Apparatus for knee surgery and method of use

Abstract

The present invention comprises a set of instruments and a method for their use in preparing a knee joint to receive knee implants. The inventive instruments and method are generally suitable for knee joint surgery. Furthermore, they include features that make them suitable for performing a minimally invasive knee surgery in which a smaller than normal incision is made and oriented to preserve the quadriceps mechanism and protect the suprapatellar pouch. The instruments permit switching from a minimally invasive technique to a standard open technique at any point in the procedure. An illustrative set of instruments for total knee arthroplasty and an associated minimally invasive technique are described.

What is claimed is:  
     
         1 . A patella resection guide for guiding a cutter to cut a patella having an anterior side, an opposite posterior side, a medial side and a lateral side, the patella resection guide comprising: 
 a first jaw for engaging said medial side of said patella;    a second jaw for engaging said lateral side of said patella;    means for moving the first jaw relative to the second jaw from a first position in which the jaws are disengaged from said medial and lateral sides of said patella to a second position in which the jaws are engaged with said medial and lateral sides of said patella, the means being actuable from a location that is medial or lateral of said patella; and    means for guiding a cutter to cut said patella.    
     
     
         2 . The patella resection guide of  claim 1  further comprising means for gauging the amount of bone to be resected.  
     
     
         3 . The patella resection guide of  claim 1  further comprising means for gauging the amount of bone that will remain after the patella is cut.  
     
     
         4 . A patella resection guide for guiding a cutter to cut a patella having an anterior side, an opposite posterior side, a medial side and a lateral side, the patella resection guide comprising: 
 a first jaw shaped to engage said medial side of said patella;    a second jaw shaped to engage said lateral side of said patella;    a handle connecting the first and second jaws in translating relationship, the handle being actuable to move the jaws from a first position in which the jaws are disengaged from said medial and lateral sides of said patella to a second position in which the jaws are engaged with said medial and lateral sides of said patella, the handle being actuable from a location that is medial or lateral of said patella.    
     
     
         5 . The patella resection guide of  claim 4  wherein the jaws are have curved faces for engaging curved sides of said patella.  
     
     
         6 . The patella resection guide of  claim 4  wherein the handle comprises a guide arm connecting the first and second jaws, at least one of the first and second jaws mounted for translation along the guide arm to move from the first position to the second position.  
     
     
         7 . The patella resection guide of  claim 6  wherein the jaws remain parallel as they are moved from the first to second positions.  
     
     
         8 . The patella resection guide of  claim 7  wherein the handle comprises an actuator pivotably mounted on the handle at a first end and connected to one of said first and second jaws at a second end such that pivoting the actuator moves the jaws between the first and second positions.  
     
     
         9 . The patella resection guide of  claim 6  wherein the handle further comprises a first grip portion connected to the first jaw and a second grip portion connected to the second jaw, the first and second grip portions being parallel to one another, such that pressing the first and second grip portions together in parallel manner causes at least one of the first and second jaws to translate along the guide arm from the first position to the second position.  
     
     
         10 . The patella resection guide of  claim 4  further comprising a depth gauge removably mountable on the first side of the resection guide to indicate the amount of bone to be removed from said patella and alternately mountable on the second side of the resection guide to indicate the amount of bone to remain on said patella.  
     
     
         11 . The patella resection guide of  claim 4  further comprising a cutter guide to guide a cutter.  
     
     
         12 . The patella resection guide of  claim 11  wherein the cutter is selected from the list consisting of a saw blade, a side cutting reamer, a end cutting reamer, and a water jet cutter.  
     
     
         13 . A patella resection guide comprising: 
 a first side;    a second side; and    a depth gauge removably mountable on the first side of the resection guide to indicate the amount of bone to be removed from said patella and alternately mountable on the second side of the resection guide to indicate the amount of bone to remain on said patella.    
     
     
         14 . A patella resection guide for guiding a cutter to cut a patella having an anterior side, an opposite posterior side, and a periphery around the patella, the patella resection guide comprising: 
 a first jaw member shaped to engage said periphery of said patella;    a second jaw member shaped to engage said periphery of said patella, the second jaw member connected to the first jaw member in translating relation;    a first handle connected to the first jaw member;    a second handle connected to the second jaw member, the second handle being actuable to move the second jaw member in a motion plane toward and away from the first handle; and    a cutter guide adjacent the jaws, the cutter guide able to guide a cutter to cut in a plane parallel to the jaw motion plane.    
     
