Rafael Nadal, the professional tennis player considered one of the sport's all-time greats, injured his knee in 2012. He received stem cell therapy for the injury and in 2014 underwent another stem cell treatment for a back injury. The treatments may have done the trick-in 2016 he went on to become one of the few male players in tennis history to record 200 Grand Slam match wins.
Another athlete didn't fare as well. In 2011, Indianapolis Colts quarterback Peyton Manning, suffering from a bulging disc in his neck that hadn't improved after three surgeries and months of physical therapy, traveled to Europe to try stem cell therapy. Unfortunately for Manning, it didn't appear to work.
If the growing direct-to-consumer marketing efforts are to be believed, stem cells have the power to cure nearly any condition or disease, including baldness, poor eyesight, erectile dysfunction, arthritis, autism, and multiple sclerosis. Stem cell therapy clinics have sprung up around the world, and there are more than 700 of these clinics in the United States alone. Perhaps the most popular application of stem cell therapy is to ease joint pain, with the hope of preventing or at least delaying the need for joint replacement. But is this just hype, or is there something to the treatment?
MARKETING WITHOUT EVIDENCE
For the most part, stem cell therapy lacks evidence, despite advertised promises of cures. It remains controversial, and the U.S. Food and Drug Administration (FDA) has cautioned the public against believing the hype. "Some unscrupulous providers offer stem cell products that are both unapproved and unproven," it warns on its website. While stem cell therapy may have the potential to treat a wide range of conditions, especially in cases where standard treatment is limited, the agency is concerned that some patients seeking cures or symptom relief may be vulnerable to potentially harmful-and, in some cases, illegally manufactured or sold-treatments.
The use of stem cells is not a brand-new phenomenon. Hematopoietic stem cell transplantation, for example, which involves transfusing autologous or allogeneic stem cells to reestablish hematopoietic function, has long been used in patients with leukemia or multiple myeloma. But this therapy has been well studied and is evidence based, and that is not the case for the stem cell treatments that are being heavily marketed, such as those for joint pain.
"Stem cells in knee joints is like the Wild West right now, and there are no definitive, well-powered studies showing the efficacy of this treatment," says Christopher Mendias, PhD, ATC, associate scientist at the Hospital for Special Surgery and associate professor of physiology and biophysics in orthopedic surgery at Weill Cornell Medical College in New York City. "We're preparing some studies in this area now, but so far there's no objective data to support their use," he says. "No insurance plan covers stem cell therapy for knee injuries. If I had to come up with a summary of advice for patients in this area, I'd say, 'Caveat emptor'"-let the buyer beware.
Another expert agrees. "The whole field has tremendous potential to heal difficult-to-heal tissue, and in orthopedics that's common," says Scott A. Rodeo, MD, attending orthopedic surgeon and clinician scientist at the Hospital for Special Surgery and professor of orthopedic surgery at Weill Cornell Medical College. "The general issue in this field is that the marketing is far ahead of the potential. We're just not there, as far as the ability to use cell therapy on a regular basis."
The concept of stem cells "is kind of sexy, and that's why the marketing is far ahead of the science and our current clinical data," Rodeo says. "You see the billboards, the advertising, but the vast majority of it has not been proven. While most of it is pretty safe, some people have suffered from significant complications." (The FDA notes, for instance, that one patient became blind following a stem cell injection into the eye; in another case, a spinal cord injection caused the growth of a spinal tumor.)
Despite the lack of evidence, stem cell treatment continues to gain traction. This year, midwestern grocery chain Hy-Vee started requiring some employees to visit a stem cell therapy provider as a prerequisite to receiving a knee replacement. Hy-Vee has contracted with Iowa-based Regenexx, a large provider of stem cell therapy. According to Regenexx's website, its treatments "use your body's natural healing agents to repair or mitigate damage by concentrating and focusing them at the exact site of your injury," allowing for "natural, efficacious healing without the need for surgery."
More than 100 employers now include Regenexx services in their health insurance plans, according to a report in the April 2 Kaiser Health News. Regenexx stem cell injections range from $1,500 to $9,000. A single knee replacement, in comparison, may cost between $19,000 and $30,000 in the United States. Several high-profile medical centers and health systems are also now offering stem cell and related therapies. Among them are the Swedish Medical Center, Seattle's largest nonprofit health provider; the Mayo Clinic; the Cleveland Clinic; and the University of Miami Health System.
Rodeo points out that bone marrow and adipose tissue are the most commonly used sources for cells, and there are a small number of true stem cells in them. "But only about one in 10,000 meet the criteria of being a true stem cell," he says. "The only way to use them effectively is to take the materials to a laboratory and do cell sorting to isolate these cells." Cell manipulation, however, is not permitted by the FDA at this time, and there are many reasons why, such as sterility and safety issues. But cell manipulation is permitted in other countries, such as South Korea, and that is where much of the research is coming from, Rodeo says. "Ultimately, as the field evolves, these [regulations may be] relaxed, but right now in other countries, there is a more permissive environment."
Although most U.S. stem cell treatments haven't been approved by the FDA, they are not illegal. However, the agency has begun to crack down on "dishonest" clinics that it says are skirting statutes and regulations and deceiving patients. Warning letters, for example, have been sent to clinics in Florida and California. In 2017, then FDA commissioner Scott Gottlieb issued a statement declaring the FDA's intent to step up its regulation of unproven and highly solicited therapies.
POTENTIAL FOR SYMPTOM RELIEF
But stem cell therapies are not completely without merit when it comes to orthopedics. According to Rodeo, treatments have been shown to help arthritis symptoms, and may have an antiinflammatory effect. "They can be symptom modifying but not structurally modifying," he says.
Kimberly Weiss, MSN, RN, CNS, clinical nurse specialist at the Hospital for Special Surgery, says that stem cell therapy helps patients improve functionality and movement when used for muscle- and tendon-related pain. "It helps relieve symptoms and prevent more damage," she explains. Weiss also notes that stem cell therapy can be a quick outpatient procedure with minimal downtime. "Patients just need to rest the joint afterward."
Heavy advertising and promotion make it likely that patients will ask nurses about stem cell therapy. What patients should be told, suggests Weiss, is that stem cell treatment is a new therapy and is not a cure-all, but it can be an option for some patients with tendon and muscle pain. "Patients should go to a reputable facility where studies have been conducted and where the staff has been trained to use [the therapy]," she says.
Rodeo adds that nurses should also emphasize that, while largely unproven, stem cell therapy is generally safe, but because it is typically not covered by insurance, it is unlikely to be recommended. "People are enticed by the widespread marketing," he says. "We need more data before these therapies can be used on a widespread basis."-Roxanne Nelson, BSN