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René Louis has dedicated himself to spinal surgery, and has achieved international renown in this discipline. This recognition has been the fruit of relentlessly hard work, and of a realization early in his career of what it takes to be a spinal surgeon.
M.O. How did you become a spinal surgeon?
R.L. As an undergraduate and as a junior surgeon, I did not really know where I was going to go. My professor of Anatomy, Prof. Grisoli, was instrumental in showing me the way. It was he who gave me my first anatomy project, in 1956, when I was in my first year as a junior surgeon. He asked me to research the topography of the spinal nerve roots and the spinal segments, from the base of the skull to the pelvis, to determine their actual course and anatomical variations. He felt that this work would make a contribution towards more accurate information in spinal surgery. I searched the literature, and found that there was only one study upon which all the descriptions of the spinal nerve patterns with regard to the bony structures of the spine were based. This research, by Chipault, had been performed early this century, in a total of nine cadavers. All the "laws" of the distribution of the spinal nerves in relation to the spinous processes were based upon this very limited study. At the time, the work had been done to help clinicians who were taking their bearings from the spinous processes. I was asked to undertake this project at a time when spinal surgery, in the form of laminectomies, had come to be performed on a larger scale; also, the first procedures using an anterior approach had been introduced. It was, therefore, important for surgeons using a posterior approach to know the nerve root patterns in relation to the laminae rather than to the spinous processes. When using an anterior approach, it was also vital to know the spinal segments in relation to the intervertebral discs and the vertebral bodies.
R.L. With difficulty. The work involved the dissection of 30 cadavers, which meant close on 2000 nerve roots. I dissected the roots, and plotted them on graph paper, showing their course in relation to the laminae, the vertebral bodies, and the discs. I tried to determine the average pattern and some anatomical variations, and this allowed me to draw certain conclusions. When the site of the HNP is in the usual position, i.e. posterolateral, then the classical laws apply. However, if the site is more towards the midline, the herniated disc will impinge upon a root with a lower distribution. In this way, one may see an S1 sciatic pain pattern, whereas the compression is at a higher level - say, at L4-L5, in the midline. On the other hand, if the herniation is in the foramen, it will affect a root that comes from one level higher up. For instance, in the L5-S1 foramen, it will be the L5 rather than the S1 root that will be compressed and cause symptoms. Nowadays, this sort of approach is no longer all that relevant, since we have CT, which shows the actual site of the HNP and allows a ready comparison of the clinical and radiological features observed.
R.L. Yes, I had already opted for this career. I had seen all the different departments, and realized that my way of thinking was more akin to that of a surgeon than of a physician. After a few months spent dissecting spinal nerve roots, I realized that what I was seeing in my dissections was very different from what I had been taught by my professors, who were demonstrating lipiodol myelograms. I had a feeling right from the word go that there was new territory to be explored. I was certain that the anatomy of the spine had not been covered in great detail in the established texts because the surgeons had not told the anatomists what they really needed, and because anatomical research on the spine was not directed towards meeting the surgeons' needs. I realized this very early on; and once this had become clear to me, I decided to specialize in the spine. I went on to do a lot of work on the vertebral column, and I asked myself what one would need to do a proper job in this branch of surgery. I did a comparison between limb surgery and spinal surgery, and found that the whole approach, the logic, of surgery was different in those two territories. I realized that when those who taught me saw a patient with a disorder of the hip or the knee, they would outline a management policy that was logical and tackled the root cause of the condition; whereas, in spinal disorders, they might offer a laminectomy or sometimes fusion, but not something that would relate directly to the underlying lesion. I therefore thought that something should be done to enable surgeons to tackle lesions of the spine directly, at whatever level. I saw that where I worked the anterior approach was never used, and thought that spine surgeons should be able to use an anterior route to gain direct access to the lesions to be treated. The spine is like a long river that runs through several countries - it goes through a number of anatomical regions, from the mouth and neck, through the chest, the diaphragm, and the abdomen, to finish in the region of the pelvis. This meant that, in order to be a spine surgeon, I had to become versed in all these disciplines, rather than confining myself to the usual syllabus, which would not have enabled me to become an all-round spinal surgeon. So, from the outset, I made myself go through this process of multi-disciplinary training. I did neurosurgery, orthopaedic surgery, general surgery, vascular surgery, and ENT.
