Abstract:
A method for preparing bone to receive a prosthetic implant, according to an exemplary aspect of the present disclosure includes, among other things, positioning a bone preparation guide assembly on a bone, reaming the bone through a first cut opening of the bone preparation guide assembly, dividing the first cut opening into at least two distinct slots and making cuts in the bone through the at least two distinct slots.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Application No. 61/595,365, which was filed Feb. 6, 2012. 
    
    
     BACKGROUND 
     This disclosure relates to orthopedic surgical instrumentation, and more particularly to a surgical instrumentation set and method of use for preparing bone to receive a prosthetic implant, such as a patello-femoral implant. 
     Total or partial knee replacement surgery has been performed for many years to treat patients with diseased knee joints. One type of knee replacement surgery that may be required is patello-femoral knee replacement surgery. Patello-femoral knee replacement surgery can be required to address patello-femoral arthritis in the patella-femoral joint that extends between a femur and patella of a knee joint. 
     Numerous cuts (i.e., resections) must be made in the femur to prepare the femur for receiving a patello-femoral implant. Techniques exist for resecting the femur for this purpose. For example, some techniques require hand sculpting using osteotomes or rasps. However, these techniques are typically performed without the benefit of any guide that can be used to set the position and depth of the various cuts. Other techniques require burring, which may be relatively time consuming and also fail to provide a guide that can be used to establish cut depth and other cut parameters. 
     SUMMARY 
     A method for preparing bone to receive a prosthetic implant, according to an exemplary aspect of the present disclosure includes, among other things, positioning a bone preparation guide assembly on a bone, reaming the bone through a first cut opening of the bone preparation guide assembly, dividing the first cut opening into at least two distinct slots and making cuts in the bone through the at least two distinct slots. 
     In a further non-limiting embodiment of the foregoing method for preparing bone, the at least two distinct slots are smaller than the first cut opening. 
     In a further non limiting embodiment of either of the foregoing methods for preparing bone, the step of positioning includes aligning a distal proximal stylus within an intercondylar notch of the bone to set a distal-proximal position of the bone preparation guide assembly. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the step of aligning includes inserting a post of the distal proximal stylus through an opening in a cut guide of the bone preparation guide assembly. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the method includes reaming the bone through a second cut opening of the bone preparation guide assembly, dividing the second cut opening into at least two additional distinct slots and making cuts in the bone through the at least two additional distinct slots of the second cut opening. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the steps of making cuts through the at least two distinct slots of the first cut opening and the at least two additional distinct slots of the second cut opening are performed using the same cutting tool. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the steps of dividing the first cut opening and the second cut opening include inserting a stabilizer pin into the first cut opening and the second cut opening. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the same stabilizer pin is used during the steps of dividing. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the step of dividing the first cut opening includes inserting a stabilizer pin into the first cut opening. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the method includes the step of making an anterior cut in the bone prior to the step of positioning the bone preparation guide assembly. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the step of making the anterior cut in the bone comprises the steps of positioning an anterior cut guide assembly relative to the bone, adjusting a height of the anterior cut guide assembly, and making the anterior cut by inserting a cutting tool through a slot in the anterior cut guide assembly. 
     In a further non-limiting embodiment of any of the foregoing methods of preparing bone, the method includes the step of placing an implant thickness indicator into the slot of the anterior cut guide assembly prior to the step of adjusting the height. 
     A surgical instrumentation set, according to an exemplary aspect of the present disclosure includes, among other things, a bone preparation guide assembly that includes a first cut guide having a first cut opening and a stabilizer pin received within the first cut opening to separate the first cut opening into at least two distinct slots. 
     In a further non-limiting embodiment of the foregoing surgical instrumentation set, a cutting tool is configured to be inserted through the at least two distinct slots. 
     In a further non-limiting embodiment of either of the foregoing surgical instrumentation sets, the cutting tool is a disposable cutting tool. 
     In a further non-limiting embodiment of any of the foregoing surgical instrumentation sets, the bone preparation guide assembly includes a second cut guide connected to the first cut guide via a bridge, and the second cut guide includes a second cut opening configured to receive the stabilizer pin to separate the second cut opening into at least two additional distinct slots. 
     In a further non-limiting embodiment of any of the foregoing surgical instrumentation sets, a slot extends through the first cut guide adjacent to the first cut opening. 
