EP0758218A1 - Knee prosthesis with a movable meniscus - Google Patents

Knee prosthesis with a movable meniscus

Info

Publication number
EP0758218A1
EP0758218A1 EP95918045A EP95918045A EP0758218A1 EP 0758218 A1 EP0758218 A1 EP 0758218A1 EP 95918045 A EP95918045 A EP 95918045A EP 95918045 A EP95918045 A EP 95918045A EP 0758218 A1 EP0758218 A1 EP 0758218A1
Authority
EP
European Patent Office
Prior art keywords
bearing surface
component
meniscal
tibial component
knee prosthesis
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP95918045A
Other languages
German (de)
French (fr)
Inventor
Gérard YSEBAERT
Franck Herrault
Benoít DROILLARD
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
YSEBAERT SA
Original Assignee
YSEBAERT SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by YSEBAERT SA filed Critical YSEBAERT SA
Publication of EP0758218A1 publication Critical patent/EP0758218A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/38—Joints for elbows or knees
    • A61F2/3868—Joints for elbows or knees with sliding tibial bearing

Definitions

  • the present invention relates to a movable meniscus knee prosthesis.
  • Such prostheses are used to replace, during a surgical operation, natural cartilages presenting deficiencies due to an illness or a trauma.
  • the prosthesis called "OXFORD" described for example in French patent n ° 2290883 comprises a tibial platform having a flat surface on which a meniscal part is movable in translation.
  • Such a prosthesis is not entirely satisfactory, due to the excessive stresses undergone by the meniscal part, usually made of plastic. Indeed, the edges of the cavity, of section greater than the section of the mushroom-shaped projecting part extending to the upper surface of the tibial platform, strike said projecting part. Due to the large forces exerted on a knee prosthesis, these repeated shocks lead to rapid deterioration of the meniscal part.
  • European patent n ° 0021.421 describes a prosthesis whose tibial platform has two curved guide grooves cooperating with the lower surface of two movable menisci having a projecting part whose section is in the shape of a tail. dovetails.
  • British patent 1534263 describes such a prosthesis comprising a linear guide groove allowing a constrained movement of a meniscal part.
  • French patent FR2685632 describes a prosthetic assembly comprising: a first type of femoral element able to cooperate either with a movable plate of a tibial base to constitute a knee prosthesis with movable plate, either with a fixed plate of a tibial base to constitute a knee prosthesis with fixed plate with conservation of the posterior cruciate ligaments.
  • a second type of femoral element capable of cooperating with a fixed plate of the tibial base, to constitute a posterior stabilized knee prosthesis with fixed plate.
  • Another French patent FR2692476 describes a total knee prosthesis of the sliding type, comprising a femoral element whose condylar pads cooperate in abutment on a plate of a tibial element.
  • the tibial and femoral elements have, in combination, complementary stop and guide means which are adjustable and removable, capable of ensuring the stabilization of the two elements while respecting the ligament iso when the anterior ligament or the two cruciate ligaments are destroyed.
  • complementary stop and guide means which are adjustable and removable
  • a total knee prosthesis of the sliding type comprising a bi-condylar femoral part, the profiled external face of which comes into contact, support and centering on an intermediate element of high-density polyethylene, said intermediate element being positioned and fixed on the upper face forming a metal base of the 'tibial element, and in that the upper part of the tibial part is arranged with a plurality of positioning openings relative to the intermediate part, the latter comprising two centering pads to engage in positioning openings thus allowing an adjustment in position of the intermediate plate relative to one tibial element.
  • European patent EP183670 describes an artificial meniscus-tibia joint for a knee joint prosthesis comprising at least one tibial component on which the meniscus is disposed so as to be able to move or be mobile.
  • the meniscus has a largely planar sliding surface against the tibial component, the meniscus or the tibial component having directional control members giving the meniscus the ability to move in all directions along the tibial component, but these members direction control elements being also arranged so as to limit the amplitude of the movement.
  • the object of the invention is to remedy this drawback by proposing a prosthesis allowing an additional degree of freedom, and thus making it possible to avoid blocking of the joint during certain movements of the knee.
  • the invention relates more particularly to a knee prosthesis composed of: a) at least one tibial component having a first bearing surface,
  • a femoral component having a fourth bearing surface which comes into sliding contact with the third bearing surface of the meniscal component
  • the tibial component is provided with at least one cavity into which penetrates at least a portion projecting from the second bearing surface of a meniscal component, the cavity and the protruding portion being shaped so as to allow lateral movements and rotational movements of at least one meniscal component relative to the component tibial, the rotational movements taking place along at least one axis substantially perpendicular to the first bearing surface and eccentric laterally with respect to the tibia.
  • the prosthesis according to the invention has a possibility of rotation relative to a virtual axis offset laterally outside the tibial platform.
  • the center of rotation can be moved to a point whose projection on the plane perpendicular to the axis of the tibia is outside the prosthesis.
  • the meniscal component is movable in rotation along an axis corresponding to the axis of the tibia.
  • Such a prosthesis is not entirely adapted to an anatomical movement, and therefore leads to an unsightly gait.
  • the prosthesis according to the present invention makes it possible to better reproduce the natural movement of flexion or extension of the knee. We can consider several different realizations.
  • the prosthesis according to the invention comprises two meniscal components each having a part projecting from the second surface and in that the tibial component (1) has two cavities capable of cooperating each with the projecting part of one of the meniscal components.
  • the cavities are closed by a continuous rim.
  • the edges have a constant thickness over an extension of a half-circumference of the cavities where they border the tibia element.
  • the rim is located to limit the pivoting rotations of the meniscus in angular strokes at most equal to the natural strokes.
  • the knee prosthesis according to the invention comprises:
  • a meniscal component having a second bearing surface which comes into sliding contact with the first bearing surface of the tibial component to undergo a sliding movement relative to the latter during the movement of the joint, the meniscal component having a third bearing surface
  • a femoral component having a fourth bearing surface which comes into sliding contact with the third bearing surface of the meniscal component characterized in that the meniscal component consists of a single piece, in that the first bearing surface of the tibial component is in the form of a bean, and in that the second bearing surface of the meniscal component is also in the form of bean of smaller dimension in the antero-posterior direction the shape of said first and second bearing surfaces being complementary and determined so as to allow a movement limited in rotation and in linear movement of the meniscal component with respect to the tibial component.
  • the tibial component has a bearing surface formed by two lateral zones, each being delimited externally by a rounded convex edge, and internally by a rounded convex edge extending from the front of the tibial plateau to a transverse axis. substantially median, the two lateral zones being joined by a central zone delimited at the front by a concave curved edge extending at each of its ends one of the interior edges, and at the rear by an edge extending at each of its ends one of the outer edges.
