Interphalangeal arthrodesis implant

Abstract

This interphalangeal arthrodesis implant comprises a proximal anchor portion intended to be engaged and anchored in the medullary canal of a first phalanx sectioned along a first osteotomy plane, the proximal anchor portion including a plurality of proximal anchor branches each provided with at least one bone anchor element; and a distal anchor portion, connected to the proximal anchor portion, intended to be engaged and anchored in the medullary canal of a second phalanx sectioned along a second osteotomy plane, the distal anchor portion including a plurality of distal anchor branches each provided with at least one bone anchor element. The distal anchor portion comprises a stop portion including a stop surface intended to bear against a sectioned surface of the first phalanx extending along the first osteotomy plane.

Claims

1. An interphalangeal arthrodesis implant intended to allow a bone fusion between a first and a second phalanxes of an interphalangeal joint, the interphalangeal arthrodesis implant being made in one piece and comprising: a proximal anchor portion intended to be engaged and anchored in a medullary canal of the first phalanx previously sectioned along a first osteotomy plane (P1), the proximal anchor portion including a plurality of proximal anchor branches each provided with at least one bone anchor element and each proximal anchor branch having a generally elongated shape, the proximal anchor branches being separate and distinct from each other, the proximal anchor portion including a plurality of proximal longitudinal slots angularly offset and defining the plurality of proximal anchor branches, the plurality of proximal anchor branches defining a hollow proximal channel in which emerges each of the proximal longitudinal slots, a distal anchor portion, connected to the proximal anchor portion, intended to be engaged and anchored in a medullary canal of the second phalanx previously sectioned along a second osteotomy plane (P2), the distal anchor portion including a plurality of distal anchor branches each provided with at least one bone anchor element and each distal anchor branch having a generally elongated shape, the distal anchor branches being separate and distinct from each other, the distal anchor portion including a plurality of distal longitudinal slots angularly offset and defining the plurality of distal anchor branches, the plurality of distal anchor branches defining a hollow distal channel in which emerges each of the distal longitudinal slots, the distal anchor portion comprising a stop portion including a stop surface intended to bear against a sectioned surface of the first phalanx extending along the first osteotomy plane (P1), wherein each proximal anchor branch includes a first end and a second end opposite the respective first end, the first end of each proximal anchor branch being closer to the distal anchor portion than the respective second end and the first end of each proximal anchor branch being spaced from a first axis of extension (A) of the proximal anchor portion by a first proximal distance and the second end of each proximal anchor branch being spaced from the first axis of extension (A) of the proximal anchor portion by a second proximal distance, the first proximal distance being greater than the second proximal distance, and each distal anchor branch includes a first end and a second end opposite to the respective first end, the first end of each distal anchor branch being closer to the proximal anchor portion than the respective second end and the first end of each distal anchor branch being spaced from a second axis of extension (B) of the distal anchor portion by a first distal distance and the second end of each distal anchor branch being spaced from the second axis of extension (B) of the distal anchor portion by a second distal distance, the first distal distance being greater than the second distal distance, wherein the proximal anchor portion includes a proximal end portion connecting the second ends of the proximal anchor branches, and the distal anchor portion includes a distal end portion connecting the second ends of the distal anchor branches, the proximal anchor branches converging inwardly towards each other in the direction of the proximal end portion as they extend from their respective first end towards their respective second end and the distal anchor branches converging inwardly towards each other in the direction of the distal end portion as they extend from their respective first end towards their respective second end.

2. The interphalangeal arthrodesis implant according to claim 1, wherein the stop surface is substantially planar.

3. The interphalangeal arthrodesis implant according to claim 1, wherein the stop surface is annular.

4. The interphalangeal arthrodesis implant according to claim 1, wherein the proximal anchor portion extends generally along the first axis of extension (A), and the distal anchor portion extends generally along the second axis of extension (B).

