How does a foot ulcer turn into a bone infection?

In diabetes, reduced sensation and poor circulation let a wound go unnoticed and heal slowly, so bacteria can spread deeper until they reach the bone. A foot ulcer that is not healing, or one that can be probed down to bone, is a warning sign of possible osteomyelitis.

Can osteomyelitis be cured with antibiotics alone?

Some cases – caught early, before bone is destroyed – can be cured with antibiotics alone, but many need surgery as well to remove infected or dead bone. The right approach depends on how far the infection has progressed.

Why does treatment take so long?

Bone has a limited blood supply, so antibiotics reach it less easily than soft tissue, meaning infections need weeks of treatment – sometimes starting with intravenous antibiotics before switching to tablets.

Is osteomyelitis dangerous?

Yes, it is a serious infection. If untreated it can become chronic, cause areas of bone to die, spread to nearby joints, and in severe diabetic foot cases can lead to amputation – which is why early treatment matters.

I have diabetes and a wound on my foot that isn’t healing – what should I do?

See a doctor promptly rather than waiting. Early assessment and coordinated foot and wound care greatly reduce the risk of the infection reaching the bone and of losing part of the limb.

Osteomyelitis (Bone Infection) Singapore

Written & reviewed by the BestDoctors.sg editorial team · Last updated 2 Sep 2026 · General information, not medical advice

Quick answer. Osteomyelitis is an infection of the bone, most often caused by bacteria (commonly Staphylococcus aureus), which can reach the bone through the bloodstream, from a nearby infection, or through an open wound, injury or surgery. It is especially relevant in people with diabetes, where a foot ulcer can let infection spread into the bone, and it usually needs a prolonged course of antibiotics and often surgery to remove infected or dead bone.

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In a medical emergency, or for severe or sudden symptoms such as breathing difficulty, chest pain, fainting or stroke signs, call 995 immediately.

The Singapore-relevant warning: in a person with diabetes, a non-healing foot wound – or one that can be probed down to bone – is a red flag for bone infection. See a doctor promptly rather than waiting.

Red flags – act now. See a doctor urgently, the same day, if you have increasing bone or deep pain with redness, warmth, swelling or fever; a wound that is not healing or is discharging – especially a foot wound if you have diabetes; or you simply feel generally very unwell.

Go to A&E or call 995 for signs of serious infection or sepsis: a high fever with shivering, confusion or drowsiness, a very fast heartbeat, or feeling very unwell. Do not delay, especially if you have diabetes.

What osteomyelitis is

Osteomyelitis is an infection of the bone, usually caused by bacteria and most often by Staphylococcus aureus. It is uncommon, but it is serious and needs prompt treatment, because an untreated bone infection can damage and destroy the bone and spread to other parts of the body. Once bacteria take hold, the resulting inflammation can cut off the blood supply to part of the bone, so areas of bone die and become difficult for antibiotics to reach.

Doctors describe osteomyelitis as either acute or chronic. Acute osteomyelitis comes on quickly, over days, and often responds well when treated early. Chronic osteomyelitis is long-standing or keeps coming back; it can smoulder for a long time, sometimes with a persistent draining wound, and it usually needs more prolonged and combined treatment.

How germs reach the bone

Bacteria can reach bone by three main routes:

Through the bloodstream – germs from an infection elsewhere in the body (for example the skin, chest or urinary tract) travel in the blood and settle in a bone.
Spreading from a nearby infection or wound – an infection in the tissue next to a bone extends inwards. This is a common route in adults.
Directly from an injury, surgery or a deep wound – germs are introduced through an open fracture, an operation involving bone or metal implants, or a deep wound such as a diabetic foot ulcer.

Symptoms

The features of a bone infection can include:

Bone or deep pain and tenderness over the affected area.
Redness, warmth and swelling over the site (redness may be harder to see on darker skin).
Fever and chills.
Feeling generally unwell and tired.
In chronic cases, a persistent draining wound or sinus – a small skin opening that leaks fluid or pus.

Importantly, in some people – especially those with diabetes and reduced sensation in the feet – pain may be much less obvious. A wound draining pus, or an ulcer that will not heal, can be the main clue even when there is little pain. Do not use the absence of pain to reassure yourself.

Who is at higher risk

Anyone can develop osteomyelitis, but the risk is higher with:

Diabetes, particularly when there are foot ulcers.
Poor circulation (peripheral vascular disease), which slows healing.
A weakened immune system.
Recent bone surgery, or a prosthetic joint or metalwork in the body.
Injecting drug use.
Open fractures or deep wounds.
Being very young or an older adult.

A previous episode of osteomyelitis also makes a further episode more likely.

The diabetic foot connection

In diabetes a foot wound can be the doorway to a bone infection – a major and very relevant problem in Singapore given how common diabetes is. Reduced sensation means an injury or ulcer may go unnoticed, while poor circulation slows healing, so a small wound can deepen until it reaches bone. A non-healing foot ulcer, or one a clinician can “probe to bone,” strongly suggests osteomyelitis. This is why daily foot checks and prompt attention to any non-healing wound matter so much, alongside coordinated “limb salvage” care that brings together several specialists.

How it is diagnosed

No single test proves a bone infection, so doctors combine several:

Blood tests that look for signs of infection and inflammation, and blood cultures to look for bacteria.
Imaging – X-rays (which may look normal early in the illness), MRI (very useful for detecting bone infection), and bone scans.
Most importantly, taking a sample of bone or fluid for culture, to identify the exact germ and its sensitivities. This guides the choice of antibiotic so treatment is targeted rather than guessed.

In diabetic foot infections, the bedside “probe-to-bone” test also helps support the diagnosis.

Treatment

Osteomyelitis is treated by a specialist team, and treatment usually has two parts.

First, a prolonged course of antibiotics. These are often started into a vein in hospital and may later be switched to tablets, and the course is typically continued for an extended period to clear infection from bone.

Second, surgery, which is needed in many cases. An operation can drain collections of infection and remove dead or infected bone – this is called debridement – and can treat the source of the problem, such as a foot ulcer or an infected implant. Alongside this, managing the underlying cause matters: careful diabetic foot care, good blood-sugar control, and improving circulation all help the infection settle and reduce the chance of it returning. An orthopaedic surgeon and an infectious disease team usually lead care together.

Complications if untreated

Left untreated, or treated late, osteomyelitis can lead to serious problems:

Bone destruction, with areas of bone dying.
Chronic infection that keeps returning and is harder to cure.
Spread to the bloodstream or to nearby joints.
In severe diabetic foot cases, risk to the limb, including the possibility of amputation.

This is exactly why early assessment and treatment matter so much.

Recovery and follow-up

Recovery depends on completing the full course of antibiotics even after you start to feel better, on careful wound care, and on monitoring by the team to check the infection is clearing. Acute osteomyelitis that is caught and treated early frequently clears completely. Chronic osteomyelitis can need long-term care, sometimes with more than one operation and repeated review, and ongoing attention to the underlying cause such as circulation and diabetes control.

Prevention

You cannot prevent every case, but you can lower the risk:

Treat wounds and skin infections promptly and keep them clean, rather than letting them linger.
Practise good diabetic foot care – daily checks, well-fitting footwear, and early review of any non-healing wound.
Look after surgical wounds as advised and report any increasing redness, swelling, discharge or fever.

When to seek urgent help

See a doctor urgently, the same day, for increasing bone or deep pain with redness, warmth, swelling or fever; a wound that is not healing or is discharging – especially a foot wound if you have diabetes; or if you feel generally very unwell. Go to A&E or call 995 for signs of serious infection or sepsis, such as a high fever with shivering, confusion, a very fast heartbeat, or feeling very unwell. A GP can start the assessment and refer you, and an orthopaedic surgeon and infectious disease specialist manage established osteomyelitis. HealthHub has further guidance on diabetic foot care and wound warning signs. Do not delay, especially if you have diabetes.

Frequently asked questions

Is osteomyelitis an emergency?

It is serious and needs prompt medical care. Increasing bone pain with fever, redness or swelling, or a non-healing diabetic foot wound, should be seen the same day. Signs of sepsis – high fever with shivering, confusion or a very fast heartbeat – mean going to A&E or calling 995.

Can osteomyelitis be cured?

Acute bone infection caught and treated early often clears completely with antibiotics and, where needed, surgery. Chronic osteomyelitis is harder to clear and can need long-term care, but it can still be controlled by a specialist team.

Why does diabetes make osteomyelitis more likely?

Reduced sensation means foot injuries may go unnoticed, and poor circulation slows healing, so a small wound can deepen until it reaches bone. This is why daily foot checks and prompt care of any non-healing wound are so important.

Related bone, joint & muscle topics

Sources

NHS — Osteomyelitis: definition, symptoms, risk factors, antibiotic duration, surgery/debridement, urgent-care advice.
Cleveland Clinic — Osteomyelitis: causes, S. aureus as leading organism, acute vs chronic, complications.
Merck Manual (Professional) — Osteomyelitis: routes of infection, organisms, diagnosis and chronic disease detail.
SingHealth — limb salvage in complex diabetic foot wounds; HealthHub (TTSH) — diabetic foot care and non-healing-wound warning signs (SG context).

General information only. This guide is general information about a bone, joint or muscle condition and is not a diagnosis or personalised medical advice. See a doctor — a GP, sports physician or orthopaedic surgeon — for assessment, imaging and treatment. Go to A&E or call 995 for a suspected dislocation or broken bone, or for loss of bladder or bowel control, numbness around the groin, or severe or worsening weakness in the legs — these can be signs of serious nerve compression needing emergency care.