Abstract:
One aspect of the present invention relates to a tissue resection guide that includes a central body, a first flange and a second flange, the flanges having first and second guide surfaces, respectively, suitable for use in tissue resection. Each guide surface lies on a cutting plane, both planes intersecting interior to the flanges. In the embodiments described, the availability of two cutting planes ensures resections in more than one plane are possible. As a result, bone segments can be removed via a cut on two planes without the need to cut across an entire section of bone on one plane. In some embodiments, an opening exists between the first flange and the second flange to ensure that each resection overlaps. In other aspects of the invention, systems and methods of use for the tissue resection guide are described.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is a continuation of U.S. patent application Ser. No. 13/001,080, filed on Feb. 10, 2012, which application is a U.S. National Phase entry under 35 U.S.C. §371 of International Application No. PCT/US2009/048699, filed Jun. 25, 2009 which claims priority to U.S. Provisional Application No. 61/133,186, filed Jun. 25, 2008, and U.S. Provisional Application No. 61/178,343, filed May 14, 2009, all of which are hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to surgical instrumentation and methods for such procedures such as, for example, a total joint replacement within a patient. 
         [0003]    Various endoprosthetic devices are known for repairing or replacing joints in a patient. Specifically, it is known to use an endoprosthesis to replace a damaged ankle joint. The ankle joint is a comparatively small joint relative to the weight bearing and torque the joint must withstand. These factors have made the design of total ankle joint replacements technically challenging. Total ankle replacement has been investigated since the 1970&#39;s with initially promising results, but the procedure was essentially abandoned in the 1980&#39;s due to a high long-term failure rate, both in terms of pain control and improved function. However, researchers have continued to investigate new designs, which can be broadly subdivided into constrained and unconstrained designs. Constrained designs offer the advantage of greater stability, but with decreased mobility and increased stress at the bone implant interface, potentially leading to a greater risk of early loosening and failure. Unconstrained designs provide improved range of motion in multiple planes, but at the expense of stability. Early devices investigated were implanted with cement fixation, which in recent years has given way to cementless designs. One such cementless, non-constrained mobile bearing device that has proven to be successful is a total ankle replacement. An example of the total ankle replacement, shown in  FIGS. 1 and 2 , is further described in U.S. Pat. No. 6,852,130 and is commercially known as the S.T.A.R.® or the Scandinavian Total Ankle Replacement System. 
         [0004]    Total joint replacements, such as the S.T.A.R.®, have been implanted to repair damaged joints using a combination of cut guides and free hand cutting and shaping to sufficiently prepare the bone contacting the total joint replacement. 
         [0005]    It would be desirable to reduce the amount of measuring, free hand cutting and/or re-mounting of cut guides to the remaining healthy bone structure to efficiently and accurately prepare the resected tissue surface receiving the total joint replacement with repeatable results and minimum bone removal. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The present invention relates to an apparatus, system and method for tissue resection. In one aspect, the apparatus is a tissue resection guide. In a first embodiment, the tissue resection guide includes a central body portion, a first flange, a second flange, a cutting slot and a cutting surface. The central body portion includes a first end, second end and also a bottom surface. The bottom surface of the central body portion defines a first guide surface. The first flange extends from the central body portion and defines a second guide surface. The first and the second guide surfaces are parallel. The second flange also extends from the central body portion and defines a third guide surface. The cutting slot is defined by an opening between the central body portion and the first flange and has a length that extends from a first location proximal to the first end to a second location proximal to the second end. The shape of the cutting slot is such that a first cutting plane runs therethrough. The cutting surface is defined by the third guide surface. The cutting surface is also a second cutting plane. The first and second cutting planes intersect proximal to the second location. 
         [0007]    In another embodiment, an opening can exist between the first flange and the second flange such that there is no direct contact between the first and second flanges. In yet another embodiment, the third guide surface of the second flange can be at an obtuse angle relative to the first guide surface. 
         [0008]    In yet another embodiment, the first location of the cutting slot can include a first aperture and the second location of the cutting slot can include a second aperture. Both of the apertures are adapted to receive pins. In a variant, the first aperture can be defined by a curved portion of the second guide surface proximal to the first location. Similarly, the second aperture can be defined by a curved portion of the second guide surface at the second location and a curved portion of the third guide surface proximal to the second end of the central body portion. In other variants, the first aperture and second aperture can be further defined. The first aperture can be defined by a concave shaped portion of the second guide surface at the first location. The second aperture can be defined in part by a notch on the second guide surface at the second location with the remaining part defined by a concave shaped portion of the third guide surface proximal to the second end of the central body portion. 
         [0009]    In another embodiment, the first flange can include a length having a first portion and a second portion. The first portion can extend from the central body portion in a direction substantially perpendicular to the first guide surface and the second portion can extend from an end of the first portion distal to the central body portion to the second location of the cutting slot. The second portion can be substantially parallel to the first guide surface. In a variant, the guide can also include a first and second aperture. The first aperture can be defined by a concave shaped portion of the second guide surface at the first location. The second aperture can be defined by a notch on the second guide surface at the second location along with a concave shaped portion of the third guide surface proximal to the second end of the central body portion. 
         [0010]    In yet another embodiment, the second flange of the tissue resection guide can further comprise two portions. The guide can further include a second cutting slot defined by an opening between the two portions. In still further embodiments, the first cutting plane through the cutting slot can be at an angle between approximately 85 degrees and approximately 95 degrees relative to a longitudinal axis of a bone to be resected. 
         [0011]    In an alternative embodiment to the first embodiment, a tissue resection guide includes a central body portion, a first flange, a second flange, a cutting slot and a cutting surface. The first flange is attached to the central body portion at the first end of the central body portion. The second flange is attached to the central body portion at the second end of the central body portion. Both the first flange and the second flange are attached on a common surface of the central body portion. The cutting slot is defined by an opening between the central body portion and the first flange and has a length that extends from a first location proximal to the first end to a second location proximal to the second end. The cutting slot is shaped such that a first cutting plane runs therethrough. The cutting surface of the guide is defined by a surface of the second flange. The cutting surface is also a second cutting plane. The first and second cutting planes intersect proximal to the second location. 
         [0012]    In another embodiment, the tissue resection guide can include an opening between the first flange and the second flange. The opening is situated so that there is no direct contact between the first flange and the second flange. In other embodiments, the surface of the second flange can be at an obtuse angle relative to the first cutting plane. 
         [0013]    In yet another embodiment, the first location of the cutting slot can include a first aperture and the second location of the cutting slot can include a second aperture. Both the first and second apertures can be adapted to receive pins. In a variant, the first aperture can be defined by a curved portion of an inner surface on the first flange proximal to the first location. Similarly, the second aperture can be defined by a curved portion of the inner surface at the second location and a curved portion of the cutting surface of the second flange proximal to the second end of the central body portion. 
         [0014]    In another embodiment, the first flange can include a length having a first portion and a second portion. The first portion can extend from the central body portion in a direction substantially perpendicular to the first cutting plane and the second portion can extend from an end of the first portion distal to the central body portion to the second location of the cutting slot. In this way, the second portion can be substantially parallel to the first cutting plane. In a variant, the tissue resection guide can include a first and second aperture. The first aperture can be defined by a concave shaped portion of an inner surface on the first flange at the first location. The second aperture can be defined by a notch on the inner surface at the second location and a concave shaped portion of the cutting surface of the second flange proximal to the second end of the central body portion. 
         [0015]    In other embodiments, the second flange can further comprise two portions wherein a second cutting slot is defined by an opening between the two portions. In still further embodiments, the first cutting plane through the cutting slot can be at an angle between approximately 85 degrees and approximately 95 degrees relative to a longitudinal axis of a bone to be resected. 
         [0016]    In yet another alternative to the first embodiment, a tissue resection guide includes a central body portion, a first flange, a second flange, a cutting slot and a cutting surface. The central body portion includes a first end and a second end. The first flange extends from the central body portion at the first end of the central portion. The second flange extends from the central body portion at the second end of the central body portion. Both the first flange and the second flange extend from a common inferior surface of the central portion. The cutting slot is defined by an opening between the inferior surface of the central portion and a superior surface of the first flange and has a length that extends from a first location proximal to the first end to a second location proximal to the second end. The cutting slot is shaped such that a first cutting plane runs therethrough. The cutting surface is defined by a lateral surface of the second flange, and also forms a second cutting plane. The cutting planes are positioned so that the first cutting plane intersects the second cutting plane proximal to the second location. 
         [0017]    In another aspect, the present invention relates to a system for resecting tissue. The system includes an alignment guide; an attachment block; a first positioning block; a second positioning block; a tissue resection guide; a first flange; a second flange; a cutting slot; and a cutting surface. The attachment block is attached to the alignment guide. The first positioning block is attached to the attachment block through a first rack. The second positioning block is attached to the first positioning block. The tissue resection guide is attached to the second positioning block and includes a central body portion having a first end and a second end. The first flange extends from the central body portion at the first end of the central body portion and the second flange extends from the central body portion at the second end of the central portion. The first flange and the second flange both extend from a bottom surface of the central body portion. The cutting slot is defined by an opening between the bottom surface of the central body portion and the first flange and has a length that extends from a first location proximal to the first end to a second location proximal to the second end. The cutting slot further includes a shape such that a first cutting plane runs therethrough. The cutting surface is defined by a surface of the second flange and is also a second cutting plane. The first cutting plane and the second cutting plane are oriented such that the first cutting plane intersects the second cutting plane proximal to the second location. 
         [0018]    In another embodiment, the tissue resection guide can include a fastener attached to an aperture in the second positioning block. 
         [0019]    In yet another embodiment, the first location and the second location of the cutting slot can each be defined by an aperture for receiving pins. In a variant, the system can also include pins for placement in the apertures such that bone adjacent to a bone identified for resection is protected from resection. In another variant, the system can include a spacer guide in addition to pins. The spacer guide can be placed within the first flange of the tissue resection guide. In other variants, the second flange can further include two portions wherein a second cutting slot is defined by an opening between the two portions. In yet another variant, the first cutting plane through the cutting slot can be at an angle between approximately 85 degrees and approximately 95 degrees relative to a longitudinal axis of the bone. 
         [0020]    In another aspect, the present invention relates to a method of resecting a tibial bone. The method includes the following steps: creating an incision at the location of the bone to be resected; securing an alignment guide to the bone; securing an attachment block to the alignment guide and the bone, wherein the attachment block is further attached to a first positioning block that includes apertures and a second positioning block; securing a tissue resection guide into the second positioning block, wherein the tissue resection guide comprises a central body portion, a first flange extending from the central body portion and a second flange extending from the central body portion, wherein a cutting slot is defined by an opening between the central body portion and the first flange and a cutting surface is defined by a surface on the second flange; positioning the tissue resection guide by using the second positioning block and by aligning the first flange of the tissue resection guide between the medial and lateral malleolus; inserting pins into the apertures of the first positioning block; inserting pins into a first aperture and a second aperture of the tissue resection guide, the first aperture located at a first end of the cutting slot and the second aperture located at the second end of the cutting slot adjacent to the cutting surface, thereby protecting the medial and lateral malleolus from resection; inserting a tissue resection tool into the cutting slot to resect a distal end of the bone along a first cut line; removing the tissue resection tool; and inserting the tissue resection tool onto the cutting surface to resect the bone along a second cut line such that a portion of the bone is removed following the completion of the second cut. 
         [0021]    In another embodiment, the method can further include the step of placing a spacer guide to the tissue resection guide prior to inserting the tissue resection tool into the cutting slot. In yet another embodiment, the method can further include the step of aligning an alignment rod attached to the alignment guide with the tibia so that a first plane running through the cutting slot is angled at approximately 85 degrees to approximately 95 degrees relative to a length of the tibia. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The foregoing summary, as well as the following detailed description of embodiments of the surgical instrumentation and methods of use for implanting a total joint replacement will be better understood when read in conjunction with the appended drawings of exemplary embodiments. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
           [0023]    In the drawings: 
           [0024]      FIG. 1  is a perspective view of a total joint replacement implanted between first and second bones; 
           [0025]      FIG. 2  is a side, partially cross-section, partially transparent side view of the implanted total joint replacement of  FIG. 1 ; 
           [0026]      FIG. 3  is a perspective view of an alignment guide in accordance with an exemplary embodiment of the present invention; 
           [0027]      FIG. 4  is a top view of the alignment guide shown in  FIG. 3  with the positioning tool removed; 
           [0028]      FIG. 5  is a perspective view of a first tissue resection guide in accordance with an exemplary embodiment of the present invention; 
           [0029]      FIG. 6  is a perspective view of a spacer guide in accordance with an exemplary embodiment of the present invention; 
           [0030]      FIG. 7  is a perspective view of a second tissue resection guide in accordance with an exemplary embodiment of the present invention; 
           [0031]      FIG. 8  is a perspective view of the second tissue resection guide shown in  FIG. 7  having a tab extension; 
           [0032]      FIG. 9A  is a perspective view of a datum in accordance with an exemplary embodiment of the present invention; 
           [0033]      FIG. 9B  is a top plan view of the datum shown in  FIG. 9A ; 
           [0034]      FIG. 9C  is a bottom perspective front view of the datum shown in  FIG. 9A . 
           [0035]      FIG. 10A  is a perspective view of a distractor in accordance with an exemplary embodiment of the present invention shown in an insertion position and securing the datum of  FIG. 9A ; 
           [0036]      FIG. 10B  is an enlarged view of a datum lock of the distractor shown in  FIG. 10A ; 
           [0037]      FIG. 10C  an enlarged top view of a paddle of the distractor shown in  FIG. 10A  being pivoted for demonstrative purposes; 
           [0038]      FIG. 10D  a perspective view of the distractor shown in  FIG. 10A  with the upper handle removed, the ratchet pivoted downwardly and the datum shown in phantom; 
           [0039]      FIG. 10E  is a bottom plan view of the distractor shown in  FIG. 10D ; 
           [0040]      FIG. 11A  is a top plan view of a third tissue resection guide in accordance with an exemplary embodiment of the present invention; 
           [0041]      FIG. 11B  is a bottom perspective view of the third tissue resection guide shown in  FIG. 11A ; 
           [0042]      FIG. 12A  is a top plan view of a fourth tissue resection guide in accordance with an exemplary embodiment of the present invention; 
           [0043]      FIG. 12B  is a front elevational view of the fourth tissue resection guide shown in  FIG. 12A ; 
           [0044]      FIG. 12C  is a side elevational view of the fourth tissue resection guide shown in  FIG. 12A ; 
           [0045]      FIG. 13  is a perspective view of a window trial in accordance with an exemplary embodiment of the present invention; 
           [0046]      FIG. 14  is a perspective view of a barrel cut guide in accordance with an exemplary embodiment of the present invention; 
           [0047]      FIG. 15  is a perspective view of a fin cutter in accordance with an exemplary embodiment of the present invention. 
           [0048]      FIG. 16  is a perspective view of an incision in an ankle exposing the ankle joint; 
           [0049]      FIG. 17  a side elevational view of a lower leg of a patient with the alignment guide shown in  FIG. 3  attached to the first bone; 
           [0050]      FIG. 18  is a top plan view of the alignment guide shown in  FIG. 4  attached to the first bone and outlining two resection paths; 
           [0051]      FIG. 19  is a top plan view of the alignment guide shown in  FIG. 18  with the first tissue resection guide of  FIG. 5  attached; 
           [0052]      FIG. 20  is a side view of the alignment guide and first tissue resection guide shown in  FIG. 19  with the spacer guide of  FIG. 6  attached; 
           [0053]      FIG. 21  is a side view of the alignment guide shown if  FIG. 4  with the second tissue resection guide of  FIG. 8  attached to the alignment guide and the second bone; 
           [0054]      FIG. 22  is a side view of a space evaluator positioned between the first and second resected tissue surfaces; 
           [0055]      FIG. 23  is a perspective view of a sizer on top of the second resected tissue surface; 
           [0056]      FIG. 24  is a perspective view of the distractor shown in  FIG. 10A  in the insertion position; 
           [0057]      FIG. 25  is a perspective view of the distractor shown in  FIG. 10A  in the distracted position; 
           [0058]      FIG. 26  is a perspective view of the datum attached to the second resected tissue surface; 
           [0059]      FIG. 27  is a rear perspective view of a second tissue resection tool being guided by the third tissue resection guide shown in  FIG. 11A ; 
           [0060]      FIG. 28  is a side elevational view of a third tissue resection tool being guided by the third tissue resection guide shown in  FIG. 11A ; 
           [0061]      FIG. 29  is a front perspective view of the second tissue resection tool being guided by the third tissue resection guide shown in  FIG. 11A ; 
           [0062]      FIG. 30  is a perspective view of the second resected tissue surface after use of the second and third tissue resection guides shown in  FIGS. 8 and 11A  respectively; 
           [0063]      FIG. 31  is a perspective view of a fourth tissue resection tool being guided by the fourth tissue resection guide shown in  FIG. 12A ; 
           [0064]      FIG. 32  is a perspective view of the fourth tissue resection guide shown in  FIG. 31  showing the resected surface created by the fourth tissue resection tool; 
           [0065]      FIG. 33  is a perspective view of the resected tissue surfaces after use of the second, third and fourth tissue resection guides shown in  FIGS. 8, 11A and 12A  respectively; 
           [0066]      FIG. 34  is a perspective view of the window trial shown in  FIG. 13  on the resected tissue surfaces shown in  FIG. 33 ; and 
           [0067]      FIG. 35  is a side elevational partially transparent view of the barrel cut guide shown in  FIG. 14  and the window trial on the resected tissue surfaces shown in  FIG. 34 . 
       
