Tibial preparation apparatus and method

• US 5,704,941 A
• Filed: 11/03/1995
• Issued: 01/06/1998
• Est. Priority Date: 11/03/1995
• Status: Expired due to Term

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Osteonics Corporation (Stryker Corporation)
• Inventors: Wilson, Thomas G., Nedilsky, Andrij J., Jacober, John S., Trimmer, Kenneth H.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): REIP, DAVID OWEN
• Application Number:
  US08/552,594
• Time in Patent Office: 795 Days
• Field of Search: 606/86, 606/87, 606/88, 606/59, 623/20, 411/348
• US Class Current: 606/88
• CPC Class Codes: A61B 17/157 Cutting tibia

Abstract

Apparatus and method for the preparation of the proximal tibia for resection at a selected resection level utilize an external alignment shaft having an exposed upper end for the reception of a tibial resection guide over the exposed upper end for movement downwardly along the alignment shaft, securement to the alignment shaft at a resection location along the alignment shaft, and affixation to the proximal tibia at the resection level, the alignment shaft having an upper rod detachable from a lower tubular member for withdrawal of the upper rod from the lower tubular member, and for withdrawal upwardly from the tibial resection guide while the tibial resection guide is maintained affixed to the proximal tibia at the resection location, for full access of the tibial resection guide to a resection device to accomplish resection of the proximal tibia. A head at the upper end of the alignment shaft is anchored to the proximal tibia with fixation pins mounted for movement relative to the head for facilitating advancement and retraction of the fixation pins without disturbing the location of the tibial resection guide. The tibial resection guide is coupled to the alignment shaft with a securing member which projects sideways from the tibial resection guide so as to facilitate access to the tibial resection guide by the resection device. Selective attachment and detachment of a stylus assembly and the tibial resection guide is facilitated by a quick-connect mechanism, which assures positive location of a stylus for accurate location of the resection level.

Claims

1. An improvement in an apparatus used in connection with the implant of a prosthetic knee implant wherein the proximal tibia of a tibia is prepared for resection at a selected resection level for the reception of a tibial component of the prosthetic knee implant, the proximal tibia having a tibial eminence, the improvement comprising:

an external alignment shaft including an upper segment and a lower segment located along a common alignment axis, the upper segment being selectively movable along the alignment axis relative to the lower segment and having an exposed upper end;

a head at the exposed upper end of the upper segment, the head extending rearwardly for placement over the tibial eminence when the alignment shaft is located forward of the tibia;

anchoring means on the head for anchoring the head to the proximal tibia with the alignment shaft located forward of the tibia;

clamping means on the alignment shaft for clamping the upper segment and the lower segment of the alignment shaft against movement relative to one another subsequent to anchoring of the head to the proximal tibia;

alignment means for aligning the alignment shaft relative to the tibia subsequent to anchoring the head to the proximal tibia;

a tibial resection guide having coupling means for placement over the exposed upper end of the upper segment of the alignment shaft, from above the exposed upper end, to engage the tibial resection guide with the upper segment and enable movement of the tibial resection guide downwardly, over the exposed upper end, along the upper segment, subsequent to anchoring the head to the proximal tibia;

a stylus assembly having attachment means for attaching the stylus assembly to the tibial resection guide for movement with the tibial resection guide along the upper segment, the stylus assembly including a stylus engageable with the proximal tibia to locate the tibial resection guide at a resection location wherein the tibial resection guide is located for guiding resection at the selected resection level;

the coupling means of the tibial resection guide including securing means for selectively securing the tibial resection guide against movement along the upper segment when the tibial resection guide is located at the resection location; and

affixation means for affixing the tibial resection guide to the proximal tibia when the tibial resection guide is located at the resection location;

the securing means of the coupling means of the tibial resection guide being selectively releasable for releasing the securement between the tibial resection guide and the upper segment of the alignment shaft, subsequent to affixation of the tibial resection guide to the proximal tibia, and the clamping means of the alignment shaft being selectively releasable for releasing the upper segment of the alignment shaft for movement relative to the lower segment, segment, whereby the tibial resection guide can be independently connected to the upper segment of the alignment shaft while the head is anchored to the proximal tibia and the upper and lower segments of the alignment shaft are clamped together, and can be independently disconnected from the upper segment of the alignment shaft, subsequent to the affixation of the tibial resection guide, to enable withdrawal of the upper segment from the tibial resection guide and provide uninhibited access to the tibial resection guide for accomplishing resection at the selected resection level.

