Transcription:
Knee Pain: Diagnosing and Treating Cartilage Damage

Melanie Cole (Host): If you suffer from knee pain, you’re not alone. Each year, millions of people visit their doctors because of knee pain. My guest today is Dr. Brian Chilelli. He’s an Orthopedic Surgeon with Northwestern Medicine Central DuPage Hospital and Northwestern Medicine Delnor Hospital. Dr. Chilelli, tell us about the current state of knee pain today. What is the prevalence and societal impact of knee pain and what do we know about it that we didn’t used to know?

Dr. Brian Chilelli (Guest): Well I would say that knee pain is very common in the general population and there are various etiologies to knee pain. Some of those are traumatic following specific injury, but most often times is an insidious onset where someone will just develop pain in the knee and won’t really recall a specific injury and the pain can certainly interfere with daily activities and interfere with their workplace, so it has a big impact on society in general, whether it’s the workplace or there are special injuries outside of work.

Host: What are the most common conditions that cause the knee joint to breakdown or have problems?

Dr. Chilelli: Well the most common by far is certainly damage to the cartilage – the articular cartilage, which is the shiny coating on the end of the bones with the joint, and that’s certainly the most common. There are other structures in the knee that can be damaged or injured that can cause knee pain such as meniscus structures, which is the shock absorbers as well as various ligaments in and around the knee, but certainly we see a lot of cartilage damage that causes patient’s pain, and again whether that’s an acute traumatic injury or just a gradual wearing out of that articular cartilage.

Host: Tell us some symptoms. People get knee pain for all kinds of reasons, and if it is arthritis or degenerative in nature, what would they feel? What would send them to see a doctor at that point?

Dr. Chilelli: Most patients report a vague pain deep within the knee. Depending on where the injured structure or structures are, it could either be on the inside of the knee, which is referred to as the medial aspect of the knee or the outside of the knee which is referred to the lateral aspect of the knee or certainly deep within the knee and various areas of the knee can cause that location of their symptoms. They will typically present with an overall vague complaint of just pain, sometime an achy feeling. At times it can be sharp, especially with rotational movements or certain specific activities. We see a lot of pain with bending, kneeling, squatting, as well as using stairs, especially with damage to the cartilage behind the kneecap, which is referred to as the patella.

Host: What imaging studies do you use? How do you confirm that it is cartilage in nature as opposed to a tendon tissue or a musculoskeletal issue?

Dr. Chilelli: We typically will start with x-rays. It’s our first line evaluation in orthopedics for pretty much all conditions and someone with an isolated area of cartilage that’s damaged and causing their pain often time will have normal x-rays. Someone that has more widespread damage to their cartilage may have findings on their x-rays that are consistent with osteoarthritis or wearing out of the knee. We usually combine their history, what they tell us about their symptoms, combined with any mechanism of the injury, in addition to their physical exam and imaging to try to determine whether or not the pain is coming from the cartilage or elsewhere and we will also quite often resort to MRI, that’s our workhorse or our go to, to evaluate the integrity of the cartilage. Some patients are unable to get an MRI for various medical reasons and sometimes we can also utilize a CT scan, sometimes a CT scan with dye, which is referred to as CT arthrogram. So the initial evaluation consists of the x-rays and more advanced imaging as indicated depending on the physical examination, the history, as well as my interpretation of their x-rays.

Host: Dr. Chilelli, what’s the first line of defense? If you determine that there is cartilage damage or degeneration, what are you looking to first as far as nonsurgical approaches, whether that be ice, modalities, physical therapy, and then speak about when injection therapy might be used – the biologics that people are hearing about in the media.

Dr. Chilelli: Well the first line’s treatment for the majority of cases is conservative. I am a very conservative surgeon and we have some good data based on previous studies that have been performed that a lot of cartilage damage in the knee can be successfully managed with nonoperative means. We will usually start with physical therapy combined with activity modification as well as anti-inflammatory medications assuming the patient is able to take those from a medical standpoint and have no contraindications to that. That’s more or less the first line treatment. Other options include various types of injections, and historically the most common injections we have been giving these patients have been the various types of cortisone that’s usually mixed with a local anesthetic or what’s called a hydronic acid injection, another name for that is a gel injection, and those are typically used to either decrease inflammation that’s caused by the damaged cartilage or to provide a lubrication and decreased friction. Newer injectables are becoming available, and certainly the hot area of orthopedics and medicine in general is biologics in general and we’re seeing good emerging data looking at these, the various biologic injectable products, and to start off with one of the most well studied, within the past 5 to 10 years is actually PRP, which is platelet rich plasma, and that’s patient’s own blood that’s been spun down on a centrifuge and reinject it into the knee. The idea behind that is we have cells within that liquid that can decrease inflammation and to a certain extent, provide somewhat of a healing response. Other types of injectables on the market are various stem cell products and stem cell products are – there’s a wide variation in stem cells and what we’re calling stem cells. Most common is bone marrow aspirate but certainly stem cells can be obtained from adipose tissue – we’re seeing new data, looking at synovium, which is the lining of the knee joint as well as other areas that we can obtain these cells, and preliminary data does suggest that it could certainly improve patient’s symptoms; however, we’re still working on better, well conducted high powered studies to know more about exactly which stem cells are the best to use and what concentrations. In addition to the stem cells and the PRP, there’s other types of amniotic membrane injections that are on the market that had been proven to be efficacious as well, and those injections are not pure stem cells, but they do recruit the bodies of the stem cells to an area of injury or damage.

