MEDICAL ARTHRODESIS IMPLANT

Abstract

The medical implant (1) according to the present invention comprises a first, generally elongate portion (20) extending along the longitudinal axis A, intended to be inserted into the first bone (P1) and comprising first attachment means (24), and a second, also elongate, portion (30) following another longitudinal axis B, intended to be inserted into the second bone (P2) and comprising second attachment means (34), wherein said first and second portions (20, 30) are connected together via a connecting bridge (40) which is centered about the orthonormal axes X, Y, Z of said implant (1), providing for at least one axial offset of the second portion (30) with respect to the first portion (20) such that the longitudinal axis B of the second portion (30) is positioned in at least one direction forming an angle () relative to the longitudinal axis A of the first portion (20) and is offset by at least a certain distance along at least one of the axes XX, YY and ZZ of the connecting bridge (40) in order to avoid any offset between the outer upper portions of the first bone (P1) and the second bone (P2).

Claims

1. Medical implant (1) intended to allow bone fusion between a first bone (P1) and a second bone (P2), the said implant comprising a first, elongated part (20), extending along the longitudinal axis A, intended to be inserted into the first bone (P1) and comprising first attachment means (24) and a second, also elongated part (30) on another longitudinal axis B, intended to be inserted into the second bone (P2) and comprising second attachment means (34), said first and second parts (20, 30) being connected by a connecting bridge (40), characterized in that the said connecting bridge (40) is centered around orthonormal axes X, Y, Z of the said implant (1), creating at least one axial offset of the second part (30) with regard to the first part (20) so that the longitudinal axis B of the second part (30) is positioned in at least one direction, titled at an angle () with regard to the longitudinal axis A of the first part (20), as well as offset by a length of at least one of the axes XX, YY, and ZZ of the connecting bridge (40) to prevent the creation of an offset of the upper exterior parts between the first bone (P2) and the second bone (P1).

2. Medical implant (1) according to claim 1, characterized in that the longitudinal axis B of the said second part (30) is offset by a distance (D.sub.s1) equal to the length of axis YY.

3. Medical implant (1) according to claim 1, characterized in that the longitudinal axis B of the said second part (30) is offset by a distance (D.sub.s2) equal to the length of axis ZZ.

4. Medical implant (1) according to claim 1, characterized in that the first part (20) is in an elongated shape and comprises at least three brackets (21, 22, 23) each respectively extending along the longitudinal axis A and including a distal end (20A) and a proximal end (20b).

5. Medical implant (1) according to claim 4, characterized in that the brackets (21, 22, 23) are regularly arranged around the longitudinal axis A, providing a space to drill a bore hole or canula (25) between the said brackets and in the body of the first part (20), supported by longitudinal axis A and crossing the connecting bridge (40) allowing the guide pin to fit through.

6. Medical implant (1) according to claim 4, characterized in that each bracket (21, 22, 23) comprises attachment means on its outer edges, made of hooked notches (24), creating a toothed external profile all along the first part (20). The said hooked notches (24) each have an edge (24a) pointing toward the connecting bridge (40).

7. Medical implant (1) according to claim 1, characterized in that the second part (30) is extended and comprises at least three brackets (31, 32, 33) each respectively extending along longitudinal axis B and comprising a distal end (30a) and a proximal end (30b).

8. Medical implant (1) according to claim 1, characterized in that the longitudinal axis A of the first part (20) cuts the longitudinal axis B of the second part (30) in a point of intersection I.sub.3 located between the distal end (20a) and the proximal end (20b) of the said first part (20).

9. Medical implant (1) according to claim 4, characterized in that the point of intersection I.sub.3 is located at a distance L.sub.3 from the proximal end (20b) and a distance L.sub.3 from the distal end (20a) of the first part (20).

10. Medical implant (1) according to claim 1, characterized in that the orthonormal axes X, Y, Z of the connecting bridge (40) intersect at a point of intersection I.sub.2.

11. Medical implant (1) according to claim 5, characterized in that the point of intersection I.sub.2 is located a distance L.sub.2 from the proximal face (30a) of the second part (30).

12. Medical implant (1) according to claim 1, characterized in that the vertical axis D of the connecting bridge (40) intersects the longitudinal axis B of the second part (30) at a point of intersection I.sub.1 is located at a distance D.sub.s1 from the point of intersection I.sub.2.

13. Medical implant (1) according to claim 1, characterized in that the longitudinal axis XX of the connecting bridge (40) can coincide with the longitudinal axis A of the first part (20).

14. Medical implant (1) according to claim 1, characterized in that the longitudinal axis XX of the connecting bridge (40) is titled with regard to the longitudinal axis A of the first part (20).

15. Medical implant (1) according to claim 1, characterized in that the connecting bridge (40) is surrounded by two opposite faces (40, 41) that coincide respectively with the distal end (20a) of the first part (20) and the proximal end (30b) of the second part (30).

16. Medical implant (1) according to claim 2, characterized in that the distance (D.sub.s1) is less than or equal to 20 millimeters.

