Regenerative Medicine
By Faith Coleman and Alex Strauss
The American population is aging more rapidly than ever before. According to US government projections, by 2030, more than 20 percent of US residents will fall into the 65-and-older age group. That compares with 13 percent in 2010 and just 9.8 percent in 1970.
As this growing group searches for ways to restore lost function and remain physically active, a new science has emerged to support them. It is known as “regenerative medicine”.
Regenerative Medicine: A Brief Explanation
Coined by futurist Leland Kaiser of the Kaiser Institute in a 1992 paper, regenerative medicine is defined as the "process of replacing, engineering or regenerating human cells, tissues or organs to restore or establish normal function.”
Stem cells, undifferentiated biological cells with the power to differentiate into specialized cells, are a key component of regenerative medicine. These cells, which in developing embryos become all the tissues of the body, can also be found in the bone marrow, adipose tissue, and blood of adults. Globally, scientists are hard at work on the development of techniques that will utilize these powerful cells to heal injuries, regenerate damaged tissues or even produce entirely new organs.
“Regenerative medicine might be the biggest advance in healthcare I’ve seen in my thirty years as a physician,” says Walter Carlson, MD, MBA, a surgeon with Orthopedic Institute in Sioux Falls and a Clinical Professor with Sanford USD Medical School. Carlson has been incorporating stem cell therapy into select spinal fusion surgeries for the past two years.
Stem Cells in Orthopedics
Promising results have already been reported using stem cells in the treatment of conditions ranging from incontinence and tendon wear and tear to stroke, Parkinson’s, cardiac insufficiency, and kidney disease.
Increasingly, regenerative medicine using adult stem cells is also playing a role in orthopedics. Many musculoskeletal conditions have few therapeutic options beyond the conventional approaches, but stem cell therapy - especially when it utilizes the patient’s own cells - offers the promise of less invasive tissue repair, faster healing, and, in some cases, the ability to delay or even avoid joint replacement surgery.
“One of the things I like most about it is that it is not dangerous,” says Dr. Carlson, a graduate of the University of Minnesota Medical School and a longtime regional leader in orthopedics. “Our primary mandate is to ‘First, do no harm’ and this fits into that.”
Although spine surgery and total joints are the focus of Dr. Carlson’s practice today, he was also fellowship-trained in pediatric orthopedics at Texas Scottish Rite Hospital for Children in Dallas and was instrumental in bringing the Shriner’s Hospital for Children complimentary screening clinic to Orthopedic Institute. Dr. Carlson is the first OI surgeon to incorporate into his practice the use of autologous adult stem cells to treat degenerative disease of the spine.
“I was looking for ways to improve the quality of the fusions I do in the lower back,” says Carlson, who recently performed his 100th successful, stem cell-augmented spinal fusion. “In the past, there have been many different ways to do that with varying levels of success.”
One of those ways is to place a section of pelvic bone (which contain some stem cells) over the unstable vertebrae to improve the likelihood of a successful fusion. Not only does the technique require the patient to be in surgery and under anesthesia longer, but it can be painful and carries a risk of bleeding, infection, and a longer recovery.
A second option, developed to avoid some of the pain and risk associated with bone transplantation, is to use bone morphogenetic proteins (BMPs). But Carlson says these growth factors, which can induce the formation of bone and cartilage, also have their drawbacks.
“The FDA has not approved them for this application. They are also very expensive and there are potential complications such as nerve irritation, so we have moved away from that,” he says.
The Procedure
Instead, Carlson now offers select patients the option of enhancing their spinal fusion procedure with a dose of their own stem cells.
Mesenchymal stem cells are of particular interest in orthopedics because of their ability to differentiate into both bone and cartilage. While these cells have been isolated from adipose tissue, periosteum, and synovial linings, Carlson prefers to extract the cells needed to support spinal fusion from the stem-cell rich marrow of the iliac bone.
