Bone Infection in the Diabetic Foot (Osteomyelitis)
How is bone infection (osteomyelitis) in a diabetic foot wound recognised, which tests are done, and is treatment without surgery possible?
Short answer
Osteomyelitis is a bone infection that develops when bacteria reach the bone from a deep foot wound. It is considered in wounds that have not closed for months, that extend to the bone, or that close and open again. Diagnosis uses examination, blood tests, X-ray and, if needed, MRI. In selected patients it is treated with a long course of antibiotics, in others by surgically removing the infected bone; not every bone infection means amputation.
Osteomyelitis is infection of the bone. In the diabetic foot it almost always develops when a deep wound reaches the bone; bacteria pass from the wound into the neighbouring bone. The toe bones, the heads of the metatarsal bones and the heel bone are affected most often. It is one of the important reasons why a wound stays open for a long time and keeps coming back.
When is it considered?
- The wound extends to the bone, or bone can be seen or felt in the wound
- The wound has not healed for weeks or months despite appropriate care
- After closing, the wound opens again in the same place
- The toe is swollen and red along its whole length ("sausage toe")
- Small fragments of bone come out of the wound
- The X-ray shows bone loss or irregularity
Bone infection can run its course without pain, and the wound on the surface can look small. For this reason the threshold of suspicion is kept low.
How is it diagnosed?
No single test is enough; the findings are interpreted together.
- Examination: The base of the wound is checked with a sterile, blunt instrument. If the instrument touches bone, the likelihood of bone infection increases.
- Blood tests: Raised markers such as sedimentation rate and CRP support the diagnosis and are used to follow the response to treatment.
- X-ray: This is the first imaging method. It can be normal in the early stage; repeating it a few weeks later is informative.
- MRI: It is requested when a decision cannot be reached with X-ray and examination, or to show the extent of the infection when surgery is being planned.
- Bone sample: Culture and pathological examination of a sample taken from the bone is the most reliable method. It shows which bacterium is responsible and which antibiotic will be effective.
Treatment options
There are two main routes, and they are often used together.
| Mainly antibiotics | Surgery and antibiotics | |
|---|---|---|
| Who it is considered for | Limited involvement (for example a single bone in the forefoot), adequate blood flow, no extensive tissue death | Extensive bone involvement, abscess, tissue death, joint involvement, no response to antibiotics |
| What is done | A culture-based antibiotic that penetrates bone well | Removal of infected and dead bone, followed by antibiotics |
| Duration | About 6 weeks according to guidelines | Clearly shorter if all of the infected bone has been removed |
Which route is chosen depends on the location and extent of the infection, the blood flow to the foot, and the patient's general condition and preference. Surgery does not always mean amputation: in most cases only the infected part of the bone is removed and the foot is preserved.
The other parts of treatment are just as important:
- Restoring blood flow: If circulation is inadequate, the antibiotic cannot reach the bone; a vascular assessment is needed.
- Offloading: Weight is kept off the infected area.
- Wound care and blood sugar control.
How is the response to treatment followed?
Closure of the wound, swelling and redness settling, and blood markers falling are favourable signs. In bone infection, follow-up continues after treatment has ended before saying that it has healed, because recurrence can appear months later. If the wound reopens, or discharge or swelling is noticed during this period, care should be sought without waiting.
When should a second opinion be considered?
If amputation has been recommended because of bone infection and the situation is not urgent, getting a second specialist opinion before the decision is a reasonable step. The true extent of the infection, whether blood flow has been assessed, and whether a more limited operation is possible can be reviewed again.
Assessment in Istanbul
In bone infection, the choice, dose and duration of the antibiotic directly affect the success of treatment. Prof. Dr. Aytaç Çetinkaya is a specialist in Infectious Diseases and Clinical Microbiology; orthopaedic infections and diabetic foot infections are his main fields of work. Patients in Türkiye and international patients can send their MRI and X-ray reports, culture results and a photo of the wound on WhatsApp to ask for a preliminary review. A preliminary review does not replace an examination.
Frequently asked questions
Does bone infection always mean amputation?
Is an X-ray enough for diagnosis?
How long does antibiotic treatment last?
The wound has closed. Is the bone infection gone?
My toe has swollen up like a sausage. What does this mean?
References
This page is for general information only and does not replace an examination, diagnosis or treatment. In an emergency, call your local emergency number or go to the nearest emergency department.