US20080015602A1 - Cutting block for bone resection - Google Patents

Abstract

A cutting block having a base, and a top connected to the base via four walls is disclosed. Each wall has an outwardly facing surface to guide a cutting tool. Each wall also has an attachment hole where a tracker may be attached. The cutting block is floated on the bone using the navigation system to position it at correct locations for the bone resection. After correctly locating the cutting block for each required cut, cutting block is fixed to the bone using pins and the bone resected. Same cutting block is suitable for resection of bone for installation of any size prosthetic device. For certain resections, the rotation angle may be mechanically set and need not be navigated.

Description

BACKGROUND OF THE INVENTION
• This invention relates to method and apparatus for resecting a bone. In particular this invention relates to a method and apparatus for performing all of the bone resections required for implanting a prosthesis using one bone resection instrument such as a cutting block. More particularly, this invention relates to a navigated cutting block that can be “floated” around the bone to be resected to set up the planes for resection.
• There are several types of prostheses known in the art. One type is sometimes referred to as a “resurfacing type”. In these prostheses, the articular surfaces of the bones are “resurfaced” with articular bearing components. One important aspect of these procedures is the correct resection of the bones. These resections must provide planes which are correctly angled in order to properly accept the prosthetic components.
• Recently, various computerized navigation systems have been introduced to aid the practitioner during different surgical procedures. These systems include multiple video cameras which are deployed above the surgical site and a plurality of dynamic reference frame (DRF) devices, also known as trackers, which are attached to body parts and surgical instruments. The trackers can be LED devices or reflective spheres which are visible to the cameras. These trackers are attached to body parts and the surgical instruments and preferably include light emitting devices, such as light emitting diodes which are visible to the video cameras. The trackers communicate position information to a camera system located in the operating room. The camera system is connected to a computer which tracks the location of the tracker and the patient and displays the relationship on a CRT. Using software designed for a particular surgical procedure, a computer receiving input from the cameras guides the placement of surgical instruments such as cutting blocks for bone resection.
• The prior art cutting blocks have several shortcomings. In case of a total knee arthroplasty that involves the replacement of portions of the patella, femur and tibia with artificial components, separate distal resection block and a block for making remaining resections on the femur are required. Also, different size resection blocks are required for different size implants. This increases the inventory of parts in the operating room. Additionally the prior art cutting blocks are sized in proportion to the size of the implant and are not very suitable for minimally invasive surgery. Therefore, there is a need for a navigable cutting block that is small in size, suitable for use with all sizes of implants and allows for all the necessary resections using a single cutting block.
• As used herein, when referring to bones or other parts of the body, the term “proximal” means closer to the heart and the term “distal” means more distant from the heart. The term “inferior” means toward the feet and the term “superior” means towards the head. The term “anterior” means towards the front part of the body or the face and the term “posterior” means towards the back of the body. The term “medial” means toward the midline of the body and the term “lateral” means away from the midline of the body.
SUMMARY OF THE INVENTION
• Cutting blocks of the present invention overcome the shortcomings of the prior art and provide a single cutting block that can make all the resections on a bone (e.g., a femur), is small in size and is suitable for use with all sizes of the implants.
• A first embodiment of the cutting block of the present invention has a base, and a top connected to the base via four walls. Each wall (i.e., the cutting guide) has an outwardly facing surface to guide a cutting tool. Each wall also has an attachment hole where a tracker may be attached. The cutting block is floated, on the bone, free hand by the surgeon using the navigation system to position it at correct locations for the bone resection. After correctly locating the cutting block for each required cut, the cutting block is fixed to the bone using pins and the bone resected.
• A second embodiment of the cutting block has a base, and a top connected to the base via four walls. Three of the four walls have outwardly facing surfaces that are used to guide a cutting tool. Each one of these outwardly facing surface has an attachment hole where a tracker may be attached. The cutting block is floated free hand by the surgeon on the bone using the navigation system to position it at correct locations for the bone resection. After correctly locating the cutting block for each required cut, the cutting block is fixed to the bone by inserting pins through the holes in the cutting block and in the bone. Next, the bone is resected. In this embodiment only three outwardly facing surfaces are used to guide a cutting tool, however, the surfaces may be used to guide the cutting tool in making more than one cuts on the bone.
