DE2300810A1 - AS A SUBSTITUTE FOR THE HUMAN KNEE PROSTHESIS DEVICE - Google Patents

Description

5th January 1973

Jules Jean Marie Ernest HEEBERT Harcel Henri GROS, Aix Les Bains (France)

Prosthetic device used as a replacement for the human knee

The invention "relates to a replacement for the human Prosthetic knee serving device. The subject of the present invention is therefore a new total knee prosthesis, or in other words, a prosthetic device as a full replacement for the joint of the human knee that passes through Illness or, for example, damaged by injuries caused in an accident. This device is on the Knowledge built up that the movements of articulated objects are then furthest and best, i.e. suitable are to take place in all directions and circular orbits when using a full sphere that is in a hollow ball rotates.

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ORIGINAL INSPECTED

In the case of humans, the above universal movement is aimed at more or less complete type realized in two joints "at the hip joint and the shoulder joint, where the joint surfaces that are in contact with one another can be compared with spherical segments. In prosthesis technology, when it came down to Realizing artificial swivel joints e.g. from plastic material or from metal is this problem with Hip joint was realized in a very simple way. In fact, it was sufficient to articulate two spherical segments to one another, to be assigned, namely a hollow spherical segment that is attached to the hip bone and replaces the joint socket, and a full spherical segment, which replaces the head belonging to the thigh and a Rod is attached "

The problem that practitioners have to solve is how to attach the inert material to living bone. This problem seems to be solved nowadays through the use of an organic cement or binder (Methyl methacrylate) o

The execution of prostheses for the other joints, in particular for that of the knee, however, is much more difficult. When you see a knee working, it seems At first glance, only bending and stretching movements around

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run around an axis. The prosthetic solution So it seemed simple: it was enough to make a hinge, i.e. to ensure a rotary movement. So almost all knee prostheses designed up to now have been practically thawed on this principle.

However, what is actually going on in the knee? If one observes the flexion-extension movement of the knee, one can see that, starting from the extended position, there is no doubt a small turning movement at the beginning but does not exceed 10 ° by one point, whereupon the tibia gradually opens adjusted backwards by rotating around a point, which in turn turns to rear shifts in such a way that each point is assigned to a curve radius when viewed individually is the opposite of the previous

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is divorced. If you aen the locus of the center points records the rotary movements, you can see that it describes a line that is not just following shifts backwards and downwards, but also whose eadias decrease in size as you go back, thereby creating a to describe spiral curve.

The .bone-like articular surfaces belonging to the thigh Rod ends describe spirals (logarithmic) backwards, which guide the movement. As for the shin plates As for this, they are slightly convex from front to back (they should be concave to accommodate the curvature of the joint head front-to-back), which is why they slide and touch each other tangentially. But in In the transverse direction they are concave in order to adjust to the convexity in the transverse direction of the joint heads belonging to the leg.

So you can see how far you are from the simple rotary movement, i.e. from the circular movement around a point, but there is also a twisting or torsional movement at the same time as this movement, which is guided by the length by which the inner joint head is larger than the outer joint head. Just this movement it causes the leg to lose the abduction, the valgum, when it is flexed, which it had when it was extended.

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Furthermore, if the knee is stiff and rigid in the fully extended position, so is it to the extent that it is flexed becomes possible to make small lateral movements and torsional or twisting movements that result thanks to the design of the joint surfaces in the transverse direction. (Me with the joint head connected to the thigh e are strongly convex in the transverse direction, especially outer, the tibia plates are concave in the transverse direction, where they rise with their middle part over the circumference of the thorns, the task of which is important as a stop is). This is a kind of "bolls or swings or dangling".

To summarize the movement · involved in the process "Bending - stretching the knee" results in a movement from the front to the back the "pounding or swaying" results and a movement of the "rolling or dangling" results in the transverse direction. Pounding or swaying and dangling or rolling are words that define the system of movements of the Materialize the knee joint.