    
    
     DETAILED DESCRIPTION 
       [0068]    Referring to the drawings in detail, wherein like reference numerals indicate like elements throughout, there is shown in  FIGS. 1-35  surgical instrumentation and methods of use for installing a prosthesis or endoprosthesis such as, for example, a total joint replacement, generally designated  10 , between first and second bones  12 ,  14 , in accordance with exemplary embodiments of the present invention. 
         [0069]    Referring to  FIGS. 1 and 2 , in one embodiment, the total joint replacement  10  may be an ankle joint and the first and second bones  12 ,  14  may be the tibia and the talus respectively. A third bone  16 , such as the fibula, may also contact the total joint replacement  10 . In one embodiment, the total joint replacement  10  is a total ankle replacement such as described in U.S. Pat. No. 6,852,130 which is hereby incorporated by reference in its entirety, and is commercially known as the S.T.A.R.® or the Scandinavian Total Ankle Replacement System. However, the present invention may be used for resecting tissue surfaces in implanting any prosthetic device. 
         [0070]    In one an embodiment, the total joint replacement  10  includes a first endoprosthetic component  18  that engages the first bone  12  and a second endoprosthetic component  20  that engages the second bone  14 . In one embodiment, the second endoprosthetic component  20  includes projections  20   a  that are slidable into resected cavities  12   a  in the first bone  12 . In one embodiment, the total joint replacement  10  further includes a middle endoprosthetic component  22  that is positioned between the first and second endoprosthetic components  18 ,  20  to provide a three piece total joint replacement  10 . The first endoprosthetic component  18  may include a rib  18   a  for preventing lateral movement of the middle endoprosthetic component  22  relative to the first endoprosthetic component  18 . The first endoprosthetic component  18  may also include a fin  18   b  for extending into the second bone  14  and stabilizing the total joint replacement  10  relative to the second bone  14 . 
         [0071]    In one embodiment, the first endoprosthetic component  18  has the approximate dimensions set forth in Table 1 below. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 First Endoprosthetic Component Dimensions (in mm) 
               
             
          
           
               
                   
                 XX - Small 
                 X-Small 
                 Small 
                 Medium 
                 Large 
               
               
                   
                   
               
             
          
           
               
                 ML Dimension (Width) 
                 28 
                 30 
                 34 
                 36 
                 38 
               
               
                 AP Dimension (Depth) 
                 29 
                 31 
                 35 
                 35 
                 35 
               
               
                   
               
             
          
         
       
     
         [0072]    In one embodiment the second endoprosthetic component  20  has the approximate dimensions set forth in Table 2 below. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Second Endoprosthetic Component Dimensions (in mm) 
               
             
          
           
               
                   
                 X-Small 
                 Small 
                 Medium 
                 Large 
                 X-Large 
               
               
                   
                   
               
             
          
           
               
                 ML Dimension (Width) 
                 30 
                 32 
                 32.5 
                 33 
                 33.5 
               
               
                 AP Dimension (Depth) 
                 30 
                 30 
                 35 
                 40 
                 45 
               
               
                   
               
             
          
         
       
     
