Total Hip Arthroplasty Using a Ceramic Prosthesis

Pierre Boutin (1924–1989) Pierre Boutin (Fig 1) was born in 1924 in Tours, in the Loire region of central France. He completed his scholarship in Tours and entered the Tours Medical School in 1943. In 1949, he moved to Paris for his internship. He married his wife Monique in 1950. Boutin’s son, Barnard, was born in 1951.Fig 1.: Dr. Pierre Boutin (photograph courtesy of Laurent Sedel, MD)In 1952, Boutin began his orthopaedic training at the Internat de Paris. He was trained in many of the orthopaedic departments in Paris including those of Robert Judet and Robert Merle D’Aubigne. In 1956, he moved to Pau, a town near the Pyrenees Mountains. He entered private practice at the Marzet Clinic, which was located near the CGE Co. (later called Ceraver). This was a large company known worldwide for its glass and ceramic products. After operating on the vice president of this company, Boutin and his patient began to discuss the possibilities of using an alumina-on-alumina hip prosthesis, instead of the metal-on-metal or metal-on-polyethylene prostheses that were available in France at that time. The first patent was obtained in 1970. Boutin implanted bulky pieces of alumina in dogs and even implanted a little ceramic ball into himself to check the biologic tolerance. In 1970, the first human implantation was performed using an alumina cup and a ceramic ball attached to a metal stem that was cemented in place. In the beginning, there were some problems with the femoral-stem fixation and some cases of fracture of the components. In 1972, he introduced a femoral component that was made entirely of ceramic. He continued to work on the improvement of the components with the help of D. Blanquaert using the biomechanical facilities of Laurent Sedel in Paris. For the next 20 years, Boutin, Blanquaert, and our team used the Morse taper, patented in Germany in 1970, and modified the stem to a collared, smooth anodized shape with 12 different femoral head sizes. Boutin was very active operating, writing papers, and doing research. He observed his patients very carefully and when he reoperated on them, he used the material to study the in vivo behavior of the material. He also worked in the public hospitals of Lourdes and Tarbes. Boutin was friendly, dedicated to his work, and very passionate. He always worked with his patients and in the emergency department. He was well respected by his patients, his colleagues, and by the entire French and European orthopaedic communities. He was a a member of the International Hip Society. Boutin died in 1989, several months after his retirement. Boutin was happy with the clinical success of his ceramic components, but was disappointed that they had never been marketed in the United States. Total hip replacement is not new since, as cited by Leinbach 1, it had already been done in 1890 by Gluck 2 : an ivory ball and socket were attached by cement in rosin, rock pumice in powder and plaster. But the first true prosthesis appeared in England and was put in place and used by Wiles 3 as early as 1938. In 1939 methylmethacrylate appeared as a method of sealing thanks to Habousch. 4 But it was in 1959 when momentum was truly contributed by Charnley 5 who used a socket of teflon receiving a ball made of stainless steel, each piece attached to the bone by methylmethacrylate. For reasons of toxicity due to the debris from wear and tear, he changed the teflon to high density polyethlene shortly after. McKee, 6 in 1966, introduced a metal-to-metal prosthesis made of an alloy of cobalt chromium also fixed by an acrylic cement. Each one had success in France with these two prostheses and Charnley 7 could say with pride “it is truly nice to know that they are both British!”. Since this date, many prostheses derived from one or the other of these have been put in place, particularly in Europe. However, as early as 1956 in the Soviet Union, Siwash 8 used a constrained metal-on-metal prosthesis anchored directly to the bone, the two prosthetic elements having holes and cracks which allowed bone regrowth. This prosthesis, at first done in an alloy of cobalt chromium is now made of much lighter titanium. This quick history of total arthroplasty highlights the considerable improvements achieved in the last few years. From a craftsman stage the fabrication has lead to an industrial project with all of its controls: resistance of the materials, index of rugosity (roughness), of circularity, coefficient of friction, wear, etc . . . which should not be surprising since it calls upon metallurgy of alloys, that of titanium, to the production of plastics and now to the high point in techniques of ceramics. The goal of the surgeon is to approach as closely as possible the inherent qualities of the joint articulation and in principles to replace only the worn out surfaces, in other words, the cartilage and subchondral bone, at least in the majority of cases. The difficulty