|Interview with Dr. David McCord, from the US, about the PERFX-2™ System|
Dr. McCord, can we start this interview with a brief summary of your early days as a medical student and how you entered the world of spine surgery?
I attended medical school at Cornell University in New York City. It was an amazing experience intellectually, socially and culturally, that opened my eyes to the world and changed my perception of life forever. A great thing about studying at Cornell is that it is affiliated with Rockefeller University, the Sloan Kettering Cancer Hospital, the Hospital for Special Surgery, and of course New York Hospital. Being in one of the premiere cities in the world, and studying in the largest biomedical institution in the country was definitely a fulfilling experience!
I then furthered my training at Duke University and quickly focused on the field of spine surgery. I found, as I still find it today, that spine was the most exciting area in orthopedics because so much research still needs to be accomplished. Spine care remains today a huge medical and social issue, with improving but still unsatisfactory results. The good news is that there is light at the end of the tunnel, as we appear to be on the cusp of a technological revolution with the incremental introduction of motion sparing technologies. It is very exciting to be a part of such an impactful endeavor.
Did you have a “hero” or a “mentor” who guided you through the complicated world of Science? If you did, what is the most important lesson you learned from that person?
Two names immediately come to my mind, Dr. Arthur Steffee and Dr. Paul McAfee. Paul provided me with solid foundations as a spine surgeon. He taught me the science of spine surgery, but also the importance of listening to patients to better understand their pathologies and make educated decisions. Art Steffee, as we all know, revolutionized spine surgeries in the United States. I had the privilege of working with him as a young spine surgeon involved with Acromed. He candidly shared with me his good and not so good experiences, teaching me so much in the process. In addition his insights on the art of spine surgery were invaluable, and I can honestly tell you that years later, there is not one day that goes by where I do not think about his teachings. One of his most endearing qualities was his ability to find common sense solutions to some of the most complicated scientific challenges. There is a lot to be said for common sense.
You have collaborated with many orthopedics organizations, working on motion sharing since the early 90’s. What did you learn from those experiences that led you to participate in the development of the PERFX-2™?
You are right. I have been a member of NASS since the early 1990s and of the American College of Spine Surgery for a decade. On the industry side, as I said earlier, I worked closely with Acromed on new technologies before the Depuy acquisition. As I have always been involved on the product development side of our industry, just like my esteemed colleague Dr. Fuentes, it is clear to me that only the synergy between industry and surgeons can lead to true innovations positively impacting patients.
What led me to the motion preservation arena are really two initial ideas. The first one came from my friend and mentor Art Steffee who often mentioned one of his common sense principles, which is that “fusion will surely remove pain and restore stability, but will also destroy the adjacent level.” The second one is that I have always had an interest in architecture and if you just look around, there is not one bridge or one building in the United States that does not apply load sharing principles to provide better resistance. So, it was clear to me early on in my career that similar load sharing principles had to be applied to the development of spinal technologies to make them more resistant, avoid breakage and work in harmony with the anatomy instead of against it. My first work on load sharing technologies was focused on semi-rigid cages. I then moved to semi-rigid plating systems, and working with Eden Spine gave me the opportunity to go one step further, and participate in the development of a new Dynamic Stabilization system.
What are the key biomechanical attributes that you want to see in a Dynamic Stabilization system? Do you believe that Eden’s PERFX-2™ system possesses those attributes?
Ideally, what all surgeons want to have in their hands is a technology that relieves pain while restoring the physiologic motion of the functional spinal unit, and in the process fight adjacent disc disease. Of course, totally restoring the natural kinematics of the diseased spinal segment is not feasible at this point in time, nature still does a job that we cannot reproduce, but if we could at least restore alignment to maintain load transmission and preserve some level of motion rather than totally eliminate it, it would be a substantial improvement. This is what we have tried to achieve with Eden Spine, and I am confident that the PERFX-2™ system is a step in the right direction.
If you had to summarize to another surgeon the rationale behind the PERFX-2™, how would you describe it?
First, the rationale behind my personal interest in dynamic instrumentations is purely common sense. The only way to remove pain and simultaneously maintain some level of functionality in the spinal unit is through motion preservation technologies. Yes, a fusion will remove pain in the great majority of cases, but in doing so, we remove functionality and just like it was not ideal to fuse knees and hips decades ago, it is not ideal to fuse spinal segments today. We all know why.
Having said that, we have a tough road ahead of us to get to the ideal solution, spine research is a science in development, but it is exactly why it is so fascinating and intellectually rewarding to be a part of. What we have done with Eden Spine is to develop a clinically relevant technology that restores the stability of the diseased motion segment, attempts to reproduce anatomical stress distribution and to provide unconstrained motion within the neutral zone, and controlled motion outside of the neutral zone.
If you allow me, I also would like to add an important concept which is the center of rotation. As you may know, it moves constantly and is even different for different age groups. To solve this issue, Eden’s engineering team has developed a proprietary dual spring mechanism designed to allow controlled motion in all planes, as well as provide some level of translation to allow the system to automatically find the center of rotation no matter where it is, no matter how old the patient is. This is a true innovation that has the potential to substantially improve patient care.
In your experience, what would be the ideal candidate for a Dynamic Stabilization implant and more specifically for the PERFX-2™?
For a single level posterior dynamic stabilization surgery, I would look for a patient with early disc degeneration with the disc at least 50% intact, limited or no facet degeneration and a healthy disc above.
I also consider that patients with a fused segment but a slightly degenerated adjacent level are candidates for a dynamically instrumented transitional zone in order to control the range of motion of the hypersollicated adjacent level. It will protect its longevity and potentially avoid adjacent disc disease. As we all know, 35% of fusion surgeries create adjacent disc disease.
You have been a pioneer in the world of spine surgeries since the early 90’s. Based on your experience, how would you compare the PERFX-2™ to other Dynamic systems?
It would be too long to do a comparative analysis, but I can tell you that I consider that the PERFX-2™ is truly a new generation posterior dynamic stabilization system. Eden’s R&D team has unparalleled experience in developing motion sparing technologies, and having experienced firsthand their global vision and understanding of the evolution of spinal technologies, I am confident that with the support of the surgeon team, they are advancing the art and science of spine surgery.
Looking back over your very long and distinguished career, which particular things in spine would you say gave you the greatest satisfaction?
The opportunity to interact with so many colleagues, as we pushed our field forward, always striving to improve the daily lives of our patients.
Thank you very much!
Orthopedic Surgeon, and co-developer of the PERFX-2 ™
David H. McCord, MD, is a board certified orthopedic surgeon from the United States, with outstanding expertise in the treatment of complex spine pathologies. A graduate of Vanderbilt University in Tennessee, Dr. McCord received his medical degree from Cornell University in New York. He then completed an internship and surgery residency at Duke University Medical Center. Dr. McCord practices spine surgery in Nashville, Tennessee. He has been in private practice since 1991 and is licensed in 4 states: Tennessee, North Carolina, Kentucky and Georgia. He has also been actively involved with numerous professional organizations including, among others, the American Academy of Orthopedic Surgeons; the North American Spine Society; the American College of Spine Surgery; and the American Medical Association. In addition, he has participated in numerous research projects, has given over one hundred presentations at major medical meetings and institutes worldwide, and many of his articles appear in peer reviewed publications.