     In a further non-limiting embodiment of any of the foregoing surgical instrumentation sets, a distal proximal stylus has a post configured to extend through an opening of the slot. 
     In a further non-limiting embodiment of any of the foregoing surgical instrumentation sets, an anterior cut guide assembly is configured to establish a positioning of the bone preparation guide assembly. 
     In a further non-limiting embodiment of any of the foregoing surgical instrumentation sets, the bone preparation guide assembly includes a second cut guide that extends generally perpendicular to the first cut guide. 
     The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates a knee joint having a prosthetic implant. 
         FIG. 2  illustrates an anterior cut guide assembly of a surgical instrumentation set that can be used to resect a bone to prepare the bone for receiving a prosthetic implant. 
         FIG. 3  illustrates an insert that can be used with the anterior cut guide assembly of  FIG. 2 . 
         FIGS. 4A, 4B and 4C  illustrate a bone preparation guide assembly of a surgical instrumentation set that can be used to prepare various cuts in a bone to prepare the bone for receiving a prosthetic implant. 
         FIGS. 5, 6, 7, 8A, 8B and 9  illustrate a technique for preparing bone to receive a prosthetic implant utilizing the surgical instrumentation set depicted in  FIGS. 2-4 . 
         FIG. 10  illustrates a bone that has been resected according to the technique depicted in  FIGS. 5-9 . 
         FIG. 11  illustrates an anterior cortex reference guide of a surgical instrumentation set. 
         FIGS. 12A and 12B  illustrate another exemplary anterior cut guide assembly of a surgical instrumentation set. 
         FIG. 13  illustrates an implant thickness indicator. 
         FIG. 14  illustrates another implant thickness indicator embodiment. 
         FIGS. 15A and 15B  illustrate another bone preparation guide assembly of a surgical instrumentation set. 
         FIG. 15C  illustrates a cutting tool. 
         FIG. 15D  illustrates a stabilizer pin. 
         FIG. 16  illustrates a distal proximal stylus. 
         FIGS. 17, 18, 19, 20, 21, 22A, 22B, 23A, 23B, 23C, 24A, 24B, 24C, 25, 26, 27, 28, 29, 30, 31, 32 ,  33  and  34  illustrate a technique for preparing bone to receive a prosthetic implant utilizing the surgical instrumentation set depicted in  FIGS. 11-16 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a portion of a joint  10 , such as a knee joint of the human body. In this embodiment, the joint  10  includes a femur  12 , although the joint  10  could include other or additional bones, including but not limited to a tibia and a patella (not shown). Diseased portions of the femur  12  have been removed and replaced with a prosthetic implant  14  that is positionable within the joint  10 . 
     In the exemplary embodiment, the prosthetic implant  14  is a patello-femoral implant. A patello-femoral implant is a prosthetic implant that can be used to repair the patello-femoral joint (space between the patella and a distal portion of the femur  12 ), such as to address patello-femoral arthritis and/or some other disease. Although the embodiments of this disclosure are presented in the context of implanting a patella-femoral implant, this disclosure could also extend to other implants and to other surgeries. 
       FIGS. 2-4  illustrate various orthopedic surgical instruments that can be used to prepare a bone for the implantation of a prosthetic implant  14  similar to the one illustrated by  FIG. 1 . In one exemplary embodiment, the orthopedic surgical instruments are part of a surgical instrumentation set that can be used to prepare a patient&#39;s femur, such as by sizing, positioning, marking and/or resectioning the femur to receive a patello-femoral implant. It should be understood; however, that the surgical instrumentation set illustrated herein is not limited to uses associated with a patello-femoral implant and could have additional applications related to other prosthetic implants and other surgeries. 
       FIG. 2  illustrates an anterior cut guide assembly  16  that can be used to resect bone, such as by making an anterior cut in a femur (see anterior cut C 1  in bone B 1  of  FIG. 10 , for example). As discussed in greater detail below, the anterior cut guide assembly  16  can reference an anterior cortex of the femur to control flexion/extension and can reference the posterior condyles of the femur and a longitudinal axis of the tibia to establish internal/external rotation. 
