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Características del TCH

1. Figure2 Fibrocartilage F al the contact of an HA TCP 5096 5095 implant 1 1 month after implantation Woven bone W is forming in the fibrocartilaginous tissue Silver methenamine Figure3 Dense fibrous tissue can be found at the contact of the same implant HA TCP 5099 5096 I in the early stages of the implantation 1 month Osteoclast like cells arrow are present very close to the material Silver methenamine Figure 4 Two months after implantation the control material C i surrounded by a thin layer of bone arrow in the medullary zone and by Haversian bone H in the cortical region Fuchsin toluidin thin trabeculae of lamellar bone were fixed on the external surface of the porous material in the cortical zone Figure 5 A very poor ingrowth could be seen inside the implant in the medullary region Figure 6 Some localized areas of the implant were surrounded by a dense connective tissue in both the medullary zone and Figure5 Bone trabeculae thick arrow coming from the cortical bone are in close contact with the outside surface of the HA implants 2 months after implantation The ossification found inside the ceramic is very poor thin arrow and the pores are filled with medullary tissue Fuchsin toluidin Figure7 Inside the pores of the HA implants after a period of 2 months the ceramic C can be seen at the contact of fibrous tissue F Pores are filled with adipocytes Fuchsin toluidin F
2. CE 0459 Sumario Caracteristicas del TCH Ceramica de sintesis Composici n qu mica Resistencia en compresi n Seguridad biol gica Experimentaci n animal Protocolo Resultados Osteoconduccci n Osteointegraci n Reconstrucci n sea Resorci n de la cer mica Revista clinica multicentra Resumen con respecto a 138 casos Publicaci nes KASIOS Mai 2003 Caracteristicas del TCH Ceramica de sintesis Composici n qu mica 75 Hidroxiapatita HAP 25 Fosfato Tricalcico TCP Formas granulos de 2 3 mm bastonillos bloques cylindros cu as Porosidad interconexa 60 80 Tama o de poros 200 a 500 micrones Esterilizaci n Rayos Gamma con una de dosis minima de 25 kGy Resistencia en compresi n 1 a 5 MPa granulos bastoncillos gt 5 MPa bloques cu as cilindros 1 Cer mica de s ntesis La cer mica es una materia inorg nica que no es met lica elaborada artificialmente partiendo de mezclas de minerales en polvo dentro de una argamasa consiguiendo una suspensi n liquida cuya temperatura y presi n se ven aumentadas para realizar el proceso llamado sinterizaci n Se distinguen entre las cer micas las cer micas de s ntesis o cer micas t cnicas que difieren de las cer micas artesanales al ser elaboradas de forma industrial con lo cual est n controladas la composici n de las mezclas y las etapas de la sinterizaci n Una cer mica esta caracterizad
3. r rmat n 1 1 ty v culame R sorption de la c ramique lect semaine on lk rit 1Li 10 tariqku dont la structure macroporcu L evolution da Y i pp o ACTUALITE us mes a D Figure 8 Absen ce d oss otemden tion A Figure Comparnison FCH Substitut osseux de Granul s de c ramique biphas e 75 Ces synth se HAP 25 TCP Arthrod se tibio calcan enne E E Ost otomie F morale A Fracas m taphysaire du tibia TRAUM TOLOGIE Trous de 6 mm combl s KASIOS Mai 2003 50
4. 0 3 and 1 All the manufacturing processes except the composition of the powder were the same The com position of the specimen was assessed by X ray diffraction quantitative determination Figure 1 Biomaterials 1993 Vol 14 No KASIOS Mai 2003 40 424 Osseointegration of ceramics P Frayssinet et al 34 000 46 000 gt x 2 theta y 239 Linesr lt 34 000 26 000 gt c Figure 1 X ray diffraction spectra of the calcium phosphate used for the experiment a Pure HA implant b 75 HA 25 B TCP e 50 HA 50 TCP x 2 theta y 199 Linear Control material Cylinders of cancellous bone were stamped from sheep bone They were then sintered for 4 h at 600 C Implant procedures Calcium phosphate cylinders were implanted into the left hindleg of sheep with a lateral approach of the femur 9 mm diameter holes were drilled with a skull trepan into the cortical bone of the medium diaphysis Each implant was inserted inside the bone until it reached the opposite endosteum No implant micromovement was allowed once the implant was in place One implant of each group was implanted into three sheep for four periods of time 1 2 4 and 9 months For these implant procedures two zones were differentiated in the implant cortical and medullary Biomaterials 1993 Vol 14 No 6 Histological analysis Immediately after the animal s death thick sections were made from the femurs con
5. L activit classique ce stade est relativement limit e concerne que ments formes lors ge de la cavit En fait la c ra mque ex praliquement intacte avec des grains polvcristallins et joints de grains non alt r s OSTEOINTEGRATION Rappelons que ce terme d signe l tat d un implant colonisable entierement envahi par le tissu osseux qui s est form sa sur Lace sans interposction fibreuse A 12 semaines d implantation la repous mire des ramique sont bl s fig cas les Contacts os imuleriau enticrcinci con n 3 Dans tous les sont tres tendus et directs sans interposition fibreusc L im plant est donc bien ost oint gr On note une fragmentation de la amsque H s est produit e un remeodelage du tissu os seva unmalure mooterme NY A Figure 3 On ointegranon PH ex i sem Mos race de ta c ramique Fraga A Figure d Ou aint gration et remodelage en siie cortical er blo par du TON 42 se vhs MM Mad VIE TE ems de av hen m wale Fever mit ww a al ON Du M Remodelage ver y D Figure Ost oint creation et remodelage en sale spongieux Fron em site spongieur da a 12 webo mir A Figure 6 Remedelage FOH en site Remodelago artagu pur Les KASIOS Mai 2003 49 ux ls imm diat trou yu model lerne assurera terme l ancras im pk l Your vea n En site spon
6. 47 Nancollas G H In vitro studies of calcium phosphate crystallization in Biomineralization Chemical and Bio chemical Perspectives Eds S Mann Webb and R P Williams VCH Publishers NY USA 1989 pp 157 189 Metcalfe J C Moore J P Smith G A and Hestketh T R Calcium and cell proliferation Br Med Bull 1986 42 4 405 412 Posner A S Bone mineral and the mineralization process Bone and Mineral Rescarch 5 Ed W A Peck Elsevier B V 1987 pp 66 115 Frost H M Tetracycline based histological analysis of bone remodelling Calcif Tissue Kes 1969 3 211 219 Amsel S Maniatis A Tavassoli M and Crosby W H The significance of intramedullary cancellous bone formation in the repair of bone marrow tissue Anat Rec 1969 164 101 112 Biomaterials 1993 Vol 14 No 6 KASIOS Mai 2003 46 170 Utilisation d une c ramique macropo reuse biphas e en dehors de la trauma tologie a propos de 126 cas J P MEYRUEIS A CAZENAVE B LE SAINT J GADEA F BARBIER Toulon Depuis novembre 1992 nous utilisons comme substitut osseux une c ramique biphas c TCH sous forme de granul s associant deux phosphates de calcium 75 p 100 d hydroxyapatite qui donne au produit une bonne r sistance la d gradation 25 p 100 de tricalcium phosphate rapidement dissous en lib rant des ions qui activent l ost og nese Cette c ramique de synth se dont la porosit est d environ 80 p 100
7. 80 60 40 20 0 Month 1 Month 2 Month 4 Month 9 Percentage of the implant perimeter at bone contact cortical region Implants Control El 100 HA El 75 HA E 50 HA Porcentaje del per metro del implante en contacto con el hueso neoformado La cer mica bifasica TCH asocia en su composici n optimizada dos sustancias cuyas propiedades se completan persistencia en el tiempo para la HA y fuerte bioactividad inmediata para el TCP KASIOS Mai 2003 5 3 Resistencia en compresion Como toda cer mica macroporosa el TCH es fr gil Su resistencia en compresi n es del orden de 1 5 MPa granulos bastoncillo y gt 5 MPa bloques cilindros cu as mientras la resistencia del hueso esponjoso fresco varia de 1 a 15 MPa EI TCH no debe ser utilizado directamente en compresi n a menos de que un dispositivo met lico placa fijador externo venga a actuar como puente para evitar que las presiones provoquen un aplastamiento de las ceramicas Las propiedades mecanicas de la ceramica implantada mejoran sin embargo rapidamente como lo demuestran los trabajos del Sr TRECANT la colonizaci n sea transforma la cer mica en un material cuya resistencia en compresi n aumenta proporcionalmente con el tiempo Compressive Strength Mpa 0 2 4 6 8 10 12 Implantation time weeks Compressive strength of the MBCP as a function of the implantation time at an osseous site and muscle site o Resistenci
8. THE CERAMIC 2 MONTH IMPLANTATION PERIOD 100 HA 75 HA 25 8 TCP SOT HA 50 6 TCP g of contact a thickness Fig 1 Osseointegration in the cortical bone A of the pyro lised cancellous bone serving as control material B and implanted for 2 months The control material is perfectly osseointegrated fuchsin 310 material For these implant procedures wo zones were differentiated in the implant a cortical and medullary zone Histological Analysis Immediately after the animal s death thick sections of the femurs containing the implanted material were made The specimens were fixed in 596 buffered formaldehyde then dehydrated in alcohol and embedded in polymethyl methacrylate Further sections were made to obtain a 50 jum thick section These were surface stained with cither fuchsin toluidine blue or silver methenamine and observed with a light microscope Some sections stained with silver methenam ine were carbon coated and cxamined by back scatter scanning electron microscopy SEM on an ISI SS60 JEOL Courbevoie France oper ated at 25 kV One specimen of each chemical composition implanted for 4 months was oxidized with a 5 sodium hyposulfite solution These anorgamic specimens were then observed with a scanning electron microscope GEOL JST 200 JEOI Courbevoie France operated at 25 kV Image analysis was performed on sections of material implanted for 2 months Four zones were chosen at random