5. The interphalangeal arthrodesis implant according to claim 4, wherein the first and second axes of extension (A, B) are inclined relative to one another.

6. The interphalangeal arthrodesis implant according to claim 4, wherein the proximal anchor branches are distributed around the first axis of extension (A), and the distal anchor branches are distributed around the second axis of extension (B).

7. The interphalangeal arthrodesis implant according to claim 1, wherein the proximal anchor portion further includes a connecting portion connecting the stop portion and the proximal anchor branches.

8. The interphalangeal arthrodesis implant according to claim 7, wherein the connecting portion has a substantially smooth outer surface.

9. The interphalangeal arthrodesis implant according to claim 7, wherein the connecting portion has a substantially circular cross section.

10. The interphalangeal arthrodesis implant according to claim 7, wherein the first ends of the proximal anchor branches are connected to the connecting portion, and the first ends of the distal anchor branches are connected to the stop portion.

11. The interphalangeal arthrodesis implant according to claim 1, wherein the proximal and distal end portions each have a generally bullet shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In any case, the invention will be well understood using the following description with reference to the appended schematic drawing showing, by way of non-restrictive example, an embodiment of this interphalangeal arthrodesis implant.

(2) FIG. 1 is a perspective view of an interphalangeal arthrodesis implant according to the present invention.

(3) FIGS. 2 and 3 are respectively side and top views of the interphalangeal arthrodesis implant of FIG. 1.

(4) FIG. 4 is a side view of a second toe of a foot, schematizing first and second osteotomy planes respectively of the first and second phalanxes of the proximal interphalangeal joint of the second toe.

(5) FIGS. 5 and 6 are views showing steps of machining the medullary canals of the first and second phalanxes of FIG. 4.

(6) FIGS. 7 to 9 are views showing different steps of fastening the interphalangeal arthrodesis implant of FIG. 1 in the first and second phalanxes of FIG. 4.

(7) FIG. 10 is a perspective view of a range of interphalangeal arthrodesis implants according to the present invention.

BRIEF DESCRIPTION

(8) FIGS. 1 to 3 show an interphalangeal arthrodesis implant 2 intended to allow a bone fusion between a first and a second phalanxes 3, 4 of a proximal interphalangeal joint 5 of a foot. The interphalangeal arthrodesis implant 2 is advantageously formed in one piece, and can be made, for example, of plastic material, such as PEEK.

(9) The interphalangeal arthrodesis implant 2 comprises a proximal anchor portion 6 intended to be engaged and anchored in the medullary canal 7 of the first phalanx 3 previously sectioned along a first osteotomy plane P1, and a distal anchor portion 8 intended to be engaged and anchored in the medullary canal 9 of the second phalanx 4 previously sectioned along a second osteotomy plane P2.

(10) The proximal anchor portion 6 has a generally elongated shape, and extends generally along a first axis of extension A. The proximal anchor portion 6 includes a connecting portion 11 connected to the distal anchor portion 8 and extending along the first axis of extension A. According to the embodiment shown in Figures, the connecting portion 11 has a smooth outer surface and a circular cross section.

(11) The proximal anchor portion 6 further includes a plurality of proximal anchor branches 12, for example four, regularly distributed around the first axis of extension A. Each proximal anchor branch 12 has a generally elongated shape and includes a first end 12a connected to the connecting portion 11 and a second end 12b opposite the respective first end 12a. Thus, each proximal anchor branch 12 extends from the connecting portion 11.

(12) Each proximal anchor branch 12 is advantageously provided with a plurality of bone anchor notches 13 disposed along the respective proximal anchor branch 12.

(13) The proximal anchor portion 6 also includes a proximal end portion 14 connecting the second ends 12b of the proximal anchor branches 12. According to the embodiment shown in Figures, the proximal end portion 14 has a generally bullet shape and includes a planar proximal end face 15 and extending perpendicularly to the first axis of extension A.

