EXPANDABLE INTRAMEDULLARY ROD

• US 20110077651A1
• Filed: 09/27/2010
• Published: 03/31/2011
• Est. Priority Date: 09/28/2009
• Status: Active Grant

• Current Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Roberts, Shanon N., May, Justin J., Pacelli, Nicolas J., Gray, Andrew L., Murphy, Daniel P., Lozier, Antony J.
• Granted Patent: US 8,545,499 B2
• Time in Patent Office: Days
• US Class Current: 606/62
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/7258 with laterally expanding parts, e.g. for gripping the bone

Abstract

An expandable rod is provided that is sized for insertion into a patient'"'"'s bone. A method for using the expandable rod to prepare the patient'"'"'s bone to receive an orthopedic implant is also provided. The expandable rod is adjustable between a first, contracted state and a second, expanded state, the expansion member expanding radially outwardly from the contracted state to the expanded state.

Claims

1. An expandable rod sized for insertion into a patient'"'"'s bone, the expandable rod comprising:

a shaft having a first end and a second end;

an expansion member coupled to the shaft and adjustable between a first, contracted state and a second, expanded state, the expansion member expanding radially outwardly from the contracted state to the expanded state, the expansion member including a first expansion segment and a second expansion segment, the first expansion segment having a higher slenderness ratio than the second expansion segment; and

an actuator moveably coupled to the shaft to adjust the expansion member between the contracted state and the expanded state.

2. The expandable rod of claim 1, wherein the first expansion segment expands from the contracted state to the expanded state before the second expansion segment.

3. The expandable rod of claim 1, wherein the expansion member is a braided construct.

4. The expandable rod of claim 1, wherein the first expansion segment has a first length and the second expansion segment has a second length, the first length exceeding the second length.

5. The expandable rod of claim 1, wherein, when the expansion member is in the expanded state, the first expansion segment has a larger diameter than the second expansion segment.

6. The expandable rod of claim 1, wherein the expansion member further includes at least a third expansion segment having a lower slenderness ratio than the second expansion segment, the first, second, and third expansion segments expanding sequentially from the contracted state to the expanded state.

7. The expandable rod of claim 1, wherein the first expansion segment is nearer to the first end of the shaft than the second expansion segment.

8. The expandable rod of claim 1, further comprising a non-expandable, intermediate segment located axially between the first and second expansion segments.

9. The expandable rod of claim 8, wherein the intermediate segment comprises an annular band that surrounds the expansion member to restrict expansion of the expansion member between the first and second expansion segments.

10. The expandable rod of claim 9, wherein the annular band is moveable axially along the expansion member to adjust a length of at least one of the first and second expansion segments.

11. The expandable rod of claim 1, further comprising a guide component coupled to the expandable rod, the guide component referencing an exterior surface of the patient'"'"'s bone when the expandable rod is positioned within an intramedullary canal of the patient'"'"'s bone.

12. The expandable rod of claim 1, further comprising a locking mechanism that locks the actuator relative to the shaft, the locking mechanism configured to lock the expansion member in at least one of the contracted state and the expanded state.

13. An expandable rod sized for insertion into a patient'"'"'s bone, the expandable rod comprising:

an expansion member having a first end and a second end;

a shaft coupled to the expansion member; and

an actuator moveably coupled to the shaft, the actuator configured to move the second end of the expansion member axially toward the first end of the expansion member to compress the expansion member axially and to expand the expansion member radially outwardly, the first end of the expansion member expanding before the second end of the expansion member.

14. The expandable rod of claim 13, wherein the expansion member defines a bore and the shaft extends through the bore of the expansion member.

15. The expandable rod of claim 13, wherein the first end of the expansion member is axially fixedly coupled to the shaft and the second end of the expansion member is axially movably coupled to the shaft.

16. The expandable rod of claim 13, wherein the first end of the expansion member includes a first expansion segment and the second end of the expansion member includes a second expansion segment, the expansion member further including an non-expandable, intermediate segment located axially between the first and second expansion segments.

17. The expandable rod of claim 13, wherein the first end of the expansion member expands radially outwardly a greater distance than the second end of the expansion member.

18. The expandable rod of claim 13, further comprising a locking mechanism that locks the actuator relative to the shaft, the locking mechanism configured to lock the second end of the expansion member in a fixed axial position relative to the first end of the expansion member.

19. A method of preparing a patient'"'"'s bone to receive an orthopedic implant, the method comprising the steps of:

providing an expandable rod that includes a shaft and an expansion member having a first end and a second end, the expansion member of the expandable rod adjustable between a first, contracted state and a second, expanded state;

inserting the expandable rod into the patient'"'"'s bone with the expansion member in the contracted state;

after the inserting step, expanding the expansion member radially outwardly to the expanded state, the first end of the expansion member expanding before the second end of the expansion member, at least a portion of the shaft remaining outside of the patient'"'"'s bone;

coupling a guide component to the portion of the shaft remaining outside of the patient'"'"'s bone; and

resecting the patient'"'"'s bone using the guide component.

20. The method of claim 19, wherein the inserting step comprises inserting the first end of the expansion member further into the patient'"'"'s bone than the second end of the expansion member, the first end of the expansion member expanding before the second end of the expansion member to pull the expansion member into the patient'"'"'s bone during the expanding step.

21. The method of claim 19, wherein the expanding step comprises pulling the shaft in a direction away from the patient'"'"'s bone.

22. The method of claim 19, wherein the resecting step comprises at least one of cutting, milling, and drilling an exterior surface of the patient'"'"'s bone.