The physics of bodies in motion is a mystery as old as the observations of Galileo, the laws of Newton, and the theories of Einstein.

Kinematics, the science of motion in human bodies, is only now beginning to enter a golden age of invention and technology advancements that leaves behind a world of orthopedic procedures that weld and fuse the spine to relieve pain. We have entered the era of motion and motion preservation.

SpinalMotion of Mountain View, California, is a leader in this era and is pushing forward into this future of human motion with its Kineflex platform technology.

There are three important things to know about SpinalMotion and the Kineflex® technology. SpinalMotion:

• Is conducting one of the largest clinical trials ever in the U.S. to evaluate the safety and efficacy of lumbar and cervical discs
  
  
• Is conducting the first trial to compare two artificial discs to each other instead of randomizing to fusion surgery
  
  
• Has new designs on their way for a posterior disc, a shock absorption disc and a laterally placed lumbar disc

Anterior, Posterior, and Beyond

SpinalMotion’s successful track record outside the U.S. and the success of its regulatory and clinical team in guiding the lumbar and cervical discs through U.S. trial enrollment completion, demonstrates the company’s capacity to become the total solution for all disc arthroplasty. And it’s not just for anterior approaches anymore. The Kineflex platform offers multiple techniques beyond the anterior approach and includes design concepts that allow for approaches from the back and the side.

Early Success

While spinal arthroplasty is a fairly new procedure in the United States, artificial discs have been used internationally for many years. The Kineflex lumbar disc was invented in 2002 by Malan de Villiers, Ph.D., and has been implanted in more than 1,500 patients outside the United States. The first 2-year clinical results of 100 patients were reported in the 2007 Winter edition of the peer-reviewed SAS Journal.

Here are some comments from the authors of the study:

• Exact posterior position of the device within the disc space was achieved and maintained in 98% of patients and compares favorably with other implants
  
  
• For single-level disc replacements, the operative time and blood loss was comparable to other studies
  
  
• Postoperative hospital stay and return to work data compare favorably to other studies
  
  
• The improvement in the ODI scores was comparable to that found elsewhere

The study concluded: "Good short-term clinical results were achieved with the Kineflex disc in a heterogeneous patient group including a high number of patients with advanced disc degeneration, severe disc space narrowing, and previous fusion with lumbar flat-back deformity. Accurate placement of the prosthesis can be achieved in the sagittal and coronal planes."

And now, America gets its turn.

Groundbreaking Scientific Contribution

SpinalMotion is conducting the first ever U.S. lumbar disc clinical trial that compares the effectiveness of one artificial disc (its Kineflex) to another artificial disc, instead of the gold-standard spinal fusion procedure. This has the promise of making an immeasurable scientific contribution to the field of spinal motion preservation.

In addition, the company is also currently conducting a U.S. clinical trial for its Kineflex®|C cervical artificial disc. Both trials have successfully completed enrollment with the lumbar disc completed in November 2006 and the cervical disc in June 2007.

Kineflex Lumbar Clinical Trial

The investigational Kineflex lumbar disc uses a mobile bearing design, allowing translational movement within limits defined by a specially-designed retention ring. Kineflex features a metal-on-metal design of cobalt chrome to potentially minimize wear and improve longevity. The endplates come in three sizes to maximize coverage of the vertebral bodies, and incorporate endplate serrations and a locating fin for initial stability.

A recent article in Spine showed that a mobile-core artificial disc reduced facet loading by more than 50% when placed at or near the center of the disc space, while a fixed-core artificial disc increases facet loading when compared with an intact disc in axial rotation, even when placed in an ideal position. “This finite-element study suggests that there is a difference between mobile- and fixed-cores when it comes to facet loads,” said Dr. Geisler, a co-author on the study. “Additionally, our study predicted much less stress on a mobile core, which may increase its longevity, compared to a fixed core.”

Researchers in the Kineflex study are evaluating the artificial disc for the treatment of DDD. The physicians will be comparing the safety and effectiveness of the Kineflex artificial disc to the FDA-approved Charité artificial disc for the treatment of discogenic pain at one adjacent vertebral level (either L4/L5 or L5/S1).

The study is a multi-center, prospective, randomized, controlled clinical trial. There are 450 patients enrolled in the study at 25 medical centers. Patients are randomly placed into one of two groups: (1) treatment with the experimental artificial disc (the Kineflex) or (2) treatment with the FDA-approved artificial disc (the Charité).

Kineflex|C (Cervical) Clinical Trial

The Kineflex|C disc also uses a mobile bearing design, allowing translational movement within limits defined by a specially-designed retention ring. The device features a metal-on-metal design to potentially minimize wear and improve longevity. The endplates come in two sizes to maximize coverage of the vertebral bodies, and incorporate endplate serrations and a locating fin for initial stability. The cervical device has been implanted in more than 500 patients outside of the United States.

Researchers are evaluating the Kineflex|C artificial disc for the treatment of cervical DDD. The physicians will be comparing the safety and effectiveness of the Kineflex|C artificial disc for the treatment of discogenic pain at one cervical level (from C3 to C7) to anterior cervical discectomy and fusion surgery.

The study is a multi-center, prospective, randomized, controlled clinical trial. There are 325 patients participating in the study at 20 medical centers.

Patients are randomly placed into one of two groups: (1) treatment with the investigational artificial disc (the Kineflex|C) or (2) treatment with anterior fusion surgery.

A Simpler Technique

The Kineflex technology platform features one of the simpler techniques for surgeons and patients. The instrumentation has been designed to simplify finding the disc midline and to minimize distraction during insertion the complexity of the procedure. Several former Charité investigators participating in the Kineflex study are pleased with the system because it's quick and easy.

Flexible Approaches

Charles Gilbride, Senior Director of Marketing for SpinalMotion says that the Kineflex technology and how it is applied to their family of spinal discs is what defines SpinalMotion.

"Our company has a broad platform technology for total artificial discs. We have used our technology in cervical and lumbar arthroplasty, and we are developing our discs to be used in the lumbar spine via multiple approaches. For instance, we can implant from anterior, and will soon have lateral and posterior placement options. We've progressed beyond just looking at anterior cervical and lumbar studies," says Gilbride. "Surgeons want to know, what's next?"

What is next are posterior placed discs which offer some key advantages. "We can minimize the invasiveness of the surgery with a technique that is familiar to spine surgeons. There's decreased morbidity which is great for the patient," added Gilbride.

A Company in Motion

SpinalMotion and the Kineflex platform technology have already demonstrated their success internationally with its anterior approach, secured necessary funding for American trials, attracted a regulatory and clinical team that completed a successful artificial disc trial resulting in an FDA approved lumbar disc, and now has completed enrollment of two more artificial disc trials.

SpinalMotion is a company and a group of professionals in motion. Visit the web site so you don’t miss what’s next.