JPS58152557A - Artificial joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is in the field of implantable artificial joints.

Various types of artificial or prosthetic joints are known. The stability of a full joint prosthesis is a trade-off between the bioengineering designed by Katakasumi and the existing anatomical structure. Cl1a, Qrth,
and Rel, R@g, 144 (1979) p.
Forcibly constrained prostheses, such as those presented in the 185 M, Po5t et ml paper, create significant forces and pressures within the bone-cement-prosthesis interface, which can lead to loosening or dislodgement of the device itself. It is something to be feared. J, BIomedlCng.

Vol. 1, p. 252j (1976),
A, V, 5w1n@on The unrestrained prosthesis shown in the paper is prone to dislocation.

Artificial joints based on magnetic interaction have been previously attempted. For example, J.
inssen et a1 name US-Pg4.024.
588 (column 2, lines 22-26) indicates a prosthetic joint with a concave and convex inset member structure, which includes at least one inset for providing mutual rotational or translational movement about the pivot point at those members. It is equipped with a magnet.

This magnetic force may be either attraction or repulsion. These patent holders have achieved a B rating for their achievements in these fields.

0rtbo9. ILS (1975) pp-40040
1tc is also shown.

As such, the prosthetic joint shown in US-Pg 4.024.588 has some concomitant effects since the lines of force of the magnetic field pass directly along the axis or direction of movement of the inset member of the indentation. It has certain drawbacks. The abutting areas between these interlocking members are exposed to considerable pricking forces, which can result in considerable abrasion caused by magnetic lines of force. If repulsive magnetic forces are used, these joint members may become suspended and eventually dislocated. If attractive magnetic forces between these parts are utilized, such prosthetic joints can result in inelastic shock transmission along the skeletal structure, further aggravating skeletal injuries and making them more likely to dislocate. belongs to. In fact, even U8-Pg 4.024.588 itself is 2 column 2
This is a problem acknowledged in lines 9-40.

Therefore, one object of the present invention is to provide an artificial joint for implantation in a living body that has minimal complexity in appearance and articulation system.

Another object of the present invention is to provide an artificial joint based on magnetic attraction, in which the magnetic attraction between the two joint members improves the stability and integrity of the artificial joint without hindering the movement of the joint members. It is to provide something that preserves one's sexuality.

Still another object of the present invention is to provide an artificial joint based on magnetic attraction between two joint members, in which the degree of freedom of movement of both joint members closely resembles that of the original joint to be prosthesized. The goal is to provide the following.

Various other objects of the invention will become apparent from the content of this specification.

The present invention is an artificial joint for implantation into a living body, which comprises two members or pieces that are brought together by attractive magnetic force. A magnet is housed in one or both of these pieces, and its lines of magnetic force run across the direction of movement of the pixel pieces (perpendicular to the axis of rotation of the pieces). Although the artificial joint is firmly held in position by an attractive magnetic force, such force does not impede the freedom of movement of the artificial joint pixel pieces. Thus, the need for external coupling means such as pins, hinges, etc. is effectively eliminated from the prosthesis of the present invention. If necessary, these artificial joints can be separated with minimal force during surgery.

The artificial joint of this invention can effectively replace any natural joint in vivo. In one embodiment, such a joint prosthesis includes two pieces that fit together in a fitting as shown in the accompanying drawings. Although such artificial joints can be placed in any of a number of locations within the body, they are particularly suited for replacing elbow and finger joints. The invention will now be described in more detail with reference to the accompanying drawings. The following description is not intended to limit the scope of the invention or its embodiments.

, Figures 1 and 2, 5i! The example includes two pieces (3) and +B+. The first piece is equipped with a shaft material (flO), which has two bipartite parts (river) at one end.

0tIK branched. If you look more closely, you can see that the shaft material starts to spread out at both corners (■, ■) to the p step part α, and the base further branches into two parts (river, 02). As shown in the figure, these parts are equipped with K, each side G, (to). are both sides of the shaft material θ barrel, αIK are substantially parallel, and both sides of the base section widen at the end ■, @ extend diagonally between those two parts and such sides of the shaft material. Furthermore, the ceiling surface @ and the bottom surface (23) (not visible in Fig. 2) of the shaft material tlol are connected to both sides (18) and (I) of the shaft material Oa.
Together with n, this embodiment shown in the figure creates a pivot axis of approximately square cross section. However, the shaft material of such a piece or another piece (B1) is round,
It may be shaped in any desired cross-section, such as triangular, diamond-shaped, triangular, hexagonal, etc. In addition, the sides and edges of the shaft material may be wavy, jagged, textured, etc. to assist in anchoring the shaft material to the bone tissue with the acrylic bone cement.

