Stem Cell Injections for Osteoarthritis May Not be What You Think
What You Should Know Before Paying for Treatment
For most people, the phrase stem cell therapy probably evokes a sense of cutting edge science, imagery of researchers in shiny white lab coats, tenaciously moving different color solutions from one test tube to another. However, the reality is that most so-called “stem cell” therapies for osteoarthritis have little scientific evidence to support their use and are obtained using pretty primitive techniques.
There have been numerous arguments written for and against the use of stem cell injections for osteoarthritis over the years. Unfortunately, these arguments often spiral into convoluted discussions about whether the treatments work, whether they are worth the $1500–5500 doctors are charging for them, and even whether they should be called stem cell treatments in the first place. One thing that’s gotten less attention is the treatment itself. Before we ask whether we should be using these treatments, it might be worth taking a step back to ask how these treatments are made.
The Basics
Stem cell injections in the United States come in two basic flavors: Treatments from bone marrow and treatments from fat. Neither type has undergone the rigorous process of review by the food and drug administration (FDA). This is because doctors giving these treatments claim that they are “minimally manipulated” and/or qualify as “homologous use”.
Understanding what this means is tough for many clinicians (much less the average layperson) to get straight. The reason these definitions are so tricky is partly that the labels have less to do with science than the wording in FDA regulatory documents. If you are feeling ambitious, you can read the FDA guidelines here.
I’ve also briefly summarized the topic in one of my prior articles on injections for knee osteoarthritis. However, the important thing to understand about today’s direct-to-consumer “stem cell” therapies is that they contain a lot more than just “stem cells”. This is because once you take blood or fat out of the body and grow it in a dish to isolate a specific type of cell (what scientists refer to as culturing), the treatment no longer qualifies as “minimally manipulated”/“homologous use”.
It should be noted that there are (and have been) stem cell treatments that don’t fit the description of stem cell therapy that I have provided so far. For example, there have been clinical trials that have used cultured cells. There have also been a handful of doctors that have chosen to ignore the regulations entirely. And some probably still do.
The New York Times has a good article highlighting the “Wild West” of stem cell therapy which I’d encourage you to check out for more on this. For the sake of simplicity, I’ll keep my discussion to treatments that could conceivably qualify as “minimally manipulated”, “homologous use.”
These treatments comprise the vast majority of today’s direct-to-consumer “stem cell” market in the United States. Moreover, these treatments have the added benefit of being pretty easy to understand conceptually, as the methods used to make them are fairly simple.
Bone Marrow-Based Therapies
Bone marrow is a soft, gelatinous substance found in bones. It contains the tissue that produces new blood cells. The procedure to obtain bone marrow is often described as “mild”, or causing only “minimal discomfort”. Make no mistake, however; this is no blood draw. In order to access the marrow, your doctor needs to go through the bone, and that often means drilling into the hip.
Once obtained, the marrow can be turned into something that can be marketed. This is done by putting the bone marrow in a tub, spinning it around in a circle until it separates into layers (what doctors refer to as centrifugation), and then pipetting it into another tube so it can be injected.
If this sounds like the kind of stuff that you would do in high school science class, that is because it is. While clinics offering these treatments often tout specific equipment or additional processing steps that make their treatments special, the basic isolation protocol remains largely the same from clinic-to-clinic.
Fat-Based Treatments
The process used to obtain fat starts with something called lipoaspiration, which is probably best described as low-tech liposuction. The process goes something like this: You show up to a clinic, have some numbing medicine injected into your belly, and then a needle is moved back and forth under the skin to break up the fat.
The principal difference between lipoaspiration and liposuction is that: (1) A syringe (not a vacuum) is used to suck out the fat, (2) the amount of fat removed is comparatively small (usually only 2–8 tablespoons), (3) you will be fully awake, and (4) the doctor performing the procedure (usually an orthopedic surgeon or primary care doctor) will have less experience with liposuction than your average plastic surgeon.
I am not aware of patients reporting major complications from the lipoaspiration procedure, but prospective patients should understand that no surgical procedure is risk-free.
Once the fat has been removed, things get interesting. The raw lipoaspirate (aka — the fat that was just sucked out of the belly) needs to be washed and broken up so that it can be ejected through a needle. This is usually done by passing the fat back and forth through a wire mesh using two syringes, or by putting the fat into what can only be described as a glorified protein shaker.
Regardless of which technique is used, the resulting “treatment” is a bunch of little fat nuggets that your doctor will end up injecting into you. Some clinics add additional steps, including a centrifugation process similar to what is used to make bone marrow-derived therapies. However, just like bone marrow “stem cell” therapies, the basic method used to make the treatment is pretty much the same.
Final Thoughts
So, should you get a “stem cell” injection if you have osteoarthritis? Outside of a reputable clinical trial that is willing to provide the treatment free of charge, I wouldn’t advise it. Even if we start with the premise that these treatments are safe (which they may very well be), the current research doesn’t really give us good reason to think that they work better than similar injectable therapies.
Granted, this doesn’t mean that direct-to-consumer “stem cell” treatments DON’T work. In fact, if you decide to get the treatment, your pain will probably lessen. The problem is that this improvement is likely just a manifestation of the strong placebo response that is associated with injecting something into the joint.
In other words, if your doctor had injected water into your knee and told you that it was stem cells, it probably would have worked just as well. In the context of conflicting information from doctors, high out-of-pocket costs, and a debilitating disease like osteoarthritis, the decision to have treatment is understandably difficult for most patients. Ultimately, each person will have to come to their own conclusion. If nothing else, at least now you have a better idea of what you are paying for.