  • the tibial component has a planar bearing surface delimited on its periphery by a projecting edge, the meniscal component having a bearing surface capable of cooperating with the bearing surface of the tibial component so as to allow limited translational and rotational movements.
  • the meniscal component has a bearing surface formed by two lateral zones, each being delimited externally by a rounded convex edge, and internally by a rounded convex edge extending from the front of the tibial plateau to to a substantially median transverse axis, the two lateral zones being joined by a central zone delimited at the front by a concave curved edge extending at each of its ends one of the interior edges, and at the rear by an edge extending to each of its ends one of the outer edges.
  • the bearing surface of the meniscal component constitutes a flat projecting surface.
  • FIG. 1 top view of the tibial component and the meniscal component in the posterior position
  • FIG. 2 shows a view of the tibial component and the meniscal component along a section plane AA ';
  • FIG. 3 shows a view of the tibial component and the meniscal component along a section plane BB ';
  • FIGs 4 to 8 show top views of the tibial component and the meniscal component in different relative positions.
  • FIG. 9 shows a view of an alternative embodiment with two independent meniscal components
  • - Figures 10 to 14 show the movements of the meniscal components relative to the tibial component
  • FIG. 15 shows a view of another alternative embodiment with two independent meniscal components.
  • FIG. 1 represents a top view of the tibial component (1) provided with the meniscal component (2).
  • the tibial component is symmetrical with respect to a median plane BB '.
  • the tibial component (1) is fixed to the tibia in a known manner and visible in FIGS. 2 and 3, by one or more points (3, 4) grooved or covered with a biocompatible material intended to penetrate into the spongy tissue.
  • the dimensions of the tibial component are within a rectangle of approximately 80 x 55 millimeters.
  • the dimensions of the meniscal component are within a rectangle of approximately 60 x 30 millimeters.
  • the upper surface (5) of the tibial component has a bean-shaped zone (6) symmetrical with respect to the median anteroposterior axis BB '.
  • the tibial component (1) as well as the meniscal component (2) have notches (7) U-shaped so to clear an opening (5) for the passage of the cruciate ligaments.
  • the upper surface (8, 9) is complementary with the contact surface of the femoral component fixed on the femoral bone in a known manner.
  • the bean-shaped zone (6) has two lateral zones (11, 12) joined by a central zone (13).
  • a projecting rim (14) having a dovetail profile, with a lower edge (15) surmounted by an upper edge (16) extending inwardly of the contact zone between the heel ( 17) of the meniscal component and the planar contact surface (28) of the tibial component.
  • the heel (17) has a complementary peripheral edge.
  • the two lateral zones (11, 12) are symmetrical with respect to the anteroposterior axis BB '.
  • the lateral zone (11) will be described below in more detail, it being understood that the second lateral zone (12) has the same characteristics.
  • the lateral zone (11) has a generally oval shape, with a semicircular front edge (18) extended externally by a rounded external edge (19) extending generally parallel to the anteroposterior axis BB ', and extended on the rear edge by an edge (20) substantially forming a quarter of a circle.
  • the front edge (18) of semi-circular shape is extended by a rounded inner edge (19) extending generally parallel to the anteroposterior axis BB 'and along the notch (7).
  • the two lateral zones (11, 12) are joined on the front side by an edge (21) in the form of a concave semicircle, seen from the support zone (6), and on the rear side by an edge (22 ) extending along a general axis perpendicular to the 'BB' axis, convexly seen from the inside of the support zone (6).
  • the meniscal component (2) has a heel (18) whose general shape is equivalent to that of the area support (6) of the tibial component (1), but whose dimensions and curvatures are different to allow limited mobility in rotation and in translation, as shown in Figures 4 to 8.
  • Figure 4 shows an example of displacement in rotation relative to the center of the prosthesis.
  • One of the rounded lateral branches (25) of the meniscal heel (17) comes to the front edge (18) of the corresponding lateral zone (11).
  • the concave central part (26) rocks laterally, on the side of this lateral zone (11).
  • the opposite lateral branch (27) recedes against the rear edge (29) of the lateral zone (12).
  • FIG. 5 represents another mode of displacement, according to which the posterior concave edge (30) of the meniscal heel (17) bears against the concave anterior edge (21) of the tibial component.
  • the two components can thus move in a rotation corresponding to the development of the curvatures of the two front edges (21, 30).
  • Figures 6 and 7 show modes of displacement in translation parallel to the postero-anterior axis BB '.
  • FIG. 8 represents a combined displacement of translation and rotation.
  • FIG. 9 shows a view of an alternative embodiment with two independent meniscal components.
  • the tibial component (1) is a flat platform having a first contact surface (5) provided with two oblong cavities (30, 31) with a substantially flat bottom, of shallow and constant depth. These cavities (30, 31) allowing the displacement in translation and in rotation of two complementary projecting studs (33, 34) each secured to one of the meniscal components (35, 36).
  • the protruding studs (33, 34) have a low and constant thickness for engagement in the oblong cavities (30, 31) and to allow a sliding movement in rotation and in translation, within limits defined by flanges (37, 38).
  • the cavities (30, 31) have uneven surfaces and are placed so that the pins (33, 34) both abut against the rear ends of the cavities (30, 31) in the leg extension position shown in FIG. 10 and against the front ends of these two cavities in the maximum bending position illustrated in FIG. 11.
  • the straight lines coming from the centers of the studs (33, 34) in these two positions intersect at a point 0 which constitutes a pivot center of the joint and which is almost immobile during the movement of the studs (33, 34).
  • the cavities (30, 31) are however wider than the tenons (33, 34) so that slightly different movements are authorized and that greater flexibility of the joint is obtained.
  • the cavities (30, 31) are surrounded by continuous flanges having a main part (37, 38) of constant width and extending over a little more than half the circumference of the cavities (30, 31).
  • (37, 38) is chosen so that the pressure of the meniscal components (37, 38) never becomes excessive. It is three millimeters in an embodiment where the parts are made of high density polyethylene for the load-bearing parts, undergoing friction and contact pressure, and of stainless steel, of cobalt-based alloy or of titanium alloy for the rest .
  • FIG. 12 shows a slightly different embodiment of a prosthesis according to this variant.
  • the tibial component (1) has two similar and symmetrical cavities (40, 41) with a width of the order of 26 millimeters and a length of 39 millimeters for circular tenons (42) with a diameter of 23 millimeters, and not oblong as in the previous embodiment example.
  • a state of extension illustrated in FIG. 12 we will obtain, from a state of extension illustrated in FIG. 12, and similar to that of FIG. 10, a state of bending represented either at Figure 13, or Figure 14.
  • One of the tenons (42) reaches the end of the cavity into which it enters, while the other tenon stops approximately in the center of the other cavity.
  • FIG. 15 represents a slightly modified design, the purpose of which is similar to that of FIG. 12, that is to say that the tibial component (53) is designed to be used indifferently for right and left knees.
  • the tibial component (53) has two similar straight and parallel grooves (56).
  • the meniscal component (54) formed of two elements (58, 59) each associated with a groove (56) by circular studs (57). Sufficient lateral play is provided to allow rotations of the joint in both directions.