As mentioned above, both sides of the base part t11 of the shaft material □
□□, (company) [starts at corner ■, (2)]
It extends obliquely between both sides of the shaft and the lid and both parts (river, 1121), giving rise to an approximately triangular external shape of the base part Cl31 that widens at the end, as shown in Fig. 2. Furthermore, throughout the rest of the shaft material 101, it extends approximately parallel to the ceiling surface of the shaft material (111) and the bottom surface (C). There is a slight curvature.

This is done so that the central axis of the shaft material is parallel to the central axis of the bone into which it is fitted, such as the humerus. This is clearly shown in Figure 1, which is a side view.
) and K are smooth. This formation is the same for the Futamatadai part (river), which is hidden in the diagram.

H itself may take any suitable shape. The lid and base portion in the embodiment shown in the figure is similar to that shown in FIG. 2 which is a top view.
, is approximately cylindrical in shape. Straight K, shaft material +I
In the widening base part 01 of Q, between the lid and the two parts, there is a recessed inner recess shown in dotted lines in FIG. 1 and clearly shown in FIG. The purpose of this recessed portion is to receive the pixel piece (B1) neatly when the pixel piece (B1) is engaged with the pixel piece (B1).

The second piece (Bl is equipped with a shaft material ω, which is formed into an enlarged head 61 at one end), which head has two side faces 1, al and 61 as shown in the figure. This is from Menbubi. Similarly to the above, the shaft material ω may take any suitable shape. In this embodiment shown here, both sides 53, 61 and both sides of the ceiling and bottom (to) create a shaft member with a substantially square cross section. Furthermore, both the ceiling and bottom surfaces of the shaft material, ω, (to), are slightly curved for attachment to the target bone tissue, but these surfaces may be completely straight or of any suitable shape. But that's fine.

The head of the shaft material ω of the elementary piece @) is also shaped like a cylinder. When B) are interlocked, an interlocking part of the pixel piece (31 head r51it;
K fits nicely into the inward recess between α and K. Figure 4A-48 is a piece prisoner, (B
) shows two possible meshing positional relationships. The elemental pieces in Figure 4A (B) are inverted and interlocked at a certain angle K, while the elemental pieces in Figure 4B (B)
) is in the fully extended position. In general, the radius of curvature of the concave part (goods) of the fragment prisoner is slightly larger than the radius of curvature of the head (511) of the fragment fBI, and
The width of the cylindrical platform part 611 of Bl is slightly smaller than the gap between the two cylindrical parts of the fragments (river, side view of Oa, and the ends), and these fragments are interlocked. The degree of movement between the pixel pieces of this joint varies from 09 when the pieces are fully extended to complete folding (for example, in Figure 4B). (see dashed line), which lasts for K until approximately /3 o'clock.Furthermore, the elementary piece (B
The fact that the width of the head circumference of L is slightly smaller than the gap between the lid and the stand of the pixel of the pixel of the pixel of the artificial joint allows anterior and posterior flexibility between the pixel of the artificial joint.

Thus, such an artificial joint of the present invention includes an elbow joint,
The movement of finger joints and other various joints in the living body! It is something that can be closely imitated by lK5.

The components of the artificial joint of the present invention may be made of any suitable material that can be injected into the body, such as aluminum, polymethyl methacrylate, V-recon rubber, or cobalt chromium. The preferred material is 8
16L stainless steel, cobalt, chromium, molybdenum (MaI)
tallium, orth-ochr(2), xl
commercially available as malloy), and titanium (
Tl-6kt-4V alloy).

The aluminum joints of this invention may be prepared using conventional machining methods, while the cobalt chrome joints are preferably constructed using lost wax construction and precision cast.

In the example shown in the figure, the lid of the elementary piece prisoner has nine parts (river,
(+1 is each inserted magnet (10G).

(110), and the heads of all the elementary pieces (Bl) similarly have magnets (105). Magnets (100), (1
05) and (110) are approximately cylindrical, but may have any suitable shape. These magnets may be constructed of any permanent magnetic material such as cobalt samarium (CosSm), cobalt rare earths, or high energy product permanent magnetic materials. A preferred magnet material is C05Sff1.