R.L. Yes. I took that decision back in '56, in my first year of surgical training. I had seen the literature then available, and come to the conclusion that there was something useful to be done in terms of research on the spine. When I saw that the internationally received wisdom on the spinal nerve patterns was based on a study done in nine bodies ... By the time I'd finished, I had dissected 100 bodies, which gave me an idea of just how diverse the anatomical patterns could be, and of how badly the textbooks can fail to reflect the actual situation. This study in a larger population showed that the average patterns needed changing. However, surgeons do not operate on average patterns, but on individual patients; so one has to be aware of the anatomical variations that may occur. This prompted me to do a lot of anatomical research before actually operating on patients, which meant that when I was performing surgery, the procedures were more rational than they would have been without this research. I went through many of the earlier textbooks, I looked at everything that had been written before on the anterior topography, with the distribution of vessels, their branches and anastomoses; and I redesigned the techniques for anterior approach, because what was available was not suitable for the spine. A chest surgeon goes in via a lateral incision in an intercostal space. However, that way one gets to the spine only side-on, whereas, for the treatment of some anterior lesions, the spine surgeon will need to be as close to the mid-sagittal plane as possible, so as to gain direct access through the vertebral body to the spinal canal, for decompression and for symmetrical reconstruction. Operating as close as possible to the midline is difficult, because of the way in which the large vessels course; however, once one has obtained control of these vessels, one has direct access to the spine, and one can tackle lesions in a way that makes mechanical sense and that is as rational as the procedures done in, say, the femur.
R.L. As soon as I had finished my surgical specialty training, I went on to specialize in Anatomy. I was a graduate assistant, and later, when I was sufficiently senior, a prosector. I went on doing anatomical research in the dissecting room in the afternoons; however, at that time we did not have enough bodies there, so I had to work at night in the morgue. So, three nights a week I would work in the morgue until three in the morning, in order to get on with my research. I kept this up for 15 years, and that way I was able to study the entire anatomy around the spine. I also went through earlier publications, which more often than not merely stated what was then the accepted state of knowledge; however, occasionally they allowed me to discover variations of which I had not been aware previously. I was able to develop my ideas, especially on the biodynamics of the spine and on the neuraxis; these were very original ideas that helped me greatly in my surgical activities.
R.L. Before becoming a Senior Registrar, I was made a prosector, and since my superiors had noticed my dedication to my work, I was very soon promoted to the grade of Lecturer in Anatomy. In other words, on the preclinical side, I had an academic post at senior registrar level before I reached that level on the clinical side. I was, as it were, out of synch with myself. At the time, I had been persuaded by Robert Debré to work full-time at a hospital, so there were problems regarding the equivalence of my preclinical position and my rank in the clinical hierarchy. I wanted to be a spine surgeon, which meant that I had to be an orthopaedic surgeon in addition to being an anatomist. However, under recent French legislation, it was obvious that the only combination possible was that of anatomist and general surgeon. No other specialty had been envisaged, and I was the first that had wanted a different combination. I had to add another two years to my time as junior surgeon, because there was no way in which I could sort out this teaching hospital hierarchy problem. So I waited one year, and then I went to the Department of Education, where I met someone called Mr. Salomon. I told him about my problem, and how the law was making it impossible for me to go for the career I wanted, and how the Medical School was telling me that my preclinical and my clinical positions were out of synch. Whereupon Mr. Salomon said, "Look here, I made these rules, and you are the first to raise this problem. Don't worry - I shall have an amendment published in tomorrow's Official Gazette; and you will have your appointment." So I made consultant two years later than I should have done; however, the additional two years at the middle level had allowed me to get exposed to all the different branches of surgery. Also, since I was well ahead on the academic career ladder, it was suggested to me that I should enter the agrégation examination to qualify for the title of professeur agrégé (Reader). I passed the exam after having been a consultant for only three years. That was back in '66. I immediately went to Senegal, since the job I was after was a teaching post at Dakar Medical School.