of achieving a perfect liaison between the material and the living bone is perhaps the most arduous problem to resolve, if the permanence of such substitution is desired. Up to the present time, joint prostheses replace more than is necessary and despite this we have difficulties in assuring a strong attachment. The appearance of porous materials [Lyman-Smith 9] or rough, uneven ones [Galante 10] will probably allow for a small advancement. There remains another preoccupying problem of the tolerance of these implants which function under constraint and wear-and-tear. We don’t yet know the long-term effects on the organism of these plastics with complex molecular chains. We know more about the metal alloys, certainly well-tolerated but not sheltered from micro-corrosion as Ferguson 11 has shown. It is the same for titanium as Aragon 12 has proven. This microcorrosion is nothing but the natural tendency of the different components of an alloy to return to the previous state, by oxidation. To that is added what Fink and Smatco 13 call the corrosion of constraint which makes possible the development of fissures and the breakage of implants, true acceleration of the fatigue fractures of the metals. This is why many authors estimate that the majority of materials implanted in the organism, a corrosive environment with variations of pH, especially after trauma or intervention, cannot be tolerated indefinitely. Corrosion, constraint, and chemical degradation due to the action of fluids and body tissues on the prosthesis not only change the properties of it, but also the products formed can be toxic, leading to intolerance of the implant with aseptic phagocytosis then soon after, septic. (This is at least what we think.) Therefore it is very important when implanting joint prostheses to take it into the greatest consideration since our goal is a definitive replacement and not just a temporary one as it is for the material for fracture fixation. Thus, along with the problem of permanence of the tolerance of our implants, we also have that of the material-to-bone liaison. The use of ceramics may allow for progress in these two areas. In the first stage we developed a prosthesis of alumina, of which we will expose the mechanical qualities and the tolerance. In the second stage, after recognizing the American work, we will study the possibility of anchoring directly to the bone. I. THE TOTAL ALUMINA PROSTHESIS In April 1969, when we had thought about the possibility of using alumina as a prosthetic material, we only had in mind the use of its exceptional mechanical qualities and the goal of replacing the materials used up to that time. We wanted a prosthesis that we could qualify as traditional with a sealant of acrylic cement. 1. Physical characteristics of alumina Aluminum oxide or alumina (AL2 o3) occurs in the form of a fine white powder. After compression in a mold, the piece obtained is fritted by cooking in an oven at a low temperature to its point of fusion, 1700 degrees. A very dense conglomerate with little crystals on the order of 30 to 80 microns is obtained. Its density, 3.92 is almost that of monocrystalline of alumina that is found pure or colored (sapphire, ruby) in its natural state. Its spectrographic analysis shows that it is almost pure since it contains 99.3 p. 100 of alumina for: —0.6 of MG 0 —0.04 of SI 02 —0.03 of NA 0 —0.01 of F2 03 —0.005 of CA 0 Its mechanical characteristics are particularly interesting. Its resistance to flexion 4000 kg cm2 and to traction 2000 kg cm2 is much less desirable than that of a metal such as stainless steel. On the other hand, its resistance to compression 24000 kg cm2 is excellent Added to this remarkable point is its hardness since it is classed 9 on the MOHS scale, immediately below the diamond, classed 10. It is this extreme hardness which permits its use in cutting tools and in the manufacturing of the hardest metals. But it is also this property which makes it so difficult to rectify (straighten, adjust) and to cut, since a diamond must be used. No metal, not even tungsten can damage it. Like a very hard alloy or a tempered steel, alumina can be brittle to a violent or direct shock. But considering its thickness when used as a hip prosthesis this breakage is not likely if it is not hit directly with force. It has an advantage over metals and plastics in that it is non-deformable under shock, heat or pressure. This dimensional stability prevents a deformation of the active surfaces at the time of sterilization, cementing, or compression under use. This is an advantage for the quality of rotation, a disadvantage on plastics as far as elasticity is concerned. 