last about 1 hour and may require you to change positions.

How do you prepare for the test?
No special preparation is required on your part before a bone scan, though you may be asked to remove jewelry or other metal objects. You can eat or drink anything you like before the test.

As with most tests, tell your doctor if you’re pregnant or think you might be pregnant. Bone scans aren’t usually performed on pregnant women because of concerns about radiation exposure to the fetus. You may be asked to wear a hospital gown.

What happens when the test is performed?
The test is performed in the radiology department of a hospital. You will be given a radionuclide. A machine with a specialized camera moves around you. The procedure is painless, but the machine can be noisy. The scan usually takes less than an hour.

There is a small amount of pain when the needle is inserted. During the scan there is no pain. You must remain still during the examination, and you will be instructed when to change positions by the technologist.

You may experience some discomfort due to lying still for a prolonged period of time.

Risk Factor.
The radioactivity you are exposed to is too small to cause side effects or complications except to a fetus. The small amount of radioactivity rapidly diminishes.If you are pregnant or nursing, the test may be postponed to prevent exposing the fetus to radiation.

The amount of radioactivity in the injection is very small, and virtually all activity is gone from the body within 2-3 days.

Although it is extremely rare with bone scanning agents, a person may develop rash, swelling, or anaphylaxis (severe allergic response).

There is a slight risk of infection or bleeding with any intravenous injection. The risk of an allergic reaction to the tracers is extremely rare.

You might find the injection and the need to lie still during the scanning procedure mildly uncomfortable.

Must you do anything special after the test is over?
Nothing.

How long is it before the result of the test is known?
Results are usually available within a few days.

What you can expect
A bone scan falls under the category of nuclear medicine procedures, which means that it uses tiny amounts of radioactive materials called tracers (radionuclides). These tracers accumulate in certain organs and tissues, such as bones. Once introduced into the body, tracers emit a type of radiation called gamma waves, which are detected by a special camera. This camera produces images that are interpreted by radiologists or nuclear medicine specialists.

In a sense, a nuclear procedure such as a bone scan is the opposite of a standard X-ray examination. An X-ray passes radiation into or through your body to create an image on film placed on the other side of your body. In a nuclear scan, the source of radiation is inside your body and travels to the surface, where a camera detects it.

A bone scan can be divided into two basic parts:

*The injection. You will receive an injection of tracers into a vein in your arm, and depending on the reason your doctor orders the scan, images of the injection may be taken immediately. You’ll then wait between two and four hours to allow the tracers to circulate and be absorbed by your bones. You may be allowed to leave the radiology department during this time. Your doctor will ask you to drink extra water to remove unabsorbed radioactive material from your system.

*The scan. During the scan, you’ll be asked to lie still on a table while a machine with an arm-like device supporting the gamma camera passes over your body to record the pattern of tracer absorption by your bones. This is painless. A scan of your entire skeleton takes as long as 60 minutes. Scanning a limited area of your body takes less time.
In some cases, your doctor might order a three-phase bone scan, which includes a series of images taken at different times. A number of images are taken as the tracer is injected, then shortly after the injection, and again three to four hours later.

For certain conditions your doctor might also order additional images called single-photon emission computerized tomography (SPECT). This can help analyze conditions that are especially deep in your bone or in places that are difficult to see with static or two-dimensional (planar) images. The additional SPECT images take approximately 30 minutes.

After the test
Once inside your body, the tracers don’t remain active for long. The radioactivity is eliminated within two days. You should feel no side effects after the procedure, and no aftercare is necessary.

Results:
The radiologist looks for evidence of abnormal bone metabolism on the scans. These show up as darker “hot spots” and lighter “cold spots” where the tracers have or haven’t accumulated.

Although a bone scan is very sensitive to abnormalities in bone metabolism, it’s less helpful in determining the exact cause of the abnormality. However, a thorough medical history often reveals the cause, such as a suspected fracture, infection or bone tumor. Other tests may be performed to help establish the diagnosis. For instance, in order to rule out bone cancer, your doctor may need further imaging studies (computerized tomography or magnetic resonance imaging) or a biopsy, which is a sample of bone tissue that’s removed for examination.
Normal Results
Normal distribution areas appear uniform and gray throughout all the bones in your body.

What Abnormal Results Mean
The images should show that the radioactive material has been evenly distributed throughout the body. There should be no

areas of increased or decreased distribution. “Hot spots” are areas where there is an increased accumulation of the radioactive material. “Cold spots” are areas that have taken up less of the radioactive material.

Resources:
https://www.health.harvard.edu/diagnostic-tests/bone-scan.htm
http://www.mayoclinic.com/health/bone-scan/
http://www.nlm.nih.gov/medlineplus/ency/article/003833.htm

Enhanced by Zemanta