• In yet another embodiment, the cutting block has two pairs of slots in addition to features of the second embodiment. Once the block is first attached to the distal end of the femur, the pins that attached the block to the distal end are left in place and the block relocated to make additional cuts on the bone by sliding the pins in one of the two pairs of slots. Since the block is now partially located by the pins, the rotation of the remaining resection is mechanically set and need not be navigated. The second set of slots is similarly used to make other resections.
• In use the cutting blocks described above are floated on the anterior surface of the bone to be resected, fixed in the correct location and one of the outwardly facing surfaces used to make the distal cut on the bone. Thereafter, the cutting block is floated on the resected distal end of the bone and fixed in the correct location for making another cut. The process is repeated to as many times as necessary. In one embodiment the cutting blocks rotational position is mechanically set as described previously.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is an isometric view of a cutting block.
• FIG. 2 is an isometric view of the cutting block ofFIG. 1 from a different angle.
• FIG. 3 is a plan view of the cutting block ofFIG. 1.
• FIGS. 4,5 and6 are side views from different sides of the cutting block ofFIG. 1.
• FIG. 7 is another plan view showing the base of the cutting block ofFIG. 1.
• FIG. 8 is an isometric view of another embodiment of a cutting block.
• FIG. 9 is an isometric view of the cutting block ofFIG. 8 from a different angle.
• FIG. 10 is a plan view of the cutting block ofFIG. 8.
• FIGS. 11,12 and13 are side views from different sides of the cutting block ofFIG. 8.
• FIG. 14 is another plan view showing the base of the cutting block ofFIG. 8.
• FIG. 15 is an isometric view of another embodiment of a cutting block.
• FIG. 16 is an isometric view of the cutting block ofFIG. 14 from a different angle.
• FIG. 17 is a plan view of the cutting block ofFIG. 14.
• FIGS. 18,19 and20 are side views from different sides of the cutting block ofFIG. 14.
• FIG. 21 is another plan view showing the base of the cutting block ofFIG. 14.
• FIG. 22A shows cutting block and tracker placed on a femur for making a distal cut.
• FIG. 22B shows cutting block and tracker placed on a femur for making an anterior cut.
• FIG. 22C shows cutting block and tracker placed on a femur for making a posterior cut.
• FIG. 22D shows cutting block and tracker placed on a femur for making an anterior chamfer cut.
• FIG. 22E shows cutting block and tracker placed on a femur for making a posterior chamfer cut.
DETAILED DESCRIPTION
• FIGS. 1-7 show a first embodiment of a cuttingblock20. Cuttingblock20 has abase22 and a top24.Base22 is connected to top24 via fourwalls26,28,30 and32.Wall28 runs frombase22 to top24 and has an outwardly facingsurface29 to guide a cutting tool.Surface29 ofwall28 may be angled to match an angle on prosthesis such as a femoral prosthesis. The angle may be, for example, seven degrees with respect tobase22. The outwardly facingsurface29 may be used to make, for example, an anterior cut on a femur.Wall26 runs frombase22 to top24 and has an outwardly facingsurface27 to guide a cutting tool. Outwardly facingsurface27 ofwall26 may be used, for example, to make distal and posterior cuts on a femur.Wall30 runs frombase22 to top24 and has yet another outwardly facingsurface31 that may guide a cutting tool.Wall30 may be angled with respect tobase22. The angle that wall30 forms withbase22 may be determined based upon the angle at which certain cut, for example, a chamfer cut on a femur is to be made.Wall32 runs frombase22 to top24 and has yet another outwardly facingsurface33 that may guide a cutting tool.Wall32 may also be angled with respect tobase22. The angle that wall32 forms withbase22 may also be determined based upon the angle that a certain cut, for example, a chamfer cut on a femur is to be made. The angles made bywalls30 and32 withbase22 may be same or may differ from each other. Cuttingblock20 may be formed, for example, from a solid or hollow piece of metal, plastic or other suitable material and provide the outwardly facing surfaces described above and other features that will be described hereafter.
• Walls26,28,30,32 have attachment holes34,36,38 and40 respectively. A tracker may be attached to any one of the attachment holes34,36,38 and40, for navigating cuttingblock20 for proper positioning on the corresponding surface on the bone.Holes34,36,38 and40 each havesmall openings42 and44 seen inFIGS. 1 and 3.Openings42 and44 accommodate spring loaded ball like structures on the tracker attached in any one of theholes34,36,38 and40, thereby aiding in attachment of tracker to cuttingblock20.Top24 has fourholes46,48,50 and52. A pin may be driven through one or more ofholes46,48,50 and52 to attach cuttingblock20 to a bone.Top24 may have more or less than four holes.
