Device and method for inserting a prosthetic knee

• US 6,554,837 B1
• Filed: 02/13/2001
• Issued: 04/29/2003
• Est. Priority Date: 06/29/1998
• Status: Expired due to Term

• Current Assignee: Plus Endoprothetik AG (Smith & Nephew PLC)
• Original Assignee: Plus Endoprothetik AG (Smith & Nephew PLC)
• Inventors: Hauri, Bernard, Hauri, Thomas, Berner, Werner
• Primary Examiner(s): Robert, Eduardo C.
• Application Number:
  US09/719,109
• Time in Patent Office: 805 Days
• Field of Search: 606/87, 606/88, 606/89, 606/82
• US Class Current: 606/87
• CPC Class Codes: A61B 17/154 for preparing bone for knee prosthesis
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 2090/3916 Bone tissue
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery

Abstract

A device for localizing and executing resection cuts on the femur (1) for preparing an implantation of a total endoprosthetic knee joint is provided. The device includes a reference device (5) adapted to be releasably attachable to the femur (1) in the distal area of the femur (1). Alignment of the reference device (5) relative to the femur (1) should be accurately positionable. An adjustment device (10) is connected to the reference device (5). The adjustment device (10) is movable relative to the reference device (5) and is provided with a linearly movable base part (10g) for the attachment of an instrument (11, 14). A first drive device (5v, 21) linearly moves the adjustment device (10) relative to the reference device (5) in the direction (10b) of a first axis (X) of a system of coordinates (X, Y, Z). A second drive device (10f, 17) linearly moves the base part (10g) in the direction (10d) of another, second axis (Y) of said system of coordinates (X, Y, Z). Both the first and second drive devices (5v, 21; 10f, 17) include a motor drive.

Claims

1. A device for localizing and executing resection cuts on a femur (1) for preparing an implantation of a total endoprosthetic knee joint, comprising a reference device (5) releasably attachable to a distal area of the femur (1), alignment of the reference device relative to the femur (1) being accurately positionable, an adjustment device (10) connected to the reference device (5) being movable relative to the reference device and provided with a linearly movable base part (10g) for the attachment of an instrument, a first drive device (5v, 21) for linearly moving the adjustment device (10) relative to the reference device (5) in a direction (10b) of a first axis (X) of a system of coordinates (X, Y, Z), a second drive device (10f, 17) for linearly moving the base part (10g) in a direction (10b) of another axis (y) of the system of coordinates (X, Y, Z), both the first and second drive devices comprising a motor drive.

2. A device according to claim 1, wherein both the first and second drive devices comprise an electromotive drive (17d).

3. A device according to claim 2, wherein the electromotive drives (17d) are controlled by a computer (16), to which a screen (16a) and an input keyboard (16b) are assigned.

4. A device according to claim 1, wherein the reference device (5) determines at least the first axis (X) as extending essentially in the direction of a weight-bearing axis (19b) of the femur (1) when the reference device (5) is aligned relative to the femur.

5. A device according to claim 4, wherein the adjustment device (10) determines the second axis (Y), the first and second axes (X, Y) extending perpendicular to each other and enclosing a plane in which the weight-bearing axis (19b) essentially lies.

6. A device according to claim 1, wherein the reference device (5) has a linear guide (5z) extending in the direction (10b) of the first axis (X) of the system of coordinates (X, Y, Z), the adjustment device (10) comprises a rod which fits into the linear guide (5z) and can be displaced in the direction of the first axis (X), and the first drive device (5v, 21) acts on the rod (10a) and permits a movement of the rod (10a) relative to the reference device (5).

7. A device according to claim 6, wherein the rod is a toothed rod.

8. A device according to claim 1, wherein at least one measurement sensor (10l) is arranged detachably on the base part (10g) of the adjustment device (10) in order to detect the position of the condyles (1a) of the femur (1).

9. A device according to claim 1, wherein an anchoring part (3) is provided which can be attached securely on the femur (1), and in that the anchoring part (3) and the reference device (5) together form a releasable catch.

