Research For Clinical Trials

The foundation of The Spine Institute at RMSO  is research. At the core of that research is our extensive participation in numerous clinical trials for the scientific advancement of cervical and lumbar treatments.

Technology is changing rapidly, and while there are a number of devices in various stages of U.S. Food and Drug Administration (FDA) approval, there are also investigational devices that are gaining full FDA approval on a regular basis. The staff at The Spine Institute will help you understand the current standing of all devices and select the right procedure for your condition.

The Spine Institute at RMSO is now enrolling candidates for a variety of clinical research trials to examine alternatives to lumbar and cervical spine fusion, including lumbar and cervical artificial disc replacement, and treatments for lumbar stenosis. These trials are a part of an FDA application to gain approval for a number of devices and procedures. Some of these surgical procedures have been performed in Europe for over a decade and are now being subjected to scientific analysis in the United States. You may research all clinical trials at

The clinical trials are designed to prove the safety and efficacy of devices for treating degenerative disc disease (DDD) and other conditions that are currently surgically treated with a spinal fusion. Each trial has its own requirements. If you are interested in participating, please fill out the form at the bottom of this page or contact: Kira Sniff  Clinical Research Coordinator, (970)-669-8881 x 229


Previous Clinical Trials

Freedom™ v. ProDisc™ (Closed)

The AxioMed Spine Freedom Lumbar Disc artificial disc replacement trial compares the Freedom Lumbar Disc (FLD) to the FDA-approved artificial disc ProDisc™ L. Participants with a single level Degenerative Disc Disease from L3 to S1 will be randomly assigned the FLD or the ProDisc L.

The FLD is a one-piece total lumbar disc replacement device. A special plastic (silicone polycarbonate urethane polymer) is placed between two metal plates and a metal cap locks to each plate.

The FLD device has been used in England and Germany in 50 subjects in a clinical study. Researchers are still studying the long-term effects of the FLD in these subjects.

In the clinical study in the U.S., the FLD is being compared to the FDA-approved ProDisc L. Enrollment is closed at our site and participants are in long-term follow up. The artificial disc is still several years from being submitted to the FDA for approval.

Maverick™ (completed FDA study)

The first FDA investigational device experiment (IDE) study of The Spine Institute was a prospective randomized series comparing the Maverick™ lumbar total disc replacement (TDR) with anterior lumbar interbody fusion (ALIF). The principal investigator for the study was Dr. Kenneth A. Pettine.

This was a prospective randomized control trial under FDA guidance comparing the Maverick™ TDR with an LT cage and Infuse. This study was sponsored by Medtronic Corporation.

Degenerative disc disease is a common condition affecting millions of patients each year. The standard surgical treatment has been lumbar fusion. The introduction of lumbar disc replacement has given surgeons another option in treating discogenic back pain. The Maverick™ lumbar disc was the first TDR to prove superiority over fusion. The first study case was performed on April 28, 2003. Overall, 577 patients were enrolled into the study in 31 different United States sites.

The purpose of this study was to evaluate the clinical outcomes of Maverick™ TDR with ALIF at two-year follow-up. We are currently achieving five-year follow-up in over 78% of our patients. All surgeries were done at one level at either L4-5 or L5-S1. Success was defined as an improvement in 15 or more points in the oswestry disability index (ODI) with no revisions or device removal and no major device related adverse events. The patients were randomized 2-to-1 to receive a Maverick™ (25 patients) or an ALIF procedure (11 patients).

   Pre-Op ODI  1-year ODI  2-year ODI  Avg ODIImprov. Pre-Op VAS  1-year VAS  2-year VAS  Avg VAS Improv.
 Maverick™  56  15  15  74%  7  3  2  71%
 ALIF  58  35  41  29%  8  5  6  25%

The Maverick™ pre-op average ODI was 56. At one year, this had decreased to 15. At two years, it was also 15 for an average improvement in the patients of 74%. The ALIF pre-op ODI was 58 and their one-year ODI was 35 with their two-year ODI being 41, for an average improvement of 29%. The visual analog scale pre-operatively for the Maverick™ was 7. At one year, the VAS was 3 and at two years was a 2 for an average improvement of 71%. The ALIF pre-op VAS was 8. At one year, the VAS was a 5 with a VAS of 6 at two years, for an average improvement of 25%. Clinical success was achieved based on strict FDA criteria in 84% of the Maverick™ patients and 55% of the ALIF patients. These results had been maintained through five-year follow-up. Three of the 11 patients or 27% in the ALIF group required posterior fusion because of a pseudoarthrosis. Overall patient satisfaction was 95% for the Maverick™ TDR and 78% for the ALIF group.

In this study, 84% of the Maverick™ patients were considered a clinical success. Furthermore, 44% of the Maverick™ patients had an ODI score of less than 8 and VAS of less than 2, and they would be considered to have normal function without back pain. These results, along with data from other sites, prove the lumbar disc replacement is statistically superior to fusion and is a viable option for patients with discogenic back pain. The Maverick™ is currently awaiting final FDA approval and this study is currently closed, but we will continue to see patients for longer follow-up. Kenneth A. Pettine, M.D., does receive royalties from the Maverick™ disc as the inventor of the implant.


Kineflex™ v. Charite™ (completed FDA study)

This study compares the Kineflex-L™ lumbar artificial disc replacement with the Charité™ lumbar artificial disc replacement.

Kenneth A. Pettine, M.D., was the principal investigator for The Spine Institute FDA IDE study.

This was the first prospective randomized study performed in the world comparing two lumbar artificial disc replacements. The Charité™ artificial disc is a DePuy Johnson & Johnson product, which currently has FDA approval for use as an artificial disc in the lumbar spine. The Charité™ was the first lumbar artificial disc to get FDA approval. It consists of two metal endplates with a polyethylene insert. It has a unique design allowing coupled motion of flexion and translation. Of all the artificial discs, some engineers do feel it most emulates normal spine motion. It has been implanted in approximately 50,000 people outside the U.S. beginning in the early 90s and has a long track record of human patient implantation. The Kineflex is an experimental three-piece metal-on-metal design. It has a unique posterior center of rotation and keel fixation into the spine.

The first implanted Kineflex-L™ lumbar artificial disc in the United States was performed on June 6, 2005 by Dr. Kenneth A. Pettine. The study consisted of a prospective 1-to-1 randomization between the two discs. All artificial discs were performed at either L4-5 or L5-S1. There were 31 Charité™ and 35 Kineflex-L™ procedures performed at The Spine Institute during the course of the study. Overall, 458 patients were enrolled into this study at 21 different United States sites. The Spine Institute was the largest study site in the United States. We currently have more than three-year follow-up data on all of these patients and have presented this data at numerous national and international meetings. This study is currently closed with continued patient follow-up.

KINEFLEX-L™ 61.1 20.4 19.3 83.9 27.3 26.9 91%
CHARITE™ 63.8 27.3 20.5 85 31.4 33.8 84%

This study has been accepted for publication in the peer-reviewed SAS Journal.

Under FDA Investigation – Enrollment Complete

Kineflex-C™ Artificial Cervical Disc

The Kineflex-C is a metal-on-metal cervical disc replacement that uses a mobile bearing design, allowing translational movement defined by a specially designed retention ring. It has been used in clinical trials internationally since January 2003, and clinical trials began in the United States in 2005. Enrollment for the study is closed and subjects are in long-term follow up. The artificial disc is expected to be approved by the FDA at any time.