Like other parts of the body, your bones can become infected — a condition known as osteomyelitis. There are two major types of bone infections: acute osteomyelitis and chronic osteomyelitis.
Both types of osteomyelitis can occur throughout your body, and both can be caused by either bacteria or fungi. But they come from different sources.
Acute osteomyelitis usually occurs when an infection enters your bloodstream and then gets into the bone. When pathogens from chronic injuries or ulcers get directly into the underlying bone, it’s called chronic osteomyelitis.
What Is Chronic Osteomyelitis?
Chronic osteomyelitis is an infection that happens as a result of a chronic or unhealed wound or ulcer. They are common in people with chronic conditions like diabetes, obesity, and peripheral artery disease.
Other factors that could lead to chronic bone infections include:
- Injuries (such as open fractures).
- Hardware from surgical procedures.
- Acute bone infections that don’t properly heal.
- Intravenous drug use.
“There are a lot of risk factors associated with bone and joint infections, including things like obesity, diabetes, a weakened immune system, and injection drug use,” says Neel Shah, MD, infectious disease specialist, UPMC. “As these risk factors become more common, the incidence of bone and joint infections are increasing across the country.”
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How Does Chronic Osteomyelitis Happen?
Common bacteria that live on your skin include strep or staph. These bacteria and others can form in the area of a chronic wound and then spread to your bone.
“The opening of the skin over the bone colonizes with different types of bacteria,” Dr. Shah says. “Over time, as the wound or ulcer gets deeper and deeper, the bacteria are able to progress down deeper into the underlying bone.”
The process of chronic osteomyelitis doesn’t happen quickly. It can take weeks, months, or even years for a chronic bone infection to form.
“It depends on the progression of the erosive changes involving the wound or the ulcer that’s present,” Dr. Shah says. “It can take quite some time. Infection can develop faster in individuals with risk factors, or if a wound is chronically neglected over time. For individuals who minimize the risk factors for infection by controlling their diabetes, avoiding injection drugs, managing their peripheral arterial disease, and getting routine wound care, the risk for developing chronic osteomyelitis is much less likely.”
Chronic Osteomyelitis Symptoms
Because chronic osteomyelitis occurs slowly, symptoms may be less obvious than those for acute osteomyelitis. For example, fever is a common symptom of acute osteomyelitis but a less common symptom for chronic osteomyelitis. Someone with a chronic bone infection also may have a normal white blood cell count.
“With chronic osteomyelitis, patients don’t tend to really look sick until the infection enters into the bloodstream from the bone, or the wound becomes extensively infected,” Dr. Shah says.
The most common symptoms of chronic bone infections include pain, redness, and swelling in the affected area.
Chronic wounds that fail to heal — even with proper care — are also a possible sign of a chronic bone infection. Draining wounds, especially with pus, and exposed bones also can indicate bone infections.
Tests that can help diagnose bone infections include x-rays, MRIs, and biopsies of the affected bone. No single test is definitive in diagnosing osteomyelitis.
Chronic Osteomyelitis Treatment
Treatment for chronic bone infections typically includes surgical debridement of the affected bone and tissue area, as well as antibiotics.
If the surgeon has to remove a large amount of bone and tissue, they may need to use tissue grafting to fill in the empty space.
Dr. Shah says with quick and proper diagnosis and treatment, most patients recover from bone infections. But if diagnosis and treatment don’t happen until it’s too late, it can lead to complications which may require amputation. If the infection spreads to a nearby joint, it can cause infection and septic arthritis in that joint. Skin cancer is also a rare complication from draining wounds.
Your overall health also can affect your recovery. People who are older, who smoke or drink, or who have a weakened immune system or a condition like diabetes or obesity may have slower recovery times.
“There are a number of factors that play a role,” Dr. Shah says. “Generally, outcomes are good, but based on these factors, recovery may be delayed or incomplete.”
Can You Prevent Chronic Bone Infections?
Dr. Shah says most bone infections are preventable.
Proper management of underlying health conditions like diabetes and peripheral artery disease can help prevent chronic osteomyelitis. Proper wound control — keeping your skin clean and avoiding chronic wounds, rashes, and injuries — also can help.
It is also important to maintain good health by following a healthy diet and avoiding smoking, drinking, and injection drug use.
Because of the potential of complications from chronic osteomyelitis, it’s important to call your doctor if you experience any symptoms.
The UPMC Center for Care of Infectious Diseases provides expert multidisciplinary care. For more information or to make an appointment, call 412-647-7228 or 1-877-788-7228.
About Infectious Diseases
If you have a disease caused by bacteria, fungi, parasite, or virus, the UPMC Center for Care of Infectious Diseases can help. Our team of experts is specially trained in the prevention and treatment of infectious diseases, including of HIV-AIDs, postsurgical and transplant infections, illnesses caused by international travel, and more. We research infectious diseases and participate in clinical trials to learn more and develop better treatment and prevention methods. Visit our website to find an expert near you.