. : Grenoble-native summers you?

TOKEN ENTRY: I am Grenoble-native and, to be precise, I was born with the Mug, the private clinic of the Alps. I will not tell you that very early I wanted to make medicine because it was not what tried me more. On the other hand, I liked biology. I finally directed myself towards medicine in final class. I made all my medical studies in Grenoble while starting with famous 1968. At the end of a fast formation, I told myself that after all I could not make me with the and without having very precise idea, I thought that the solution it was the boarding school, in order to have a speciality and to go at the content of the things. I made a success of the boarding school in Grenoble and Tours. I was placed better at Tours but I could not pass to me from the mountains and the ski. My boarding school began in Grenoble in 1977 in neurosurgery. As of second half of the year, I discover csotcina.comedy and Jean entrusts from the start to me a mission. He tells me here are “” one goes with the ; I have 40 files of total , after fracture or osteoarthritis; you re-examine the files, and you make a scientific panel. I hung immediately and in all I remained three six-month periods (but not the sharp one), in his service. I also made a six-month period of traumatology in the service of Henri for nths. One learned how to me to make an osteosynthesis by plate in the code of practice (not to put the fingers everywhere, not to mix the bones with the forceps, not to push on a square point in a ill-considered way, to make a success of a maneuvre of removes tire etc…). Mr had been trained at Maurice and Mr was the pupil of Mr
.

. : There was an opposition between them?

TOKEN ENTRY: Yes, because I believe that there was of it an owner who was deeply csotcina.comedist and who the other owner was primarily . Henri was a general surgeon come to traumatology and it practiced it extremely well. Jean was the csotcina.comedist of Grenoble and its formation came mainly from the School.

 

. : It is which you assert as Master?

TOKEN ENTRY: Yes it was my owner, and my Master and it is it always. I am very proud. It was very user-friendly. When one was his friend, that was not surface. It started to want to undoubtedly call me his son because one had a community of thought (community medical, scientific, ethical, philosophical…). It had great human qualities and it preserves them always besides.

 

. : Was to have much other pupils, then why to have chosen to you?

TOKEN ENTRY: It is difficult to tell. I in any case think that there was something which it appreciated, it is that I was very often with the block to help it, and I, so profited from something from incomparable: the experiment. I helped my owner for all the resumptions of hip. I am often dismayed when a young Chief gives me consultings in connection with the resumptions of hip! …

 

. : Didn't the others help it?

TOKEN ENTRY: One moment ago when it is necessary to play of the elbows and I arranged myself to be the first on the intricate businesses. I stuck with him because in more when one operated one often joked. There was a true complicity between us.

 

. : How was born the hip prosthese from ?

TOKEN ENTRY: Jean was influenced by the technique of the nail fascicle, i.e. central-medullary nail for femur and tibia, was fitted with four strands, joined together at the two ends of the nail and which dates from the beginning of the year 1970 - and that one still puts in the service. I remember that at the end of the Seventies the first prostheses without cement of the service (manufactured by society Science and Médecine-) had a diaphyseal stem full, broad, and of rectangular section. Jean told himself starting from this drawing one could consider a stem with four strands. It is SEM which manufactured this prosthesis to him which was to some extent a hybrid system between the conventional SEM without cement that much among us knew and the nail fascicle.

 

. : Which were its other poles of interest?

TOKEN ENTRY: All the large hinges and the axial skeleton interested it, but one especially worked on the hip. It was impassioned by that but also by the osseous consolidation. Its anguish was to have pseudarthroses. For that he told me that he did not want method of Wagner of limb lengthening in his service. Thus, when I exposed to him the principles of the method of , he told me “here is an intelligent type”. One went to the first meeting in , to Italy with the beginning of the year 1984, the invitation of , and it is there that we discovered the method but also the character of .

 

. : What becomes Grenoble-native csotcina.comedy?