The magnets are fitted (for example, Figures 1 SA-111) and held in place with a suitable adhesive 9, which further effectively encases and protects them from wear and other damage. Suitable enveloping materials include polyethylene, medical grade Evoki V, (medical grade) V recon rubber, etc., with particularly preferred enveloping materials being Evoki V based compounds or high molecular weight polyethylene.

Additionally, the magnet may be laminated with a polyethylene filler material prior to wrapping.

Figure 6B shows the futamatata part (the magnet (l) within the fragment).
The magnet is first laminated with polyethylene inserts (180), (180). In other words, the polyethylene filler material (120) and (110) are the nine parts + In.
This means that the outer wrapping material r140 and (16G) are applied to both sides of +III and (17+, respectively) before being applied. The hollow part in the elemental piece is preferably
It is preferable that all the magnets in this artificial joint be covered with high molecular weight polyethylene to prevent unnecessary abrasion of the tube due to contact with the above-mentioned surface of the head of the element (Bl). They are protected from contact with each other, contact with other parts at the interlocking part, and contact with external biological tissue, and only the emitted magnetic lines of force affect the IK of the artificial joint. So it has.

The magnets (100), (110) in the alternative 'J' embodiment (shown in cross-section in Fig. 5i) are located at the base part (it) of the element (4), ( It does not span the entire convergence of each lid, but is located in a hollow hole drilled into the inside of the lid, and the bottom of the hollow hole -1- is located within the nine parts of the lid. The side rma @ (terminates near 1 o'clock).
1! It is only necessary to hold and seal the position with outer wrapping materials (160) and (17G) at the outer side surface or end surface 64.11η of +, respectively. Therefore, the lines of magnetic force still pass through the inner walls (l@, (1-) of the pedestal part.

Therefore, the magnetic effect of this type of embodiment is the same as in all other embodiments of the invention, and the magnetic force is hardly reduced or inhibited.

The magnets are positioned such that when one pixel piece is brought into cooperating engagement within one artificial intersegment piece, an attractive force is created between them. These magnets are located at the futamata base part (11) inside the elemental piece (1!!) and the head of the elemental piece (B) (
It is made of stone and has pixel fragments inside.
When they are brought together on one side (for example, see Figures 4A and 4B), attraction occurs between them, and when one or the other of the pieces is turned tightly, repulsion occurs.

Therefore, the polar arrangement of the magnets inside this artificial joint is difficult to assemble and engage if one pixel is open and (B) is in the wrong direction. It may be removed from either the lid or the base part, or from the head 6υ of the elemental piece (B). In short, it is sufficient as long as a suction force is generated when the elemental pieces are engaged ( The magnets may be replaced by ferromagnetic materials that respond to the attraction of other magnets).

Within such a prosthetic joint, the magnets are placed in the pixel opening and transverse to the axis (i.e., the direction of pivoting) of their consonance (i.e., the direction of pivoting) when Bl is assumed to be in cooperating engagement, i.e., perpendicular to it; It is positioned so that the lines of magnetic force flow through it.

As a result, the magnetic force restraint brought about by the attractive force between the magnets of the pixel piece only works against the displacement of the elemental piece of this artificial joint,
The bending or extension rotation as they pivot around the cooperating mesh does not interfere with rotation. In this way, the artificial joint of this invention brings about the reduction and addition of muscles and ligaments at the artificial joint, and improves the in-vivo muscle and ligament.
It provides improved stability and integrity to the skeletal structure.

The embodiments shown in these figures are particularly suitable as artificial elbow or finger joints. In the artificial elbow joint, the humerus bone fragment is inside the fragment, and is intended to be inserted into a recess formed in advance in the humerus. The distance between the shaft members of the piece (5) has a length from IOC'llll to 7.21 and a cross-sectional area from cod to /dfi. The diagonal side surface of the base part 0'4 that spreads out towards the end -0 beam has a length of about 11 to about 2.53 fi, and its peripheral side and central side (■), has a width of approximately 0. '7!
;3 to about 0.2!31, and both medial aspects (country, 0
The gap between - is about o, from rsas to about /, 03
The approximate radius of the inner recess 124 is from about /1 to about /, and the approximate radius of the inner recess 124 is from about /1 to about /,
The book has a radius of curvature of up to .