     In one exemplary embodiment, the anterior cut guide assembly  16  includes a base  18 , an anterior cortex reference guide  20  that extends from a top surface  22  of the base  18 , a posterior condyle reference guide  24  that extends from a bottom surface  26  of the base  18 , and a positioning tool  27  that is selectively engageable relative to a recess  30  of a proximal surface  32  of the base  18 . The positioning tool  27  can include a handle  28 . The base  18  further includes an arm  34  that can extend about a portion of a bone and is removably securable relative to the bone with a pin  36  or other fastener that can be received through an opening  38  of the arm  34 . The base  18  can also include one or more bone spikes  39  (one shown) that can be driven into bone to removably secure the base  18  to the bone. 
     The anterior cortex reference guide  20  includes a stylus  41  that is moveable in a direction D 1  relative to a sleeve  43  that is connected to the base  18 . The stylus  41  can be positioned to establish a desired flexion/extension angle of an anterior cut. 
     The posterior condyle reference guide  24  includes a shaft  45  that is positioned transversely relative to a rod  47  that is connected to the bottom surface  26  of the base  18 . The shaft  45  can be pivoted relative to the rod  47  to locate the posterior condyle reference guide  24  at a desired positioning relative to the condyles of the bone. 
     Additional instrumentation can be used in combination with the anterior cut guide assembly  16  to make an anterior cut in a femur for receiving a prosthetic implant.  FIG. 3  illustrates an insert  40  that is selectively engageable relative to the base  18  of the anterior cut guide assembly  16  after removal of the anterior cortex reference guide  20 . In the exemplary embodiment, the insert  40  includes a shape that corresponds to the shape of the top surface  22  of the base  18 . The insert  40  can be a magnetic insert that magnetically attaches to the top surface  22  of the base  18 , although other attachment mechanisms are contemplated. One or more insert(s)  40  can be added to the top surface  22  to establish a desired height (in millimeter increments) of a cutting surface  49  for making an anterior cut into bone. The inserts  40  can be provided in various sizes. 
     The exemplary surgical instrumentation set can further include a bone preparation guide assembly  42 , as is shown in  FIGS. 4A, 4B and 4C . The bone preparation guide assembly  42  can be used to further resect bone for implanting a prosthetic implant, such as a patello-femoral implant. The bone preparation guide assembly  42  includes a trochlear cut guide  44  (i.e., a first cut guide) and a distal cut guide  46  (i.e., a second cut guide) connected to the trochlear cut guide  44  via a bridge  48 . In the exemplary embodiment, the distal cut guide  46  extends perpendicularly relative to the trochlear cut guide  44 . The bone preparation guide assembly  42  can be mounted to bone by inserting fasteners through openings  55  of the trochlear cut guide  44  and into bone. 
     Each of the trochlear cut guide  44  and the distal cut guide  46  include cut openings  50  that can receive cutting tools  54 A,  54 B for making trochlear and distal cuts in bone. The cutting tools  54 A,  54 B could be different cutting tools or the same cutting tool. In the exemplary embodiment, each cutting tool  54 A,  54 B includes a depth control stop  57 A,  57 B, respectively, that controls the depth of the cut made through the cut openings  50 . The cut openings  50  can also include slots  52  for receiving additional cutting tools (See  FIG. 4C , for example). 
     The trochlear cut guide  44  can also include a slot  53  for making additional cuts in bone, such as with an osteotome or other cutting tool. The distal cut guide  46  may also include a depth pin  58  that establishes a depth of the bone preparation guide assembly  42  relative to an intercondylar notch  60  of a bone B 1  (See  FIG. 7 ). 
     Referring to  FIG. 4B , a trochlear stabilizer pin  62  can be inserted into the cut opening  50  of the trochlear cut guide  44  of the bone preparation guide assembly  42  to separate the cut opening  50  into the two distinct slots  52  that are smaller than the cut opening  50 . Similarly, a distal stabilizer pin  64  can be inserted into the cut opening  50  of the distal cut guide  46  of the bone preparation guide assembly  42  to separate the cut opening  50  into the two distinct slots  52 . The trochlear and distal stabilizer pins  62 ,  64  establish sizes of the slots  52  and establish a cutting angle of the cutting tools that can be used to make numerous cuts in the bone. 
