The Spinal Kinetics M6 Disc Replacement
Unlike early Disc Replacement designs, the M6 artificial disc is designed to replicate the structure and performance of a natural disc. Its innovative design incorporates an artificial nucleus to allow shock absorption and a woven fiber annulus for graded variable motion resistance in all directions.
These characteristics accurately replicate the natural disc, allowing the implant to work in concert with the remaining human discs. Unlike earlier "ball-in-socket" implants, with M6 the resulting natural functionality of the entire spinal curve should provide the best chance for a full recovery. In addition, future complications should be eliminated by preventing adjacent level degeneration and strain on the muscles and ligaments.
This "Quality of Motion" is a major benefit not available in any other implant we have seen!
Studies show, "The kinematic signatures of the intact human disc and the M6 artificial disc are nearly identical"
"There has been no serious device-related adverse events, surgical re-interventions, or evidence of device migration, expulsion, or subsidence in this study group"
Dr. Ritter-Lang has been using the M6 implant for several years and has seen excellent results and reduced complications. These complication risks include adjacent disc degeneration and facet joint damage found in early "ball in socket" designs, and M6 has not been found to cause the ossification, found in other early generation compressible implants.
The Spinal Kinetics M6 has received CE Mark (European FDA) approval for use in the European Economic Area countries. The CE marking certifies that a product has met EU consumer safety, health or environmental requirements.
The Spinal Kinetics M6 has not been approved for use in the US and no trials are underway at this time.
Watch a video on "The evolution of Disc Replacement"
Disc Replacement Options and "Quality of Motion"
Disc replacement implants fall into two distinct categories, compressible, and non-compressible.
Non compressible devices include Fixed Center of Rotation; ball-and-socket designs, and Mobile Center of Rotation; mobile core and ball and trough designs.
Watch a video on "The M6 Design and Motion"
Aside from the obvious lack of shock absorption, non-compressible implants have several distinct characteristics.
A healthy disc provides a graded resistance to motion. Although, these non-compressible disc replacement implants retain motion, unlike fusion, the motion is uncontrolled. Adding load can make the motion characteristics even more unpredictable. The result can be motion which is not intended in the design or is sporadic. This is also referred to as stick-slip-friction. Because of this, facet joints may be overloaded, muscles are required to work harder, and adjacent level damage can occur. On the other hand, in a case where additional stability is desired, due to advanced disease or other factors, an implant with a fixed center of rotation, may be desired.
Compressible implants have the obvious benefit of shock absorption protection, but can also provide the required graded variable resistance to motion like a healthy disc. One of the first implants to achieve this was the Bryan cervical disc. Although this implant provided graded resistance, calcification was reported in as much as 12% of the cases studied. This issue has been resolved in more advanced implants like the M6 Disc. By provided the graded variable resistance, replicating a healthy disc, the M6 reduces facet and adjacent level complications. This "quality of motion" under load not only maintains a physiologically correct motion dynamic, it also is not as sensitive to placement variables as the earlier implants.
Watch a video on "The M6 Procedure"
Lifespan of the Spinal Kinetics M6 Disc Replacement
The M6 disc replacement was subjected to rigorous testing which confirms the
inherent robustness of the device. The disc remains fully intact
and functional after functional kinematic testing to 20 Million cycles of
combined motion; physiologic dynamic compression, compression
shear, and torsion; creep to the equivalent of 80-100 years; and worst
case physiologic extension over 30,000 cycles. Even when highly
nonphysiologic static loads are applied, the device does not
exhibit any mechanical or functional failures.
Careful evaluation by experienced surgeons is critical to insure that the correct implant options are chosen for each level based on many factors. Dr. Ritter-Lang and his team have the experience and the implant options needed to make sure the best possible outcome is achieved.