9. c ramique Une ost osynthese stable a t r alis e syst matique ment Une d cortication a t pratiqu e chaque fois qu elle tait possible 25 pseudarthroses ont t class es en cat gorie T2 et 5 en T3 23 taient D et 7 D 5 pseudarthroses taient septi ques et 25 aseptiques Comblements type Papineau par c ramique autogreffe 4 observations entrant dans les cat gories T3 et D R SULTATS Toutes les fractures ont consolid dans des d luis normaux l exception d une fracture m taphysaire du f mur distal qui a volu vers la pseudarthrose Dans un cas un cou lement aseptique temporaire s est accompagn de l limination spontan e de quelques grains Dans un autre cas une biopsie r alis e lors de l ablation du mat riel a confirm la parfaite in t gration de la c ramique Les pseudarthroses ont consolid entre 3 et 8 mois l excep tion d une pseudarthrose septique Dans deux observations cor respondant deux greffes massives de c ramique un liser p riph rique est toujours visible sans cons quence clinique Dans les Papineau le comblement a t obtenu dans les d lais habituels DISCUSSION Dans le traitement des fractures les facteurs ost oinducteurs sont lib r s par la fracture elle m me La c ra mique remplace l autogreffe et constitue l indispensable support ost oconducteur lorsqu il existe une perte de substance Dans les pseudarthroses les facteurs ost oinducteurs doiv
10. filled the whole volume of the macropores and had the same aspect as the adjacent cortical bone The bone layer coating the surface of the material located in the medullary zone was thinner than during the former period 50 80 um Figure 17 Resorption marks were visible in the ceramic Figure 18 In some pure HA implants a bone ingrowth could be shown op 100 F so o Percentage so 20 r Month 1 Month 2 Month amp Month 9 Time months Figure 16 Percentage of the implant perimeter at bone contact medullary zone Implants IB Control ES 100 HA 75 HA amp 50 HA Thickness um e v E v o Month 9 Month 4 Time months Figure 17 Thickness of the lamellar bone at implant contact medullary zone Implants IB Control El 100 MA C 75 HA 50 HA tut En Ker y E SO um Figure 18 Resorption marks arrows in HA TCP 75 25 ceramic C 9 months after implantation Bone B fills the cavities dug in the ceramic Silver methenamine Biomaterials 1993 Vol 14 No 6 KASIOS Mai 2003 44 Osseointegration of ceramics P Frayssinot et al Figure 15 Connective tissue filling the pores of the pure HA implants 4 months after the implantation 2 3 mm inside the ceramic but the percentage of the surface coated by bone did not differ significantly from the HA ceramics implanted for a shorter time Figure 19 The inside por
11. la r activit de certaines apatites hydroxyl es carbonat es ou fluor es alcalino terreuses Th se de Doctorat d Etat Universit Paul Sabatier Toulouse Toulouse France 1972 Bonel G Heughebaert J C Heughebaert M Lacout LL and Lebugle A Apatitic calcium orthophosphates and related compounds for biomaterials preparation Ann NY Acad Sci 1988 523 115 130 LeGeros R Z Calcium phosphate materials in restorative dentistry a review Adv Dent Res 1988 21 164 180 Frayssinet P Hanker D Hardy D and Giammara B Novel methods for demonstration osseointegration of hydroxylapatite coated titanium hip prostheses in Proceedings of Electron Microscopy Society of America Forty Ninth Annual Meeting 1991 Ed G W Bailey San Francisco Press San Francisco CA USA pp 34 35 Salyer K E and Hall C D Porous hydroxyapatite as an onlay bone graft substitute for maxillofacial surgery Plast Reconstr Surg 1989 84 2 236 244 Exsli P S Muller W and Schenk R K Porous hydroxyapatite and tricalcium phosphate cylinders with two different pore size ranges implanted in the cancellous bone of rabbits Clin Orthop Rel Res 1988 232 127 137 Legros R Apport de la physico chimie l tude de la phase min rale des tissus calcifi s Th se de doctorat d Etat Institut National Polytechnique de Toulouse Toulouse France de Groot K Bioceramics consisting of calcium phosphate salts Biomaterials 1980 1
12. ne contient ni matrice prot ique ni moelle osseuse et met donc l abri des r actions immunologiques des transmis sions infectieuses et des maladies prions L exp rimentation animale a montr qu 12 semaines l int gration osseuse tait totale MAT RIEL ET M THODE Dans une s rie de plus de 300 cas provenant de 4 sites nous avons retenu les 126 cas por tant sur 115 patients ne concernant pas directement la traumato logie et ayant plus de 1 an de recul Le recul maximum tait de 7 ans La s rie comporte 61 femmes et 54 hommes L ge mini mum tait de 14 ans maximum de 88 ans et moyen de 51 ans Les Indications ont t 108 fois un comblement 32 reprises de proth ses 31 hanches et un genou en association avec la mise en place d une nouvelle proth se rev tue d hydroxyapatite 23 tumeurs dont 3tumeurs malignes 28 comblements de d fects osseux apr s ablation de mat riel et 25 comblements de zones de pr l vement osseux 8 arthrod ses et 10 ost otomies ont t r alis es avec une ost osynth se stable et en associant la c ramique aux fragments d os r s qu s pour combler les pertes de substance Localisation 101 cas concernaient bassin ou membre inf rieur 24 le membre sup rieur et 1 cas le rachis La Classification GESTO a t utilis e sauf pour les reprises de proth ses 22 cas taient class s D et 73 D 76 cas taient TI 19 T2 La c ramique a t plac e 40 fois en os spon
13. on cach section They were analyzed by a photometric system of image analysis The polygonal outlines of im plants and bone tissuc were created by thresh olding The lengths of the implant and the bonc outline were determined automatically The per centage of the perimeter of implants in contact with bonc tissuc and the mean thickness of the bone at the point of contact were calculated Table RESULTS After a 2 month implantation period all the implants seemed macroscopally to be osscoin tegrated Light microscope observation showed a complete osseointegration of the control mate rial both in the cortical bone Fig 1 and in the medullary tissue A thin layer of lamellar bone was visible at the point of contact of the pyrolised cancellous bone Implants of 100 HA were in contact with bone in the cortical region Some thin trabeculae of lamellar bone were fixed on the porous material surface in close proximity to the corti cal bone Fig 2 No bone tissue could be shown inside the implant in the medullary region Some localized areas of the implant were sur rounded by a dense connective tissue both in the medullary zone and in the cortical region Fig 3 Some macrophages and multinucleated cells could be found resorbing the matenal HA grains were found inside these cells Implants containing B TCP either 25 or SO P TCP were in contact with lamellar bone tissue in the medullary zone Fig 4 and with haversian bone Fig 5 in t
14. EM microphotographs the bone matrix was clearly distinguishable from the ceramic and bone was KASIOS Mai 2003 43 Osscointegration of ceramics P Frayssinet et al 100 pn Figure 12 Osseointegration of an HA TCP 50 50 implant 1 4 months after implantation The pores of the cortical region are filled with Haversian bone H and the medullary region is coated with a thin bone layer arrow Fuchsin toluidin attached by some focussed points of contact to the ceramic Figures 13 14 The amount of bone at the contact of the material in the medullary zone was less than in the implants containing TCP implanted for 2 months Pure HA implants were situated in a dense connective tissue environment in both the medullary zone and the cortical region and showed poor osseo Integration Figure 15 Figure 13 SEM microphotograph of an anorganic preparation of the bone coating B of an HA TCP 50 50 implant ih Figure 14 Higher magnification of the same region 427 There was no significant change in the percentage of the implant surface at the contact of bone either for pure HA implants or for implants containing 8 TCP between the 2 and 4 month implantation periods The bone ingrowth into the different ceramics implanted for 9 months did not differ from that of the ceramics implanted for 4 months Figures 6 16 The bone tissue found in the cortical region of the two groups of ceramics containing TCP
15. a en compresi n del MBCP MBCP TCP vs tiempo de implantaci n en emplazamiento seo y en emplazamiento muscular KASIOS Mai 2003 6 4 Seguridad biol gica 4 1 biocompatibilidad La introducci n del TCH en el organismo no provoca reacciones Cuando el TCH se disuelve libera los iones de calcio y fosfato id nticos a los que ya se encuentran normalmente en la sangre En consecuencia no presenta ninguna toxicidad El uso ortop dico de los fosfatos de calcio es autorizado por la FDA desde 1982 El TCH es un injerto seo de s ntesis que al contrario de los injertos de origen animal o humano no lleva sustancia org nica alguna susceptible de provocar una reacci n inmunol gica del organismo 4 2 Contaminaci n Al contrario de ciertos injertos seos de origen animal o humano el uso del TCH no presenta riesgo alguno de contaminaci n microbiana viruses o priones La Esterilizaci n se hace mediante rayos gamma de una dosis m nima de 25 kGy seg n la Norma EN 552 Un detector de esterilizaci n se cambia al rojo cuando el implante ha recibido la dosis requerida El acondicionamiento se hace seg n la norma NF S 90 438 2 con un doble envase est ril y una caja de cart n recubierta de un pl stico etiquetado en conformidad con las exigencias esenciales de la directiva europea 93 42 CEE El modo de empleo dentro de la caja esta en conformidad con las exigencias esenciales de la directiva Todo frasco de TCH debe ser obliga
16. a por su microestructura que describe la ubicaci n de los cristales de polvo sus dimensiones su composici n y las relativas proporciones de fase cristalina e amorfa En regla general en una cer mica los cristales de minerales granos en polvo se encuentran soldados entre si por una fase amorfa que tiene la estructura de un vidrio constituyen las juntas de los granos cuyas composiciones son funciones de los granos y de la suspensi n EI TCH es elaborado con un polvo obtenido por precipitaci n qu mica Este polvo es mezclado con agua y con un agente porogeno bajo el aspecto de bolitas calibradas Una sinterizaci n de 1200 C permite una solidificaci n de la suspensi n por sublimado del agente porogeno y fusi n parcial de los cristales La utilidad del agente porogeno reside en la obtenci n de poros interconectados de controladas dimensiones Poros interconectados KASIOS Mai 2003 3 La macroporosidad del TCH ha sido establecida para conseguir una colonizaci n sea optima Todas las publicaciones reconocen que la talla optima para los poros se situa entre 200 y 500 micrones La interconectividad de los poros permite un crecimiento 6seo que se realiza por penetraci n progresiva de la periferia hacia el centro del implante 2 Composicion quimica El TCH es una cer mica bifasica por consecuente realizada por una mezcla de fosfatos de calcio 75 de hidroxiapatita o HAP 25 de fosfato tricalcico o TCP La mez