During the spinal fusion procedure, while the patient is under general anesthesia, Dr. Carlson aspirates about 100 cc of the liquid bone marrow (more for a multi-level fusion) and passes the syringe to a technician who performs the centrifugation. Preparation requires only about 20 minutes, after which a concentrated dose of about 15 cc is applied to a scaffolding product at the graft site, enhancing the environment to encourage consolidation of the bone.
Not only are the autologous cells safe for patients (and FDA approved), but harvest to application requires only a single procedure, making the technique more efficient and safer than the multiple procedures that may be required when cells are extracted from a different region.
“This is not the fountain of youth or the Holy Grail,” cautions Dr. Carlson. “But even at three to six months, I’m seeing a nice development of bone where I want it to be to help to stabilize and fuse the spine. This has been the experience of others around the country, as well, and the literature now supports the idea that stem cell supplementation in lumbar fusion is equal to or better than other techniques.”
Some stem cell procedures also use the patient’s platelets, which layer out in centrifugation. They may be injected into the surrounding soft tissue in the surgical area. Use of the platelets has been shown to reduce inflammation related to the surgery, may decrease recovery time, and help inhibit scar tissue formation.
Stem Cell Therapy For Other Clinical Applications
Not every patient with back or joint pain is a candidate for stem cell therapy, but many are. While Dr. Carlson has focused his stem cell therapy efforts on spinal fusion candidates, centers around the country are already branching out, applying the therapy in the treatment of arthritic knees, hips, ankles, elbows and other joints. After a visit to the Texas headquarters of OI’s chosen stem cell harvesting/processing system (Celling Biosciences, Inc.), Carlson says he believes that these other applications could easily be offered in Sioux Falls.
“We have gained a level of expertise here at OI, so that we can offer this here if someone is interested. We can also be a resource for patients who want to explore all the options. Many patients may not realize that this is even possible in Sioux Falls,” says Carlson.
Regardless of what area of the body is being treated, stem cell therapy may be an option for people with arthritic conditions who present with pain, but are not yet ready for full joint replacement or another surgical procedure. Often, such patients are offered cortisone injections or a synthetic lubricant such as Synvisc. “Those are not a cure-all, nor are they 100 percent effective, although they may relieve a patient’s pain for a time,” Carlson says.
Eventually, many of these patients do end up needing surgery. Although stem cell therapy has not been proven to be more effective in the short run than other nonsurgical approaches, it does offer one very distinct advantage.
“In addition to reducing inflammation and pain and improving function, there is also the hope that stem cells might actually help restore some of the patient’s tissues back to a more normal state,” says Dr. Carlson. “I think before I would have a big back operation, I certainly would try this, if my surgeon felt like I was an appropriate candidate.”
Is There a Downside?
Perhaps the biggest downside to this investigational therapy is the fact that, as with other emergent techniques, it is not covered by insurance. In the case of lumbar fusion, stem cell supplementation does not necessarily add to the cost of the procedure since it can replace an alternative like BMPs or bone transplantation. But the same is not true of other joints. A patient who wants to try an injection of stem cells into their knee or hip, for example, could expect to pay $5000 to $6000 out of pocket.
“If a physician has a patient who is having pain in their back or is having trouble with knee or hip pain and they’re not quite ready for a joint replacement, it certainly would be worth discussing with them,” says Dr. Carlson. “The key is they are going to have to be able to pay for it.” Carlson says we will work with patients who are interested in the technique to help make it possible.
“Even if they buy themselves two, three, or four years before they need a total joint, many feel it’s worth it,” says Dr. Carlson. “This is the future of medicine and the possibilities are really exciting.”
References
1. Bahney CS, Miclau T, “Therapeutic potential of stem cells in orthopedics”, Indian J Orthop., Jan/Feb; 2012, 46(1):4-9
2.Schmitt A, Griensven, et al, “Application of stem cells in orthopedics”, Stem Cells Int., 2012, 394962