Overview
what it is and why it mattersOsteomyelitis is an infection inside a bone. It is almost always caused by bacteria (most often Staphylococcus aureus) and rarely by fungi or other germs. Bacteria reach the bone three main ways: through the bloodstream (most common in kids and older adults), from a nearby infection or open wound spreading inward, or after surgery on the bone. Once it becomes chronic, the infection leaves a piece of dead bone behind, and antibiotics alone usually cannot clear it. The dead bone has to be cut out surgically.
You are more likely to develop osteomyelitis if you have diabetes, poor circulation in your limbs, a weakened immune system (from medication or disease), a history of IV drug use, or a recent fracture or bone surgery.
Symptoms
what you may notice- Deep bone pain that worsens and won't settle, a constant ache in one spot that gets worse over days rather than better, and doesn't respond to typical pain relievers.
- Fever and chills, your body's systemic response to the infection, sometimes with night sweats.
- Redness, warmth, and swelling over the bone, the overlying skin may look inflamed even though the infection is inside the bone.
- Draining wound (sinus tract) if chronic, in long-standing cases, a small hole in the skin opens and drains pus intermittently, sometimes for months.
Diagnosis
exam first, imaging secondTwo blood markers of inflammation (ESR and CRP) are usually elevated, though they can rise from many different causes. Blood cultures and any wound cultures are drawn before antibiotics start so we can identify the exact germ. X-rays often look normal in the first week or two, because bone changes lag behind the infection. An MRI is far more sensitive: it shows fluid in the bone marrow and any abscess in the surrounding tissue. A nuclear medicine scan is a backup when MRI isn't an option. The gold-standard test is a bone biopsy (taken with a needle under CT guidance or in the OR), which tells the lab exactly which germ is involved and which antibiotics will kill it.
How We Treat It
what we try first, in orderTreatment is built around a long course of antibiotics, started once the lab tells us exactly which germ is involved. The steps below are introduced in order, each one building on the one before it.
1
IV Antibiotics
Care usually opens with several weeks of antibiotics given through a vein. The exact drug is picked once the lab identifies the germ and tells us which antibiotics it responds to, so the medicine is matched to the infection rather than guessed at.
2
Oral Antibiotics
After the IV phase, treatment continues with weeks to months of pills. The full course runs long because the goal is to clear the infection out of the bone completely, not just quiet the symptoms.
3
Working as a Team to Know When to Stop
Your surgeon and an infectious-disease specialist work together to decide when you can stop. That call is based on how your symptoms, your blood markers, and your imaging respond over the course of treatment.
Surgical Options
if non-operative care isn't enoughSurgery is needed for chronic osteomyelitis, infections that have grown around prior hardware (plates, screws, joint replacements), or acute infections that aren't getting better on antibiotics. The operation has three parts: cut out the dead, infected bone and any infected hardware; fill the empty cavity with antibiotic-loaded cement or bone graft so it doesn't collapse; and cover the wound with healthy soft tissue (often with a plastic surgeon) to give the bone a clean blood supply.
Frequently Asked
questions we hear in clinicWhat causes osteomyelitis?
It is almost always caused by bacteria, most often Staphylococcus aureus, and rarely by fungi or other germs. The bacteria reach the bone three main ways: through the bloodstream (most common in kids and older adults), from a nearby infection or open wound spreading inward, or after surgery on the bone.
Who is most at risk?
You are more likely to develop osteomyelitis if you have diabetes, poor circulation in your limbs, a weakened immune system (from medication or disease), a history of IV drug use, or a recent fracture or bone surgery.
How is it diagnosed?
Two blood markers of inflammation, ESR and CRP, are usually elevated, though they can rise from many causes. Blood and wound cultures are drawn before antibiotics start so we can identify the exact germ. X-rays often look normal in the first week or two because bone changes lag behind the infection, so an MRI is used because it is far more sensitive. The gold-standard test is a bone biopsy, which tells the lab exactly which germ is involved and which antibiotics will kill it.
Why does the antibiotic course take so long?
Treatment is typically several weeks of IV antibiotics first, then weeks to months of pills. The full course runs long because the goal is to clear the infection out of the bone completely, not just quiet the symptoms. Your surgeon and an infectious-disease specialist decide when you can stop, based on how your symptoms, blood markers, and imaging respond.
Why can't antibiotics alone cure a chronic case?
Once the infection becomes chronic, it leaves a piece of dead bone behind. Antibiotics alone usually cannot clear that, so the dead bone has to be cut out surgically.
When is surgery needed?
Surgery is needed for chronic osteomyelitis, infections that have grown around prior hardware such as plates, screws, or joint replacements, or acute infections that aren't getting better on antibiotics. The operation removes the dead, infected bone and hardware, fills the empty cavity so it doesn't collapse, and covers the wound with healthy soft tissue.
Providers Who Treat Osteomyelitis
trauma team
Further Reading
authoritative sourcesExternal patient-education references and related OSI pages for additional background: