Osteomyelitis of the Foot

Osteomyelitis of the foot is an infection of the bone, which is usually bacterial in nature although can be caused by fungi or viruses. This condition involves inflammation of the bone or bone lining, although in severe cases the infection can spread to the bone marrow.
Osteomyelitis of the foot can occur in healthy individuals, although it is diabetic patients who are at most risk. Osteomyelitis of the foot is a fairly common and highly serious complication of diabetes.

Osteomyelitis is usually caused when infection spreads to the bone from the surrounding soft tissues, although it is possible that a blood borne infection can cause osteomyelitis to develop. Osteomyelitis of the foot can also develop following on from foot surgery if bacteria have entered in during the surgical process, or if infection takes hold in the wound post surgery. Osteomyelitis is most likely to occur after foot surgery when broken bones have been pinned in place. It is not unusual for antibiotics to be prescribed after surgery to limit the risk of bacterial infections such as osteomyelitis from developing.


Symptoms of Osteomyelitis of the Foot

The symptoms of osteomyelitis of the foot can mimic other disorders. However, in addition to bone and joint pain in the affected foot it is likely that some or all of the following symptoms will be experienced.

  • Fever
  • Chills
  • Excessive sweating
  • Swelling of the affected foot or ankle
  • Inflammation of the skin
  • General feeling of ill health

It is vital if osteomyelitis is suspected that you seek immediate medical attention. Signs of an infection rather than an injury to the bone are an elevated temperature, fever, chills and/or excessive sweating.
Osteomyelitis of the Foot and Diabetes

Osteomyelitis is commonly associated with diabetes mellitus; a metabolic disorder which affects the body’s ability to control blood sugar. The condition is due to reduced production of insulin or an insensitivity to this hormone. This disease can cause damage to the blood vessels and nervous system, and damage to the nerves in the feet (diabetic neuropathy) is a common complication from the disease. Due to a lack of feeling in the feet, cuts and abrasions may not be noticed and it is therefore far easier for an infection to take hold with diabetics. Since the circulation is also damaged by this disease, healing is much slower and infections can become serious very quickly. Any foot wound can potentially lead to a bone infection developing if it is not treated quickly.

Diagnosis of Osteomyelitis of the Foot

Osteomyelitis of the foot cannot be diagnosed with any certainty by a patient at home, and neither can it be treated without medical intervention. It is therefore important that a doctor is consulted promptly if osteomyelitis of the foot is suspected. Diagnosis of osteomyelitis is made using a number of clinical imaging tests such as an MRI scans, bone scans or taking an X-ray. Blood tests may also be required to determine whether there is an infection present, and may be performed initially before bone scans and more expensive imaging tests are arranged.

Treatment of Osteomyelitis

Treatment of osteomyelitis of the foot may be straightforward; however a course of oral antibiotics may not be sufficient to clear up the bone infection. With osteomyelitis it is common for antibiotics to be taken intravenously, and this treatment will almost certainly be required for more severe infections. When antibiotics are administered by IV they are able to work faster and will help to get the infection under control quickly. This is particularly important to prevent permanent damage being caused to the bone.

The course of antibiotics is usually longer than for soft tissue infections; a minimum course of 6 weeks is certainly to be expected. The best antibiotic treatment will depend on the causative agent. It may therefore be necessary to culture bacteria to determine the correct antibiotics to use, and combinations of antibiotics may be required. When there is an associated wound or ulceration of the foot it is vital that the wound is kept clean and pressure on is reduced to facilitate the healing process.
Depending on the severity of osteomyelitis of the foot it may be necessary for dead tissue to be removed – termed debridement. In some cases, such as with osteomyelitis of the toes, amputation of the affected digit may be the best choice to prevent the infection from spreading and to facilitate the healing process.

In the majority of cases osteomyelitis of the foot can be effectively treated and managed, although the chances of making a full recovery will depend on the early identification of the condition, its severity and whether the infection responds to antibiotics.


Sources:

Benjamin A. Lipsky – Osteomyelitis of the Foot in Diabetic Patients; Clin Infect Dis. 1997 Dec;25(6):1318-26
PK Henke et al – Osteomyelitis of the Foot and Toe in Adults Is a Surgical Disease – Ann Surg. 2005 June; 241(6): 885–894.