Implant removal tool

Abstract

An implant removal tool (1) used to remove a femoral implant (17) from a femur (18) by providing a generally U-shaped body (2). The generally U-shaped body has a generally rectangular opening (9) located thereon that allows the generally U-shaped body to be placed over the neck (21) of the femoral implant so that a sharp front edge (5) of the generally U-shaped body directly contacts the inner surface of the stem of the femoral implant. The U-shaped body may have front side edges (26, 27) that extend beyond the front edge (5) and allow the front side edges to cut the anterior and posterior surfaces of the implant.

Description

Technical Field

[0001] (Field of the Invention) The present invention relates to hip implant replacement surgery, and more particularly to an implant removal tool designed to fit around the angled neck of a femoral implant and cut around the stem of the femoral implant with minimal bone loss.

Background Art

[0002] (Background of the Invention) Total joint arthroplasty (especially total hip arthroplasty) has an increasing implementation rate in the United States and other developed countries. Unfortunately, many of these joint replacements fail over time, requiring replacement surgery, and the original implant is removed from the bone and replaced with a new implant. Furthermore, due to the rapid increase in the elderly population, the number of patients requiring replacement of failed joint arthroplasty is increasing.

[0003] The goal of such replacement surgery is to remove the implant with minimal damage to the bone tissue. In most hip replacements, the implant is fixed to the bone with the aid of an adhesive and through the final regrowth of bone tissue around the implant and into the porous surface of the metal implant. In replacement surgery, the removal of the existing implant is often a difficult task to accomplish without damaging the bone surrounding the implant.

[0004] This is especially true for femoral implants where the stem of the femoral implant is inserted into the upper end of the femur. An angled neck extends upward from the stem, mimicking the natural neck of the femur and providing a mounting point for the head to be attached.

[0005] Ideally, the cutting tool is firmly pressed against the surface of the neck to ensure that as little bone as possible is removed. However, the angled neck makes it nearly impossible to angle the cutting tool to cut around the inner surface of the stem without removing an excessive amount of bone. Since the new implant requires a minimal amount of bone support to succeed in this way, the removal of excessive bone can be very detrimental to the patient. In addition, this removal of excessive bone leads to increased surgical time, increased recovery time, failed replacement implants, and in some cases, the patient being wheelchair-bound for the rest of their life.

[0006] Accordingly, there is a need for an implant removal tool designed to fit around the angled neck of a femoral implant and cut around the stem of the femoral implant with minimal bone loss. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM

[0007] A primary object of the present invention is to provide an implant removal tool that fits around the angled neck of a femoral implant and cuts around the stem of the femoral implant with minimal bone loss.

[0008] The present invention provides an implant removal tool used to remove a femoral implant by providing a substantially U-shaped body having a substantially rectangular-shaped opening located thereon, the substantially rectangular-shaped opening enabling the substantially U-shaped body to be installed across the neck of the femoral implant with the neck of the femoral implant extending through the substantially rectangular-shaped opening, and thus enabling the sharp front edge of the substantially U-shaped body to directly contact the inner surface of the stem of the femoral implant. When positioned, the U-shaped body can be pushed into the bone and cut the stem away from the bone, while the sharp front edge maintains substantial contact with the stem of the implant, thereby preventing unnecessary loss of bone.

[0009] The U-shaped body may have a front side edge that extends beyond the front edge and enables the front side edge to cut the front and rear surfaces of the implant.