Abstract

A knee prosthesis consisting of (a) at least one shin bone component (1) with a first bearing surface; (b) at least one meniscus component (2) with a second bearing surface slidably engageable with the first bearing surface on the shin bone component (1) for sliding motion relative thereto during movement of the joint, said meniscus component (2) having a third bearing surface; and (c) a thigh bone component with a fourth bearing surface slidably engageable with the third bearing surface on said meniscus component (2), wherein the shin bone component (1) is provided with at least one cavity engaged by at least one projection on the second bearing surface on the meniscus component (2), said cavity and said projection being shaped to enable sideways and rotational motion of at least one meniscus component relative to the shin bone component, which rotational motion occurs about an axis substantially perpendicular to the first bearing surface and is offset sideways relative to the shin bone.

Description

PROTHESE DU GENOU A MENISQUE MOBILE . KNEE PROSTHESIS WITH MOBILE MENISCUS.
La présente invention concerne une prothèse du genou à ménisque mobile .The present invention relates to a movable meniscus knee prosthesis.
De telles prothèses sont utilisées pour remplacer , au cours d ' une opération chirurgicale , des cartilages naturels présentant des déficiences dues à une maladie ou à un traumatisme .Such prostheses are used to replace, during a surgical operation, natural cartilages presenting deficiencies due to an illness or a trauma.
On connaît dans l ' art antérieur plusieurs prothèses à ménisque mobile . La prothèse dite "d ' OXFORD" décrite par exemple dans le brevet français n° 2290883 comporte une plate-forme tibiale présentant une surface plane sur laquelle une pièce méniscale est mobile en translation . Une partie saillante en forme de champignon , coopérant avec une cavité prévue dans la partie inférieure de la pièce méniscale permet de le limiter par rapport à la plate-forme tibiale .Several mobile meniscus prostheses are known in the prior art. The prosthesis called "OXFORD" described for example in French patent n ° 2290883 comprises a tibial platform having a flat surface on which a meniscal part is movable in translation. A mushroom-shaped protruding part, cooperating with a cavity provided in the lower part of the meniscal part, makes it possible to limit it relative to the tibial platform.
Une telle prothèse n ' est pas totalement satisfaisante , en raison des contraintes excessives subies par la pièce méniscale, habituellement en matière plastique. En effet, les bords de la cavité, de section supérieure à la section de la partie saillante en forme de champignon s ' étendant à la surface supérieure de la plate- forme tibiale , viennent heurter ladite partie saillante . En raison des forces importantes qui s ' exercent sur une prothèse du genou, ces chocs répétés aboutissent à une détérioration rapide de la pièce méniscale .Such a prosthesis is not entirely satisfactory, due to the excessive stresses undergone by the meniscal part, usually made of plastic. Indeed, the edges of the cavity, of section greater than the section of the mushroom-shaped projecting part extending to the upper surface of the tibial platform, strike said projecting part. Due to the large forces exerted on a knee prosthesis, these repeated shocks lead to rapid deterioration of the meniscal part.
Pour éviter une telle détérioration, le brevet européen n° 0021.421 décrit une prothèse dont la plate-forme tibiale présente deux sillons de guidage incurvés coopérant avec la surface inférieure de deux ménisques mobiles présentant une partie saillante dont la section est en forme de queue d ' aronde .To avoid such deterioration, European patent n ° 0021.421 describes a prosthesis whose tibial platform has two curved guide grooves cooperating with the lower surface of two movable menisci having a projecting part whose section is in the shape of a tail. dovetails.
Cet te pro thèse commerc ial i sée sous la dénomination LCS , est destinée au remplacement chirurgical d ' un genou fonctionnellement lésé et permet de reproduire f idèlement les di f f érents degrés de l iberté de l'articulation du genou, et d'améliorer le confort du patient équipé d'une telle prothèse.This commercial pro te thesis, under the name LCS, is intended for the surgical replacement of a functionally injured knee and makes it possible to faithfully reproduce the different degrees of freedom from the knee joint, and to improve the comfort of the patient fitted with such a prosthesis.
Ces prothèses présentent l'inconvénient d'une faible surface d'appui des ménisques sur la plate-forme tibiale. Les efforts importants, pouvant atteindre dix fois le poids de la personne sur laquelle la prothèse a été implantée sont répartis sur une surface faible et conduisent de ce fait à une dégradation des ménisques.These prostheses have the disadvantage of a small bearing surface of the menisci on the tibial platform. The significant efforts, which can reach ten times the weight of the person on whom the prosthesis was implanted, are distributed over a small area and therefore lead to a deterioration of the menisci.
Le brevet anglais 1534263 décrit une telle prothèse comportant une rainure de guidage linéaire permettant un déplacement contraint d'une pièce méniscale.British patent 1534263 describes such a prosthesis comprising a linear guide groove allowing a constrained movement of a meniscal part.
Un autre document de l'art antérieur, le brevet français FR2685632 décrit un ensemble prothétique comprennent : - un premier type d'élément fémoral apte à coopérer soit avec un plateau mobile d'une embase tibiale pour constituer une prothèse du genou à plateau mobile, soit avec un plateau fixe d'une embase tibiale pour constituer une prothèse du genou à plateau fixe avec conservation des ligaments croises postérieurs.Another document of the prior art, French patent FR2685632 describes a prosthetic assembly comprising: a first type of femoral element able to cooperate either with a movable plate of a tibial base to constitute a knee prosthesis with movable plate, either with a fixed plate of a tibial base to constitute a knee prosthesis with fixed plate with conservation of the posterior cruciate ligaments.
- un second type d'élément fémoral apte à coopérer avec un plateau fixe de l'embase tibiale, pour constituer une prothèse du genou postéro-stabilisée à plateau fixe. Un autre brevet français FR2692476 décrit une prothèse totale du genou du type à glissement, comprenant un élément fémoral dont les patins condyliens coopèrent en appui sur un plateau d'un élément tibial. Les éléments tibial et fémoral présentent en combinaison, des moyens complémentaires de butée et de guidage réglables et amovibles, aptes à assurer la stabilisation des deux éléments en respectant 1 ' iso étrie ligamentaire quand le ligament antérieur ou les deux ligaments croisés sont détruits. On connaît également le brevet français- A second type of femoral element capable of cooperating with a fixed plate of the tibial base, to constitute a posterior stabilized knee prosthesis with fixed plate. Another French patent FR2692476 describes a total knee prosthesis of the sliding type, comprising a femoral element whose condylar pads cooperate in abutment on a plate of a tibial element. The tibial and femoral elements have, in combination, complementary stop and guide means which are adjustable and removable, capable of ensuring the stabilization of the two elements while respecting the ligament iso when the anterior ligament or the two cruciate ligaments are destroyed. We also know the French patent
FR2665073. Ce document divulgue une prothèse totale du genou du type à glissement, comprenant une partie fémorale bi- condylienne dont la face externe profilée vient en contact, appui et centrage sur un élément intermédiaire en polyéthylène haute-densité, ledit élément intermédiaire étant positionné et fixé sur la face supérieure formant embase métallique de l'élément tibial, et en ce que la partie supérieure de la partie tibiale est agencée avec une pluralité d'ouvertures de positionnement par rapport à la partie intermédiaire, cette dernière comprenant deux plots de centrage pour s ' engager dans des ouvertures de positionnement autorisant ainsi un réglage en position du plateau intermédiaire par rapport à 1 'élément tibial.FR2665073. This document discloses a total knee prosthesis of the sliding type, comprising a bi-condylar femoral part, the profiled external face of which comes into contact, support and centering on an intermediate element of high-density polyethylene, said intermediate element being positioned and fixed on the upper face forming a metal base of the 'tibial element, and in that the upper part of the tibial part is arranged with a plurality of positioning openings relative to the intermediate part, the latter comprising two centering pads to engage in positioning openings thus allowing an adjustment in position of the intermediate plate relative to one tibial element.