R.L. It was a transition period. Also, there was no age limit, and there was no time that had to spent at a given level before one could move up the career ladder. All one had to do was pass one's exams and to have published enough. I was able to sit the exam for the internat (required for going into specialty training) in my fourth year at medical school. And I was not the only one. So, 10 years after having passed my internat entrance exam, I had reached the rank of Reader. However, that was not at all unusual in those days.
R.L. That was together with Paul Bourret. He was our excellent professor of Neuroanatomy. He had noticed that I could draw on the blackboard, in my various anatomy exams, and had approached me about turning his lecture notes into a textbook. I was to be in charge of all the illustrations, while he was going to write the text relating to the figures. So I did all the artwork, rescaling the figures and changing them so as to have a standard colour scheme, while he wrote the entire text.
R.L. Even as a child, I could draw. Nobody had taught me, it came naturally. I would often draw when I was by myself. At school, I was often first of my class in Art. So anatomical drawing came easy, although I did have to work at it, because not all drawing is inborn. I learnt to do anatomical drawings, covering the anatomy from A to Z, by drawing and redrawing, and by establishing landmarks to guide my work. As a result, the anatomical patterns became so ingrained that even now you could ask me to draw any bit of the anatomy - the nervous system, the urinary tract, the blood vessels - and I could sketch them on the blackboard for you.
R.L. I had the necessary qualifications to sit the agrégation exam required for a readership; but I was too young, compared with my colleagues in Marseilles who were also taking the exam. I was told that there would not be a vacancy for me at Marseilles for several years; however, I could go away and try elsewhere, and then come back to Marseilles. At the time, there were openings in Overseas Development, so I applied for a post under this scheme, at the teaching hospital in Dakar. The job was just what I wanted, namely a combination of Anatomy and Surgery. There were five or six other applicants, but I managed to get appointed, and was delighted to go to Senegal. When I got there, I was made to work with Prof. Fustec, an excellent surgeon, who, sadly, was killed in a road traffic accident just three or four months after my arrival down there. So, young though I was, I found myself in charge of the Department. The unit had 100 beds, and I spent five years there actually running the Department.
R.L. At the start of the Overseas Development scheme, France was supplying the funding and the requisite personnel to enable us to do our job, which was to train new leaders for Africa and new professors for the medical school. Initially, the infrastructure was satisfactory, but the amount of work to be done was enormous. Also, we were pretty free to do as and what we liked, which meant that if one wanted to develop ideas and work hard, one had plenty of scope. The range of disorders to be treated was very wide, but management was not easy since patients tended to present at a very advanced stage. The cases of spinal TB that we saw would involve three or four vertebrae and major deformity, of a kind hardly ever seen in Europe. This obviously posed problems, but it was also a challenge to the surgeons, and made all of us think about how our techniques could be improved. Whilst we were reasonably well equipped in general terms, we did not have enough blood available for transfusions, which meant that I had to do my utmost to control bleeding during and after surgery. Any unnecessary blood loss had to be prevented - so surgeons had to be able to perform vertebral osteotomies (a three- to four-hour procedure) transfusing only one unit of blood. The skills acquired under those circumstances have come in very useful since then, and nowadays, with all the worries about blood transfusions, my anaesthetists are grateful that my patients do not need massive amounts of blood.
R.L. No, it was not. However, I had undergone training in neurosurgery, and the sort of haemostasis a neurosurgeon goes for is very much more meticulous than what an orthopaedic surgeon would want to achieve. So I decided to apply neurosurgical techniques to control bleeding, using electrocoagulation with bipolar forceps, rather than clamps. I had learnt how to do electrocoagulation layer by layer, and would never proceed to a deeper tissue layer while there was still the slightest amount of oozing at the higher level.