But what matters most is the way in which this movement is used while walking; the The important fact is that the step of stepping, or supporting, is practically without flexion accomplishes. As soon as a person walks and the stepping or supporting phase begins, the limb engages

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Completely
at the front of the ground, if it is stretched, or if it is not stretched, it is stretched as soon as the support by the sole is fully completed, then the opposite limb bends the knee and moves forward while the supported limb the extended The knee maintains its extended position and oscillates below the hip. During this entire phase, the knee is stiffly extended and the limb oscillates. When the limb to the. back limb, the support ceases, the knee bends to lift the foot, which is then pushed forward, and the cycle starts again turns and that when it turns it no longer supports itself. The resilience or strength of the knee is therefore only necessary in the extended position. For comfort when walking, it is even useful if the knee has a certain flexibility while bending. Due to its rigidity in all positions, the hinge obviously does not correspond to these ideas and conditions.

The new prosthesis described here corresponds exactly to these demands and conditions by trying to be voluntary To realize movements of the two types outlined above »

The üiatur achieved this success through a complex system ■ or «interplay, thanks to the potential for perfection that "prevails in all their constructions or realizations *

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-Yes-

But the prosthetic technology can artificially produce a similar, realize the obvious thing.

To explain this, we will first examine what is going on in the area of the hip, referring to the mechanical System thinks that is formed by the full sphere moving in a hollow sphere and carrying a rod (the ball head of the femur carried by the line of the mid-bone).

This movable ball belonging to the thigh can move in all directions in all azimuths in that of the hip bone Adjust associated fixed ball segment · Such a system can move 360 ° after all

Orientations

Directions and in all allow free.

Obviously, the most logical way to measure the displacements is to measure them in width and Express length. To speak as in spatial mechanics, assuming that the head of the femur is formed by the center of the system and that the thigh or the lower limb one Eadius starting from this center point, all adjustments can be made depending on the latitudes and longitudes measure very well. For example, all movements during flexion are measured in width and all sideways movements in Be expressed in terms of length. It is sufficient to define two axes of origin.

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The new knee prosthesis according to the invention uses the ball movement, but within certain limits: the movements in width are very extensive, exceeding 90 °, but the movements in length are very limited, for example lo °. This lo ° will correspond to the required movements of the "rail core ¹¹ '; the movement in width reproduces the" pitch ¹¹ .

In practice, this new prosthesis is realized in the following way: in its essential part it is carried out two small spherical caps formed, a full, movable cap that rolls in a fixed hollow cap. The full spherical cap is extended by a cylinder and the hollow spherical cap consists of a perfect spherical cap, which is therefore much larger than is the full male element. To be aware of the movement of "stomping" and the movement of "rolling" or "shin core" to approach is for the movement of stamping the solution very simple: the full spherical cap slides in its vertical position as the leg bends, at the same time to the rear, because the cavity containing it is spherical, so much larger, so that in As the bend takes place, the piece moves back slightly to the rear, in this way the to simulate rolling-sliding movement (pitching). As for the movement of the rolling or shin core, will this is realized in the following way: with the complete

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digen stretching Is the plug-in element in one of Blocked front-to-back recording, it is important to specify its shape; she is not rectangular but trapezoidal. The small base points forward and as the head rolls off and backs up, it widens as the groove is trapezoidal and moves sideways possible, and all the more so as the flexion increases: this is the "rolling" or "dangling". With such a In the scheme, the prosthetic device is mainly made up of a hollow sphere and a full sphere, which are articulated to one another without any other organ, without bolts, without screws. It It is sufficient to let the two pieces interlock in a flexible manner, they hold themselves.