Le brevet européen EP183670 décrit une articulation artificielle ménisque-tibia pour une prothèse d'articulation du genou comprenant au moins un composant tibial sur lequel le ménisque est disposé de manière à pouvoir se déplacer ou être mobile. Le ménisque présente une surface de glissement dans une large mesure plane contre le composant tibial, le ménisque ou le composant tibial comportant des organes de commande de direction donnant au ménisque une aptitude au mouvement dans toutes les directions le long du composant tibial, mais ces organes de commande de direction étant également disposés de façon à limiter l'amplitude du mouvement. Ces différentes prothèses de l'art antérieur présentent toutefois toutes des déplacements contraints, dont le confort n'est pas totalement satisfaisant pour la personne ainsi appareillée.European patent EP183670 describes an artificial meniscus-tibia joint for a knee joint prosthesis comprising at least one tibial component on which the meniscus is disposed so as to be able to move or be mobile. The meniscus has a largely planar sliding surface against the tibial component, the meniscus or the tibial component having directional control members giving the meniscus the ability to move in all directions along the tibial component, but these members direction control elements being also arranged so as to limit the amplitude of the movement. These different prostheses of the prior art, however, all have constrained displacements, the comfort of which is not entirely satisfactory for the person thus fitted.
L'objet de l'invention est de remédier à cet inconvénient en proposant une prothèse autorisant un degré de liberté supplémentaire, et permettant ainsi d'éviter le blocage de l'articulation lors de certains mouvements du genou.The object of the invention is to remedy this drawback by proposing a prosthesis allowing an additional degree of freedom, and thus making it possible to avoid blocking of the joint during certain movements of the knee.
A cet effet, l'invention concerne plus particulièrement une prothèse de genou composée de : - a) au moins un composant tibial présentant une première surface d'appui,To this end, the invention relates more particularly to a knee prosthesis composed of: a) at least one tibial component having a first bearing surface,
- b) au moins un composant méniscal possédant une deuxième surface d'appui, qui entre en contact par glissement avec la première surface d'appui du composant tibial pour subir un mouvement de glissement par rapport à ce dernier pendant le mouvement de l'articulation, le composant méniscal ayant une troisième surface d'appui, et- b) at least one meniscal component having a second bearing surface, which comes into sliding contact with the first bearing surface of the tibial component to undergo a sliding movement relative to the latter during the movement of the joint , the meniscal component having a third bearing surface, and
- c) un composant fémoral ayant une quatrième surface d'appui qui entre en contact par glissement avec la troisième surface d'appui du composant méniscal, caractérisée en ce que le composant tibial est pourvu d'au moins une cavité dans laquelle pénètre au moins une partie formant saillie par rapport à la deuxième surface d'appui d'un composant méniscal, la cavité et la partie saillante étant conformées de manière à autoriser des mouvements latéraux et des mouvements de rotation d'au moins un composant méniscal par rapport au composant tibial, les mouvements de rotation s'effectuant selon au moins un axe sensiblement perpendiculaire à la première surface d'appui et excentré latéralement par rapport au tibia.- c) a femoral component having a fourth bearing surface which comes into sliding contact with the third bearing surface of the meniscal component, characterized in that the tibial component is provided with at least one cavity into which penetrates at least a portion projecting from the second bearing surface of a meniscal component, the cavity and the protruding portion being shaped so as to allow lateral movements and rotational movements of at least one meniscal component relative to the component tibial, the rotational movements taking place along at least one axis substantially perpendicular to the first bearing surface and eccentric laterally with respect to the tibia.
La prothèse selon l'invention présente une possibilité de rotation par rapport à un axe virtuel déporté latéralement à l'extérieur de la plate-forme tibiale. Le centre de rotation peut être déplacé en un point dont la projection sur le plan perpendiculaire à l'axe du tibia est extérieur à la prothèse.The prosthesis according to the invention has a possibility of rotation relative to a virtual axis offset laterally outside the tibial platform. The center of rotation can be moved to a point whose projection on the plane perpendicular to the axis of the tibia is outside the prosthesis.
Dans les prothèses selon l'art antérieur, par exemple selon le brevet O-1-79/00739, le composant méniscal est mobile en rotation selon un axe correspondant à l'axe du tibia. Une telle prothèse n'est pas tout-à-fait adapté à un mouvement anatomique, et conduit donc à une démarche disgracieuse. La prothèse selon la présente invention permet de mieux reproduire le mouvement naturel de flexion ou d'extension du genou. On peut envisager plusieurs réalisations différentes.In prostheses according to the prior art, for example according to patent O-1-79 / 00739, the meniscal component is movable in rotation along an axis corresponding to the axis of the tibia. Such a prosthesis is not entirely adapted to an anatomical movement, and therefore leads to an unsightly gait. The prosthesis according to the present invention makes it possible to better reproduce the natural movement of flexion or extension of the knee. We can consider several different realizations.
Selon une première variante de réalisation, la prothèse selon l'invention comporte deux composants méniscaux présentant chacun une partie formant saillie par rapport à la seconde surface et en ce que le composant tibial (1) présente deux cavités susceptible de coopérer chacune avec la partie saillante de l'un des composants méniscaux. Avantageusement, les cavités sont fermées par un rebord continu.According to a first alternative embodiment, the prosthesis according to the invention comprises two meniscal components each having a part projecting from the second surface and in that the tibial component (1) has two cavities capable of cooperating each with the projecting part of one of the meniscal components. Advantageously, the cavities are closed by a continuous rim.
De préférence, les rebords ont une épaisseur constante sur une extension d'une demi-circonférence des cavités où ils bordent l'élément de tibia. Selon un mode de réalisation particulier, le rebord est situé pour limiter les rotations de pivotement du ménisque dans des courses angulaires au plus égales aux courses naturelles.Preferably, the edges have a constant thickness over an extension of a half-circumference of the cavities where they border the tibia element. According to a particular embodiment, the rim is located to limit the pivoting rotations of the meniscus in angular strokes at most equal to the natural strokes.
Selon une deuxième variante de réalisation de l'invention, la prothèse du genou selon l'invention comporte:According to a second alternative embodiment of the invention, the knee prosthesis according to the invention comprises:
- a) au moins un composant tibial présentant une première surface d'appui,a) at least one tibial component having a first bearing surface,
- b) un composant méniscal possédant une deuxième surface d'appui, qui entre en contact par glissement avec la première surface d'appui du composant tibial pour subir un mouvement de glissement par rapport à ce dernier pendant le mouvement de l'articulation, le composant méniscal ayant une troisième surface d'appui, et - c) un composant fémoral ayant une quatrième surface d'appui qui entre en contact par glissement avec la troisième surface d'appui du composant méniscal caractérisé en ce que le composant méniscal est constitué par une pièce unique, en ce que la première surface d'appui du composant tibial est en forme de haricot, et en ce que la seconde surface d'appui du composant méniscal est également en forme de haricot de plus petite dimension dans le sens anthéro- postérieur la forme desdites première et seconde surfaces d'appui étant complémentaire et déterminée de façon à permettre un déplacement limité en rotation et en déplacement linéaire du composant méniscal par rapport au composant tibial.b) a meniscal component having a second bearing surface, which comes into sliding contact with the first bearing surface of the tibial component to undergo a sliding movement relative to the latter during the movement of the joint, the meniscal component having a third bearing surface, and - c) a femoral component having a fourth bearing surface which comes into sliding contact with the third bearing surface of the meniscal component characterized in that the meniscal component consists of a single piece, in that the first bearing surface of the tibial component is in the form of a bean, and in that the second bearing surface of the meniscal component is also in the form of bean of smaller dimension in the antero-posterior direction the shape of said first and second bearing surfaces being complementary and determined so as to allow a movement limited in rotation and in linear movement of the meniscal component with respect to the tibial component.
Avantageusement, le composant tibial présente une surface d'appui formée de deux zones latérales, chacune étant délimitée extérieurement par un bord arrondi convexe, et intérieurement par un bord arrondi convexe s 'étendant depuis l'avant du plateau tibial jusqu'à un axe transversal sensiblement médian, les deux zones latérales étant réunies par une zone centrale délimitée à l'avant par un bord courbe concave prolongeant à chacune de ses extrémités l'un des bords intérieurs, et à l'arrière par un bord prolongeant à chacune de ses extrémités l'un des bords extérieurs.Advantageously, the tibial component has a bearing surface formed by two lateral zones, each being delimited externally by a rounded convex edge, and internally by a rounded convex edge extending from the front of the tibial plateau to a transverse axis. substantially median, the two lateral zones being joined by a central zone delimited at the front by a concave curved edge extending at each of its ends one of the interior edges, and at the rear by an edge extending at each of its ends one of the outer edges.