• FIGS. 8-14 show a cuttingblock54 that is a second embodiment of the invention. If the chamfer cuts on a bone are to be at same angle, cuttingblock20 can be made smaller. Cuttingblock54 is an example of such smaller block that is more suitable for minimally invasive surgery. Cuttingblock54 has abase56 and a top58.Walls60,62,64 and66 run frombase56 totop58.Wall62 has an outwardly facingsurface63 which may guide a cutting tool.Wall62 may be angled, for example, seven degrees with respect to the base, to match the angle on the prosthesis to be used.Wall64 has an outwardly facingsurface65 to guide a cutting tool.Wall64 is angled with respect to the base. The angle is determined based upon the angle that a certain cut, for example, a chamfer cut on a femur is to be made. Outwardly facingsurface65 may also be used to make another cut, for example, a second chamfer cut that is at the same angle as the first chamfer cut.Wall60 has an outwardly facingsurface61 to guide a cutting tool. Outwardly facingsurface61 may be used, for example, to make distal and posterior cuts on a femur.
• Walls60,62 and64 have attachment holes68,70 and72 respectively. A tracker may be attached to any one of the attachment holes68,70 and72. Attachment means of another shape or design, for example, an opening of non-circular shape or a projection or a mechanical detail of suitable geometry and construction may also be used for attaching a tracker.Holes68,70 and72 each havesmall openings74,76 as seen inFIGS. 8 and 10.Openings74 and76 accommodate spring loaded ball like structures on the tracker attached inholes68,70, and72, thereby aiding in attachment of the tracker to cuttingblock54.Top58 of cuttingblock54 has twoholes75 and77.Top58 may have more or less holes. A pin may be driven through one ormore holes75 and77 to attach cuttingblock54 to a bone.
• FIGS. 15-21 show yet another embodiment of the present invention—cuttingblock78. Cuttingblock78 has abase80 and a top82.Walls84,86 and88 extend frombase80 totop82.Wall84 has an outwardly facingsurface85 that can guide a cutting tool. The outwardly facingsurface85 may be used, for example, to make the distal and the posterior cut on a femur.Wall86 has an outwardly facingsurface87 that can guide a cutting tool for making, for example, an anterior cut on a femur. The outwardly facingsurface87 ofwall86 may be at an angle, for example, seven degrees with respect tobase80. This angle may match the corresponding angle on the prosthesis to be used.Wall88 has an outwardly facingsurface89 that can guide cutting tools for making, for example, chamfer cuts on a femur. The outwardly facingsurface89 forms an angle withbase80. This angle may correspond with the angle of the chamfer cut on a femur.
• Walls84,86 and88 have attachment holes90,92 and94. Eachattachment hole90,92, or94 hassmall openings96 and98. The attachment of atracker112 to cuttingblock78 is similar to the attachment of tracker to cuttingblock54 and was described in detail previously in context of cuttingblock54. Cuttingblock78 has twoholes100 and102. A pin114 may be driven through one or both ofholes100 and102 to attach cuttingblock78 to a bone. Cuttingblock78 has twoparallel slots104 and106 that run in directions generally orthogonal to the outwardly facingsurface87. Cuttingblock78 has a second pair ofparallel slots108 and110 that run in direction generally orthogonal toslots104 and106.
• FIGS. 22A-22Eshow cutting block78 withtracker112 attached to it via attachment holes90,92 or94.Tracker112 is used to position cuttingblock78 on different surfaces of a femur for making various cuts. However,tracker112 can be attached to cuttingblock78 via alternate means. The alternate methods may not permit obtaining accurate positional information on all 6 degrees-of-freedom, but there may be times during a surgical procedure where 6 degree-of-freedom positional information is not required. Some instruments have recesses intended for a purpose other than attachment of a tracker; however, these recesses can also be used to locate a tracker. For example, a slotted cutting block with a recess intended to guide a saw blade can be used to locate a tracker relative to the cutting block through the use of an adaptor that has both a feature approximately the same thickness as the saw blade and that can fit in the recess and a feature that can be utilized to attach the tracker to the adaptor. Some instruments have surfaces intended for a purpose other than tracker attachment; however, these surfaces can also be used to locate a tracker. For example, an open-face cutting block, such as cuttingblock78, with a surface intended to guide a saw blade can be used to locate a tracker, such astracker112, relative to the cutting block through the use of an adaptor (not shown) that has both a feature that can be placed in direct apposition to the surface and a feature that can be utilized to attach the tracker to the adaptor.
• In use, for example, in a surgery to implant a tricompartmental (i.e., a component for replacing the medial and lateral condyler and the patellar groove on either the left or right femur) femoral component on the distal femur, cuttingblock20,54 or78 is located on the anterior surface of a femur using navigation. To this end, the tracker pins are inserted into the bone and anatomical landmarks digitized.Tracker112 is attached to hole34,68 or90 andblock20,54 or78 is floated (i.e., placed free hand) onto the femur in correct orientation. In this position the outwardly facingsurface27,61 or85 is in correct position to resect the distal condyler surface of the femur. At thistime block20,54 or78 is pinned down on the femur by driving pins through a pair of holes on top24,58 or82 respectively.Holes46,52 (or48,50) may be used when cuttingblock20 is being used.Holes75 and77 are used when cuttingblock54 is employed. And, incase cutting block78 is being used, pins may be driven throughholes100 and102. Once cuttingblock20,54 or82 is pinned into place, the distal condyle is resected using outwardly facingsurfaces27,61 or85 respectively.