The arrangement is as follows: the piece belonging to the leg represents the hollow receiving element, it is after open at the back along an arc of a circle whose diameter corresponds to that of the receiving element. This opening is in executed in such a way that the male element must be at right angles to the female element in order to penetrate this. It can only penetrate at a right angle in this position. From then on when it's in place it can no longer escape, at most when the position is established at right angles or around a few

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Minutes in this position (maximum 3 °) approximated what is impossible under the conditions of normal use, because above all the stretching device is blocked. There is so no risk of dislocation backwards. The plug-in element is the piece belonging to the shin bone that contains an attachment or process that extends into the The tibia can be driven in and on which a plate rests, which joins the surface of the tibia with a posterior one Adapts transverse spur and is supported on this. The essential elements of the tibial prosthesis are arranged underneath, namely an extensive, roughly prismatic paragraph, the base of which is trapezoidal, the large one Page goes from front to back and has two sides, namely a front and a rear, each vertical Side, and an upper side divided into two segments: the one front segment is oblique downwards and forwards and is united with the front side by a comb or stop, it is used to lock the prosthesis in the position of full extension, while the other posterior segment, which is the one described below G-joint element carries, two lateral elements do not has parallel trapezoidal sides, which serve as guide walls and here the lateral locking ensure in the extended position and allow lateral movements in the bending position and limit them here.

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The joint mentioned above rises above this irregular one Parallelepiped, whereby it first forms part of a spherical cap with an upper base which connects to a cylindrical segment that, to be precise, carries the spherical joint. These two spherical caps united by the cylindrical segment have two different centers in such a way that the length of the vertical axis of the whole is less than the theoretical diameter of the sphere. Just this is a very important characteristic for the mechanics of the type described above.

The receiving element contains a projection or extension which engages in the femur and which below of this carries the joint piece. This mainly contains a spherical cavity with a radius equal to that of the spherical cap of the plug-in element, which is accordingly larger on the side than the plug-in element with which it is articulated, from where the possibility of lateral movements and those from the front goes out to the rear (reset in the bend). Finally, below is where one of the main ones Characteristics of the prosthesis consists of having the cavity opened by a wide trapezoidal opening the small side facing forward. This opening is essential because it is the key to entry

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direction to maintain the prosthesis, it is decisive, it holds everything, it replaces all locking and locking systems that are found in the has proposed various prostheses. It is therefore necessary that precisely this is well thought out and well is expanded.

In the rearward and upward direction, this curved receptacle or opening expands to include a cylindrical one To form receptacle, the opening diameter of which is hardly larger than that of the cylinder piece between the insert element lying on both calottes ± & = fe ·. By this cylindrical passage, the opening of which lies in the vertical plane, penetrates when it is bent by 90 ° the articular head of the tibia, which is thereby held in its position, because from where the angle deviates more or less from 90 °, it can no longer be excavated. Starting out when moving from full extension one gets to the extent that the knee bends, thanks to the trapezoidal shape System on the one hand and through the combination of a ball and cylinder the joint surfaces on the other hand "sideways movements (rolling or dangling movements) and Movements for the return (of "stomping"). This system results in a movement which is the one approaches normal physiology and has an amplitude of 130 °.

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Another important advantage of this new prosthesis is that the loss of bone parts is minimal. This results from the surgical technique, the following is:

In practice, there are no particular difficulties, the incision applied is vertical, longitudinal towards the inside of the kneecap, allowing the entire extensor device to be twisted outwards. the The main points to observe are the following:

The surgeon must carefully expose the lower end of the femur, including the lower surface, this is very important because it is one of the support points for the prosthesis belonging to the thigh. The rear segment of the G-joint heads, which opposite protruding from the plane of this surface must be cut out completely.

You have to attack the bone in the cutout between the articular head, making all the lateral and anterior portions of the lower end of the femur should be left completely intact. Likewise, the Lower part of the joint heads belonging to the thigh minimally cut out (a few millimeters).

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The surgeon then prepares the axis of the thigh corresponding prosthesis, around which he hollowed out the bits of the piece belonging to the thigh, the is roughly cylindrical with about 3cm in diameter (3 - 4 cm in diameter). This! Table is elongated in your front part through the canal of the attachment or extension, but is guided laterally and behind or limited by a plane on which the prosthesis rests, which will fit into the back of the femur thanks to a small vertical spur or Insertion similar to that of the tibia.

When everything is ready, the surgeon tries on the prosthesis belonging to the thigh and makes sure that it is fits well in its storage.

