Orthopedic Implant Tool Coupling Socket

Abstract

An orthopaedic implant tool mating socket for an orthopaedic implant has a stage spaced from an entrance to a blind threaded hole directly below the stage, the stage at least partially defining an engagement surface, a key aperture therethrough, and an extraction tool engagement edge directly below the stage that is not rotationally aligned with the key aperture.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates generally to orthopedic implant tool mating sockets. [Background technology]

[0002] Orthopedic implants generally require features that allow the surgeon to manipulate the implant into place. For example, a femoral prosthesis for hip arthroplasty is inserted into a patient's femur with an impaction tool that couples to the prosthesis.

[0003] Some implants include a recess that positions the tip of an insertion tool, which can then be fitted into and moved around the implant.

[0004] Other implants include a threaded socket onto which an insertion tool is threaded, which can also assist in the removal of the implant. For example, US 20180311050 A1 (Depuy Synthes Products, Inc.), published November 1, 2018, discloses an implant having a neck proximal end that includes an insertion / removal cavity that engages the threaded shaft of an instrument for insertion or removal.

[0005] However, the threads can be damaged by inadvertent cross-threading or by an insertion tool that is not correctly positioned during impaction.

[0006] Damaged threads can prevent or impede disengagement of the insertion tool or, even worse, removal of the implant, as may be required during initial or revision surgery.

[0007] The present invention aims to provide a method for overcoming or substantially ameliorating at least some of the disadvantages of the prior art, or at least to provide an alternative.

[0008] It will be appreciated that where any prior art information is referred to herein, such reference does not constitute an admission that such information forms part of the common general knowledge in the art in Australia or any other country. Summary of the Invention

[0009] Provided herein is an orthopaedic implant tool mating socket for an orthopaedic implant having a stage spaced from an entry to a blind threaded hole beneath the stage, the stage at least partially defining an engagement surface, a key aperture therethrough, and an extraction tool engagement edge beneath the stage that is not rotationally aligned with the key aperture.

[0010] The impact surface is preferably concave and may be hemispherical.

[0011] The threads are protected deep within the socket, which helps prevent cross-threading and / or incorrect tool placement.

[0012] An insertion tool having a rod with a widened portion at its distal end can be used to impact the impaction surface from different angles to manipulate the implant around corners, as may sometimes be required for anterior approach insertion of a hip implant, for example.

[0013] The widened portion and the engagement surface may be hemispherical to equally allow for engagement from a variety of angles, or may be non-hemispherical, such as semi-elliptical, to bias the insertion tool within a range of engagement angles.

[0014] An insertion tool further comprising a distal threaded rod tip extending distally from the widened portion can be threaded onto the threaded portion of the blind threaded hole, where the widened portion abuts the engagement surface to relieve load from the threaded portion.

[0015] Additionally, rotation of the implant may be controlled using a rotation tool that includes a key that fits and sits within a key aperture.

[0016] Additionally, an extraction tool with a key that fits into the keyed aperture can be used to engage the extraction tool engagement edge to quickly and easily remove the implant.

[0017] According to one aspect, an apparatus is provided that includes an orthopaedic implant having an orthopaedic implant tool mating socket, the socket having a stage spaced from an entrance to a blind threaded hole directly below the socket, the stage at least partially defining an engagement surface, a key aperture therethrough, and an extraction tool engagement edge directly below the key aperture that is not rotationally aligned with the key aperture.

[0018] The impact surface may be concave, the impact surface may be hemispherical, or the impact surface may be non-hemispherical, such as semi-elliptical.

[0019] In a cross section perpendicular to the longitudinal axis of the blind hole, the key opening may have a central portion which is larger in cross section than the threaded blind hole. The central portion may be circular in cross section.

[0020] In a cross section perpendicular to the longitudinal axis of the blind hole, the key opening may be elongate in cross section, wherein the key opening may define a pair of slots at opposite ends of a central portion.