     As shown in  FIG. 4C , a plurality of cutting tools  70 A,  70 B and  70 C can be used to make various cuts in bone using the bone preparation guide assembly  42 , as discussed in greater detail below. In the exemplary embodiment, the cutting tools  70 A,  70 B and  70 C are different osteotomes that can be malleted into bone, although other cutting tools are also contemplated as within the scope of this disclosure. 
     An example technique for utilizing the surgical instrumentation set illustrated by  FIGS. 2-4  to prepare a patient for receiving a prosthetic implant is described below with reference to  FIGS. 5-9 . In one exemplary embodiment, the surgical instrumentation set is used to resect bone for receiving a patello-femoral implant. The technique described with reference to  FIGS. 5-9  is but one exemplary embodiment for utilizing the surgical instrumentation set described above, and it should be understood that fewer or additional steps than recited below could be performed and that the recited order of steps is not intended to limit this disclosure. 
     As illustrated by  FIG. 5 , the technique begins by placing the anterior cut guide assembly  16  relative to a first bone B 1  (e.g., a femur) and a second bone B 2  (e.g., a tibia) of a patient. In this exemplary embodiment, the anterior cortex reference guide  20  is positioned relative to the first bone B 1  and the stylus  41  is moved in the direction D 1  (and/or swiveled in the direction D 2 ) to establish a desired flexion/extension angle F/E of an anterior cut C 1  (See  FIG. 6 ) of the first bone B 1 . The flexion/extension angle F/E refers to the angle of the anterior cut C 1  with respect to the first bone B 1 . In one exemplary embodiment, the flexion/extension angle F/E of the anterior cut C 1  is set at approximately 5° from an anterior cortex surface of the bone B 1 , although the actual setting can vary depending on the patient. 
     Next, the posterior condyle reference guide  24  can be connected to the rod  47  of the sleeve  43  and can be used to set the internal/external rotation R of the anterior cut C 1 . External rotation refers to tilting the prosthetic implant towards the lateral side of the knee. The posterior condyles are a good rotational guide in a normal healthy knee, therefore, the internal/external rotation R of the anterior cut C 1  can be referenced off of the posterior condyles of the first bone B 1  and a longitudinal axis A 1  of the second bone B 2 . In one exemplary embodiment, the internal/external rotation of the anterior cut C 1  is positioned at approximately 3° from the posterior condyles of the first bone B 1 . 
     Once the anterior cortex reference guide  20  and the posterior condyle reference guide  24  are properly positioned, these components are secured to the base  18 . The base  18  can then be secured to the first bone B 1  by malleting the base  18  such that the bone spike  39  is driven into the first bone B 1 . Alternatively, the posterior condyle reference guide  24  can be positioned after the base  18  is driven into the first bone B 1 . A pin  36  can also be malleted through the opening  38  and into the first bone B 1  to position the arm  34  and further secure the base  18 . The anterior cortex reference guide  20  is connected to the top surface  22  of the base  18  and the posterior condyle reference guide  24  is connected to a bottom surface  26  of the base  18 . 
     The positioning tool  27  can be used to as a guide to align the anterior cut guide assembly  16  relative to the first bone B 1  and the second bone B 2 . For example, the handle  28  of the positioning tool  27  can be used as a reference when viewed from a frontal view and a sagittal view to align a Q-angle and the flexion/extension of the anterior cut guide assembly  16  during set up of the anterior cut guide assembly  16 . 
     Once the anterior cut guide assembly  16  is appropriately positioned, the anterior cortex reference guide  20  and the posterior condyle reference guide  24  can be removed from the base  18 , as shown in  FIG. 6 . One or more inserts  40  can then be attached to the top surface  22  of the base  18  to establish a desired cut height CH of the anterior cut C 1 . A surgeon will select the desired cut height CH of the anterior cut C 1 . A pin  77  can optionally be used to provide additional stability to the base  18  as the anterior cut C 1  is made. Once the desired cut height CH is determined and the insert(s)  40  is positioned, a cutting tool (not shown), such as an oscillating saw or other suitable cutting tool, can make the anterior cut C 1  in the first bone B 1  by using the insert(s)  40  as a guide surface. The base  18  is removed from the bone B 1  after the anterior cut C 1  is made. 