         [0073]    Though further description herein of the first and second bones  12 ,  14  may refer to the tibia  12  and talus  14  and respective anatomical directions, the instrumentation and methods disclosed herein are not limited to the tibia  12 , talus  14 , fibula  16  and respective anatomical directions. The first, second and third bones  12 ,  14 ,  16  as disclosed herein may be any jointed bones such as the elbow, knee, shoulder or knuckle or a portion thereof that are prepared for the installation or implantation of the total joint replacement  10  or an endoprosthetic component from any direction. The various instrumentation and methods described below may be used in different orientations depending on the application and reference to anatomical orientation as used herein is for exemplary purposes. Additionally, though a left ankle  24  and foot  26  are shown and described, the various instrumentation and methods described below may be used in conjunction with and/or oriented for use with the right ankle (not shown or illustrated) or another applicable joint. 
         [0074]    Alignment Guide 
         [0075]    Referring to the embodiment of  FIG. 3 , an alignment guide  30  may be used to assist in implanting the total joint replacement  10 . The alignment guide  30  may be used to orient one or more instruments, such as first and second tissue resection guides  66 ,  90  relative to the first bone  12  as described further below. The alignment guide  30  includes a first end  30   a  and a second end  30   d . The alignment guide  30  may include a first body  30   b  proximate the first end  30   a  and a second body  30   c  proximate the second end  30   d . In one embodiment, the first and second bodies  30   b ,  30   c  are each comprised of one or more generally cylindrical elongated rods. However, the first and second bodies  30   b ,  30   c  may have any suitable configuration and shape such as a tube that encloses a leg  84  (see  FIG. 17 ). The alignment guide  30  may include a pin receiver  32 . The pin receiver  32  may be proximate the first end  30   a . The pin receiver  32  may include a slot  32   a  and/or a plurality of apertures (not shown) for receiving one or more pins  34  at a plurality of lateral positions. The pin receiver  32  may also move up and down the pin  34  as described further below. In one embodiment, the pin receiver  32  includes a first securement  36  such as a manually adjustable screw that secures the pin receiver  32  to the pin  34  and prevents the alignment guide  30  from moving relative to the pin  32 . In one embodiment, the pin  32  is a self drilling pin and is approximately 3.2 mm in diameter. However, the pin  32  may have any suitable configuration and size. 
         [0076]    An attachment block  38  may be connected to the second body  30   c  of the alignment guide  30 . The attachment block  38  may be configured to secure the second end  30   d  of the alignment guide  30  to the first bone  12 . The attachment block  38  may serve as a datum for one or more resections as described further below. In one embodiment, the second body  30   c  of the alignment guide  30  is telescopically connected to the first body  30   b  of the alignment guide  30 . In one an embodiment, the second body  30   c  of the alignment guide  30  may be fixed with respect to the first body  30   a  of the alignment guide  30  through use of a second securement  40 . The second securement  40  may be a manually adjustable screw. Alternatively, the length of the alignment guide  30  may be fixed and the attachment block  38  may adjust relative to the alignment guide  30 . The attachment block  38  may include one or more apertures  38   a  each for receiving a pin  42 . In one embodiment, the pins  42  may be inserted through the attachment block  38  at an angle such as an oblique angle as shown in  FIG. 3 . The pins  42  may be comprised of Kirschner or K-wire. In one embodiment the pins are approximately 2.4 mm in diameter. However, the pins  42  may have any suitable configuration and diameter. Though the same reference number is used for the additional pins  42  described below, the additional pins  42  described below may be generally identical or different than the pins  42  used to secure the attachment block  38  relative to the first bone  12 . 
         [0077]    The attachment block  38  may include one or more space adjustments  48  that may be threadably received in a respective aperture  38   b . One or more space adjustments  48 , such as a manually adjustable screw, may be provided to stabilize the attachment block  38  relative to the first bone  12 . The space adjustment  48  may alternatively or in addition help to position the attachment block  38  a distance normal to the first bone  12  by extending below the attachment block  38  an adjustable distance. 
         [0078]    An alignment rod  44  is optionally spaced laterally from the alignment guide  30  and is configured to be positionable alongside the first bone  12 . In one embodiment, the alignment rod  44  is generally parallel with the first body  30   b  of the alignment guide  30 . An X-ray image intensifier, such as a C-arm or other imaging device (not shown), may be used to align the alignment rod  44  generally parallel with a feature  12   f  of the first bone  12 . In one embodiment the alignment rod  44  is aligned to be generally parallel to the longitudinal axis of the first bone  12 . The alignment rod  44  may be attached to the first body  30   b  of the alignment guide  30  by an arm  44   a . A grip member or positioning tool  46  such as a T-grip may releasably connect or attach to the attachment block  38  to assist in orienting the attachment block  38  relative to the first bone  12 . In one embodiment, the grip member  46  is generally perpendicular to a longitudinal axis of the alignment guide  30  in an engaged position. 
         [0079]    Referring to the embodiment of  FIG. 4 , the attachment block  38  may include a first positioning block  50 . In one embodiment, the attachment block  38  is fixed relative to the first bone  12  and the first positioning block  50  is movable relative to the attachment block  38 . In one embodiment, the first positioning block  50  is adjustable relative to the attachment block  38  in first and second directions, e.g. superior and inferior anatomical directions, that are generally parallel to the length of the alignment guide  30 . The attachment block  38  may include a first key adjustment  52  that may be configured to set the distance between the attachment block  38  and the first positioning block  50 . In one embodiment, the first key adjustment  52  engages a first rack  54  that extends from the first positioning block  50  and into the attachment block  38 . Alternatively, the first rack  54  may extend from the attachment block  38  and extend into the first positioning block  50 . The first key adjustment  52  may be turned using a tool such as a gear key or screw driver (not shown). Alternatively, the key adjustment  52  may be a manually adjustable screw. The attachment block  38  optionally includes a first position lock  56  that releasably fixes the distance between the attachment block  38  and the first positioning block  50 . In one embodiment, the first position lock  56  is a set screw. However, the first position lock  56  may be any locking device such as projection extending into the first key adjustment  52 . 
         [0080]    The first positioning block  50  may include one or more pin apertures  50   a  each for receiving a pin  42  that extends into the first bone  12 . In one embodiment, the first positioning block  50  includes a first plurality of pin apertures  50   a . The first plurality of apertures  50   a  may be provided to move the first positioning block  50  a predetermined distance with respect to the one or more pins  42  for measuring additional resection of the first bone  12  if necessary as described further below. The first plurality of pin apertures  50   a  may include a first pin aperture  50   b  spaced a predetermined distance from a second pin aperture  50   c  in a direction generally parallel to the length of the alignment guide  30 , e.g. in an inferior anatomical direction. In one embodiment, a third pin aperture  50   d  is spaced a predetermined distance from the second pin aperture  50   c  in a direction generally parallel to the length of the alignment guide  30 , e.g. in an inferior anatomical direction. The first plurality of pin apertures  50   a  may include additional apertures  50   a.    
         [0081]    In one embodiment, the first and second pin apertures  50   b ,  50   c  are spaced from each other a distance equal to the space between the second and third pin apertures  50   c ,  50   d . In one embodiment, the first positioning block  50  includes a second plurality of pin apertures  50   a ′. The second plurality of pin apertures  50   a ′ may include first, second and third pin apertures  50   b ′,  50   c ′,  50   d ′ that each correspond in placement along the first positioning block to respective first, second and third pin apertures  50   b ,  50   c ,  50   d  of the first plurality of pin apertures  50   a . In one embodiment, the predetermined intervals between adjacent pin apertures  50   a ,  50   a ′ are each generally 0.5 mm to generally 5 mm such that the positioning block may be moved relative to the pins  42  the predetermined distance and 0.5 mm to 5 mm of additional tissue can be resected from the end of the first bone  12  in one or more additional resections. In one embodiment, the predetermined intervals between adjacent pin apertures  50   a  are approximately 2 mm. Alternatively, the first positioning block  50  is movable relative to the pins  42  such as having expanding and contracting ends (not shown) or the positioning block  50  may include a slot (not shown) that releasably engages one or more pins  42  to adjust the position of the first positioning block  50  relative to the first bone  12 . 
         [0082]    The attachment block  38  may include a second positioning block  58  that is movable relative to the portion of the attachment block  38  fixed relative to the first bone  12 . In one embodiment, the second positioning block  58  is movable relative to the first positioning block  50 . Alternatively, the first and second positioning blocks  50 ,  58  are integral. The second positioning block  58  may be adjustable relative to the attachment block  38  in third and fourth directions, e.g. lateral and medial anatomical directions, that may be generally perpendicular to the length of the alignment guide  30 . The first positioning block  50  may include a second key adjustment  60  that is used to adjust the position of the second positioning block  58  relative to the attachment block  38 . 
         [0083]    In one embodiment, the second key adjustment  60  engages a second rack (not visible) that extends along the second positioning block  58 . The second key adjustment  60  may be turned using a tool such as a gear key or screw driver (not shown) to move the second positioning block  58  relative to the first positioning block  50 . Alternatively, the second key adjustment  60  may be a manually adjustable screw. The second rack may be alternatively attached to the first positioning block  50 . The first positioning block  50  optionally includes a second position lock  62  that releasably fixes the lateral alignment between the second positioning block  58  and the first positioning block  50  to prevent unintentional movement between the first and second positioning blocks  50 ,  58 . In one embodiment, the second position lock  62  is a set screw. However, the second position lock  62  may be any locking device such as projection extending into the second key adjustment  60 . 
         [0084]    In one embodiment, the second positioning block  58  includes first and second grooves  58   a ,  58   b  on opposing lateral sides of the second positioning block  58 . The first and second grooves  58   a ,  58   b  may be receive and mate with the positioning tool  46  and additional instrumentation as described below to prevent movement between the second positioning block  58  and the positioning tool  46  or additional instrumentation. The positioning tool  46  may be used to assist in positioning the attachment block  38  relative to the first bone  12 . The second positioning block  58  may include a threaded aperture  58   d  for securing to additional instrumentation as described below. The second positioning block  58  may include one or more apertures  58   c  each for viewing the first bone  12  during positioning of the attachment block  38  using a C-arm or other imaging device. In one embodiment, the apertures  58   c  show up on the imaging device as circular if the attachment block  38  is correctly positioned with respect to the first bone  12  and oval shaped if the attachment block  38  is misaligned with respect to the first bone  12 . The apertures  58   c  may generally align with where the cavities  12   a  ( FIG. 1 ) are to be drilled. 
         [0085]    First Tissue Resection Guide 
         [0086]    Referring to the embodiment of  FIG. 5 , a first tissue resection guide  66  may be provided for resecting the first bone  12  and exposing a first resected tissue surface  100  as described below. In one embodiment, the first resected tissue surface  100  is bone tissue. In alternative embodiments, the first resected tissue surface  100  is another tissue such as cartilage and/or a combination of different tissue. The first tissue resection guide  66  may removably attach to the second positioning block  58 . The first tissue resection guide  66  may include a fastener  68  that releasably attaches the first tissue resection guide  66  to the aperture  58   d  (see  FIG. 4 ) in the second positioning block  58 . In one embodiment, the fastener  68  is an Allen screw. However, the fastener  68  may be any attachment device such as a snap or magnet. The first tissue resection guide  66  may include first and second projections  66   a ,  66   b  (see  FIGS. 7 and 8  for the second projection  66   b ) that may be received in the first and second grooves  58   a ,  58   b , respectively of the second positioning block  58 . The first and second projections  66   a ,  66   b  may help to prevent the first tissue resection guide  66  from moving or rotating with respect to the second positioning block  58 . 
         [0087]    In one embodiment, the first tissue resection guide  66  includes a first guide path  70  for resecting the first bone  12 . The first guide path  70  may be a slot  70   a  such that the guide path captures a tissue resection tool such as a blade (not shown). The slot  70   a  may be generally rectangular and oriented such the blade is captured and guided in a direction generally perpendicular to the length of the first bone  12 , e.g. the medial and lateral anatomical directions. The blade may be guided at a slight angle relative the longitudinal axis of the first bone  12  as described further below. An end surface  58   e  of the second positioning block  58  (see  FIG. 4 ) and the first guide path  70  may define a resection plane. In an alternative embodiment, the first guide path  70  is open toward one lateral side (not shown) such that the first tissue resection tool is guided on only one side. The slot  70   a  may include pin apertures  70   b ,  70   c  at the ends of the slot  70   a  for inserting pins  42  (not shown). The pins  42  may be used to protect features of the first and third bones  12 ,  16  such as medial and lateral malleolus  12   e ,  16   a . The first bone  12  may be cut until the first tissue resection tool contacts the pins  42 . The pins  42  may prevent over or notched cuts in the first bone  12 . 
         [0088]    In one embodiment, the first tissue resection guide  66  includes a second guide path  72 . The second guide path  72  is optionally provided to guide the tissue resection tool for a second resection. The second guide path  72  may be generally perpendicular to the blade guard  70 . In one embodiment, the second guide path  72  is open toward one lateral side and defines only one side of a resection plane. In an alternative embodiment, the second guide path  72  is closed similar to the first guide path  70  to capture the blade on two opposing sides (not shown). 
         [0089]    The first tissue resection guide  66  may include indicia  74  indicating which foot (i.e. left or right)  26  the first tissue resection guide  66  is to be used on. The indicia  74  may also, or in the alternative, indicate a size of the first tissue resection guide  66 . The first tissue resection guide  66  may include an indent  66   c  on each lateral side of the first tissue resection guide  66  to aide in gripping the first tissue resection guide  66  during insertion and removal from the second positing block  58 . 
         [0090]    Spacer Guide 
         [0091]    Referring to the embodiment of  FIG. 6 , a spacer guide  78  may be provided for positioning the first and second positioning blocks  50 ,  58  relative to the attachment block  38  and a feature  12   c  of the first bone  12  ( FIGS. 17-20 ). Because the attachment block  38  may be attached to the first bone  12  proximate the feature  12   c , the spacer guide  78  may be used to adjust the first and second positioning blocks  50 ,  58  and position the end surface  58   e  of the second positioning block  58  in the appropriate position. The spacer guide  78  may be used in conjunction with a C-arm or other imaging device to position the end surface  58   e  of the second positioning block  58  a predetermined distance from the feature  12   c  of the first bone  12 . In one embodiment, the feature  12   c  is a superior aspect of the tibial plafond of the tibia (see  FIG. 20 ). 
