Me: On January 21, 1983, you used Dr. Cotrel's instrumentation to treat a 13-year-old boy with Freidrich's ataxia—a hereditary, degenerative disease that affects the spinal column. Would you please tell us about this inaugural surgery?

Prof. Dubousset: The patient was an adolescent with a thoracic curve, and I informed his family that we were going to try a new surgery with the intention of omitting plaster casting during the postoperative period. I also had, of course, notified the director of the hospital that we were going to perform a new procedure. The director asked me what the risks were. I explained to him, as I had the parents, that if anything went wrong the procedure would be terminated, as the classical Harrington surgery at the time, by simply keeping one hook on top and one on the bottom on the concave side, and that the child would undergo plaster casting postoperatively. Therefore, the risk was not increased in relation to classical surgery.

The director gave me his consent, and the procedure was performed with no difficulties. The patient was up on the third day without a plaster cast or corset.

Me: What did you learn from the early procedures you performed with Dr. Cotrel's instrumentation?

Prof. Dubousset: During the first cases, we used two rectilinear (i.e., straight line) rods placed in parallel with the hooks on the concavity of the outer and intermediate strategic vertebrae.

For the outer vertebrae, at the beginning we placed a simple concave hook in pedicular distraction on top and in laminar distraction on bottom. We then quickly placed a pediculotransverse clamp on the convex side to have a compression hold, because supporting only transverse was really too weak and led to an easy fracture of the same, a laminar hook on bottom under the laminae on the lower outer vertebra, and a pedicular open hook on the intermediate apical vertebra.

Dr. Yves Cotrel

For the first idiopathic case, I equipped each vertebra of the curve with one hook per vertebra placed in "staggered rows"—one on the concave side and one on the convex side. The result was very good but always with rectilinear rods. During a later case, we were dealing with a patient with kyphosis, so we had to arch the rod to be able to make it penetrate into the hook. When maneuvering it into place, we realized this arched rod mobilized the vertebrae during the movements of the rod.

It was then that we understood the full benefit of a pre-arching, at the same time as mobilization of the rod in the horizontal plane. That same day, thanks to a vertebral model Dr. Cotrel made using the plastic components used in plumbing to protect pipes, we replicated the movement of the vertebrae on a pre-arched rod by exerting the rotation movements of the same. Thus, we discovered the maneuver of rotating the principal rod, which was followed by the creation of new ancillary clamps and instruments for carrying out this rotation.

The movements of this pre-arched rod and the stresses that led to this maneuver of rotating the rod, in particular at the level of the upper concave pedicular hook, led us to adopt the pediculotransverse clamp for the two sides of the upper support vertebra. Dr. Cotrel and his technical collaborators then created a more sophisticated model to better visualize what took place during this maneuver, which restored, even though perioperatively, the sagittal plane in thoracic kyphosis and lumbar lordosis, for example, for a major double curve even if its flexibility was not perfect.

So this is how, from week to week, we tried the new implants and ancillary instruments we conceived during successive procedures and that were produced in record time, thanks to the efficiency, ingenuity and enthusiasm of the SOFAMOR technical teams of Berck Plage directed by Dr. Cotrel.

Me: What prompted you to share the newly developed instrumentation with your colleagues in the United States?

Prof. Dubousset: We had begun to hold regular meetings at Saint Vincent de Paul Hospital in Paris for updates and critical studies on the files of our patients. Little by little, with everyone's support and participation, we established the various steps and refined the technique and indications. As a result, new implants were created and others suppressed.

This joint work went on for a very long time. In 1987, when on sabbatical in the U.S. but passing through Paris, my friend Dr. Michel Guillaumat there asked me to help him with a difficult adult case. We ended up producing the anticipated assembly after many difficulties and, on the return airplane to the U.S., I designed the hook, offset in both directions, which appeared to be indispensable to me. I sent the "artistic" drawing immediately to Dr. Cotrel, who had it redrawn industrially and then produced by his engineers.

Betsy Garrett-Fitch, the
first U.S. patient treated
by Drs. Cotrel and
Leatherman

In 1984 and 1985, Dr. Ken Leatherman (at the time with Kosair Hospital in Louisville, KY, now president of the Kenton D. Leatherman Spine Center, also in Louisville) and Dr. John Hall (Children's Hospital Boston, Boston, MA), among others, came on several occasions to observe and understand the technique. The close relations of Dr. Cotrel with Dr. Leatherman, to whom he'd been speaking of the project for several years, prompted us to perform the first demonstration of the technique in the U.S. in Louisville in 1985, and then going from there to Boston to work on a memorable lumbar fusion case. And it was on this patient that we were able to clearly demonstrate in America that the rotation of the posterior lumbar convex rod brought about a quite obvious and convincing correction of the kyphosis by restoring the lordosis.

However, already Yves Cotrel, with his great sense of organization, had pushed so that our initially small, informal meetings at Saint Vincent de Paul took on a much more structured, international presence with the creation of Groupe International Cotrel Dubousset (GICD), which, with its annual meetings in Paris and throughout the world, made possible fruitful exchanges and progress for everyone. Case discussions overrode lectures; the event's interactive nature was further affirmed with the introduction of "brain tests," in which the diagrams of the position of the implants had to be placed by the participants depending on the different cases chosen. Case discussions are now part of almost every orthopedic conference. This is another way in which "CD" served as a precursor.

Me: As we approach the anniversaries of this important spinal system, would you please share with us your thoughts on the impact that CD® Instrumentation has had on the treatment of spinal deformities?

Prof. Dubousset: It is true that this meeting with Yves Cotrel in November 1982 was fruitful and exciting for a great many of us.

It made possible not only the perfecting of new instrumentation, whose success was revealed by the number of patients successfully operated on throughout the world, as well as by the growing number of copies of the material and the correction principles and strategies that are now found throughout the world. It also revealed the reality of three-dimensional correction approaches to spinal conditions to a good number of surgeons.

Finally, it must never be forgotten that this technique, by eliminating plaster cast immobilization of patients operated on for spinal deformities, was a major and fundamental advancement for adolescents. However, it was even more fundamental for adults because this technique made it possible to operate on adult patients and even the elderly, in whom the indications were previously limited by the insupportable stresses and sources of complications associated with postoperative plaster-cast immobilization.

Me: Professor Dubousset, thank you for giving us such an interesting "behind-the-scenes" look at the development process you and Dr. Cotrel went through to transform an original idea into a truly innovative new approach to spinal correction. Out of an earnest desire to improve the lives of young scoliosis patients has emerged an instrumentation system on which a variety of applications—such as the CD HORIZON® LEGACY™ System and the TSRH® Spinal System—are based, for the benefit of patients of all ages.

Please check back throughout the next several weeks as we upload new blog entries, many of which, in light of this year's celebration of the anniversaries of CD® Instrumentation and the TSRH® Spinal System, will be on topics related to these two technologies. If you have specific questions, please send them to me. And as always, I'll continue to look for more opportunities to share interesting information with you in the future.

And remember, early detection of scoliosis is essential. For more information on how to determine if you or someone you know has scoliosis, see our symptoms page on iScoliosis.com.

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