Method and apparatus for implanting a prosthetic device

• US 6,554,838 B2
• Filed: 05/31/2001
• Issued: 04/29/2003
• Est. Priority Date: 05/31/2001
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Inventors: Liepins, Imants, McGovern, Michael J., OʼHehir, Anthony, Serpe, Louie
• Primary Examiner(s): Robert, Eduardo C.
• Application Number:
  US09/871,153
• Publication Number:
  US 20020183760A1
• Time in Patent Office: 698 Days
• Field of Search: 606/79, 606/80, 606/87, 606/88, 606/89
• US Class Current: 606/87
• CPC Class Codes: A61B 17/1675 for the knee
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2017/1602 Mills
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/3895 unicompartimental
• CPC Class Codes: A61F 2310/00011 Metals or alloys

Abstract

Method and apparatus for preparing a seating surface of prescribed depth, contour configuration and area delineated by a prescribed peripheral boundary extending along the bone of a natural joint at which a prosthetic device is to be implanted includes positioning a guide on the bone, the guide having a guide slot following a path geometrically similar to the peripheral boundary of the seating surface, inserting a cutting device altitudinally through the guide slot at any selected location along the path of the guide slot, and translating the cutting device along the guide slot to cut an outline groove in the bone coincident with the peripheral boundary of the seating surface. The guide then is removed from the bone, and portions of the bone lying within the area delineated by the outline groove are removed to establish the seating surface.

Claims

1. Apparatus for preparing a seating surface of prescribed depth, contour configuration and area delineated by a prescribed peripheral boundary extending along the bone of a natural joint at which a prosthetic device is to be implanted, the bone having been provided with at least a partially prepared site for locating and seating a component part of the prosthetic device at the seating surface, the apparatus comprising:

a depth, contouring and area guide block having longitudinally opposite first and second ends, laterally opposite first and second sides, an upper locator surface and a lower guide locating surface;

at least a portion of the upper locator surface having a profile contour configuration essentially matching a corresponding portion of the contour configuration of the seating surface;

a holding arrangement integral with the guide block for holding the guide block on the bone at the site with the guide block placed at a predetermined location and orientation relative to the bone;

a guide slot passing altitudinally through the guide block from the upper locator surface to the lower guide locating surface, the guide slot having a length, a laterally outer locator edge extending along a path geometrically similar to the peripheral boundary of the seating surface, a laterally inner edge and a lateral width between the outer locator edge and the inner edge; and

a cutting device for reception within the guide slot, the cutting device having a cutting axis for extending altitudinally when the cutting device is received within the guide slot, an axial cutting surface for rotation about the cutting axis, the axial cutting surface having a near end and a far end, a radial cutting surface transverse to the axial cutting surface at the far end, a radial bearing surface located at a predetermined axial distance from the radial cutting surface, and an axial bearing surface located axially between the radial bearing surface and the near end of the axial cutting surface;

the axial cutting surface having a diameter less than the lateral width of the guide slot, the axial bearing surface having a diameter less than the lateral width of the guide slot, and the radial bearing surface having a diameter greater than the lateral width of the guide slot, the diameters of the axial cutting surface, the axial bearing surface and the radial bearing surface having relative dimensions such that upon reception of the cutting device within the guide slot, the cutting device is capable of insertion axially into the guide slot in an altitudinal direction at any selected location along the length of the guide slot, the axial bearing surface follows the contour configuration of the outer locator edge of the guide slot to locate the axial cutting surface along the peripheral boundary of the seating surface while the radial bearing surface follows the upper locator surface, with the radial bearing surface overlying the outer locator edge and the inner edge of the guide slot to stabilize and locate the radial cutting surface at the prescribed depth of the seating surface.