TOKEN ENTRY: Dominique was appointed in 1990, and me in 1991. Dominique left to the Southern Hospital. He took again the service of which was a department of traumatology and he made it evolve to sports traumatology. He did many knees, he always does much of it. We, we remained at the Northern Hospital. The department of pediatric csotcina.comaedics always exists, but gathered with the infantile department of surgery. Like everyone, we had to decrease our number of beds. In the pediatric department of csotcina.comedic surgery, there are 15 beds. In the adult department of csotcina.comaedics that I direct there are 70 beds divided into 40 beds of greeting of traumatology and 30 beds of pure csotcina.comedy. Thus there are two distinct unities; one of cold csotcina.comedy and a unity of greeting for the urgencies.

 

. : How did you come to the surgery computer-assisted?

TOKEN ENTRY: By chance, there is a little more than 10 years. One had, and one has always fortunately, an engineer of great quality, a doctor data processing specialist who is called Philippe . He is instructor at the medical college of Grenoble. He called to me, 10 years ago one Saturday morning to tell me: “I have a brilliant trick which one developed and which makes it possible to make navigation in the vertebrae, while basing itself only on the virtual imagery”. I went in his office and it showed me on a screen of computer, a model of vertebra in 3D reconstituted starting from a scanner. There was a plastic vertebra which was on a table. He told me, you see there are tools, the cameras are with the top of you and with this pen you will seize points. I took points on the posterior arch of the vertebra and he told me that these points were going to be amalgamated with those of the vertebra, which the computer did very easily, in 5 seconds. After it was put in mode navigation and asked me to try to descend a tool in the boreholes in the pedicles. I descended my tool and one followed that real-time, it was rather extraordinary. I told him that its system probably much future and that had to be begun immediately the clinical studies had. But we have whole to develop: precision of the system, to carry out tests on corpses… etc… The tools were tools of plastic laboratory which could not support sterilization with 130°. it was necessary to find and design new tools, to test them with heat and to make their handling user-friendly. One made the first surgical gesture of assistance for the sighting of the vertebral pedicle on May 10th, 1995. It will have taken us four years for all to test (all instruments and all systems) and all to validate.

 

. : From which did you leave this engineer however advances some for the time?

TOKEN ENTRY: It was formed in Dijon where it made its medicine. But before the weather was polytechnic and it thus had a very thorough scientific formation. It came to Grenoble called by another data processing specialist from the hospital which had followed the same course. They invested in the medical informatics, in the broad sense term, and understood very early the importance and the possibilities offered by the revolution of the numerical whole in the field of the medical imaging. Once digitized, the medical image can undergo various transformations: it can be used to modelize parts, it is easily transferable (cassette DAT, optical disk, , cable, WEB), and especially, these of the same images source or of different sources, can be amalgamated in order to be able to guide in an active or passive way surgical tools. The engineers implemented the basic principles of robotics here.

 

. : They thought from the start of making navigation?

TOKEN ENTRY: Not, the starting idea was to create tools for simulation for the surgeons: to simulate the rebuilding of the face, for example. It is only after they were told that they could make navigation. All that started within laboratory (Technique of the Imagery, Modeling and, of Cognition). This laboratory belongs to the (Institute of Mathematics Implemented of Grenoble). The unit is affiliated at CNRS and, belonged to the University Joseph Fourier. A considerable party of the work of design and realization was carried out by two “key engineers” Stephan and, . directs the laboratory and it has under its commands 10 or 12 PhD students permanently. Its laboratory is a laboratory of robotics. Navigation was born from the capacity which the images thanks to the computer had the engineers to amalgamate and to implement the principles of robotics. They were told that from the moment or one has a preoperative image of a part X, as from the moment or one can identify remarkable points on this part X, as from the moment or one can find these same points on part X in , one can amalgamate the preoperative digital image with the numerical informations . When the merger is carried out one can find the optimal strategy of the positioning of an implant, for example. In other words one amalgamates the real-world (the operative field), with the virtual world (the preoperative numerical image) and one thus actually works “virtual”, or “increased better, actually”. I remember a meeting in Grenoble with representatives of the department of health and ministry for industry in 1991. One all was joined together in a room of the and one decided to launch the first clinical application. The selected implementation was the rachis, with the assisted sighting of the vertebral pedicle.