The surgeon can only prepare the shin side after the piece belonging to the thigh has been well adjusted and fitted, move on to the shin piece. That Cutting out the shin in a vertical direction is more important. It must be a layer with a thickness of 1 cm or maybe a little more from the top of the tibia; the size of the clipping depends on. the injuries. Now and then there is one-sided, very "significant destruction or damage that is more extensive Condition to lose weight. This slimming will be after

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Determination of the position of the axis of the tibia carried out.

The surgeon then prepares the canal of the peg with a variable-caliber drill. Rear

in
He / it hollow out a ditch or a depression about 1 1/2 cm from this channel, which will serve for anchoring.

As soon as the two pieces have been used individually, he starts trying the whole thing. For this it is sufficient to place the leg at a right angle and the joint head on the shin side in his Place the prosthesis in position for the leg.

After the door has been prepared in this way, the whole material is renewed and the final layout of the pieces is carried out, which with a binding agent are attached from methyl methacrylate.

The invention can thus be defined as in a prosthetic direction for replacing a human knee joint realized, which is characterized by the fact that it is composed of two elements: on the one hand from an ο leren part of the leg and fitted into the bone receiving element, which with a

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Joint part is provided, the front wall of which is convex, and inside and behind it a cavity with a spherical outline "delimits, which is open downwards and backwards, and on the other hand from a lower male part belonging to the shin, which at its upper end with a joint part ends, which is formed by two connected by a cylindrical member spherical caps, said hinge portion of the male element can only be used in a position less than 90 ° in the spherical cavity of the belonging to the arm receiving element, but i _n all other positions included therein is held in such a way that a joint is formed which cannot loosen by itself, and in which the flexion-extension movements and also a slight lateral adjustment are permitted, which are necessary for the play of the joint.

This prosthetic device is generally characterized in that the spherical cavity of the thigh associated joint part is open to the rear and here an opening in the form of a circular arc with a The diameter is equal to that of the cylindrical Part of the plug-in element belonging to the shin is.

According to a special feature of this prosthetic device "the joint part of the male member contains a circumferential

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rich, roughly prismatic cones with trapezoidal ones Base, the large side of which runs from front to back and which has two pools, a vertical one front and a vertical rear surface, with the upper side of this pin divided into two segments is: the front segment runs obliquely downwards and forwards and is with the front side through one Comb or stop combines and serves to lock the device in the fully extended position, the other the rear part carries the joint part, which consists of two domes united by a cylindrical segment consists, whereby the two lateral trapezoidal, non-parallel surfaces of this .Zapfens form guides, which ensure the lateral locking in the extended position of the leg and it when bending allow, but limit, lateral movement of the knee.

According to another particular feature of this prosthetic device eich raises the actual joint piece above the pin in the form of an irregular parallelepiped and consists of a first spherical cap, which is divided by a cylindrical segment with a second spherical cap is united, these two domes being identical Have bulges, but they have different center points so that the vertical axis of the joint of the plug-in element * es

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is below the theoretical diameter of the sphere

According to another "unique feature" of this prosthetic device carries each of the two elements, viz. of the male element and the female element one protruding plate, the beyond the real. Joint lies, and a posterior tongue that is right-angled runs to this plate and which can be inserted into the bone-like part located in the middle in this way ensure a good attachment.

According to another unique feature of this prosthetic device contains, each of its two elements has a beginning or extension of the part belonging to the leg Middle part of the neck or the part belonging to the shin Enochenmittelstück is implantable. These extensions are outside the joint parts of the plug-in element and the Receiving element arranged and lie on the same Axis, whereby the prosthesis can be used just as well for the right as for the left leg. In the meantime, one can do them give an angle of 5 to 10 °, either on the side of the tibia or on the side of the thighbone, creating a right or left prosthesis

The approaches or projections of the two elements of the prosthesis are each in the bone marrow canals or in specifically in the thighbone and the shinbone

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Channels provided for the patient can be inserted.

The attachment of the approaches or appendages of the two Elements of the prosthesis in their receiving bores is preferably made with the help of an acrylic acid or cement Binder (methyl methacrylate) made.

