STIMULAN in trauma – surgeon’s views

I’m Dr. David Weiss. I’m an orthopaedic trauma surgeon in Charlottesville, Virginia, and I work at a level one trauma center, an academic trauma center, and primarily take care of trauma or sequelae of trauma. So acute injuries, chronic injuries, infections, malunions, non-unions, all kinds of anything to do with trauma, the world of trauma.

My name is Richard Yoon, I’m an orthopaedic trauma and adult reconstruction surgeon out of Jersey City, New Jersey.

Dr. Weiss: The body normally has this really robust immune system that protects you against infection because bacteria live all around us. The problem when you’re in a trauma, is that there’s a few different things that can happen. One, some people have an open fracture. So the bone or their tissue is exposed to that outside world, and that violates that protective barrier that we normally have. The other problem is that even if you didn’t have an open fracture, your systems have been exposed to trauma. Potentially you’ve had chest or head trauma, you’ve got this inflammatory response that occurs. There can be a big hematoma that occurs at a fracture site or an injury site. Now you have damaged tissue with less vascularity and a lot of potential for bacteria to get into your body, to have a place to take up residence and cause infection. We definitely know that trauma is a risk factor for infection, certainly open fractures or trauma that penetrates your skin barrier is a risk. But even just generally having trauma is an increased risk factor for infection.

Dr. Yoon: There are several reasons for infection to occur after trauma procedures. Obviously open fractures, ones that are grossly contaminated, especially if you’re in a freshwater or saltwater scenario or even in a by the side of the road scenario. Poor host factors, poorly controlled diabetics, chronic smokers, patients who are vasculopaths. These are all harbingers for infection down the line. And these are all things that we worry about when we take care of our trauma patients as well as our reconstruction patients.

Dr. Weiss: Infection can come in all different shapes and sizes. We have these very obvious signs that can occur. Some people will show up and they’ll have swelling, they’ll have redness, they’ll have drainage. But then sometimes there’s less obvious signs. Some people show up, they just have pain. They’ve got a fracture that hasn’t healed, which is what we’d call a non-union. They might have some loosening of their implants, something that suggests something is wrong.

I like to describe infections to patients like fires because I think it really helps them understand it. I talk to them about making a fire in their backyard, like if they’re having friends over to roast marshmallows or hot dogs. And I say, “you know, I bet you can build a really good fire.” And they say, “yeah, I can.” And I say, and probably everybody says, “oh, yeah, that’s a nice fire.” “It’s nice and warm and people are warming themselves, it’s a cold night.” And so that’s like a hot infection. That’s a very obvious infection, like a really big fire. But then at the end of the night, the fire burns down. And sometimes you just have some embers. And I say, “is the fire out?” “Do you know if it’s out or not?” And infections can be like that, too. You can have some very smoldering infections, very low-level infections that are hard to pick up sometimes. Just like that fire scenario, if you blow on those embers, sometimes they’ll flare up. Sometimes people have a low-level infection that will pop up or cause some problems. Sometimes they are hard to diagnose because they’re very subtle, but if you’re suspicious for them, then you can find them.

Dr.  Yoon: Signs and symptoms of a present infection, a lot of them are subjective. If there’s a draining wound, it’s infected, I don’t have to prove it otherwise. Obviously red, hot to the touch. More specific parameters are laboratory parameters. We look at ESR, CRP, CBC, and then other times we get advanced imaging. Bone scans can be helpful sometimes as well as MRIs and CT with and without contrast.

Dr. Yoon: My typical treatment pathway for infection really starts at the time of injury. You have to make sure that the debridement is appropriate. For large, grossly contaminated wounds that we know are coming back, I like to load calcium sulfate beads with antibiotic. Certainly, when we’re doing arthroplasty, there’s a lot of host factors you want to optimize prior to the surgery. But those who come in already infected, it’s important to get all the metal out and place some kind of stable construct where there’s a knee to the hip so that you can have neovascularity. And of course, deep eluting spacers or calcium sulfate loaded antibiotics to help control the deep space. This is supplemented with IV antibiotics for six weeks and then some trending labs to make sure everything’s normalizing over that time as well.

Dr. Weiss: I think if we’re strongly suspecting infection or it’s clear that there is infection, that very hot fire, the first thing is to identify the organism. I think if you can identify what the organism is, that will then help target your treatment. In the world of trauma, we’re almost always dealing with infections that are related to fractures. And so the next question is, is the fracture healed, because that really changes how we’re going to move forward with our treatment plan.

