I have a lot to blog about this morning with many subjects waiting in the cue, but every once in awhile a subject is pressing enough that it needs to be blogged immediately. This morning that subject is disc stem cell therapy. Yesterday a patient on a discussion board about biologic orthopedics jumped in on a complex expert discussion of stem cells to treat low back discs. While it’s easy to assume that patients have a good understanding of the complexity of spine care, I’m frequently reminded that they can get duped easily. Why? Physicians can spend a lifetime learning about the spine and still not completely understand it’s nuances. The smart physicians get to the point where they know what they don’t know, the not so smart ones assume they know everything there is to know. Such is the nutty world of emerging stem cell care for degenerative disc disease.
First, let me begin with a story of a message sent to me about disc stem cells. The patient wanted to know whether a physician who had taken a few minutes to look at his MRI and pronounced him an excellent candidate for an intradiscal stem cell injection was being truthful or just fishing for money. I answered that patient’s question with another question: If your car wouldn’t start and you texted a mechanic a picture of the car engine and he told you he knew exactly what was wrong and gave you a firm estimate of what it would cost to fix, would you trust that mechanic? Of course not! Cars are way too complex to diagnose via a cell phone pic and outside of a few things (like a pic of a thousand pound boulder sitting on your car engine block), no reputable mechanic would do this. The same goes for physicians.
Perhaps this gentleman’s MRI was like that boulder sitting on the car engine block in that it had some obvious finding that would allow the doctor to immediately diagnose the source of this patient’s pain? Regrettably, all too often, research studies have shown that outside of diagnosing an acute fracture or a huge herniated disc compressing the spinal cord, trying to determine the source of someone’s low back pain by looking at an MRI is no better than chance. In fact, if you’re a patient reading this post, if you’ve seen a few doctors and not gotten relief, the hard to accept reality is that an accurate diagnosis will take hours of physician time and not minutes. What if no doctor has ever spent more than a few minutes to look at your films and press on your back or even worse, what if you’ve only ever spent time with a physician extender like a PA or NP? Run, don’t walk from that provider’s office, i.e. find a new doctor who will.
Now to disc stem cell treatments. Many patients with severe degenerative disc disease believe that stem cells hold a magic bullet treatment for their collapsed discs. Why? In animal models, regrowing a new disc seems to be relatively easy. The problem is that every stem cell based therapy being used in clinic or that’s in clinical trials with real patients has not shown the same convincing results. A few have tried to slice and dice the data, but once you dive deeper into the study, an expert can see evidence of lipstick being applied generously to a pig. Why aren’t these human studies showing the same magic that was seen in animals? I remember a great conversation with a disc researcher who relayed what happened in a study of platelet rich plasma (PRP) in pig discs. He was excited to learn that degenerated pig discs seemed to be regenerating with PRP. His elation turned to frank depression when he realized that the saline injections were doing the same thing! Pigs, dogs, and rats are an awful animal model for human degenerative disc disease.
So after a decade spent injecting stem cells into human discs, what’s real and what’s B.S. with regard to DDD in 2014?Real:
1. If you have very select disc issues (a painful grade 3-4 annular tear on discography with good disc height), PRP or same day stem cells may help reduce your pain. 2. If you have severe DDD with a collapsed disc, no therapy being used today or in clinical trials currently will regenerate your disc. Not Real: 1. Any pain relief you get from a disc PRP or stem cell injection isn’t likely coming from regrowing you a new disc. A few patients may see some small positive changes, but many will not.
So if the claims are mostly not real, what other regenerative options are there? First, you can see small positive changes in a degenerated and bulging disc that has good disc height without injecting the disc, bit instead injecting 3rd generation platelet growth factors into the area between the disc and the spinal nerve (transforaminal epidural) and ligaments. Why the ligaments? Because a major player in DDD is instability due to lax ligaments. You can also see resolution of large disc herniations with just an epidural of third generation platelet growth factors. Finally, highly selected and cultured stem cells from bone marrow injected in a precise injection will likely get rid of persistent disc bulges pressing on nerves in most patients.
Why not just inject the disc? Putting a hole in the disc should never be a first, second, or even third line treatment. While it may be the answer for some patients, it’s significantly more invasive than not injecting the disc (i.e. placing growth factors epidural or into ligaments). In addition, at least one large study has suggested that this small hole could cause more disc degeneration in the long run. While for the right patients this approach may be a God send, for many it’s unnecessary and if the right things aren’t injected in the right disc, we may see more and not less disc degeneration. In fact, several recent studies have shown that common contrast agents used in discography (the procedure that puts the stem cells into the discs) are toxic to the cells inside the disc (study 1, study 2, study 3). So when stem cells are used in discs, they need to be placed such that these contrast agents are washed out of the disc.
The upshot? Getting to an accurate diagnosis of what’s causing pain in most complex patients takes hours of physician time and not minutes. Don’t get bamboozled by any physician who spends a few minutes looking at your MRI and proposes invasive care based on that picture. Disc stem cells hold some promise for treating the right patients, but no clinical study to date has shown that a patient with a collapsed and degenerated disc will regrow a new disc with a magic stem cell injection!