Editor's Note: In this interview, Ronald Sherman, DPM, MBA, and Christopher Abularrage, MD, address the steps they take to treat infected diabetic foot wounds of varying degrees, including those with osteomyelitis.

Transcript

1. When treating an infected foot wound, what first steps do you take to address it?

Dr. Sherman: There has to be a standard of care. You have to have your scout x-rays, you have to have your non-invasives on your first visit. You have to do your culture, right? And what did we find about giving empiric antibiotics to these patients? So for chronic wounds, we wouldn't necessarily give empiric antibiotics because chances are they've had so many antibiotics in the past, you're not going to be that effective. But if there's a cellulitis and if there is a spreading of the infection, I think that you can give empiric antibiotics. And we've found that to be around 50% effective. Right? 50% good choice. You know what I mean? So I think to begin with, that would be the easiest thing to do. And if the wound probes the bone or if the wound has a remote chance of healing, then the patient must come into the hospital for debridement. There's no question about that. I think that the development of osteomyelitis occurs because of a persistent, chronic wound. And when wounds become persistent and chronic in a diabetic, we know how the manifestations of diabetes affects that. We know how it affects the extracellular matrix.

We know how it affects the cells within the wound. We know that macrophages don't work well anymore. We know that the migration and the chemotaxis of these cells don't work well. We know that actually the construction of collagen from the fibroblasts doesn't work well at all, that you get the reactive oxygenation species. A whole new environment develops with these chronic wounds. So I think that if we take this infected wound, treat it aggressively, that's the way you have to treat these type of diabetic infections. Dr. Abularrage?

Dr. Abularrage: The only thing that I would add is, especially in not so much the acute wounds, but in the chronic wounds, we actually wait for the sensitivities to come back from a culture. Initially, we were giving people empiric antibiotics on what we thought would be appropriate, on what the guidelines would suggest were appropriate, and we're finding that many of the cultures were coming back where they were resistant to the initial antibiotic. And so basically what we were doing is we were giving 3 days of an antibiotic for no reason whatsoever. So I understand if there's a massive erythema or there's some other issue where you really feel strongly that they need an empiric antibiotic, but for most of these diabetic foot wounds, doing a culture of tissue and then waiting for the sensitivities to come back will really limit the use of antibiotics that aren't therapeutic.

Dr. Sherman: And I want to talk about culturing just for a little bit. We may do culturing a little bit different here. So one of the things that we found early on in our practice was that we were culturing a lot and we were getting a lot of organisms. So what we decided to do is to really review the culturing process of wounds. So what we do is that we first cleanse a wound with Betadine solution to reduce as much contamination as possible, and then we take our swab and we put pressure on the swab to exert fluids that will then go into the swab themselves as opposed to a very superficial swab. So we first cleanse the wound with Betadine solution, then we take a swab and we either use the Z technique or we put pressure on the swab to emit the fluids beneath the wound so it goes into the swab.

2. Considering the multidisciplinary approach, what would it look like for the treatment of osteomyelitis?

Dr. Sherman: Oftentimes when we see patients together, the very first thing we do is look at the wound. We pull it out, we pull out our wooden applicator stick and we probe it. Dr. Abularrage comes out of the room and say, "Ron, probe's to bone. Let's get him in the hospital." So we know that probing to bone is about 90% sure that it has osteomyelitis. So we're very aggressive with that, as you know. Again, we get our preliminary x-rays. We do get MRIs oftentimes if they come for second opinions, to see what the extent of the osteomyelitis is and if we can actually salvage the foot. So we're very aggressive with osteomyelitis. We're aggressive in our debridements. Oftentimes we have staged procedures.

Dr. Abularrage calls it the Sherman procedure, where we oftentimes stage the patient for an initial debridement and then follow up debridement. We don't do more than maybe one and a half debridements on our patients on average, but we're pretty thorough in that. And then once we get our margin, then we can actually reconstruct directly on the bone and utilize the MSCs within the bone marrow to help with the bone healing. And Dr. Abularrage also stated that we're very liberal with parenteral antibiotics. So if a foot has osteomyelitis from the metatarsals proximal, they're going to get probably 4 to 6 weeks for sure. Okay? And that's what we found is another game changer with our limb preservation rates.

Dr. Abularrage: I would also point out the chronicity of the wounds that we see are probably significantly more chronic than the average podiatrist, which leads to this aggressive treatment of osteomyelitis. All of that being said, when I started on faculty here years ago, I was told that heel osteomyelitis or calcaneal osteomyelitis was a death sentence for the leg. And the reality is, is that it's not. We've developed paradigms in regards to that, MRIs to try to figure out exactly how deep that heel is infected, and if you're going to resect all of that osteomyelitis, what function they'll have at the end of it. But that's allowed us to truly change limb preservation here at Johns Hopkins. It's reliance upon more surgical therapy with IV therapy being a secondary postoperatively. When I teach our fellows about osteomyelitis, I tell them it's like cancer. You go and you take out someone's pancreas, they still have disease somewhere. You may not know where it is, but they're going to get adjuvant chemoradiation. I see antibiotic therapy to be sort of the same thing. We can cut out as much as we think is appropriate to get a "clean margin," but there's going to be some residual infection in there. And that extra 4 to 6 weeks of IV antibiotic therapy are key.

About the Speakers

Ronald Sherman, DPM, MBA, is the podiatric surgeon in the Division of Vascular Surgery and Endovascular Therapy at Johns Hopkins Hospital. He graduated from the New York College of Podiatric Medicine and completed his surgical training at Lutheran Hospital in Baltimore. He has served as a Residency Director in podiatric surgery for over a decade at both University of Maryland Medical System and Mercy Medical Center, having graduated more than thirty podiatric physicians. With over 41 years of experience, he has developed an expertise in the care of the diabetic foot wound and the lower extremity. Dr. Sherman has been contributing to the Johns Hopkins Multidisciplinary Diabetic Foot and Wound Clinic as a principle clinician since 2012 focusing on healing unresponsive foot ulcerations and reconstruction of diabetic wounds.

Christopher Abularrage, MD, specializes in vascular and endovascular surgery, with a specific interest in minimally invasive techniques for lower extremity peripheral arterial disease and aneurysm repair. His clinical interests include limb preservation, Diabetic peripheral arterial disease and limb salvage, aortic aneurysms, endovascular aneurysm repair, visceral stents and bypass, and carotid stents and carotid endarterectomy. He is an active researcher within the department and has published widely on outcomes research using large, national databases. Recently, Dr. Abularrage and his team have published their outcomes of patients treated in the Multidisciplinary Diabetic Foot & Wound Clinic, showing significantly lower amputation rates compared to national benchmarks. Dr. Abularrage is a distinguished fellow to the Society of the American Board of Surgery, and recipient of the Zehner Award and the R. Clement Darling, Jr. Award. He is nationally renowned for his work in Diabetic peripheral arterial disease and limb preservation.