[Ksayles]

#20493

Dear Dr. Corenman,

My name is Kendra. I am a PhD student who is actually slated to come to work at SPRI with Dr. Huard’s new lab there. I am interested in dedicating my research career to designing better solutions than spinal fusion and similar means of immobilization of the spine for people who have DDD, experienced vertebral trauma, etc. I would like to design modalities that can correct the diseased or injured site while still being able to fulfill the qualities demanded of the native, healthy spinal structures (support, motion, etc.).

I would like to know if the IVDs are left intact and preserved using a posterolateral fusion technique. Also, I have read documentation of some fusions being “reversed” and artificial discs being implanted (although I believe this was done with patients having undergone anterior approaches/fusions). In someone who was fused owing to vertebral fractures which soon after heal completely, what are the main barriers to a fusion being reversed? Could the facet joints not be rescued?

Thanks Very Much!
Kendra Sayles

[Donald Corenman, MD, DC]

#20510

Welcome to the research institute! Look forward to meeting you.

The discs can be left intact with a posterolateral fusion but are generally nonfunctional with a successful posterolateral fusion. The fusion cannot be reversed to an artificial disc as the facets are no longer existent. These joints need to be destroyed to crease the fusion in the first place.

Most current fusions are TLIFs which fuse the disc space as well as the posterolateral region.

Artificial discs generally work well in the cervical spine but are not as durable in the lumbar spine due to the mechanical stress and the approach through the belly.

Dr. Corenman

PLEASE REMEMBER, THIS FORUM IS MEANT TO PROVIDE GENERAL INFORMATION ON SPINE ANATOMY, CONDITIONS AND TREATMENTS. TO GET AN ACCURATE DIAGNOSIS, YOU MUST VISIT A QUALIFIED PROFESSIONAL IN PERSON.
 
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.

[Ksayles]

#20683

Thank you, Dr. Corenman.

Just a few more questions to clarify…

If an interbody fusion is not done in, say, the C-spine and the discs are left intact, and morselized laminectomy bone from other regions such as the T-spine is packed into central regions of cervical lamina (those that are remaining) and also packed into decorticated facets to create the C-spine fusion, my curiosity is why some of this bone cannot be ground off to restore movement ability over motion segments.

I understand that grinding on or otherwise “roughing up” a bone surface promotes osteoblast activity and the synthesis of more mineral bony matrix, but if bone creating the fusion is ground off the facets and the lamina that remain, can a barrier that inhibits the bone growth be placed over the areas from which the bone was ground off? Can a bone wax, in other words, be used, and if the facets have been decorticated can they be remodeled and/or remobilized? I assume that decortication of the facets does not entirely destroy the actual facet joint surfaces themselves?

Maybe I just need to come observe some surgeries, haha! That would be really helpful.

My Best,
Kendra

[Donald Corenman, MD, DC]

#20684

There was a time about 30 years ago called the “rod long fuse short” days. These patients had a one or two level fusion with a three or four level instrumentation. At about one year, the rods were removed, expecting the unfused levels to return to normal. This did not happen. The unfused but immobilized levels became stiff and painful. It turns out that motion is needed to keep facets or other joints healthy.

A mild example of this effect is seen with simple immobilization of the elbow for six weeks. A forearm fracture sometimes needs a cast that includes the elbow. When the cast comes off, the elbow is very stiff due to the immobilization even though this joint was uninjured.

Barriers can often prevent fusion (or bone formation). In fact, I see patients that have had prior unsuccessful surgery resulting in a pseudoarthrosis (non-union). Many of the times, the reason this occurs is due to poor preparation of the two bony surfaces. Without meticulous preparation (careful removal of all soft tissues to uncover raw bone surfaces), the two bones won’t heal together.

Bone wax is a substance that will prevent fusion. Remember that when a surgeon attempts to fuse a facet joint, he or she will remove all the cartilage off the bone joint surfaces. This cannot be replaced (at least at this times but I have ideas about this that I am developing). The disc in front will also become stiff while held still due to the instrumentation that typically is included to immobilize the fused segment.

Dr. Corenman

PLEASE REMEMBER, THIS FORUM IS MEANT TO PROVIDE GENERAL INFORMATION ON SPINE ANATOMY, CONDITIONS AND TREATMENTS. TO GET AN ACCURATE DIAGNOSIS, YOU MUST VISIT A QUALIFIED PROFESSIONAL IN PERSON.
 
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.