17. ai 2003 12 Revista clinica multicentra Resumen con respecto a 138 casos 196 pacientes intervenidos entre el 1 04 93 y el 31 08 97 El estudio se ha realizado con 121 pacientes intervenidos entre el 1 04 93 y el 31 10 96 con una perspectiva de 10 a 53 meses El estudio se ha hecho en 59 mujeres y 62 hombres de 14 a 94 a os de edad El TCH ha sido implantado en 138 emplazamientos anat micos habiendo algunos pacientes con varias implantaciones El seguimiento ha sido hecho de forma continuada y sin ning n criterio de exclusi n 1 Emplazamientos Los emplazamientos son muy diversos como indicados en el dibujo n 1 2 Indicaciones Las indicaciones estan reunidas en los dos cuadros siguientes Cirugia as ptica 128 casos Fracturas diafisarias 12 Fracturas epifisarias 28 Pseudoartrosis 17 Tumores benignos 09 Metastasis 04 Injertos 17 Injertos despu s de AMO 11 Reintervenci n de pr tesis total de cadera 15 Osteotomias 03 Artrodesis 10 Tope de retenci n de cadera 02 Cirugia s ptica 10 casos Fracturas abiertas 04 Fracturas recientemente infectadas 01 Pseudoartrosis infectada 01 Osteltis del tibia distal 03 Artrodesis de la rodilla 01 KASIOS Mai 2003 13 03 01 11 07 02 06 04 03 03 13 FT AE 0r Emplazamentos Implantaciones 14 KASIOS Mai 2003 2 1 Traumatologia En traumatologia una osteosintesis ha sido siempre asocia
18. alcium phosphate ceramics as hard tissue Prosthetics Cha Orthop 1981 157 159 178 5 Klein C de Groot K Weiqua C et al Bone formation in non osseous tissues vn dogs induced n porous calcium phosphate ceramics Preseated at the Fourth World Bio matenale Congress Berlin Germany April 1997 6 Bernacte Assolam D Bioceramics processing Eur Mater Rex Soc Monogs 1991 1111 167 7 Trombe JC Contribution l tude de la d composi non el de la r activt de certaines apatites hydroxyl es carbonot es ow fluordes alcalino terreuses Toulouse France Umiverut Paul Sabatier Toulouse 1972 Thesis oatheghosphates related compounds for biomaterials preparation Annals of New York Academy of Sciences 1988 523 115 130 9 Legeros RZ Calcium phosphate materials in restora tive dentistry a review Advances in Dental Research 1988 1 164 180 10 Salyer KE Hall CD Porous hydroxyapatite as an onlay bone graft substitute for maxillofacial surgery Plastic and Reconstructive Surgery 1939 2 216 244 11 Eggi PS Muller W Schonk RK Porus hydroxapatine and incaleram phosphate cylinders with two differem pore size ranges implanted ia the cancellous base of rabbits Clin Orthop Rel Res 1988 232 127 137 12 Legros R Apport de la physico chimie l tude de la phase min rale des tissus culcifi s Toulouse France Institut Nacional Polytechnique de Toulouse 1987 Thesis 13 de Grom K Bioceramics consisting of calcium s
19. alts Biomaterials 1980 1 47 52 14 Nancollas GH In vitro srudies of calcium crystallization In Mann 1 Webb RAP Williams edis Biomineraliywion Chemical and Biochemical Perspectives New York VCH Publishers 1989 157 189 15 Metcalfe JC Moore JP Smith GA Hesketh TR Cakiem and cell proliferation Arinsh Medical Bulletin 1986 42405 4172 16 Poseer AS Bone mineral and the mineralization process Bone and Mineral Research 1987 566 115 17 Frost HM Tetracycline based histological analysis of bone remodelling Calcif Tissue Res 1969 3 211 219 313 KASIOS Mai 2003 39 423 Osseointegration of macroporous calcium phosphate ceramics having a different chemical composition P Frayssinet J L Trouillet N Rouquet E Azimus and A Autefage D f Rte d Espagne 31100 Toulouse and Ecole Nationale V t rinaire de Toulouse Toulouse Calcium phosphate macroporous ceramics are biocompatible for bone surgery Their osseointegration is however sometimes very poor To measure the effect of the calcium phosphate content of the ceramic on its osseointegration macroporous ceramics differing in their chemical composition were implanted into sheep femurs The ceramics were composed of different percentages of hydroxyapatite HA and f tricalcium phosphate J TCP All other characteristics were the same Results were assessed histologically with image analysis and showed significant differences in the amount of
20. an had been thought The role of the TCP phase on the inflammatory response and on the differentiation of osteogenic stem cells has yet to be defined but could be very significant REFERENCES 1 Moore D C Chapman M W and Manske D The evaluation of a biphasic calcium phosphate ceramic for 10 11 12 13 14 15 16 17 19 429 use in grafting long bone diaphyseal defects J Orthop Res 1987 S 356 365 Stahl and Froum S J Histologic and clinical responses to porous hydroxylapatite implants in human peridontal defects Three to twelve months post implantation J Periodontol 1987 8 10 569 695 Klein C P A T Patka P and Den Hollander W Macroporous calcium phosphate bioceramics in dog femora a histological study of interface and bio degradation Biomaterials 1989 10 59 62 Jarcho M Calcium phosphate ceramics as hard tissue prosthetics Clin Orthop 1981 157 159 178 Klein C de Groot K Weiqun C Chong Z Zhou Yubao L and Xingdong Z Bone formation in non osseous tissues in dogs induced in porous calcium phosphate ceramics in Proceedings of Fourth World Biomaterials Congress Berlin Germany April 1992 p 261 Bernarche Assolant D Bioceramics processing properties in biomaterials degradation fundamental aspects and related clinical phenomena Eur Mater Res Soc Monogr 1991 1 111 167 Trombe J C Contribution l tude de la d composition et de
21. anas Crecimiento seo masivo Principio de reconstrucci n seo haversiano perif rico Fragmentaci n y reabsorci n importante del material OA hueso primitivo de tipo cortical ON hueso neoformado H reconstruci n haversiano C cer mica 3 Reconstrucci n sea En la cortical al cabo de 12 semanas el hueso es de tipo laminar con un principio de organizaci n haversiana a la periferia En la esponjosa la neoformaci n sea se orienta hacia el tipo trabecular 4 Resorci n de la cer mica Al cabo de 12 semanas se nota una fragmentaci n de la cer mica cuya estructura macroporosa desaparece el componente tricalcico notablemente soluble en el pH del organismo est en fase de resorci n aguda como indica la presencia en el sitio de varios macrofagos cargados de material ex geno La reconstrucci n es un fen meno global los osteoblastos activos son visibles tanto en la superficie de la cer mica que en la superficie del hueso imagen n5 KASIOS Mai 2003 11 Imagen n reconstrucci n sea al cabo de 12 semanas Reconstrucci n sea los osteoclastos destruyen el hueso inicial los osteoblastos depositan el hueso nuevo Resorci n de la cer mica actividad cl sica contra la cer mica actividad fagocitar a intensa de los macrofagos cargados de material ex geno OI hueso inmaduro Oc Osteoclasto Ob frente de mineralizaci n osteoblastico M macr fago C cer mica KASIOS M
22. anufacturing processes except the composition of the powder were the same To assess the composition of the specimen rocnigen ray diffraction quantitative determina tion patterns were recorded on a gomometer Phillips TW1050 Roentgen ray emission wax obtained by a cobalt anode A 178892 nm Control Material Cylinders of cancellous bone were stamped out from sheep bone They were then sintered for 4 hours at 600 C in onder to remove the organic matrix from the implant Implant Procedures Calcium phosphate cyl inders were implanted into 9 mm holes drilled into the cortical bone of the medium diaphysis of sheep femurs Each implant was inserted msde the bone until it reached the opposite endesicum No implant micromovement was allowed once implanted Thirty sheep were used for this experiment Four sheep were i with cach kind of implant for 2 and 4 months Six sheep were implanted with the control 309 KASIOS Mai 2003 35 ORTHOPEDICS INTERNATIONAL EDITION Juty AUGUST SEPTEMBER 1993 VOL NO 4 Table Fig 2 Bone apposition A on the 100 HA ceramic B at the zone of contact between the ceramic and the bone tissue The implant surface that was not initially in contact with bone after the implantation is generally free of bone apposi tion fuchsin toluidine blue x 250 PERCENTAGE OF THE PERIMETER OF IMPLANTS IN CONTACT WITH BONE TISSUE AND THICKNESS OF BONE TRABECULAE COATING
23. arecen Han desaparecidos los bordes geom tricos y se han fundido en una masa poco densa en la cual no se les puede localizar Traveculas seas en continuidad con las de la esponjosa salen del sustituto seo La cer mica en este estado ha sido perfectamente integrada y sigue el proceso de reabsorci n Radiograf a al cabo de 21 meses KASIOS Mai 2003 26 Artrodesis de la muneca poliartritis rumatoide CAR 02 94 Mu eca rumatoide con importantes destrucciones osteo articulares Artrodesis con avivamiento de los huesos del carpo Osteosintesis por placa S1 Maconor 2 Relleno con TCH de los intersticios Resultados clinicos al cabo de 21 meses mu eca estable e indolora Radiografia de frente postoperatoria Radiografia de perfil al cabo de 21 meses KASIOS Mai 2003 27 Poliartritis rumatoide Artrodesis interfalangiana del pulgar despu s del fracaso de 2 autoinjertos JOL 03 95 osteosintesis por broches y relleno con TCH puro Resultado radiol gico al cabo de 3 meses granulos de TCH forman una masa ribete distal al cabo de 6 meses consolidaci n al cabo de un a o pulgar indoloro y estable Radiograf a al cabo de 10 meses KASIOS Mai 2003 28 Artrodesis tibio calcanea HEB 05 96 Necrosis astragalina bilateral en una joven de 38 a os por lupus eritytematoso Astragalectomia osteosintesis por tornillos relleno de las perdidas de sustancia por TCH puro Carga indo