Selon un mode de réalisation préféré, le composant tibial présente une surface d'appui plane délimitée sur sa périphérie par un bord saillant, le composant méniscal présentant une surface d'appui propre à coopérer avec la surface d'appui du composant tibial de façon à autoriser des déplacements en translation et en rotation limité.According to a preferred embodiment, the tibial component has a planar bearing surface delimited on its periphery by a projecting edge, the meniscal component having a bearing surface capable of cooperating with the bearing surface of the tibial component so as to allow limited translational and rotational movements.
Selon une autre caractéristique avantageuse, le composant méniscal présente une surface d'appui formée de deux zones latérales, chacune étant délimitée extérieurement par un bord arrondi convexe, et intérieurement par un bord arrondi convexe s 'étendant depuis 1 'avant du plateau tibial jusqu'à un axe transversal sensiblement médian, les deux zones latérales étant réunies par une zone centrale délimitée à l'avant par un bord courbe concave prolongeant à chacune de ses extrémités l'un des bords intérieurs, et à l'arrière par un bord prolongeant à chacune de ses extrémités l'un des bords extérieurs. De préférence, la surface d'appui du composant méniscal constitue une surface saillante plane. L'invention sera mieux comprise à la lecture de la description qui suit, faisant référence aux dessins annexés où :According to another advantageous characteristic, the meniscal component has a bearing surface formed by two lateral zones, each being delimited externally by a rounded convex edge, and internally by a rounded convex edge extending from the front of the tibial plateau to to a substantially median transverse axis, the two lateral zones being joined by a central zone delimited at the front by a concave curved edge extending at each of its ends one of the interior edges, and at the rear by an edge extending to each of its ends one of the outer edges. Preferably, the bearing surface of the meniscal component constitutes a flat projecting surface. The invention will be better understood on reading the description which follows, referring to the accompanying drawings in which:
- la figure 1 vue de dessus du composant tibial et du composant méniscal en position postérieure ;- Figure 1 top view of the tibial component and the meniscal component in the posterior position;
- la figure 2 représente une vue du composant tibial et du composant méniscal selon un plan de coupe AA' ;- Figure 2 shows a view of the tibial component and the meniscal component along a section plane AA ';
- la figure 3 représente une vue du composant tibial et du composant méniscal selon un plan de coupe BB' ; - les figures 4 à 8 représentent des vues de dessus du composant tibial et du composant méniscal dans différentes positions relatives.- Figure 3 shows a view of the tibial component and the meniscal component along a section plane BB '; - Figures 4 to 8 show top views of the tibial component and the meniscal component in different relative positions.
- la figure 9 représente une vue d'une variante de réalisation à deux composants méniscaux indépendants ; - les figures 10 à 14 représentent les mouvements des composants méniscaux par rapport au composant tibial ;- Figure 9 shows a view of an alternative embodiment with two independent meniscal components; - Figures 10 to 14 show the movements of the meniscal components relative to the tibial component;
- la figure 15 représente une vue d'une autre variante de réalisation à deux composants méniscaux indépendants.- Figure 15 shows a view of another alternative embodiment with two independent meniscal components.
La figure 1 représente une vue de dessus du composant tibial (1) muni du composant méniscal (2) . Le composant tibial est symétrique par rapport à un plan médian BB ' . Le composant tibial (1) est fixé sur le tibia de manière connue et visible sur les figures 2 et 3, par une ou plusieurs pointes (3, 4) rainurées ou recouvertes d'un matériel biocompatible destinées à pénétrer dans le tissu spongieux. Les dimensions du composant tibial s'inscrivent dans un rectangle d'environ 80 x 55 millimètres. Les dimensions du composant méniscal s'inscrivent dans un rectangle d'environ 60 x 30 millimètres.FIG. 1 represents a top view of the tibial component (1) provided with the meniscal component (2). The tibial component is symmetrical with respect to a median plane BB '. The tibial component (1) is fixed to the tibia in a known manner and visible in FIGS. 2 and 3, by one or more points (3, 4) grooved or covered with a biocompatible material intended to penetrate into the spongy tissue. The dimensions of the tibial component are within a rectangle of approximately 80 x 55 millimeters. The dimensions of the meniscal component are within a rectangle of approximately 60 x 30 millimeters.
La surface supérieure (5) du composant tibial présente une zone (6) en forme de haricot, symétrique par rapport à l'axe antéro-postérieur médian BB'. Le composant tibial (1) ainsi que le composant méniscal (2) présentent des echancrures (7) forme en U afin de dégager une ouverture (5) pour le passage des ligaments croisés. La surface supérieure (8, 9) est complémentaire avec la surface de contact du composant fémoral fixé sur 1 'os fémoral de façon connue. La zone (6) en forme de haricot présente deux zones latérales (11, 12) réunies par une zone centrale (13) . Elle est délimitée par un rebord saillant (14) présentant un profil en queue d'aronde, avec une bordure inférieure (15) surmontée par une bordure supérieure (16) s ' étendant vers l'intérieur de la zone de contact entre le talon (17) du composant méniscal et la surface de contact plane (28) du composant tibial. Le talon (17) présente un bord périphérique complémentaire.The upper surface (5) of the tibial component has a bean-shaped zone (6) symmetrical with respect to the median anteroposterior axis BB '. The tibial component (1) as well as the meniscal component (2) have notches (7) U-shaped so to clear an opening (5) for the passage of the cruciate ligaments. The upper surface (8, 9) is complementary with the contact surface of the femoral component fixed on the femoral bone in a known manner. The bean-shaped zone (6) has two lateral zones (11, 12) joined by a central zone (13). It is delimited by a projecting rim (14) having a dovetail profile, with a lower edge (15) surmounted by an upper edge (16) extending inwardly of the contact zone between the heel ( 17) of the meniscal component and the planar contact surface (28) of the tibial component. The heel (17) has a complementary peripheral edge.
Les deux zones latérales (11, 12) sont symétriques par rapport à l'axe antéro-postérieur BB' .The two lateral zones (11, 12) are symmetrical with respect to the anteroposterior axis BB '.
La zone latérale (11) sera décrite ci-après plus en détail, étant entendu que la deuxième zone latérale (12) présente les mêmes caractéristiques.The lateral zone (11) will be described below in more detail, it being understood that the second lateral zone (12) has the same characteristics.
La zone latérale (11) présente une forme générale ovale, avec un bord antérieur (18) de forme semi- circulaire prolongé extérieurement par un bord extérieur (19) arrondi s ' étendant globalement parallèlement à l'axe antéro-postérieur BB' , et prolongé sur le bord postérieur par un bord (20) formant sensiblement un quart de cercle. Sur le bord intérieur, le bord antérieur (18) de forme semi-circulaire est prolongé par un bord intérieur (19) arrondi s 'étendant globalement parallèlement à l'axe antéro-postérieur BB' et longeant 1 'échancrure (7) .The lateral zone (11) has a generally oval shape, with a semicircular front edge (18) extended externally by a rounded external edge (19) extending generally parallel to the anteroposterior axis BB ', and extended on the rear edge by an edge (20) substantially forming a quarter of a circle. On the inner edge, the front edge (18) of semi-circular shape is extended by a rounded inner edge (19) extending generally parallel to the anteroposterior axis BB 'and along the notch (7).
Les deux zones latérales (11, 12) sont réunies sur le coté antérieur par un bord (21) en forme de demi- cercle concave, vue de la zone d'appui (6), et sur le coté postérieur par un bord (22) s ' étendant suivant un axe général perpendiculaire à 1 'axe BB' , de manière convexe vu du coté intérieur de la zone d'appui (6) . Le composant méniscal (2) présente un talon (18) dont la forme générale est équivalente à celle de la zone d'appui (6) du composant tibial (1) , mais dont les dimensions et les courbures sont différentes pour autoriser une mobilité limitée en rotation et en translation, comme représenté en figures 4 à 8. La figure 4 représente un exemple de déplacement en rotation par rapport au centre de la prothèse.The two lateral zones (11, 12) are joined on the front side by an edge (21) in the form of a concave semicircle, seen from the support zone (6), and on the rear side by an edge (22 ) extending along a general axis perpendicular to the 'BB' axis, convexly seen from the inside of the support zone (6). The meniscal component (2) has a heel (18) whose general shape is equivalent to that of the area support (6) of the tibial component (1), but whose dimensions and curvatures are different to allow limited mobility in rotation and in translation, as shown in Figures 4 to 8. Figure 4 shows an example of displacement in rotation relative to the center of the prosthesis.