10. A device according to claim 9, wherein the anchoring part (3) comprises a base platform (3h) with a longitudinal axis (3s) and at least two legs (3k, 3i) mounted displaceably relative to the base platform (3h) and arranged opposite each other approximately perpendicular to the longitudinal axis (3s), the legs (3k, 3i) having projecting points (3q) arranged extending toward the femur (1) and capable of penetrating into a femoral bone.

11. A device according to claim 9, wherein the anchoring part (3) has a three-point support (3a) which is intended to bear of the femur (1).

12. A device according to claim 9, wherein the releasable catch is a bayonet catch.

13. A device according to claim 1, wherein the reference device (5) has a base part (5a) which can be detachably fixed in the distal area of the femur (1), and a reference body (5o) is connected to the base part (5a), whose alignment can be accurately positioned relative to the femur (1).

14. A device according to claim 13, wherein an actuating means (5l, 5r) acting between the reference body (5o) and the base part (5a) is provided for fixing a mutual position between the reference body and the base part.

15. A device according to claim 13, wherein the base part (5a) is mounted to pivot relative to the reference body (5o) at least about an axis (5i) which extends essentially in the direction of a weight-bearing axis (19b) of the femur (1) when the base part (5a) is fixed on the femur.

16. A device according to claim 13, wherein the reference body is connected to the base part in one of an articulated and displaceable manner.

17. A device according to claim 1, wherein an alignment rod (7) is mounted extending along the first axis (X) and can pivot about a pivot axis extending in another direction (Z) of another axis of the system of coordinates (X, Y, Z) on the reference body (5o).

18. A device according to claim 1, wherein the first drive device (5v, 21) is arranged directly on the reference device (5).

19. A device according to claim 1, wherein the first drive device (5v, 21) is arranged at a distance from the reference device (5) and is operationally connected to the reference device (5) via a flexible shaft (17a).

20. A device according to claim 1, wherein the second drive device (10f, 17) is arranged directly on the adjustment device (10).

21. A device according to claim 1, wherein the second drive device (10f, 17) is arranged at a distance from the adjustment device (10) and is operationally connected to the adjustment device (10) via a flexible shaft (17a).

22. A device according to claim 1, wherein a sawing jig (11) for guiding a saw blade (12) is secured on the base part (10g) of the adjustment device (10).

23. A device according to claim 1, wherein a cutting device (14) is secured on the base part (10g) of the adjustment device (10).

24. A device according to claim 23, wherein the cutting device is a sawing device (14) having a saw blade (12).

25. A device according to claim 24, wherein the saw blade (12) of the sawing device (14) defines a saw blade plane, the sawing device (14) is secured with a connection means (13) on the base part (10g) of the adjustment device (10), the connection means (13) and the sawing device (14) being designed so that the saw blade (12) is mounted to be displaceable exclusively in the saw blade plane.

26. A device according to claim 25, wherein the connection means (13) is designed as one of a swivel arm (13f, 13h) and a double-axis telescopic guide.

27. A device according to claim 25, wherein a hand grip (14a) is articulated on the sawing device (14) to assume different spatial positions whereby the spatial position of the hand grip (14a) does not influence alignment of the saw blade (12) relative to a cutting plane.

28. A device according to claim 25, wherein the connection means (13) is connected to the base part (10g) of the adjustment device (10) via a pivot adjustment device (13q) having a pivot axis (13e), and in that the pivot adjustment device (13q) permits swiveling of the connection means (13) relative to the adjustment device (10) about a pivot angle (13m).

29. A device according to claim 28, wherein the pivot adjustment device is designed as a mechanical locking device (13q) which has stop elements (13b, 13o) in order to stop the pivot angle of the pivot axis (13e) in predetermined positions.

30. A device according to claim 28, wherein the pivot adjustment device (13q) comprises a drive motor making it possible to set a predetermined pivot angle.

31. A device according to claim 30, wherein the pivot adjustment device includes a pivot angle sensor to detect the pivot angle.

32. A method for performing resection cuts on a femur (1) comprising:

fixing a reference device (5) on a distal end of the femur (1), aligning the reference device relative to a direction of extent of the femur (1), displaceably connecting a sawing jig (11), for guiding a saw blade (12), to the aligned reference device (5), guiding the saw blade guided in the sawing jig in an alignment position defining the direction of extent of a resection cut to be made, carrying out the resection cut with the saw blade (12) guided in the alignment position.