[Ksayles]

#20703

Thank you for this information Dr. Corenman. Very interesting! I truly appreciate your continued time and consideration in responding to me.

Do you think that bone marrow aspirate or PRP injections into the decorticated facets could help restore motion if the fusion was not done many years ago…or would it be a lost cause?

I would be very interested to hear your ideas about replacing cartilage on articulate surfaces, that is VERY much in line with some of my passions.

I do realize that surgeons have a generally reliable and extremely widely implemented treatment modality in fusion; however, I think that as medicine progresses we can do better to treat degenerative pathologies and trauma to the spinal column while preserving more of the innate qualities and function of the spine. Right now, to treat a given problem we obviously eliminate the natural function of these joints by fusing, and fusing itself can potentiate other problems. I have met many people who say they are more dissatisfied after their fusion than before, and wish they would never have gotten it done. Of course, I recognize this is not the case the majority of the time, but my empathy still lies with these folks. This is what piqued my interest in regenerative medicine: I wanted to spend my career working toward the goal of designing modalities to reconstruct bone, cartilage end plates and discs from a biological basis (i.e. pluripotent, multipotent stem cells). My ultimate hope is that one day, the acutely injured or diseased site itself can be directly treated and/or actually replaced with tissue-engineered constructs that do not lend themselves to concerns of immunogenicity, thereby bypassing the need to fuse the site(s) of concern in addition to subsequent levels.

At this point, I have learned that the mechanics of the spine are very complex, and that the practical surgical implementation of some of these therapies I aspire to work on is clearly a tremendous part of the equation. What good is it to work on developing some novel treatment if it cannot be practically applied, right. Hence, I am considering going to med school after I finish the doctorate to eventually get into spine surgery – I would want to continue to actively engage in research during my career as a spine surgeon, perhaps working in a large research-intensive academic setting. Based on all your experience in this elite industry, do you find that most novel research focused on the spinal column is derived from spine surgeons who have a research component to their career and/or are partnered with large medical device corporations?

I am very, very passionate about advancing options in spine surgery, so your opinion on this front (sticking with just the PhD or moving on to a 10-11 year track in med school to become a spine surgeon) would be of great value to me as well. I know that being a surgeon would give me a much, much deeper understanding of what is needed in conjuring research designs, and likewise impart a concise ability to judge the practicality of potential therapies in real-world application. I feel the doctors in the OR who are hands-on with these complex cases day in and day out are best equipped to design the next generation of therapies…who would know better than surgeons such as yourself?

What is your appraisal of this article?
http://www.drkennethlight.com/blog/dr-light-performs-the-first-spinal-fusion-reversal-in-the-u-s/

Again, thank you so much for all your input and the information.

My Best,
Kendra

PS – There is a contractual hang-up that has prevented some of us from moving up to Vail thus far, but I am hopeful that it will be resolved by the end of the year and we can come on up after that. I would be very pleased to meet you in person.

Thank You Again!
Kendra

[Donald Corenman, MD, DC]

#20704

Bone marrow aspirate or PRP injections into the decorticated facets will not help to restore motion. You need to have two cartilaginous surfaces to prevent friction and allow a gliding motion (or possibly something that I am developing). PRP has growth factors but nothing that will restore cartilage denovo. Stem cells certainly have the ability to grow hyaline cartilage but there still are real problems with this pathway.

The cells need a protein trigger to start this development. Just injecting these cells into a joint will not help in my opinion. So far, when this new cartilage in grown in the lab, it does not “stick’ to bone (at the tidemark) which is a major drawback.

In regards to the spine, the spine stiffens over time in everyone. This is due to the avascular and degenerative nature of the spine as well as the great loads. Stiffness is not a bad problem in many individuals in the lower back. I do agree that it would be better to have motion and this is why I endorse artificial disc replacements (ADR) in the cervical spine. I do not endorse ADRs in the lumbar spine due to the greater load and pathway to implant them (through the belly-see my discussion of them on the website).

There are some other possibilities which I am exploring.

If you love new knowledge, challenges and sleepless nights, you will love medical school and residency. I highly recommend it!

Dr. Corenman

PLEASE REMEMBER, THIS FORUM IS MEANT TO PROVIDE GENERAL INFORMATION ON SPINE ANATOMY, CONDITIONS AND TREATMENTS. TO GET AN ACCURATE DIAGNOSIS, YOU MUST VISIT A QUALIFIED PROFESSIONAL IN PERSON.
 
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.

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