If the fracture is healed, I don’t have to worry about getting the fracture healed. We just have to worry about getting rid of the infection. And so our treatment tends towards typically getting rid of implants that might be potentiating infections and then treating the infection. If the fracture hasn’t healed, we’ve got to get the fracture to heal in association with treating the infection. We have to make that determination and then we move forward with treatment, which involves a combination of getting rid of infected tissue, so debridement, decision making on implants, and then sterilizing the tissue by delivering antibiotics. And we do that with a combination of local antibiotics and systemic antibiotics, targeted against the organism that we’ve identified.

Dr. Yoon: In my practice we have a highly complex referral base, a lot of infections, a lot of redo surgeries, both on the trauma as well as on the arthroplasty side. If a patient is high risk, morbidly obese, diabetic, they should be well controlled, a smoker, multiple revised patient, especially in my arthroplasty setting, I’ll load antibiotic into the calcium sulfate and I’ll inject it up and down the femoral canals. Typically, if there’s an infected non-union or even infected hardware, for example in the tibia, I’ll inject antibiotic loaded STIMULAN down the canal prior to nail insertion, so you have a pseudo-coated nail able to lock. There’s a lot of options that we can get creative with, but my preference is to put the antibiotic loaded sulfate as deep as possible, preferentially intramedullary, so you don’t have any of the drainage issues or anything like that.

Dr. Weiss: Cases where there are significant voids in the bone are great cases for products like STIMULAN. The issue is you need to fill in this space or the body’s going to fill it in with something, and that something could be a source of a reservoir for infection to continue. People who have bone loss, we worry about. Sometimes if you’ve taken implants out, intramedullary nails are a good example, we have this big void in the center of the bone that we want to fill up with a product like STIMULAN to allow us to get really good sustained antibiotic coverage in that area. And so, those are the areas that I typically think towards STIMULAN.

Dr. Weiss: The first question is, have we identified the organism? Because if we’ve identified that it’s a gram-positive organism, then we typically like to use vancomycin. It’s a great antibiotic to use with STIMULAN. It really sets up nicely, it has great elution potential, it has great elution factors, and we can get really high local concentrations. If we know it’s a gram-negative organism, I’ll typically use tobramycin. That’s my go-to. It comes in a powder form and mixes in nicely into the STIMULAN product, and again, has a good elution profile, very good effectiveness against gram-negative, but also even some gram-positive organisms because the high local concentrations of tobramycin can be very effective. So a lot of times it depends on what organism we’ve either identified or we think is the culprit, we’ll choose an antibiotic for that. You can also use gentamicin that comes in a liquid form. Our hospital tends to have tobramycin available, which is just very easy to use in a powder form.

Dr. Yoon: Which antibiotic is important. Obviously, if it’s a gross contaminated situation, you would typically like tobramycin, something that has a little bit more gram-negative coverage. If you’re worried about skin flora, vanco is probably the easiest and cheapest thing to load it with, but those are my go-to options.

Dr. Yoon: To show me that STIMULAN is working, actually on follow-up x-rays you can see the actual sulfate dissolve. I use a lot of fluoroscopy intra-op so we know that it’s down the canals where we want it to be. And then of course as you get in the laboratory values and following up and everything’s normalizing, clearing the infection is a win and that’s what you want to see happen, especially after the antibiotics are off.

Dr. Weiss: This is always a question people ask, how do you know when an infection is gone? And typically I’ll look at if we have a bone void, is the void being filled in? Because STIMULAN will be reabsorbed, but it oftentimes can lead to filling in of that void with bone tissue. Do patients feel better? Is their pain better? They’re less swelled and less painful, able to get around better? Are their inflammatory markers going down? It’s just a combination of things. It’s rarely just one thing that you see, but a combination of things.

Dr. Yoon: The main tip I would have for trauma surgeons new to using STIMULAN is that it’s definitely a cost-effective way to use and apply antibiotic loaded beads in a deep-sea scenario, especially if you’re coming back from multiple debridements. My tip would be to start making it at the beginning of the case and have your scrub tech or your resident put it in the pan to get the beads going early. That way, when you’re ready to put it in, they’re ready to go. The other comment I would say, is that if you’re not going to use it in a multiple debridement scenario, say a high-risk patient where you’re injecting it down a canal or that kind of scenario, I think that adjunct has saved me a couple times. And it’s certainly something that I think when you put it deep within the bone, you’re getting all the benefits without the drainage.