[0021] The socket may define a frusto-conical lead-in from beneath the stage into a blind threaded hole.

[0022] The device may further comprise an insertion tool comprising a rod and a widened portion at its distal end, the widened portion fitting the receiving surface of the insertion tool to engage the socket.

[0023] The insertion tool may include a threaded rod tip extending distally from the widened portion that threads into the blind threaded hole until the widened portion abuts the insertion surface.

[0024] The intrusion surface and the wide portion may be hemispherical, or alternatively, the intrusion surface and the wide portion are non-hemispherical, such as semi-elliptical.

[0025] The device may further include an extraction tool having a rod and a key at its distal end, the key shaped to fit into the key slot and engage under the extraction tool engagement edge when rotated out of alignment with the key slot.

[0026] The device may further include a rotary tool having a rod and a key at its distal end, the key shaped to fit into the key socket, and the rotary tool having features that position the key in the key socket when the rotary tool can be forced into the socket.

[0027] The feature may comprise a platform on the key that abuts the mating surface.

[0028] Methods for inserting, extracting, and rotating the socketed implant with various tools are also provided.

[0029] Other aspects of the invention are also disclosed.

[0030] While any other form may fall within the scope of the present invention, preferred embodiments of the present disclosure will now be described by way of example only with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 illustrates a top perspective view of an orthopedic implant with an orthopedic implant tool interface socket according to one embodiment. [Figure 2]1 shows a top plan view of the implant. [Figure 3] 1 shows a cross-sectional side view of an implant. [Figure 4] FIG. 2 shows an enlarged perspective view of the upper part of the socket. [Figure 5] An enlarged cross-sectional view of the socket is shown. [Figure 6] 1 illustrates an insertion tool according to one embodiment. [Figure 7] 10 illustrates a further insertion tool according to an embodiment. [Figure 8] 1 illustrates an extraction tool according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0032] 1-3 show an example of an orthopaedic implant tool coupling socket 100 applied to a hip implant 101. The implant 101 may include a femoral stem 102 and a neck 103 that may have a trunnion 104 that engages the femoral head that fits into the liner of an acetabular cup.

[0033] However, socket 100 may also be applied to other types of orthopedic implants requiring insertion and / or removal.

[0034] Referring to Figures 4 and 5, socket 100 has a stage 105 spaced from the entrance of a blind threaded hole 106 beneath it.

[0035] The spacing from the entrance of the blind hole 106 to the stage 105 may form a gap 107 therebetween. The socket 100 may have a slightly frustoconical lead-in 111 from the gap 107 into the blind threaded hole 106.

[0036] The stage 105 at least partially defines an engagement surface 108 and a key loading aperture 109 therethrough. The stage 105 further defines an extraction tool engaging edge 110 directly below the key loading aperture 109 that is not rotationally aligned with the key loading aperture 109.

[0037] The engagement surface 108 is preferably concave. The engagement surface 108 may be hemispherical. In one embodiment, the engagement surface 108 may be hemispherical (i.e., forming a portion of a sphere of constant radius). In other embodiments, the engagement surface 108 may be non-hemispherical, such as semi-elliptical.

[0038] 2, in a cross section perpendicular to the longitudinal axis of the blind hole 106, the key opening 109 may include a central portion 112 that is larger in cross section than the threaded blind hole 106. The central portion 112 may be circular. The key opening 109 may be elongated and may define a pair of slots 113 at opposite ends of the central portion 112.

[0039] 6 shows an insertion tool 113 comprising a rod 114, a wide portion 115, and a rod tip 116. The wide portion 115 fits against the engagement surface 108. The rod tip 116 includes a threaded portion 117 at its distal end. The rod tip 116 may be inserted into the keyed opening 109, and the rod 114 may be rotated to thread its threaded portion 117 into the threaded portion of the blind threaded hole 106 until the underside of the wide portion 115 contacts the engagement surface 108. The implant 101 may then be moved by inserting the rod 114, where the underside of the wide portion 115 abutting the engagement surface 108 reduces the force applied through the threaded portion 106.