[0010] The above and other objects, features, and advantages of the present invention should become more readily apparent to those skilled in the art upon a perusal of the following detailed description in conjunction with the drawings in which illustrative embodiments of the invention are shown and described. This specification also provides, for example, the following. (Item 1) An implant removal tool, A substantially U-shaped body having a curved inner surface, a curved outer surface, a front edge, a right edge, a left edge, and a back surface, A substantially rectangular opening located on the substantially U-shaped body between the right edge and the left edge, The substantially rectangular opening having a front edge, a back edge, a right edge, and a left edge An implant removal tool comprising. (Item 2) The implant removal tool according to item 1, wherein the front edge of the substantially U-shaped body is sharp. (Item 3) The implant removal tool according to item 1, wherein the front edge of the substantially rectangular opening is curved. (Item 4) The implant removal tool according to item 1, further comprising attachment means located on the back surface of the substantially U-shaped body. (Item 5) The front right edge forms a triangular point, The implant removal tool according to item 1, wherein the front left edge forms a triangular point. (Item 6) The implant removal tool according to item 5, wherein the front edge of the substantially U-shaped body is sharp. (Item 7) The front right edge is sharp, The implant removal tool according to item 5, wherein the front left edge is sharp. (Item 8) An implant removal tool, A substantially U-shaped body having a curved inner surface, a curved outer surface, a front edge, a right edge, a left edge, and a back surface, A substantially rectangular opening located on the substantially U-shaped body between the right edge and the left edge Comprising, The substantially rectangular opening has a front edge, a back edge, a right edge, and a left edge, The implant removal tool, wherein the front edge of the substantially U-shaped body is sharp. (Item 9) The implant removal tool according to item 7, wherein the front edge of the substantially rectangular opening is curved. (Item 10) The implant removal tool according to item 7, further comprising attachment means located on the back surface of the substantially U-shaped body. (Item 11) The implant removal tool according to item 9, wherein the attachment means is a threaded member. (Item 12) The implant removal tool according to item 7, further comprising a handle extending from the back surface of the substantially U-shaped body. (Item 13) The implant removal tool according to item 7, further comprising a handle extending from the back surface of the substantially U-shaped body. (Item 14) An implant removal tool, A substantially U-shaped body having a curved inner surface, a curved outer surface, a front edge, a right edge, a left edge, and a back surface, a substantially rectangular-shaped opening located on the substantially U-shaped body between the right edge and the left edge and comprising the substantially rectangular-shaped opening has a front edge, a rear edge, a right edge, and a left edge the front edge of the substantially U-shaped body is sharp the front edge of the substantially rectangular-shaped opening is curved, an implant removal tool (Item 15) The implant removal tool according to item 12, further comprising attachment means located on the rear surface of the substantially U-shaped body (Item 16) The implant removal tool according to item 13, wherein the attachment means is a threaded member (Item 17) The implant removal tool according to item 12, further comprising a handle extending from the rear surface of the substantially U-shaped body (Item 18) An implant removal tool comprising a substantially U-shaped body having a curved inner surface, a curved outer surface, a front edge, a right edge, a left edge, a front right edge, a front left edge, and a rear surface the front right edge of the U-shaped body and the front left edge of the U-shaped body extend beyond the front edge, an implant removal tool (Item 19) the front right edge forms a triangular point the front left edge forms a triangular point, the implant removal tool according to item 17 (Item 20) the front edge of the substantially U-shaped body is sharp, the implant removal tool according to item 17 (Item 21) the front right edge is sharp the front left edge is sharp, the implant removal tool according to item 19

Brief Description of the Drawings

[0011] In the following detailed description, the accompanying drawings are referenced.

[0012]

Figure 1

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Mode for Carrying Out the Invention

[0013] (Description of Preferred Embodiment) For the purpose of describing the preferred embodiment, the technical terms used with reference to the numbered accessories in the drawings are as follows. 1. Generally, the implant removal tool 2. U-shaped body 3. Curved inner surface of the U-shaped body 4. Curved outer surface of the U-shaped body 5. Front edge of the U-shaped body 6. Right side edge of the U-shaped body 7. Left side edge of the U-shaped body 8. Rear surface of the U-shaped body 9. Rectangular opening 10. Front edge of the rectangular opening 11. Rear edge of the rectangular opening 12. Right side edge of the rectangular opening 13. Left side edge of the rectangular opening 14. Mounting means 15. Threaded member 16. Handle 17. Femoral implant 18. Femur 19. Stem 20. Upper end of the femur 21. Neck 22. Upper part of the stem 23. Introducer 24. Curved body of the introducer 25. Sharp front edge of the introducer 26. Front right edge of the U-shaped body 27. Front left edge of the U-shaped body 28. Triangular point

[0014] Referring to FIGS. 1-6, the implant removal tool 1 of the present invention is illustrated. The implant removal tool 1 includes a generally U-shaped body 2 having a curved inner surface 3, a curved outer surface 4, a front edge 5, a right edge 6, a left edge 7, and a back surface 8. The front edge 5 of the generally U-shaped body 2 is preferably sharp. The front right edge 26 of the U-shaped body 2 and the front left edge 17 of the U-shaped body 2 are also preferably sharp.