R.L. Yes, we had good operating theatres, and enough beds. What we did not have was adequate facilities for postoperative care. This meant that patients who had been operated on for spinal TB would be sent back to hospitals in the bush after having spent only two to three weeks at the centre in Dakar. They were discharged with a supply of antibiotics, but I had to work out ambulatory techniques, because I could not keep the patients in bed. This is how I came to develop distraction and lordosis braces, to enable the patients to walk around without putting undue pressure on the site of the operated lesion. This way, I was able to dispense with the classical way in which such patients were treated back home, in sanatorium-type facilities, where they were kept in bed for prolonged periods of time.
R.L. The majority of cases we saw were TB of the spine; however, there were also all the other disorders one would expect in a department like ours. When I went down there, I thought that slipped discs and scoliosis did not exist in Senegal. By the end of my first year, I had been confronted with the full range of disorders normally seen in Europe.
R.L. My management of spinal TB was an extension of what my predecessors such as Hodgson in Hong Kong or Ferrand in Algiers had done. They had practised what was then very advanced surgery, by approaching the lesion directly to excise it and to straighten out the deformities. Hodgson did the straightening by wedging rib grafts into the site of the lesion. Before going to Dakar, I had done reductions in cases of spinal TB or of fractures of the spine, by operating with the patient in traction. Traction was applied in both directions, and strong pressure was exerted perpendicular to the gibbus, which made the lesion open up like a book. The bone loss in such cases could be enormous, which is why I decided to insert bone harvested from the fibula, despite the notoriously poor behaviour of fibular grafts. However, at the sites where I was using these grafts, i.e. between healthy, freshened endplates, in the midline, and under compression, this was found to work all right, and excellent fusion would occur within four months from grafting, and the spine would be straightened out without any fixation devices.
R.L. There was intensive care, but of course not of the kind we have nowadays. I had a member of my medical staff who could monitor the patients; and, as I said earlier, surgery involved minimal blood loss, so we had very few instances of surgical shock, and things went very well postoperatively. Of course, surgery had to be meticulous, and patient selection extremely stringent. If there was the slightest contra-indication, I would not operate on that patient. It should also be borne in mind that the average age of our patients was quite young - my spinal TB patients were between 6 and 45 years old. I only did a very few who were in their 60's. Also, these people had tremendous physical stamina, and they were not mentally stressed by worrying about their operation. They trusted me, and had seen or heard that people who had been operated on by me did well. The fact that these were young, trusting, and highly motivated patients certainly helped to make our overall results as good as they were.
R.L. To be sure we did, in the early stages. The main problem I had to cope with was intra- and postoperative infection. After the first procedures I had done, I saw that healing was less than perfect, with a couple of little sinus tracts. I was told, "It's because of the climate; it's because that's the typical healing pattern in Africans; it's inevitable." I found out quite quickly that what it was really due to was poor asepsis. Also, my first attempts at plating vertebral bodies had led to suppurative complications, requiring removal of the hardware. That was no way to run a Department of Surgery. I therefore went in detail through our aseptic precautions in the operating theatre, insisting on proper technique with regard to gowns, masks, caps, the lot. And I introduced something that was new in Dakar - disinfection using formalin and ammonia. We did not have the modern equipment for disinfecting the theatres, so staff had to don gas masks and spray the solutions around every day using Flit-guns. During the first couple of years, formalin was first sprayed into the theatre, followed four hours later by ammonia to neutralize the formalin. Of course, this policy met with general resistance when it was first introduced, but I did the spraying myself the first few times, and then everybody followed suit. I then reviewed the way dressings were done. Within a few months, wound healing was no different from what it was in Europe, and I never again had any problems with postoperative infections.
