This single copy is for your personal, noncommercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, use the reprints link below.

· Order reprints of this article now.

Osteomyelitis

Definition

Osteomyelitis is the medical term for an infection in a bone. Infections can reach a bone by traveling through your bloodstream or spreading from nearby tissue. Infections can also begin in the bone itself if trauma exposes your bone to germs. Bone infections commonly affect the long bones of your body, such as your leg bones and upper arm bone, as well as your spine and pelvis.

Osteomyelitis often occurs in children as an acute condition. In adults, osteomyelitis may occur as either the acute and chronic form.

Once considered incurable, osteomyelitis can be successfully treated today. Still, osteomyelitis is a serious condition, requiring aggressive treatment to prevent spread of your infection and to save the affected bone.

Symptoms

Signs and symptoms of osteomyelitis depend on whether the condition is acute, lasting several months or less, or chronic, lasting several months to years.

Signs and symptoms of acute osteomyelitis include:

• Fever that may be abrupt
• Irritability or lethargy in young children
• Pain in the area of the infection
• Swelling, warmth and redness over the area of the infection

Signs and symptoms of chronic osteomyelitis include:

• Warmth, swelling and redness over the area of the infection
• Pain or tenderness in the affected area
• Chronic fatigue
• Drainage from an open wound near the area of the infection
• Fever, sometimes

Sometimes osteomyelitis causes no signs and symptoms or has signs and symptoms that are difficult to distinguish from other problems. For instance, osteomyelitis of the hip, spine or pelvis may have few signs and symptoms. Osteomyelitis that occurs after a broken bone (fracture) or deep wound may cause pain and swelling that you may attribute to your injury, not an infection.

Causes

Osteomyelitis occurs when an infection develops in a bone or spreads to a bone from another area of your body. It's caused by bacteria or fungi. The infected bone may deteriorate and form a pocket (abscess) of pus in response to the infection. This may block blood supply to the bone. In cases of chronic osteomyelitis that last for years, the loss of blood supply may lead to death of the bone.

Your bones are normally resistant to infection. In order for osteomyelitis to occur, a situation that makes your bones vulnerable must be present. For instance, trauma to your bone, such as a fracture, or to the soft tissue around your bone, such as a puncture wound, gives infections a route to enter your bone or nearby tissue. You may also be vulnerable to infection if you have a condition that weakens your body's ability to fight an infection, such as HIV, diabetes or sickle cell anemia.

Osteomyelitis is divided into several types depending on where an infection begins and where it occurs. Types of osteomyelitis include:

• Infections that travel through the bloodstream. Infections that travel through the bloodstream (hematogenous osteomyelitis) affect only a small portion of adults, but affect the majority of children with osteomyelitis. Infections may begin as mild infections elsewhere in the body, such as an upper respiratory tract infection or urinary tract infection, and spread through the blood to a bone.
• Infections that occur after injury or surgery. Bone infections can occur after trauma (post-traumatic osteomyelitis), such as broken bones that break the skin (compound fracture) or open wounds to the surrounding skin and muscles. Post-traumatic osteomyelitis can also occur after surgery if metal pins, screws or plates are used to secure the broken bones. Open wounds offer easy access for bacteria to enter the bone or nearby tissue directly.
• Infections in people with poor circulation. Osteomyelitis that occurs in people with poor circulation, such as those with diabetes, usually begins with minor scrapes or cuts on the feet. Poor circulation (vascular insufficiency) impairs the body's response to infection. What begins as a small cut can progress to a deep ulcer that may expose deep tissue and bone to infection.
• Infection in the bones of the spine. Osteomyelitis that occurs in the spine (vertebral osteomyelitis) most commonly affects older adults and usually starts with an infection in the bloodstream, though it can also occur from trauma or surgery (post-traumatic osteomyelitis). A number of infections can cause vertebral osteomyelitis, including skin infections, respiratory tract infections, urinary tract infections, infections in the inner lining of the heart (endocarditis), infections in the mouth, and infections in areas where you receive drug injections.

Risk factors

Osteomyelitis occurs more often in men than in women. People of any age can develop osteomyelitis, though the acute form tends to be more common in children, and people older than 50 are more likely to have the spinal form of the infection.

You also have an increased risk of osteomyelitis if you have:

• An increased risk of infections. Certain situations allow germs more opportunities to access your body, putting you at an increased risk of infection, which can lead to osteomyelitis. Examples include people who illegally inject drugs, people on dialysis, people who use urinary catheters and people who have had tubes placed in their bodies to give doctors easier access to major veins (central lines).
• Poor circulation. People with poor circulation include those with diabetes, peripheral arterial disease and sickle cell disease. When the arteries are damaged or blocked, your body has difficulty distributing the infection-fighting cells needed to keep a small infection from growing larger.
• A recent injury. A broken bone that breaks the skin or a deep puncture wound exposes your body to germs that can cause infection and increase your risk of osteomyelitis. Carefully follow your doctor's instructions on taking antibiotics and taking precautions to prevent infection.
• Orthopedic surgery. Surgery to repair broken bones or replace worn joints puts you at risk of infection. Follow your surgeon's instructions to help avoid infection after your surgery.

When to seek medical advice

See your doctor if you experience worsening bone pain along with signs and symptoms of an infection, such as fever and chills. If you're at risk of infection because of a medical condition or recent surgery or injury, see your doctor right away if you notice signs and symptoms of an infection.

Tests and diagnosis

Your doctor conducts a physical exam to better understand your signs and symptoms if he or she suspects you may have osteomyelitis. Your doctor may feel the area around the affected bone for any tenderness, swelling or warmth.