[0015] A generally rectangular-shaped opening 9 is located on the generally U-shaped body 2 between its right edge 6 and left edge 7. The generally rectangular-shaped opening 9 includes a front edge 10, a back edge 11, a right edge 12, and a left edge 13. The front edge 10 of the generally rectangular-shaped opening 9 is preferably curved to enable the front edge 10 to conform to the curved shape of the femoral implant.

[0016] Mounting means 14, such as a threaded member 15, extends from the back surface 8 of the generally U-shaped body 2 and enables a handle 16 to be attached to the generally U-shaped body 2 as shown in FIG. 8. Alternatively, the handle may be integrated with the generally U-shaped body 2.

[0017] Referring to FIG. 7, a partial cutaway view of a conventional femoral implant 17 implanted within the femur 18 is illustrated. The femoral implant 17 includes a stem 19 that is inserted into the upper end 20 of the femur 18. The angled neck 21 extends upwardly from the stem 19 at an angle and / or offset so as to mimic the natural neck of the femur 18, which has been removed from the femur 18. The upper portion 22 of the stem 19 is textured and / or porous to enable the femur 18 and / or an adhesive to grip the stem 19 and secure it within the femur 18.

[0018] Referring to FIG. 8, a partial cutaway view of a conventional femoral implant 17 implanted within the femur 18 and an implant removal tool 1 of the present invention engaging the femoral implant 17 and the femur 18 is shown.

[0019] The generally rectangular-shaped opening 9 enables the generally U-shaped body 2 to be positioned over the neck 21 of the femoral implant 17 with the neck 21 of the femoral implant 17 extending through the generally rectangular-shaped opening 9. Accordingly, the sharp front edge 5 of the generally U-shaped body 2 directly contacts the inner edge 23 of the stem 19 of the femoral implant 17. Once positioned, the U-shaped body 2 can be pushed into the femur 18 to cut the stem 19 away from the femur 18 while the sharp front edge 5 maintains substantial contact with the stem 19 of the femoral implant 17, thereby preventing unnecessary loss of the femur 18.

[0020] As shown herein, the upper portion 22 of the stem 19 and the texture disposed only thereon extend along the stem 19 over a predetermined distance before the stem 19 extends thereover. In most cases, the upper portion 22 of the stem 19 is the only portion of the femoral implant 17 that is required to be cut away from the femur 18. Accordingly, the lengths of the right edge 12 and the left edge 13 of the generally rectangular-shaped opening 9 are preferably equal to the height of the upper portion 22 of the stem 19. This prevents the back edge 11 of the generally rectangular-shaped opening 9 from contacting the angled neck 21 and the sharp front edge 5 from extending beyond the upper portion 22 of the stem 19.

[0021] Referring to FIGS. 9 and 10, respectively, a top perspective view and a top view of the implant removal tool 1 of the present invention are shown, with the front side edges extending beyond the front edge to enable the tool to cut the front and back surfaces of the implant away from the bone. The implant removal tool 1 includes a generally U-shaped body 2 having a curved inner surface 3, a curved outer surface 4, a front edge 5, a right edge 6, a left edge 7, and a back surface 8.

[0022] The front edge 5 of the substantially U-shaped body 2 is preferably sharp. The front right edge 26 of the U-shaped body 2 and the front left edge 17 of the U-shaped body 2 are also preferably sharp. The front right edge 26 of the U-shaped body 2 and the front left edge 17 of the U-shaped body 2 extend beyond the front edge 5 and each form a triangular-shaped point 28.

[0023] Mounting means 14 such as the threaded member 15 extends from the back surface 8 of the substantially U-shaped body 2 and enables the handle 16 to be attached to the substantially U-shaped body 2 as shown in FIG. 11. Alternatively, the handle may be integrated with the substantially U-shaped body 2.

[0024] Referring to FIG. 11, a partial cutaway view of a conventional femoral implant 17 implanted in the femur 18 and the implant removal tool 1 of the present invention is shown, with the front side edges 26, 27 extending beyond the front edge 5 and enabling the tool to cut from the femur 18 engaging the front and back surfaces of the implant 17 to the femoral implant 17.

[0025] The front edge 5 of the substantially U-shaped body 2 is preferably sharp. The front right edge 26 of the U-shaped body 2 and the front left edge 17 of the U-shaped body 2 are also preferably sharp. The front right edge 26 of the U-shaped body 2 and the front left edge 17 of the U-shaped body 2 extend beyond the front edge 5 and each form a triangular-shaped point 28.