24. at two processes are involved The homogeneous decrease of the ceramic density on the edge of the implant shown by back scatter SEM reveals a process of dissolution of the ceramic KASIOS Mai 2003 45 Osseointegration of ceramics P Frayssinet ot al proportional to the nature and the surface of the material This process seems to take place at the grain boundaries and some multinucleated cells detach the ceramic grains from the regions which have weak grain boundaries The extent of the cellular degradation of the HA implants seems to be greater than that of the implants containing fi TCP No dissolution process was histologically visible on the HA implant sections Some bone ingrowth in the resorbed zones shows that a remodelling process of the ceramic exists which is identical to the bone remodelling process first described by Frost The bone ingrowth and the osseointegration of the ceramics are completed a few weeks after implantation Only remodelling processes occurred after the earlier osseointegration of the material this led to a densification of the bone tissue in the cortical zone of the implants containing B TCP and to a thinning down of the bone layer adsorbed on the medullary part of the ceramics The poor bone ingrowth shown in the pure HA material did not increase as the period of implantation extended However the cell degradation of the ceramic persisted throughout the whole implantation period The ossifica
25. bone formed at the contact of the different ceramics Ceramics containing B TCP induced better osseointegration than pure HA ceramics Keywords Ceramics hydroxyapatite tricalcium phosphate osseointegration Received 27 October 1992 accepted 9 November 1992 Calcium phosphate ceramics especially hydroxyapatite HA ceramics are used as bone filling biomaterials As with the manufacturing process of every ceramic material three main stages are required for their elaboration The material initially ln a powder form is shaped at room temperature into the definitive part for the third stage the part is sintered to oblain the fusion of the grains of the material and eliminate the internal microporosity During this process the physical and chemical characteristics of the material can change The final calcium phosphate material can have very different characteristics One of these is the chemical composition of the material This depends only partly on the composition of the initial powder Non stoichiometric HA is relatively unstable At ca 900 C some other phases tricalcium phosphate calcium oxide can appear Even perfectly stoichiometric HA may give rise to an oxyhydroxyapatite al temperatures gt 1000 C or to tricalcium phosphate and tetracalcium phosphate at 1570 C Analysis of commercially available HA for bone substitution showed that the chemical composition of the material was different from that of a supposedly
26. by Frost CONCLUSIONS The presence of various calcium phosphate phases in a bioceramic influences more than the physio chemical properties of the material In this study the adjunction of B TCP to the HA increased the solubility of the B TCP containing ceramic but also dramatically increased bone ingrowth in the ceramic pores The so called bioactivity of the calcium phosphate biocer amic depends greatly on its calcium phosphate phase content This specification needs to be better defined than it is today Most of the HA products commercially available contain vary ing percentages of TCP Moreover the inter action between calcium phosphate products and cells could be much more complex than was thought The role of the B TCP phase on the inflammatory response and on the differentia tion of osteogeme stem cells has yet to be defined but could be significant REFERENCES Y Moore DC Chapman MW Manske D The evalua don of a biphasic calcium phosphate ceramic for use in ae diaphyseal defects J Orthop Res 1987 2 Stabl SS Foum SI Histologic and clinical responses 10 porous hydroxylapaiite implants in human pendoesal defects Three 10 twelve months postimplaetatioe J Perio dontal 1987 10689 695 CALCIUM PHOSPHATE CERAMICS 3 Kkin CPAT Paka P Dea Hollander W Macro porous calcuam phosphate bwoceramics is dog femora a histological study of interface and biodegration Biomaten als 1989 10 59 62 4 Jarcho M C
27. cabo de 19 meses fotograf a Radiograf a postoperatoria Al cabo de 3 meses Al cabo de 7 meses los bordes de los gr nulos se vuelven borrosos Se encuentran conectados por traveculas oseas que aseguran su integraci n Al cabo de 5 meses aparici n de un callo interno y consolidaci n de la misma Una masa correspondiente a gr nulos interconectados se encuentran en la linea de osteotom a Al cabo de 19 meses fusi n entre el material de sustituci n y la cortical que se encuentra reforzada en el sitio de la fractura KASIOS Mai 2003 19 Radiografia al cabo de 7 meses Radiografia al cabo de 19 meses KASIOS Mai 2003 20 Fractura compleja de la extremidad superior del tibia con perdida de sustancia metafisaria GOI 02 95 Osteosintesis por placa Resultado radiol gico al cabo de 3 meses consolidaci n Traveculaci n al cabo de un a o fotograf a Radiograf a al cabo de 12 meses Radiograf a al cabo de 24 meses despu s dela ablaci n del material KASIOS Mai 2003 21 Fractura muy desplazada e irreductible de la cabeza del humero CRO 01 93 Osteosintesis por placa y relleno de la cavidad con TCH Resultado radioldgico en postoperatorio al cabo de 13 meses al cabo de 25 meses despu s de la ablaci n del material de osteosintesis fotografia Despu s de 13 meses se observa una alteraci n de la forma geom trica de los granulos cuyos bordes desaparecen Los granulo
28. cla de estos dos fosfatos de calcio es quimicamente muy cercana de la composici n de la parte mineral del hueso que es una apatita carb nica Las velocidades de disoluci n de los fosfatos de calcio son diferentes En el pH del organismo la HA es muy poco soluble y permanece durante varios a os Su presencia asegura al implante una cierta perennidad El TCP es muy soluble en el organismo Cuando se disuelve libera iones de calcio y iones de fosfato que pueden promover la osteog nesis Efectivamente se considera que los iones de calcio son los precursores de ciertos mecanismos de diferenciaci n de la c lulas osteoprogenitoras en las c lulas oseas Por otro lado la saturaci n en iones favorece la precipitaci n de microcristales de fosfato de calcio cristales que se vuelven centros de nucleaci n en la osteog nesis El TCP es altamente bioactivo Solubilidad 4 5 6 7 8 pH solubilidad vs pH KASIOS Mai 2003 4 La elecci n de unas proporciones 75 HAP 25 TCP es consecuencia de los trabajos de Frayssinet La osteointegraci n exprimida por el porcentaje de superficie del implante en contacto con el hueso neoformado es medido despu s de 2 4 y 9 meses para cer micas cuyas composici n en HAP varian de 100 75 y 50 La osteointegraci n de la HAP pura es siempre muy baja independientemente del tiempo Las cer micas bif sicas presentan sin embargo excelentes resultados 75 HAP siendo el mejor compromiso 120 100
29. da con TCH En medio s ptico la osteosintesis ha sido realizada con un fijador externo de tipo FESSA En todos los casos el TCH ha sido utilizado para rellenar el espacio que existla entre el hueso esponjoso y el canal medular 2 2 Reintervenciones de pr tesis Para las reintervenciones de pr tesis cimentadas el TCH ha sido utilizado para rellenar los espacios en el cotilo 2 3 Asociaci n TCH hueso esponjoso El TCH ha sido utilizado solo 117 veces asociado con hueso esponjoso o hueso cortico esponjoso del mismo sujeto 10 veces asociado a un injerto heterogeno 11 veces 3 Resultados 3 1 resultados cl nicos Tolerancia Ninguna reacci n inflamatoria cut nea ning n derrame s ptico o as ptico han sido encontrados cual sea la localizaci n o la indicaci n La excelente tolerancia ha sido confirmada por las implantaciones en medio s ptico en particular en el caso de 3 oste tis tratadas por Papineau Consolidaci n Las fracturas diafisarias han sido declaradas consolidadas al cabo de 3 o 4 meses La formaci n y mineralizaci n del callo seo se han producidos en plazos normales El relleno por importantes perdidas de substancia diafisarias ha sido siempre seguido de una consolidaci n a corto plaza aproximadamente 3 meses Tal ha sido el caso con perdidas de sustancia cortical lateral donde la cer mica ha remplazado el injerto de hueso esponjoso con los mismos resultados Pero el TCH no es suficie
30. e outline were determined automatically The length and the mean thickness of the bone were calculated at the point of contact of the implant Statistics From both parameters the mean values and SEM were calculated Comparison of the means was performed according to Student s t tables RESULTS Histological sections of ceramics implanted for 1 month showed a loose connective tissue filling the pores of the material Some zones of dense connective tissue were found close to the material Very small zones of cartilage and fibrocartilage were also found in the pores of the material or at the interface of the ceramic and the cortical bone Figures 2 3 No difference in the histological structure of the t ssues surrounding the three kinds of implants could be seen Osteoclast like cells were found close to the ceramics Figure 3 After a 2 month implantation period all the implants appeared to be macroscopically osseointegrated Light microscopic observation showed complete osseointegration of the control material both in the cortical bone Figure 4 and in the medullary tissue Figure 4 A thin layer of lamellar hone was visible at the contact of the surface of the pyrolysed cancellous bone The whole surface was coated by the new bone layer Bone was located at the contact of some parts of the surface of 100 HA implants in the cortical region Some KASIOS Mai 2003 41 Osseointegration of ceramics P Frayssinet et al
31. el hueso cortical reconstituido Los gr nulos implantados en la medula son transformados de la misma forma cuando se encuentran cercanos al sitio de la fractura A cierta distancia no parecen sufrir colonizaci n sea 4 Complicaciones Los resultados postoperatorios han sido siempre buenos La tolerancia es excelente No han sido se alados ninguna complicaci n general o local ninguna reacci n inflamatoria ninguna infecci n incluso en el caso de fuerte sepsis Radiologicamente no han sido observados complicaciones algunas ninguna lisis cortical ninguna periostitis ninguna migraci n de gr nulos ning n osteoma en gr nulos aislados ning n ribete KASIOS Mai 2003 16 Conclusiones Con una perspectiva de mas de 4 a os para los casos mas antiguos el TCH injerto seo de s ntesis ha dado hasta hoy entera satisfacci n Ceramica de sintesis el TCH no presenta riesgos infecciosos Perfectamente biocompatible no provoca reacci n inmunitaria En los 138 casos de esta revista este material osteoconductor ha sido utilizado solo o en asociaci n con hueso esponjoso para rellenar espacios seos y aisladamente en reemplazamiento del hueso esponjoso en traumatolog a para fracturas recientes Aun poco conocida esta utilizaci n permite simplificar los actos operatorios evitando los extracciones en particular en el hueso il aco El TCH es un soporte osteoconductor No debe ser ut
