Bone and Joint Infections

Podcast Transcript

Raed Dweik, MD:

Hello, and welcome to the Respiratory Inspirations podcast. I'm Raed Dweik, chairman of the Respiratory Institute at the Cleveland Clinic. This podcast series of short, digestible episodes is intended for patients and families, and covers topics related to respiratory health and disease. My colleagues and I will be interviewing experts about timely and timeless topics in the areas of pulmonary, critical illness, sleep, infectious disease, and related disciplines. We will share with you information that will help you take better care of yourself and your loved ones. I hope you enjoy today's episode.

Steven Gordon, MD:

Well, thank you very much, everyone, for joining us today for the podcast and it's a pleasure for me to have a colleague and a friend and a guest here, Dr. Maja Babic, MD, who's gonna talk to us about bone and joint infections from the ID perspective, but also kind of her approach. And I think this is for me, it's a very interesting topic. Hopefully, we'll try and make it interesting for you as well. So, let's start. Maja, can you just give us a little bit about your background in terms of how you got to the clinic and your interest in infectious diseases and bone and joint infections?

Maja Babic, MD:

Sure, I married in the clinic. I did my infectious disease fellowship across the street at University Hospitals, and the rest of my family is at the Cleveland Clinic. And once I was done, I jumped ship to join my husband at the clinic. That's how we got here.

Steven Gordon, MD:

Wow. Well, we'll get back to your husband, Klaus, because the through line, obviously, when we're talking about bone and joint infection service, it just isn't an infectious disease. So, I wonder if you can explain your approach in this team that you joined in that what makes a successful team and why you need a team for a bone and joint infections.

Maja Babic, MD:

So, when people go into infectious disease, very few of us actually have a tunnel vision of what we're going to do. It's a big field. And it's an exciting field. And you sort of overtime, depending on your interests, and connections get thrown into areas that you either like or don't like, and if you do like it, and if you manage to establish good connections with other people who are in that field, then you grab it and run. So, that's I think how I ended up with bone and joint infections. When I interviewed with you, I still wasn't differentiated, I want to say, but I think you sort of steered me a little more, since you realized the connection that was there in between, you know, infectious disease, and the musculoskeletal radiology department and orthopedics. So, I was lucky enough that the Cleveland Clinic does have subspecialties, actually, very few hospitals across the country have the sub-specialized infectious disease department within an infectious disease department.

But I think as medicine advances, and as the population gets older, I think that's where we're headed, we're getting more and more sub-specialized. And since you want to be taken care of by people that are specialized in that particular area, then I think that that's where it's headed. I get surprised by patients who eventually show up at our door, and, you know, with a bone and joint issue in infectious disease, and after we see them and tell them, okay, this is what you've got. They look at it, and they say, "How come it took you just five minutes to realize what I have when I was just bouncing around everywhere?" And I always tell them not to give us too much credit because we are in a box. This is what we do. And if we didn't know what it was, we'd really be bad.

Steven Gordon, MD:

So, I think you're being modest, but I would agree that working with people that share the same disease process or line process, so for instance, you'd spend a lot of the time as you said, either communicating with your imaging people or with orthopedic surgeons, obviously microbiology comes in there as well as surgical pathology. But I'm just curious, you know, there's over 200 bones in our body when we think about bone and joint infections, but obviously, although all of them probably can get infected, can you give us an idea of the distribution of bone and joint infections that we see here in the hospital in the outpatient, and then maybe go on and talk about, you know, osteogenesis or prosthetic devices and things of this nature?

Maja Babic, MD:

So, our population is getting older, and therefore, our musculoskeletal system is being worn down, worn out. And the areas that young kids never have an issue with become a point of least resistance for bacterial infections in older patients. So, I want to say have a few categories, you know, diabetes is rampant, so there's a lot of what we do are infections related to diabetes, of what we call diabetic foot infection, because this is a vulnerable foot, it is not equipped with defense mechanisms, you know, it doesn't have nerves that function very well to alert you that something is going on and the blood supply is compromised. So that's a bucket of very vulnerable feet. And I want to say that at least 30 percent of our infections deal with diabetic feet.

