What is osteomyelitis of the foot

However, the common limitation is the low specificity in the discrimination between soft tissues and bone infection[ 34 ]. The specificity of leucocyte scan is better than triple-phase bone scan even if the spatial resolution can be a limiting factor.

However, labeled leukocyte imaging are more useful than bone scan for diagnosis, evaluation of bone affected and follow-up during medical treatment[ 35 , 36 ]. Leucocyte scan images showing area of increased uptake strongly suggestive of osteomyelitis in left mid and hindfoot.

Positron emission tomography images demonstrating diffuse increased of 18Ffluorodeoxy-D-glucose uptake of the right foot suggestive of severe osteomyelitis. The gadolinium uptake allows to distinguish between soft tissues and bone better than CT and scintigraphic methods[ 43 , 44 ].

The typical changes in the bone marrow predictive for osteomyelitis are low signal intensity on T1-weighted sequences and high signal intensity on T2-weighted sequences. These findings may be already evident 3 d after the onset of infection. The major limit is the reduced resolution in the evaluation of cortical bone that does not allow to highlight few cases of infection such as osteitis or to distinguish other causes of bone injury[ 45 , 46 ].

Osteomyelitis of second toe distal phalanx revealed by magnetic resonance imaging. The arrows and the arrowhead show the bone involvement of distal phalanx second toe. Severe osteomyelitis involving midfoot, hindfoot and ankle detected by magnetic resonance imaging. Severe osteomyelitis of forefoot, mid and hindfoot by positron emission tomography-computed tomography. The gold standard for the diagnosis of osteomyelitis is the bone biopsy which provides histological and microbiological findings[ 21 , 22 ].

Histological criteria are: Bone erosion, marrow edema, fibrosis, necrosis, presence of inflammatory cells both acute and chronic , seizure. Furthermore, the bone biopsy allows to identify precisely the bacteria involved in the infectious process and to evaluate the susceptibility to antibiotic therapy.

The bone can be removed by a percutaneous approach through a not infected skin or during the open surgical procedures. Therefore, superficial swab should not be used in case of DFO. Bone biopsy is the most accurate test preferably after 10 d of antibiotic suspension even if in several cases it is not technically feasible.

However, a recent study showed that the pathogens isolated from culture of deep tissues removed from the area closest to the bone are very similar to those obtained from bone biopsy The treatment of DFO remains a hot topic in the field of diabetic foot. Over the years the most debated theories have been surgical or antibiotic therapy as first approach. Nowadays the treatment of osteomyelitis is not completely standardized and evaluated case by case. Therefore, the guidelines broadly recommend the specific conditions for surgical or medical approach combined with conservative surgery.

Conservative surgery means usually a procedure in which only the infected bone and the non-viable soft tissues are removed without any amputation[ 16 ]. Tan et al[ 49 ] have shown that an aggressive surgical approach with minor amputation reduces the risk of major amputation above the ankle and reduce the length of hospitalization and associated costs. The Authors report that forefoot amputation reduces the risk of major amputation in comparison to medical therapy performed for 3 d[ 49 ].

However, antibiotic therapy was performed only for 3 d and it is well known that DFO can require long antibiotic therapy. Although an aggressive surgical approach could be mandatory under some circumstances, retrospective studies have shown that conservative treatment associated with prolonged antibiotic therapy is effective to promote wound healing and reduce the risk of major amputation and of ulcers recurrence[ 16 , 50 , 51 ].

Antibiotic therapy is widely used in association to surgical approach, both for minimal or extended procedures; however, several studies have reported many cases of DFO treated only by antibiotic therapy without surgery. Some Authors have reduced the role of surgery to treat bone infection, mainly in case of chronic osteomyelitis[ 52 - 54 ]. A recent prospective randomized clinical study has compared conservative surgery removal of bone without amputation of any part of the foot and antibiotic therapy alone.

Severe infection, patients with PAD and severe co-morbidity were excluded. Osteomyelitis were located in the forefoot.

The surgical group received empirical antibiotic therapy after the procedure. The group treated by antibiotics alone received for 90 d a targeted treatment according to the microbiological culture of deep soft tissues localized near the bone. The patient were followed for 12 mo after wound healing The rate of wound healing and healing time for respectively surgical and medical groups was similar Only No patient received major amputation[ 55 ].

Also the optimal duration of antibiotic therapy is not completely defined. The Infectious Disease Society of America IDSA considers wk adequate when the infected bone is not completely removed by surgery while at least 3 mo in case of antibiotic therapy alone[ 21 ]. However, the recent report of International Working Group of Diabetic Foot IWGDF suggested 6 wk of antibiotic therapy if the infected bone was not removed by surgery and no more than a week if infected bone was resected[ 22 ].