32. ent tre ap port s par une autogreffe ou par d cortication Dans les Papineau la c ramique permet une conomie importante d autogreffe N DU CODE 0871 1 KASIOS Mai 2003 48 ACTUALITE ETUDE EXPERIMENTALE D UNE CERAMIQUE MACROPOREUSE BIPHASEE JP MEYRUEIS A SOHIER MEYRUEIS M THERIN Clinique Saint Michel Toulon 83 Biomatech Chasse sur Rh ne 69 ous avons realise experimentation animale d une c ramique macroporeuse biphasce de Synthese avant ses essais cliniques Cette c ramique ICH est constituee de 75 d hydroxyapatite pour 25 de beta tricalcium phosphate selon les resultats experimentaux obtenus par Frayssinet La porosite totale est d environ SOK avec des macropores interconnectes de 200 a S00 microns La c ramique se presente sous forme de granules de 3 millimetres Les implantations ont ete realisees chez le mouton suivant un protocole tres simple Des defects cylindriques de omm de diametre creus s en diverses localisations osseuses corticales ou spon gieuses ont ete combles par des granules de ICM des prelevements histologiques ont ete reali Ses 6 et 12 semaines et compares avec Cevolution de cavites identiques non comblees Nous ne detaillerons pas ici cette experimentation animale Il nous a par contre semble interes sunt d illustrer par quelques resultats hi tologiques de ces implantations les d finitions et cer taines descriptions de notre a
33. es of the HA ceramics were filled with connective tissue The control material showed signs of cell degradation by macrophages and osteoclasts Figures 20 21 For all groups of ceramics giant cells and macrophages containing a great amount of refringent particles were visible in the connective tissue or n the medullary tissue of bone which invaded the ceramic even in the adypocytes of the medullary tissue DISCUSSION Calcium phosphate ceramics are known as being particularly osseocompatible However the osseo integration of this material is not always very good Wo have already analysed histologically some apatitic materials implanted In humans and Included In a fibrous tissue Other failures of the osseointegration of calcium phosphates can be found in the literature It is very difficult to find a common cause for all these failures The diversity of the specifications of the calcium phosphates implanted prevented any linkage between the biological result obtained and a particular charac teristic of the material Osseointegration of calcium phosphate ceramics has been proved to depend on the pore size and the chemical u A mms Figure 19 Osseointegration of the outside pores of pure HA implants 9 months after implantation B bone Fuchsin toluidin Biomaterials 1009 Vol 14 No 6 Figure 20 Degradation of the control material 9 months after implantation Bone B surrounds the material which persists in the medulla
34. est to the bone mineral other calcium phosphate phases can be used in the composition of onmhopaedi biomaterials The two most frequently used phases are B TCP and HA Some of their physio chermical properties are different The solubility of B TCP at the physiological pH is greater than the solubility of the HA This property could interfere with the ossification process at the point of contact of the implant The Ca being a secondary messenger for cells TCP could interfere with cell differenti ation sb its pomi of Moreover the supersaturation of the extracellular medium for Ca and P around the implant could be increased making collagen mineralization casier We could not show a greater material resorp tion for the TCP containing implant in this study Both pure HA and j TCP containing implants shows that two processes are involved The homogeneous decrease of the ceramic den sity on the edge of the implant as shown by back scatter SEM reveals a dissolution of the material This process seems to take place at the contact KASIOS Mai 2003 38 FRAYSSINET ET AL grain boundaries The importance of the cellular of the HA implants seems to be greater than in the B TCP containing implants No dissolution was visible histologically on the HA implant sections Some bone ingrowth in the resorbed zones shows that a remodeling process of the ceramics exists identical to the bone remodelling process first described
35. evens sin cer su wea es a veces min pobre Para medi vri de la composici n del fosfato caterer del mute rial cer mico en su integraci n aves se implantar cer micas macropordsicas de diversa compusicinn quimica en femures de ovejas Todas las siras caracteristicas eran iguales Los resultado fuero evaluados histoloicumente usando el an lisis de imagen y mostraron diferencias significativas en la cantidad de hueso formado al contact con bos diferentes tipos de cer micas Trai sdluteul boy An Nees APTO Materinli cermmict macroporest n hase di fosfato di calcio hann alista tratos di cyserr hiocompati KASIOS Mai 2003 34 FRAVSSENLT ET AL CALCIUM PHOSPHATE Ceramics bilit in chirurgia ortopedica tuttavia l integrari ote osea di questi materiali talvolta molto scarsa Ver valutare gli effetti della composizione di calcio fosfato del materials ceramico sulla sus osteointegrazione sono stati impiantati in femori di pecaro materiali ceramici macroporosi di com ponizione chimica differente Tutte le altre carat teristiche erano le stesse 1 risultati sono stati valutati istologicamente usando sistemi di analisi d immagine e si sono mostrati sgnificativamente differenti per quanto riguarda la quantit di osso formatosi a contatto con differenti materiali cer amici Translated by Pier Giorgio Marcheiri MD alcium phosphate ceramics and cspe cially hydroxyapatite HA ceramics are now used as bone filli
36. gieux 37 fois en os cortico spongieux 13 fois en os cortical et 5 fois en zone cortico m dullaire La c ramique a t associ e 12 fois des greffes osseuses R SULTATS Aucune complication en rapport avec le substi tut n a t observ e Les comblements pour reprises de proth ses sont stables L aspect radiologique sans liser avec fusion des grains est en faveur d une ost oint gration I en est de m me pour les comblements de tumeurs b nignes Un sepsis a n cessit une r intervention Un kyste an vrysmal m connu a continu a voluer et va tre repris Les arthrod ses ont toutes fusionn a l exception d une arthrod se scapho lunaire qui a volu vers la pseudarthrose serr e Aucune fracture it rative n a t observ e apr s comblement sur ablation de mat riel DISCUSSION Lors des reprises de proth ses les granul s de c ramique ne sont utilisables que pour combler les pertes de substances cavitaires Leur possibilit de migration intra articulaire doit tre limin e si n cessaire par une mince colle rette de ciment Les allogreffes conservent leur place dans les grandes destructions osseuses Dans tous les autres cas la c rami que biphas e utilis e a permis d viter la prise d autogreffe avec ses complications et l utilisation d allogreffes avec ses risques potentiels N DE CODE 0870 0 0871 0 KASIOS Mai 2003 47 92 Utilisation d une c ramique macropo reuse biphas e en trau
37. he cortical region Most of the implant surface was surrounded by bone tissue Some immature bone was found inside the implant resulting from the ossifica tion of a dense connective tissuc This direct ossification seemed to be the only way in which bone formation took place at the point of contact of implant no enchondral ossification could be shown Some osteoblasts were immobilized on the implant surface Fig 6 synthesizing an KASIOS Mai 2003 36 FRAYSSINCT ET Al Caccium PHOSPHATE CERAMICS Fig 5 Dense bone tissue A with some haversian zones 10 surrounding p TCP containing implant after a 2 month period of implanta tion silver methenamine x 2501 Fig 3 Connective lissue A surrounding the 100 HA implant C in the medullary zone fuchsin toluidine blue x 250 Fig 6 Osteoblasts O immo bilized on a amp TCP contain ing implant 1 after a 2 month period of implantation silver methenamine x 900 Hg 4 Lamellar bone A fixed on a B 1CP contain ing implant D in the medullary region after a 2 month implantation period fuchsin toluidine blue x 2501 Fig 7 Resocbed zone in B ICP containing implant 2 months after implantation Osteoclast like cells O are found resorbing the ceramic l silver methenamine x700 osteoid matrix Osteocytes were also found in close proximity to the material Resorption resulted in some localized areas from a cellular process Fig 7 Mult
38. igure 8 Bone ingrowth in the cortical region of an HA TCP implant 50 50 1 2 months after implantation A Haversian bone arrows structure is attached to the ceramic The medullary cavities are very important M Fuchsin toluidin in the cortical region Figure 7 Some macrophages and multinucleated giant cells were found to be resorbing the material HA grains were found inside these cells Lamellar bone layers were adsorbed on the surface of the implants containing TCP 75 HA 25 TCP and 50 HA 50 fi TCP in the medullary zone Haversian Biomaterials 1993 Vol 14 No 6 KASIOS Mai 2003 42 Percentage e Month 4 Time months Figure 6 Percentage of the implant perimeter at bone contact cortical region Implants IS Control 9 100 MA EZ 75 HA ES 50 HA bone was adsorbed on the implant in the cortical region Figure 8 Most of the surface of the ceramic pores was coated by bone tissue Figure 6 Some immature bone was found inside the implant pores which seemed to result from the ossification of connective tissue This direct ossification seemed to be the only way in which bone formation took place at the implant contact point no enchondral ossification could be shown at this stage Some osteoblasts were Immobilized on the implant surface synthesizing an osteoid matrix Osteocytes were also found close to the material Figure 9 Resorption marks were detected on the
