CABLE PLUG
Disclosed herein are cable plugs for securing surgical cable to a bone plate. The cable plugs each have a cable retaining member and a fastening member. The cable retaining members each have a receiving portion adapted to receive a portion of the surgical cable therein. The cable retaining members are first coupled to the fastening members prior to securing the cable plug to the bone plate. The cable retaining member may rotate with respect to the fastening member about 270° along a longitudinal axis of the cable plug when the cable retaining member is coupled to the fastening member. When securing the surgical cable to the bone plate, the cable retaining member is rotated about the longitudinal axis of the cable plug until an axis of the receiving portion is parallel to an axis of the surgical cable. The surgical cable is then placed within the receiving portion, tightened, and crimped to secure the bone plate to the bone.
The present application is a continuation of U.S. patent application Ser. No. 13/649,249 filed Oct. 11, 2012, the disclosure of which is hereby incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates to systems for coupling surgical cables to bone plates when reducing bone fractures or repairing fractured bones. More particularly, the invention relates to systems that utilize a cable retaining member, affixed to a bone plate, to receive and retain a surgical cable. In which, the surgical cable may be oriented with respect to the bone at a plurality of angles relative to the longitudinal axis of the bone.
BACKGROUND OF THE INVENTIONSurgical cables are used in many surgical procedures. They are generally used to encircle the bone alone, or the bone and a bone plate, to facilitate fixation of one or more bone fragments. Some bone fixation systems that use surgical cable also use a bone plate having a length sufficient to span the bone fragments, fixation screws to couple the bone plate to the bone, adapters to couple the cable to the bone plate, and crimp devices for securing ends of the cable. In these systems, the surgical cable is generally coupled to the bone or the bone plate at 90° from the longitudinal axis of the bone.
Because the surgical cable is wrapped around the bone and bone plate, as forces act on the cable, the cable may tend to move from its coupled position with respect to the bone plate. As such forces act on the cable, a longitudinal axis of the cable will generally tend to be angled at less than 90° from the longitudinal axis of the bone. This may result in shear stresses and strains in the surgical cable that cause the bone plate to shift relative to the bone.
Some fixation screws function to both couple the bone plate to bone and as a means for coupling the cable at a certain position along a length of the bone plate. If the fixation screws are used to couple the cable to the bone plate, the cable is generally received in a slot or bore in a head portion of the fixation screws. Such fixation screws also act as an adapter. The head portion of the fixation screws are generally integrally coupled to a shaft of the fixation screws but may be a separate component that is coupled to the shaft of the fixation screws.
The adapters and fixation screws explained above generally function to prevent migration of surgical cable along a longitudinal axis of a bone plate. However, these systems do not provide a means of orienting the surgical cable at an angle less than 90° from the longitudinal axis of the bone. Therefore, they cannot sufficiently eliminate the stresses and strains in the surgical cable which may cause shifting of the bone plate.
BRIEF SUMMARY OF THE INVENTIONA first aspect in accordance with one embodiment of the present invention is a cable plug. The cable plug includes a cable retaining member having a head portion, a shaft portion and a stopper member, the head portion having a base surface and at least two receiving members projecting upwardly from the base surface for receiving a surgical cable. The cable plug further includes a fastening member having a top surface, a bottom surface, and an outer circumference, the fastening member having an opening to receive the shaft of the cable retaining member and a boss in the opening. When the cable retaining member is coupled to the fastening member, the cable retaining member is rotatable with respect to the fastening member until the stopper member contacts the boss of the fastening member. When surgical cable is received in the at least two receiving members of the cable retaining member, and the cable plug is assembled to a bone plate, the cable plug provides freedom to rotate the surgical cable without adding torque stresses to the plate and the bone that the plate contacts.
In accordance with one embodiment of this first aspect of the present invention, the at least two receiving members form a channel adapted to receive a surgical cable therein. The surgical cable preferably includes a diameter and the at least two receiving members have oppositely facing surfaces separated by a horizontal distance equal to or greater than the diameter of the surgical cable throughout a vertical length of the at least two receiving members.
In accordance with another embodiment of this first aspect of the present invention, the surgical cable includes a diameter and the at least two receiving members have oppositely facing surfaces separated by a horizontal distance equal to or greater than the diameter of the surgical cable at the base surface of the head portion and less than the diameter of the surgical cable adjacent a top portion of the cable plug.