     Referring to  FIG. 7 , the bone preparation guide assembly  42  can be positioned relative to the first bone B 1  after the base  18  of the anterior cut guide assembly  16  has been removed. In this exemplary embodiment, the trochlear cut guide  44  of the bone preparation guide assembly  42  is positioned on the anterior cut C 1 , and the distal cut guide  46  is positioned transversely to the trochlear cut guide  44  by inserting the depth pin  58  into the intercondylar notch  60  of the first bone B 1 . The surgeon performing the surgery can select the mounting location of the bone preparation guide assembly  42 . Once the bone preparation guide assembly  42  is positioned, the cutting tools  54 A,  54 B (one at a time and in any order) can be inserted through the cut openings  50  to make the trochlear and distal cuts in the first bone B 1 . The depth control stops  57 A,  57 B of the cutting tools  54 A and  54 B can be used to control the depth of the trochlear and distal cuts made through the cut openings  50 . 
     As shown in  FIGS. 8A and 8B , the trochlear stabilizer pin  62  can be inserted into the cut opening  50  of the trochlear cut guide  44  and the distal stabilizer pin  64  can be inserted into the cut opening  50  of the distal cut guide  46  after the trochlear and distal cuts have been made in the first bone B 1 . The trochlear stabilizer pin  62  and the distal stabilizer pin  64  separate each cut opening  50  into a distinct number of slots  52 . In this example, the cut openings  50  are divided into two distinct slots  52 , although additional slots could be provided. The trochlear stabilizer pin  62  and the distal stabilizer pin  64  also establish the size of each slot  52  and control the cut angle of cuts that are made through the slots  52 . 
     Referring to  FIG. 9 , various cutting tools  70 A,  70 B and  70 C can be used to make numerous additional cuts in the first bone B 1  using the slots  52  established by the trochlear stabilizer pin  62  and the distal stabilizer pin  64  and the slot  53  as cutting guides. In this exemplary embodiment, the cutting tools  70 A,  70 B and  70 C are different sized osteotomes that can be malleted into bone. Other cutting tools are also contemplated as within the scope of this disclosure. Also, in some circumstances, the same cutting tool can be used to make some or all of the cuts. Once these cuts have been made, the bone preparation guide assembly  42  can be removed from the first bone B 1  and a prosthetic implant  14  can implanted (See  FIG. 1 ). A trial implant could also be used to confirm that the various cuts are sized appropriately to accept a prosthetic implant. 
       FIG. 10  illustrates the first bone B 1  after various resections have been made using the surgical instrumentation set described above. The surgical instrumentation set can be used to create both the anterior cut C 1  and a pocket  90  in the bone B 1  for receiving a prosthetic implant  14 , such as the patello-femoral implant illustrated by  FIG. 1 . The pocket  90  is formed by making the trochlear and distal cuts through cut openings  50  and the various other cuts through the slots  52 ,  53  of the bone preparation guide assembly  42  (See  FIGS. 7-9 ). In one exemplary embodiment, the pocket  90  provides a space for receiving a distal tongue of a prosthetic implant. 
       FIGS. 11, 12A, 12B, 13, 14, 15A, 15B, 15C, 15D and 16  illustrate another surgical instrumentation set made up of multiple orthopedic surgical instruments that can be used to prepare a bone for the implantation of a prosthetic implant  14  similar to the one illustrated by  FIG. 1 . In one exemplary embodiment, the surgical instrumentation set can be used to prepare a patient&#39;s femur, such as by sizing, positioning, marking and/or resectioning the femur to receive a patello-femoral implant. The surgical instrumentation set may have additional or alternative uses within the scope of this disclosure. 
       FIG. 11  shows an anterior cortex reference guide  100  of the surgical instrumentation set. As discussed in greater detail below, the anterior cortex reference guide  100  can be used to establish a flexion/extension angle of an anterior cut to be made in bone. The anterior cortex reference guide  100  includes a stylus  102  that is moveable in a direction D relative to a guide body  104 . The stylus  102  can be positioned to establish a desired flexion/extension angle of an anterior cut. The guide body  104  can include a set screw  105  for locking a positioning of the stylus  102 . The set screw  105  can be turned to contact a rod  107  of the stylus  102  that is received within an opening  109  through the guide body  104 . 
     The guide body  104  can also include a slot  106 . A knob  108  is vertically adjustable in a direction V within the slot  106 . In one embodiment, the knob  108  slides within the slot  106 . The knob  108  may include an opening  110  for receiving another surgical instrument, such as a drill, through the knob  108 . 