 

. : At the beginning, which financed them these search?

TOKEN ENTRY: We were given a financing of the type (Hospital Project of Clinical research; Department of health) and of a considerable aid of the INSERM, to start. The following year, 1992, we received an aid of Brussels, via European research program (Image ).

 

. : Why did they call upon you?

TOKEN ENTRY: On a side, the clinical teams existed and ours in particular had made an significant effort towards the engineerings (POSTGRADUATE DIPLOMA; Theses of University). Other side there were a fantastic unexploited scientific potential and a will to better know sciences of the alive one. The senior of faculty, Jacques , at the time, called me a few weeks after made me its proposals by telling me that it was essential to exploit this die, for strategic reasons: “if you do not go there it is the catastrophe”. Finally was born an agreement which functioned thoroughly between the researchers and the team of csotcina.comedy, because the men appreciated themselves and adhered to themselves.

 

. : How that does it occur at the time from the implementations?

TOKEN ENTRY: In fact, at the beginning, we were with the capture with a system terribly difficult to manage. One needed an engineer, and two computers; into preoperative, it was necessary to segment the images manually… it was intricate because one worked with a prototype of laboratory. It is as from 1996 that enters in scene which had already its system of retiming containing points but which did not have the technology of the “scatter plot” for this same retiming. An agreement was thus signed between the following actors: the chairman of the university Joseph Fourier, the staff of and laboratory , and it was yielded to the exploitation of the patent on the “scatter plot”, with all the consequences which you can imagine as regards royalties for the university…

 

. : And you had the means of expressing you?

TOKEN ENTRY: Yes, absolutely since the means as men, hardware and financial means were granted to me: we could have 250 a year to F.

 

. : Is the development of this kind of program expensive?

TOKEN ENTRY: In fact, the development of this kind of program appears much more expensive in term of time spent than in term of financial means. On the other hand, if one included in the overall costs the hourly salary in term of spent time, then he is true that this type of search is very expensive.

 

. : I suppose that you have this time powerful aircraft?

TOKEN ENTRY: After an essential phase of grubbing with the prototype of the laboratory, the true adventure of surgical navigation started with Station which I had seen in at the beginning of 1996. It was a marketable aircraft and which forwarded information in user-friendly form. We had all on the screen: the face, profile, axial sight and the sight 3D. The technique of the “scatter plot” having been integrated, a few months later, one started to work on pedicular screwing in April 1996.

 

. : What the technique of the scatter plot, and how is made the identification?

TOKEN ENTRY: The digital image of a modelized vertebra still called virtual image, starting from an examination can be comparable with a great whole of points (or pixels). Of per-operational, i.e. in the real-world, the operation consists in taking in a random way a certain number of points on the surface of the posterior arch of the operated vertebra; the same one as that which into preoperative, of course. Forty to sixty points are usually necessary and sufficient. The identification of the points is done using a three-dimensional optical locator fitted with infra-red cameras. These cameras permanently record the position of the tools of the operative field because each tool is equipped with electroluminescent diodes which issue a sequential signal. To be validated, this identification must be made in the “patient” reference mark; One should not lose sight of the fact that a navigation can be undertaken only starting from one stable reference frame and perfectly identified. Lastly, let us say that the optical locator acts like a system of localization of the GPS type. Using an application software the work of the computer consists in readjusting the points acquired in patient, or real” on the points of model or virtual reference mark the “. This phase of merger or “mapping” is crucial, because it is it which validates or not the precision of navigation. A few seconds are necessary so that the computer carries out this work. It is the technique of merger of images containing the scatter plot (“surface registration” of the Anglo-Saxon authors) which gave rise to the first clinical experimentation in 1995.

 

. : Were you a surgeon of the rachis before “navigation”?

