First True Total Spine Motion Segment

[mmglobal]

On Sunday, Diane and I had the pleasure of a visit from Dr. Bertagnoli. As usual, we got to discussing difficult cases and new techologies. One of the promising developments is the Total Spine Motion Segment by Disc Motion Technologies.

Dr. Bertagnoli has now done several cases and he's very pleased with the way things are going. This technology offers new options to people who have spinal stenosis in addition to DDD, including those with severe facet arthropathy. The all-posterior surgery in conjunction with the posterior stabilization that is used along with the total disc replacement, allows the surgeon to do a substantial posterior decompression along with the ADR.... something that cannot be done with the current crop of anterior total disc replacement solutions.

I wrote about this technology in October 2007 on my NASS blog... here it what I said at that time:

Originally Posted by mmglobal

First True Total Spine Motion Segment System (#5 10/26/07 0:30 from Mark's blog)

Thursday afternoon, I saw some new technology that really piqued my interest. Disc Motion Technologies has developed a new system that solves many problems that limit options for some patients. Many of us have facets that are too severely degenerated to allow total disc replacement. This new system is composed of 2 disc replacements implants that can be implanted through a standard PLIF (posterior lumbar interbody fusion) approach, plus a total facet replacement. The disc portions are like an current artificial disc, but cut in half. This allows one segment to be inserted through each side, eliminating the need for a larger access path currently requred for ADR implantation. The problem with the other PLIF total disc styles is that they require removal of so much of the posterior column; required stabilizing structures are removed. The Disc Motion Tecnologies solution includes a facet replacement system that is designed to complement the kinematics of the total disc in front. It will be interesting to see how this all unfolds: will this only be for patiets with compromised facets? The system was developed in the UK and we won't see human implantations until next year... so this is many years away from general availability. I was glad to discover that technology after you discover it, the solution seems so obvious... why didn't we think of that before?

In pictures below (from the disc motion website - international products), you'll see the pedicle screw system and the dynamic coupler that controls motion and stabilizes the system, while the total disc has been split into two half discs, so they can be put in separately through a posterior approach.




I'll keep you posted as I hear more...

All the best,

Mark

[Maria]

Great topic and can't wait to hear/read more!

[johnb]

Very promising indeed. Will be interesting to see how it plays out. I wonder about long term screw anchorage into the sacrum. I'm assuming any revisions would be done posteriorly which poses risks to neural structures but spares manipulating the great vessels of the anterior. Keep us in the loop Mark. Dynesys smynesys.

John

[Maria]

What would be the exclusions spinally for this type of system?

[mmglobal]

I wish I would have seen this earlier... I dropped Bertagnoli off at the airport and could have asked him. Not knowing the answer, I'll be happy to make one up... (actually I don't do that... I'll post my thoughts... could be wrong, take it for what it's worth.)

Per my discussion with Bertagnoli, posterior elements are NOT replaced by this system. I believe that this system is much more tolerant of issues in the posterior elements than anterior ADR because, being a posterior surgery and adding a stabilization system, they have great license to do more decompression and deal with issues that cannot be addressed via anterior ADR surgery. However, the system still needs to have stability. My understanding is that this is not for people with significant spondy conditions. Degenerative spondy (instability related to collapsing disc spaces and the "detensioning" that goes along with it) is OK, as it is with ADR. Isthmic spondy (from true structural deficiencies like pars defect) will not be addressed... we'll need a more comprenensive replacement for the posterior elements for that.

Again... this is new... I can be wrong... I'll let you know what I hear. I'm just sharing something I think you'll find interesting.

Mark

[martyusa]

From what I can gather it would be a combination of a pedicle screw and Rod device in combination with a Maverick type ADR without the actual fusion of any bone material.

So we would get the benefits of the fusion support with the rod and screw system as well as the mobility from the ADR with easy access for adjustments/revisions if needed in the future.

Let me dig up some more info and post more detail on the product and the company.

[johnb]

Disc Motion Technologies

In the top picture for the The True TSMS™ , I don't see any posterior elements.

John

[mmglobal]

I wouldn't call it a maverick type ADR. The Maverick is very tall with a VERY small radius ball and socket that gives very different motion than this split system would yield with it's larger radius mating surfaces.

I keep looking at the picture and go back and forth between believing that the facets are gone... then I look some more and I think they are just obscured in the drawing.

It will be interesting to learn more.

All the best,

Mark

[martyusa]

I was referring to the material. Cobalt Chrome or a metal on metal type ADR. Didn't mean to confuse anyone, I should have been more specific.

[Tim]

Hi all
I've just had the TSMS recommended to me by an eminent European surgeon well known to this board. The idea would be to place this system at L4/5 between my 2 existing Charite ADR's at 5/S1 and 3/4.

Does anyone have any more news on this system and has anyone here had it done or do you know of anyone who has had it done..

To me it looks promising but scary because it's new and dare I say it experimental. I've so many questions and the literature doesn't seem to be there at least not for public consumption. I assume the facets are left in place but if so how are they unloaded? Will the pedicle screw system suffer from failure and if so how easy will it be to revise? Is it all metal on metal? Is it a keeled design? Is the approach purely dorsal - if so the prosthesis endplates must have a pretty small footprint and may then be more liable to subsidence.. I could go on and on......

Thanks in advance for any input
Tim

[fortitudine]

Is this a lumbar system only?