     
         15 . A patella resection guide for guiding a cutter to cut a patella having an anterior side, an opposite posterior side, and a periphery around the patella, the patella resection guide comprising: 
 a first jaw member shaped to grip said periphery of said patella;    a second jaw member shaped to grip said periphery of said patella;    a support member connecting the first jaw member in translating relationship to the second jaw member, the support constraining the jaw members to remain parallel when they move relative to one another;    a handle actuable to move the first and second jaw members in a motion plane from a first position in which the jaw members are further from one another to a second position in which the jaw members are nearer one another;    a cutter guide adjacent the jaws, the cutter guide able to guide a cutter to cut in a plane parallel to the jaw motion plane.    
     
     
         16 . A method comprising the steps of: 
 providing a patella resection guide having patella gripping jaws and a cutter guide;    making an incision on at least one of the medial and lateral sides of a knee to expose said patella from the side;    gripping the medial and lateral sides of the patella with the jaws of the patella resection guide while the patella remains in its normal orientation relative to the femur; and    guiding a cutter with the cutter guide through the incision from the side of the knee to resect the patella.    
     
     
         17 . The method of  claim 16  further comprising the steps of: 
 providing a gauge alternately connectable to a first side of the patella resection guide to indicate the amount of bone to be removed and to a second side of the patella resection guide to indicate the amount of bone to remain;  
 determining whether to gauge the amount of bone to remove or the amount of bone to remain;  
 attaching the depth gauge to the appropriate side; and  
 cutting the bone.  
 
     
     
         18 . A femoral distal cut guide for cutting a femur, the femur having a frontal plane, a sagittal plane, a femoral head adjacent a hip joint, a femoral shaft with an intramedullary canal, a condylar portion adjacent a knee joint having a medial side and a lateral side, an anatomic axis lying along the intramedullary canal, and a mechanical axis lying along a line from the center of the femoral head to the center of the knee joint, the cut guide comprising: 
 an intramedullary rod having a longitudinal rod axis; and    a distal cut guide, the distal cut guide mounted on the intramedullary rod at an angle to the longitudinal rod axis, as measured in the frontal plane, so that aligning the intramedullary rod with the anatomic axis and extending the distal cut guide toward the side of the knee orients the distal cut guide to guide a cutter from the side of the knee to cut the distal femur perpendicular to the mechanical axis.    
     
     
         19 . The femoral distal cut guide of  claim 18  further comprising an intramedullary alignment guide connected to the intramedullary rod and having a longitudinal guide axis at an angle to the longitudinal rod axis, as measured in the frontal plane, so that when the rod is aligned with the anatomic axis and the longitudinal guide axis is parallel to the frontal plane, the longitudinal guide axis is perpendicular to the femoral mechanical axis and extended toward one of the medial and lateral sides of the knee.  
     
     
         20 . The femoral distal cut guide of  claim 19  further comprising a distal cut guide mounted for motion parallel to the longitudinal guide axis with the distal cut guide directed toward one of the medial and lateral sides of the knee, the distal cut guide able to be translated along the longitudinal guide axis to a position adjacent one of the medial and lateral sides of the knee.  
     
     
         21 . The femoral distal cut guide of  claim 20  wherein the intramedullary alignment guide further includes a reference surface for contacting a distal femoral condyle to position the distal cut guide to make a cut at a predetermined distance from the femoral condyle.  
     
     
         22 . The femoral distal cut guide of  claim 20  wherein the intramedullary alignment guide further includes a reference surface for contacting said intercondylar sulcus to position the distal cut guide to make a cut at a predetermined distance from the intercondylar sulcus.  
     
     
         23 . A method of cutting a distal femur comprising the steps of: 
 providing a distal cut guide having an intramedullary rod;    making an incision on at least one of the medial and lateral sides of a knee to expose the distal femur from the side;    inserting the intramedullary rod into an intramedullary canal of the femur;    orienting the distal cut guide so that it extends toward one of the medial and lateral sides of the femur; and    guiding a cutter with the cutter guide to cut the distal femur from the side to form a planar distal surface.    
     
