30845 Suppl Giot.pdf - Giornale Italiano di Ortopedia e Traumatologia

of the “horizontal plane” demonstrating also the influence of time
and growth. This also helps us to understand the side effects of our
previous instrumentations (flat back, progressive imbalance, etc.)
The development of the CT scan and MRI gave a mandatory
access to this horizontal plane, and in addition a much better
view of the soft tissues especially for the spinal cord and other
nervous structures.
One simple example of the improvement obtained by the modern
technology is given by the study of the thoracic shape in spinal
deformities: in the past measurements were done by citometry
but of course CT scan with 3D reconstructions allowed to get
more precise data, surface, volume, relationship with vital organ
(trachea, bronchi, and matching shape volumes and biologic
measurements, vital capacity, MEV …).
In parallel the development of the vertebral traumatology push
the surgeons to study the fracture type always in 3D.
From these understanding new concepts of spinal instruments
and strategies for correction were developed as soon as 1983 by
Yves Cotrel and myself, with that we call the CD concepts. This
need first a rigourous analysis simultaneously AP and lateral,
to recognize limits of the structural, compensatory curves and
also the flexibility and mobility in 3D of the segments supposed
to be left free of fusion. This determine the precise levels of
multiple strategic points of anchorage of the instruments, hooks
or pedicular screws on the chosen strategic vertebrae, linked to
the 2 parallel bended rods associated to their axial rotation or in
situ bending as well as selective compression or distraction with
finally a minimum of 2 transverse linkage producing a very rigid
fixation in a “railway fashion”, continuing to day to be kept, used,
and improved in many ways all over the world as well for long or
short instrumentations.
This 3D concepts are of course universal for all orthopaedics at
any place, as for all the organs of the human body and it is curious
to realize how long it takes to have “open eyes” on this evidence
for spinal deformities.
The establishment of basic principles coming from 3D for treatment
brought a real improvement of the results all the more than
the multiple point of fixation of the correcting rods don’t necessitate
any post op casting or bracing.
From that time all over the world these principles were applied
with numerous variations and improvement in the technique, as
in the implants but the basis remained the same.
These comments for primary analysis, strategy, instrumentation,
apply as for deformities during child hood, adolescent or adult
age but of course even more for the elderly people of the aging
spine where the possibilities for compensation are less and less
good as the time goes by. So the decision for a surgical treatment
at any age but even more for olders, has to be taken only
in accordance with the internal medicine team, after a complete
vital function checking, in perfect acceptance with the anaesthesiologist
team and always measuring the advantages and the
inconvenients of such a decision.
It appears quickly when reviewing regularly the short term and
long term results that the best prognostic factor for the quality and
longevity of the results were linked to the quality of the 3D global
and local balance in the space of the Spinal organ, after surgery.
J. Dubousset
It is why this push me to try to improve preop. analysis, indications
and control of the results not only with regular simple
X-rays even AP and lateral but with 3D reconstruction thanks
to stereographic simultaneous AP and lateral X-Rays and computer
reconstruction in 3D with the finite elements technique
and derivates developed by the engineers of the Biomechanics
Lab ENSAM in Paris that we met at the beginning of the design
of the CD rods.It was the real continuing of that fruitful collaboration
It is why when Georges Charpak (Nobel Price of Physics,
1992), came to us in St. Vincent de Paul (1995) to experiment
his discovery of an X-rays numeric detector with very low dose
of radiation, and when we have proven on repetitive cases for
chest, pelvis, spine (often necessary to control pediatric orthopaedic
pathologies), that the reduction dose was effective, we
push him to develop with its company, a device able to scan the
total body simultaneously AP and Lateral in a standing or sitting
or crouched position, giving a very precise numeric image in a
functional posture. With this only one shot of reduced radiation
dose, (10 time less than regular X-rays) thanks to the work of the
biomechanical engineers it was possible to obtain a 3D surfacic
reconstruction of the entire skeleton (with almost 1000 times less
than for a 3D CT Scan reconstruction). In year 2000, the EOS
machine (Biospace company) appeared, as reliable as the 3D CT
reconstruction for the surface aspects of that skeleton with a multitude
of applications useful for all kinds of orthopaedic disorders,
located any part of the body, and particularly for the spinal organ,
considered from its cephalic vertebra to its pelvic vertebra, but
also the relationship of any skeletal segment to another one, and
precise measurement of the chain of balance of the patient mainly
static but possibly dynamic when coupling is done with external
envelop markers recording during motion.
It appears very useful to study and analyse the consequences in
the space of aging, where the major role on the posture related to
the Pelvic Vertebra became of primary evidence.
For the present, when maximum analysis was done using all
clinical, imaging, and technological possibilities, the treatment is
more and more sophisticated, using all technical more and more
powerful devices as well for correction, as for resection of the
spine, with neural monitoring more and more reliable, it appear
that the “end goal” is still to obtain a solid fusion, leaving as
much as possible intact levels to allow sufficient motion to compensate
a residual deformity, and achieve balance.
We must notice that the progress in the biology for the bony
fusion has made also real improvement but still adding a significant
cost to an already very expensive surgery, and in my mind
only reserved to very few difficult cases.
The experiences done to keep or restore motion on spinal surgical
diseases are still in progress. The disc prosthesis or dynamic
devices have very specific applications, still to be precisely
determined, and the danger is that the technology (favoured by
the industry of the spinal implants), invade the brain of the
orthopaedic surgeons to a point where they will forgot the true
analysis of the pathology before implantation of these modern
and attractive devices
This is again the same for the so called instrumentation with-
S183