R.L. Oh indeed, yes. I was also in charge of the Department of Anatomy of the Medical School. In my African patients, I repeated the studies I had previously done on my "Caucasian" population in Marseilles. This way, I was able to establish differences in the percentage distribution of anatomical variations. This was essential, because I really wanted to know what the possible variations were, before operating on patients. This research formed the basis of a book on anatomical variations in Europeans and in Africans. For the patterns in Asians, I had to go to other sources.
R.L. What I chiefly found was differences in the percentage distribution of anatomical variations. For instance, in Caucasians, the spinal cord finishes at the level of the L1/L2 intervertebral disc in 75% of the cases, and halfway down the body of L2 in 10% of the cases. In Africans, I found the end of the conus medullaris to be halfway down the body of L2 in 45% of the cases. As regards curvatures, I took a particular interest in lumbar lordosis, because what strikes Europeans about African women is their "swayback" posture, which, to a medical observer, might suggest hyperlordosis. I myself had made this mistake initially, and I went back over all the studies I had done on lumbosacral lordosis, especially in order to study the radius of the posterior arc and of the lumbosacral isthmus, which I had shown to go to an angle of 23° between birth and adulthood. When I reviewed these angles, I was surprised to find no evidence of hyperlordosis in African women, and to see that, with minor variations, the angles measured in the African subjects were the same as those seen in Europeans. What was different was the shape of the buttocks. African women have a body fat distribution pattern that makes for very prominent buttocks, and this mimics high-grade lumbar lordosis. So the conclusion from these studies, which I also published, was that the degree of lumbar lordosis in African women is the same as that seen in Europeans, but that the shape of the buttocks is different in African females.
R.L. I went back, and became Prof. Imbert's assistant, at the Hôtel-Dieu in Marseilles. Imbert was not doing very much surgery at the time, so that to all intents and purposes I was in charge of the Department. I went on perfecting all aspects of spinal surgery; in particular, I was refining my techniques for spinal fixation. I rapidly became aware of the importance of the papers and articles written by my late friend Raymond Roy-Camille, especially those that dealt with his technique for internal fixation of the spine. I became a dedicated disciple of Roy-Camille, and adopted his technique. It then occurred to me, by and by, that some of his hardware items should be modified, to make them suit my own techniques. I reduced the distance between holes in the plates, and added oblique holes for use in the sacrum. As regards grafting, I developed facet joint fusion. Using this technique, I was able to reduce the operative time required, since I could dispense with harvesting iliac grafts: I could use the spinous processes, cutting them into cortico-cancellous matchsticks to be fitted into the space between the joint surfaces. The chief advantage was that dissection did not have to be carried out beyond the facets; so, unlike the many surgeons who do intertransverse grafting, I could get away without interfering with the nerves and vessels supplying the paraspinal muscles.
R.L. At that time, the concept of instability was not what it is today. I would graft my patients whenever they had kyphotic or scoliotic deformities that needed correcting. The correction would then have to be maintained by means of spinal fixation and posterior fusion. If the reduction of a kyphosis involved loss of bone stock anteriorly, grafting and fixation from an anterior approach were required. Vertebrectomy always creates a global defect, and I needed to repair all three columns.
R.L. I did. Even before going to Dakar, I had once or twice tried a technique for interbody fusion from a posterior approach, which, at the time, was not called a Cloward but a Wiltberger procedure. What struck me was that in order to insert the very large iliac grafts, one had to do a major mobilization of the cauda equina; also, a lot of facets had to be resected. As an anatomist, I did not like that very much. I must admit that I very quickly gave up doing this procedure, and that I thought it more worthwhile to adopt an anterior approach, which did not require one to interfere with the nervous system.