     
         24 . The method of  claim 23  further comprising the steps of: 
 providing an alignment guide extending at an angle to the intramedullary rod;  
 providing a distal cut guide having a cutter guide and being mounted for translation along the alignment guide; and  
 sliding the distal cut guide along the alignment guide until the distal cut guide is adjacent the side of the femur.  
 
     
     
         25 . The method of  claim 24  further comprising the steps of: 
 positioning the alignment guide so that a reference surface on the alignment guide contacts a distal femoral condyle; and  
 guiding a cutter with the distal cut guide to make a cut at a predetermined distance from the femoral condyle.  
 
     
     
         26 . The method of  claim 24  further comprising the steps of: 
 positioning the alignment guide so that a reference surface on the alignment guide contacts the intramedullary sulcus; and  
 guiding a cutter with the distal cut guide to make a cut at a predetermined distance from the intramedullary sulcus.  
 
     
     
         27 . A tibial cut guide assembly comprising: 
 a support having a longitudinal support axis;    a cross member mounted on the support, the cross member having a cross member axis perpendicular to the support axis, the cross member axis and support axis defining a guide plane, the cross member having a slope reference oriented at a predetermined slope angle relative to the guide plane;    a cut guide having a cross member engaging end and a cutter guide, the cross member engaging end being mounted on the cross member in engagement with the slope reference, the cutter guide defining a cut plane that is oriented at a predetermined slope angle relative to the guide plane as determined by the slope reference.    
     
     
         28 . The tibial cut guide assembly of  claim 27  further comprising a plurality of interchangeable cross members, each interchangeable cross member having a slope reference oriented at a different predetermined slope angle relative to the guide plane.  
     
     
         29 . The tibial cut guide assembly of  claim 27  wherein the cut guide is mounted on an arm projecting upwardly and inwardly from the cross member to position the cutter guide adjacent a tibia to be cut.  
     
     
         30 . The tibial cut guide assembly of  claim 27  wherein the cut guide is translatable along the cross member from a first position to a second position, the cutter guide defining parallel planes in the first and second position.  
     
     
         31 . The tibial cut guide assembly of  claim 30  wherein the cross member is translatable up and down along the support axis.  
     
     
         32 . The tibial cut guide assembly of  claim 27  further comprising a proximal adjustment mechanism actuable to change the spacing of a proximal end of the support and a proximal end of a tibia to change the angle of the support axis relative to a tibial axis.  
     
     
         33 . The tibial cut guide assembly of  claim 32  wherein the proximal adjustment mechanism comprises a screw threadingly engaging the support and abuttable with a proximal end of a tibia.  
     
     
         34 . A tibial cut guide assembly for cutting a proximal end of a tibia having a proximal end, a distal end, a tibial shaft, a tibial axis along the shaft, an anterior side parallel to a frontal plane, a medial side parallel to a sagittal plane, and a lateral side parallel to said sagittal plane, the tibial cut guide assembly comprising: 
 a support having a support axis, the support being mountable on said tibia with the support axis parallel to said tibial axis;    a cut guide, the cut guide being mounted on the support with the cut guide oriented to guide a cutter obliquely toward said tibia between the anterior side and one of the medial and lateral sides of said tibia to cut the proximal end of said tibia when the support is mounted on said tibia.    
     
     
         35 . The tibial cut guide assembly of  claim 34  further comprising a cross member mounted on the support connecting the support and cut guide, the cross member having a cross member axis perpendicular to the support axis, the cross member axis and support axis defining a guide plane, the guide plane being positionable parallel to the frontal plane and the tibial axis, the cross member having a slope reference oriented at a predetermined slope angle relative to the guide plane.  
     
     
         36 . The tibial cut guide assembly of  claim 35  wherein the cut guide has a cross member engaging end and a cutter guide, the cross member engaging end being mounted on the cross member in engagement with the slope reference, the cutter guide defining a cut plane that is oriented at a predetermined slope angle relative to the guide plane as determined by the slope reference, the cutter guide being translatable along the cross member from a first position to a second position, the cutter guide defining parallel planes in the first and second position.  
     