Your doctor may order a combination of tests and procedures to diagnose osteomyelitis and to determine what type of infection you have, including:

• Blood tests. Blood tests may reveal elevated levels of white blood cells and other factors that may indicate that your body is fighting an infection. If your osteomyelitis was caused by an infection in the blood, tests may reveal what germs are to blame. No blood test exists that tells your doctor whether you do or do not have osteomyelitis. However, blood tests do give clues about your diagnosis, which your doctor uses to decide what further tests and procedures you may need.
• X-rays. X-rays can reveal damage to your bone. However, damage may not be visible until osteomyelitis has been present for several weeks. More-detailed imaging tests may be necessary if your osteomyelitis has developed more recently.
• Other imaging procedures. If your doctor can't get a clear picture of the affected bone using X-ray, he or she may order other imaging procedures, such as computerized tomography (CT), magnetic resonance imaging (MRI) or a bone scan.
• Bone biopsy. During a biopsy, a surgeon removes a small piece of your infected bone for analysis in a laboratory. The laboratory determines what type of bacteria or other pathogen is infecting your bone. Your doctor uses that information to determine your treatment. A biopsy can be performed as an open biopsy, meaning that it requires anesthesia and surgery to access the bone. In some situations, a surgeon inserts a long needle into your skin and your bone to take a biopsy (fine-needle aspiration). This procedure requires local anesthetics to numb the area where the needle is inserted.

Complications

The infection that causes osteomyelitis can usually be controlled. But a risk of recurrence always remains. Osteomyelitis that returns or continues undetected for years is considered chronic osteomyelitis. Chronic osteomyelitis can lead to the death of bone tissue and the collapse of the bone.

Osteomyelitis that can't be controlled may require drastic treatment in order to prevent spread to other parts of your body. When this occurs in arms and legs, drastic treatment may mean amputation of the affected limb.

Treatments and drugs

Doctors treat chronic osteomyelitis with surgery and antibiotics. In acute osteomyelitis in children or vertebral osteomyelitis, surgery isn't always necessary.

Surgery
What type of surgery you undergo for osteomyelitis depends on what bone is infected. Surgery may include one or more of the following procedures:

• Drain the infected area. Opening up the area around your infected bone allows your surgeon to drain any pus or fluid that has accumulated in response to the infection.
• Remove diseased bone and tissue. In a procedure called debridement, the surgeon removes as much of the diseased bone as possible, taking a small margin of healthy bone to ensure that all the infected areas have been removed. Surrounding tissue that shows signs of infection also may be removed.
• Restore blood flow to the bone. Your surgeon may fill any empty space left by the debridement procedure with a piece of bone or other tissue, such as skin or muscle, from another part of your body. Sometimes temporary fillers are placed in the pocket until you're healthy enough to undergo a bone graft or tissue graft. The graft helps your body repair damaged blood vessels and form new bone.
• Remove any foreign objects. In some cases, foreign objects, such as surgical plates or screws placed during a previous surgery, may need to be removed.

In order to stabilize the affected bone and the new graft, you may need to have metal plates, rods or screws inserted into the bone. This procedure is sometimes performed later. Your doctor may use other devices to stabilize your affected bone, such as external fixators.

People who can't tolerate surgery
Surgery as an osteomyelitis treatment isn't available to everyone. People who are very ill may not be able to endure the extensive surgery and recovery. In these cases, doctors may use antibiotics for longer periods of time, sometimes for years, in an attempt to suppress the infection, though cure generally isn't possible with this approach. If the infection persists, amputation of all or part of an infected arm or leg may be necessary.

Antibiotics
If your doctor suspects you have chronic osteomyelitis, he or she works to determine exactly what microorganism is causing the infection before prescribing antibiotics. Your doctor uses a bone biopsy or a piece of bone removed during surgical treatment to determine what's causing the infection.

Once the bacterium or fungus causing your infection has been identified and you've undergone surgery, if necessary, your doctor selects the antibiotic most likely to be effective in fighting your particular type of infection. Antibiotics are administered most often through a vein in your arm (intravenously) or, in some cases, they can be taken orally. You typically take antibiotics for four to six weeks, or even longer. In some cases, you may need to take antibiotics for the rest of your life.

Antibiotics carry a risk of side effects, including nausea, vomiting and diarrhea. Allergic reactions also can occur. Talk to your doctor about the side effects to expect from your specific medication.

Prevention

If you've been told that you have an increased risk of infection, talk to your doctor about ways to prevent infections from occurring. Reducing your risk of infection will also reduce your risk of developing osteomyelitis.

In general, be careful and take precautions to avoid cuts and scrapes, which give germs easy access to your body. If you do get any cuts and scrapes, clean the area immediately and apply a clean bandage. Check wounds frequently for signs of infection.

Lifestyle and home remedies

If you're undergoing treatment for osteomyelitis, take care of your body so that you have a better chance to fight the infection and heal. For instance:

• Stop smoking. If you smoke, quit. Smoking puts you at risk of many diseases and conditions. Smoking also slows blood flow to your hands and feet, making it even more difficult for your body to heal and fight infection.
• Eat a variety of fruits and vegetables. Give your body the support it needs to fight infection by eating a healthy diet with a variety of fruits and vegetables.
• Work to get control of your health. If you have diabetes or another disease or condition that affects your ability to fight infections, follow your doctor's instructions on medications and lifestyle modifications to help you better control your condition. Even if your osteomyelitis is controlled, continue following your doctor's instructions closely. This may help prevent osteomyelitis from returning in the future.