2. The invention of claim 1 wherein the anchoring means includes a first fixation pin for anchoring the head against anterior and posterior movements relative to the tibia, and a second fixation pin for anchoring the head against rotation about the first fixation pin, at least one of the first and second fixation pins being mounted in the head for selective movement in upward and downward directions relative to the head, between an advanced position wherein the moveable fixation pin extends downwardly from the head for extending into the proximal tibia, and a retracted position wherein the moveable fixation pin is retracted from the proximal tibia to enable selective release of the moveable fixation pin from the proximal tibia prior to withdrawal of the upper segment of the alignment shaft from the tibial resection guide to facilitate said withdrawal.

3. The invention of claim 2 wherein the moveable fixation pin is mounted for selective movement independent of the other fixation pin.

4. The invention of claim 2 including mounting means mounting the moveable fixation pin for sliding movement in the head between the advanced position and the retracted position.

5. The invention of claim 1 wherein the anchoring means includes:

a first fixation pin mounted in the head for selective movement in upward and downward directions relative to the head between an advanced position wherein the first fixation pin extends downwardly from the head for extending into the proximal tibia to anchor the head to the proximal tibia against upward movement of the head, and the upper segment of the alignment shaft, away from the proximal tibia, and a retracted position wherein the first fixation pin is retracted from the proximal tibia to release the head, and the upper segment of the alignment shaft, for upward movement relative to the proximal tibia; and

a second fixation pin mounted in the head for selective movement in upward and downward directions relative to the head between an advanced position wherein the second fixation pin extends downwardly from the head for extending into the proximal tibia to anchor the head to the proximal tibia against upward movement of the head, and the upper segment of the alignment shaft, away from the proximal tibia, and a retracted position wherein the second fixation pin is retracted from the proximal tibia to release the head, and the upper segment of the alignment shaft, for upward movement relative to the proximal tibia;

the first and second fixation pins being spaced from one another such that upon movement of both the first and second fixation pins to the respective advanced positions, rotation of the head about one of the first and second pins is precluded; and

upon movement of both the first and second fixation pins to the respective retracted positions, the fixation pins are retracted from the proximal tibia to enable selective release of the fixation pins from the proximal tibia prior to withdrawal of the upper segment of the alignment shaft from the tibial resection guide to facilitate said withdrawal.

6. The invention of claim 5 wherein the first fixation pin is spaced rearwardly of the alignment axis of the alignment shaft, and the second fixation pin is located between the first fixation pin and the alignment axis of the alignment shaft.

7. The invention of claim 6 wherein the first and second fixation pins are mounted in the head for selective movement independent of one another.

8. The invention of claim 5 including mounting means mounting the first and second fixation pins for sliding movement in the head between the respective advanced positions and retracted positions.

9. The invention of claim 1 wherein the attachment means for attaching the stylus assembly to the tibial resection guide comprises a quick-connect mechanism including an elongate socket extending downwardly into the tibial resection guide, an elongate plug on the stylus assembly, the plug being complementary to the socket and extending in the downward direction, a recess in the tibial resection guide, the recess communicating with the socket and extending transverse to the socket, a projection mounted in the plug for movement in transverse directions between an extended position, wherein the projection engages the recess to secure the plug in the socket, and a retracted position, wherein the projection is released from the recess to release the plug from the socket, and actuator means for selectively moving the projection between the advanced and retracted positions thereof.

10. The invention of claim 9 including biasing means for biasing the actuator means to move the projection into the extended position.