         [0092]    The spacer guide  78  may include an extension arm  80  extending downwardly from a body  78   a  of the spacer guide  78 . In one embodiment, the extension arm  80  is curved inwardly toward the body  78   a  during use of the spacer guide  78  such that the extension arm  80  curves around the outside of the patient&#39;s anatomy, e.g. leg  84 . However, the extension arm  80  may be straight or outwardly curved and have any shape. 
         [0093]    The spacer guide  78  may include a projection or mount  82  extending downwardly from the body  78   a  and spaced laterally from the extension arm  80 . The mount  82  may be configured to snugly fit within the slot  70   a  of the first guide path  70 . The body  78   a  optionally includes a grip  78   b  such as an aperture extending through the body  78   a  to aid in grasping the spacer guide  78  between two fingers. The extension arm  80 , the body  78   a  and the mount  82  may be generally planar and parallel to one another. 
         [0094]    The extension arm  78  may include one or more projections  86  extending from the extension arm  80  and spaced a predetermined distance from the mount  82  in order to measure the distance from the slot  70   a  of the first guide path  70 . In one embodiment, the projections  86  are pins. The projections  86  may extend through the extension arm  80  such that the projections  86  extend from either side of the extension arm  78  allowing the spacer guide  78  to be used on either lateral side of the ankle  24 . In one embodiment, the predetermined distance, i.e. the length of each projection from each side of the extension arm  80  is approximately 1 mm to approximately 10 mm. In one embodiment, the projections  86  extend approximately 5 mm from the extension arm  80 . In one embodiment, there are 6-8 projections  86 . However, their may be any number of projections  86  having any configuration. The projections  86  may each include a plurality of distance markings such as ribs or include projections  86  having different lengths so that multiple predetermined distances can be ascertained using a single spacer guide  78 . Alternatively, the extension arm  80  and/or body  78   a  may be curved or spaced from the mount  82  in the normal direction from the body  78   a  such that the extension arm  80  is spaced from the mount  82  the predetermined distance in the normal direction from the body  78   a  without the need for projections  86 . The extension arm  80  may alternatively be adjustable relative to the mount  82  such that the predetermined distance may be altered by adjusting a feature or adjusting the orientation of the extension arm  80  relative to the body  78   a . The extension arm  80  may alternatively have a thickness equal to the predetermined distance from the mount  82  for measuring the predetermined distance. 
         [0095]    Second Tissue Resection Guide 
         [0096]    Referring to the embodiment of  FIG. 7 , a second tissue resection guide  90  may be provided to resect tissue from the second bone  14  using, for example, the first tissue resection tool (not shown). The second tissue resection guide  90  may be mounted to the second bone  14  relative to the placement of the attachment block  38 . In one embodiment, the second tissue resection guide  90  is configured to mount over the first tissue resection guide  66  such that the second bone  14  is resected relative to the first resected tissue surface  100  ( FIG. 21 ). The second tissue resection guide  90  may include a mount  92  for securing the second tissue resection guide  90  to first tissue resection guide  66 . The mount  92  may be configured to receive the fastener  68  used to secure the first tissue resection guide  66  to the second positioning block  58 . 
         [0097]    In one embodiment, a tab  98  extends downwardly from the second tissue resection guide  90  to contact the first bone  12 . The tab  98  may contact the first resected tissue surface  100  of the first bone  12  to help stabilize the second tissue resection guide  90  relative to the first bone  12 . In an alternative embodiment of the second tissue resection guide  90 , the second tissue resection guide  90  includes an integral component that is shaped and configured similar to the first tissue resection guide  66  such that after using the first tissue resection guide  90 , the first tissue resection guide  66  is removed from the second positioning block  58  and the second tissue resection guide  90  with the integral first tissue resection guide  66  is mountable directly to the second positioning block  58 . 
         [0098]    The second tissue resection guide  90  may include a guide path  94  for guiding and capturing a tissue resection tool such as the first tissue resection tool, e.g. a blade (not shown). The second tissue resection guide  90  may be configured to guide a tissue resection tool that is different or the same from the tissue resection tool used with the first tissue resection guide  66 . The first tissue resection tool may be used with the second tissue resection guide  90  to expose a resected or second surface  104  (see  FIG. 22 ) of the second bone  14 . In one embodiment, the second resected tissue surface  104  is bone. In alternative embodiments, the second resected tissue surface  104  is another tissue such as cartilage and/or a combination of different tissue. 
         [0099]    In one embodiment, the second tissue resection guide  90  may be configured such that one side of the guide path  94  is generally flush or parallel with an outer end  66   d  ( FIG. 5 ) of the first tissue resection guide  66  such that the guide path  94  and the outer end  66   d  of the first tissue resection guide  66  define a resection plane. In one embodiment, the first and second tissue resection guides  66 ,  90  are configured so that when engaged with each other, the guide path  94  is spaced from the slot  70   a  of the first guide path  70  a predetermined distance. In one embodiment, the predetermined distance between the guide path  94  and the slot  70   a  of the first guide path  70  is approximately 1 mm to approximately 8 mm. In one embodiment, the predetermined distance between the guide path  94  and the slot  70   a  of the first guide path  70  is approximately 4 mm. The predetermined distance between the guide path  94  and the slot  70   a  of the first guide path  70  may be generally equal to the thickness of the first guide path  70 . The guide path  94  may include one or more recesses  94   a  each for receiving pins (not shown) to adjust the length of the guide path  94  and limit the amount that the second bone  14  is resected. 
         [0100]    The second tissue resection guide  90  may include one or more pin mounts  96 . The pin mounts  96  may be used to support pins  42  that secure the second tissue resection guide  90  to the second bone  14  (see  FIG. 20 ). In such an embodiment, the second bone  14  is held relative to the attachment block  38 . In an alternative embodiment, the guide path  94  may include a generally open side such that the first tissue resection tool is only supported or guided on one side. 
         [0101]    Referring to the embodiment of  FIG. 8 , a second tissue resection guide  90 ′ may include a tab extension  102  that extends further downwardly from the tab  98 ′ such that the tab extension  102  is sandwiched between and contacts both the first resected tissue surface  100  and the not yet resected second bone  14  when initially in place on the first tissue resection guide  66  (see  FIG. 21 ). In one embodiment, the second tissue resection guide  90  is used for normal to tight joints and the second tissue resection guide  90 ′ with the tab extension  102 ′ is used for lax joints. In one embodiment, the tab extensions  102  are approximately 1 mm to approximately 10 mm thick depending on how lax the joint is. In one embodiment, the second tissue resection guides  94 ′ are provided with tab extensions  102  in approximately 2 mm, 4 mm or 6 mm thicknesses. In one embodiment, the tab extension  102  is generally flat and bulbous shaped such that the tab extension  102  sufficiently contacts the first resected tissue surface  100 . However, the tab extension  102  may be any shape such as rectangular, triangular or square. 
         [0102]    Datum 
         [0103]    Referring to the embodiment of  FIG. 9A-9C , a datum  108  may be provided for releasably engaging at least one tissue resection guide as described further below. The datum  108  may provide a fixed reference point on the second bone  14  to make one or more resections to the second bone  14  relative or in reference to the datum  108 . The datum  108  may also include one or more surfaces and/or one or more edges that are aligned with a feature of the tissue resection guide (e.g. a guide path) to form a resection plane an example of which is described in more detail below. The datum  108  may assist in directly guiding and supporting the various resection tools. In one embodiment, the datum  108  allows for multiple resections adjacent to the datum using two or more resections guides while only attaching one device to the second bone  14 , e.g, the datum  108 . 
         [0104]    In one embodiment, the datum  108  is a parallelepiped. However, the datum  108  may be generally shaped and sized such that resections guided at least partially by the datum  108  conform to an upper interior (not shown) of the first endoprosthetic component  18 . Though the datum  108  may have planar sides, the datum  108  may alternatively have one or more curved or stepped sides. The shape of the datum  108  may generally correspond to the shape required to fully resect an end of the second bone  14  using a predetermined number of generally planar resection planes. In one embodiment, the datum  108  includes four generally planar resection planes. The use of the datum  108  may help to minimize the amount of tissue that is resected from the second bone  14  by reducing recutting, reshaping and over resection caused by free-hand cutting, miss-measurements, measuring off of other cuts and/or misplacement of resection guides. 
         [0105]    In one embodiment, the datum  108  includes first, second, third and forth sides  108   a ,  108   b ,  108   c ,  108   e . In one embodiment, a bottom  108   d  of the datum  108  is sized and configured to contact a tissue surface (e.g., the second resected tissue surface  104 ). In one embodiment, the datum  108  has at least one side (e.g., one of sides  108   a ,  108   b ,  108   c ,  108   e ) that is generally in-line or parallel to a resected tissue surface such as a tissue surface (e.g. one of surfaces  104   a ,  104   b ,  104   c ,  104   d ) such as in a manner described below after the resections to the second bone  14  are made. The first second and third sides  108   a ,  108   b ,  108   c  of the datum  108  may each be angled inwardly such that they each extend at an acute angle from the base or bottom  108   d  ( FIG. 9C ). In one embodiment, the top of the fourth side  108   e  may extend outwardly such that the fourth side  108   e  extends at an obtuse angle from the bottom  108   d . The second and third sides  108   b ,  108   c  may be angled inwardly toward each other proximate the first side  108   a  about an axis perpendicular to the bottom  108   d  such that the second and third sides  108   b ,  108   c  each extend from the fourth side  108   e  at an acute angle measured on a plane parallel to the bottom  108   d . In one embodiment, the first side  108   a  is generally ninety degrees from the fourth side  108   e  as measured on a plane parallel to the bottom  108   d . In one embodiment, the third side  108   c  is angled inwardly proximate the first side  108   a  about an axis perpendicular to the bottom  108   d . An angle of inclination defined by the intersection of the third side  108   c  and a plane normal to the bottom  108   d  may be greater than an angle of inclination defined by the intersection of the second side  108   b  and a plane normal to the bottom  108   d  as illustrated in  FIG. 9B . At least one side  108   a ,  108   b ,  108   c ,  108   e  of the datum  108  may be sized and configured to at least partially contact and guide a tissue resection tool as described further below. In one embodiment, the first, second, third and fourth sides  108   a ,  108   b ,  108   c ,  108   e  of the datum  108  are posterior, medial, lateral and anterior sides respectively. 
         [0106]    The datum  108  optionally includes a datum mount  110 . The datum mount  110  may include a threaded aperture  110   a . The datum mount  110  may include a recessed section  110   b  for further engaging at least one tissue resection guide and for receiving a datum securement  122  of a distractor  120  (see, e.g.,  FIG. 10D ). The recessed section  110   b  may have a generally cube-like shape. However, the recessed section  110   b  may have any shape such as pyramid, spherical-like or approximations thereof. 
         [0107]    The datum  108  may include at least one pin aperture  112  for receiving a pin  42  or a shoulder pin  114 . The pin aperture  112  may include a shoulder  112   a  to limit depth of the shoulder pins  114  ( FIG. 25 ). The pins  114  may be received at an angle relative to the bottom  108   d  such that the pins  114  extend upwardly from the datum  108  toward the fourth side  108   e  of the datum  108 . In one embodiment, the datum  114  includes a pair of pin apertures  120  spaced on medial/lateral sides of the datum mount  110  such that when pinned to the second resected tissue surface  104 , the datum  108  does not rotate relative to the second resected tissue surface  104 . 
         [0108]    The datum  108  may include indicia  116  such as a colored polymeric plug that indicates the size and/or shape of the datum  108 . In one embodiment, the indicia  116  is positioned on a non-tissue contacting surface. In one embodiment, the indicia  116  is located on a surface opposite a surface that is a tissue contacting surface such as, for example, the bottom  108  in the embodiment illustrated in  FIG. 9C . 
         [0109]    Distractor 
         [0110]      FIGS. 10A-10C  illustrates one embodiment of a distractor  120 . The distractor  120  may be sized and configured to place, orient and/or insert the datum  108  onto a tissue surface, e.g. the second resected tissue surface  104 . The distractor  120  may additionally be used to distract or separate the first resected tissue surface  100  from the second resected tissue surface  104  and provide sufficient space to place the datum  108  and attach resection guides thereto. The distractor  120  may include a handle  129  and a datum securement  122  and a tissue engaging portion  134  attached to the handle  129 . At least a portion of the handle  129  may extend along a handle axis  120   a . In one embodiment, the handle  129  includes a first or lower handle  130  and a second or upper handle  136 . 
         [0111]    The datum securement  122  may be configured to releasably engage the datum  108 . The datum securement  122  may releasably engage the datum  108  in an insertion position ( FIG. 10A ) and or during positioning of the datum  108  on the second resected tissue surface  104  ( FIGS. 24 and 25 ). In one embodiment, the datum securement  122  includes at least one projection  122   a . The projection  122   a  may be oriented to project from the datum securement  122  at an angle relative to the axis  120   a . Projections  122   a  may be sized, configured and oriented to extend into the datum mount  110  of the datum  108 . However, the datum securement  122  may include any suitable device for releasably engaging or securing the datum  108  such as a threaded attachment or a magnet. 
         [0112]    In one embodiment, the distractor  120  includes an abutment member  124  proximate the datum securement  122 . The abutment member  124  may be fork shaped such that the datum  108  is engaged by ends  124   a  on either sides of the projection  122   a  to provide at least three points of contact with the datum  108  such that the datum  108  is securely held and does not move relative to the distractor  120 . However, the abutment member  124  may have any suitable shape including one or more surface or point of contact end  124   a . The ends  124   a  of the abutment member  124  may be slanted or otherwise shaped and configured to be generally parallel to the fourth side  108   e  of the datum  108 . The abutment member  124  may be slidable relative to a lower handle  130  extending from the datum securement  122 . The abutment member  124  may be slid toward the datum projection  122   a  to pinch the datum  108  between the datum projection  122   a  and the abutment member  124 . Alternatively, the datum projection  122   a  may be moved relative to the abutment member  124 . The abutment member  124  may have a recessed or stepped distal bottom surface  124   b  ( FIG. 10D ) such that the abutment member  124  is generally flush or parallel with the bottom surface  108   d  of the datum  108 . The remainder of the abutment member  124  may be thicker than the distal bottom surface  124   b  to strengthen the abutment member  124 . 
         [0113]    In one embodiment, the abutment member  124  includes a datum lock  126  configured to move the datum datum securement  124  from a secured position to a released position. The datum lock  126  may include a rotatable nut  126   a  that threadably engages a shaft  124   c . In one embodiment, the shaft  126   c  is integral with the abutment member  124 . In an alternative embodiment, the shaft  124   c  is integral with the nut  126   a  and the threaded shaft  124   c  extends into the abutment member  124 . The datum securement  122  may include a stop  128  ( FIG. 10E ) that engages with the abutment member  124  when the datum  108  has been secured with the distractor  120  to prevent over extending the abutment member  124  and exerting a pinching force on the datum  108  that may damage the datum projection  122   a  and/or the datum  108 . 