R.L. Anyone who has studied the joints of fresh cadavers will know that human joints are not the same as man-made joints in machines: Human joints are not rigid. There is always a bit of play. In fact, that seems to be a fundamental biological law. One can readily observe this slack, for instance in the knee joint. The slightly flexed knee is not stable, and not rigid. I have found the same to be true of all the joints in the body. Equally, it is easy to see that the C1/C2 joint, a highly specialized joint designed for axial rotation, also allows 10° flexion-extension, and that the dens is able to move backwards and forwards behind the anterior arch of atlas, permitting a small amount of flexion. Quite clearly, joints in anatomy and joints in mechanical engineering are designed in different ways. If one looks at anatomy in purely engineering terms, and if one has not seen what the patterns are like in the actual human body, one may demand the same rigidity in the human body that one would require in a piece of machinery. If you have a steering wheel mounted on a shaft, you need a rigid connection, for any play in the joint would soon lead to wear and faulty movement. Now, in the human body, there is no such thing as perfect movement around an axis; it's all a matter of turning-gliding and ligamentous tension. This is why, in the spine, semi-rigid fixation very often results in sound fusion. Of course, this semi-rigid fixation must not be so lacking in rigidity as to cause excessive movement and, hence, non-union. It is tempting to tell a patient that because he has been treated with rigid fixation, he will not need bracing etc., and that he can move around any way he likes. However, I would warn against such an attitude, because if the hardware is very rigid, movement will occur between the ends of the hardware and the bone, and in the long run, the bone at these sites will inevitably be resorbed, causing pain.
R.L. What must be borne in mind is that even bony fusion is not wholly rigid; and even the tall skyscrapers can sway at the top. Nature has not produced anything that is completely rigid. The tibia of a skiing champion has to have a certain amount of flexibility, to cope with the stresses imposed on it during downhill skiing at high speed. This is why champion skiers have known for some time that they will have to have any internal fixation hardware removed in due course. Our young orthopaedic surgeons will need to be aware of these natural biological phenomena. The body does not have metallic rigidity; the body has biological rigidity, which is something very relative. So, if the metals that we implant are too rigid, and if there is a mismatch between the physical qualities of the human bone and the physical qualities of the metal, there will be interface problems. In actual fact, nature can cope with all sorts of non-biological situations, and complications will occur in only a small percentage of cases.
R.L. One thing that strikes visitors to my Department is that I do not use artificial intervertebral discs, or fusion cages, or artificial ligaments. Of course, one could put this down to me being an old fuddy-duddy, or to a Not Invented Here attitude on my part. I can assure you, those are not the reasons. I am very open-minded, and I have myself designed techniques and been happy to be allowed to use them - equally, I have given ideas to younger colleagues, to make them continue the process of invention and innovation. What I do think is that present-day trends are sometimes good, but there is a need for improvement. It is sad to see that the first designs incorporating these new ideas are not yet properly matched to the biomechanics of the spine. Thus, for instance, the artificial disc has a number of advantages: It restores disc height and, at the same time, the height of the foramina; in doing so, it also abolishes dynamic lateral stenosis. Its chief benefit is that it introduces an inert material between the arthrotic endplates, thereby removing one cause of pain. Because of all this, the initial results are, admittedly, very good. However, the problem is that the prosthesis has been designed in such a way as to have a centre of rotation that is equidistant from the endplates of the adjacent vertebrae. Now, anybody that has studied the biomechanics of the spine will know that the centre of rotation is closer to the endplate of the vertebra below the disc. If this were not so, the facet joints would be out of synch with the disc. The artificial disc imposes a movement centred on a point halfway between the endplates of the adjacent vertebrae, i.e. 3-4 mm higher than it ought to be, which interferes with the proper movement of the facets. Rotation is malaligned. At first, while there is still a bit of cartilage, the patient will not be adversely affected; however, the facet joints will soon become arthrotic, and the implant will inevitably wear. So, this is surgery that produces only short-term results - elegant, yes, but not lasting. Surgeons who use these prostheses know that, eventually, they will be able to fuse these patients. In other words, this is delayed fusion, but one that requires two operations.
