Friday, March 26, 2010

Is This an Epic Battle To Mimic the Disc?

Hydrogels have been used in breast implantation, dressings for burns and soft-tissue, topical drug delivery and in contact lenses. The effects of polyvinyl alcohol and (PVA) and polyvinyl pyrrolidone (PVP) have been studied for many years indicative of this materials versatility and ability to mimic a degree of flexibility similar to natural tissue. Scientists have been studying the effect of these co-polymers for many years, especially its potential in the spine. Some of the original studies focused on the replacement of the nucleus pulposus (NP) in the intervertebral bodies of the lumbar spine. These studies analyzed how dehydration affected the mechanical behavior of rehydration gels demonstrating the feasibility of nucleus replacement.

Lumbar discectomy has been proven to be an effective therapy for decompression of patients with herniated disc. So the question was asked, can the nucleus pulposus be regenerated, or as TSB would say remodeled? By identifying the viscoelastic properties of the nucleus pulposus the objective was to create a scaffold capable of integration without mechanical compromise. Many scientists believe that the swelling properties of blending PVA and PVP might allow spine surgeons to replace the NP endoscopically vis-a-vis a posterior approach.

Over the past ten years, companies have raised a tremendous amount of capital, and have also burned through an incredible amount. Some of it for research, some of it for marketing and of course some of it for its own personal use. Yet, the question, must be asked, is there a viable market of this material in spine? Some of the companies that surfaced believed if they could prove this materials efficacy, a windfall would occur. But somewhere along the beaten path it seems that the market for this material, as originally intended, is not as large in spine as it may be in other segments of medicine. So the question must be asked of our readers, is there hope for this material? And, how large of a market exists? And, do some of these companies stand the chance to execute and capitalize on their strategic objectives? Or, are their expectations greater than the reality that awaits them? TSB wants to know what our readers think?


  1. What makes you think the NP needs a scaffold?

  2. The disc can be regenerated if you catch it early. To take a completely degenerated disc and try to restore full function would be difficult even with some sort of scaffold. If you introduce cells early, not only will the degeneration stop, it will actually regenerate without a scaffold. The same is true with OA. Early introduction of cells into the joint will break the degeneration cascade. Vet-Stem, uses adipose tissue derived cells and has seen incredible results with horses and small animals. The use of autologous cells will revolutionize orthopedics and spine and all of medicine for that matter. The only question is how it will be introduced into a model of disease management. Early interventional regenerative medicine will need to take place prior to complete failure; unfortunately this is not the way our system works. Our surgeons mitigate pain until the solution is replacement or fusion. Stem cells will turn that on its head. This will happen for the progressive surgeons who recognize it first. Remember arthroscopy? Remember the days when no surgeons did it? I do. Not until the public demanded it was it covered. Today is a new day however…did Alinksy say anything about stem cells? No? Well don’t expect it anytime soon with this administration.

  3. Histologic and macrophotographic studies of the endplate in degerative discs shows a thickend endplate adjacent to the disc space. The postulation is that the thickened endplate eliminated the nurtrient flow to the disc resulting in the desciation of the disc tissue. Is this a case of "cart before the horse"? Did the disc desicate because of the thickend endplate? or did the endplate thicken as a response to the desicated disc..? What is the right amount (if any) of preparation needed in the disc space?

    Either way, I think that the next innovative leap in spine surgery will take place in the biologic realm. For the last 40 years the innovation has been by and large of a mechanical means. Fusion devices, mechanical discs, posterior hardware.....Like it or not bone growth materials (OP-1, InFuse et al...) are at the for front of the next innovative leap in how we treat patients with back pain. The stimulation of a desired biologic response in order to re-grow a specific desired tissue in a specific desired location isn't far away. Many companies are working diligently to find just the right cocktail / magic potion to put in the disc space...the question then do you keep the material in place long enough to get the desired result or how long does the magic potion need to stay in place? Will a collagen sponge be the carrier of choice or will something else be needed. In either case, I can't see the carrier or the length of time present being a stumbling block to the innovation. Chemistry is chemistry...there are plenty of brilliant people in this industy who can figure out the proper way to deliver a product. Especially one that could be such a game changer.....I think the key to these new products will be the regulatory side of the equation. Will such a product ever see the light of day given the regulatory environment? Will Joe Q Public demand approval and subsequent coverage for these products? Time will tell I suppose. Good luck to those working towards this innovation. I can't wait to use it (once's it's proven) in my practice.

  4. My money right now is on NuQu from ISTO Technologies. I think it makes a lot of sense looking at their technology compared with others like OP-1 and GDF5.

    The disc (annulus and nucleus) are made up of Type I and Type II Collagen. My thoughts are that an injectable that is derived from juvenile chondrocytes will possibly have the best outcome. These juvenile cells are immune priviledged and they are of mysenchymal origin.

    They are already down the lineage and can only become Type I or Type II Collagen. Unlike an undifferentiated stem cell, the juvenile chondrocyte will not turn into something else like bone, fat, muscle etc.

    The advantage with juvenile chrondrocytes is that they will remain viable in the disc space. It is an avascular area and BMP's cannot survive in that environment.

    The NuQu pre-clinical data looks outstanding. I think this Company has a great pipeline and they are looking like a potential big player down the road.

    I have been using their bone graft extender for almost two years with excellent results. I perform many adult deformity cases and the InQu product has been outstanding in the posterolateral gutters.

    I think that biologics are the way of the future and as a spine surgeon I would be happy to see regenerative and restorative therapies begin to replace many of these procedures where we have to rely on titanium implants for success. I think we will look back 10 years from now and we will all say that we can't believe that we used to perform so many of these invasive procedures with plates, screws, and rods.

    I think that the patients will help drive something like this when it becomes available. I also believe that the insurance companies will support this, only if it is a cost savings when compared with a fusion or artificial disc replacement. I am looking forward to delivering this option to my patients when the time comes.