 |
|
|||||||||
May 23, 2006
Osteomyelitis: Symptoms & Treatment
by SirGan
 Osteomyelitis is an infection of bone, usually caused by pyogenic bacteria or mycobacteria. It can be usefully sub-classified on the basis of the:
In rare circumstances bone and joint infections can be even fatal, but, luckily-early diagnosis and proper treatment can help control or eliminate the infection.
IncidenceThe incidence of osteomyelitis is 2 in 10,000 people. Neonatal prevalence is approximately 1 per 1,000. The annual incidence in sickle cell patients is approximately 0.36%. The prevalence of osteomyelitis after foot puncture may be as high as 16%. 30-40% of all patients are diabetics. Male-to-female ratio is approximately 2:1.
The route of infectionSeveral researches done in the past have proven that bacteria can infect bones in a number of ways. The most common bacterium that causes osteomyelitis is Staphylococcus aureus!
Possible causes of osteomyelitisBeside the Staphylococcus aureus, Escherichia coli, and streptococci are other common pathogens. In some subpopulations, including intravenous drug users, Gram negative bacteria, including enteric bacilli, are significant pathogens. In osteomyelitis involving the vertebral bodies, 50 percent of the cases are due to Staphylococcus aureus, and the other 50 percent due to tuberculosis.
The infection that causes osteomyelitis often is in another part of the body and spreads to the bone via the blood. Affected bone may have been predisposed to infection because of recent trauma.
Usually, when we are talking about children’s osteomyelitis- the long bones are affected, while, in adults, the vertebrae and the pelvis are most commonly affected. When the bone is infected, pus is produced within the bone, which may result in an abscess. The abscess then deprives the bone of its blood supply. Chronic osteomyelitis results when bone tissue dies as a result of the lost blood supply. Chronic infection can persist intermittently for years.
Signs and symptoms of osteomyelitisThe signs and symptoms of osteomyelitis and septic arthritis vary depending on the location of the infection, the stage to which it has developed and the cause of the infection.
Hematogenous long-bone osteomyelitis
Hematogenous vertebral osteomyelitis
Chronic osteomyelitis
All this is usually accompanied with fever, edema, warmth, fluctuance, tenderness to palpation, reduction in the use of the extremity and sinus tract drainage. When we are talking about histological changes, then we should mention that bone necrosis is the basic process! These areas of necrotic bone are the basis for distinguishing between acute osteomyelitis and chronic osteomyelitis. Osteomyelitis is an infective process which encompasses all of the bone components, including the bone marrow. When it is chronic it can lead to bone sclerosis and deformity.
Risk factorsRisk factors are:
Diagnosis of osteomyelitis
An increased number of white blood cells in your blood may indicate infection. Your doctor also may be able to identify the infecting microorganism in cultures of your blood.
Bone scans and X-ray exams are the key to diagnosing osteomyelitis and may help your doctor identify the infected areas. For example, they may help detect fluid collections around a joint and abnormal bone surfaces. These methods can be particularly useful in diagnosing septic arthritis, since they can better define soft tissue swelling and identify excess fluid in an infected joint.
The gold standard for diagnosing a bone or joint infection is biopsy. Your doctor will usually administer a local anesthetic and remove tissue from a bone lesion or use a needle to withdraw fluids from an infected joint. Tests, including cultures performed on the samples, can confirm an infection and identify its cause.
The MRI is effective in the early detection and surgical localization of osteomyelitis. Studies have shown its superiority compared with plain radiography, CT, and radionuclide scanning in selected anatomic locations. Its sensitivity ranges from 90-100%.
CT scans can depict abnormal calcification, ossification, and intracortical abnormalities. It probably is most useful in the evaluation of spinal vertebral lesions. It may also be superior in areas with complex anatomy: pelvis, sternum, and calcaneus.
This simple and inexpensive technique has shown promise, particularly in children with acute osteomyelitis. Ultrasonography may demonstrate changes as early as 1-2 days after onset of symptoms. Abnormalities include:
Ultrasonography allows for ultrasound-guided aspiration. It does not allow for evaluation of bone cortex.
In order to set the accurate diagnosis- it requires 2 of the 4 following criteria:
Possible complicationsSeveral problems could occur if osteomyelitis is left untreated. In most cases- it is becoming a chronic infection or spread to other areas of your body, eventually causing bone death. This process is called osteonecrosis. Reduced limb or joint function can result, and in extreme cases this may require amputation. It can even damage spinal nerves and even prove fatal. The most common complication of septic arthritis is osteoarthritis-inflammation of bone and joint. Some patients may have a poor long-term response to joint infection treatment so it can lead sometimes to permanent movement limitation, difficulty walking or shortening of the afflicted limb.
Other possible complications include:
Complications:
Treatment of osteomyelitisThere are several treatment options for treating osteomyelitis and septic arthritis and the primary goal should be eliminating the infection and prevent it from developing into a chronic condition.
If the infection is caused by bacteria, it's often treated with antibiotics.
Your doctor may drain soft tissue abscesses — or pockets of fluid — surrounding infected bones or joints, as needed. If you have septic arthritis, your doctor may use a needle to drain pus from the joint on a daily basis. It can also use an instrument called arthroscope to clean the joint. If the infection is serious and couldn’t be resolved by drainage-he may need to open the joint surgically to remove damaged tissue and infection.
Surgery is usually necessary, especially if the infection is chronic or if a patient have some hardware implanted such as metal plates or artificial joints.
PreventionThe easiest way to prevent your-self from getting osteomyelitis is to practice good hygiene. This means that, if you get a cut or a wound make sure you clean it thoroughly. Wash it with simple toilet soap and water, holding it under running water for at least 5 minutes to flush it out.
To keep the wound clean afterward, you should cover it with sterile gauze or a clean cloth. You can apply an over-the-counter antibiotic cream, too, but the most important thing is to keep the injury clean.
|
|
|||||
|
Article sources
|