2. Chemical characteristics As an oxide, alumina is by definition rustproof and cannot deteriorate, so it does not risk corrosion. Except for flourhydrique (hydrofluoric) acid, chemical agents do not harm it. This explains why such a neutral and inert body can be so well tolerated. However, the research of aluminum in the urine of our patients, accomplished by spectrographic analysis at the toxicology laboratory in Toulouse, is positive for some, negative for others. The tests for wear perhaps provide the explanation. Indeed there is wear of about 10 microns with emission of particles between 0 and 300 hours on a simulator. This research will need to be pursued in order to know if the spectrographique analysis still shows traces of aluminum in the urine alter a long period of use of the prosthesis; the causes for error are numerous. This amount of aluminum in the urine of patients was determined by emission spectrography, on dry residues heated to 400 degrees C. Out of 28 urine samples examined at that time, 12 presented an appreciable rate of aluminum (in the 16 other cases, the aluminum was below the sensitivity limit of the quantitative method, being 200 mg/liter of urine.) Trials of centrifugation and ultra-filtration (0.3 m) were carried out on urine that had been kept refrigerated for several days. The qualitative examination by spectrography of the residues of centrifugation reveal that they are strongly charged with aluminum. The quantitative research on the urine after centrifugation confirms in fact that the amount of aluminum had lowered considerably. These experiments however, do not yet permit characterization of the nature of the composite solids to which the aluminum is attached: alumina or phosphate for example. We envisage trials of characterization: —by diffraction X, —by difference of solubility. Recall that the nephron cannot let particles bigger than 75Å pass through. To better determine the eventual interactions between the alumina and the organism, we will the 1. In action of the on the ceramic used for the prosthesis 2. of this material in at the of 8 months and study of the of aluminum in the by the organism In and we several to the clinical We of a work carried out as early as by who of this tolerance and allowed to have less The implantation of a small and ball of dense alumina under the of a human to after its at the of 3 the of a hard of to each by an which not The implantation of small of alumina in the of several dogs the to the We also attached of which allowed to a very in a few but a violent It was the same with alumina powder under the of a But there was by of the prosthetic We were with the use of dense alumina for the implantation of the first prosthesis ball and socket are made of alumina the is The estimate that the resistance of alumina to flexion is probably to the stem with this material. The of alumina in an for the cement to its Its in is made to the alumina The two active surfaces are by a diamond which the quality and the of these two pieces in The alumina has a in which the of the of the prosthesis The is with a This does not in with the but we know from the work of that it is well tolerated and inert to the chemical The of these prostheses can be accomplished in an as with all or by in an or by In the last there is of to the molecular as with of the prosthetic It was accomplished by the A of the of the a in to its of an at 30 degrees in to a the is a second which is in by the action of a at the of this the head to be is of the attached ball on the of a with an of degrees. this is a of between the and the socket the of the attached the of a of pieces to in the two pieces are a a of at a A the of the which is and being of the of the of the ball in a of degrees at of between the ball and the socket of 100 in the of the in a of with added 300 and each were carried and of the ball and of the rugosity of the ball with the of the of the ball and The of and that the ball was A of 10 microns was for the first 300 This very 3 microns more between 300 and after hours and up to the of the of it has to do with of the surfaces in On the other hand, at all was on the the of and not The of rugosity on the ball a improvement of its index this of and 0 and 300 hours it from microns to 300 and hours it from microns to hours this The of the allow to that there was difficulty with the at The of the coefficient of carried out on a that it between and the found in having been In this well the of 3 months of and that this have continued to function for an After the surfaces are and all the were In we the of and of the alumina ball after The on the of the ball shows between 0 and 2 The is by the of on two the having the same the is We point out that these very could certainly be to the of total arthroplasty of the and put in place by those who it we to point out in those who are using the alumina prosthesis with cement. The first used is since there are of doing we use the the by approach or the by The of the femoral ball is at the of the cartilage and even the will the be in the of In most cases it does not necessary to several of the since this always a In the of the socket on one and the more or less of acrylic cement also allow for and of the On the other hand, the of the prostheses in two one