The other group is septic joints. And those can affect any major large joint in the body, knees, hips, shoulders, and it is surprising how actually little insight patients have into what a septic joint really is, because it is not very common. As common things are common, everybody always thinks that maybe this is an inflammatory reaction, or I pulled a muscle or, so patients very often sit it out at home for a few days. And I am going to use this opportunity to scare everybody that a septic joint is an emergency. And the red flags are, if you've had any kind of remote, skin tear, skin infection, anything that can be an entry point or a bad tooth. And if after a few days, your joints swell up the knee, or the elbow or the shoulder. And you notice that this is a throbbing pain that wakes you up at night and that is progressing, you should get it looked at.

I always tell the patients they should teach this in high school, throbbing pain in a joint that keeps you up at night, cannot be just treated with ibuprofen, it needs to be evaluated, especially if there is a preceding injury on the skin, that you didn't even pay attention to that, you know, a cut that oozed maybe a couple of days. Or if there's anything going on in the mouth, you know, tooth pain, these bacteria will use this opportunity to go float around in the bloodstream and then latch on joint surfaces that in the older population are not smooth anymore. Kids will not get this type of bacteremia, septic joints because their cartilage is nice and smooth. It is not sticky for bacteria.

Steven Gordon, MD:

Well, I think that's very good advice in terms of this, not to put people in a catastrophic bias but the other bucket you see, and I know that you've written a lot about this is infections of the spine. And you know, back pain is so prevalent, but I wonder if you can give us just a little bit of high level in terms of similarly, when clinicians or patients should be worried about back pain with a potential that you might be having an infection in their bones, in our lumbar or thoracic spine.

Maja Babic, MD:

So, the spine and older people are also vulnerable. There are tiny little joints in the spine, that are called facet joints or the disc spaces that are sort of equivalent to a joint because they have cartilage and that gets worn out too. So, it's the same rule. If you have back pain that throbs at night and just progresses to the point that you cannot sleep and you've been seen in the emergency department multiple times, then you, and you know the emergency department docs, they see back pain every day and it's usually musculoskeletal, but actually just to take this as an opportunity to tell the emergency department documents one lab that is the most helpful differentiating back pain that is musculoskeletal from serious back pain in the emergency department is the C-reactive protein.

So, I want to say that everybody who walks in, if they come in the second time, because with spine infections, they're not really easy to diagnose. We have a registry at the Cleveland Clinic and on average, people with infections in the spine have been seen in the emergency department at least three times. I recommend that, you know, if they show up the second time, instead of just a regular x-ray, they get a C-reactive protein. That is your best friend in making the distinction in between this is just musculoskeletal pain, it's not serious. And then there are these three categories, which are serious, and those are infection of the spine, underlying malignancy or a fracture, trauma, CRP and all these three cases will be elevated.

Steven Gordon, MD:

Well, okay, that's very useful information, again, not to scare people. With all your experience, is a physical exam still important?

Maja Babic, MD:

If you ask targeted questions, the patients will answer correctly, but unfortunately, I think we ask too many in order to fill out this H and P form that we're supposed to, but targeted my main question to the patient is. Where does it hurt? When did it start? Is it in the middle? Or is it left, or right? And when we get called in, we usually already have, we're sort of cheating a little bit because we have blood cultures, they are positive, mostly staph. Staph is the number one organism that will seed your musculoskeletal system.

So, we went in and asked, where was the scratch? Did you get scratched? Did you have a splinter? Did you have any wounds over the past month that you forgot to mention? And then in the vast majority of cases, they say, "Oh, yeah, let me show you, this scab, I couldn't get it to heal for 10 days. And then I got this sudden onset pain in my back on the left side." And, you know, lo and behold, staph entered through the scab, the wound before it scabbed, seeded the spine, and then it's easy to put, you know, the route together. So, it makes us look really smart, whereas it's actually a very simple route.

Steven Gordon, MD:

Thank you. I'm wondering, you know, similarly, as many of us are getting up in age and maybe, you know, we'll get a prosthetic joint or things of this nature, not to scare people, but can you give us advice for either the clinician and/or the patient with a prosthetic knee or hip? What are the signs that couldn't be more subtle that you'd be worried about excluding infection in that joint? And how common is that and where do we usually see that under what circumstances?