• After distal resection, cuttingblock20 is rotated and placed on the distal resected end of the femur so thatbase22 rests on the resected distal surface. Cuttingblock20 is placed free hand onto the femur in correct orientation. In this orientation the anterior cutting surface (i.e., the outwardly facing surface29) is in the appropriate anterior-posterior location and the internal/external rotation of the block matches that of the transepicondylar axis, anterior-posterior axis or the orientation the surgeon sets using the navigation system. Now cuttingblock20 is pinned into place by driving pins through at least two of four theholes46,48,50 and52. Next anterior resection is performed using the outwardly facingsurface29 as a guide for a cutting tool. Next, cuttingblock20 is removed from the bone and tracker attached inhole34. Cuttingblock20 is placed in the correct orientation for the posterior cut, pinned to the distal end as previously described, tracker removed, and posterior cut made using the outwardly facingsurface27 as a guide for the cutting tool. Next, cuttingblock20 is removed from bone, a tracker attached to hole40, cuttingblock20 is placed in the correct orientation for a chamfer cut and pinned to the bone as previously described, tracker removed and a chamfer cut made using outwardly facingsurface33. A second chamfer cut may be made in a manner similar to the first chamfer cut described above. For second chamfer cut the surgeon may be able to choose between outwardly lyingsurface31 or33 if the prosthesis has two identical chamfer angles. If the prosthesis has differing chamfer angles, one cut may be made using each one ofsurfaces31 and33.
• When cuttingblock78 is used, the procedure for making the distal cut and the anterior cut is same as described in the context of cuttingblock20. In case of cuttingblock78holes100 and102 are used to pin the block to the bone for making the distal and the anterior cuts using outwardly facingsurfaces85 and87 respectively. Thereafter, the block is removed from the bone but the pins116 and118 are left in place for the anterior resection. Since pins116 and118 are used to position cuttingblock78 for the remaining resection, the rotation of the remaining resections is mechanically set and need not be navigated. Next, pins116 and118 are inserted inslots104 and106 and the cuttingblock78 is slid along the pins to correct location for making the posterior cut. A tracker may be attached to hole90 to navigate the block for posterior cut. Once correctly located, cuttingblock78 is pinned in place by driving at least one pin114 through one of theholes100 and102. Now the posterior resection is performed using the outwardly facingsurface87 as a guide for the cutting tool.
• Next, cuttingblock78 is removed, leaving pins116 and118 that were engaged inslots104 and106 in place. Cuttingblock78 is rotated and pins116 and118 that were left in the place are inserted inslots108 and110. Cuttingblock78 is slid along pins116 and118 to correct location for making a chamfer cut. A tracker may be attached to hole94 to navigate the block for chamfer cut. Once correctly located, cuttingblock78 is pinned in place by driving at least one pin114 thoughholes100 and102. Now the anterior or posterior chamfer cut is made. Next, the process is repeated with the block rotated by 180 degrees to make the second chamfer cut.
• When cuttingblock54 is used, the procedure for making the distal cut and the anterior cut is same as described in the context of cuttingblock20. In case of cuttingblock54, holes75 and77 are used to pinblock54 to the bone. The distal and anterior cuts are made using the outwardly facingsurfaces61 and63 respectively. Thereafter, the cuttingblock78 is removed from the distal surface, the tracker attached to hole68, the cuttingblock78 floated into correct orientation and position for making the posterior cut, pinned in place by driving pins throughholes75 and77 and the posterior cut made using the outwardly facingsurface61.
• Next, cuttingblock54 is removed from the bone, a tracker attached to hole72 and cuttingblock54 floated in correct orientation and position for making a chamfer cut. Cuttingblock54 is pinned to the bone as described previously and the chamfer cut is made using the outwardly facingsurface65. Next the cuttingblock54 is removed from the bone, tracker reattached to hole72 and the process repeated with cuttingblock54 rotated 180 degrees. Cuttingblock54 is floated in correct orientation and position for making a second chamfer cut, it is pinned to the bone and chamfer cut is made using the outwardly facingsurface65.
• Cuttingblock20,54 or78 may also be used, for example, for resection of tibia and talus to install ankle prosthesis. The ankle may be approached from the lateral side, the fibula moved to allow access to the ankle joint and the prosthesis installed after bone resection. Cuttingblock20,54, or78 may floated on the talus and three cuts—a distal cut and two chamfer cuts can be made. In contrast to the traditional cutting block that require different sizes, thesame cutting block20,54 or78 can be used for any size bone (such as a talus or a femur) since the cutting surfaces are referenced to each other in terms of angular relationship but not linear relationship which is set by the navigation system.
• 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 defined by the appended claims.