TOKEN ENTRY: Not really; I became it. Previously I had small customers of degenerative rachis, then I inherited, with the of service, of the scolioses and part of traumatology, by the force of the things. It is with these pathologies which one could show that Station could give further information for the pedicular sighting. The screws exactly are put or it is necessary, which makes it possible to avoid the false routes on dystrophic pedicles and in more one has a capture which is fantastic.

 

. : Does one need a preoperative numerical acquisition of the patients?

TOKEN ENTRY: Yes because as regards scoliosis each case is an typical example and the consequences of a false route can be major. That posed problems in term of investment:

- need for having a scanner equipped with a system of spiral acquisition.

- conservation of the examinations on optical disk.

- amendment of the systems of imagery to standard DICOM 3 (DIGITAL Communication in Medicine).

- data-processing rebuilding in 3D.

All that is enough time consuming but less as regards financial means. The precision, comfort, and the security which a navigation system at basis as regards scoliosis gets is incomparable. On the other hand, for the knee for example, one will leave gradually towards another revolution which is the statistical bases of anatomical data.

 

. : Database anatomical?

TOKEN ENTRY: Yes, and it is another adventure. One takes nees of healthy subjects then one makes 40 scanners of these knees and one has a statistical basis of anatomical data. The work and the merit of are to have developed a software elastic strain. This software makes it possible to readjust the numerical data condyles (acquired using a tool fitted with diodes) of the knee of Mr Dupont on the statistical model which will approach some more. One can obviously proceed in the same way in all the anatomical areas (shoulder, elbow, hip, foot, rachis, mining area) on the condition of having sufficiently elaborate statistical models. Under these conditions, one does not have more need for specific imagery preoperative (To scan) and one goes to the block with the conventional imagery of diagnosis. With the , only the computer and a three-dimensional optical locator are essential and the first clinical trials implemented to the installation of the total prostheses of the knee must begin with the autumn 2001. But that, one cannot do it with a scoliosis which is highly specific to an individual and other ways of research exist. Their aims consist in abolishing the preoperative numerical acquisition of type , to replace it by an equivalent imagery, obtained starting from an image intensifier of new generation likely to provide directly to the operator images 3D MID European project 3.

 

. : Which are the economic implications?

TOKEN ENTRY: The systems which one spoke since the beginning about the adventure about the rachis function all with operating systems sophisticated (on UNIX basis) and these operating systems data processing are rather expensive (1.5 to 2.F). One will attend with a reduction in the costs by the use of the Windows platforms and the use of workstations , as we conceived in Grenoble: the naked station costs approximately 380 003 francs, and for this same station he is proposed with the various specialities the modules of implementation which interest them: rachis, knee, hip, mining area, shoulder etc… but also ENT SPECIALIST for the surgery ; radiotherapy for the irradiation of certain tumors etc… a module of implementation should cost approximately 440 068 francs.

 

. : For do your scolioses you make use of that now?

TOKEN ENTRY: Not. But starting is provided for during 2002 (while always remaining on a basis ).

 

. : It there forever of false route in spite of ?

TOKEN ENTRY: Yes of course! I will tell you an anecdote. We had the inspection of neurosurgeons of Besancon one year ago. They arrived one day when a scoliosis was programmed. One of the screws did not hold very well. I had already posed of them three with the machine and they held perfectly well, but the fourth did not go. I took again the way in the pedicle only with my scraper (thus without machine). I replaced my live with the hand and there, I could note that it held very well. At this point in time one of my visitors stated, not without humor, “that is finally very reassuring!”. One makes sometimes aberrant intra-pedicular ways as regards scoliosis and it is enough to look at the postoperative cuts scanners to convince itself some. There are pedicles on the side of convexity which are very broad, very spongy and one passes through very easily and then side of the dishing they are often very dense very sclerous and one cannot easily “put at side”. For this reason, I think that the screwing of the pedicle must be assisted, as well as drilling.

 

. : Which are your results?