(14) The distal anchor portion 8 has generally an elongated shape and extends generally along a second axis of extension B inclined relative to the first axis of extension A by an angle comprised, for example, between 3 and 15.

(15) The distal anchor portion 8 includes a stop portion 16 including a stop surface 17 intended to bear against a sectioned surface of the first phalanx 3. It should be noted that the connecting portion 11 is configured to connect the stop portion 16 and the proximal anchor branches 12.

(16) According to the embodiment shown in the figures, the stop surface 17 is formed by a shoulder configured so that the stop portion 16 has an external diameter greater than the external diameter of the connecting portion 11. Advantageously, the stop surface 17 is annular and extends coaxially with the second axis of extension. According to the embodiment shown in the figures, the stop surface 17 is planar and extends in an inclined manner relative to the first axis of extension A.

(17) The distal anchor portion 8 further includes a plurality of distal anchor branches 18, for example four, regularly distributed around the second axis of extension B. Each distal anchor branch 18 has a generally elongated shape and includes a first end 18a connected to the stop portion 16 and a second end 18b opposite the respective first end 18a. Thus, each distal anchor branch 18 extends from the stop portion 16.

(18) Each distal anchor branch 18 is advantageously provided with a plurality of bone anchor notches 19 disposed along the respective distal anchor branch 18.

(19) The distal anchor portion 8 also includes a distal end portion 21 connecting the second ends 18b of the distal anchor branches 18. According to the embodiment shown in Figures, the distal end portion 21 has a generally bullet shape and includes a planar distal end face 22 and extending perpendicularly to the second axis of extension B.

(20) According to the embodiment shown in Figures, the proximal anchor branches 12 converge substantially in the direction of the distal end portion 14 and the distal anchor branches 18 converge substantially in the direction of the distal end portion 21.

(21) A method for correcting a deformation of the second toe of a patient suffering from a hallux valgus using an interphalangeal arthrodesis implant 2 according to the present invention will now be described, by referring more particularly to FIGS. 4 to 9.

(22) Such a correction method comprises the steps consisting in: performing an osteotomy of the first and second phalanxes 3, 4 of the second toe on either side of the proximal interphalangeal joint and along a first and second osteotomy planes P1, P2 respectively extending substantially perpendicularly to the first and second phalanxes 3, 4 (see FIG. 4), machining, using a conformation tool 23, the medullary canal 7 of the first phalanx 3 and the medullary canal 9 of the second phalanx 4 such that they have dimensions corresponding substantially to the outer dimensions of the proximal and distal anchor portions 6, 8 of the interphalangeal arthrodesis implant 2 (see FIGS. 5 and 6), inserting and anchoring, using a gripping tool 24, the proximal anchor portion 6 in the medullary canal 7 of the first phalanx 3 previously sectioned along the first osteotomy plane P1, so that the stop surface 17 bears against the sectioned surface 25 of the first phalanx 3 extending along the first osteotomy plane P1 (see FIGS. 7 and 8), inserting and anchoring the distal anchor portion 8 in the medullary canal 9 of the second phalanx 4 previously sectioned along the second osteotomy plane P2, so that the sectioned surfaces 25, 26 of the first and second phalanxes 3, 4 bear against one another.

(23) As shown in FIG. 10, the interphalangeal arthrodesis implant 2 can be declined, for example, in two angulations, that is to say in two values of the angle of inclination between the first and second axes of extension A, B, and in two sizes. Such a declination of the interphalangeal arthrodesis implant 2 allows forming a range of implants comprising four different implants. However, the interphalangeal arthrodesis implant 2 could be declined in more than two angulations, for example in three or four different angulations, and in more than two sizes, for example in three or four different sizes, in order to respond to the different anatomies which can be encountered.

(24) It goes without saying that the invention is not limited to the sole embodiment of this interphalangeal arthrodesis implant, described above by way of example, but it embraces, on the contrary, all the variants.