L'une des branches latérales arrondies (25) du talon méniscal (17) vient s'avancer jusqu'au bord antérieur (18) de la zone latérale (11) correspondant. La partie centrale concave (26) bascule latéralement, du coté de cette zone latérale (11) . La branche latérale opposée (27) vient reculer contre le bord postérieur (29) de la zone latérale (12) .One of the rounded lateral branches (25) of the meniscal heel (17) comes to the front edge (18) of the corresponding lateral zone (11). The concave central part (26) rocks laterally, on the side of this lateral zone (11). The opposite lateral branch (27) recedes against the rear edge (29) of the lateral zone (12).
La figure 5 représente un autre mode de déplacement, suivant lequel le bord concave postérieur (30) du talon méniscal (17) vient en appui contre le bord antérieur concave (21) du composant tibial.FIG. 5 represents another mode of displacement, according to which the posterior concave edge (30) of the meniscal heel (17) bears against the concave anterior edge (21) of the tibial component.
Les deux composants peuvent ainsi ce déplacer suivant une rotation correspondant au développement des courbures des deux bords antérieurs (21, 30) .The two components can thus move in a rotation corresponding to the development of the curvatures of the two front edges (21, 30).
Les figures 6 et 7 représentent des modes de déplacement en translation parallèlement à l'axe postéro- antérieur BB' .Figures 6 and 7 show modes of displacement in translation parallel to the postero-anterior axis BB '.
La figure 8 représente un déplacement combiné de translation et de rotation.FIG. 8 represents a combined displacement of translation and rotation.
La figure 9 représente une vue d'une variante de réalisation à deux composants méniscaux indépendants.FIG. 9 shows a view of an alternative embodiment with two independent meniscal components.
Le composant tibial (1) est une plate-forme plane présentant une première surface de contact (5) munie de deux cavités oblongues (30, 31) à fond sensiblement plan, de profondeur faible et constante. Ces cavités (30, 31) permettant le déplacement en translation et en rotation de deux tenons saillants complémentaires (33, 34) solidaire chacune de l'un des composants méniscaux (35, 36) . Les tenons saillants (33, 34) présentent une épaisseur faible et constante pour un engagement dans les cavités oblongues (30, 31) et pour autoriser un mouvement glissant en rotation et en translation, à l'intérieur de limites définies par des rebords (37, 38) .The tibial component (1) is a flat platform having a first contact surface (5) provided with two oblong cavities (30, 31) with a substantially flat bottom, of shallow and constant depth. These cavities (30, 31) allowing the displacement in translation and in rotation of two complementary projecting studs (33, 34) each secured to one of the meniscal components (35, 36). The protruding studs (33, 34) have a low and constant thickness for engagement in the oblong cavities (30, 31) and to allow a sliding movement in rotation and in translation, within limits defined by flanges (37, 38).
Comme on le voit bien sur les figures 10 à 14 représentant les mouvements des composants méniscaux par rapport au composant tibial, les cavités (30, 31) ont des surfaces inégales et sont placées de sorte que les tenons (33, 34) butent tous deux contre les extrémités arrière des cavités (30, 31) dans la position d'extension de la jambe figurant de la figure 10 et contre les extrémités avant de ces deux cavités dans la position de flexion maximale illustrée par la figure 11.As can be seen in Figures 10 to 14 showing the movements of the meniscal components relative to the tibial component, the cavities (30, 31) have uneven surfaces and are placed so that the pins (33, 34) both abut against the rear ends of the cavities (30, 31) in the leg extension position shown in FIG. 10 and against the front ends of these two cavities in the maximum bending position illustrated in FIG. 11.
Les droites issues des centres des tenons (33, 34) dans ces deux positions se coupent en un point 0 qui constitue un centre de pivotement de l'articulation et qui est immobile ou presque au cours du déplacement des tenons (33, 34) . Les cavités (30, 31) sont cependant plus larges que les tenons (33, 34) pour que des mouvements légèrement différents soient autorisés et qu'une plus grande souplesse de l'articulation soit obtenue.The straight lines coming from the centers of the studs (33, 34) in these two positions intersect at a point 0 which constitutes a pivot center of the joint and which is almost immobile during the movement of the studs (33, 34). The cavities (30, 31) are however wider than the tenons (33, 34) so that slightly different movements are authorized and that greater flexibility of the joint is obtained.
Les cavités (30, 31) sont entourées par des rebords continus présentant une partie principale (37, 38) de largeur constante et s ' étendant sur un peu plus de la moitié de la circonférence des cavités (30, 31) . L'épaisseur des rebords, ou plus précisément de ces parties principalesThe cavities (30, 31) are surrounded by continuous flanges having a main part (37, 38) of constant width and extending over a little more than half the circumference of the cavities (30, 31). The thickness of the edges, or more precisely of these main parts
(37, 38) est choisie pour que la pression des composants méniscaux (37, 38) ne devienne jamais excessive. Elle est de trois millimètres dans une réalisation où les pièces sont en polyéthylène de haute densité pour les parties portantes, subissant le frottement et la pression de contact, et en acier inoxydable, en alliage à base de cobalt ou en alliage de titane pour le reste.(37, 38) is chosen so that the pressure of the meniscal components (37, 38) never becomes excessive. It is three millimeters in an embodiment where the parts are made of high density polyethylene for the load-bearing parts, undergoing friction and contact pressure, and of stainless steel, of cobalt-based alloy or of titanium alloy for the rest .
La figure 12 représente une réalisation légèrement différente d'une prothèse selon cette variante. Le composant tibial (1) présente deux cavités (40, 41) semblables et symétriques avec une largeur de l'ordre de 26 millimètres et une longueur de 39 millimètres pour des tenons (42) circulaires d'un diamètre de 23 millimètres, et non pas oblongues comme dans l'exemple de réalisation précédent. Selon que la prothèse sera placée sur un genou droit ou un genou gauche, on obtiendra, à partir d'un état d'extension illustré par la figure 12, et semblable à celui de la figure 10, un état de flexion représenté soit à la figure 13, soit à la figure 14. Un des tenons (42) parvient à l'extrémité de la cavité dans lequel il pénètre, alors que l'autre tenon s'arrête à peu près au centre de l'autre cavité. Il est nécessaire dans cette réalisation que les cavités (40, 41) soient sensiblement plus larges que les tenons (42) pour que les rotations soient possibles dans les deux sens. La figure 15 représente une conception un peu modifiée dont la finalité est analogue à celle de la figure 12, c'est-à-dire que le composant tibial (53) est conçu pour être utilisé indifféremment pour des genoux droits et gauches. Le composant tibial (53) présente deux rainures (56) semblables rectilignes et parallèles. Le composant méniscal (54) formé de deux éléments (58, 59) associés chacun à une rainure (56) par des tenons circulaires (57) . Un jeu latéral suffisant est prévu pour autoriser des rotations de 1 'articulation dans les deux sens. II va de soi que de nombreuses modifications peuvent être apportées à la prothèse décrite et représentée à titre d'exemple non limitatif sans sortir du cadre de 1 ' invention. Figure 12 shows a slightly different embodiment of a prosthesis according to this variant. The tibial component (1) has two similar and symmetrical cavities (40, 41) with a width of the order of 26 millimeters and a length of 39 millimeters for circular tenons (42) with a diameter of 23 millimeters, and not oblong as in the previous embodiment example. Depending on whether the prosthesis will be placed on a right knee or a left knee, we will obtain, from a state of extension illustrated in FIG. 12, and similar to that of FIG. 10, a state of bending represented either at Figure 13, or Figure 14. One of the tenons (42) reaches the end of the cavity into which it enters, while the other tenon stops approximately in the center of the other cavity. It is necessary in this embodiment that the cavities (40, 41) are substantially wider than the studs (42) so that the rotations are possible in both directions. FIG. 15 represents a slightly modified design, the purpose of which is similar to that of FIG. 12, that is to say that the tibial component (53) is designed to be used indifferently for right and left knees. The tibial component (53) has two similar straight and parallel grooves (56). The meniscal component (54) formed of two elements (58, 59) each associated with a groove (56) by circular studs (57). Sufficient lateral play is provided to allow rotations of the joint in both directions. It goes without saying that numerous modifications can be made to the prosthesis described and shown by way of nonlimiting example without departing from the scope of the invention.