         [0114]    In one embodiment, the lower handle  130  extends from the datum securement  122 . The lower handle may be generally aligned with the handle axis  120   a . The lower handle  130  may include a grip  132 . In one embodiment, the grip  132  is integral with the lower handle  128  and may include a plurality of indentations  132   a . Alternatively, the grip  132  may be a separate component and/or have a textured surface. 
         [0115]    The distractor  122  may include a tissue engaging portion  134 . In one embodiment, the upper handle  136  extends from the tissue engaging portion  134 . The upper handle  136  may include a distal portion  136   e  attached to the tissue engaging portion  134  and a grip portion  136   f  attached to the distal portion  136   e . The grip portion  136   f  of the upper handle  136  may include a plurality of grips  136   a . In one embodiment, the grips  136   a  include a plurality indentations  136   a  separated by columns that are oriented perpendicular to a longitudinal axis  120   a  of the handle  130 . The grips  136   a  may have any suitable shape such as scalloped or cylindrical. 
         [0116]    The distal portion  136   e  and the grip portion  136   f  may be joined at an inflection or pivot point  136   d . In one embodiment, the grip portion  136   f  of the upper handle  136  extends from the inflection point  136   f  at an angle relative to the lower handle  130  as shown in  FIG. 10A . The distal portion  136   e  may be generally parallel with the axis  120   a  in an insertion position. The upper handle  136  may extend from the inflection point between a range of angles that allows a user to grip the upper and lower handles  136 ,  130  with one hand while allowing sufficient movement of the tissue engaging portion  134  relative to the datum  108 . In one embodiment, the upper handle  136  may extend from the inflection point at approximately 30 degrees as shown in  FIG. 10A . The upper handle  136  may be convexly shaped away from the lower handle  130  so as to make the upper handle  136  closer to being parallel with the lower handle  130  to make gripping of the distractor  120  easier. In one embodiment, the upper handle  136  is pivotable with respect to the lower handle  130  such that squeezing the upper and lower handles  130 ,  136  together spaces the tissue engaging portion  134  from the datum securement  122 . In one embodiment, the lower handle  130  is releasably attached to the upper handle  136 . The lower handle  130  may include a socket  130   a  that rotatably supports an axle (not visible) on the upper handle  136 . In one embodiment, the socket  130   a  is partially open, e.g. C-shaped, such that the upper handle  136  is removable proximally from the lower handle  130 . The axle of the upper handle  136  may be spring biased within the socket  130   a  by a first biasing member  138 . The first biasing member  138  may be a cantilever spring. In an alternative embodiment, the lower and upper handles  130 ,  136  have a scissor orientation such that the lower handle  130  extends from the tissue engaging portion  134  and the upper handle  136  extends from the datum securement  122 . 
         [0117]    In one embodiment, the tissue engaging portion  134  includes a paddle  140  configured to engage the first resected tissue surface  100 . The paddle  140  may be pivotably attached to the upper handle  136  such that the paddle  140  remains at a generally constant angle during separation of the first and second bones  12 ,  14  to maintain contact with the first resected tissue surface  100  during distraction of the first and second bones  12 , 14 . In one embodiment, the paddle  140  may remain generally parallel to the second resected tissue surface  100  as the tissue engaging portion  134  is pivoted from the datum securement  122 . The paddle  140  and upper handle  136  may be pivotable about axes that are generally parallel to one another. 
         [0118]    In one embodiment, a portion of the paddle  140  may be at least partially narrower than the space between the pin apertures  112  of the datum  108  such that the paddle  140  can be slid out between the shoulder pins  114  after securing the datum  108  to the second resected tissue surface  104 . In one embodiment, the paddle  140  includes an enlarged end  140   a . In one embodiment, the enlarged end  140   a  is wider than the space between the pin apertures  112  of the datum  108  to provide, for example, increased surface area for contacting the first resected tissue surface  100  and keeping surrounding tissue clear from the second resected tissue surface  104 . The paddle  140  may also be enlarged toward the enlarged end  140   a  to provide more weight proximal to the axis of rotation such that paddle  140  tends to lay parallel with the extending upper handle  136  when released. The paddle  140  may be partially recessed within the extending upper handle  136  such that the paddle  140  is nearly flush and/or parallel with the upper handle  136  in the insertion position. In one embodiment, the paddle  140  may include one or more ribs  140   c  ( FIG. 10C ) that extends downwardly from the paddle  140  into a recess  136   b  of the upper handle in the insertion position. In one embodiment, the ribs  140   c  may be provided to generally stiffen and minimize bending of the enlarged end  140   a  while allowing the paddle  140  to be generally flush or parallel with the upper handle  136 . 
         [0119]    The proximal ends  136   c ,  130   b  of the upper and lower handles  136 ,  130  may be connected by a ratchet  142  such that distractor  120  can be held in a distracted position ( FIG. 25 ) without a user having to continually squeeze the handles  130 ,  136 . The ratchet  142  may include a plurality of teeth  142   a  that engage a projection (not shown) of the upper handle  136  and prevent the upper handle  136  from returning to the insertion position. The ratchet  140  may be spring biased via a second biasing member  144 . In one embodiment, the second biasing member  144  is a cantilever spring secured to the lower handle  130 . 
         [0120]    In one embodiment, the upper handle  136  may be removed from the lower handle  130  if distraction of the first and second resected tissue surfaces  100 ,  104  is not necessary (e.g. for a lax joint) and/or to disengage and the ratchet  142  such that the upper handle  136  is freely pivotable relative to the lower handle  130 . The ratchet  142  may be disengaged from the upper handle  136  by pulling back on the ratchet, removing the upper handle  136  from the lower handle  130  and pivoting the ratchet  142  downwardly so that it lies on the lower handle  130  ( FIG. 10D ). Once the ratchet  142  has been disengaged from the upper handle  136 , the upper handle  136  re-attached to the lower handle  130  such that the distractor  120  functions without the ratchet  142 . The ratchet  142  optionally includes a grip  142   b  that extends upwardly past or through the upper handle  136  such that the ratchet  142  may be gripped and pulled rearwardly or proximally to disengage the ratchet  140  from the upper handle  136 . In one embodiment, the grip  142   b  is an indent. The grip  142   b  of the ratchet  142  may receive a portion of the datum lock  126  in the folded position ( FIG. 10D ) such that the ratchet  142   b  may lie flat against the lower handle  130 . Alternatively, the ratchet  142  may have a shorter length than shown such that the datum lock  126  may be used while the ratchet  142  lies against the lower handle portion  130 . 
         [0121]    Third Tissue Resection Guide 
         [0122]    Referring to the embodiment of  FIGS. 11A-11B , a third tissue resection guide  146  may be provided for resecting, for example, the second bone  14 . The third tissue resection guide  146  may be sized and configured to releasably attach to the top side  108   f  of the datum  108  and guide one or more tissue resection tools. In one embodiment, the third tissue resection guide  146  is an anterior/posterior tissue resection guide for resecting the second bone  14  anterior and posterior to the datum  108 . The third tissue resection guide  146  may be used to resect the second bone  14  in any direction relative to the datum  108 . The third tissue resection guide  146  includes a base  148  that releasably engages the datum  108 . The base  148  may include a datum projection  148   a  that extends from the base  148  and fits within the recessed section  108   d  of the datum  108  to prevent the third tissue resection guide  146  from rotating with respect to the datum  108 . The datum projection  148   a  may include an aperture  148   b  for receiving a fastener  150  configured to secure the third tissue resection guide  146  to the datum  108 . In one embodiment, the fastener  150  is an Allen screw. However, the fastener  150  may be any securement device such as a snap. The base  148  may include pin apertures  148   c  for fitting over the shoulder pins  114  extending from the datum  108 . The pin apertures  148   c  may be angled away from the base  148  such that the pins  42  remain out of the way and provide a more stable support from the second bone  14 . 
         [0123]    The third tissue resection guide  146  may include a first frame  152  attached to the base  148 . In one embodiment, the first frame  152  is integral with the base  148 . In one embodiment, the first frame  152  is adjacent to the fourth side  108   e  of the datum  108  when the third tissue resection guide  146  is engaged with the datum  108  (e.g.,  FIG. 28 ). 
         [0124]    The first frame  152  may include or define one or more guide paths (e.g., first and second guide paths  154 ,  156 ). In one embodiment, guide paths  154 ,  156  are apertures within a frame (e.g., the first frame  152 ). In one embodiment, the guide paths  154 ,  156  are elongate apertures. For example, in one embodiment, the guide paths  154 ,  156  are defined by an inner wall  152   a  of a frame (e.g., the first frame  152 ). In the embodiment of  FIG. 11A , for example, the guide paths  154 ,  156  are defined by a continuous inner wall  152   a . In one embodiment, guide paths such as guide path  166  is defined a discontinuous inner wall  160   a . Also as illustrated in  FIG. 11A , guide paths, such as guide paths  154 ,  156  may extend through a frame (e.g., first frame  152 ) such that there is no restriction to a correctly sized tool passing though such a guide path from one side of a frame to another. As will be illustrated in more detail below, a guide path (such as guide path  180   c  of  FIG. 12B  may include a closed upper surface  180   a  to restrict the movement of a resection tool when the resection tool is being guided in the guide path  180   c.    
         [0125]    In one embodiment, the first and second guide paths  154 ,  156  each include an enlarged end  154   a ,  156   a . The enlarged ends  154   a ,  156   a  (e.g., of adjacent guide paths) are optionally on opposite lateral sides of the first frame  152 . In one embodiment, the enlarged end  154   a  of first guide path  154  is proximate the lateral side of the ankle  24  and the enlarged end  156  of the second guide path  156  is proximate the medial side of the ankle  24  during use as shown in the embodiment of  FIGS. 28 and 29  such that a resection tool (e.g. a milling bit)  168  spinning clockwise tends to pull away from the base  148  caused by the contact between the resection tool and the second bone  14 . In one embodiment, the orientation of the enlarged ends  145   a ,  156   a  may be reversed (not shown) for a resection tool  168  spinning in a counterclockwise direction. The first and second guide paths  154 ,  156  may be generally parallel to each other. The first and second guide paths  154 ,  156  may be generally parallel to the fourth side  114   e  of the datum. In one embodiment, the centers  154   b ,  156   b  of the first and second guide paths  154 ,  156  are spaced a distance D.sub.1 that is less than a diameter D.sub.2 of the enlarged end  154   a  of the first guide path  154 . In one embodiment, the spacing of the guide paths  154 ,  156  allows for an overlapping resection path as discussed further below. The center  154   b  of the first guide path  154  may be spaced from the fourth side  108   e  of the datum  108  a distance approximately equal to half of the diameter D.sub.2 of the enlarged end  154   a  of the first guide path  154  such that the resection path nearly abuts the fourth side  108   e  of the datum  108 . The first frame  152  may include one or more pin supports  158  each configured to receive a pin  42  (see  FIG. 27 ) for further stabilizing the third tissue resection guide  146  relative to the second bone  14 . 
         [0126]    In one embodiment, each of the first and second guide paths  154 ,  156  are configured to receive and guide a tissue resection tool such as a second tissue resection tool  168 . (See  FIG. 27 ). The second tissue resection tool  168  may be a milling bit though the second tissue resection tool  168  may be any tissue resection tool such as a blade. The second tissue resection tool  168  may include an enlarged cutting head  168   a . In one embodiment, the cutting head  168   a  fits through the enlarged ends  154   a ,  156   a  of the first and second guide paths  154 ,  156  respectively but does not fit through the remainder of the first and second guide paths  154 ,  156 . The remainder of the first and second guide paths  154 ,  156  may be narrowed from the enlarged ends  154   a ,  156   a  to more closely fit another feature of a resection tool such as the diameter of a shaft  168   b  of the second tissue resection tool  168 . 
         [0127]    In one embodiment, the second tissue resection tool  168  includes a stop  168   c  that abuts a top surface of the first frame  152  to limit the distance the second tissue resection tool  168  extends through the first frame  152  as shown in  FIG. 28 . In one embodiment, the stop  168   c  is rotatable with respect to the shaft  168   b  thereby significantly reducing the amount that the stop  168   c  rotates against and wears the top surface of the first frame  152 . 
         [0128]    The third tissue resection guide  146  is sized and configured to guide the second tissue resection tool  168  proximate the fourth side  108   e  of the datum  108 . In one embodiment, third tissue resection guide  146  is sized and configured to guide the second tissue resection tool  168  to resect the second bone  14  and to further expose the second resected tissue surface  104  in a direction away from the fourth side  108   e  of the datum  108 . In one embodiment, the further exposed second resected tissue surface  104  is a second resected tissue surface expansion  104   b  (best illustrated in  FIGS. 30 and 33 ). In one embodiment, the second resected tissue surface  104  is expanded in the anterior direction. The fourth resected tissue surface  104   b  may be generally normal to the fourth side  108   e  of the datum  108 . In one embodiment, each guide path  154 ,  156  is used to expose the fourth resected tissue surface  104   b . (See  FIGS. 28 and 29 ). The first and second guide paths  154 ,  156  may be configured to allow for overlapping resections by the second tissue resection tool  168  such that the first and second guide paths  154 ,  156  create a planar fourth resected tissue surface  104   b  (See  FIGS. 28 and 30 ). Alternatively, the first frame  152  includes a single guide path  154  or more than two guide paths  154 ,  156 . 
         [0129]    With continued reference to the embodiment shown in  FIGS. 11A and 11B , the third tissue resection guide  146  optionally includes a second frame  160  adjacent to the first side  108   a  of the datum  108 . The third tissue resection guide  146  may be sized and configured to receive and guide a third tissue resection tool  170 . The third tissue resection tool  170  may further expose or expand the second resected tissue surface  104  in a direction away from the datum  108 . (See  FIG. 26 ). In one embodiment, the further exposed second resected tissue surface  104  is a third resected tissue surface  104   a  (best illustrated in  FIGS. 30 and 33 ). Referring to the embodiment of  FIG. 27 , the third tissue resection tool  170  may be a blade with a cutting end  170   a . The third tissue resection tool  170  is configured to slide back and forth within the guide path  166  such that the cutting end  170   a  resects tissue and expands the second resected tissue surface  104  to further expose the third resected tissue surface  104   a.    
         [0130]    The second frame  160  may include a guide path  166 . In one embodiment, the guide path  166  includes a partially open sidewall  160   c  defined by sidewall segments  162 ,  164 . In one embodiment, each sidewall  162 ,  164  extends from the base  148  and wraps around toward each other to define the guide path  166 . Sidewall  162 ,  164  may taper to a center point  162   a ,  164   a . In one embodiment, a benefit of an at least partially open sidewall  160   c  includes permitting a user to view a tissue resection tool within the guide path  166 . In one embodiment, the partially open sidewall  160   c  permits viewing of the third tissue resection tool  170  and/or the third resected tissue surface  104   a  ( FIG. 27 ) while the third tissue resection tool  170  is resecting tissue. 
         [0131]    In one embodiment, a guide path  166  is defined by inner walls  162   b ,  164   b . In one embodiment, a first side  108   a  of the datum  108  and a feature (e.g. an edge  148   f ) of the base  148  are aligned with at least one inner wall of the frame  160  when the third tissue resection guide  146  is engaged with the datum  108 . 