2. The apparatus of claim 1 wherein:

the guide slot includes a first leg extending longitudinally from the first end of the guide block toward the second end of the guide block, adjacent the first side of the guide block, and a second leg extending longitudinally from the first end toward the second end of the guide block, adjacent the second side of the guide block; and

the upper locator surface includes a first portion adjacent the first leg and spaced altitudinally from the lower guide locating surface a first altitudinal distance such that engagement of the radial bearing surface with the first portion of the upper locator surface will locate the radial cutting surface in place for establishing a first predetermined depth along a corresponding first portion of the seating surface, and a second portion adjacent the second leg and spaced altitudinally from the lower guide locating surface a second altitudinal distance different from the first altitudinal distance such that engagement of the radial bearing surface with the second portion of the upper locator surface will locate the radial cutting, surface in place for establishing a second predetermined depth along a corresponding second portion of the seating surface.

3. The apparatus of claim 2 for use where the natural joint is a knee joint, the prosthetic device is a prosthetic knee joint, the component part is a unicondylar femoral component, and the bone at the site includes a trochlear groove and a femoral condyle, and wherein the guide block is to be placed at the site with the first portion of the upper locator surface nearer to the trochlear groove and the second portion of the upper locator surface further from the trochlear groove, the apparatus including an improvement wherein the first altitudinal distance is less than the second altitudinal distance.

4. The apparatus of claim 3 wherein the guide slot includes a third leg extending laterally from the first leg to the second leg adjacent the second end of the guide block.

5. The apparatus of claim 3 for use where the site includes an essentially planar posterior surface formed on the femoral condyle, the apparatus including an improvement wherein the lower guide locating surface includes an essentially planar surface portion extending in an altitudinal direction for engaging the posterior surface to locate and orient the guide block on the bone at the site.

6. The apparatus of claim 1 wherein:

the guide slot includes a first leg extending longitudinally from the first end of the guide block toward the second end of the guide block, adjacent the first side of the guide block, and a second leg extending longitudinally from the first end toward the second end, adjacent the second side of the guide block; and

the holding arrangement includes a post placed laterally intermediate the first and second legs and projecting altitudinally downwardly from the lower guide locating surface.

7. The apparatus of claim 1 wherein:

the guide slot includes a first leg extending longitudinally from the first end of the guide block toward the second end of the guide block, adjacent the first side of the guide block, and a second leg extending longitudinally from the first end toward the second end, adjacent the second side of the guide block; and

the holding arrangement includes a fin placed laterally intermediate the first and second legs, projecting altitudinally downwardly from the lower guide locating surface, and extending longitudinally between the first and second ends of the guide block.

8. The apparatus of claim 7 wherein the holding arrangement includes a post placed laterally intermediate the first and second legs and projecting altitudinally downwardly from the lower guide locating surface.

9. The apparatus of claim 1 wherein the diameter of the axial cutting surface is less than the diameter of the axial bearing surface, and the outer locator edge of the guide slot extends adjacent the peripheral boundary of the seating surface, outside the area of the seating surface.

10. The apparatus of claim 9 wherein the cutting surface comprises a cylindrical cutting surface, and the axial bearing surface comprises a cylindrical bearing surface coaxial with the cylindrical cutting surface.

11. An improvement in an apparatus for preparing a seating surface of prescribed depth, contour and area placed within a prescribed peripheral boundary extending along the bone of a natural joint at which a prosthetic device is to be implanted, the bone having been provided with at least a partially prepared site for locating and seating a component part of the prosthetic device at the seating surface, the apparatus including a depth, contouring and area guide for guiding a cutting device to be received within the guide, the cutting device having a cutting axis for extending altitudinally within the guide, an axial cutting surface for rotation about the cutting axis, the axial cutting surface having a first diameter, a near end and a far end, a radial cutting surface transverse to the axial cutting surface at the far end, a radial bearing surface having a second diameter and being located at a predetermined axial distance from the radial cutting surface, and an axial bearing surface having a third diameter and being located axially between the radial bearing surface and the near end of the axial cutting surface, the improvement comprising:

a depth, contouring and area guide block having longitudinally opposite first and second ends, laterally opposite first and second sides, an upper locator surface and a lower guide locating surface;

at least a portion of the upper locator surface having a profile contour configuration essentially matching a corresponding portion of the contour configuration of the seating surface;