Claims

REVENDICATIONS
1 - Prothèse de genou composée de1 - Knee prosthesis composed of
- a) au moins un composant tibial (1) présentant une première surface d'appui,a) at least one tibial component (1) having a first bearing surface,
- b) au moins un composant méniscal (2) possédant une deuxième surface d'appui, qui entre en contact par glissement avec la première surface d'appui du composant tibial (1) pour subir un mouvement de glissement par rapport à ce dernier pendant le mouvement de l'articulation, le composant méniscal (2) ayant une troisième surface d'appui, et- b) at least one meniscal component (2) having a second bearing surface, which comes into sliding contact with the first bearing surface of the tibial component (1) to undergo a sliding movement relative to the latter during the movement of the joint, the meniscal component (2) having a third bearing surface, and
- c) un composant fémoral ayant une quatrième surface d'appui qui entre en contact par glissement avec la troisième surface d'appui du composant méniscal (2), caractérisée en ce que le composant tibial (1) est pourvu d'au moins une cavité dans laquelle pénètre au moins une partie formant saillie par rapport à la deuxième surface d'appui d'un composant méniscal (2), la cavité et la partie saillante étant conformées de manière à autoriser des mouvements latéraux et des mouvements de rotation d'au moins un composant méniscal par rapport au composant tibial, les mouvements de rotation s'effectuant selon un axe sensiblement perpendiculaire à la première surface d'appui et excentré latéralement par rapport au tibia.- c) a femoral component having a fourth bearing surface which comes into sliding contact with the third bearing surface of the meniscal component (2), characterized in that the tibial component (1) is provided with at least one cavity into which at least one protruding part penetrates relative to the second bearing surface of a meniscal component (2), the cavity and the protruding part being shaped so as to allow lateral movements and rotational movements of at least one meniscal component with respect to the tibial component, the rotational movements taking place along an axis substantially perpendicular to the first bearing surface and eccentrically laterally with respect to the tibia.
2 - Prothèse de genou selon la revendication 1, caractérisée en ce qu'elle comporte deux composants méniscaux présentant chacun une partie formant saillie par rapport à la seconde surface et en ce que le composant tibial (1) présente deux cavités susceptible de coopérer chacune avec la partie saillante de l'un des composants méniscaux. 3 - Prothèse de genou selon 1 'une quelconque des revendications précédentes, caractérisée en ce que les cavités sont fermées par un rebord continu.2 - Knee prosthesis according to claim 1, characterized in that it comprises two meniscal components each having a portion projecting from the second surface and in that the tibial component (1) has two cavities capable of cooperating each with the protruding part of one of the meniscal components. 3 - Knee prosthesis according to any one of the preceding claims, characterized in that the cavities are closed by a continuous rim.
4 - Prothèse de genou selon la revendication 3 , caractérisée en ce que les rebords ont une épaisseur constante sur une extension d'une demi-circonférence des cavités où ils bordent l'élément de tibia.4 - Knee prosthesis according to claim 3, characterized in that the edges have a constant thickness over an extension of a half-circumference of the cavities where they border the tibia element.
5 - Prothèse de genou selon la revendication 3, caractérisée en ce que le rebord est situé pour limiter les rotations de pivotement du ménisque dans des courses angulaires au plus égales aux courses naturelles .5 - Knee prosthesis according to claim 3, characterized in that the flange is located to limit the pivoting rotations of the meniscus in angular strokes at most equal to natural strokes.
6 - Prothèse de genou selon la revendication 1 caractérisée en ce que le composant méniscal (2) est constitué par une pièce unique, en ce que la première surface d'appui du composant tibial (1) est en forme de haricot, et en ce que la seconde surface d'appui (6) du composant méniscal (2) est également en forme de haricot de plus petite dimension dans le sens anthéro-postérieur la forme desdites première et seconde surfaces d'appui étant complémentaires et déterminées de façon à permettre un déplacement limité en rotation et en déplacement linéaire du composant méniscal (2) par rapport au composant tibial (1) .6 - Knee prosthesis according to claim 1 characterized in that the meniscal component (2) is constituted by a single piece, in that the first bearing surface of the tibial component (1) is in the form of a bean, and in that that the second bearing surface (6) of the meniscal component (2) is also in the shape of a bean of smaller dimension in the antero-posterior direction, the shape of said first and second bearing surfaces being complementary and determined so as to allow a displacement limited in rotation and in linear displacement of the meniscal component (2) relative to the tibial component (1).
7 - Prothèse de genou selon la revendication 6, caractérisée en ce que le composant tibial (1) présente une surface d'appui formée de deux zones latérales, chacune étant délimitée extérieurement par un bord arrondi convexe, et intérieurement par un bord arrondi convexe s ' étendant depuis l'avant du composant tibial (1) jusqu'à un axe transversal sensiblement médian, les deux zones latérales étant réunies par une zone centrale délimitée à l'avant par un bord courbe concave prolongeant à chacune de ses extrémités l'un des bords intérieurs, et à l'arrière par un bord prolongeant à chacune de ses extrémités l'un des bords extérieurs.7 - Knee prosthesis according to claim 6, characterized in that the tibial component (1) has a bearing surface formed by two lateral zones, each being delimited externally by a rounded convex edge, and internally by a rounded convex edge s 'extending from the front of the tibial component (1) to a substantially median transverse axis, the two lateral zones being joined by a central zone delimited at the front by a concave curved edge extending at each of its ends one inner edges, and at the back by a edge extending at each of its ends one of the outer edges.
8 - Prothèse de genou selon la revendication 7, caractérisée en ce que le composant tibial (1) présente une surface d'appui plane délimitée sur sa périphérie par un bord saillant, le composant méniscal (2) présentant une surface d'appui propre à coopérer avec la surface d'appui du composant tibial (1) de façon à autoriser des déplacements en translation et en rotation limitée.8 - Knee prosthesis according to claim 7, characterized in that the tibial component (1) has a flat bearing surface delimited on its periphery by a projecting edge, the meniscal component (2) having a bearing surface specific to cooperate with the bearing surface of the tibial component (1) so as to allow movements in translation and limited rotation.
9 - Prothèse de genou selon 1 'une quelconque des revendications 6 à 8, caractérisée en ce que le composant méniscal (2) présente une surface d'appui formée de deux zones latérales, chacune étant délimitée extérieurement par un bord arrondi convexe, et intérieurement par un bord arrondi convexe s 'étendant depuis l'avant du composant tibial (1) jusqu'à un axe transversal sensiblement médian, les deux zones latérales étant réunies par une zone centrale délimitée à l'avant par un bord courbe concave prolongeant à chacune de ses extrémités l'un des bords intérieurs, et à l'arrière par un bord prolongeant à chacune de ses extrémités l'un des bords extérieurs. 9 - Knee prosthesis according to any one of claims 6 to 8, characterized in that the meniscal component (2) has a bearing surface formed by two lateral zones, each being delimited externally by a rounded convex edge, and internally by a convex rounded edge extending from the front of the tibial component (1) to a substantially median transverse axis, the two lateral zones being joined by a central zone delimited at the front by a concave curved edge each extending from its ends one of the interior edges, and at the rear by an edge extending at each of its ends one of the exterior edges.
EP95918045A 1994-05-04 1995-04-21 Knee prosthesis with a movable meniscus Withdrawn EP0758218A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9405471 1994-05-04
FR9405471A FR2719466B1 (en) 1994-05-04 1994-05-04 Knee prosthesis with movable meniscus.
PCT/FR1995/000530 WO1995030390A1 (en) 1994-05-04 1995-04-21 Knee prosthesis with a movable meniscus

Publications (1)

Publication Number Publication Date
EP0758218A1 true EP0758218A1 (en) 1997-02-19

Family

ID=9462865

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95918045A Withdrawn EP0758218A1 (en) 1994-05-04 1995-04-21 Knee prosthesis with a movable meniscus

Country Status (3)

Country Link
EP (1) EP0758218A1 (en)
FR (1) FR2719466B1 (en)
WO (1) WO1995030390A1 (en)