         [0132]    In one embodiment, the guide path  166  may be generally aligned in a plane with the first side  108   a  of the datum  108  when the third tissue resection guide  146  is engaged with the datum. For example, in  FIGS. 27 and 29 , the third tissue resection guide  146  and datum  108  may define a template or resection plane that is aligned with the third resected tissue surface  104   a  and in which the third tissue resection tool  170  is moved along. In one embodiment, the resection plane corresponds to a desired cut surface of a bone to match a feature of the total joint replacement  10 . In one embodiment, the resection plane may be defined by a feature (e.g., inner wall  162   b ) of the second frame  160  or by a combination of one or more features of the second frame  160  and a feature of the base  148 . In one embodiment, sidewalls  162 ,  164  define a slot with inner edge  148   f  that is slightly larger than a preselected thickness of the third resection tool  170  and wider than a preselected thickness of the third resection tool  170  to allow the third resection tool  170  to slide from side to side within the guide path  166  but small enough to constrain undesirable movement away from the base  178 . 
         [0133]    In one embodiment, there are no sidewalls  162 ,  164  on the second frame  160  such that the guide path  166  is entirely open toward one side. In such an embodiment, care should be taken not to contact the medial and lateral malleolus  12   e ,  16   a  rather than rely on the sidewalls  162 ,  164  to stop the second tissue resection tool  170 . In one embodiment, the second frame  160  of the third tissue resection guide  146  has an entirely closed perimeter wall (not shown). In one embodiment, the third resection guide  146  does not include a second frame  160  and the third resected tissue surface  104   a  is exposed by sliding the third tissue resection tool  170  against the first side  108   a  of the datum  108 . The third tissue resection guide  146  may include indicia  172  such as a colored polymeric plug that indicates the size and/or right or left foot  26 . 
         [0134]    Fourth Tissue Resection Guide 
         [0135]    Referring to the embodiment of  FIGS. 12A-12C , a fourth tissue resection guide  176  may be provided for resecting the second bone  14 . The fourth tissue resection guide  176  is sized and configured to releasably attach to the top side  108   f  of the datum  108  (see  FIGS. 31 and 32 ). The fourth tissue resection guide  176  is also configured to receive and guide one or more resection tools to resect tissue at predetermined orientation and location. In one embodiment, a resection using the fourth tissue resection guide  176  is made while fourth tissue resection guide  176  is attached to the datum  108  and while the datum  108  is attached to tissue (e.g., the second resected tissue surface  104 ). In one embodiment, the fourth tissue resection guide  176  is configured to guide one or more tissue resection tools adjacent to the datum  108 . In one embodiment, the fourth resection tool  182  is guided adjacent to one or more sides of the datum  108 . In one embodiment, the fourth resection tool  182  is guided adjacent to different sides of the datum  108  than the sides of the datum  108  that are adjacent to the resections made when the third tissue resection guide  146  is used as described above. In one embodiment, the fourth tissue resection guide  176  is a medial/lateral tissue resection guide for resecting the second bone  14  medial and lateral to the datum  108 . However, the fourth tissue resection guide  176  may be used to resect the second bone  14  in any direction relative to the datum  108 . 
         [0136]    The fourth tissue resection guide  176  includes a base  178  that releasably engages the datum  108 . The base  178  may include a datum projection  178   a  that extends from the base  178  and fits within the recessed section  108   d  of the datum  108  to prevent the fourth tissue resection guide  176  from rotating with respect to the datum  108 . The datum projection  178   a  may include an aperture  178   b  for receiving a fastener  150  configured to secure the fourth tissue resection guide  176  to the datum  108 . In one embodiment, the fastener  150  is an Allen screw. However, the fastener  150  may by any securement device such as a snap or magnet. The fastener  150  may be the same fastener  150  used to secure the third tissue resection guide  146  to the datum  108 . In one embodiment, each of the third and fourth tissue resection guides  146 ,  176  may include its own fastener  150 . The base  178  may include pin apertures  178   c  for fitting over the shoulder pins  114  extending from the datum  108 . In one embodiment, the fourth tissue resection guide  176  is integral with the third tissue resection guide  146 . The base  178  may include one or more grips  178   d  (see  FIG. 12A ) that are configured to engage an insertion tool (not shown) such as forceps. In one embodiment, the grips  178   d  may be apertures as shown. 
         [0137]    The fourth tissue resection guide  176  may include a first frame  180  attached to the base  178  (e.g., such that the first frame  180  is integral with the base  178  or a separate component that is combined with the base  178 ). In one embodiment, the first frame  180  is adjacent to the second side  108   b  of the datum  108  when the fourth tissue resection guide  176  is engaged with the datum  108  and is configured to receive and guide a tissue resection tool such as the fourth tissue resection tool  182 . (See  FIG. 31 ). 
         [0138]    The first frame  180  may include a guide path  180   c  for capturing and guiding the fourth tissue resection tool  182 . In one embodiment, the guide path  180   c  is a generally planar elongated slot. In one embodiment, the guide path  180   c  is defined at least in part by an inner surface  180   g  of the first frame  180  and an outer surface  178   g  of the base  178 . When the fourth tissue resection guide  176  is engaged with the datum  108  the guide path  180   c  may be further defined, at least in part, by the second side  108   b  of the datum  108 . 
         [0139]    In one embodiment, the guide path  180   c  of the first frame  180  is at least partially closed proximate a top  178   f  of the base  178  via a closed top  180   a . In one embodiment, the guide path  180   c  is substantially open proximate the bottom  178   e  of the base  178 . In one embodiment, the closed top  180   a  and open bottom of the guide path  180   c  permit the resection tool to move freely in a direction toward the second bone  12  but restricts the resection tool in a direction normal to the base  178  such that the resection tool may be slid downwardly out of the fourth resection guide  176  but not upwardly out of the fourth resection guide  176 . The closed top  180   a  may be provided so that the fourth tissue resection tool  182  can be pivoted up against the closed top  180   a  during use. The closed top  180   a  may include a rounded inner edge  180   b  to contact the fourth tissue resection tool  182  and prevent a pointed contact between the first frame  180  and the fourth tissue resection tool  182 . The first frame  180  may be open toward the bottom  178   e  of the base  178  such that the fourth tissue resection tool  182  may extend downwardly past the base  178  and resect the second bone  14  to further expose a fifth resected tissue surface  104   c . The guide path  180   c  may be generally parallel to the second side  108   b  of the datum  108  when the fourth tissue resection guide  176  is engaged with the datum  108 . Alternatively, the guide path  180   c  may be defined solely by the first frame  180  or solely between the first frame  180  and the base  178 . In one embodiment, the guide path  180   c  of the first frame  180  is a generally rectangular slot. 
         [0140]    In one embodiment, the fourth tissue resection tool  182  is a saw blade. However, the fourth tissue resection tool  182  may be any suitable resection device such as any one of the first, second and third tissue resection tools  168 ,  170  described above (the first tissue resection tool is not shown). 
         [0141]    The first frame  180  of the fourth tissue resection guide  176  may include at least one viewing window  186  extending through an outer side  180   d  of the first frame  180 . In one embodiment, the first cut guide  180  includes two viewing windows  186   a ,  186   b . The outer side  180   d  of the first frame  180  may include an alignment feature such as an alignment line  188  (best shown in  FIG. 31 ) that extends across or intersects the at least one viewing window  186  such that during use the depth of the fourth tissue resection tool  182  can be determined by aligning a feature  182   a  of the fourth tissue resection tool  182  such as the top edge of the fourth tissue resection tool  182  with the alignment line  188 . (See  FIG. 31 ). In one embodiment, the alignment line  188  is cut or etched into the outer side  180   d  of the first frame  180 . Alternatively, the alignment line  188  may be printed or otherwise affixed to the outer side  180   d  of the first cut guide  180 . The first frame  180  may be used to resect or expose the fifth resected tissue surface  104   c . (See  FIGS. 31 and 32 ). 
         [0142]    Referring to  FIGS. 31 and 32 , in one embodiment, the fifth resected tissue surface  104   c  extends medially from the second resected tissue surface  104 . In one embodiment, the fifth resected tissue surface  104   c  is generally parallel with the second side  108   b  of the datum  108 . In one embodiment, approximately 0.5 mm to approximately 6 mm of tissue may be removed from second bone  14  to expose the fifth resected tissue surface  104   c . In one embodiment, approximately 2 mm to approximately 3 mm of tissue is removed from second bone  14  proximal the second side  108   b  of the datum  108 . The inferior extending length of the fifth resected tissue surface  104   c  may be approximately 5 mm to approximately 15 mm. In one embodiment, the inferior extending length of the medial extension  106   c  is approximately 10 mm. 
         [0143]    The fourth tissue resection guide  176  may include a second frame  190  attached to the base  178 . In one embodiment, the second frame  190  is a general mirror image of the first frame  180 . In one embodiment, the second frame  190  and the first frame  180  are attached to the base  178  in a general symmetrical configuration (see, e.g.,  FIGS. 12A and 12B ). In one embodiment, the second frame  190  and the first frame  180  are oriented to provide guides that facilitate serial medial and lateral resections while the fourth tissue resection guide  176  is attached to the datum  108  and the datum  108  is attached to the second bone  14  (e.g., without the need to detach and attach a cut guide to the second bone  14  between medial and lateral resections). 
         [0144]    In one embodiment, the second frame  190  is adjacent to the third side  108   c  of the datum  108  when the fourth tissue resection guide  176  is engaged with the datum  108  and is configured to receive and guide a tissue resection tool such as the fourth tissue resection tool  182  (similar to the first frame  180  shown in  FIG. 31 ). In one embodiment, the second frame  190  is integral with the base  178  or a separate component that is combined with the base  178 . The second frame  190  may include a guide path  190   c  for capturing and/or guiding the fourth tissue resection tool  182 . In one embodiment, the guide path  190   c  is defined at least in part by an inner surface  190   g  of the first frame  190  and an outer surface  178   h  of the base  178 . When the fourth tissue resection guide  176  is engaged with the datum  108 . The guide path  180   c  may be further defined, at least in part, by a third side  108   c  of the datum  108 . 
         [0145]    In one embodiment, the guide path  190   c  of the second frame  190  is at least partially covered or closed proximate a top  178   f  of the base  178  via a closed top  190   a . In one embodiment, the guide path  190   c  is substantially open proximate the bottom  178   e  of the base  178 . In one embodiment, the closed top  190   a  and open bottom permit the resection tool to move freely in a direction toward the second bone  12  but restricts the resection tool in a direction normal to the base  178  such that the resection tool may be slid downwardly out of the fourth resection guide  176  but not upwardly. The closed top  190   a  may be provided so that the fourth tissue resection tool  182  can be pivoted up against the closed top  190   a  during use. The closed top  190   a  of the second frame  190  may include a rounded inner edge  190   b  to contact the fourth tissue resection tool  182  and prevent a pointed contact between the first frame  190  and the fourth tissue resection tool  182 . The second frame  190  may be open toward the bottom  178   e  of the base  178  such that the fourth tissue resection tool  182  may extend downwardly past the base  178  and resect the second bone  14  to further expose a sixth resected tissue surface  104   d . The guide path  190   c  may be generally parallel to the third side  108   c  of the datum  108  when the fourth tissue resection guide  176  is engaged with the datum  108 . Alternatively, the guide path  190   c  may be defined solely by the second frame  190  or solely between the second frame  190  and the base  178 . In one embodiment, the guide path  190   c  of the second frame  190  is a generally rectangular slot. 
         [0146]    The second frame  190  of the fourth tissue resection guide  176  may include at least one viewing window  192  extending through an outer side  190   d  of the second frame  190 . In one embodiment, the second frame  190  includes two viewing windows  192   a ,  192   b . The outer side  190   d  of the second frame  190  may include an alignment line  194  (best shown in  FIG. 12A ) that extends across the at least one viewing window  192  such that during use the depth of the fourth tissue resection tool  182  can be determined by aligning a feature  182   a  of the fourth tissue resection tool  182  such as the top edge of the fourth tissue resection tool  182  with the alignment line  194 . In one embodiment, the alignment line  194  is cut or etched into the outer side  180   d  of the second frame  190 . Alternatively, the alignment line  194  may be printed or otherwise affixed to the outer side  190   d  of the second frame  190 . The second frame  190  may be used to resect or expose a sixth resected tissue surface  104   d . (See  FIG. 32 ). 
         [0147]    Referring to  FIG. 32 , in one embodiment, the sixth resected tissue surface  104   d  extends laterally from the second resected tissue surface  104 . In one embodiment, the sixth resected tissue surface  104   d  is generally parallel with the second side  108   b  of the datum  108 . Approximately 0.5 mm to approximately 6 mm of tissue may be removed from second bone  14  to expose the sixth resected tissue surface  104   d . In one embodiment, approximately 2 mm to approximately 3 mm of tissue is removed from second bone  14  proximal the third side  108   c  of the datum  108 . The inferior extending length of the sixth resected tissue surface  104   d  is approximately 10 mm to approximately 25 mm. In one embodiment, the inferior extending length of the sixth resected tissue surface  104   d  is approximately 17 mm. 
         [0148]    In one embodiment, (e.g., as illustrated in  FIG. 12A ) the second frame  190  is angled about an axis that is generally perpendicular to the top  178   f  of the base  178  such that the front edge  190   e  is angled inwardly toward the base  178 . In one embodiment, the first frame  180  is angled about an axis that is generally perpendicular to the top  178   f  of the base  178  such that the front edge  180   e  is angled inwardly toward the base  178  (not illustrated). In one embodiment (e.g., as illustrated in  FIG. 12B ), the first frame  180  and/or second frame  190  are angled toward each other such that the closed tops  180   a ,  190   a  extend inwardly. In one embodiment, the angle of inclination of the first frame  180  and the second frame  190  are different. In one embodiment, the angles of inclination of the first and second frames  180 ,  190  are approximately equal to the angles of inclination of the respective second and third sides  108   b ,  108   c  of the datum  108 . 
         [0149]    In one embodiment, the ends  180   e ,  190   e  extend outwardly from the body  178  and generally taper to a point to protect surrounding tissue from the fourth tissue resection tool  182 . However, the ends  180   e ,  190   e  of the first and second frames  180 ,  190  may have any shape and may or may not extend outwardly further from the body  178 . In one embodiment, the top  180   a  of the first cut guide  180  extends further from the base  178  than the top  190   a  of the second cut guide  190  to allow for a deeper resection proximate the third side  108   c  of the datum  108  than the resection proximate the second side  108   b  of the datum  108 . However, the first and second cut guides  180 ,  190  may be configured to make a similar depth cut or be oriented to make any desired resections proximate and relative to the datum  108 . In one embodiment, the fourth tissue resection tool  182  includes vertically extending teeth  182   c  such that the teeth  182   c  do not contact the first or second cut guides  180 ,  190  during use. 
         [0150]    Window Trial 
