Serious Diabetic Foot Infections: Osteomyelitis

Diabetics are prone to several types of infections. One common and serious infection is osteomyelitis, which is an inflammation of bone. Such a problematic condition eventually causes death of the bone and surrounding tissue, leading to amputation, IF NOT CAUGHT AND TREATED EARLY.  At the first sign of an infection:  redness, pus, inflammation, heat and pain.  Osteomyelitis is often chronic in diabetics and must be constantly monitored.  It is commonly spread from a foot ulcer to the bone, if untreated. Signs of an infection of an ulcer include discharge, swelling, redness, tenderness or pain, and warmth to touch. If not treated swiftly, this can most definitely progress to osteomyelitis. Risk factors include deep wounds, neuropathy, Charcot’s foot [loss of the internal orientation of the bones, exuberant bone growth], poor blood circulation, poor control of sugar, and immune dysfunction.

The most common bacteria that cause osteomyelitis are Staph aureus. It is difficult to treat this type of bacteria because it is part of what is known as a biofilm. This is a community of bacteria protected by a matrix. The matrix is difficult to penetrate and so many antibiotics cannot damage the bacteria. The antibiotic, furthermore, must be able to also penetrate bone, which is the deepest tissue. The most common antibiotics given for osteomyelitis are penicillin’s and the closely related cephalosporins. If the patient has a penicillin allergy, Clindamycin or Vancomycin can be given. The antibiotic is usually administered with an IV in an outpatient setting. This is because the therapy must usually be done for a long time, and it also prevents gastrointestinal problems. Along with the antibiotic therapy, debridement or removal of the dead infected tissue must be done in order to break down the biofilm of the bacteria.  There is a relatively new antibiotic, linezolid (Zyvox®) which is given orally and very effective for the treatment of a particularly virulent type of Staph:  MRSA (methicillin resistant staph aureus). 

Especially when the infection becomes chronic, surgery may be necessary to treat osteomyelitis. Reconstruction of the limb is done in several different ways depending on the progression of the infection. Sometimes adjunctive therapy like revascularization of the limb or using hyperbaric oxygen therapy (HBO) is useful. However, the best chance of a positive outcome is when surgery, debridement, and antibiotics are used collectively.

 

At the first sign of a suspicious ulcer, drainage, a deep looking wound, consult your Podiatrist or PCP immediately.

Rao, Nalini, Ziran, Bruce, Lipsky, Benjamin. “Treating Osteomyelitis: Antibiotics and Surgery.” American Society of Plastic Surgeons Vol 127 Number 1S (2010): 177S-187S.