Families Citing this family (43)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2312168B (en) * 1996-04-17 1999-11-03 Finsbury Meniscal knee prosthesis
GB2312167A (en) * 1996-04-17 1997-10-22 Finsbury An endoprosthetic knee
FR2756483B1 (en) * 1996-12-02 1999-08-06 Gerard Ysebaert IMPROVED KNEE PROSTHETIC JOINT
US8882847B2 (en) 2001-05-25 2014-11-11 Conformis, Inc. Patient selectable knee joint arthroplasty devices
US7534263B2 (en) 2001-05-25 2009-05-19 Conformis, Inc. Surgical tools facilitating increased accuracy, speed and simplicity in performing joint arthroplasty
US7468075B2 (en) 2001-05-25 2008-12-23 Conformis, Inc. Methods and compositions for articular repair
US20040133276A1 (en) 2002-10-07 2004-07-08 Imaging Therapeutics, Inc. Minimally invasive joint implant with 3-Dimensional geometry matching the articular surfaces
US9603711B2 (en) 2001-05-25 2017-03-28 Conformis, Inc. Patient-adapted and improved articular implants, designs and related guide tools
US8545569B2 (en) 2001-05-25 2013-10-01 Conformis, Inc. Patient selectable knee arthroplasty devices
US8083745B2 (en) 2001-05-25 2011-12-27 Conformis, Inc. Surgical tools for arthroplasty
US8556983B2 (en) 2001-05-25 2013-10-15 Conformis, Inc. Patient-adapted and improved orthopedic implants, designs and related tools
US8234097B2 (en) 2001-05-25 2012-07-31 Conformis, Inc. Automated systems for manufacturing patient-specific orthopedic implants and instrumentation
US8480754B2 (en) 2001-05-25 2013-07-09 Conformis, Inc. Patient-adapted and improved articular implants, designs and related guide tools
US6053945A (en) * 1997-09-25 2000-04-25 Johnson & Johnson Professional, Inc. Joint prosthesis having controlled rotation
US5951603A (en) * 1997-09-25 1999-09-14 Johnson & Johnson Professional, Inc. Rotatable joint prosthesis with axial securement
US6010534A (en) * 1997-09-25 2000-01-04 Johnson & Johnson Professional, Inc. Rotatable tibial prosthesis with keyed axial securement
FR2769495B1 (en) * 1997-10-14 1999-12-31 Michel Timoteo KNEE PROSTHESIS
FR2773059B1 (en) * 1997-12-31 2000-06-02 Philippe Legay KNEE PROSTHESIS
US7239908B1 (en) 1998-09-14 2007-07-03 The Board Of Trustees Of The Leland Stanford Junior University Assessing the condition of a joint and devising treatment
ATE439806T1 (en) 1998-09-14 2009-09-15 Univ Leland Stanford Junior DETERMINING THE CONDITION OF A JOINT AND PREVENTING DAMAGE
US6319283B1 (en) 1999-07-02 2001-11-20 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6210445B1 (en) 1999-10-26 2001-04-03 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6217618B1 (en) 1999-10-26 2001-04-17 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6210444B1 (en) 1999-10-26 2001-04-03 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
AU9088701A (en) 2000-09-14 2002-03-26 Univ Leland Stanford Junior Assessing condition of a joint and cartilage loss
US8439926B2 (en) 2001-05-25 2013-05-14 Conformis, Inc. Patient selectable joint arthroplasty devices and surgical tools
US9308091B2 (en) 2001-05-25 2016-04-12 Conformis, Inc. Devices and methods for treatment of facet and other joints
US8951260B2 (en) 2001-05-25 2015-02-10 Conformis, Inc. Surgical cutting guide
DE60239674D1 (en) 2001-05-25 2011-05-19 Conformis Inc METHOD AND COMPOSITIONS FOR REPAIRING THE SURFACE OF JOINTS
CN1780594A (en) 2002-11-07 2006-05-31 康复米斯公司 Methods for determining meniscal size and shape and for devising treatment
AU2003902467A0 (en) * 2003-05-19 2003-06-05 Boris Rjazancev A prosthetic component, a method of attaching a prosthetic component to a bone, a method of performing knee replacement surgery and a frame for application to a knee joint during knee replacement surgery
US8623026B2 (en) 2006-02-06 2014-01-07 Conformis, Inc. Patient selectable joint arthroplasty devices and surgical tools incorporating anatomical relief
CN105030297A (en) 2006-02-06 2015-11-11 康复米斯公司 Patient selectable joint arthroplasty devices and surgical tools
WO2008101090A2 (en) 2007-02-14 2008-08-21 Conformis, Inc. Implant device and method for manufacture
US8682052B2 (en) 2008-03-05 2014-03-25 Conformis, Inc. Implants for altering wear patterns of articular surfaces
US9017334B2 (en) 2009-02-24 2015-04-28 Microport Orthopedics Holdings Inc. Patient specific surgical guide locator and mount
US8808303B2 (en) 2009-02-24 2014-08-19 Microport Orthopedics Holdings Inc. Orthopedic surgical guide
US8808297B2 (en) 2009-02-24 2014-08-19 Microport Orthopedics Holdings Inc. Orthopedic surgical guide
SG175229A1 (en) 2009-04-16 2011-11-28 Conformis Inc Patient-specific joint arthroplasty devices for ligament repair
AU2010327987B2 (en) 2009-12-11 2015-04-02 Conformis, Inc. Patient-specific and patient-engineered orthopedic implants
WO2012112694A2 (en) 2011-02-15 2012-08-23 Conformis, Inc. Medeling, analyzing and using anatomical data for patient-adapted implants. designs, tools and surgical procedures
US9486226B2 (en) 2012-04-18 2016-11-08 Conformis, Inc. Tibial guides, tools, and techniques for resecting the tibial plateau
US9675471B2 (en) 2012-06-11 2017-06-13 Conformis, Inc. Devices, techniques and methods for assessing joint spacing, balancing soft tissues and obtaining desired kinematics for joint implant components

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE450460B (en) * 1984-11-28 1987-06-29 Albrektsson Bjoern DEVICE IN ARTIFICIAL MENISH FOR A KNEE JOINT PROTECTION
FR2663536B1 (en) * 1990-06-22 1998-02-13 Implants Instr Ch Fab TOTAL SLIDING TYPE KNEE PROSTHESIS.
US5282868A (en) * 1991-06-17 1994-02-01 Andre Bahler Prosthetic arrangement for a complex joint, especially knee joint
GB9125311D0 (en) * 1991-11-28 1992-01-29 Biomet Ltd Prosthetic components
FR2698536B1 (en) * 1992-12-01 1996-07-05 Ysebaert Knee prosthesis.
FR2702369B1 (en) * 1993-03-10 1995-05-05 Gilles Voydeville Knee prosthesis.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9530390A1 *

Also Published As

Publication number Publication date
FR2719466B1 (en) 1997-06-06
FR2719466A1 (en) 1995-11-10
WO1995030390A1 (en) 1995-11-16

Similar Documents

Publication Publication Date Title
EP0758218A1 (en) Knee prosthesis with a movable meniscus
CA2726034C (en) Total knee prosthesis
EP0864305B1 (en) Ankle prosthesis
EP1354571B1 (en) Total knee prothesis
CH618873A5 (en)
EP0950387A1 (en) Knee prosthesis
CH687584A5 (en) Knee prosthesis
EP0346183A1 (en) Sliding knee prothesis
FR2663536A1 (en) Total knee prosthesis of the sliding type
EP0567705B1 (en) Posteriorly stabilized total knee prosthesis
FR2653992A1 (en) Total sliding knee prosthesis
BE1011626A3 (en) A total knee prosthesis tibial plateau mobile rotating.
FR2852819A1 (en) Knee prosthesis, has condyles and glenoid cavities with interior parts having radius of curvature more than radius of curvature of their posterior parts to ensure posterior stabilization
FR2721820A1 (en) KNEE PROSTHETIC JOINT, IN PARTICULAR ONE-COMPARTMENTAL KNEE PROSTHESIS, OR JOINT PROSTHESIS
FR2773059A1 (en) KNEE PROSTHESIS
BE1012454A3 (en) Device support or suppleance knee.
FR2758456A1 (en) Posterio-stabilised knee joint prosthesis
FR2913591A1 (en) Posterior stabilized type complete knee prosthesis, has femoral condyles of femoral implant and glenoid surfaces corresponding to intermediate plateau are such that medial lobe engages in round cavity during flexion movement of joint
FR2585236A1 (en) Unconstrained sliding knee endoprosthesis and method for manufacture thereof
FR2628316A1 (en) Whole knee prosthesis - has one piece implanted at end of femur, other at end of tibia articulating around cross member of T=piece
EP0707839A1 (en) Articular femoral prosthesis of a knee
FR2901690A1 (en) Total knee prosthesis for e.g. left knee of patient, has articulation stud decentred from inner side of tibial plate for taking into account movement of rotation and displacement of tibia during flexion to respect anatomy
FR2794640A1 (en) Knee joint prosthesis comprises a femoral component fixed in the lower extremity of the femur and comprising two condyles, an intermediate component keyed to the condyles via its upper hollowed surface, a tibial component
FR2742651A1 (en) Prosthesis for knee joint
EP2490626B1 (en) Total knee prosthesis having a mobile plate

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19961025

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 20000530

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20011023