Tuesday, June 28, 2011

How Did You Get Osteomyelitis?

Last blog entry gave a very brief overview of some of the more common imaging studies that Podiatrist’s tend to order to help them confirm their diagnosis. It reading that blog, your interest may have been peeked when the idea of bone infection was introduced, as it was discussed under several of the imaging modalities since bone infection can be captured in various ways. This week, I hope to indulge your newfound interest and provide some insight into the topic of bone infection. This topic is not an easy one to broach, as there are many questions when dealing with bone infections that must be answered. The why and the how of bone infection in a patient can sometimes be very clear-cut and in other patients, can be quite a mystery. The key, however, in treating bone infections is prompt diagnosis!

Let’s break it down a bit:

What is a bone infection? Bone infection, more commonly referred to as Osteomyelitis (Osteo = bone; meylo = marrow; itis = inflammation) is exactly as it sounds. Infection, much the same as would present in the skin, invades into bone allowing bacteria to thrive and wreak havoc. The severity of the bone infection depends on a number of variables, some of the more important of which are: how much bone is infected, the condition of the surrounding soft tissue structures, if the infection has traveled to other areas of the foot and leg, and the health status of the infected patient.

Who gets bone infections? Patients who are at a higher risk include those who have suffered an open fracture (one where the skin was opened upon fracture of bone) and those who present with chronic (long standing) open and infected foot ulcerations/wounds. However, anyone can suffer from osteomyelitis. In reactivated forms of osteomyelitis, bone infection occurred years ago but the infection suppressed by the body; secondary to trauma to the previously infected area, reactivation can occur.

When should you become suspicious of a bone infection? Those patients who should have the highest index of suspicion for a bone infection are those patients who are at a higher risk (i.e. open fracture patients and those with long standing infected wounds). If you are being treated for a long-standing non-healing wound, additional imaging studies may be recommended to rule osteomyelitis in or out. In a healthy patient signs of infection include redness, swelling and heat in the suspicious area, but in those patients with chronic wounds and a compromised immune system, such as Diabetics, those same symptoms may never present themselves.

Why is early recognition key? Early recognition is key so that initiation of treatment is prompt. The earlier bone infections are diagnosed, the better the treatment outcomes. The worry is that bone infections will continue to spread to adjacent bones and additional soft tissue structures causing larger infections that are more difficult to treat with antibiotics alone.

Where is the most common location in the foot and ankle? The most common location of osteomyelitis in the foot is underneath the metatarsal heads. The metatarsal are the long bones of the foot that connect to the toes. The location of the metatarsal heads is in the approximate area of the fat-pad of the forefoot. This area is most commonly affected because the metatarsal heads are under high pressures throughout gait.

How do we treat bone infections? Treating bone infections is very tricky and among other things, Podiatrists must carefully consider each patient before deciding on a treatment regimen that is best for that particular patient. Almost all patients will be placed on antibiotics, but depending on the severity of the infection depends on if those antibiotics will be administered in pill form or via an IV (intravenous) infusion. If you have a bone infection, expect to be on antibiotics for 4 weeks at the very least, but typically longer courses are required. If a bone infection has become so severe that antibiotics are only effective in keeping the infection at bay but will not eliminate the bacteria from the body all-together, surgical intervention is usually necessary. Surgery entails finding the source of the infection and any collections of infectious fluid and draining them, in addition to washing-out all the surrounding soft tissues and removing any bone that is dead/dying.

Osteomyelitis can be a scary and tricky diagnosis to face, but conversations with your Podiatrist (should you be diagnosed) can be very informative and will lead you towards the most appropriate treatment path with the greatest outcome for healing!