TOKEN ENTRY: We have an exemplary collaboration with the service of Gerard Covering in Pitié Salpêtrière. This collaboration was initialized by Jean Pierre now three years ago. One was to make on each site 50 drawn patients with the fate (with or without assistance). With the end of the year 2001 the study will be finished. For the moment only the Grenoble-native data relating to of the former studies were published: we have between 25 and 40% of the screws which are not place from there, i.e. out of the pedicle, with the manual techniques, and less than 6% with the system of assistance. The 6% of screws not strictly intra-pedicular are explained by errors of retiming related to a bad technique of acquisition of the points in the course of intervention. This phase is completely “surgeon dependant” and the computer is not in question.

 

. : it have a clinical repercussion?

TOKEN ENTRY: For the screws which were not places from there with the conventional technique, we observed two cases of which yielded after surgical recovery. With the machine, there was a recent incident in the form of a syndrome of the very transitory cauda equina and which completely regressed in three weeks. We did not understand why (causes vascular?), and postoperative of the positioning of the screws controls it was perfect.

 

. : What will that imply on the medico-legal level?

TOKEN ENTRY: I think, that one will end up asking to people who make rachis if they had a navigation system at the time of their act as well as a hardware for the referred to potentials. When one reads the current reports of expertise it is noted that the loss of chance and the insufficiency of means are almost always stressed.

 

. : Was navigation implemented to the hip?

TOKEN ENTRY: Not, because that was not our center of initial interest. On the other hand surgical navigation on the level of the hip was and remains the main concern of certain teams, like that of Anthony to or that of in Bern. To position a prosthetic with a system of assistance does not appear fundamental to me because the anatomic specimen is under the eyes. The large future favors navigation systems active or passive for the hip surgery will be at the level of the recoveries with in particular the very difficult problem involved in the ablation of cement in the femoral diaphysis. For me the assisted surgery has two centers of major interests: firstly, the assisted surgery is used to visualize parts or segments of nonvisible parts in the operative field; secondly the assisted surgery is used to optimize a usually difficult gesture (positioning of the implants of the prostheses of the knee; positioning of the tunnels for the Clerc's Offices of cruciates in order to improve the concept of ). There remains still another clinical and technical challenge: the modeling of the balances and muscular…

 

. : Do you think that there are indications in traumatology?

TOKEN ENTRY: Of course and of multiples which will make it possible to decrease the use of the conventional fluoroscopy. I think that one of the best implementations is represented by the locking of the central-medullary nails. At the time of last congress of csotcina.comedy of Fort de France in the month of March 2001, there was an interesting discussion, almost polemical, between , T. and myself, about the use of the virtual fluoroscopy. pled for the virtual fluoroscopy while arguing on the fact that one decreases by practically by 50% the exposure time to the X-rays. I confirmed this data because a system of virtual is installed in Grenoble since August 1999. Thierry simply pointed out that the Strasbourgeoise school had often minimized the importance of the amounts delivered during the installation and of the locking of the central-medullary nails. For T. , one must even be able to carry out an osteosynthesis without image intensifier. To meditate…

 

. : Which is the difference between the systems liabilities and assets?

TOKEN ENTRY: The passive systems have much future. A passive system makes it possible to carry out a navigation in conformity with a preestablished trajectory (without it being an obliged stage) but constantly the surgeon keeps the control of the gesture and can stop or decide not to more follow the data which are forwarded to him. With an active system, one determines an optimal strategy starting from a preoperative imagery. For example, I want to remove cement inside a femoral diaphysis: thanks to the computer, I draw contours of cement and I digitize information collected which are transmitted to a machine tool, i.e. the robot. After this stage, the machine does the work for which it was programmed only and without aid. The disadvantage is that one needs a preliminary operative intervention for set up of the reference marks on the patient. Side of the active systems, I do not see great future for the “monsters” which are the current robots. I on the other hand see a future for the microcomputer-robots. There is an European project which finishes, and which is called (Compact Robot Image ). It is a robot which is not larger than a coffee machine. It can be transported easily and it is installed on a , which makes it directional in all the directions. It was developed thanks to a collaboration between in Grenoble and the Helmholtz institute in Aachen.