     
         37 . A tibial cut guide assembly comprising: 
 an alignment bar having a longitudinal alignment bar axis;    a boom mounted on the alignment bar, the boom having a boom axis perpendicular to the alignment bar axis, the boom axis and alignment bar axis defining a guide plane, the boom having a slope reference oriented at a predetermined slope angle relative to the guide plane;    a cut guide having a boom engaging end and a cutter guide, the boom engaging end being mounted on the boom in engagement with the boom slope reference, the cutter guide defining a cut plane that is oriented at a predetermined slope angle relative to the guide plane as determined by the boom slope reference.    
     
     
         38 . The tibial cut guide assembly of  claim 37  wherein the cut guide slidingly engages the boom so that the cut guide can slide along the boom from a first position further from the alignment bar to a second position nearer to the alignment bar while maintaining the cut plane at a constant angle to the guide plane.  
     
     
         39 . The tibial cut guide assembly of  claim 38  wherein the boom is mounted for translation along the alignment bar axis so that moving the boom along the alignment bar axis changes the level of the cut plane.  
     
     
         40 . The tibial cut guide assembly of  claim 37  further including a depth gauge, the depth gauge including a blade having a reference end, the depth gauge being mounted on the assembly with the reference end a predetermined fixed distance from the cut plane as measured along the alignment bar axis.  
     
     
         41 . The tibial cut guide assembly of  claim 37  wherein the cutter guide comprises a saw blade slot defining a plane for a saw blade.  
     
     
         42 . A method for cutting a proximal end of a tibia having a proximal end, a distal end, a tibial shaft, a tibial axis along the shaft, an anterior side parallel to a frontal plane, a medial side parallel to a sagittal plane, and a lateral side parallel to said sagittal plane, the method comprising the steps of: 
 mounting a cut guide on the tibia with the cut guide oriented to guide a cutter obliquely toward the tibia between the anterior side and one of the medial and lateral sides of the tibia; and    guiding a cutter obliquely toward the tibia with the cut guide to cut the proximal end of the tibia.    
     
     
         43 . The method of  claim 42  further comprising the steps of: 
 providing a support having a support axis;  
 mounting the support on said tibia with the support axis parallel to the tibial axis;  
 mounting the cut guide on the support.  
 
     
     
         44 . The method of  claim 43  wherein the step of mounting the support includes mounting the support on the anterior surface of the tibia.  
     
     
         45 . The method of  claim 44  further comprising the step of adjusting the cut guide mediolaterally while maintaining parallel cut planes.  
     
     
         46 . A method for cutting a proximal end of a tibia having a proximal end, a distal end, a tibial shaft, a tibial axis along the shaft, an anterior side parallel to a frontal plane, a medial side parallel to a sagittal plane, and a lateral side parallel to said sagittal plane, the method comprising the steps of: 
 providing a tibial alignment bar having an alignment bar axis and a tibial boom mounted on the alignment bar for translation along the alignment bar axis, the tibial boom having a boom axis perpendicular to the alignment bar axis, the alignment bar axis and boom axis together defining a guide plane, the boom further including a posterior slope reference defining a predetermined angle relative to the guide plane;    mounting the alignment bar on said tibia with the alignment bar axis parallel to the tibial axis;    providing a cut guide;    mounting the cut guide on the boom for translation along the boom axis and in engagement with the posterior slop reference such that the cut guide is oriented to guide a cutter obliquely toward the tibia between the anterior side and one of the medial and lateral sides of the tibia to cut a planar surface at the predetermined angle relative to the guide plane; and    guiding a cutter obliquely toward the tibia with the cut guide to cut the proximal end of the tibia.    
     
     
         47 . The method of  claim 46  further including the steps of: 
 providing a tibial alignment bar with a selection of booms having different posterior slope reference angles;  
 determining a desired slope;  
 picking a boom corresponding to the desired slope.  
 
     
     
         48 . The method of  claim 46  further comprising the step of making an incision on the at least one of the medial and lateral sides of a knee to expose the proximal tibia from the side.  
     
     
         49 . The method of  claim 48  further comprising the step of adjusting the cut guide mediolaterally to be adjacent until it is obliquely adjacent the proximal tibia.  
     
     
         50 . The method of  claim 49  further comprising the step of positioning the tibial boom along the alignment bar axis to set the depth of the tibial cut.  
     