17. Medical implant (1) according to claim 3, characterized in that the distance (D.sub.s1) is less than or equal to 10 millimeters.

Description

[0033] The description below regarding the drawings attached, given only as examples, will help better understand the invention, its characteristics and the advantages it has:

[0034] FIG. 1 is a perspective view that illustrates the medical implant according to this invention.

[0035] FIG. 2 is a front view showing the medical implant according to this invention.

[0036] FIG. 3 is a cut view showing the medical implant according to this invention.

[0037] We showed in FIGS. 1 to 3 a medical implant 1 according to the invention which would allow the creation of an arthrodesis in order to connect and fuse two adjacent phalanges between them, called proximal P1 and distal P2.

[0038] The medical implant according to the invention 1 is preferably a one-piece unit. It can be made, for example, by injecting molding or cutting. The medical implant 1 can be made of a biocompatible material, metallic or not. For example, this material can be chosen from polyaryletherketones (PEEK or PEKK), titanium, stainless steel, polylatic acids and their mixtures.

[0039] The implant 1 comprises a first part 20 and a second part 30 meant to be respectively inserted in the medullary canal of the proximal phalange P1 and the distal phalange P2, the said first and second parts 20, 30 being connected to one another by the connecting bridge 40 centered around the orthonormal axes X, Y, Z of the said implant 1.

[0040] The first part 20 is extended, including a distal end 20a and a proximal end 20b. The first part 20 has a longitudinal axis A intended to be aligned, or coinciding with, when inserted into the longitudinal axis of the medullary canal of the proximal phalange P1.

[0041] The first part 20 comprises at least three brackets 21, 22, 23 each extending respectively along the longitudinal axis A and from the distal end 20a or the connecting bridge 40. Brackets 21, 22, 23 give the first part 20 an overall star-shaped cylinder shape.

[0042] In the example shown, the three brackets 21, 22, 23 extend in parallel one over the other. In an embodiment not shown, the brackets 21, 22, 23 can extend based on the respective axes that are slightly separate from the longitudinal axis A.

[0043] The brackets 21, 22, 23 are regularly placed around the longitudinal axis A, making it possible to drill a bore or canula 25 between the said brackets and in the body of the first part 20, supported by the longitudinal axis A and crossing the connecting bridge 40 for a guide pin to fit and be able to better handle and guide the implant 1 during its insertion.

[0044] The bore hole or canula 25 also makes it possible to insert an osteo-integration activator in the implant 1.

[0045] According to the invention, each bracket 21, 22, 23 has hooked notches 24 on its outside edges which creates a toothed outer profile on the whole length of the first part 20.

[0046] The hooked notches 24 are the first attachment means intended to hold the first part 20 of the implant 1 in the proximal phalange P1 in which the implant is meant to be inserted.

[0047] The hooked notches 24 each have a ridge 24a pointing toward the connecting bridge 40, which makes it possible to improve the fixation and holding of the first part 20 inside the medullary canal of the proximal phalange P1.

[0048] The second part 30 is elongate, comprising a distal end 30a and a proximal end 30b. The second part 30 is intended to be inserted in the medullary canal of the distal phalange P2 adjacent to the said proximal phalange P1.

[0049] The second part has a longitudinal axis B meant to be aligned, or coinciding with, the longitudinal axis of the medullary canal of the distal phalange P2.

[0050] The second part 30 comprises at least three brackets 31, 32, 33 each extending respectively along the longitudinal axis B and from the distal end 30a or the connecting bridge 40.

[0051] The brackets 31, 32, 33 each give the second part 30 a slightly conic star shape. In the example shown, the three brackets 31, 32, 33 extend in parallel over one another and in the alignment of the brackets 21, 22, 23 of the first part 20. In an embodiment not shown, brackets 31, 32, 33 can extend along the respective axis, slightly separating from the longitudinal axis B.

[0052] According to the invention, each bracket 31, 32, 33 includes on its outer edges the hooked notches that create a toothed external profile all along the second part 30.

[0053] The hooked notches 34 are the second attachment means intended to hold the second part 30 of the implant 1 in the distal phalange P2 in which the implant is meant to be inserted.

[0054] The hooked notches 34 each have a ridge 34a pointing toward the connecting bridge 40 which helps better fix and hold the second part 30 inside the medullary canal of the distal phalange P2.

[0055] The direction of the hooked notches 24 and 34 of each first and second part 20, 30 respectively pointing toward to the connecting bridge 40 makes it possible when inserting the implant 1 to more easily bring together the proximal P1 and distal P2 phalanges to fuse them together.

[0056] The connecting bridge 40 is centered around the orthonormal axes X, Y, Z, which allows the bridge to have an axial offset of the second part 30 with regard to the first part 20 of the implant 1. The axes do not intersect centrally. Because of this and to adapt to the anatomical needs, the implant is bayonet-shaped.

[0057] The connecting bridge 40 may allow different axial offsets, combined or not, in order to position the second part 30 with regard to the first part 20 in different geometrical planes, which can be combined. The axes are offset with regard to the center of the joint.