The walls of the joint pieces of the male elements of the prosthesis are advantageously provided with thin layers of a lubricant such as, for example, Teflon ¹¹ , in order to avoid pitting or seizing.

In the drawing, an embodiment of the subject matter of the invention is shown. Show it:

Fig. 1 the two the device according to the

Invention forming elements in a disassembled exploded state seen from behind and in perspective,

Fig. 2 shows the device according to the invention

in the assembled state again seen from behind in perspective Depiction,

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3 shows the arrangement according to Pig. 2 in one

Front view and

4 shows the arrangement according to. Fig. 3 in a ^ n

Section along the line IV-IV of FIG. 3, the arrows indicating the joint movement demonstrate.

As can be seen from the drawing, the new knee prosthesis according to the invention consists of two elements: an upper, the receiving element 10 associated with the leg and having a joint part 11, the front wall 12 of which is convex and inside and behind the wall 12 a cavity 13 with a spherical shape Limited circumference, which is open downwards and backwards, and also a lower, the tibia associated plug-in element 14, which ends at its upper end in a joint part 15, which is formed from two spherical caps 16, 17 which are connected to one another by a cylindrical segment 18. This joint part 15 of the male element can only be inserted into the spherical cavity 13 of the receiving element 10 in a position below 90 ° However, it is held in all other positions within this recess as soon as it is plugged in has been, in such a way that in this way a joint is formed which by itself, cannot be released and at the same time the movements of bending, stretching and even

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with a slight lateral shift, which are necessary for the play of the joint.

The spherical cavity 13 of the joint part 11 of the receiving element is open to the rear, the opening running along a circle 19 with a diameter which corresponds to the cylindrical part 18 of the joint part (15) of the plug-in element. This articulation part 15 includes a substantially prismatic peg around f , with a trapezoidal base 20, the long side of which extends from front to rear, and with two perpendicular surfaces: a front surface 21 and a rear surface 22. The upper surface of this peg is divided into two segments: the front segment slopes downwards and forwards and is connected to the front 21 by a stop or comb, and it serves to lock the device in the fully extended position (position of full extension) , while the rear segment carries the joint part, which is formed from the two spherical caps 16, 17 connected by a cylinder segment 18. The two trapezoidal lateral surfaces of the pin formed in this way, which are not parallel to one another, form guides which ensure the lateral locking in the fully extended position of the patient's foot, while at the same time allowing lateral movements of the knee when bent, which however

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be limited at the same time.

The joint part 15 rises above the pin in FIG Shape of a prism and is formed by the spherical cap 16, which is formed by the cylinder segment 18 with the spherical cap 17 is connected, these two domes having identical curvatures (an identical curvilinear Course), but each with a different center are described so that the vertical axis of the male element formed in this way below the theoretical Diameter of the ball.

Each of the two elements 10 and 14 of this knee prosthesis device has a projecting plate 23 or 24, which is located on the other side of the actual joint, tmd at the rear in each case a tongue 25 and 26, which are at right angles runs to the protruding plate and can be inserted and inserted into the knee area behind it. can be used to ensure a good fixation of this joint part.

The two elements 10, 14 of this knee prosthesis device have extensions, attachments or protruding parts 27, 28 provided, on the one hand in the bone center piece or in the marrow canal of the leg and on the other hand in the middle of the bone on the other side of the tibia

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the joint part of the receiving member 11 or the male member 15 can be used.

The extensions or lugs 27, 28 of the two elements of this knee prosthetic knee device are in cavities in the marrow canal or in cavities that are specially designed for this purpose in the thigh bone or has been provided in the patient's splint are, pluggable and insertable. The attachment of the Projections or protruding parts 27 »28 of the two elements 10, 14 of the knee joint prosthesis device in the recesses receiving them will prove to be advantageous with the help of an acrylic binder or cement (Methyl methiacrylate).

The walls of the articulations of the elements 10 and 14 of these Knee joint prosthesis devices are advantageously provided with small layers of a lubricant, e.g. Tetrafluoroethylene known commercially under the name "Teflon" provided to prevent any seizure.