11. An improvement in an apparatus used in connection with the implant of a prosthetic knee implant wherein the proximal tibia of a tibia is prepared for resection for the reception of a tibial component of the prosthetic knee implant, the proximal tibia having a tibial eminence, the improvement comprising:

an external alignment shaft having an upper end;

a head at the upper end of the external alignment shaft, the head extending rearwardly for placement over the tibial eminence when the alignment shaft is located forward of the tibia; and

anchoring means on the head for anchoring the head to the proximal tibia with the alignment shaft located forward of the tibia;

the anchoring means including a first fixation pin for anchoring the head against anterior and posterior movements relative to the tibia, and a second fixation pin for anchoring the head against rotation about the first fixation pin, and mounting means capturing at least one of the first and second fixation pins in the head for selective movement in upward and downward directions relative to the head, between an advanced position wherein the moveable fixation pin extends downwardly from the head for extending into the proximal tibia, and a retracted position wherein the moveable fixation pin is retracted from the proximal tibia to enable selective release of the moveable fixation pin from the proximal tibia while the head remains in place over the tibial eminence and the moveable fixation pin remains captured in the head.

12. The invention of claim 11 wherein the moveable fixation pin is mounted for selective movement independent of the other fixation pin.

13. The invention of claim 11 wherein the mounting means captures the moveable fixation pin for sliding movement in the head between the advanced position and the retracted position.

14. An improvement in an apparatus used in connection with the implant of a prosthetic knee implant wherein the proximal tibia of a tibia is prepared for resection for the reception of a tibial component of the prosthetic knee implant, the proximal tibia having a tibial eminence, the improvement comprising:

an external alignment shaft having an upper end;

a head at the upper end of the external alignment shaft, the head extending rearwardly for placement over the tibial eminence when the alignment shaft is located forward of the tibia; and

anchoring means on the head for anchoring the head to the proximal tibia with the alignment shaft located forward of the tibia, the anchoring means including;

a first fixation pin mounted in the head for selective movement in upward and downward directions relative to the head between an advanced position wherein the first fixation pin extends downwardly from the head for extending into the proximal tibia to anchor the head to the proximal tibia against upward movement of the head, and the alignment shaft, away from the proximal tibia, and a retracted position wherein the first fixation pin is retracted from the proximal tibia to release the head, and the alignment shaft, for upward movement relative to the proximal tibia;

a second fixation pin mounted in the head for selective movement in upward and downward directions relative to the head between an advanced position wherein the second fixation pin extends downwardly from the head for extending into the proximal tibia to anchor the head to the proximal tibia against upward movement of the head, and the alignment shaft, away from the proximal tibia, and a retracted position wherein the second fixation pin is retracted from the proximal tibia to release the head, and the alignment shaft, for upward movement relative to the proximal tibia; and

mounting means for capturing the first and second fixation pins within the head;

the first and second fixation pins being spaced from one another such that upon movement of both the first and second fixation pins to the respective advanced positions, rotation of the head about one of the first and second pins is precluded; and

upon movement of both the first and second fixation pins to the respective retracted positions, the fixation pins are retracted from the proximal tibia to enable selective release of the fixation pins from the proximal tibia while the head remains in place over the tibial eminence and the first and second fixation pins remain captures in the head.

15. The invention of claim 14 wherein the first fixation pin is spaced rearwardly of the alignment shaft, and the second fixation pin is located between the first fixation pin and the alignment shaft.

16. The invention of claim 15 wherein the first and second fixation pins are mounted in the head for selective movement independent of one another.

17. The invention of claim 15 wherein the mounting means captures the first and second fixation pins for sliding movement in the head between the respective advanced positions and retracted positions.

18. An improvement in a method for implanting a prosthetic knee implant wherein the proximal tibia of a tibia is prepared for resection at a selected resection level for the reception of a tibial component of the prosthetic knee implant, the proximal tibia having a tibial eminence, the improvement comprising the following steps in order:

locating an external alignment shaft having an upper segment and a lower segment, forward of the tibia, the upper segment being selectively movable along an alignment axis relative to the lower segment and having an exposed upper end and a head at the exposed upper end of the upper segment, with the head extending rearwardly relative to the tibia;

placing the head over the tibial eminence when the alignment shaft is located forward of the tibia;

anchoring the head to the proximal tibia with anchoring means, with the alignment shaft located forward of the tibia;

clamping the upper segment and the lower segment of the alignment shaft against movement relative to one another subsequent to anchoring of the head to the proximal tibia;

aligning the alignment shaft relative to the tibia subsequent to anchoring the head to the proximal tibia;