Dr. Weiss: I think there’s a few things that are really important. The mixing profiles, particularly with using different antibiotics, are a little bit different, and so making sure that you understand and your team understands just how the mixing goes and how to apply the product. It’s very similar to baking. You have to be precise with your ingredients, and if you’re not precise, you won’t end up with a good baked product. Your cookies will be flat or your muffins won’t rise or something like that. With whichever antibiotic that you’re using for it, make sure that you have the appropriate amounts of moist material and dry materials. That’s probably the biggest tip.

Dr. Weiss: I think that probably the biggest lesson I’ve learned over the years of using STIMULAN is that it is important to have a good soft tissue envelope. You have to have a good layer of closure over the STIMULAN. Much better than any of the previous products on the market, there’s much less inflammatory response but there still can be some drainage from a wound, there still can be some discharge of the STIMULAN product. And so you have to understand that if you don’t have a good soft tissue coverage, that may happen.

And that doesn’t necessarily mean there’s a problem. In fact, oftentimes there’s not, but the patients will be concerned, your nursing staff may be concerned, you may get a lot of phone calls. And so recognize that if you can get a good soft tissue layer closed over the STIMULAN, then that won’t happen. And if you don’t, that there may be some drainage for a few days that is usually very sterile and not something to worry about, but oftentimes engenders some phone calls and some reactions.

Dr. Yoon: The number one mistake is that they put it too close to the surface. They put it in the subcutaneous tissue, they don’t put it deep to the fascia, and that’s where you’re going to have this serous drainage that is not fun for you or the patient. So I think that’s the number one mistake folks do when they start using it. You just keep it deep and you’ll get out of trouble.

Dr. Yoon: I was an early adopter. I started using it even as a resident, as a fellow. Being at a tertiary referral center at both places, we got a lot of complex infection scenarios that were referred over. Once we managed that and I came into practice, it’s been a mainstay of my practice in terms of complex primary joints, obviously the infected joints, revision joints, and then again highly contaminated, high-risk patients in the trauma setting. It’s certainly a mainstay adjunct in my clinical practice.

Dr. Weiss: Yeah, that’s a good question. I think I’ve been using STIMULAN for about 10 years. It’s something that has been useful for me in these very difficult-to-treat fracture-related infections. It’s been a good product for getting antibiotics to the scene and delivering them over a sustained period of time, which I think is really helpful. I’ve become a real believer in local antibiotics because systemic antibiotics, while effective, just don’t have the same power as delivering something directly to the wound bed. You can do it at much higher concentrations, at much lower toxicity than you can with systemic antibiotics. And it’s allowed me to be much more aggressive in treating infections and getting them eradicated at an earlier phase. I think it leads to fewer operations and more success. So it’s really been an effective tool for me.

Dr. Weiss: I think it gives me that local delivery of antibiotics in combination with filling bone voids. When it’s used effectively, it can essentially increase your cure rates, decrease your re-operation rates, which is really what we want in the end for patients – fewer operations and more success.

Dr. Yoon: No one likes an infection. I always tell my patients that no, just like you, I don’t want a complication just as much as you don’t want a complication. Infection is the thing that we want to avoid the most because especially when there’s metal involved, it’s not like you can go to the doctor and get a week of antibiotics and you’re fine. It usually means more surgery and when you do this long enough, you want to make sure that you’re going to be one and done, and when you can, save the complications and minimize them as much as possible, and avoid an additional surgery.

Dr. Yoon: STIMULAN as an adjunct benefits my patients because it keeps them out of the ER and keeps them out of the OR. Obviously host factors are things you have to modify. If you have a poorly controlled diabetic, make sure the sugars are good. Smoking cessation, counseling, all these little things are important as well. However, what you can control as a surgeon is important, and STIMULAN is one of those that helps us minimize infection.

Dr. Weiss: I think that we’ve been able to see improved success rates when using it and treating fracture-related infections. These infections can be very difficult to treat. They can be very problematic. They can stick around for a long period of time and lead to multiple operations, multiple surgeries. And we’ve been able to improve those numbers with STIMULAN. It doesn’t eliminate it, it doesn’t solve every problem, but it certainly gives us a very powerful tool to treat these infections.