[0040] FIG. 7 shows an insertion tool 118 comprising a rod 114 and a widened portion 115 but lacking a rod tip 116, which may be adapted to engage the surface 108 at various angles.

[0041] 8 shows an extraction tool 119 comprising a rod 114 with an elongated key 115 shaped to fit into the key slot 109 and can be rotated out of alignment with the key slot 109 to engage under the extraction tool engagement edge 110 to remove the implant 101. The extraction tool 119 may also include a proximal slap handle (not shown).

[0042] In some embodiments, a rotation tool (not shown) may be used that has a molded key that fits and sits within the molded key slot 109. The rotation tool may have features that position the key within the molded key slot 109. For example, the rotation tool may have a platform on the key that abuts against the engagement surface 108 to position the key within the molded key slot. Thus, when the rotation tool is twisted, the molded key engages the key slot 109 and rotates the implant.

[0043] The above description for purposes of explanation used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that specific details are not required to practice the present invention. Thus, the above descriptions of specific embodiments of the present invention are provided for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, as obviously many modifications and variations are possible in light of the above teachings. These embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, thereby enabling others skilled in the art to best utilize the invention and various embodiments with various modifications as suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

[0044] As used herein, "approximately" or similar terms should be construed as being within 10% of the stated value unless otherwise indicated.

Claims

1. 1. An apparatus comprising: an orthopedic implant having an orthopedic implant tool mating socket having a stage spaced from an entrance to a blind threaded hole located beneath the socket, the stage at least partially defining an engagement surface, a key aperture extending through the engagement surface, and an extraction tool engagement edge located beneath and out of rotational alignment with the key aperture.

2. The device of claim 1 , wherein the engagement surface is concave.

3. The device of claim 2 , wherein the impact surface is hemispherical.

4. The device of claim 2 , wherein the impact surface is non-hemispherical.

5. The device of claim 4 , wherein the engagement surface is semi-elliptical.

6. 2. The device of claim 1, wherein in a cross section perpendicular to a longitudinal axis of the blind hole, the key opening includes a central portion, the cross section of the central portion being larger than the cross section of the threaded blind hole.

7. The device of claim 6 , wherein the central portion has a circular cross section.

8. 7. The device of claim 6, wherein the cross section of the key opening is elongated in a cross section perpendicular to the longitudinal axis of the blind hole.

9. 9. The device of claim 8, wherein the key opening defines a pair of slots at opposite ends of the central portion.

10. The apparatus of claim 1 , wherein the socket defines a frusto-conical lead-in from beneath the stage into the blind threaded hole.

11. The device described in claim 1, further comprising an insertion tool having a rod and a wide portion at its distal end, the wide portion engaging the socket so that the insertion tool conforms to its insertion surface.

12. 12. The apparatus of claim 11, wherein the insertion tool further comprises a threaded rod tip extending distally from the widened portion, the threaded rod tip threadably engaging within the blind threaded hole.

13. 13. The device of claim 12, wherein the threaded rod tip threads into the blind threaded hole until the widened portion abuts the mating surface.

14. The device of claim 11 , wherein the engagement surface and the widened portion are hemispherical.

15. The device of claim 11 , wherein the engagement surface and the widened portion are non-hemispherical.

16. 16. The device of claim 15, wherein the engagement surface and the wide portion are semi-elliptical.

17. The device of claim 1, further comprising an extraction tool having a rod and a key at its distal end, the key being shaped to fit into the key opening and to engage under the extraction tool engagement edge when rotated out of alignment with the key opening.

18. The device described in claim 1, further comprising a rotary tool having a rod and a key at its distal end, the key being shaped to fit into the key socket, and the rotary tool having features that position the key within the key socket when the rotary tool is pressed into the socket.

19. 20. The device of claim 18, wherein the feature comprises a platform on the key, the platform abutting the engagement surface.

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