         [0151]    Referring to the embodiment of  FIG. 13 , there is shown a window trial  198 . The window trial  198  may include one or openings  200  to evaluate the resected second bone  14 . The window trial  198  may be used to evaluate the second, third, fourth, fifth and sixth resected tissue surface tissues  104 ,  104   a ,  104   b ,  104   c ,  104   d . (See  FIGS. 33 and 34 ). The window trial  198  may have an inner surface  198   a  that generally has the shape of an inner surface of the second endoprosthetic component  18  of the total joint replacement  10 . The window trial  198  may have an outer surface  198   b  that generally has the shape of an outer surface of the first endoprosthetic component  18  of the total joint replacement  10 . In one embodiment, the window trial  198  has the same shape and configuration as the first endoprosthetic component  18  of the total joint replacement  10 . 
         [0152]    In one embodiment, the window trial  198  includes the one or more openings  200  for viewing and evaluating the shape of one or more of the second, third, fourth, fifth and sixth resected tissue surfaces  104 ,  104   a ,  104   b ,  104   c ,  104   d ,  104   e . The window trial  198  may include side openings  200   a ,  200   b  proximate the fifth and sixth resected tissue surface  104   c ,  104   d  respectively. In one embodiment, the side openings  200   a ,  200   b  are generally aligned or parallel with the fifth and sixth resected tissue surface  104   c ,  104   d  respectively such that the fifth and sixth resected tissue surfaces  104   c ,  104   d  are not visible if the resections are proper when viewing the fifth and sixth resected tissue surfaces  104   c ,  104   d  at a viewing angle that is parallel and in-line with the fifth and sixth resected tissue surfaces  104   c ,  104   d  respectively. In one embodiment, first and second top openings  200   c ,  200   d  expose the second and fourth resected tissue surfaces  104 ,  104   b  respectively. The first and second top openings  200   c ,  200   d  may each expose the second resected tissue surface  104  proximate the third resected tissue surface  104   a  such that the inner surface  198   a  of the window trial  198  proximate the third resected tissue surface  104   a  is visible. 
         [0153]    The window trial  198  may include a fin aperture  200   e . In one embodiment, a keel mill or wire driver (not shown) is used to cut a keel slot (not shown) into the second  14  using the fin aperture  200   e  as a guide. The keel slot may be made for receiving the fin  18   b  of the first endoprosthetic component  18 . The window trial  198  may include one or more pin apertures  204  for securing the window trial  198  to the second bone  14  using one or more pins  42 . The window trial  198  optionally includes a handle  202  to assist in installing and removing the window trial  198  from the second bone  14  using a tool such as forceps (not shown). The window trial  198  may include indicia (not shown) such as a colored polymeric plug or printed graphic that indicates the size and/or right or left foot  26 . 
         [0154]    Barrel Cut Guide 
         [0155]    Referring to the embodiment of  FIG. 17 , a barrel cut guide  208  may be provided. The barrel cut guide  208  may be configured to guide a fifth tissue resection tool  210  used to form the resected cavities  12   a  that receive the projections  20   a  of the second endoprosthetic component  20 . (See  FIGS. 1 and 2 ). In one embodiment, the fifth tissue resection tool  210  is a drill bit. In one embodiment, the barrel cut guide  208  includes a support plate  212 . The support plate  212  may contact the first resected tissue surface  100  during use. The support plate  212  may also be used to measure the first resected tissue surface  100  for the appropriately sized second endoprosthetic component  20 . In one embodiment, various support plates  212  are provided that correspond to the size of the second endoprosthetic component  20 . In an alternative embodiment, the support plate  212  is partially transparent and includes various size markings for determining the size of the second endoprosthetic component  20 . 
         [0156]    The barrel cut guide  208  may be fixed to the first bone  12  by one or more pins  42 . The barrel cut guide  208  may include a height adjuster  214  that may be used to space the barrel cut guide  208  an appropriate distance from the first bone  12 . The space between the barrel cut guide  208  may be adjusted using the height adjuster  214  after the pins  42  are set if the pins  42  are inserted generally parallel with the height adjuster  214  or the length of height adjuster  214  extending from the barrel cut guide  208  may be set prior to inserting the pins  42  if the pins are inserted at an angle as shown. In one embodiment, the height adjuster  214  is a manually adjustable screw. However, the height adjuster  214  may be any device suitable to space the barrel cut guide  208  from the first bone  12 . 
         [0157]    The barrel cut guide  208  may include a body  216  that extends generally perpendicular from the support plate  212  such that the body  216  extends at least partially over the top of the first bone  12 . The body  216  may include two apertures  216   a  (only one shown in  FIG. 35 ) that are generally sized and shaped similar to the projections  20   a  of the second endoprosthetic component  20  and guide the fifth tissue resection tool  210 . The fifth tissue resection tool  210  may include a shoulder  210   a  that contacts the body  216  and a maximum drilling depth to limit the depth of the resected cavities  12   a  a predetermined distance. 
         [0158]    Referring to the embodiment of  FIG. 15 , the resected cavities  12   a  may be opened or exposed through the first resected tissue surface  100  using a fin cutter  218  that is inserted through the apertures  216   a ,  216   b  of the barrel cut guide  208 . In one embodiment, the fin cutter  218  includes a pair of fins  220  that are generally parallel and spaced apart from one another. The fins  220  may be configured to cut perpendicularly through the first resected tissue surface  100  through the resected cavities  12   a . The support plate  212  may include slots  212   a ,  212   b  for receiving the fins  220  and the bone that is cut out by the fins  220 . The fin cutter  218  may include a shaft  218   a  that is generally equal in size to the resected cavities  12   a  and a limit stop  218   b  that contacts the body  216  once the fins  220  have reached the end of the resected cavities  12   a.    
         [0159]    Method of Use 
         [0160]    Referring to  FIGS. 16-35 , there are shown exemplary embodiments of using the various instrumentation disclosed above for implanting the total joint replacement  10 . Referring to  FIG. 16 , after the foot  26  and ankle  24  have been correctly positioned, the foot  26  and ankle  24  are preferably elevated. The foot  26  and ankle  24  are elevated for approximately two minutes. A high thigh tourniquet (not shown) may be inflated or tightened with an appropriate amount of pressure for the size of the leg  84  and foot  26 . An incision  224  may be made along the anterior side of the ankle  24  parallel to the leg  84  to expose the joint between the tibia  12  and the talus  14 . The incision  224  may be approximately 5 cm to approximately 30 cm in length. In one embodiment, the incision  224  is approximately 20 cm in length. The incision  224  may be centered over the ankle  24  immediately lateral to an anterior tibial tendon (not shown). The incision  224  may be deepened into the ankle  224  while moving the extensor hallucis longus (not shown) and the neurovascular bundle laterally. The incision  224  may expose the superficial dorsal peroneal nerve (not shown) and should be retracted carefully to the lateral side. In one embodiment, it may be necessary to sacrifice one branch of the superficial dorsal peroneal nerve that goes to the first metatarsal. The incision  224  may open the tendon sheath of the extensor hallucis longus (not shown) inline with the incision  224 . In one embodiment, every effort is made not to open the anterior tibial tendon sheath (not shown) as such action might cause bolstering of the tendon during closing of the incision  224 . 
         [0161]    After the extensor hallucis longus tendon sheath is opened, the deep peroneal nerve and artery (not shown) which are just beneath the tendon sheath, may be retracted laterally in a gentle manner. The capsular tissues (not shown) in the ankle  24  may be incised in line with the incision  224  and then elevated and mobilized to expose the medial malleolus  12   b  (see  FIG. 1 ) and the entire ankle joint. Care should be taken not to release the anterior talofibular ligament (not shown) as this will produce ankle instability. 
         [0162]    The ankle joint may be distracted slightly using any suitable tool and excess synovium (not shown) and any loose bodies or bone spurs are removed using any suitable technique. In one embodiment, the anterior osteophytes (not shown) are excised so the tibial plafond  12   c  can be visualized. Retractors  226  are optionally used to hold the incision  224  open. In one embodiment, manually positioned retractors  226  are used over self retaining retractors. The retractors  226  may be frequently repositioned to minimize the risk of tissue trauma. 
         [0163]    Referring to  FIG. 17 , the alignment guide  30  may be secured to the first bone  12  by inserting the pin  34  into a first end  12   d  of the first bone  12 . In one embodiment, the first end  12   d  is the anterior tibial tubercle of the tibia. The pin  34  may be oriented approximately perpendicular to first bone  12 . In one embodiment, the alignment guide  30  is positioned relative to the pin  34 , both anteriorly and laterally, and secured to the pin  34  using the first securement  36 . 
         [0164]    In one embodiment, the attachment block  38  is positioned proximate a second end  12   c  of the first bone  12 . In one embodiment, the second end  12   c  is the tibial plafond of the tibia. The positioning tool  46  may be secured to the second positioning block  54  to assist in positioning the attachment block  38  relative to the first bone  12 . The attachment block  38  may be secured to the first bone  12  using one or more pins  42 . The second securement  40  may be tightened to fix the length between the attachment block  38  and the first end  30   a  of the alignment guide  30 . 
         [0165]    In one embodiment, an osteotome (not shown), placed within the medial gutter, is used for additional visualization and setting proper orientation of the attachment block  38 . The space adjustments  48  may be used to stabilize the attachment block  38  with respect to the first bone  12 . In one embodiment, the distance between the attachment block  38  and the first bone  12  is as small as possible. In one embodiment, the attachment block  38  is positioned the approximate distance from the feature  12   c  of the first bone  12  such as the tibial plafond. A C-arm or other imaging device may be used to align the alignment rod  44  generally parallel with the longitudinal axis of the first bone  12 . In one embodiment, the alignment rod  44  is generally aligned with a bone feature  12   f  in the anterior/posterior and lateral views (lateral view shown). In one embodiment, the bone feature  12   f  is the tibial crest of the tibia. 
         [0166]    Referring to  FIG. 18 , once the attachment block  38  has be secured to the first bone  12 , the first tissue resection guide  66  is attached to the second positioning block  58 . 
         [0167]    Referring to  FIGS. 19 and 20 , the spacer guide  78  may be attached to the first tissue resection guide  66  by inserting the mount  82  into the first guide path  70  of the first tissue resection guide  66 . The C-arm or other imaging device may be used to view the ankle  24  from the lateral side proximate the extension arm  80  of the spacer guide  78 . In one embodiment, the projections  86  are used to set the position first positioning block  50 . In one embodiment, a single spacer guide  78  may be used for viewing the ankle  24  from either the medial or lateral side ( FIG. 20 ). The spacer guide  78  may be removed and the C-arm or other imaging device may be used from the anterior side of the ankle  24 . In one embodiment, the first tissue resection guide  66  is positioned by using the second positioning block  58  and by aligning the first guide path  70  between the between the medial and lateral malleolus  12   e ,  16   a.    
         [0168]    Once the position of the first tissue resection guide  66  is determined, pins  42  are inserted into the superior-most pin apertures  50   b ,  50   b ′ of the respective plurality of pin apertures  50   a ,  50   a ′ in the first positioning block  50 . In one embodiment, pins  42  may be placed within the pin apertures  70   a ,  70   b  in the first tissue resection guide  66  to protect the medial and lateral malleolus  12   e ,  16   a . In one embodiment, the first tissue resection tool such as a blade (not shown) is inserted within the first guide path  70  to resect or cut the distal end of the first bone  12  along a first cut line  228  ( FIG. 18 ). The blade may be placed against the second guide path  72  to resect or cut a second cut line  230  ( FIG. 18 ). 
         [0169]    In one embodiment, when the alignment rod  44  is aligned with the feature  12   f  of the first bone  12 , the top of the guide path  94  is angled back toward the alignment guide  30  such that the guide path  94  is at an approximately 87 degree angle with respect to the first bone  12 . This allows for an angled first resected tissue surface  100  as best shown by the angle of the spacer guide  78  in  FIG. 20  and the angle of the second endoprosthetic component  20  in  FIG. 2 . The angle of the guide path  94  relative to the first bone  12  may be altered by raising or dropping the first end  30   a  of the alignment guide  30  along the pin  34 . The angle of the guide path  94  relative to the first bone  12  may be approximately 85 degrees to approximately 95 degrees and may have any orientation when the alignment rod  44  is generally parallel to longitudinal axis of the first bone  12 . Once the guide path  94  is set to the desired positioned, the first resection tool is used to resect the first bone  12  along the first and second cut lines  228 ,  230 . The resections along the first and second cut lines  228 ,  230  expose the first resected tissue surface  100  ( FIG. 20 ). 
         [0170]    Referring to  FIG. 21 , after the first resected tissue surface  100  is exposed, a second tissue resection guide  90  is inserted onto the first tissue resection guide  66 . The foot  26  may be moved to a general plantigrade position (shown) such that the top of the second bone  14  engages the first resected tissue surface  100  or the tab extension  102 ′. The spacer guide  78  may be used to verify neutral positioning of the second bone  14 . In one embodiment, the second tissue resection guide  90  is secured to the second bone  14  by pins  42  extending through the pin mounts  92 . In such an embodiment, the second bone  14  is now fixed relative to the alignment guide  30 . The first tissue resection tool may be inserted within the guide path  94  of the second tissue resection guide  90  to resect or cut the second bone  14  exposing the second resected tissue surface  104 . 
         [0171]    Referring to  FIG. 22 , once the first and second resected tissue surfaces  100 ,  104  have been exposed, a space evaluator  234  may be inserted between the first and second resected tissue surfaces  100 ,  104  to ensure that the proper amount of tissue from the first and second bones  12 ,  14  has been resected. In one embodiment, the space evaluator  234  includes a plurality of finger grips  234   c . The finger grips  234   c  may be inwardly extending grooves positioned on at least one side or lateral edge of the space evaluator  234 . 
         [0172]    The space evaluator  234  may have a predetermined thickness toward a first end  234   a  and a predetermined thickness toward a second end  234   b . In one embodiment, the thickness of the first end  234   a  is approximately 6 mm to approximately 20 mm. In one embodiment, the thickness of the first end  234   a  is approximately 12 mm. For example, the first end  234   a  having a 12 mm thickness may include 3 mm of space for the second endoprosthetic component  20 , 6 mm of space for the middle endoprosthetic component  22  and 3 mm of space for the first endoprosthetic component  18 . If the space evaluator  234  does not fit between the first and second resected tissue surfaces  100 ,  104 , the first bone  12  may be further resected. In one embodiment, the space evaluator  234  has a thinner thickness (e.g. approximately 9 mm) toward a second end  234   b  in the event that the distance measured using the spacer guide  78  is off, the measurement included cartilage or other non-bone tissue or if a joint is lax. In one an embodiment, if the final distance between the first and second resected tissue surfaces  100 ,  104  is thinner than the thickness of the first end  234   a  of the space evaluator  234 , the second end  234   b  of the space evaluator  234  may be inserted between the first and second resected tissue surfaces  100 ,  104  to gauge the additional space needed. For example, if the second end  234   b  of the space evaluator  234  fits snugly between the first and second resected tissue surfaces  100 ,  104  then an additional distance, such as 2 mm, can be resected from the first bone  12 . The first bone  12  may be further resected by removing the pins  42  from first positioning block  50 , moving the first positioning block  50  one or more predetermined length increments (e.g. 2 mm) such that the original pin holes  50   b ,  50   b ′ in the first bone  12  align with the adjacent pin holes  50   c ,  50   c ′ and then reinserting the pins  42  into the first positioning block  50  through the pin holes  50   c ,  50   c′.    