39. ilizado aisladamente en casos de pseudoartosis donde una osteoinducci n es necesaria En todos los casos tiene que ser asociado a un autoinjerto de hueso esponjoso con una osteosintesis estable El xito del TCH en las reintervenciones de pr tesis de cadera tiene que ser confirmado por una perspectiva mas importante y si se demuestra que este material de sustituci n puede remplazar el hueso la ventaja de esta cer mica seria realmente considerable El 31 de Agosto del a o 1997 KASIOS Mai 2003 17 Fractura compleja del Femur distal en hueso osteoporotico MEY 08 93 Osteosintesis lamina placa y relleno por TCH en la cavidad centromedular Recuperaci n r pida de la carga muy buenos resultados Resultado radiol gico en postoperatorio al cabo de 4 meses fotograf a al cabo de 7 meses Al cabo de 4 meses se observa que los granulos se quedan integrados del lado interno del f mur donde se encuentran las tensiones mas importantes Tendencia a la corticalizaci n Bajo la placa donde existe un cortocircuito de las tensiones los gr nulos conservan una cierta individualidad Radiograf a al cabo de 4 meses KASIOS Mai 2003 18 Osteotomia femoral FOU 05 95 Osteosintesis lamina placa y granulos de TCH en la linea de osteotom a y bajo periostio interno Resultado radiologico en postoperatorio fotograf a al cabo de 3 meses fotograf a al cabo de 7 meses fotograf a al
40. implant surface Resorption resulted in some localized areas from a cellular process Multinucleated cells with an osteoclast like or giant cell Figure 10 appearance were shown resorbing the material Back scattered SEM investigation of the im plants containing B TCP showed details of the resorbing region The material was initially dissolved at the grain boundaries The ceramic became less dense in the dissolution regions Figure 11 some multinucleated cells then penetrated into the porous material and into the phagocytosed calcium phosphate grains The apposition of bone on the material protected it from grain boundary dissolution A calcifying extracellular matrix was very often inserted into the resorption lacunae being dug in the ceramic The remodelling process taking place inside the ceramics seemed to be the same for both kinds of specimens containing P TCP after 2 months of implantation The pure HA specimens showed resorption without bone remodelling or bone ingrowth into the ceramic Figure 9 High magnification light microscopy picture of bone tissue B at the contact of an HA TCP implant 7599 2595 Osteocytes O are visible close to the ceramic Silver methenamine Biomaterials 1993 Vol 14 No 6 Osseointegration of ceramics P Frayssinet et al Figure 10 Giant cells G at the contact of an HA TCP ceramic C 7536 2596 2 months after implantation A collagen network N is shown in the connective tissue su
41. inucleated cells with an ostecclast like appearance were shown resorbing the material A uniform dissolution resulting from a physical process was also observed at the showed resorption without bonc remodelling or implant surface bone ingrowth into the ceramic Hack scattered SEM investigation of e TCP The percentage of the implant surface in con comaining implants showed details about the tact with bone varied greatly according to the revorbing region The material was initially dis chemical composition of the material After 2 solved at the grain boundanes The ceramic months of implantation pure HA implants had became less dense in the dissolution regions Fig only a small percentage of their surface at the 8 then some multinucleated cells penetrated into point of contact of bone tissue Table Implants the ponmus material and phagocytosed calcium containing f TCP had much more bone tissue phosphate grains The apposition of bone on the fixed at thew surface The percentage of the material protected it from grain boundary dissolu surface at the point of bone contact increased uon The calcifying extracellular matrix was greatly when TCP was present in the chemical inserted into the resorption lacunae being made in composition of the material Table However the ceramic The remodelling process taking place there was not a significan difference in the inside the ceramic seemed to be the same forthe thickness of bone trabeculae absorbed on the tw
42. lora a los 3 meses Resultado radiol gica Al cabo de 5 meses la fusi n de los gr nulos es completa en la zona posterior de tensiones y de contacto En la parte anterior cerca de la movilidad medio tarsiana la fusi n de los gr nulos es menos avanzada Radiograf a a los 5 meses KASIOS Mai 2003 29 Fractura abierta con perdida de sustancia por maquina de serrar BOI 03 95 Relleno posterior por esponjosa del mismo sujeto hueso il aco y anterior por TCH Dibujo Osteosintesis por placa y fijador externo Resultado cl nico al cabo de 2 meses incorporaci n del TCH callo al cabo de 6 meses ablaci n del fijador Forma de los gr nulos queda aun visible lejos de la cortical al cabo de 1 afio ablaci n de la placa del peron Cortical densa traveculaci n a nivel medular Radiograf a antes de la ablaci n del fijador d ESPONJOSA x g T 1 y LY A Y Can ow KASIOS Mai 2003 30 Biopsia del tibia al cabo de 1 ano BOI 03 95 Toma de 3 5 mm de diametro a nivel medular dibujo El extracci n esta constituido por hueso travecular denso cuya estructura haversiana es muy clara H El TCH esta fuertemente alterado El componente tricalcico ha desaparecido y los fragmentos de ceramica persistentes estan constituidos por hidroxiapatita Algunos fragmentos estan integrados en el hueso con ausencia de interposici n fib
43. ly in the amount of TCP contained in the material into xhecp Implants were then histol ogically analyzed using image analysis after different periods of implantation MATERIALS AND METHODS Macroporous Calcium Phosphate Ceramics RIUM S h 2 U Zf p n AN GAN 492321 TAREE LIMITES TENDENTE LOL ONE RROD Abo Y MARIA MURO ORE ESS 25 LIST ME L GA SA 50571 qHUKO SI ZM p Vy Le te XO RETZ A LA EPR MOTS HIS LA KEW MENS EGOERATAN SORELLE 40 MM LF iv 7 OMR ORO LT 1 MIER ARROZ fhe Translated by Katsuji Shimizu MD Pure HA powder Bioland Dijon France was obtained by a double decomposition method Pure B TCP powder Bioland was blended with HA powder to obtain two different mixtures containing 75 HA 25 B TCP and 50 HA 50 B TCP respectively The macro porous specimens were manufactured according to classical processes A slurry made from the different powders water and additives was prepared This solution then was organized to obtain an inital ceramic shape The final sinter ing stage gave a 100 crystalline calcium phosphate material Using this technique cylinders with a diame ter of 9 mm and a length of 10 mm were made A porosity consisting of interconnecting macro pores from 300 to 1500 jam was produced all the pores were interconnected The resulting porosity was 70 Three types of implants were made having different calcium phosphate phase composition Their TCPYHA ratio was O 14 and 1 2 All the m
44. matologie A propos de 108 cas J P Meyrueis A Cazenave B LE Saint J GADEA Toulon Dans une s rie de 210 observations d implantation d une c ramique macroporeuse biphas e de phosphates de calcium en suivi continu sur 3 sites avec un recul d passant 5 ans pour certains dossiers nous avons isol les 108 cas ayant plus d un an de recul et concernant la traumatologie MATERIEL ET M THODE Notre s rie comprend 74 Irac tures 30 pseudarthroses et 4 greffes type Papineau Le recul de an parait largement suffisant pour valuer la consolidation La classification propos e par le G E S T O a t utilis e mais l gerement modifi e car elle s av re l usage imparfaite pour la traumatologie L valuation sans crit re d exclusion a t r ali s e suivant la norme E N 540 Fractures 10 taient ouvertes et 60 ferm es La localisation tait diaphysaire en os cortical dans 25 cas piphysaire dans 32 observations et m taphysaire 8 fois Dans 9 cas la fracture si geait sur un os court 70 cas ont t class s T2 et 4 T3 Par ailleurs 54 cas rentrent dans la cat gorie D et 20 dans la cat gorie D Seulement 3 autogreffes ont t associ es la c ramique alors que les fractures taient en g n ral complexes Pseudarthroses 14 taient diaphysaires 10 piphysaires et 2 m taphysaires 4 si geaient sur un os court Dans 7 cas une autogreffe et dans cas une allogreffe ont t associ es la
45. ng biomaterials In the manufacturing process of every ceramic material three main stages arc noceasary for their elaboration Initially the material is in a powder form subsequently the powdered material is suspended in a solution and shaped at room temperature imo the specific part In the third stage the part is sintered to obtain fusion of the gran of the materal and to elumimate the internal microporosity During this process the physical and chemical characteristics of the material can change The characteristics of the final calcium phos phate material including its chemical composi tion can vary widely This depends only partly on the composition of the initial powder Non stoichiometric HAs are relatively unstable and around 900 C some other phases tricalcium phosphate calcium oxide can appear 23 Even perfectly stoichiometric HA may give rise to an oxyhydroxyapatite at temperatures over 1000 C or to tricalcium phosphate and tetracalcium phosphate above 1570 C Analysis of commercially available calemm Phosphates for bone substitution showed that the chemical composition of the material dif fered from that of a supposedly pure HA NR Unpublished data 1992 A variable amount of tncalcium phosphate phase B TCP was found in most of the specimens analyzed To evaluate the influence of this phase on the osscointegra tion of calcium phosphates and particularly HA we implanted calcium HA ceramics differing da