Lately, the aim is to reduce the duration of antibiotic therapy. In fact, prolonged use of antibiotics increases the risk of bacterial resistance, side effects and costs. A prospective randomized study compared two groups of not ischemic patients with DFUs on the forefoot complicated by osteomyelitis treated with antibiotic therapy respectively for 6 or 12 wk.

At the beginning antibiotic therapy was empirical and then driven by microbiological results. Sixty-six percent of patients resolved the osteomyelitis and there was not a significant difference between the two groups. Furthermore, the group treated for 12 wk showed more side effects than the group treated for six weeks[ 56 ]. A significant aspect is to define the resolution of bone infection. Nowadays, there are no tests correlated to long-term resolution of osteomyelitis. The IWGDF suggest that a decrease of serum inflammatory markers, especially ESR, associated with the resolution of soft tissue infection, healing and positive evolution of radiological signs can be used to stop antibiotic therapy.

Chronic osteomyelitis is associated with a high percentage of recurrence despite a long antibiotic therapy. Recurrence might be related to the incomplete resection of infected bone or to resistant microorganisms persistently remaining in their biofilm[ 57 ]. The recurrence of DFO has to be considered in case of ulcer reappearance within 12 mo after the first healing. Furthermore, recurrent foot ulceration can promote the reappearance of bone infection.

Adequate prevention is mandatory. Surgical and conservative approach shows advantages in some conditions and disadvantages in other. Several factors can influence the outcome. Among the advantages of surgical therapy there is the complete removal of the infected bone and the reduced duration of antibiotic therapy. On the other side an aggressive approach can lead to an extended tissue loss and it should be done only in patients with an adequate blood perfusion.

In children, these procedures are most often done in the operating room under general anesthesia. The goal for treatment of osteomyelitis is to cure the infection and minimize any long-term complications.

Treatment may include:. Administration of intravenous IV antibiotics , which may require hospitalization or may be given on an outpatient schedule. Intravenous or oral antibiotic treatment for osteomyelitis may be very extensive, lasting for many weeks. It is important for the patient to continue to take antibiotics for as long as recommended by the treatment team, even after symptoms of the infection have resolved.

In some cases, surgical intervention may be necessary to drain infectious fluid, or to remove damaged tissue and bone. Osteomyelitis requires long-term care to prevent further complications, including care to prevent the following:.

Health Home Conditions and Diseases. What is osteomyelitis? The source of the blood infection is usually Staphylococcus aureus , although it may be caused by a different type of bacteria or fungal organism Osteomyelitis can also occur from a nearby infection due to a traumatic injury, frequent medication injections, a surgical procedure or use of a prosthetic device.

What are the symptoms of osteomyelitis? A course of antibiotics or antifungal medicine is normally effective. For adults, this is usually a 4- to 6-week course of intravenous, or sometimes oral, antibiotics or antifungals.

Some patients need treatment in hospital, while others may receive injections as an outpatient, or at home if they can inject themselves. Possible side effects from antibiotics include diarrhea , vomiting, and nausea.

Sometimes there may be an allergic reaction. If the infection is caused by MRSA or some other drug-resistant bacteria, the patient may need a longer course of treatment and a combination of different medications. In some cases, hyperbaric oxygen therapy HBOT may be recommended. In sub-acute osteomyelitis, infection develops within 1—2 months of an injury, initial infection, or the start of an underlying disease.

If there is no bone damage, treatment is similar to that used in acute osteomyelitis, but If there is bone damage, treatment will be similar to that used in chronic osteomyelitis. In chronic osteomyelitis, infection starts at least 2 months after an injury, initial infection, or the start of an underlying disease. If the patient cannot tolerate surgery, for example, because of illness, the doctor may use antibiotics for longer, possibly years, to suppress the infection.

If the infection continues regardless, it may be necessary to amputate all or part of the infected limb. Other symptoms may include swelling of the ankles, feet, and legs, and changes in walking pattern, for example, a limp.

The symptoms of chronic osteomyelitis are not always not obvious, or they could resemble the symptoms of an injury. In children, osteomyelitis tends to be acute, and it usually appears within 2 weeks of a pre-existing blood infection. This is known as hematogenous osteomyelitis, and it is normally due to methicillin-resistant Staphylococcus aureus S. Diagnosis can be difficult, but it is important to get a diagnosis as soon as possible, because delaying diagnosis can lead to growth disturbances or deformity.

It can be fatal. In adults, sub-acute or chronic osteomyelitis are more common, especially after an injury or trauma, such as a fractured bone. If the infection is in a long bone such as an arm or leg , you may be fitted with a splint so you do not move it as often. If the infection has damaged the bone, you'll need surgery known as debridement to remove the damaged part. Sometimes more than one operation is needed to treat the infection.

Muscle and skin from another part of the body might be used to repair the area near the affected bone. It's very important to look after your feet if you have diabetes. If you have poorly controlled diabetes, you can lose sensation in your feet and not notice small cuts, which could develop into an infection that spreads to the bone.