     
         51 . The method of  claim 46  further comprising the steps of: 
 setting a proximal end of the tibial alignment bar adjacent the proximal end of the tibia at a desired mediolateral position and the distal end of the alignment bar adjacent the distal end of the tibia at a desired mediolateral position to establish mediolateral vertical reference axis relative to which the cut guide sets the varus-valgus angle;  
 independently of the mediolateral setting, setting the proximal end of the alignment bar at a desired anteroposterior position relative to the proximal end of the tibia and the distal end of the alignment bar at a desired anteroposterior position relative to the distal end of the tibia to establish an anteriorposterior vertical reference axis relative to which the cut guide sets the posterior slope;  
 adjusting the cut guide mediolaterally while maintaining parallel cut planes having the same varus-valgus angle and posterior slope;  
 adjusting the proximal distal position of the cut plane independently of mediolateral position to set the depth of cut; and  
 guiding a cutter with the cut guide to cut the tibia at the independently established depth, varus-valgus angle, and posterior slope.  
 
     
     
         52 . A guide for establishing a position reference on a distal portion of a femur having a distal end, an anterior surface, a medial side surface, a lateral side surface, posterior condyles, and anatomic landmarks, the guide comprising: 
 a base having a reference surface for engaging said distal end; and    a pin guide mounted for rotation relative to the base, the pin guide including at least one pin guide hole for guiding a reference pin to engage one of said medial and lateral side surfaces of said distal femur.    
     
     
         53 . The guide of  claim 52  wherein the pin guide has an alignment portion for aligning with anatomic landmarks on said distal femur.  
     
     
         54 . The guide of  claim 53  further comprising a foot connected to the base, the foot extending at an angle from the reference surface to engage said posterior condyles to establish a posterior size reference.  
     
     
         55 . The guide of  claim 54  further comprising a plate, the plate rotationally mounted to the base and the pin guide mounted on the plate so that as the pin guide rotates relative to the base the pin guide also rotates relative to the base.  
     
     
         56 . The guide of  claim 55  wherein the base includes a plurality of rotational alignment holes and the plate includes a plurality of alignment holes, different pairs of holes aligning at different angles of rotation between the base and plate.  
     
     
         57 . The guide of  claim 56  wherein the pin guide is mounted for translation relative to the plate so that the plate can be rotated to set the rotation of the pin guide hole relative to the base and the pin guide can be translated relative to the plate to set the spacing of the pin guide hole from the base.  
     
     
         58 . The guide of  claim 57  further including an anterior probe mounted for translation relative to the plate, the anterior probe having a probe tip for engaging said femoral anterior surface, the probe having size indicia to indicate the distance the probe is translated relative to the plate.  
     
     
         59 . The guide of  claim 58  further including a feeler gauge that indexes the translation of the pin guide relative to the plate to the translation of the probe relative to the plate so that sizing information determined by the probe is reflected in the position of the pin guide.  
     
     
         60 . The guide of  claim 59  wherein the pin guide is mounted for mediolateral translation relative to the plate so that it can be moved to a position adjacent the side of the femur.  
     
     
         61 . A guide for establishing a position reference on a distal portion of a femur having a distal end, an anterior surface, a posterior surface, a medial side surface, a lateral side surface, posterior condyles, a femoral axis, and anatomic landmarks, the guide comprising: 
 means for establishing a desired rotation angle relative to said femoral axis; and    means for establishing a desired A/P position between said anterior and posterior surfaces of said femur; and    means for establishing a datum on said distal femur that records the rotation angle and A/P position in such a way that the datum can be subsequently referenced by bone cutting guides to produce bone cuts relative to the rotation and position information.    
     
     
         62 . The guide of  claim 61  wherein the datum comprises an element selected from the group consisting of a pin, a hole, a slot, and a notch.  
     
     
         63 . The guide of  claim 61  wherein the datum is able to be referenced by subsequent instruments to establish the varus-valgus angle, external rotation, and anteroposterior position of bone cuts.  
     
     
         64 . The guide of  claim 61  wherein the means for establishing a desired rotation angle comprises a base having a reference surface for engaging said distal end of said femur and a datum guide mounted for rotation relative to the base, the datum guiding the positioning of a datum on one of said medial and lateral side surfaces of said distal femur.  
     
     
         65 . A method for establishing a position reference datum on a distal portion of a femur having an anterior surface, a posterior surface, posterior condyles, a femoral axis, medial and lateral epicondyles, and an A/P axis, the method comprising the steps of: 
 determining a desired rotation angle relative to the femoral axis;    determining a desired A/P position between the anterior and posterior surfaces of the femur;    creating a datum on the distal femur that records the rotation angle and A/P position in such a way that the datum can be subsequently referenced by bone cutting guides to produce bone cuts relative to the rotation and position information.    
     