46. nte para asegurar la consolidaci n de una fractura diafisaria compleja la estabilidad de la osteosintesis es fundamental Un caso muy reciente para esta recopilaci n confirma esta reserva una osteosintesis inestable del humero a evolucionado hacia la rotura del implante a pesar de la presencia del TCH Reintervenciones de pr tesis Se han presentado siempre hasta ahora buenos resultados pero la perspectiva en este caso es aun insuficiente Artrodesis La consolidaci n ha sido confirmada en 9 casos sobre 11 1 caso se ha perdido de vista y una artrodesis del escafoides con el semilunar a evolucionado hacia una speudoartrosis dura 3 2 resultados radiologicos en emplazamientos esponjosos Desde el primer mes se nota una lisis perif rica de la cer mica Esta alteraci n en estrellas es particularmente visible en los elementos alejados Al cabo de 2 o 3 meses los granos parecen integrarse en un tejido travecular asegurando la KASIOS Mai 2003 15 continuidad de las traveculas seas del hueso esponjoso vecino El conjunto se densifica al cabo de 6 meses El resto de los gr nulos radioopacos es totalmente integrado al hueso esponjoso En emplazamiento cortico medular Los granos se encuentran atrapados en el callo cortical y medular participando de esta manera a la formaci n de un puente que reune las extremidades de la fractura Lo que queda de los gr nulos es aun visible al cabo de 3 afos por la densificaci n d
47. o de 17 meses KASIOS Mai 2003 32 TCH Publicaciones Oremora ti s N ENa nona ENDON RBAY A M ST ADPTEMATE IPE VEN 1 NO 4 EFFECTS OF THE CHEMICAL COMPOSITION OF CALCIUM PHOSPHATE CERAMICS ON THEIR OSSEOINTEGRATION sos P Frayssinet MD PhD JL Trouillet DVM N Rouquet PAD FE Azimus DVM A Autefage DVM ABSTRACT Calcium phosphate macroporous ceramics have been shown to be n biocompatible material for bene surgery however heir osseointegration is sometimes very poor To measure the effect of the calcium phosphate composition of the ceramic an its osseointegration macroporons ceramics of var ying chemical composition were implanted in sheep femurs All other characteristics were the same Results were evaluated histologically using image analysis and slowed significant dillerences in the amount of bone formed at the contact of the different ceramics H s t prouv que les c ramiques macro poreuses de phosphate de calcium sont des elements bio compatibles utilizables en chirur gie osseuse bien que leur ostcocimtegratim sant parfois tres mediocre lour appr cier le reten tissement sur l ost o integration de la presence du phosphate de calcium dans les c ramiques des c ramiques mactoporenuses de composition chimique variable furent implant es sur des f murs de mouton toutes les autre oar act ristiques tant semblables par ailleurs Les r sultats furent valu s histologlque
48. o kinds of B TCP containing specimens after 2 different specimens of B TCP containing implan months of implantation The pure HA specimens Table KASIOS Mai 2003 37 ORTHOPADICS INTERNAT Fig 8 Back scatter SEM mi crophotograph of dissolving arcas E of a TCP contain ing specimen implanted for 2 months A less dense zone where grain boundaries are dissolved is seen facing the salt tissue silver methenamine Fig 9 A p TCP containing spec imen implanted for 4 months showing the osseointegration of the specimen S in the cortical bone B fuchsin toluidine blue x 200 Enimie WWA After a 4 momh implantation period the TCP containing implants were completely osseoimegrated in the cortical region The pores of the ceramics were filled with haversian bone Fig 9 However thei medullary part was surrounded by layers of lamellar bone The quantity of bone found at the medullary level seemed to have decreased greatly SEM micro photographs of an anorganic preparation of B TCP containing unplans showed calcified bone matrix costing the ceramic On high mag nification SEM tmicrophotographs the bonc matrix was clearly distinguishable from the ceramic and bone was attached by some focal ized point of contact to the ceramic Fig 101 The amount of bonc at the point of contact with the material in the medullary zone seemed 10 Ix less than in the TCP containing implants studied at 2 months Pu
49. pure HA N Rouquet unpublished data A variable amount of tricalcium phosphate 8 TCP phase was found in most of the specimens analysed To evaluate the influence of this phase on the osseointegration of calcium phos phates we implanted calcium HA ceramics differing Correspondance to De P Frayanicet lt 1983 Dutierworin Mememann Loo 0142 94 12 93 080423 07 only in the amount of A TCP In the material into sheep Implants were then histologically analysed after different periods of implantation MATERIALS AND METHODS Macroporous calcium phosphate ceramics Pure HA powder Bioland France was obtained by a double decomposition method Pure 6 TCP powder Hioland France was blended with HA powder to obtain two different powder mixtures containing 75 HA 25 B TCP and 50 HA 50 I TCP respectively The macroporous specimens were manufactured according to clussical processes A slurry mode from the different powders water and additives was prepared This solution was then manipulated to obtain an initial ceramic shape The final sintering stage gave a 100 crystalline calcium phosphate material Using this technique cylinders with a diameter of 0 0 cm and a length of 1cm were made A porosity consisting of interconnecting macropores from 400 up to 1500 ym was produced The resulting porosity was 70 Three types of implants were made each having a different calcium phosphate phase composition Their TCP HA ratio was 0
50. ramente rellenada KASIOS Mai 2003 8 P 1b detalle OI hueso inmaduro neoformado OA hueso primitivo de tipo esponjoso C cer mica La colonizaci n se hace por invasi n de los tejidos y de los vasos partiendo del tejido seo del paciente en ausencia de cer mica o de contacto oseo cer mico no se produce formaci n sea imagen n 2 Imagen n 2 Al cabo de 6 semanas cavidad no rellenada por la cer mica La parte ocupada por el hueso no es importante KASIOS Mai 2003 9 El hueso nuevo se forma por aposici n directamente en la superficie de la cer mica sin interposici n fibrosa Los osteoblastos se diferencian a partir de los fibroblastos del tejido conjuntivo Al cabo de 6 semanas el hueso neoformado es de tipo inmaduro como lo indica la talla de las lagunas osteocytarias 2 Osteointegraci n Al cabo de 12 semanas el implante esta totalmente recubierto por el tejido seo en toda su superficie sin interposici n fibrosa Imagen n 3 Osteointegraci n del lugar esponjoso al cabo de 12 semanas Los macroporos est n totalmente colmados por el hueso modificandose en aposici n con la superficie de la cer mica Fragmentos de cer mica desprendidos y igualmente integrados KASIOS Mai 2003 10 Principio de la resorci n fragmentaci n de la cer mica y reconstrucci n sea imagen n 4 E Imagen n 4 Osteointegraci n y reconstrucci n en la cortical sea cabo de 12 sem
51. re HA implants were situated in a dense connective environment both in the medullury zone and the cortical region and showed no sign of osscointegration DISCUSSION Calcium phosphate ceramics are known as a particularly osseocompatible biomaterial How ever the osseoimegration of this material is not always very good PE Unpublished data 1992 We have previously analyzed histologically some apatitic materials implanted in humans and included in a fibrous tissue Other failures JULY ALGUSTSEPTEMBER 1993 VOL ENO 4 Fig 10 SEM microphotograph of an anorganic preparation of the medullary zone of a 50 P 1CP 50 HA specimen implanted for 4 months The bone calcified matrix M is coating 100 jum the ceramic El Bar of the osscoinicgrution of calcium phosphates can be found in the literature H is very difficult to find common cause of all these failures The diversity of the specifications of the calcium phosphates implanted did not make it possible to link the biological result obtained t a particular characteristic of the material Osscoimegration of the calcium phosphate ceramics has been proved to depend on the pore size and the chemical composition of the ce ramic However results published on the influence of the chemical composition of the ceramics are a little confusing because the tested specimens were composed of a mixture of several phases If the HA is considered as the calcium phosphate phase clos
52. rnent par analyse d image et ont montre des differences From Brotand fec and the Ecole Natumale Va rimaine de Towloue Toulouse France Presented at the 14th International Nveposimm of the Center far laplant Surgery Anai Zion Medical Center howards the 213 Century he rikaa da Horizon April 29 30 4992 Matha bawel fhe ameles from this cympouum were compiled and prepared for ORTHOPAEDICS International Edition by Fechiel Gathered MD MS and David G Morales MD FACS Reprint requests Or P Fravisinet Hilal fire 52 Rte d Espagne 11700 Toulouse Franc Menificatives quant la quantit d as forme au contact des dillerentes ceramiques Iraniduted fis Mateus PHoreus MI kheramikMaterialienaus makroporesem Calcium l hosphat erwiesen sich als biokompatibel f r dic hnochenchirurgle Hingegen ist deren Osteointe gration manchmal schlecht Um den FE ffeki der Calcium Ilosphat Zusanancrsctaong der her amik auf deren Osteaintegration zu messen wir den makcopocose Keramiken verschiedener chemischer Zusammensetzung thri gleichhleihien den anderen Charakteristiken in Schaf Femara eingesetzt Die Ergebnisse wurden histoloyis li mittels Bild Analsse ausge werlet Es zeigten sich signifikant unterschiedliche Mengen von Kocher culsldonzgen im Kontakt zu den verschiedenen Krramiben Pranviatod bx Najla P rotes 1119 Se ha demostrado que las ceramicas de fosfato de calcio macroperesies son materiales compatibles con la cirugia
53. rosa I Los otros fragmentos reducidos a peque as part culas se encuentran en las lagunas seas asociadas con particulas seas de taladro El an lisis del extracci n pone en evidencia las capacidades de la osteoconduccion del TCH que queda integralmente colonizado por el tejido seo la correcta osteointegracion del material realizada en ausencia de interposici n fibrosa o de reacci n inflamatoria al cuerpo extranjero la desaparici n progresiva de la cer mica KASIOS Mai 2003 31 Condroma del dedo medio izquierdo MEY 04 93 Relleno de la cavidad por TCH despu s de legrado Relleno completo pero insuficiente en la parte distal del hueso Resultado radioldgico en postoperatorio fotografia al cabo de 1 mes al cabo de 2 meses al cabo de 5 meses al cabo de 10 meses al cabo de 17 meses fotografia A los 5 meses se observa una alteraci n perif rica en estrella de los granos que se encuentran integrados en una masa por traveculaci n La laguna distal permanece Entre 10 y 17 meses intervienen pocos cambios Se observa una fusi n diafisaria entre la cortical y la masa iniciada por los injertos La osificaci n se hace progresivamente hacia la laguna distal Traveculas seas correctamente orientadas salen de los gr nulos en direcci n de las ep fisis y en continuidad con las traveculas de la esponjosa epifisaria Radiograf a postoperatoria Radiograf a al cab