placing a tibial resection guide having coupling means over the exposed upper end of the upper segment of the alignment shaft, from above the exposed upper end, to engage the tibial resection guide with the upper segment and enable movement of the tibial resection guide downwardly, over the exposed upper end, along the upper segment, subsequent to anchoring the head to the proximal tibia;

attaching a stylus assembly to the tibial resection guide for movement with the tibial resection guide along the upper segment, the stylus assembly including a stylus, and engaging the stylus with the proximal tibia to locate the tibial resection guide at a resection location wherein the tibial resection guide is located for resection at the selected resection level;

securing the tibial resection guide against movement along the upper segment when the tibial resection guide is located at the resection location;

affixing the tibial resection guide to the proximal tibia when the tibial resection guide is located at the resection location;

releasing the securement between the tibial resection guide and the upper segment of the alignment shaft, subsequent to affixation of the tibial resection guide to the proximal tibia;

releasing the upper segment of the alignment shaft for movement relative to the lower segment, subsequent to the affixation of the tibial resection guide; and

withdrawing the upper segment from the tibial resection guide to provide uninhibited access to the tibial resection guide for accomplishing resection at the selected resection level.

19. The invention of claim 18 wherein the anchoring means includes a first fixation pin for anchoring the head against anterior and posterior movements relative to the tibia, and a second fixation pin for anchoring the head against rotation about the first fixation pin, at least one of the first and second fixation pins being mounted in the head for selective movement in upward and downward directions relative to the head, independent of one another, between an advanced position wherein the moveable fixation pin extends downwardly from the head for extending into the proximal tibia, and a retracted position wherein the moveable fixation pin is retracted from the proximal tibia, the improvement including advancing the first fixation pin into the proximal tibia to first anchor the head to the proximal tibia against anterior and posterior movements relative to the proximal tibia, with the head seated upon the proximal tibia, and subsequently advancing the second fixation pin into the proximal tibia to anchor the head against rotational movement about the first fixation pin.

20. The invention of claim 18 wherein the anchoring means includes a first fixation pin for anchoring the head against anterior and posterior movements relative to the tibia, and a second fixation pin for anchoring the head against rotation about the first fixation pin, the first and second fixation pins being mounted in the head for selective movement in upward and downward directions relative to the head, between an advanced position wherein the fixation pins extend downwardly from the head for extending into the proximal tibia, and a retracted position wherein the fixation pins are retracted from the proximal tibia, the improvement including first seating the head upon the proximal tibia, and then advancing the fixation pins sequentially into the proximal tibia to anchor the head to the proximal tibia.

21. The invention of claim 18 wherein the anchoring means includes a first fixation pin for anchoring the head against anterior and posterior movements relative to the tibia, and a second fixation pin for anchoring the head against rotation about the first fixation pin, at least one of the first and second fixation pins being mounted in the head for selective movement in upward and downward directions relative to the head, between an advanced position wherein the moveable fixation pin extends downwardly from the head for extending into the proximal tibia, and a retracted position wherein the moveable fixation pin is retracted from the proximal tibia, the improvement including releasing the moveable fixation pin from the proximal tibia prior to withdrawal of the upper segment of the alignment shaft from the tibial resection guide to facilitate said withdrawal.

22. The invention of claim 18 wherein the anchoring means includes a first fixation pin mounted in the head for selective movement in upward and downward directions relative to the head between an advanced position wherein the first fixation pin extends downwardly from the head for extending into the proximal tibia to anchor the head to the proximal tibia against upward movement of the head, and the upper segment of the alignment shaft, away from the proximal tibia, and a retracted position wherein the first fixation pin is retracted from the proximal tibia to release the head, and the upper segment of the alignment shaft, for upward movement relative to the proximal tibia, and a second fixation pin mounted in the head for selective movement in upward and downward directions relative to the head between an advanced position wherein the second fixation pin extends downwardly from the head for extending into the proximal tibia to anchor the head to the proximal tibia against upward movement of the head, and the upper segment of the alignment shaft, away from the proximal tibia, and a retracted position wherein the second fixation pin is retracted from the proximal tibia to release the head, and the upper segment of the alignment shaft, for upward movement relative to the proximal tibia, the first and second fixation pins being spaced from one another such that upon movement of both the first and second fixation pins to the respective advanced positions, rotation of the head about one of the first and second pins is precluded, the improvement including retracting the fixation pins from the proximal tibia to release the fixation pins from the proximal tibia prior to withdrawal of the upper segment of the alignment shaft from the tibial resection guide to facilitate said withdrawal without disturbing the affixation of the tibial resection guide on the proximal tibia.