     
         66 . The method of  claim 65  wherein the step of determining a desired rotation angle is accomplished by aligning a datum guide relative to an anatomic reference selected from the group consisting of the femoral posterior condyles, a line drawn between the medial and lateral femoral epicondyles, and a line drawn along the distal femoral A/P axis.  
     
     
         67 . The method of  claim 65  wherein the step of determining a desired A/P position comprises contacting the anterior femoral surface with a probe.  
     
     
         68 . The method of  claim 65  wherein the step of creating a datum comprises a step selected from the group consisting of drilling at least one hole, cutting at least one slot, and setting at least one pin in the femur.  
     
     
         69 . The method of  claim 65  further comprising the steps of: 
 providing a pin guide;  
 establishing the rotation by aligning the pin guide with one of the femoral posterior condyles, a line drawn between medial and lateral epicondyles, and a line drawn along the A/P axis;  
 establishing the A/P position by offsetting the pin guide from a probe in contact with the anterior surface; and  
 establishing the datum by guiding at least one pin through the pin guide and into the femur.  
 
     
     
         70 . The method of  claim 69  wherein the step of establishing the datum comprises guiding at least two pins through the pin guide and into the femur.  
     
     
         71 . The method of  claim 65  further comprising the steps of: 
 referencing the datum with a cut guide to orient the cut guide relative to the rotation angle and A/P position; and  
 guiding a cutter with the cut guide to cut the femur.  
 
     
     
         72 . The method of  claim 71  further comprising the step of making an incision on the at least one of the medial and lateral sides of a knee to expose the femur from the side and performing the other steps through the incision from the side of the knee.  
     
     
         73 . A method for establishing a position reference datum on a distal portion of a femur having a distal end, an anterior surface, a posterior surface, a medial side surface, a lateral side surface, posterior condyles, a femoral axis, and anatomic landmarks, the method comprising the steps of: 
 providing a guide having a base and a pin guide mounted for rotation and translation relative to the base;    placing the base against the distal end of said femur;    rotating the pin guide relative to the base to a desired rotation angle;    translating the pin guide relative to the base to a desired A/P position; and    inserting at least one pin into said femur with the pin guide, the at least on pin fixing the rotation angle and A/P position for future reference.    
     
     
         74 . The method of  claim 73  wherein the step of inserting at least one pin comprises inserting at least two pins.  
     
     
         75 . The method of  claim 73  further comprising the steps of: 
 mounting a cut guide on the pin to orient the cut guide at the desired rotation angle and A/P position; and  
 guiding a cutter with the cut guide to make anterior, posterior and chamfer cuts on the distal femur.  
 
     
     
         76 . The method of  claim 75  further comprising the steps of: 
 making an incision on one of the medial and lateral sides of the knee to expose the femur from the side; and  
 performing the other steps through the incision from the side of the knee.  
 
     
     
         77 . An apparatus for guiding a cutter to cut a femur having a datum established on it, the datum fixing a desired external rotation and A/P position, the apparatus comprising: 
 a cut guide for guiding a cutter to cut said femur; and    means for engaging said datum to orient the cut guide to guide a cutter to cut said femur at said desired external rotation and A/P position.    
     
     
         78 . The apparatus of  claim 77  wherein the cut guide comprises a saw blade guide.  
     
     
         79 . The apparatus of  claim 78  wherein the saw blade guide includes slots for guiding a saw blade to form anterior, posterior, and chamfer cuts on said femur.  
     
     
         80 . The apparatus of  claim 79  wherein the guide includes a side portion and a distal portion, the slots sweeping from the side portion to the distal portion to allow cutting from the side and distally.  
     
     
         81 . The apparatus of  claim 77  wherein the means for engaging said datum comprises a hole formed in the cut guide.  
     
     
         82 . A guide for guiding a cutter to cut a profile on a distal femur, the femur having at least one pin inserted into the side of the femur fixing a desired external rotation and A/P position, the guide comprising: 
 a distal portion having inner and outer distal surfaces;    a side portion having inner and outer side surfaces with at least one hole extending through the side from the inner to the outer side surface for receiving said at least one pin to set the guide at said desired external rotation and A/P position; and    a cut guide for guiding a cutter to cut said femur at said desired external rotation and A/P position.    
     