       FIGS. 12A and 12B  illustrate an anterior cut guide assembly  200  of the exemplary surgical instrumentation set. The anterior cut guide assembly  200  can be used as a guide for establishing an internal/external rotation of an anterior cut and for making the anterior cut in bone. The anterior cut guide assembly  200  of this exemplary embodiment includes a base  202 , a cutting block  204  (see  FIG. 12A ) that extends from a top surface  206  of the base  202 , and an intramedullary rod  208  that can be inserted through an opening  210  of the base  202 . A post  212  secures the cutting block  204  relative to the base  202 . 
     The base  202  can include a pair of arms  214  that extend from each side of the base  202 . The base  202  is removably securable relative to a bone via one or more fasteners (not shown) that can be received through openings  216  formed through the arms  214 . The base  202  could alternatively or additionally include one or more bone spikes (not shown) that can be driven into bone to removably secure the base  202  to the bone. 
     The cutting block  204  includes one or more posts  218  that are received in openings  219  (see  FIG. 12B ) on the top surface  206  of the base  202 . A height H of the cutting block  204  is adjustable relative to the base  202  by adjusting the post  212 . The post  212  may include a knob  213  for locking a positioning of the cutting block  204  relative to the base  202 . The cutting block  204  includes one or more cutting slots  220  that can receive a cutting tool for making an anterior cut in bone. 
     In one embodiment, the intramedullary rod  208  is received through the opening  210 , which is positioned between the pair of arms  214  of the base  202 . A base  222  of the intramedullary rod  208  includes a recess  224  that can accommodate a positioning tool (see  FIG. 19 ) for establishing a desired internal/external rotation of an anterior cut, as discussed in greater detail below. 
     One embodiment of an implant thickness indicator  300  that can be used in conjunction with the anterior cut guide assembly  200  is shown in  FIG. 13 . The implant thickness indicator  300  can be used to adjust the height H of the cutting block  204  relative to the base  202 . The implant thickness indicator  300  includes a base  302  and an upper prong  304  and a lower prong  306  that extend in the same direction from the base  302 . A slot  308  extends between the upper prong  304  and the lower prong  306 . In one embodiment, the upper prong  304  has a greater length than the lower prong  306 . The lower prong  306  may be received within the cutting slots  220  of the cutting block  204 . The upper prong  304  may rest on a portion of bone as a reference point for establishing a desired height of the cutting block  204 . 
     Another implant thickness indicator  400  that can alternatively be used in conjunction with the anterior cut guide assembly  200  to adjust the height H of the cutting block  204  is illustrated in  FIG. 14 . The implant thickness indicator  400  is a two-sided indicator that includes a base  402  and a first prong  404  and a second prong  406  that extend in opposite directions from the base  402 . Each of the first prong  404  and the second prong  406  includes an upper prong  408 , a lower prong  410  and a slot  412  that extends between the upper prong  408  and the lower prong  410 . In one embodiment, the upper prongs  408  are greater in length than the lower prongs  410 . The lower prongs  410  may be received within the cutting slots  220  of the cutting block  204 . In this embodiment, the first prong  404  can be used to adjust a desired height of the cutting block  204  and the second prong  406  can be used to reference the condyle height of an implant and provide a secondary check to ensure that additional height/material are not being resected when preparing for the receipt of the implant. 
     Referring to  FIGS. 15A and 15B , a bone preparation guide assembly  500  of the surgical instrumentation set can be used to further resect bone for implanting a prosthetic implant. The bone preparation guide assembly  500  can include a proximal cut guide  502  (i.e., a first cut guide) and a distal cut guide  504  (i.e., a second cut guide) connected to the proximal cut guide  502  via a bridge  506 . In the exemplary embodiment, the distal cut guide  504  extends perpendicularly relative to the proximal cut guide  502 . The bone preparation guide assembly  500  can be mounted to bone by inserting fasteners, such as pins, through openings  508  of the proximal cut guide  502  and into bone. 
     Each of the proximal cut guide  502  and the distal cut guide  504  include cut openings  510  that can receive a cutting tool  511  (see  FIG. 15C ) for making trochlear and distal cuts in bone. The same cutting tool  511  is used to make cuts through the cut openings  510 , in this embodiment. As shown in  FIG. 15C , the cutting tool  511  can include a depth control stop  513  that controls the depth of the cut made through the cut openings  510 . The cut openings  510  of the proximal cut guide  502  and the distal cut guide  504  can also include slots  512  for receiving additional cutting tools. 