23. The invention of claim 18 wherein the stylus assembly is attached to the tibial resection guide prior to placing the tibial resection guide over the exposed upper end of the upper segment of the alignment shaft to engage the tibial resection guide with the upper segment.

24. An improvement in a method used in connection with the implant of a prosthetic knee implant wherein the proximal tibia of a tibia is prepared for resection at a selected resection level for the reception of a tibial component of the prosthetic knee implant, the proximal tibia having a tibial eminence, the improvement comprising:

locating an external alignment shaft forward of the tibia, the external alignment shaft having an upper end, and a head at the upper end of the external alignment shaft, the head extending rearwardly for placement over the tibial eminence when the alignment shaft is located forward of the tibia; and

anchoring the head to the proximal tibia with anchoring means, with the alignment shaft located forward of the tibia, the anchoring means including a first fixation pin for anchoring the head against anterior and posterior movements relative to the tibia, and a second fixation pin for anchoring the head against rotation about the first fixation pin, at least one of the first and second fixation pins being captured in the head for selective movement in upward and downward directions relative to the head, between an advanced position wherein the moveable fixation pin extends downwardly from the head for extending into the proximal tibia, and a retracted position wherein the moveable fixation pin is retracted from the proximal tibia while the movable fixation pin remains captured in the head, the improvement including advancing one of the first and second fixation pins into the proximal tibia to first anchor the head to the proximal tibia against anterior and posterior movements relative to the proximal tibia, with the head seated upon the proximal tibia, and subsequently advancing the other of the first and second fixation pins into the proximal tibia to anchor the head against rotational movement about the said one of the first and second fixation pins.

25. The invention of claim 24 wherein the first fixation pin anchors the head against anterior and posterior movements relative to the tibia, and the second fixation pin anchors the head against rotation about the first fixation pin, each of the first and second fixation pins being mounted in the head for selective movement in upward and downward directions relative to the head, between an advanced position wherein the fixation pins extend downwardly from the head for extending into the proximal tibia, and a retracted position wherein the fixation pins are retracted from the proximal tibia, the improvement including first seating the head upon the proximal tibia, and then advancing the fixation pins sequentially into the proximal tibia to anchor the head to the proximal tibia.

26. The invention of claim 24 including retracting said one of the first and second fixation pins to release said one of the first and second fixation pins from the proximal tibia while maintaining the head seated upon the proximal tibia, and subsequently withdrawing the head from the proximal tibia.

27. The invention of claim 24 wherein the first fixation pin is mounted in the head for selective movement in upward and downward directions relative to the head between an advanced position wherein the first fixation pin extends downwardly from the head for extending into the proximal tibia to anchor the head to the proximal tibia against upward movement of the head, and the alignment shaft, away from the proximal tibia, and a retracted position wherein the first fixation pin is retracted from the proximal tibia to release the head, and the alignment shaft, for upward movement relative to the proximal tibia, and the second fixation pin is mounted in the head for selective movement in upward and downward directions relative to the head between an advanced position wherein the second fixation pin extends downwardly from the head for extending into the proximal tibia to anchor the head to the proximal tibia against upward movement of the head, and the alignment shaft, away from the proximal tibia, and a retracted position wherein the second fixation pin is retracted from the proximal tibia to release the head, and the alignment shaft, for upward movement relative to the proximal tibia, the first and second fixation pins being spaced from one another such that upon movement of both the first and second fixation pins to the respective advanced positions, rotation of the head about one of the first and second pins is precluded, the improvement including retracting the fixation pins from the proximal tibia to release the fixation pins from the proximal tibia while maintaining the head seated upon the proximal tibia, and subsequently withdrawing the head from the proximal tibia.