a holding arrangement integral with the guide block for holding the guide block on the bone at the site with the guide block placed at a predetermined location and orientation relative to the bone; and

a guide slot extending altitudinally through the guide block from the upper locator surface to the lower guide locating surface, the guide slot having a length, a laterally outer locator edge following a path geometrically similar to the peripheral boundary of the seating surface, a laterally inner edge and a lateral width between the outer locator edge and the inner edge;

the lateral width of the guide slot being greater than each of the first and third diameters and less than the second diameter with the first, second and third diameters having relative dimensions such that upon reception of the cutting device within the guide slot, the cutting device is capable of insertion axially into the guide slot in an altitudinal direction at any selected location along the length of the guide slot, the axial bearing surface follows the outer locator edge of the guide slot to locate the axial cutting surface along the peripheral boundary of the seating surface while the radial bearing surface follows the upper locator surface, with the radial bearing surface overlying the outer locator edge and the inner edge of the guide slot to stabilize and locate the radial cutting surface at the prescribed depth of the seating surface.

12. The improvement of claim 11 wherein:

the guide slot includes a first leg extending longitudinally from the first end of the guide block toward the second end of the guide block, adjacent the first side of the guide block, and a second leg extending longitudinally from the first end toward the second end of the guide block, adjacent the second side of the guide block; and

the upper locator surface includes a first portion adjacent the first leg and spaced altitudinally from the lower guide locating surface a first altitudinal distance such that engagement of the radial bearing surface with the first portion of the upper locator surface will locate the radial cutting surface in place for establishing a first predetermined depth along a corresponding first portion of the seating surface, and a second portion adjacent the second leg and spaced altitudinally from the lower guide locating surface a second altitudinal distance different from the first altitudinal distance such that engagement of the radial bearing surface with the second portion of the upper locator surface will locate the radial cutting surface in place for establishing, a second predetermined depth along a corresponding second portion of the seating surface.

13. The improvement of claim 12 for use where the natural joint is a knee joint, the prosthetic device is a prosthetic knee joint, the component part is a unicondylar femoral component, the bone at the site includes a trochlear groove and a femoral condyle, and wherein the guide block is to be placed at the site with the first portion of the upper locator surface nearer to the trochlear groove and the second portion of the upper locator surface further from the trochlear groove, the improvement including a construction wherein the first altitudinal distance is less than the second altitudinal distance.

14. The improvement of claim 13 wherein the guide slot includes a third leg extending laterally from the first leg to the second leg adjacent the second end of the guide block.

15. The improvement of claim 13 for use where the site includes an essentially planar posterior surface formed on the femoral condyle, the improvement including a construction wherein the lower guide locating surface includes an essentially planar surface portion extending in an altitudinal direction for engaging the anterior surface to locate and orient the guide block on the bone at the site.

16. The improvement of claim 11 wherein:

the guide slot includes a first leg extending longitudinally from the first end of the guide block toward the second end of the guide block, adjacent the first side of the guide block, and a second leg extending longitudinally from the first end toward the second end, adjacent the second side of the guide block; and

the holding arrangement includes a post placed laterally intermediate the first and second legs and projecting altitudinally downwardly from the lower guide locating surface.

17. The improvement of claim 11 wherein:

the guide slot includes a first leg extending longitudinally from the first end of the guide block toward the second end of the guide block, adjacent the first side of the guide block, and a second leg extending longitudinally from the first end toward the second end, adjacent the second side of the guide block; and

the holding arrangement includes a fin placed laterally intermediate the first and second legs, projecting altitudinally downwardly from the lower guide locating surface, and extending longitudinally between the first and second ends of the guide block.

18. The improvement of claim 17 wherein the holding arrangement includes a post placed laterally intermediate the first and second legs and projecting altitudinally downwardly from the lower guide locating surface.