In accordance with yet another embodiment of this first aspect of the present invention, the cable retaining member includes two sets of at least two receiving members, the two sets of at least two receiving members forming at least two channels adapted to receive surgical cable therein.
In accordance with still yet another embodiment of this first aspect of the present invention, the cable retaining member includes one set of at least two receiving members and a bore hole, the one set of at least two receiving members forming a channel, the bore hole extending through the at least two receiving members, wherein the channel and bore hole are each adapted to receive surgical cable therein. Preferably, the diameter of the channel and bore hole are different such that each are configured to receive a surgical cable with a different diameter.
In accordance with still yet another embodiment of this first aspect of the present invention, the cable retaining member includes an engagement recess that is centrally located between the at least two receiving members, the engagement recess adapted to receive an insertion tool.
In accordance with yet still another embodiment of this first aspect of the present invention, the base surface of the cable retaining member lies adjacent the top surface of the fastening member when the cable retaining member is coupled to the fastening member.
In accordance with yet still another embodiment of this first aspect of the present invention, the opening in the fastening member is irregularly shaped and includes a top portion adapted to receive the stopper member and a bottom portion adapted to receive the shaft of the cable retaining member when the cable retaining member is coupled to the fastening member. The top portion of the opening extends at least 90° about a longitudinal axis of the cable plug. Preferably, the top portion of the opening extends 270° about a longitudinal axis of the cable plug.
In accordance with yet still another embodiment of this first aspect of the present invention, the opening in the fastening member is irregularly shaped and includes a top portion shaped as a keyhole and adapted to receive the shaft and stopper member of the cable retaining member therethrough and a bottom portion adapted to house the stopper member when the cable retaining member is being rotated with respect to the fastening member.
A second aspect in accordance with one embodiment of the present invention is a cable plug. The cable plug includes a cable retaining member having a head portion and a shaft portion, the head portion having a base surface and at least two receiving members projecting upwardly from the base surface, the shaft portion extending downwardly from the base surface. The cable plug further includes a fastening member having a top surface, a bottom surface, and an outer circumference, the fastening member having an opening in the top surface adapted to receive the shaft of the cable retaining member. The cable plug further includes a stopper member engaged to the cable retaining member, wherein when the cable retaining member is coupled to the fastening member, the cable retaining member may be rotated with respect to the fastening member in a first rotational direction about a longitudinal axis of the cable plug until the stopper member contacts a first stop surface of the fastening member.
According to one embodiment of this second aspect, when the cable retaining member is operatively coupled to the fastening member, the cable retaining member may be rotated with respect to the fastening member in a second rotational direction opposite the first rotational direction about a longitudinal axis of the cable plug until the stopper contacts a second stop surface of the fastening member.
A third aspect in accordance with one embodiment of the present invention is a method for securing a bone plate to a bone of a patient. The method includes inserting a cable plug into a hole in the bone plate, contacting the bone with the bone plate, and wrapping surgical cable having a longitudinal axis around the bone and the bone plate. The method further includes rotating a cable retaining member of the cable plug about a longitudinal axis of the cable plug until a longitudinal axis of a channel formed by at least two receiving members of the cable retaining member are parallel to the longitudinal axis of the surgical cable, placing the surgical cable in the channel of the cable retaining member, tightening the surgical cable until the bone plate is secured to the bone, and crimping first and second ends of the surgical cable.
A more complete appreciation of the subject matter of the present invention and the various advantages thereof can be realized by reference to the following detailed description in which reference is made to the accompanying drawings in which:
Referring to
In a preferred embodiment, cable plug 10 comprises a cable retaining member 20 as shown for example in
As shown in
In this preferred embodiment, as shown particularly in
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Referring to the preferred embodiment shown in
In an alternate embodiment, cable retaining member 20 may also include a plurality of protrusions or recesses located around a circumference thereof, the plurality of protrusions or recesses adapted to couple to a plurality of corresponding protrusions or recesses around a circumference of fastener member 40. This configuration permits orientation of cable retaining member 20 with respect to fastening member about longitudinal axes 28 and 52. Similar to above, surgical cable 61 may therefore be retained within channel 26 of head portion 21 and oriented at a plurality of angles relative to the bone.