[0026] Referring to FIG. 12, a perspective view of the introducer 23 of the present invention is shown. The introducer 23 may be used to create an initial opening between the femur and the femoral implant. After the initial opening is created, the sharp front edge 5 of the implant removal tool 1 may then be inserted into the initial opening. The introducer 23 preferably has an elongated curved body 24 and a sharp front edge 25, and the elongated curved body 24 enables the introducer 23 to reach around the angled neck 21 and, if necessary, create an initial opening.

[0027] Although preferred embodiments of the present invention are illustrated, it should be understood that the present invention is not limited to the specific forms or arrangements of the components described and illustrated herein. Various changes may be made without departing from the scope of the present invention, and it will be apparent to those skilled in the art that the present invention should not be regarded as limited to what is illustrated and described in the specification and drawings.

Claims

1. An implant removal tool, comprising a generally U-shaped body having a curved inner surface, a curved outer surface, a front edge, a right side edge, a left side edge, and a rear surface, and an elongated opening located on the generally U-shaped body between the right side edge and the left side edge ; the elongated opening has a front edge, a rear edge, a right side edge, and a left side edge, the curved inner surface defines an internal space, and the elongated opening has a width substantially equal to the width of the internal space, the implant removal tool.

2. The implant removal tool according to claim 1, wherein the front edge of the generally U-shaped body is sharp.

3. The implant removal tool according to claim 1, wherein the front edge of the elongated opening is curved.

4. The implant removal tool according to claim 1, further comprising mounting means located on the rear surface of the generally U-shaped body.

5. The generally U-shaped body further has a front right side edge and a front left side edge, and the front right side edge and the front left side edge extend beyond the front edge of the generally U-shaped body, the implant removal tool according to claim 1.

6. The implant removal tool according to claim 5, wherein the front edge of the generally U-shaped body is sharp.

7. The front right side edge is sharp, and the front left side edge is sharp, the implant removal tool according to claim 5.

8. An implant removal tool, comprising a generally U-shaped body having a curved inner surface, a curved outer surface, a front edge, a right side edge, a left side edge, and a rear surface, and an elongated opening located on the generally U-shaped body between the right side edge and the left side edge ; the elongated opening has a front edge, a rear edge, a right side edge, and a left side edge, the front edge of the generally U-shaped body is sharp, the curved inner surface defines an internal space, and the elongated opening has a width substantially equal to the width of the internal space, the implant removal tool.

9. The implant removal tool according to claim 7, wherein the front edge of the elongated opening is curved.

10. The implant removal tool according to claim 7, further comprising mounting means located on the rear surface of the generally U-shaped body.

11. The implant removal tool according to claim 10, wherein the mounting means is a threaded member.

12. The implant removal tool according to claim 7, further comprising a handle extending from the rear surface of the generally U-shaped body.

13. An implant removal tool, A substantially U-shaped body having a curved inner surface, a curved outer surface, a front edge, a right edge, a left edge, and a rear surface, An elongated opening located on the substantially U-shaped body between the right edge and the left edge Comprising, The elongated opening has a front edge, a rear edge, a right edge, and a left edge, The front edge of the substantially U-shaped body is sharp, The front edge of the elongated opening is curved, The curved inner surface defines an internal space, The elongated opening has a width substantially equal to the width of the internal space, an implant removal tool.

14. The implant removal tool according to claim 12, further comprising attachment means located on the rear surface of the substantially U-shaped body.

15. The implant removal tool according to claim 14, wherein the attachment means is a threaded member.

16. The implant removal tool according to claim 12, further comprising a handle extending from the rear surface of the substantially U-shaped body.

17. An implant removal tool, A substantially U-shaped body having a curved inner surface, a curved outer surface, a front edge, a right edge, a left edge, a front right edge, a front left edge, and a rear surface, An elongated opening located on the substantially U-shaped body between the right edge and the left edge Comprising, The front right edge of the substantially U-shaped body and the front left edge of the substantially U-shaped body extend beyond the front edge, The curved inner surface defines an internal space, The elongated opening has a width substantially equal to the width of the internal space, an implant removal tool.

18. The substantially U-shaped body further has a front right edge and a front left edge, The implant removal tool according to claim 16, wherein the front right edge and the front left edge extend beyond the front edge of the substantially U-shaped body.

19. The implant removal tool according to claim 16, wherein the front edge of the substantially U-shaped body is sharp.

20. The front right edge is sharp, The implant removal tool according to claim 18, wherein the front left edge is sharp.

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