54. rrounding the material Osteoblasts O are located at the surface of a bone trabecula Silver methenamine Figure 11 Back scatter electron microscopy of a fragment of an HA TCP ceramic 7596 2596 implanted for 2 months The outside perimeters arrows of the fragments F are less dense than the bulk material B Bone The percentage of the implant surface in contact with bone varied greatly according to the chemical composition of the material After 2 months of implantation pure HA implants had only a small percentage of their surface at the contact of bone tissue Figure 6 Implants containing B TCP had much more bone tissue fixed at their surface The percentage of the surface at the bone contact point increased greatly when B TCP was present in the chemical composition of the material However there was no significant difference in the thickness or in the amount of bone trabeculae adsorbed for the two groups of implants containing S TCP After a 4 month implantation Figure 6 the implants containing TCP were completely osseointegrated in the cortical region The pores of the ceramics were filled with Haversian bone Figure 12 However their medullary part was surrounded by thin layers of lamellar bone The quantity of bone found at the medullary level seemed to have decreased greatly SEM microphotographs of an anorganic preparation of implants containing 8 TCP showed a coating of the ceramic with calcified bone matrix On S
55. rticle general sur les substituts osseux OSTEOCONDUCTION La c ramique biphas e de phos phates de calcium est fortement ost oconductrice sa surface sert de support unc colonisa ton osseuse miemse Abs pieux lorsque de d fect est cor inaimes en site spon rectement comble on observe unc ncolormalion osseuse progression compete qui tapis ext ncur des granules et at emi par ics naeropores centre du trou fig n l La vitesse de La progression os dre de OS c ex donc de Vo mm par semaine doivent Les macroporcs avoir une taille suffisante et tre in terconnect s alin de permettre celle penetration le tro cra ique persis Par comparaison non combl par la lt Figure 1 Outeocandwe A ta Vue d uk b De RISE ORTHOPEDIQUE te On note seulement une dis cr te n olonmation osscuse la surface des berges La colonisation se fait par inva ston vasculaire ct tissulaire de Vimplant partir du tissu os eux receveur En l absence de c ramique o cn l absence de contact os c ramique ln y a pas de formation osscuse L os nouveau se forme en appo sition directement la surface de La c ramique sans interpos breusc 1 ton d tcoblastes se diff rencient partir des fi Ab e tissu n otforine ex broblastes du conjonctif SCAT de Vos immature comme en t moigne la taille des lacunes os tcov taimes fi
56. ry zone The implant in the cortical zone has been degraded Fuchsin toluidin Figure21 High magnification of a resorbing cortical zone showing the degradation of the material C by osteoclasts O and macrophages Fuchsin toluidin composition of the ceramic However results published on the influence of the chemical composition of the ceramics are a little confusing as the tested specimens were composed of a mixture of several phases If the HA is considered as the calcium phase closest to the bone mineral phase other calcium phosphate phases can be used in the composition of orthopaedic biomaterials The two most frequently used phases are TCP and HA Some of their physico chemical properties are different The solubility of 8 TCP at the physiological pH is greater than the solubility of the HA This property could interfere with the ossification process at the point of contact of the implant The calcium being secondary messenger for cells TCP could interfere with cell differentiation at its point of contact Moreover the supersaturation of the extracellular medium for calcium and phosphate around the implant could be Increased making the collagen mineralization easier We could not find a greater material resorption for the B TCP containing implant in this study Implants con taining both pure HA and TCP showed strong marks of cellular degradation However the degradation of implants containing J TCP shows th
57. s pierden individualidad y fusionan en una masa Se produce una aglomeraci n entre la masa del material de sustituci n y la cortical en el lugar de la fractura Al cabo de 13 meses Radiografia postoperatoria Al cabo de 25 meses despu s de consolidaci n y ablaci n del material la fusi n muy clara se ha producido entre el sustituto seo y la cortical que se encuentra reforzada en el sitio de la fractura Traveculas oseas correctamente orientadas unen la masa del sustituto seo y la esponjosa vecina KASIOS Mai 2003 22 Al cabo de 25 meses despu s de la ablacion del material KASIOS Mai 2003 23 Fractura compleja articular de la extremidad inferior del radio con perdida de sustancia esponjosa DUB 09 94 Abordaje anterior Abertura del canal carpiano y osteosintesis del radio por placa Maconor 2 epifisaria broche relleno de la perdida de sustancia por TCH Radiografia preoperatoria Control al cabo de 40 dias KASIOS Mai 2003 Control al cabo de 5 meses despu s de la ablaci n del material de osteosintesis Perfil De Frente KASIOS Mai 2003 25 Artodesis bajo astragalo SIN 01 94 Osteosintesis por tornillo Relleno por TCH del sinus del tarso avivado Resultado clinico consolidaci n normal muy bueno al cabo de un a o Resultado radiol gico al cabo de 21 meses fotograf a despu s de ablaci n de los tornillos Al cabo de 21 meses los gr nulos de TCH ya no ap
58. taining the implanted material The specimens were first fixed in 5 buffered form aldehyde then dehydrated in alcohol and embedded in poly methy methacrylate One section of each implant parallel to its long axis was made using a cooled low speed diamond saw Cuto 1 Reicher France The sections were polished on a Lam Plan MM823 polisher with silicon carbide discs LP P80 P120 P240 P600 P1200 lubricated with water then P410 lubricated with a Ti grade lubricant to obtain a 50 ym thick section They were surface stained with either fuchsin toluidine blue or silver methenamine then observed with a light microscope P Frayssinet unpublished data Some sections stained with silver methenamine were carbon coated then examined by back scatter scanning electron microscopy SEM on an ISI SS60 operated at 25 kV P Frayssinet unpublished data One specimen of each chemical composition implanted for 4 months was oxidized with a 5 sodium hyposulphite solution These anorganic specimens were then observed with a scanning electron microscope Jeol JST 200 operated at 25 kV Image analysis was performed on sections of material Four zones were chosen at random on both the cortical and medullary zones of each section at a X20 magnifi cation They were analysed by a photometric system of image analysis Biocom 200 1 5 The polygonal outlines of implants and hone tissue were created by thresholding The lengths of the implant and bon
59. tion occurring in the pores of the different ceramics takes place after a connective tissue ingrowth inside the ceramic This so called bone ingrowth is not really an ingrowth of bone tissue inside the material but rather a differentiation of the connective tissue which invaded the material in the first bone healing stage This differentiation is done according to the different stages of the medullary healing process The degradation of artificial ceramics began earlier than the degradation of the natural sintered bone during the first month of implantation The organism could make the difference between the synthetic material and the control material The cells degrading the implanted material were morphologically different for the sintered bone and for the ceramics Osteoclast like cells degraded the sintered bone while the ceramic was degraded by macrophages osteoclast like cells and giant cells CONCLUSION The presence of various calcium phosphate phases in a bioceramic does not influence only the physico chemical properties of the material In this study the addition of B TCP to the HA seemed to increase the solubility of the ceramic containing TCP and dramatically increased the bone ingrowth in the ceramic pores The so called bioactivity of calcium phosphate bioceramics depends to large extent on their calcium phosphate phase content The interaction between calcium phosphate products and cells could be much more complex th
60. toriamente desechado Uso nico solamente Np volver a esterilizar Referencias bibliogr ficas x Frayssinet y col Osteointegration of macroporous calcium phosphate ceramics having a different chemical composition Biomaterials 1993 Vol 14 N 6 Trecant y col Influence of post implantation phyco chemical changes in a macroporous ceramic on its mechanical strength Journal of Materials Materials in Medecine 7 1996 p 227 229 KASIOS Mai 2003 7 Experimentacion animal Protocolo Las implantaciones han sido realizadas en el cordero Unas cavidades cilindricas de 6 milimetros de diametro han sido realizadas en diferentes partes oseas corticales o esponjosas que han sido rellenadas por granulos del TCH Tomas histol gicas realizadas despu s de 6 a 12 semanas son comparadas con la evoluci n de las cavidades id nticas no colmadas Resultados 1 Osteoconduccion El TCH es sumamente osteoconductor cuando el implante se encuentra en el hueso una colonizaci n sea intensa tiene lugar en su superficie Al cabo de 6 semanas en la esponjosa cuando el orificio ha sido bien llenado se puede observar una neoformaci n sea con progresi n centr peta recubriendo la cer mica y alcanzando los macroporos interconectados en el centro de la cavidad imagen n 1 Imagen n 1 osteoconducci n al cabo de 6 semanas 1a vista global La neoformaci n sea alcanza la parte central de la cavidad que esta ente

Características del TCH

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Caracter&iacute;sticas del TCH

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Características del TCH