with at the other for the it is not to the alumina with a Its hardness it into a which the metal can and worn by it. femoral and are It to the alumina must be the and the cement must not take which causes difficulty of From April to 200 prostheses were implanted and by an acrylic cement. Except for a fracture of the ball to the one by direct on to the metal and the ball at the time of the there have not been due to the materials at the time of in this the was immediately of this in the operating fractures have been on implanted and it very that such an from an shock. it is not possible for to about after of these prostheses has had to be It must be that prosthesis can a the risk of deformation of its which lead to an in the coefficient of and an acceleration of to metal and this new material used in total arthroplasty of the fritted alumina, to present a of which need to be These are its hardness which it perhaps for the of a its perfect chemical its low coefficient of and its tolerance by the But metal, it has the disadvantage of not having to The clinical of the first 100 prostheses implanted will be after two for the last that is in the same time that we were using this alumina prosthesis by this material for metal and we were also the research carried out on ceramics. appeared of The goal pursued by the American was that of permanence of the tolerance of the implants and The natural bone is in large of a ceramic material which by its it to that of the Since many ceramic are at the of and cannot they for the most and very so the research in this can difficult to After a few trials using to up the as early as it that the first ceramics were on by in on a porous ceramic made of alumina with It was not pure since it was a of a of alumina, and The material obtained was as hard as bone, had the same of and was strongly anchored to the bone to the point of being to It that this study allowed a more approach for the liaison of an prosthetic piece to living than with other material. In an important work of the present research and its also that the study of ceramics allow for the of the implantation of a total prosthesis in the hip of It is important to that in the United the problem of arthroplasty of the hip is in that the and the use of sealing up a few months This explains the success of 16 prosthesis in that The on ceramic material to the ceramic materials appeared to be very with the The by other that all ceramic material as a The porous ceramics have been to be of considerable of when the of the is microns and with of liaison on the order of 100 of ceramic material on a metal implant as a possible to the problems of of the tissues that the metals and These were from a of very the study of new bone in a very difficult problems due to the hardness of ceramic. the of a diamond the authors were to of about microns that they in which allow to the of the in these also use which a examination of the obtained. The present clinical still and to our prosthesis has yet been used. with this work of and of we will that of who research in a or a some on other on ceramics and metals. After these we are also the possibility of direct of the prosthetic 1. The dense fritted alumina is not so it to a direct In industrial techniques have not yet achieved a piece with the active made of dense alumina and the of porous We to this difficulty by the of on the of the dense alumina of alumina with a of on the were in the of The of the had been done with a In the the so that a and were necessary to The examination tolerance and of the of found between living bone and material. months other were with even more difficulty since the bone which had between the on a of the could not be from the ceramic. The examination allowed to of which the of the This in the Thus, even the of and of constraint at the of the can be we were to of an on the dense This allowed to envisage the of a with direct But this is not yet the the The metal on which the ball is does not to be directly attached it is known that some of prosthesis are very difficult to and they to the bone. since we of work the of a of porous ceramic on the metal, we began a new this This be not only for but also for achieving an to the risk of corrosion of constraint of the 2. prosthesis with direct This prosthesis from the by its which has a and a of which the is A is at the of the socket and is used to its which must all the to the This is only in cases the of the socket is The piece is then implanted after at so that it with hard Its the alumina and the metal are to the prosthesis to the cement. 20 of this have been implanted in those who have been of the to of it for The of this stability is difficult to only only the of time will permit The permanence of the of prosthetic pieces by a of a material and body must be our and in the research has to from its first and for the that it We to for his help in the Dr. for his Dr. for his and for in the of the prosthetic and who over the of these