The center of the lid t9 cylindrical platform part (o), t) i is the beginning of the p platform part 2, that is, the beginning of the p platform part, that is, both sides -, η corresponds to both sides of the shaft member, (II When it sinks in,
In other words, it is deviated from the axis of the shaft material by about J~/0", preferably by 7 degrees, when viewed from both corners. In order to say that the external shape of the fragmentary prisoner perfectly matches the physiological external shape of the humeral process to be replaced, K.
That's why.

The base part can be made with a piece of shaft material (In), or it can be made separately and then made with a suitable adhesive. It may also be assembled to an Al shaft material.

The piece (Bl) is an ulna piece, which is prefabricated inside the ulna and is intended to be inserted into the nine recesses. and has a cross-sectional area from about /- to about /, sdi.The cylindrical expansion head (2) of the element (B) is about /1
a radius from about 0.7 j to about 0.2 j1, i.e. an inward recess in the lunar tAl to allow for natural anteroposterior flexibility - slightly less than It has a wide range. Furthermore, the radius of the head (9) is slightly smaller than the radius of curvature of the medial recess to allow more freedom in the animation of the ulnar segment.

In this example, if the artificial elbow joint /~/33' (±50 is derived from the internal hit point) can be completely rotated, and if a smaller rotation is desired, then (An abutting part (156) may be provided along the Oa+ of the decoy. These two ★embodiments are the sixth embodiment.
They are shown in Figures A and 61 respectively. Furthermore, in order to prevent unnecessary wear and tear between the joint pixel pieces, it is preferable to attach or fit a high molecular weight polyethylene layer to such surfaces of the inner concave portion A4 of the pixel pronation.
The joint disengagement force at full extension (Oo) of this elbow joint is approximately 3#, which is sufficient to support the forearm without any load on it.

The distal lid portion (■) of yet another embodiment of the elbow joint (see FIG. 7A) is provided with a medium-high protrusion extending outward and forward. This lateral forward projection □□□ is preferably brought into articulation with the radius in the body by abutting against a polyethylene insert in the radius at its end surface (to).
has been done. The polyethylene insertion material shown in Fig. 71, which is a cross-sectional view, is equipped with a polyethylene backing and a shaft member with a nine-headed shaft, which is similar to the conventional bone prosthesis insertion material. It is inserted into the radius bone by some technique. Thus, in place of such inserts as shown in the figures, a complete solid polyethylene piece may be used in this particular embodiment.

It provides excellent stability at the elbow joint, especially at the joints of the humerus and radius.

As previously mentioned, the embodiment shown in the figures is also suitable for finger joint replacement.

In such a case, the shaft material DI of the fragment prisoner has a fear of approximately ko~33, and is 0.2 from /d! This is a book with a cross-sectional area at t41. Diagonally both sides of the base part 11, the length of the phantom is about 0.73 DIR to about /, 0 CI
There is up to I, and the cylindrical futamata platform part (river.

(The radius of I!0 is from about o, paa to about 0.33, and the edge rlfJ@, ya of the Futamata base part has a width from about 0.23CM to about 0.33cm. Futamata White flesh part CI+), the sag between the inner 11-face and rectangle of 02 is from about 0.31 to OJ3, and the approximate radius of curvature of the inner recess - is from about 0.4t3 to about 0. Up to 33. The length of the elemental piece (B) is approximately /1
to about 7.3 aI and about 0.73 d to about O, with a cross-sectional area of shaft material -1 from about 0.73 d to about O, Kojdi.

Cylindrical gI in elemental piece fB)! Iυ is approximately 00tIaIl
to about O,S3''! and a radius from about 0.23 CIl to about 0.II3, ie, slightly less than the width of the medial recess in the gyrus.

Although some preferred specific embodiments are described above and shown in the drawings, the shape and material of such prosthetic joint pieces and the shape, material or type of magnets may vary depending on the respective joint in vivo. It can be modified in various ways to approximate the actual results. Therefore, the foregoing description of the preferred embodiments is not intended to limit the scope of the invention.