[0058] This embodiment of the implant 1 makes it possible to offset the distal phalange with regard to the proximal phalange toward the inside or outside of the foot or hand and thus to respectively adduct or abduct it. This embodiment is particularly advantageous for treating a Hallux Valgus.

[0059] The connecting bridge 40 is surrounded by two opposite faces 40, 41, which, depending on its geometric profile, could respectively coincide with the distal end 20a of the first part 20 and the proximal end 30b of the second part 30.

[0060] In the embodiment example of this invention, the profile of the connecting bridge 40 makes it possible to position the longitudinal axis B of the second part 30 in a first direction which is titled at angle with regard to the longitudinal axis A of the first part 20.

[0061] Angle may vary by about 0 to 25, for example from 10 to 20, preferably 10. It is possible to vary the angle , in particular to adjust the implant from the invention to the anatomy of the human body part to treat, for example, the foot or the hand.

[0062] Also, the profile of the connecting bridge 40 makes it possible to position the longitudinal axis B of the said second part 30 in a second direction, which is offset by a distance D.sub.s1, with regard to the longitudinal axis XX of the said connecting bridge 40.

[0063] In our example, the distance D.sub.s1 runs along the axis YY. Depending on the profile of the connecting bridge 40, it is also possible to position the longitudinal axis B of the second part 30 in a third or fourth direction, which is offset by a distance D.sub.s2 along the longitudinal axis ZZ of the said connecting bridge 40.

[0064] Depending on the pathological case, the implant 1 can have a connecting bridge 40 positioned, based on its profile, on axis B either: [0065] Tilted at angle with regard to longitudinal axis A and offset in direction D.sub.s1 along axis YY; [0066] Titled at angle with regard to longitudinal axis A and offset in direction D.sub.s2 along axis ZZ; [0067] Titled at angle with regard to longitudinal axis A and offset in the combination of directions D.sub.s1 and/or D.sub.s2.

[0068] According to the invention, distances D.sub.s1 and D.sub.s2 are always above 0 and lower than or equal to 20 millimeters for D.sub.s1 and lower than or equal to 10 millimeters for D.sub.s2.

[0069] This combination of axial offsets of longitudinal axis B of the second part 30 helps prevent the offset of the outer and upper parts between the first bone P2 and the second bone P1 when implant 1 is inserted in their medullary canals.

[0070] According to the embodiment, longitudinal axis A of the first part 20 cuts longitudinal axis B of the second part 30 at a point of intersection I.sub.3 located between the distal end 20a and the proximal end 20b of the said first part 20.

[0071] This point of intersection I.sub.3 is located at a distance L.sub.3 from the proximal end 20b and at a distance L.sub.3 from the distal end 20a of the first part 20.

[0072] The point of intersection I.sub.3 is spaced from the distal end 20a of the first part 20 in the proximal direction so as to be located in an area corresponding to the proximal half of the first part 20. Such embodiments make it possible to optimally offset the distal phalange P2 in the caudal direction from the proximal phalange P1 after insertion.

[0073] Also, the orthonormal axes X, Y Z of the connecting bridge 40 intersect at a point of intersection I.sub.2 which is located at a distance L.sub.2 from the proximal face 30a of the second part 30. Another part of the vertical axis YY of the connecting bridge 40 cuts the longitudinal axis B of the second part 30 at a point of intersection I.sub.1, located at a distance D.sub.s1 from the point of intersection I.sub.2. The longitudinal axis ZZ of the connecting bridge 40 also cuts the longitudinal axis B of the second part 30 at a point of intersection I.sub.4 located at a distance D.sub.s2 from the point of intersection I.sub.2.

[0074] In the variations shown here, the longitudinal axis XX of the connecting bridge 40 of the implant 1 can coincide with the longitudinal axis A of the first part 20 or be titled with regard to the longitudinal axis A of the first part 20.

[0075] Due to its specific structure, the implant 1 according to the invention, once implanted, offsets internally the distal phalange with regard to the proximal phalange. In particular, due to the implant according to the invention, the distal phalange, once fused with the proximal phalange, has a longitudinal axis that is slightly offset downward, in the caudal direction.

[0076] As such, any distal phalange is offset in the caudal direction with regard to an implant from prior art for which axes A and B are not separated by the distance D.sub.s1 and/or D.sub.s2 as defined above.

[0077] After the insertion of the implant according to the invention, the outer parts of the proximal phalange and the distal phalange will be perfectly aligned, and the surgeon does not need to cut the upper part of the bone of the distal phalange to realign the upper parts of the phalanges.

[0078] Indeed, because of the implant according to the invention, the upper part of the bone of the distal phalange does not exceed the upper line of the proximal phalange and this bone does not create a step between the proximal phalange and the distal phalange.

[0079] Also, because of the implant according to the invention, it is possible to fuse two phalanges P1 and P2 into one and block the joint between these two phalanges and treat pathologies such as claw toes, metatarsalgia or even Hallux Valgus.