Nikhil Verma, MD, Sports Medicine Surgeon, Midwest Orthopaedics at Rush; Professor and Director of the Division of Sports Medicine at Rush University Medical Center talks about stem cell rotator cuff repair surgery.
You are doing rotator cuff surgery in combination with the use of stem cells. So, what is the purpose of that?
Dr. Verma: Today there are a couple of problems that we have with rotator cuff surgery. The first is patients do not always heal as well as we would like. When we look at patients that have had rotator cuff surgery even though we repair the tendon and stitch it back into place, about 20 percent of the time it does not heal. The second problem is it does not heal with the normal interface between the tendon and the bone that we see in normal human anatomy. It heals by scar tissue which means even when the tendon heals patients can still have some functional deficit or mild persistent pain after surgery. The third problem is the recovery takes a long time. If you talk to anybody who has undergone rotator cuff surgery, they will tell you the recovery is about a year. They must be in a sling for six weeks and then work on getting their range of motion back, so they are not stiff. Then it takes six to nine months to strengthen the shoulder so they can go back to work and play sports. The reason that we encounter all these problems is because of biology. We are dealing with tendons that are typically degenerative. This is a problem that occurs mostly in patients over the age of 50. Over the time frame of life, the tendon becomes de-vascularized, which means the blood supply to the tendons starts to diminish and that can be accelerated in patients with hypertension, diabetes, or who smoke. As a result, even though we have stitched the tendon back into place and created an adequate mechanical construct, sometimes the body does not heal as well as we would like.
What is the purpose of adding the stem cells?
Dr. Verma: We have really maximized what we can accomplish from a mechanical standpoint and we have gotten good at understanding how to stitch it and get it as strong as possible. But what we have not been able to do is augment the healing process and I think that is the next generation of orthopedics, not just in rotator cuff surgery but across the board. How do we harness the body’s own healing potential to heal better, faster, and create normal anatomy? One of the ways that we do that is with stem cells or other biologic products. We do not really know for sure how stem cells work but the nature of stem cells is that they can become any cell. We think about this in organs where you take a stem cell and it can become a liver cell or a kidney cell, but in bones and joints it can differentiate into a tendon or a bone. More importantly it helps to signal the body to bring in the appropriate building blocks, biologic growth factors and other things that help create a normal healing environment. Essentially what we are trying to do is to rev up the body’s healing response and direct it so that it heals normally to create a normal interface between the tendon and the bone.
Have you seen any comparisons in healing or recovery time from the results of rotator cuff surgeries with the stem cell injections and without it?
Dr. Verma: One of the hard parts when we start using any of these biologic agents is that they’re typically experimental, which means we’re still at the very infancy of learning how to use them, when to use them, how to get them into the right place and how well they work. We designed a study here at Rush to determine whether stem cells help in the healing process following rotator cuff surgery because that is one of the major problem areas that we see biologically. We took two groups of patients and half got stem cells and half did not. They all underwent a similar repair surgery process and then we looked at their MRI scan about six months to a year after surgery. What we found is the group that got stem cells saw a marked improvement in the appearance of the tendon compared to the group that did not get stem cells. Overall, the patients whose tendon was healed was more favorable in the group that got the stem cells then did not get the stem cells. This is one of three studies that are published that have a very high-quality design where you take a control group and an experimental group and compare the two over time. They have demonstrated that stem cells have the capacity to improve healing after rotator cuff surgery. That is extremely exciting because it helps us know whether we are on the right track in terms of changing the way we treat these patients and potentially providing a better option.
Do you know what percentage of patients had this outcome versus the patients that did not?
Dr. Verma: When we looked at the two groups and compared them, the healing improvement was about 20 percent in the group that got the stem cells, which means that the tendon looked more normal. They were less likely to have a re-tear of the rotator cuff over time. Now the next step is to compare patients in terms of how quickly they heal and whether we can accelerate their recovery time so they can get back to their work or sports activities and their daily living activities.
Did you look at them at both six months and a year?
Dr. Verma: The patients in the study were followed from the time they had the surgery until two years with what we call clinical outcome scores, which means asking patients how are you feeling? How is your pain? We had many patients in the stem cell group that felt their pain got better quickly. One of the things that we have seen with the biologic products is they tend to decrease the inflammatory reaction and there is less pain immediately after surgery. The MRIs were done a year after surgery, and that is the time when we looked at the tendon critically to compare whether the healing was better, if the tendon appeared normal, and how the two groups compare to one another.
Did your patient David get the stem cell injection?
Dr. Verma: David got the stem cell and was part of the study. Now we are working on the patient follow ups. David was enrolled in the study and got the stem cells in one of his shoulders. About two years later he tore the other shoulder. As a result, he voluntarily elected to have the stem cells during that procedure because he benefited during his first surgery.
How do you think this will affect a patient’s quality of life when it comes to surgery versus if they had the rotator cuff surgery with stem cells?