     The proximal cut guide  502  can also include a slot  514  for making additional cuts in bone, such as with an osteotome or other cutting tool. The slot  514  extends through the proximal cut guide  502  at a position offset from the cut opening  510  (in a direction toward the bridge  506 ). The slot  514  may include an opening  516  for accommodating yet another tool, such as a distal proximal stylus, as discussed in greater detail below. In one embodiment, the slot  514  and the opening  516  form a T-shape. 
     Referring to  FIG. 15D , a stabilizer pin  515  can be inserted into the cut opening  510  of the proximal cut guide  502  of the bone preparation guide assembly  500  to separate the cut opening  510  into the two distinct slots  512  that are smaller than the cut openings  510 . Similarly, the stabilizer pin  515  can be inserted into the cut opening  510  of the distal cut guide  504  of the bone preparation guide assembly  500  to separate the cut opening  50  into at least two additional distinct slots  512 . 
     The stabilizer pin  515  may include a plug portion  517  that is received within the cut openings  510  and a post portion  519  that protrudes out of the cut openings  510 . The stabilizer pin  515  establishes the sizes of the slots  512  and establishes a cutting angle of the cutting tools that can be used to make numerous cuts in the bone, such as for preparing a pocket in the bone. 
       FIG. 16  illustrates a distal proximal stylus  600  that can be used with the bone preparation guide assembly  500  to set a position of an implant in the proximal distal direction. The distal proximal stylus  600  includes a handle  602  and a post  604  that extends from the handle  602 . The post  604  of the distal proximal stylus  600  may be received through the opening  516  of the proximal cut guide  502  of the bone preparation guide assembly  500  to align the distal proximal stylus  600  within an intercondylar notch of the bone, as is discussed in more detail below. 
     An example technique for utilizing the surgical instrumentation set illustrated in  FIGS. 11 through 16  to prepare a patient for receiving a prosthetic implant is described below with reference to  FIGS. 17 through 34 . In one exemplary embodiment, the surgical instrumentation set is used to resect bone for receiving a patello-femoral implant. The technique described with reference to  FIGS. 17 through 34  is but one exemplary embodiment for utilizing the surgical instrumentation set described above, and it should be understood that fewer or additional steps than recited below could be performed and that the recited order of steps is not intended to limit this disclosure. 
     As illustrated by  FIG. 17 , the technique begins by positioning the anterior cortex reference guide  100  relative to a first bone B 1  (e.g., a femur) and a second bone B 2  (e.g., a tibia) of a patient. In this exemplary embodiment, the stylus  102  of the anterior cortex reference guide  100  is placed along a shaft S of the first bone B 1  and can be moved in the direction D to establish a desired flexion/extension angle of an anterior cut that is to be made in the first bone B 1 . The flexion/extension angle refers to the angle of the anterior cut C 1  (see  FIG. 23C ) with respect to the first bone B 1 . In one exemplary embodiment, the flexion/extension angle of the anterior cut is set at approximately 5° from an anterior cortex surface of the first bone B 1 , although the actual setting can vary depending on the patient. 
     The positioning of the knob  108  of the anterior cortex reference guide  100  can also be adjusted in the direction V within the slot  106 . In one embodiment, the knob  108  is adjusted to be approximately 1 cm above the bottom of the intercondylar notch IN of the first bone B 1 . Other positions are also contemplated and may vary from patient to patient and surgery to surgery. 
     Once the positioning of the anterior cortex reference guide  100  is achieved, a tool  999 , such as a drill, can be inserted through the opening  110  of the knob  108  to drill a hole  997  into the bone B 1  (see  FIG. 18 ). The anterior cortex reference guide  100  may be removed from the bone B 1  after preparing the hole  997 . 
     Referring to  FIGS. 19 and 20 , the technique may continue by inserting a positioning tool  27  into the recess  224  of the base  222  of the intramedullary rod  208  of the anterior cut guide assembly  200 . The intramedullary rod  208  can then be inserted through the hole  997  (see  FIG. 18 ) previously formed in the first bone B 1  to position the anterior cut guide assembly  200  relative to the first bone B 1 . The anterior cut guide assembly  200  is then adjusted to establish an internal/external rotation of an anterior cut. In one embodiment, the internal/external rotation is set at approximately 3 degrees from the posterior condyles of the first bone B 1 . 