Maja Babic, MD:

So, there's two groups of these prosthetic joint infections. The first group is the one that follows the placement of the prosthetic knee or hip. And that is marked by poor healing. That's why the orthopod really wants the patient to be in their best shape before they take them to the operating room, before they decide to place this hip or knee. Knees are a little more susceptible to infection than hips are, this early on. And it depends on the wound healing, the healing capability of the patient. Those are early infections, the wound never heals, it continues to drain. That is a bad sign. These are infected from the get-go because the envelope is not healthy, or healing ends up being multiple surgeries. But they can be prevented if, you know, the patient is given all the information ahead of surgery with regards to controlling their diabetes, getting their weight as low as possible to avoid the issues with healing.

And marked progress has been made with optimizing patients prior to it, because we know what happens if the healing is faulty. If everything goes well, the other group of prosthetic joint infections are the ones that get hematogenous seeded which means that there's a bacterium that enters either through skin or mouth flora and then it through the bloodstream, gets stuck on the artificial joints. Artificial joints are very sticky, bacteria will establish themselves if they enter the bloodstream. The clinical picture is somewhat similar to a native joint infection because those are acute, it's mostly staph and the prosthetic joint blows up, it's swollen, it's throbbing, and it progressively hurts more to bear weight on it. If the organism is wimpy, like a cousin of staph that covers our skin, and that is not very aggressive, it can sit in the joint for longer.

Those are these chronic prosthetic joint infections. And we never know, maybe it made it in during the time that it was placed or not, but they will bore their way out because they don't cause a septic picture. The patient is not acutely ill, it's months or years sometimes of pain. And in the end, there's a pimple that opens up and it looks like proud flesh, and it starts draining. This is a chronically infected joint, that one needs to be taken out, there is no salvaging of that joint. The acute ones in which the patient gets alarmed immediately. So, they are systemically ill, which means they have a febrile illness, shaking chills, and a blown-up joint. If they make it within a week to the orthopedic surgeon, we still have hopes of salvaging that joint. Then, it is just a wash out of the joint and antibiotics. And we have some success in salvaging those. So, the patient gets a chance to retain their prosthetic joint. If there is a chronic open draining sinus, that is a takeout.

Steven Gordon, MD:

Which as you mentioned implies a big procedure. I'm wondering too, Maja, I mean, not all joint failures are from infection, is that correct in saying there are other differentials of, let's say hip loosening or things of that, can you just explain how you kind of exclude those or what the process would be in terms of, for a patient where you want to exclude, you're not 100 percent certain but you want to exclude non-infectious versus infectious?

Maja Babic, MD:

Well, the clinical picture is usually different. They're not febrile. They're not systemically ill, it's just a progressive loss of function and gnawing pain, but then we get help from musculoskeletal imaging, it is relatively easy to recognize when it's one of these maybe, it's known in the public as metal-on-metal disease, metalloids. And the orthopods are pretty skilled in recognizing that and then not to underestimate our Path friends, they in the end give us the answer of, uh, if this is just wear and tear, or infection. The picture gets muddied if we end up with organisms that are very indolent, which means that they really don't cause many infections like p. acnes, or cog-negative staph, it is always a question, has this organism contributed to this process or not?

In the vast majority of cases, I would say they're just contaminants during the time of X planting of the failed prosthetic material. Not to say that shoulders are the only prostatic joints where p-acnes, unfortunately, is very frequently in, found in the cultures more in men than in women. Those are organisms that live in the bulb of our hair follicles. So, the surgeon can sterilize the surface of the skin and get rid of staph aureus, or big bacteria that are on the surface of the skin. But unfortunately, we have not gotten to that advanced point that we can sterilize every little hair bulb, and p-acnes manages to sneak its way in during the surgical cut, especially in, you know, men who have more chest hair, and unfortunately the shoulder is covered with very little of a subcutaneous envelope. So that's a risk with shoulder replacements.

Steven Gordon, MD:

Wow. Thank you. I'd like to pivot now maybe to antimicrobials, your approach in terms of obviously once you have a diagnosis, or maybe not, the roles of potential. Which ones do you feel are kind of appropriate, or does everyone need IVs for a certain amount of period in terms of this? Just kind of how you approach your prosthetic joint infections and other infections in terms of the most common antimicrobials that you're using.