Dr. Verma: There are two major ways that we can start to improve outcomes for patients following rotator cuff surgery. The first is we can start to accelerate the recovery timeline. Right now, if you take somebody who is a manual laborer or does physical activity with their arms or shoulders, they may take 6 to 8 months to get back to work. For athletes it can be anywhere from 6 to 8 months up to a year after surgery. So the first thing we’d like to do is accelerate the healing process so we don’t have to put them in a sling for six weeks and we can start to move them earlier and be confident the tendon is going to heal properly without diminishing the strength that we see from the immobilization time frame. The second issue is somewhere around 20 percent of patients may have a failure of their repair, and a percentage of those patients will need secondary surgeries that can be much more complex. Sometimes we must replace the shoulder and just throw out the rotator cuff completely. So, the idea is if we can make the healing more reproducible, we can decrease the risk of complications following surgery and the number of patients that need secondary procedures down the line.
What do you think not having those extra surgeries means for patients regarding being able to do daily activities?
Dr. Verma: The problem is when patients have a failure of their primary repair. Even though we do a second surgery we are rarely able to restore the shoulder to normal function, meaning that they are left with some strength, functional loss or inability to return to the things they love to do. Whether it is general work activities, sports, or difficulty with activities of daily living. The goal is to get it done right the first time and make sure the tendon heals properly. That is when we have the best chance of getting the patient maximal functional recovery so they can go back to doing all the things they love to do.
If somebody had surgery without stem cells, is it possible at that point to do the stem cells?
Dr. Verma: When we think about applying stem cells it is no longer being done through the study but rather at the discretion of the patient. Because the data is so limited most insurance companies including Medicare consider this experimental. So, it does fall onto the patient as an out of pocket cost. What we recommend is if they have large tears that have a higher risk of non-healing, have chronic tears with a risk of non-healing that have existed for two, three or four years, have medical problems such as smoking, diabetes, and hypertension where the blood supply to the tendon is not optimal, and in patients who’ve had surgery but have not had a good functional outcome or we are trying to repair the tendon a second time those are the patients that we typically talk to about the benefits of stem cells and why they may be a good candidate for a stem cell procedure.
Is there a group of patients that it would not be the best option for?
Dr. Verma: Right now, we know that younger patients with small tears have a high chance of healing. It is not clear yet whether we can offer a substantial benefit to those patients because their tendons heal reliably. In terms of true contraindications for stem cells, we know for sure at this point is that there is enough data to suggest that they are safe. These cells generally come from one’s own body. Our preference here is to use a bone marrow aspirate, which means we take a sample of bone marrow from the pelvis area. So, your own cells are being implanted back at the same time. There are minimal risks of complications with infection, which is extremely rare with the stem cell harvest or injection. The big issue it tells us is a patient should not have a stem cell procedure if they have some type of cancer or involvement of the blood where they don’t make cells normally, they’re making too many cells or they have a cancer that involves the blood system. That is when we say it is not appropriate to take your own cells, expand them, concentrate them, and then re-inject them.
Is there anything that I did not ask you that you feel people should know?
Dr. Verma: Commonly asked questions are how stem cells change the procedure? Does it take more time, and does it make the surgery more complex? One of the beauties is it is an extremely simplistic thing to do. When we put the patient to sleep to begin the surgery, we take a sample of their bone marrow from their hip which involves a small incision about five millimeters. We take about 60 milliliters of bone marrow and then it goes through a process where it is concentrated. There are special systems now that use centrifuges and other sorting capabilities to take away the normal blood material or other cells that we are not interested in. It concentrates just on the stem cells between three to six times. So, you go from a 60-milliliter sample of bone marrow to about a three to four milliliter concentrate of stem cells. Then at the end of the procedure we take away all the fluid from the shoulder and put a small needle in place and inject the stem cells directly where the tendon was repaired. So, it is a quite simple process and does not add any complexity for the patient. It does not increase the morbidity or complication rate for the patient and does not change the way we do the surgery or the way the patient rehabilitates afterwards.
How long is the surgery itself?
Dr. Verma: The surgery can be 45 minutes but could probably be shorter and 60 minutes is the average time. A complex rotator cuff surgery with an exceptionally large tear can take up to an hour and a half.
Are there several options where you can get the stem cells from?
Dr. Verma: One of the things we are learning about stem cells is how do we get them. It does not matter whether you are young or old but rather is your capacity to produce stem cells the same? And where should we take them from? Should we take them from you, or do we take them from a donor? Right now, given the infancy of this, we feel strongly that taking them from one’s own body is probably safest because we know we are not going to do harm. It is your very own cells that are coming back to you. There is no risk of rejection or immune reaction. We generally do it from the bone marrow. The two options for taking stem cells from your own body include your bone marrow which is typically done from the pelvis area but can be done from anywhere including long bones like the femur or tibia and even directly from the top part of your shoulder at the time of surgery. But the data at this point suggests we get the greatest number of cells taken from the pelvis. The second option is creating them from fat tissue. You take a small amount of your fat, separate the fatty tissue from the stem cells, concentrate them and re-inject them. The third option is donor stem cells. These are produced from placental products, although some companies are looking at cloning stem cells, expanding them in a lab and making them available for commercial use. Problem is its unregulated, so it is extremely hard to know what the concentration of the cells are, whether they are viable cells or whether it contains growth factors. So, until we get some clarity regarding how this is going to be regulated and what exactly these products contain, in my opinion it is safer to use one’s own stem cells if possible.
Interview conducted by Ivanhoe Broadcast News.
END OF INTERVIEW
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