The way of using and inserting this new knee joint prosthesis device in the area of the knee of the Patients has already been described in a previous section of the present text.

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The individual parts of this joint prosthesis device can be made of plastic material or entirely of metal or of a non-oxidizable alloy, depending on each of the clinical applications and the implementation possibilities "are established during the operation, wofcei these details in the area of technical equivalents can be changed without going out of the area the invention came out.

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Claims (9)

Expectations y 11 s replacement for the prosthetic device serving the human knee, characterized in that that it consists of two elements, namely on the one hand an upper one, assigned to the leg Receiving element which is provided with a hinge part with a convex front wall, which for this purpose serves to support the human kneecap, with a cavity inside and backwards from this wall is formed with a spherical periphery that is open downwards and backwards, and other on the other hand from a lower, the Sphienbein assigned plug-in element, which at its upper end in a Joint part ends, which is formed from two spherical caps, which are connected by a cylinder segment are, the hinge part of the male element only in a position below 90 ° in the spherical Hollow of the receiving element assigned to the leg can be used, but in all others Postures are held in this cavity after insertion in such a way that a hinge is formed, which cannot be released by itself and at the same time the movements for bending and stretching as well A slight lateral adjustment movement is permitted, i.e. all movements are necessary for the play of the joint are. 309829/0460 - 25 - 2. Apparatus according to claim 1, characterized in that the spherical cavity of the receiving element to the rear about an approximately circular in circumference Opening opens, the diameter of the circle being equal to that of the cylindrical segment of the male element is. 3. Device according to claim 1 or 2, characterized in that that the joint part of the plug-in element has an extensive pin of essentially prismatic shape Has a shape with a trapezoidal base, the long or large side of which extends from front to back and which has two faces, namely a front and a rear face, both of which are perpendicular, being the surface of the pin is divided into two segments: the one front segment runs obliquely downwards and near the front and is connected to the front by a stop or comb and serves to move the device into the Able to lock while in full extension the other rear segment carries the joint part, which consists of two spherical caps connected by a cylinder segment consists, the two non-parallel trapezoidal lateral surfaces of this pin guides that ensure the lateral locking in the position of the complete extension of the foot, and at the same time the lateral evasive movements when bending 3098 29/0460 - 26 - of the knee, but at the same time "limited will. 4-. Device according to claim 3 »characterized in that the actual joint piece is located above the pin extends in the shape of an irregular parallelepiped and contains a first spherical dome which passes through a cylindrical segment is connected to a second spherical dome, these two dome being identical Have bulges or curvilinear curves, but which have been described from different centers, so that the vertical axis of the joint head of the male element is below the theoretical diameter of the Ball lies. 5. Device according to one of claims 1 to 4-, characterized characterized in that each of the two elements, namely the male element and the female element, has a protruding one Has plate, which is provided on the other side of the actual joint, and also one on the! back has provided tongue, which runs at right angles to this plate and into the one behind it Bone part can be inserted and used for good fixation. 6. Device according to one of claims 1 to 5 _S thereby 309829/0460. 27 - characterized in that each of the two elements has an extension or approach, which in each case in the middle part of the thigh bone (or in the bone marrow canal) and into the midsection of the tibia can be inserted and is provided on the other side of the joint part of the two elements. 7. Apparatus according to claim 6, characterized in that that the extensions or approaches of the two elements each in cavities in the bone marrow canal or in particular for this provided cavities in the thighbone and in the shinbone of the patient can be inserted. 8. Apparatus according to claim 7> characterized in that that the attachment of the projections or approaches of the two elements in the cavities that serve to accommodate them, advantageously with the help of an acrylic cement or binder (Methyl methacrylate) is made. 9. Device according to one of claims 1 to 8, characterized in that the V / ands of the joint heads of the two Elements are each provided with thin layers of a lubricant, such as "Teflon", which serves to prevent jamming or seizure. 309829/0460 ORIGINAL INSPECTED