     Once properly positioned, the anterior cut guide assembly  200  is secured to the first bone B 1 . As shown in  FIG. 21 , one or more fasteners  995  may be inserted through the openings  216  of the arms  214  of the base  202  to secure the anterior cut guide assembly  200 . 
     Next, as shown in  FIGS. 22A and 22B , the implant thickness indicator  300  (or alternatively the implant thickness indicator  400 ) can be inserted into one of the cutting slots  220  of the cutting block  204  to adjust the height of the cutting block  204 . This step ensures that the anterior cut thickness matches a thickness of the implant. In one embodiment, the height of the cutting block  204  is adjusted (e.g., by adjusting the height of the posts  212 ) until the implant thickness indicator  300 ,  400  touches a low point of the trochlear groove TG of the first bone B 1  (best illustrated in  FIG. 22B ). 
     The implant thickness indicator  300 ,  400  can be removed once a desired positioning is achieved.  FIGS. 23A, 23B and 23C  illustrate the insertion of a cutting tool  993  through the cutting slots  220  of the cutting block  204  to prepare the anterior cut C 1  in the first bone B 1 . The anterior cut guide assembly  200  can be removed once the anterior cut C 1  has been made. 
     Next, the bone preparation guide assembly  500  may be positioned on the first bone B 1  (see  FIG. 24A ). The cut openings  510  may be aligned within the surface of the anterior cut C 1  made in the prior steps. The distal proximal stylus  600  can next be used to set a position of an implant in the proximal distal direction. For example, the post  604  of the distal proximal stylus  600  may be inserted through the opening  516  of the proximal cut guide  502  of the bone preparation guide assembly  500  (see  FIG. 16  and  FIGS. 24A and 24B ) to align the distal proximal stylus  600  within an intercondylar notch of the first bone B 1 . Once a desired positioning is achieved, the bone preparation guide assembly  500  can be pinned to the first bone B 1  using fasteners  989  (see  FIG. 24C ). Next, a cutting tool, such as the cutting tool  511  shown by  FIG. 15C , can be used to ream the first bone B 1  through each of the cut openings  510  (not shown). 
     As shown in  FIGS. 25 and 26 , the stabilizer pin  515  may be inserted into the cut opening  510  of the distal cut guide  504  to divide the cut opening  510  into at least two distinct slots  512 . A cutting tool  987  (see  FIG. 26 ) can be inserted through the at least two distinct slots  512  to make additional cuts in the first bone B 1 . In one embodiment, the cutting tool  987  is a disposable tool. 
     Subsequently, the stabilizer pin  515  can be removed from the distal cut guide  504  and can be inserted into the cut opening  510  of the proximal cut guide  502 . Alternatively, the cuts can be made through the slots  512  of the proximal cut guide  502  first. In other words, the order of these cuts is not intended to be limiting. The same cutting tool  987  can be inserted through the at least two additional distinct slots  512  of the proximal cut guide  502  to make additional cuts in the first bone B 1 . These steps are schematically illustrated in  FIGS. 27 and 28 . Once all cuts are made, the bone preparation guide assembly  500  may be removed from the first bone B 1 , leaving a prepared pocket  90  for placement of an implant (see  FIG. 29 ). 
       FIGS. 30, 31, 32 and 33  illustrate additional steps that can be performed to prepare the first bone B 1  for receiving an implant. As shown in  FIG. 30 , a trial implant  950  can be positioned on the prepared surfaces of the first bone B 1 . Next, as shown in  FIG. 31 , a peg drill stabilizer  940  can be positioned over the trial implant  950 . Holes are then drilled into the first bone B 1  through openings in the peg drill stabilizer  940  (see  FIG. 32 ). The peg drill stabilizer  940  and the trial implant  950  can then be removed (see  FIG. 33 ). Finally, as shown in  FIG. 34 , a prosthetic implant  14  can be inserted into the prepared openings of the first bone B 1 . 
     Although the different non-limiting embodiments are illustrated as having specific components, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
     It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
     The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.