19. An improvement in an apparatus for preparing a seating surface of prescribed depth, contour and area delineated by a prescribed peripheral boundary extending along the bone of a natural joint at which a prosthetic device is to be implanted, the bone having been provided with at least a partially prepared site for locating and seating a component part of the prosthetic device at the seating surface, the apparatus including a depth, contouring and area guide block having longitudinally opposite first and second ends, laterally opposite first and second sides, an upper locator surface and a lower guide locating surface, at least a portion of the upper locator surface having a profile contour configuration essentially matching a corresponding portion of the contour configuration of the seating surface, a holding arrangement integral with the guide block for holding the guide block on the bone at the site with the guide block placed at a predetermined location and orientation relative to the bone, a guide slot extending altitudinally through the guide block from the upper locator surface to the lower guide locating surface, the guide slot having a length, a laterally outer locator edge following a path geometrically similar to the peripheral boundary of the seating surface, a laterally inner edge and a lateral width between the outer locator edge and the inner edge, the improvement comprising:

a cutting device for reception within the guide slot, the cutting device including

a cutting axis for extending altitudinally when the cutting device is received within the guide slot;

an axial cutting surface for rotation about the cutting axis, the axial cutting surface having a near end and a far end;

a radial cutting surface transverse to the axial cutting surface at the far end;

a radial bearing surface located at a predetermined axial distance from the radial cutting surface; and

an axial bearing surface located axially between the radial bearing surface and the near end of the axial cutting surface;

the axial cutting surface having a diameter less than the lateral width of the guide slot, the axial bearing surface having a diameter less than the lateral width of the guide slot, and the radial bearing surface having a diameter greater than the lateral width of the guide slot, the diameters of the axial cutting surface, the axial bearing surface and the radial bearing surface having relative dimensions such that upon reception of the cutting device within the guide slot, the cutting device is capable of insertion axially into the guide slot in an altitudinal direction at any selected location along the length of the guide slot, the axial bearing surface follows the outer locator edge of the guide slot to locate the axial cutting surface along the peripheral boundary of the seating surface while the radial bearing surface follows the upper locator surface, with the radial bearing surface overlying the outer locator edge and the inner edge of the guide slot to stabilize and locate the radial cutting surface at the prescribed depth of the seating surface.

20. The improvement of claim 19 wherein the diameter of the axial cutting surface is less than the diameter of the axial bearing surface, and the outer locator edge of the guide slot extends adjacent the peripheral boundary of the seating surface, outside the area of the seating surface.

21. The improvement of claim 20 wherein the cutting surface comprises a cylindrical cutting surface, and the axial bearing surface comprises a cylindrical bearing surface coaxial with the cylindrical cutting surface.

22. A method of preparing a seating surface of prescribed depth, contour and area delineated by a prescribed peripheral boundary extending along the bone of a natural joint at which a prosthetic device is to be implanted, the bone having been provided with at least a partially prepared site for locating and seating a component part of the prosthetic device at the seating surface, the method comprising the steps of:

positioning a depth, contouring and area guide on the bone at the site, the guide including a guide slot having a length following a path geometrically similar to the peripheral boundary of the seating surface, the length including longitudinal length portions spaced apart laterally;

engaging a cutting device with the guide by inserting the cutting device altitudinally through the guide slot at any selected location along the path of the guide slot;

translating the cutting device along the length of the guide slot to cut an outline groove in the bone coincident with the peripheral boundary of the seating surface such that the outline groove establishes an outline contiguous with the area of the seating surface;

removing the guide from the bone subsequent to translating the cutting device along the length of the guide slot; and

removing portions of the bone lying within the area contiguous with and delineated by the outline groove to establish the seating surface.

23. The method of claim 22 including the step of varying the depth of the outline groove along the length of the outline groove to provide different groove depths at different locations along the length of the outline groove, in accordance with the contour of the seating surface.

24. The method of claim 23 for use where the natural joint is a knee joint, the prosthetic device is a prosthetic knee joint, the component part is a unicondylar femoral component, the bone at the site includes a trochlear groove and a femoral condyle, the method including an improvement wherein the step of varying the depth of the outline groove includes varying the depth of the outline groove from a greater depth nearer to the trochlear groove to a lesser depth further from the trochlear groove.