Host: Isn’t that fascinating what’s going on with the biologics. Really it is Dr. Chilelli. Now if the discussion, when all else fails, and the nonoperative management doesn’t work for a particular person, what does the surgery discussion look like? What types of procedures are available, as far as whether it’s chondroplasty or debridement or even a joint replacement? When does that discussion take place and what does it look like?

Dr. Chilelli: So usually in my practice that discussion takes place once the patient has failed nonoperative management. There are various types of procedures that can address cartilage damage or cartilage injuries, varying from minimally invasive, fairly quick recovery surgeries to fairly invasive long recovery surgeries, and the type of surgery that’s chosen depends on a lot of factors. Depends on the location of the cartilage damage. Where in the knee is it? Is it behind the kneecap or the patella or is it other areas of the weightbearing portions of the knee including the femur or the tibia? So the location plays a role. The size of it plays a roll as well. How small or how big is it? In addition, there are patient factors as well. How old is the patient? Not only chronologic age but physiologic age. What are their goals and ambitions and expectations? Are they active? Are they sedentary? So those will all play a role and sometimes these injuries or damage to the cartilage do require a simple knee scope initially, or an arthroscopy as we refer to it, and it’s a procedure that’s minimally invasive done through small poke holes that we’re able to visualize the damaged cartilage and sometimes smooth out loose fragments or flaps that can certainly help patient’s symptoms, but also gives us a better idea of the exact size and dimensions, and overall health of the knee, which some of that data the MRI doesn’t give us, and so that’s often times the first line surgical option and more advanced surgeries include various types of cartilage transplants, and those types of transplants can be either, what we refer to as autologous, which means it’s the patient’s own cells or the patient’s own tissue. For instance, I can take a small biopsy of their own cartilage at the time of that knee scope and send it off to one of the biologic companies at their laboratory and they can actually grow those cartilage cells in a lab which can be replanted into the knee. That type of technology is referred to autologous chondrocyte implantation and that’s to address any cartilage damage to grow new cartilage. Other types of procedures include Allograft transplantations, means that we take bone and cartilage from a cadaver graft and transplant into the patient’s own knee in the area that’s injured. These procedures can be performed in isolation or in conjunction with other types of procedures in order to preserve the joint and that’s true joint preserving surgery. Sometimes if there’s malalignment or the leg is not aligned properly, it can put too much pressure on one area, or the area of the cartilage transplant and therefore procedures such as osteotomies can be beneficial to straighten the leg in order to alleviate pressure from that particular area. In addition, we can perform meniscus transplants for patients who have had previous meniscus remove or if their meniscus is damaged to the point where it’s nonfunctional. So those can be combined with these various cartilage procedures, and in addition there’s a lot of research right now looking at how we can improve upon these current techniques and a lot of that research is looking at the biologics and how can we make this tissue that we’re growing in the knee or transplanting even better and more similar to the original cartilage.

Host: Wow it’s amazing information. Dr. Chilelli, wrap it up for us with your best advice for keeping healthy knees in the first place and what you would like us to know about cartilage damage in the knee, possibly using a brace if you’re a doctor that recommends using bracing at the beginning. What would you like patients to know if they start to suffer knee pain?

Dr. Chilelli: Well I think first and foremost, one of the things patients can do from a preventative standpoint is maintain a low BMI or body weight and live a fairly active lifestyle. I think that it’s beneficial for joints. For patients that have pain or discomfort and are suffering from a knee condition, I certainly think that braces can be used. Sometimes it may not change the structural damage in the knee but it certainly can give them some reassurance and get them through any kind of short term pain. In addition, I think it’s important to have patients be honest with what they’re feeling. Sometimes various joints can be painful for a short period of time, days, to weeks, to months and it may resolve. Those are minor sprains or minor injuries in the joint, but for pain that persists, that’s an indication that someone may need to see a specialist to have it further looked at because if pain persists for months or years, that could mean that there’s more damage being done. So I think living an active lifestyle, keeping the body weight down, but also being honest with their symptoms and seeing a specialist if these symptoms persist.

Host: It’s great information. Thank you so much for coming on today and sharing your incredible expertise on the knee and pain and all of those treatment options available. Thank you again. You’re listening to Northwestern Medicine Podtalk. For more information on the latest advances in medicine, please visit nm.org, that’s nm.org. This is Melanie Cole, thanks so much for tuning in.