R.L. Yes, in the early stages, when surgeons did not insert the prostheses properly. I have seen discs that were too far forward, with a totally wrong centre of rotation, plus the fact that the implant was not held in place by the edges of the endplates. Since these devices sit behind the aorta and the vena cava, it was quite frightening to see them stick out so. There again, some surgeons put the discs in too far back, which caused bulging into the spinal canal. By now, most surgeons have learnt to insert the devices reasonably correctly, so the only remaining problems, to my mind, are the faulty position of the centre of rotation, and wear. However, the discs are inserted from an anterior approach, and that route will be more or less ruled out in revision surgery, because adhesions with the great vessels cannot be taken down like adhesions elsewhere in the body. The patients need to be warned that they have undergone anterior surgery, and that, in all probability, a different route will have to be chosen in the event of a re-operation. By using an anterior approach, bridges will have been burnt. It remains to be seen whether that matters.
R.L. I have already had to remove some. People who have not understood the problem tend to think that these cages take the place of conventional fusion. However, that is a biological misconception, because without posterior fusion, or without at least immobilizing the patient for 6 months, you get the worst of all possible scenarios. There is micromovement; the endplates are not well vascularized; and the grafts cannot readily get through the narrow windows of the cage. All these factors give rise to painful non-union; and I have had to re-operate on patients, take the cage out, and do anterior regrafting. However, if it is intended to put in a cage to abolish micromovement of the anterior column in cases where posterior fusion has been used, that would be all right, because in such a case the cage would have only a minor mechanical role to play. Posterior fusion would mean that there would not be very much micromovement, and this misplaced graft would then have time to take by and by. A cage combined with fixation/posterior fusion is theoretically acceptable, because of its inherent advantage of restoring disc height. However, I have seen that this is rarely of any definite benefit, and that equally good results may be obtained with a posterior technique of nerve root release, without raising the endplate. We must tell our young colleagues that it is wrong to treat the spine as if it were a wrinkled face that has to be lifted in all people who, like myself, are over 60. One must not aim to restore all the intervertebral spaces for cosmetic reasons, because decompression with or without fusion, without restoring disc height, will give excellent results.
R.L. The problem with ligaments is as follows: We are supposed to put in artificial ligaments to treat instability caused by spondylarthrosis - because degenerative instability is spondylarthrotic instability. To show you what I mean, let us look at the knee: A patient with OA of the knee, with a varus or valgus deformity, will have articular surface defects that lead to loosening of the ligaments and, hence, instability. Would you then consider the use of artificial ligaments in such a patient, to restore proper joint tension? Of course you would not, because you know that the artificial ligament will give after some time, and that OA cannot be treated by restoring the ligaments but only by restoring the joint surfaces. Now, the spine has 23 discs; and if you put artificial ligaments on one or two motion segments, there are still all the others to compensate for your technical error, so that it will show less than if you had done something equally silly in the knee. However, as far as the principle goes, there is no difference in silliness. Also, if one were to try to restore stability purely via the ligaments between two vertebrae, one should imitate nature, because nature has put between any two vertebrae a huge ligament, the one with the largest cross-sectional area in the body - the annulus fibrosus. At the level of L5/S1, this intervertebral ligament has a transverse diameter of 6 cm, and an a.p. diameter of 3-4 cm, which means a cross-sectional area of almost 20 cm2. It is a circular ligament, which means that it can cope with movement in all directions. And then there are the other ligaments, which ensure all-round stability between any two vertebrae - the intertransverse ligaments; the ligamenta flava, which connect the laminae; the interspinous ligaments; etc. To want to replace Nature's own very sound and all-round solid design by a couple of artificial ligaments at the back, between the pedicles; to think that twice 1/2 cm2 could do the same job as a fibrous structure with a cross-sectional area of 20 cm2 - that's going way out on a limb. Like artificial discs, this is surgery that achieves brilliant immediate results that do not last. Let me ask our young colleagues: Is it really in the interest of our discipline to have techniques that yield short-lived results, and which threaten to produce any number of revision cases in years to come? For how long will we be able to keep the trust of our patients if what we tell them is, "The improvement you had from your operation unfortunately did not last. However, we've got another operation, which may work." I think that if we go down this road, if we fail to provide surgery that gives lasting benefit, we shall bring our discipline into disrepute.