[Brief explanation of the drawing]

Figure 1 is a right side view of the artificial joint structure according to the present invention, which is equipped with two pieces (A) and (B), with the color removed, and Figure S is a side view of the artificial joint structure shown in Figure 1. A color peeled top view, Figure 3 is a cross-sectional view of the artificial joint of this invention according to line 1 in Figure 8, and Figures 4A and 4B are two views of the artificial joint in which the pixel pieces are engaged. Possible shape OI
The first view and both figures 5A and 5B are cross-sectional views of the modified mounting state of the magnet in the artificial joint, and both figures 8A and 6B are sectional views of the artificial joint.
FIG. 7A is a partial side view and a top view of each modified example of the fragment (B) of the artificial joint, and FIG. 78 is a partial top view of another modified example of the artificial joint fragment. The figure is a sectional view of a component for abutting the tortoise joint of such a modified example of the elemental piece prisoner. Prisoner...--First elemental piece, (B)...Second elemental piece,
01...Shaft material of fragments, C11! , (
+fi...Futamata part, 0 place...End wide base part, +141~(21)...@ surface, field...Ceiling surface, camp ...Bottom, (goods)...
...inner recess, -, W... end face, @...
・・・External anterolateral color projection, (to) ・・・End face, -0
@0... corner, throat, 偲υ... kuhomi hole, -9 angle... bottom, luster... piece (Bl shaft material) Material, 6 tons... Enlarged head, U, 641...
...Side surface, (to)...Ceiling surface, (to)...
・・Bottom surface, −・・・・End surface, (to), (to)・・
...Side surface, ■...--Polyethylene radial bone insertion material, 61)...Polyethylene-backed head, -
・・・・・・Metal handle shaft material constituting the insertion material, (10
0), (105), (110)... Magnet,
(120). (180)...Filled polyethylene material, (1
40). r150)...Outer wrapping material, (156)...
...Abutting stepped portion, (160), (170)...
...outer wrapping material.

Claims (1)

[Claims] ■ An artificial joint comprising the following components (A-B-C). A) A first elemental piece. B) A second elemental piece that cooperatively engages with this first elemental piece, which has an engaging part in which these pixel pieces pivot. C) These a magnet disposed within at least one of the pixel strips, the magnetic field lines of which flow substantially transversely to the direction of pivoting of the pixel strips, such that they attract each other when the pixel strips are brought into cooperative interlock; (1) The artificial joint according to claim 0, wherein each of the pixel pieces is provided with a magnet. (2) The first element piece cooperates with the second element piece to engage with the artificial joint. The artificial joint according to claim 0, which has a recess for receiving the receiver. ■ The artificial joint is close to the recess at the ninth point of the first element,
Artificial joint according to claim 0, in which at least one magnet is arranged. (2) The artificial joint according to claim 0, wherein magnets are arranged on both sides of the recessed area. (2) The artificial joint according to claim 0, wherein a magnet is disposed within the second piece. (2) The artificial joint according to claim 0, wherein the joint is an elbow joint. (2) The artificial joint according to claim 0, wherein the joint is a finger joint. (2) The artificial joint according to claim 0 or 0, which satisfies both of the following substances (A-B). A) The first piece has a shaft that is bent at one end. B) The second piece is provided with a handle shaft member, and one end of the handle shaft member has an enlarged portion for cooperative engagement with the recessed part of the first piece. 0 The handle shaft material of the first elemental piece is hollowed, and both sides of the nine points are enlarged parts to receive the enlarged parts of the second elemental piece, and the recesses thereof. The artificial joint according to claim 0, wherein the attached portion is slightly larger than the enlarged portion of the second element. 0 The artificial joint according to claim 0, wherein the first elemental piece is formed to be fixedly assembled to a humerus in a living body, and the second elemental piece is formed to be fixedly assembled to an ulna in a living body. . (2) The artificial joint according to claim 0, wherein magnets are arranged on both sides of the handle shaft of the first piece. @ The artificial joint according to claim 0, wherein a magnet is disposed in the enlarged portion of the handle shaft member of the second piece. (2) The artificial joint according to claim 0, wherein magnets are arranged in all enlarged portions of the handle shaft material of the second pixel piece. O The enlarged distal part of the first piece is a living Japanese cypress. Claim 0, which further includes a protrusion for contacting the bone, thereby increasing the stability when the pieces of the artificial joint are brought into cooperative engagement. Artificial joint. ■ The enlarged part of the handle shaft material of the second pixel piece is substantially cylindrical, and the recessed part of the first element piece receives the enlarged part of the handle shaft material of the second element piece. A joint prosthesis according to claim 0, wherein the joint prosthesis is substantially curved for insertion.