Claims (50)

1. A cutting block for bone resection, comprising:

a base;

a top;

a first outwardly facing surface extending between the base and the top, the first outwardly facing surface providing a first guiding surface for the resection of anterior surface of the femur;

a second outwardly facing surface extending between the base and the top, the second outwardly facing surface providing a second guiding surface for the resection of the posterior and the distal surface of the femur;

a third outwardly facing surface extending between the base and the top, the third outwardly facing surface providing a third guiding surface for making the anterior chamfer cut on the femur; and

a fourth outwardly facing surface extending between the base and the top, the fourth outwardly facing surface providing a fourth guiding surface for making the posterior chamfer cut on the femur.

2. The cutting block ofclaim 1, further comprising:

at least two holes extending from the top to the base.

3. The cutting block ofclaim 2, further comprising:

a first slot and a second slot, the first and the second slot extending through the thickness of the cutting block and being parallel to each other; and

a third slot and a fourth slot, the third and the fourth slot extending through the thickness of the block and being parallel to each other and orthogonal to the first and the second slot.

4. The cutting block ofclaim 2, further comprising:

at least one mounting means for mounting a tracker.

5. The cutting block ofclaim 4, wherein the mounting means is an opening on one of the first, second, third or fourth outwardly facing surface.

6. The cutting block ofclaim 5, further comprising:

a tracker mounted in the mounting means.

7. The cutting block ofclaim 5, wherein the first outwardly facing surface extending between the base and the top is angled with respect to the base.

8. The cutting block ofclaim 7, wherein the angle matches an angle on a prosthetic device.

9. The cutting block ofclaim 8, wherein the bone being resected is a femur.

10. A cutting block for bone resection, comprising:

a base;

a top; and

four outwardly facing surfaces connecting the base and the top, each of the four outwardly facing surfaces providing at least one guiding surface for making at least one bone resection; wherein one size cutting block can be used for femoral resection suitable for any size femoral prosthesis.

11. The cutting block ofclaim 10, further comprising:

at least two holes extending from the top to the base.

12. The cutting block ofclaim 11, further comprising:

a first slot and a second slot, the first and the second slot extending through the thickness of the cutting block and being parallel to each other; and

a third slot and a fourth slot, the third and the fourth slot extending through the thickness of the block and being parallel to each other and orthogonal to the first and the second slot.

13. The cutting block ofclaim 11, further comprising:

at least one mounting means for mounting a tracker.

14. The cutting block ofclaim 13, wherein the mounting means is an opening on one of the four outwardly facing surfaces.

15. The cutting block ofclaim 14, further comprising:

a tracker mounted in the mounting means.