But it there another thing; semi-active systems: in fact systems make it possible to navigate in a space that you have predefined. In other words, it will prohibit to you to go there or you avoided going. There is a machine which is very advances some for that and which is in experimentation at laboratory in Grenoble: it is the system “” which is presented in the form of an arm to dynamic stress. This dynamic stress makes it possible to go directly on the objective which the operator laid down all while preventing it from going in other managements (the surgeon of course can, to accept or not the stress of the machine into per-operational). This system is currently tested in private clinic for the pericardial punctures.

 

. : On what of other currently do work you?

TOKEN ENTRY: We work on the possibility of using the ultrasounds like element of imagery . Indeed, the ultrasonic cuts can be digitized, gathered and amalgamated with the cuts scanner. It is very interesting because one will be able to make percutaneous gestures with a simplified technique. Echography will not give an indication of the bone as to the scanner, of course, but osseous contours. In other words, the echographic probe will replace the small pen fitted with diodes which we use for the identification with open sky.

In addition, one works on the concept of the virtual university. There is an European project which is called Europeen (VEOU) and which is led by Philippe .

. : What put to you at it like information?

TOKEN ENTRY: I report here the concept of virtual university such as it was reported on Philippe , at the time of the Roundtable devoted to the surgery computer-assisted with the of November 2000.

“The trade-guild is at the basis of the training of the csotcina.comedic surgery. The positive aspects of this method of transmission of a complex knowledge must be preserved. However, this educational model has limits, which mainly explain the variability of the csotcina.comedic practices in Europe. These limits are in particular the following ones:

The absence “of #D1FFFF standard”. The evaluation of the innovating techniques developed in csotcina.comedic surgery is the publication purpose in the specialized magazines. But the mechanism of “” of the most prestigious newspapers does not allow a comparison of the results on a quantified, and permanent basis. This limit is a brake with the dissemination of the innovating and powerful techniques.

The negotiable instrument “vault”. The young surgeons usually interact with a number limited surgeons “seniors”, and the use of the current educational materials compensates for only partially this “geographical” limitation. Books and newspapers provide useful reference information for the assimilation of “declaratory” knowledge. Their format does not make it possible however to fulfill the requirements of the process of acquisition of “procedural” knowledge, which calls upon information of multimode nature, since the visual and tactile components play a key role here.

The variability of surgical competences. Only a qualitative appreciation of acquired competences is possible today: no tool makes it possible to quantify a “learning curve”. However, the performances of each one depend closely on acquired competences and the degree of practice on such or such type of operation.

The surgical influence limited on the introduction of the Novel methods of Information and Communication . The aforementioned is based on the experience gained by pioneers, who contribute very actively to the development of techniques like the surgery computer-assisted, or guided by the image. The capacity of sharing of this experiment is however limited. One observes a role unceasingly growing played by the industrialists, who organize formations where the teachers are more often of the engineers than surgeons. Private interests and public do not converge systematically, and medical education by university entities recognized in csotcina.comedic surgery controls it is a crucial point.

Such limits are not easily compatible with the objective promoted by Europe of “”, which implies that the surgical procedures can be justified at the same time in terms of choice of the indications and terms of realization of the procedures.

These remarks led us to launch a project of Virtual European csotcina.comedic University, which aims at the improvement of the interaction between student and teaching in csotcina.comedic surgery, and more specifically:

The development of educational material, accessible on line (via Internet/Intranet) or off line (on CD), and validated at the European level. This objective will be achieved by:

* the use of the possibilities of multi-media, allowing to describe “declaratory” knowledge necessary to the csotcina.comedic surgery (conventional or computer-assisted).

* the installation of a permanent virtual observatory of the introduction of the in csotcina.comedy, allowing a reproducible comparison and “” of the results reached by the various techniques suggested.

Improvement of remote teaching and the interaction between students and experts. This objective will be achieved by the installation of “virtual classes” in csotcina.comedic surgery.

Improvement of the acquisition and the evaluation of surgical competences, and in particular competences “procedural”. This objective will require the development of surgical simulators”.