The Spinal Kinetics M6 artificial lumbar disc is designed to replicate the structure and performance of a healthy disc. Its innovative design incorporates an artificial nucleus to allow shock absorption and a woven fiber annulus for controlled motion in all directions.
These characteristics accurately replicate the healthy 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, and prevent or delay additional adjacent level degeneration. 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"
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.
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 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.
Careful evaluation by experienced surgeons is critical to insure that the correct implant options are chosen for each level based on many factors. Dr. Karsten Ritter-Lang has the experience and the implant options needed to make sure the best possible outcome is achieved.
M6 Testimonial
"I had Degenerative Disc Disorder in L4-L5 and L5-S1, due to an accident. I was only 28, with the lumber spine of someone twice my age. I was told my only treatment option was a two level fusion, which I did not want to have. After surgery, I no longer have the pain I had before. I am very glad that I had the surgery and I would do it again in a second."
Brooke, M6 Lumbar Disc Replacement L4-5 L5-S1
October 2009.
Disc replacement verses other surgical options Currently several options exist for treatment of disc related problems. Often early disc disease is treated with removal of all or part of the disc or adjacent bone structures. These treatments discectomy (removal of disc material) and laminectomy (removal of the bone) primarily are intended to relieve the symptoms but do not treat the underlying cause , the bad disc. In addition, discectomy and laminectomy can destabilize the level and lead to future complications and likely future surgeries. Another more invasive procedure, spinal fusion, welds the vertebra together preventing motion at that level. This creates stress on adjacent levels and almost always leads to additional surgeries.
Dr Ritter-Lang on Fusion vs. disc replacement.
Disc Replacement Superior to Fusion! A new, prospective, randomized, multi-center clinical trial, which looked at nearly 600 patients who received either Medtronic’s Maverick total disc replacement or an anterior lumbar interbody fusion (ALIF) using bone graft, has concluded that the artificial disc replacement (ADR) approach is superior to an ALIF.
The investigators found that patients with an ADR showed statistically better improvements than patients with fusions, as measured by the Oswestry Disability Index (ODI), SF-36 PCS, back pain and patient satisfaction scores at all postoperative follow-up points.
Matthew F. Gornet, M.D., was the principal investigator and he said of the study: "If we look at ODI success as a 15-point improvement, this is the first study to ever have any group of patients to have greater than 80% success. The Maverick [group] was able to do so at six months on. More importantly, statistically, superiority was concluded for the Maverick for 15-point improvement at 24 months compared to our fusion control [group]".
The ADR group also returned to work 21 days earlier, and 86% of the patients reported that they would undergo the procedure again vs. 73% for the fusion group. Ref; Maverick™ Total Disc Replacement versus Anterior Lumbar Interbody Fusion with the INFUSE® Bone Graft /LT-CAGE® Device: A Prospective, Randomized, Controlled, Multicenter IDE Trial
The Spine Journal, Volume 7, Issue 5, Supplement 1, September-October 2007, Page 1S
Matthew F. Gornet, J. Kenneth Burkus, Hallett H. Mathews, Randall F. Dryer and John Peloza
Total lumbar disc replacement in athletes: clinical results, return to sport and athletic performance! Thirty-nine athletic patients fulfilled the inclusion criteria for this study. These patients participated in a large variety of different types of sport. Significant and lasting pain-relief was attained following TDR with a mean follow-up of 26.3 months (range 9–50.7 months; FU rate 97.4%). Sporting activity was resumed within the first 3 months (38.5%) to 6 months (30.7%) with peak performance being reached after 5.2 months. Thirty-seven patients (94.9%) achieved resumption of sporting activity. Athletic performance improved significantly in 33 patients (84.6%). Minor subsidence was observed in 13 patients (30%) within the first 3 months with no further implant migration thereafter in 12 patients. Participation in all types of sport recorded in this study was accessible for a high rate of patients up to the level of professional athletes as well as those participating in extreme sports. Preoperative participation in sport proved to be a strong positive predictor for highly satisfactory postoperative outcome following TDR. In a selected group of patients, however, preoperative inability to participate in sporting activities did not impair postoperative physical activity.
Abstract of; European Spine Journal, Springer Berlin / Heidelberg, Volume 16, Number 7 / July, 2007, Friday, January 05, 2007