16. The cutting block ofclaim 14, wherein one of the four outwardly facing surfaces extending between the base and the top is angled with respect to the base.

17. The cutting block ofclaim 16, wherein the angle matches an angle on a prosthetic device.

18. The cutting block ofclaim 17, wherein the bone being resected is a femur.

19. A cutting block for femoral resection, comprising:

a base;

a top; and

four outwardly facing surfaces connecting the base and the top, each of the four outwardly facing surfaces providing at least one guiding surface for making at least one of the anterior, posterior, distal, anterior chamfer and posterior chamfer cuts; wherein the outwardly facing surface providing the guiding surface for the anterior cut is angled with respect to the base, the angle matching the anterior flange angle of a femoral prosthesis.

20. The cutting block ofclaim 19, further comprising:

at least two holes extending from the top to the base.

21. The cutting block ofclaim 20, further comprising:

a first slot and a second slot, the first and the second slot extending through the thickness of the cutting block and being parallel to each other; and

a third slot and a fourth slot, the third and the fourth slot extending through the thickness of the block and being parallel to each other and orthogonal to the first and the second slot.

22. The cutting block ofclaim 20, further comprising:

at least one mounting means for mounting a tracker.

23. The cutting block ofclaim 22, wherein the mounting means is an opening on one of the four outwardly facing surfaces.

24. The cutting block ofclaim 23, further comprising:

a tracker mounted in the mounting means.

25. A cutting block for femoral resection, comprising:

a base;

a top;

a first outwardly facing surface extending between the base and the top, the first outwardly facing surface providing a first guiding surface for the resection of anterior surface of the femur;

a second outwardly facing surface extending between the base and the top, the second outwardly facing surface providing a second guiding surface for the resection of the posterior and the distal surface of the femur;

a third outwardly facing surface extending between the base and the top, the third outwardly facing surface providing a third guiding surface for making the anterior chamfer cut on the femur; and

a fourth outwardly facing surface extending between the base and the top, the fourth outwardly facing surface providing a fourth guiding surface for making the posterior chamfer cut on the femur; wherein the first outwardly facing surface is angled with respect to the base.

26. The cutting block ofclaim 25, further comprising:

at least two holes extending from the top to the base.

27. The cutting block ofclaim 26, further comprising:

a first slot and a second slot, the first and the second slot extending through the thickness of the cutting block and being parallel to each other; and

a third slot and a fourth slot, the third and the fourth slot extending through the thickness of the block and being parallel to each other and orthogonal to the first and the second slot.

28. The cutting block ofclaim 26, further comprising:

at least one mounting means for mounting a tracker.

29. The cutting block ofclaim 28, wherein the mounting means is an opening on one of the four outwardly facing surfaces.

30. The cutting block ofclaim 29, further comprising:

a tracker mounted in the mounting means.

31. The cutting block ofclaim 30, wherein the angle formed by the first outwardly facing surface with respect to the base matches an angle on a prosthetic device.

32. A cutting block for femoral resection, comprising:

a base;

a top;

a first outwardly facing surface extending between the base and the top, the first outwardly facing surface providing a first guiding surface for the resection of anterior surface of the femur;

a second outwardly facing surface extending between the base and the top, the second outwardly facing surface providing a second guiding surface for the resection of the posterior and the distal surface of the femur; and

a third outwardly facing surface extending between the base and the top, the third outwardly facing surface providing a third guiding surface for making the anterior chamfer cut and the posterior chamfer cut on the femur; wherein one size cutting block can be used for femoral resection suitable for any size femoral prosthesis.

33. The cutting block ofclaim 32, further comprising:

at least two holes extending from the top to the base.

34. The cutting block ofclaim 33, further comprising:

a first slot and a second slot, the first and the second slot extending through the thickness of the cutting block and being parallel to each other; and

a third slot and a fourth slot, the third and the fourth slot extending through the thickness of the block and being parallel to each other and orthogonal to the first and the second slot.

35. The cutting block ofclaim 33, further comprising:

at least one mounting means for mounting a tracker.

36. The cutting block ofclaim 35, wherein the mounting means is an opening on one of the first, second or third outwardly facing surface.

37. The cutting block ofclaim 36, further comprising:

a tracker mounted in the mounting means.