         [0173]    Referring to  FIG. 23 , once there is sufficient space for implanting the total joint replacement  10  between the first and second bones  12 ,  14  the foot  26  may be plantar flexed (shown) to achieve better access to the second resected tissue surface  104 . In one embodiment, a sizer  236  is inserted over the second resected tissue surface  104 . The sizer  236  may be used to measure the size of the second resected tissue surface  104  such as the anterior/posterior depth and the medial/lateral width. In one embodiment, the sizer  236  has a general shape and size of the datum  108 . The appropriately sized datum  108  may be determined by adding, or leaving, a predetermined distance (e.g. 3 mm) to each medial/lateral side of the sizer  234 . In one embodiment, a different sizer  234  is provided for each datum size. In one embodiment, the size of the sizer  234  and right or left foot  26  being measured is indicated by indicia  238  such as printed words (e.g. left ankle, size small). The sizer  234  may included a handle  240  that is color coded to the size of the sizer  234 . In an alternative embodiment, the sizer  234  is at least partially transparent with nested outlines (not shown) of differently sized datum  108  that allow a user to select the appropriate size. In one embodiment, the size of the first endoprosthetic component  18  is verified by measuring the distance between the medial and lateral malleolus  12   e ,  16   a . In one embodiment, the sizer  234  is outlined or traced on the second resected tissue surface  104  using a marking material such as a skin marker to help indicate the position the datum  108 . The sizer  234  may be properly positioned by aligning the handle  240  with a second metatarsal  26   a  of the foot  26 . 
         [0174]    Referring to  FIGS. 24 and 25 , once the appropriately sized datum  108  is selected, the datum  108  is attached and secured to the distractor  120 . In one embodiment, the datum  108  is positioned relative to the alignment block  38  using a guide (not shown). The datum  108  may be inserted onto the second resected tissue surface  104  using the distractor  120  and may be generally positioned within the outline previously marked on the second resected tissue surface  104 . In one embodiment, the datum  108  is positioned on the second resected tissue surface  104  by aligning the distractor  122  with the second metatarsal  26   a . In one embodiment, the C-arm or other imaging device is used to further verify the position of the datum  108  with respect to the second surface  104 . In one embodiment, the paddle  140  engages the first resected tissue surface  100  in the insertion position ( FIG. 24 ) and the upper handle  136  is squeezed toward the lower handle  130  to separate the first resected tissue surface  100  from the second resected tissue surface  104 . The ratchet  142  may hold the upper and lower handles  136 ,  130  in position with respect to each other such that the distractor  120  can be held in a distracted position without having to continually squeeze the handles  130 ,  136 . Alternatively, the ratchet  142  may be disengaged and is folded inwardly to lay on the lower handle  130  (see  FIG. 10D ). 
         [0175]    With the first resected tissue surface  100  distracted from the second resected tissue surface in the distraction position ( FIG. 25 ), the datum  108  may be secured to the second resected tissue surface  104  by inserting the shoulder pins  114  through the pin apertures  112  of the datum  108 . Once the datum  108  is sufficiently secured to the second resected tissue surface  104 , the distractor may be returned to the insertion position ( FIG. 24 ), the datum lock  126  is released and the distractor  120  is removed from the ankle  24  leaving the datum  108  in place on the second resected tissue surface  104  ( FIG. 26 ). 
         [0176]    Referring to  FIG. 27 , once the datum  108  has been secured to the second resected tissue surface  104 , the third tissue resection guide  146  is releasably secured to the datum  108 . A second tissue resection tool  170  may be inserted within the second frame  160  and guided by the guide path  166  of the second frame  160  to resect the second bone  14  relative to the datum  108  and expose the third resected tissue surface  104   a . In one embodiment, the second tissue resection tool  170  is slid back and forth within the second frame  160  and along the first side  108   a  of the datum  108  such that the cutting end  170   a  resects tissue proximate the datum  108 . The second tissue resection tool  170  may be viewed through the open perimeter  160   c . In one embodiment, the second tissue resection tool  170  is removed from the third tissue resection guide  146  to inspect the third resected tissue surface  104   a.    
         [0177]    Referring to  FIG. 28 , the third tissue resection tool  168  may be inserted within the enlarged end  154   a  of first guide path  154  of the third tissue resection guide  146 . In one embodiment, the third tissue resection tool  168  is inserted until the stop  168   c  of the third tissue resection tool  168  abuts the first frame  152 . The third tissue resection tool  168  may be guided proximate the fourth side  108   e  of the datum  108  to resect or cut the second bone  14  and expand the second resected tissue surface  104  away from the fourth side  108   e  of the datum  108 . In one embodiment, the fourth side  108   e  of the datum  108  nearly contacts the head  170   a  of the third tissue resection tool  170 . The third tissue resection tool  168  may be guided back along the first guide path  154  and the cutting head  168   a  may be removed from the first guide path  154  through the enlarged end  154   a.    
         [0178]    Referring to  FIG. 29 , in one embodiment, the third tissue resection tool  168  is inserted within the enlarged end  156   a  of second guide path  156 . The third tissue resection tool  168  may be inserted until the stop  168   b  of the third tissue resection tool  168  abuts the first frame  152  of the third tissue resection guide  146 . The third tissue resection tool  168  is guided proximate the fourth side  108   e  of the datum  108  to resect or cut the second bone  14  and expand the second resected tissue surface  104  away from the fourth side  108   e  of the datum  108 . The third tissue resection tool  168  is guided back along the second guide path  156  and the cutting head  168   a  is removed from the second guide path  156  through the enlarged end  156   a.    
         [0179]    Referring to  FIG. 30 , the third tissue resection guide  146  may be removed from the datum  114  revealing the third and fourth resected tissue surfaces  104   a ,  104   b  left after use of the third tissue resection guide  146 . 
         [0180]    Referring to  FIGS. 31 and 32 , the fourth tissue resection guide  176  may be releasably secured to the datum  108 . In one embodiment, the datum  108  remains in the same position on the second resected tissue surface  104  for use with both the third and fourth tissue resection guides  146 ,  176 . Once the fourth tissue resection guide  176  is secured to the datum  114 , the fourth tissue resection tool  182  may be inserted into the first guide path  180   c  of the first frame  180 . In one embodiment, the fourth tissue resection tool  182  is inserted into the first guide path  180   c  of the first frame  180  in the posterior anatomical direction until a feature such as the depth marking  182   a  of the fourth tissue resection tool  182  aligns with a feature of the first frame  180  such as an edge  180   f . The fourth tissue resection tool  182  may be slid and/or pivoted downwardly though the first guide path  180   c  until the upper edge  182   b  of the fourth tissue resection tool  182  aligns with the alignment line  188 . The proximal end of the fourth tissue resection tool  182  may be pulled upwardly to contact the edge  180   b  of the first frame  180  to thereby pivot the distal end of the fourth tissue resection tool  182  downwardly toward and into the second bone  14 . 
         [0181]    In one embodiment, the fourth tissue resection tool  182  is inserted into the second guide path  190   c  of the second frame  190 . In one embodiment, the fourth tissue resection tool  182  is inserted into the second guide path  190   c  in the posterior anatomical direction until a feature such as the depth marking  182   a  of the fourth tissue resection tool  182  aligns with a feature of the second frame  190  such as an edge  190   f . The fourth tissue resection tool  182  may be slid and/or pivoted downwardly though the second guide path  190   c  until the upper edge  182   b  of the fourth tissue resection guide  182  aligns with the alignment line  194 . The proximal end of the fourth tissue resection guide  182  may be pulled upwardly to contact the edge  190   b  to thereby pivot the distal end of the fourth tissue resection guide  182  downwardly toward and into the second bone  14 . 
         [0182]    Referring to  FIG. 33 , the fourth tissue resection guide  176  and the datum  108  may be removed from the second bone  14  to expose the second third, fourth, fifth and sixth resected tissue surfaces  104 ,  104   a ,  104   b ,  104   c ,  104   d . In one embodiment, the resected tissue surfaces  104 ,  104   a ,  104   b ,  104   c ,  104   d  are inspected for any burrs and/or missed or miss cut portions. The resected tissue surfaces  104 ,  104   a ,  104   b ,  104   c ,  104   d  may be resected further if necessary using the instrumentation above and/or through free hand resection. 
         [0183]    Referring to  FIG. 34 , the window trial  198  may be used to further evaluate the second resected tissue surface  104  and the various cuts made to the second bone  14 . The window trial  198  may be installed or inserted over the second resected tissue surface  104  using a tool, such as forceps, attached to the handle  202 . If the resections made to the second bone  14  are off, the inner surface  198   a  of the window trial  198  will be at least partially raised off of the second resected tissue surface  104  and/or tissue will be visible through one or more of the openings  200 . In one embodiment, if the window trial  198  does not fit and/or if excess tissue is visible through the openings  200 , a bone rasp (not shown) or other resection device is used to clean up the resections and provide a better fit with the window trial  198  and ultimately the first endoprosthetic component  18 . The window trial  198  may be pinned to the second bone  14  using one or more pins  42 . A keel mill or wire driver (not shown) may be used to cut a keel slot (not shown) into the second bone  14  using the fin aperture  200   e  as a guide. In one embodiment, a keel broach (not shown) is used to clean any remaining tissue in the keel slot. 
         [0184]    Referring to  FIG. 35 , the barrel cut guide  208  may be attached to the first bone  12 . In one embodiment, the barrel cut guide  208  is configured to utilize the same pins  42  and/or pin holes in the first bone  12  that were used to secure the first positioning block  50  to the first bone  12 . In one embodiment, the support plate  212  is generally flush against the first resected tissue surface  100 . The position of the barrel cut guide  208  toward and away from the first bone  12  may be adjusted with the height adjuster  214 . The window trial  198  may be left on the second resected tissue surface  104  to protect the second resected tissue surface  104  during installation and use of the barrel cut guide  208 . In one embodiment, a joint spacer  242  having the general shape and size of the middle endoprosthetic component  22  of the total joint replacement  10  is inserted between the window trial  198  and the support plate  212  to keep the support plate  212  in contact with the first resected tissue surface  100 . The joint spacer  242  may also be used to determine the appropriate size and shape of the middle endoprosthetic component  22 . 
         [0185]    A fifth tissue resection tool  210  may be inserted into the apertures  216   a  of the barrel cut guide  208  to create the resected cavities  12   a . (See  FIG. 1 ). A barrel broach (not shown) may be used to clean the cavities  12   a  of remaining bone. The resected cavities  12   a  may be opened or exposed through the first resected tissue surface  100  by using the fin cutter  218 . The fin cutter  218  is inserted into the apertures of the barrel cut guide  208  to remove the section of bone between the resected cavities  12   a  and the first resected tissue surface  100  such that the projections  20   a  may extend from the second endoprosthetic component  20  into the resected cavities  12   a . The resected bone may be removed from the ankle  24  by any suitable technique. 
         [0186]    In one embodiment, the size of the resected cavities  12   a  is assessed using a trial bearing  244 . (See  FIG. 14 ). The window trial  198 , the joint spacer  242  and the barrel cut guide  208  may be removed from the ankle  24 . The first endoprosthetic component  18  may be inserted over the second resected tissue surface  104 . In one embodiment, an impactor (not shown) is used to seat the first endoprosthetic component  18  on the second resected tissue surface  104 . A notched end  234   d  of the space evaluator  234  (see  FIG. 10 ) may be used to lift an anterior edge of the first endoprosthetic component  18  and drive the posterior of the first endoprosthetic component  18  inferiorly in an effort to seat the first endoprosthetic component  18  on the second resected tissue surface  104 . In one embodiment, the second endoprosthetic component  20  is implanted or mounted using an insertion device (not shown). The projections  20   a  may be aligned with the resected cavities  12   a . In one embodiment, a mallet (not shown) is used to gently drive the second endoprosthetic component  20  downwardly and into position on the first bone  12 . An anterior edge of the second endoprosthetic component  20  may be flush with the anterior tibial cortex. In one embodiment, a sponge (not shown) is placed over the first endoprosthetic component  18  to protect the first endoprosthetic component  18  while the second endoprosthetic component  20  is being inserted. Variously sized and shaped joint trials or spacers  242  may be inserted between the first and second endoprosthetic components  18 ,  20  to evaluate desired joint tension and position. After a satisfactory reduction is accomplished, the joint spacer  242  may be replaced with the appropriate middle endoprosthetic component  22 . The incision  24  may then be closed. 
         [0187]    The bone removed from the first and second bones  12 ,  14  using the above instrumentation and methods may be kept to a minimum. In one embodiment, the reduced amount of bone resection achieved as a result of the above procedures means that if the total joint replacement  10  needs to be removed and a salvage ankle joint fusion performed, the patient will not have a noticeable leg-length discrepancy. 
         [0188]    Tissue Resection Kit 
         [0189]    In one embodiment, a tissue resection kit (not explicitly shown) for implanting the total joint replacement  10  is provided and includes any combination of the above instrumentation. In one embodiment, the tissue resection kit includes the datum  108  and one or more tissue resection guides (e.g., the third and fourth resection guides  146 ,  176 ) that are size and configured to releasably engage the datum  108  and guide a tissue resection tool. In one embodiment, the tissue resection guide of the tissue resection kit includes the third tissue resection guide  146 . In one embodiment, tissue resection guide of the tissue resection kit includes the fourth tissue resection guide  176 . The tissue resection kit may include the first tissue resection guide  66 . The tissue resection kit may include the spacer guide  78 . The tissue resection kit may include the second tissue resection guide  90 . The tissue resection kit may include the sizer  236 . The tissue resection kit may include the distractor  120 . The tissue resection kit may include the window trial  198 . The tissue resection kit may include the barrel cut guide  208 . The tissue resection kit may include the fin cutter  218 . In one embodiment, the tissue resection kit includes more than one of the same instrument or component but of various sizes. The tissue resection kit may include instrumentation for one of the left and right ankle  24 . The tissue resection kit optionally includes instrumentation for both left and right ankle  24 . 
         [0190]    It will be appreciated by those skilled in the art that changes could be made to the exemplary embodiments shown and described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the exemplary embodiments shown and described, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. For example, specific features of the exemplary embodiments may or may not be part of the claimed invention and combinations of disclosed embodiments may be combined. The words “right”, “left”, “lower” and “upper” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the device. Unless specifically set forth herein, the terms “a”, “an” and “the” are not limited to one element but instead should be read as meaning “at least one”. 
         [0191]    Further, to the extent that the methods do not rely on the particular order of steps set forth herein, the particular order of the steps should not be construed as limitation on the claims. The claims directed to the method of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the steps may be varied and still remain within the spirit and scope of the present invention. 
         [0192]    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.