R.L. There is one thing I have learnt in the course of my career, something that everybody is talking about but which, to my mind, is not being done properly, and that is the psychological approach to the conditions that patients are suffering from. For the past 15 years, I have worked side by side with a psychiatrist; and now I have reached a point where I can myself conduct a psychiatric interview with my patients. I am not talking about major psychiatric disorders. But many of our patients have minor problems, which are due to stress. Stress can cause pain. The process is one where a minor organic lesion which would not have been a huge problem in itself is blown up out of all proportion as a result of stress-induced chemical changes in the transmission of pain messages, which make this initially minor lesion intolerably painful to the patient. If and when medical treatments fail, this patient may seek help from a surgeon. If, then, there are some slight abnormalities on his or her X-rays, a slightly bulging disc, for instance, or a degenerated disc, then it may wrongly be concluded that there is a cause-and-effect relationship between such a lesion and the patient's pain complaint; and the patient may be operated on. And that would be disastrous, because far from being rid of his trouble, the patient would often be worse off after surgery than before.
R.L. I can think of about a dozen clues that allow one to identify the problem in just a few minutes. Looking for such clues is time well spent.
First of all, there is the patient's statement that he or she has been to many doctors, who have none of them been able to help: The usual treatments, i.e. analgesics and anti-inflammatories, have not worked; the only thing of benefit may have been steroids. Physiotherapy may have tended to make things worse. In such a case, one should start by asking the patient whether he or she tends to wake up early in the morning, between 4 and 5 o'clock, and then have difficulty going back to sleep. Nine out of ten will say that they do. Then, one should find out whether they feel very tired in the morning, although they should be feeling rested. Then, one would try to see if the patient is easily upset. If the patient's wife has come along to the consultation, she will often say, "Yes, he is very edgy." Female patients may often be very weepy in the mornings. These are the general features that one should be looking for.
Then, there are local phenomena, i.e. minor organic lesions that are exaggerated by neurochemical disturbances in the transmission of nerve impulses. These patients complain of pain that looks as if it were mechanical in origin, because it often takes the form of muscle aches, which, normally, would be worse following exercise and improved by rest. This can be very, very deceptive - one tends to equate muscle pain with a mechanical lesion. The thing is that these patients are in pain all the time, even when resting. Often, it is a burning sort of pain, and the pain pattern varies in time and space. What I mean is that sometimes the pain will be worse in the mornings, and sometimes in the evenings. It will be localized at a given site for a few days, and then change to the other side or to a different level. There may later be pain in a completely different territory. Then there are other kinds of pain, which the patients do not report spontaneously, because they have come to see their doctor about a particular pain, say, in the lumbar or the cervical spine. If one asks them, they will say that, occasionally, they do have pain in the foot or some other part of the body. Also, there are often vascular, vasomotor, manifestations - numbness or tingling in the arms and hands, parts of the limbs going numb. These symptoms worry the patients because they themselves, and some doctors, think that this is incipient paralysis. Terms such as paralysing sciatica may be used, even if all that the patient has is fleeting numbness, without any definite anatomical pattern.
By probing further, one will then be able to elicit the cause of the stress: a divorce, unemployment, a sick child that the parents have been looking after for years, etc. And once one has got that far, one can confirm one's diagnosis of stress-related pain by a trial treatment. For this trial, we use antidepressants and neuroleptics in very, very small doses - much smaller than the doses prescribed in psychiatry. The patients are put on this medication for a few weeks. If the patient comes back and reports relief of his or her symptoms, it is obvious that, in order to treat disorders of the spine, one has to be more than just a skilled mechanic - one needs to be an all-round doctor whose range of skills includes that of understanding the psychological aspects of the physical complaint.
That is the philosophy that I have distilled from 30 years' experience in spinal surgery.