38. The cutting block ofclaim 36, wherein the first outwardly facing surface extending between the base and the top is angled with respect to the base.

39. The cutting block ofclaim 38, wherein the angle matches an angle on a prosthetic device.

40. A cutting block for femoral resection, comprising:

a base;

a top;

a first outwardly facing surface extending between the base and the top, the first outwardly facing surface providing a first guiding surface for the resection of anterior surface of the femur;

an angle formed between the first outwardly facing surface and the base, the angle matching the anterior flange angle of a femoral prosthesis to be implanted;

a second outwardly facing surface extending between the base and the top, the second outwardly facing surface providing a second guiding surface for the resection of the posterior and the distal surface of the femur;

a third outwardly facing surface extending between the base and the top, the third outwardly facing surface providing a third guiding surface for making the anterior chamfer cut on the femur; and

a fourth outwardly facing surface extending between the base and the top, the fourth outwardly facing surface providing a fourth guiding surface for making the posterior chamfer cut on the femur; wherein one size cutting block can be used for femoral resection suitable for any size femoral prosthesis.

41. The cutting block ofclaim 40, further comprising:

at least two holes extending from the top to the base.

42. The cutting block ofclaim 41, further comprising:

a first slot and a second slot, the first and the second slot extending through the thickness of the cutting block and being parallel to each other; and

a third slot and a fourth slot, the third and the fourth slot extending through the thickness of the block and being parallel to each other and orthogonal to the first and the second slot.

43. The cutting block ofclaim 41, further comprising:

at least one mounting means for mounting a tracker.

44. The cutting block ofclaim 43, wherein the mounting means is an opening on one of the first, second, third or fourth outwardly facing surface.

45. The cutting block ofclaim 44, further comprising:

a tracker mounted in the mounting means.

46. A method of resecting a femur, the method comprising the steps of:

locating a cutting block on the anterior surface of the femur using a navigation system;

making a distal cut on the femur using a surface of the cutting block to guide the cutting instrument, the cutting block being located on the anterior surface of the femur, and the cut resulting in a planer distal surface;

locating the cutting block in a first location on the planer distal surface using the navigation system;

anchoring the cutting block on the planer distal surface using pins;

re-locating the cutting block in a second, third and fourth position on the planer distal surface using the navigation system;

making an anterior cut, a posterior cut, an anterior chamfer cut and a posterior chamfer cut using a surface of the cutting block as a guide, the cutting block being anchored in the first, second, third and fourth position respectively during the making of the anterior cut, the posterior cut, the anterior chamfer cut and the posterior chamfer cut.

47. The method ofclaim 46, further comprising the steps of:

using the pins installed for anchoring in the first position to mechanically fix the rotation of the relocated cutting block in the second, third, and fourth position.

48. A method of resecting a femur, the method comprising the steps of:

providing a cutting block adapted to resecting the femur for installation of any size prosthetic device, the cutting block having an angled surface, the angle of the angled surface matching an angle on the prosthetic device;

locating a cutting block on the anterior surface of the femur using a navigation system;

making a distal cut on the femur using a surface of the cutting block to guide the cutting instrument, the cutting block being located on the anterior surface of the femur, and the cut resulting in a planer distal surface;

locating the cutting block in a first location on the planer distal surface using the navigation system;

anchoring the cutting block on the planer distal surface using pins;

re-locating the cutting block in a second, third and fourth position on the planer distal surface using the navigation system;

making an anterior cut, a posterior cut, an anterior chamfer cut and a posterior chamfer cut using a surface of the cutting block as a guide, the cutting block being anchored in the first, second, third and fourth position respectively during the making of the anterior cut, the posterior cut, the anterior chamfer cut and the posterior chamfer cut.

49. The method ofclaim 48, further comprising the steps of:

using the pins installed for anchoring in the first position to mechanically fix the rotation of the relocated cutting block in the second, third, and fourth position.

50. A method of resecting bone, the method comprising the steps of:

providing a cutting block adapted to resecting the bone for installation of any size prosthetic device;

locating a cutting block on the bone using a navigation system;

making a cut on the bone using a surface of the cutting block to guide the cutting instrument;

locating the cutting block in a first location on the resected surface using the navigation system;

anchoring the cutting block on the resected surface using pins;

using the pins installed for anchoring in the first position to mechanically fix the rotation of the relocated cutting block in subsequent positions for resecting the bone.

Images