     
         83 . The guide of  claim 82  wherein the cut guide comprises a saw guide slot.  
     
     
         84 . The guide of  claim 83  wherein the saw guide slot sweeps from the side portion to the distal portion.  
     
     
         85 . The guide of  claim 82  wherein the distal portion further comprising an opening for visualizing the distal end of the femur.  
     
     
         86 . The guide of  claim 82  wherein the at least one hole is slotted so that the guide can slide between a proximal position and a distal position on the pin to permit the inner, distal guide surface to be positioned in contact with said distal femur.  
     
     
         87 . The guide of  claim 86  further comprising a distal fixation hole to receive a fastener to fix the guide in a position with the inner, distal guide surface in contact with said distal femur.  
     
     
         88 . A method for cutting a distal portion of a femur having an anterior surface, a posterior surface, and a femoral axis, the method comprising the steps of: 
 determining a desired rotation angle relative to the femoral axis;    determining a desired A/P position between the anterior and posterior surfaces of the femur;    creating a datum on the distal femur that records the rotation angle and A/P position;    referencing the datum with a cut guide to orient the cut guide relative to the rotation angle and A/P position; and    guiding a cutter with the cut guide to cut the femur.    
     
     
         89 . The method of  claim 88  wherein the cut guide comprises a saw guide slot and the step of guiding a cutter comprises guiding a saw blade.  
     
     
         90 . The method of  claim 89  wherein the saw guide slot sweeps from a side portion to distal portion and further comprising the step of guiding a saw blade through the slot from the side and moving the saw blade through the swept slot to guide the saw blade through the slot distally.  
     
     
         91 . The method of  claim 88  wherein the cut guide further includes window for viewing the distal end of the femur and further comprising the step of viewing the cutting of the distal end of the femur through the window.  
     
     
         92 . The method of  claim 88  wherein the datum is a pin and the cut guide has a hole for receiving the pin, the method further comprising the step of engaging the pin with the hole to position the cut guide.  
     
     
         93 . The method of  claim 92  wherein the hole comprises an elongated slot to permit the cut guide to slide proximally and distally on the pin, the method further comprising sliding the cut guide proximally on the pin until it abuts the distal femur.  
     
     
         94 . The method of  claim 93  wherein the cut guide further comprises a distal fixation hole, the method further comprising the step of inserting a fastener through the fixation hole to hold the cut guide against the distal femur.  
     
     
         95 . The method of  claim 88  further comprising the steps of: 
 making an incision on at least one of the medial and lateral sides of a knee to expose the femur from the side; and  
 performing the other steps through the incision from the side of the knee.  
 
     
     
         96 . A cut guide for a femur having an anterior side, a posterior side, a proximal end, and a distal end, the cut guide comprising: 
 an anterior body portion having an outer anterior surface, an inner anterior surface, and an anterior cut guide surface;    a distal body portion having an outer distal surface, an inner distal surface, and a distal cut guide surface, the distal body portion extending from the anterior body portion at an angle, the distal cut guide surface being aligned with the anterior cut guide surface; and    a cutter guidable from the distal cut guide surface to the anterior cut guide surface to cut the anterodistal aspect of said femur along an angle from posterior and distal to anterior and proximal.    
     
     
         97 . The cut guide of  claim 96  wherein the anterior cut guide surface comprises an anterior chisel guide and the posterior cut guide surface comprises a posterior chisel guide and the cutter comprises a chisel.  
     
     
         98 . The cut guide of  claim 97  wherein the anterior chisel guide comprises a slot extending from the outer anterior surface to the inner anterior surface, the distal chisel guide comprises a slot extending from the outer distal surface to the inner distal surface and the chisel comprises a cross sectional shape matching the anterior and distal chisel slots so that the chisel is insertable through the chisel slots from the distal chisel slot to the anterior chisel slot.  
     
     
         99 . The cut guide of  claim 98  wherein the slots are three sided and the chisel comprises a corresponding three sided shape.  
     
     
         100 . The cut guide of  claim 99  further comprising at least one distal drill guide hole formed through the distal body portion from the outer distal surface to the inner distal surface to guide a drill to form at least one hole in the distal end of the femur at a predetermined location relative to the slots.  
     