Alternatively, as shown in
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An alternate embodiment is shown in
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In yet another embodiment, cable plug 10 comprises a variation of cable retaining members 20, 20A, 20B, 20C, or 20D, as shown for example in
Alternatively still, as shown in
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as described by the appended claims.
Claims
1. A cable plug comprising:
- a cable retaining portion for receiving a surgical cable therein; and
- a fastening portion disposed from the cable retaining portion along a longitudinal axis of the cable plug, the fastening portion having an exterior surface broken by one or more slots, the exterior surface having a thread such that the fastening portion can be threaded into a hole in a bone plate.
2. The cable plug of claim 1, wherein the cable retaining portion has a base surface and at least one cable receiving member projecting upwardly from the base surface.
3. The cable plug of claim 2, wherein the at least one cable receiving member comprises at least one channel formed therein, the at least one channel being adapted to receive a portion of a cable therein.
4. The cable plug of claim 1, wherein the exterior surface of the fastening portion is broken by first and second slots defining first and second exterior surface portions configured to move toward and away from the longitudinal axis.
5. The cable plug of claim 4, wherein the first and second surface portions each have a portion of the thread.
6. The cable plug of claim 4, wherein movement of the first and second exterior surface portions with respect to the longitudinal axis allows the cable plug to be press-fit or threaded into the hole of the bone plate.
7. The cable plug of claim 1, wherein the fastening portion permits rotation of the cable plug with respect to the bone plate in a first or opposite second rotational direction about the longitudinal axis when the cable plug is in the hole of the bone plate.
8. The cable plug of claim 1, wherein the cable retaining portion is integral with the fastening portion.
9. The cable plug of claim 1, wherein the cable retaining portion has an engagement recess adapted to receive an insertion tool.
10. A cable plug comprising:
- a cable retaining portion for receiving a surgical cable therein; and
- a fastening portion disposed from the cable retaining portion along a longitudinal axis of the cable plug, the fastening portion having a deflectable sidewall and a thread on an exterior surface of the sidewall such that the fastening portion can be threaded into a hole in a bone plate.
11. The cable plug of claim 10, wherein the deflectable sidewall and the thread are broken by one or more slots such that at least one portion of the sidewall is moveable relative to at least another portion of the sidewall.
12. The cable plug of claim 11, wherein each of the one or more slots define a plane that is substantially parallel to the longitudinal axis of the cable plug.
13. The cable plug of claim 10, wherein the fastening portion forms a hollow annulus about the longitudinal axis.
14. The cable plug of claim 10, wherein the deflectable sidewall and the thread are broken by a plurality of slots so as to define a plurality of sidewall portions, each sidewall portion being configured to move toward and away from the longitudinal axis.
15. The cable plug of claim 10, wherein the cable retaining portion is integral with the fastening portion.
16. The cable plug of claim 10, further comprising at least one cable receiving member projecting upwardly from a base surface of the cable retaining portion so as to receive a portion of a cable therein.
17. A method for assembling a cable plug with a bone plate having a hole, the cable plug having a cable receiving portion disposed from a fastening portion along a longitudinal axis, the method comprising the steps of:
- placing a fastening portion of the plug adjacent the hole, the fastening portion having a broken sidewall with a plurality of sidewall portions and at least a portion of a thread on an exterior surface of each sidewall portion; and
- applying a force to the cable receiving portion of the cable plug to thread the fastening portion into the hole.
18. The method of claim 17, wherein an interior surface of the hole is threaded, the method further comprising applying a rotational force to the cable receiving portion so as to unthread the fastening portion out of the hole.
19. The method of claim 17, further comprising receiving a portion of an insertion tool in an engagement recess formed in the cable retaining portion.
20. The method of claim 17, further comprising the steps of:
- contacting a bone with the bone plate;
- wrapping a cable having a longitudinal axis around the bone and the bone plate;
- rotating the cable plug about the longitudinal axis of the cable plug until a cable retaining member formed on a base surface of the cable retaining potion is aligned with the longitudinal axis of the cable;
- receiving the cable in the cable retaining member;
- tightening the cable until the bone plate is secured to the bone; and
- crimping first and second ends of the cable to secure the cable.
Type: Application
Filed: Jun 24, 2015
Publication Date: Oct 15, 2015
Inventors: Aaron Forderer (Biel / Bienne), Nicolas Hainard (Fontainemelon), Axel Cremer (Lommiswil)
Application Number: 14/748,931