     
         101 . The cut guide of  claim 97  further comprising medial and lateral articular condyles having articulating surfaces formed thereon permitting trial fitting of the cut guide to simulate the fit of a corresponding femoral implant relative to the tibia.  
     
     
         102 . The cut guide of  claim 101  further comprising a patellar articular surface formed thereon permitting trial fitting of the cut guide to simulate the fit of a corresponding femoral implant relative to the patella.  
     
     
         103 . The cut guide of  claim 97  further comprising an inner box profile corresponding to the inner box profile of a femoral implant.  
     
     
         104 . A method for cutting the anterodistal aspect of a femur having an anterior side, a posterior side, a proximal end, and a distal end, the method comprising the steps of: 
 mounting a cut guide on the femur, the cut guide having a chisel guide; and    guiding a chisel with the chisel guide to cut the anterodistal aspect of the femur along an angle from posterior and distal to anterior and proximal.    
     
     
         105 . The method of  claim 104  wherein the chisel guide comprises an anterior chisel slot and a distal chisel slot and the chisel comprises a cross sectional shape matching the anterior and distal chisel slots, the method further comprising the step of inserting the chisel through the slots from the distal chisel slot to the anterior chisel slot.  
     
     
         106 . The method of  claim 105  wherein the cut guide further comprises at least one drill guide hole, the method further comprising the step of guiding a drill with the at least one drill guide hole to drill a hole in the distal end of the femur at a predetermined location relative to the slots.  
     
     
         107 . The method of  claim 104  wherein the cut guide further comprises medial and lateral articular condyles having articulating surfaces formed thereon, the method further comprising the step of performing a trial fitting of the cut guide on the femur and articulating it relative to the tibia to simulate the fit of a corresponding femoral implant relative to the tibia, before the step of guiding a chisel to cut the femur.  
     
     
         108 . The method of  claim 104  wherein the cut guide further comprises a patellar articular surface formed thereon, the method further comprising the step of performing a trial fitting of the cut guide on the femur and articulating it relative to the patella to simulate the fit of a corresponding femoral implant relative to the patella, before the step of guiding a chisel to cut the femur.  
     
     
         109 . The method of  claim 104  further comprising the steps of first making an incision on one of the medial and lateral sides of the knee joint to expose the femur from the side and performing the other steps through the incision from the side of the knee.  
     
     
         110 . The method of  claim 104  further comprising the steps of providing a femoral notch guide comprising a notch cut guide and a protrusion for engaging the cut in the anterodistal aspect of the femur, engaging the protrusion with the cut in the anterodistal aspect of the femur to align the femoral notch cut guide, and guiding a cutter with the notch cut guide to cut a notch in the femur.  
     
     
         111 . The method of  claim 106  further comprising the steps of providing a femoral notch guide comprising a notch cut guide and at least one protrusion for engaging the at least one hole drilled in the distal end of the femur, engaging the protrusion with the hole in the distal end of the femur to align the femoral notch cut guide, and guiding a cutter with the notch cut guide to cut a notch in the femur.  
     
     
         112 . A method of total knee arthroplasty comprising the steps of: 
 making an incision on at least one of the medial and lateral sides of a knee to expose the knee joint from the side;    placing a patella cut guide adjacent the patella;    guiding a cutter with the patella cut guide through the incision to cut the patella from the side of the knee;    placing a femoral cut guide adjacent the femur;    guiding a cutter with the femoral cut guide through the incision to cut the femur from the side of the knee;    placing a tibial cut guide adjacent the tibia; and    guiding a cutter with the tibial cut guide through the incision to cut the tibia from the side of the knee.    
     
     
         113 . The method of  claim 112  wherein the step of cutting the femur comprises cutting the distal end of the femur and wherein the method further comprises the steps of: 
 establishing a datum on the femur engageable from the side of the knee to fix the desired external rotation and anteroposterior position of subsequent bone cuts;  
 engaging the datum with a cut guide to orient the cut guide in the desired external rotation and anteroposterior position; and  
 cutting the distal femur profile from the side of the knee.  
 
     
     
         114 . The method of  claim 112  wherein the step of cutting the patella further comprises cutting the patella while maintaining the patella in its normal anteroposterior orientation relative to the femur.