Customized Patient-Specific Anterior-Posterior Chamfer Blocks and Methods

Abstract

To provide an orthopedic surgical instrument comprising a metallic customized patient-specific surgical instrument.SOLUTION: The metallic customized patient-specific surgical instrument includes: a base plate sized to be positioned on a resected surface of a distal end of a patient's femur; an anterior resection guide body attached to the distal surface of the base plate and extending from the distal surface of the base plate to a free distal end; a posterior resection guide body attached to the distal surface and extending from the distal surface; and a pair of chamfer resection guide bodies attached to the distal surface and extending from the distal surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) Cross reference is made to U.S. patent application Ser. No. XX / XXX,XXX (Attorney Docket No. 265280-244164), entitled "METHOD OF DESIGNING AND MANUFACTURING LOW-PROFILE CUSTOMIZED PATIENT-SPECIFIC ORTHOPAEDIC SURGICAL INSTRUMENTS," and U.S. patent application Ser. No. XX / XXX,XXX (Attorney Docket No. 265280-244163), entitled "LOW-PROFILE CUSTOMIZED PATIENT-SPECIFIC ORTHOPAEDIC SURGICAL INSTRUMENTS," which are filed concurrently herewith and are expressly incorporated herein by reference.

[0002] FIELD OF THEINVENTION The present disclosure relates generally to orthopaedic surgical instruments, and more particularly to customized patient-specific orthopaedic surgical instruments. [Background technology]

[0003] Arthroplasty is a well-known surgical procedure in which a diseased and / or damaged natural joint is replaced with an artificial joint. For example, in a total knee arthroplasty surgical procedure, a patient's natural knee joint is partially or entirely replaced with an artificial knee joint or knee prosthesis. A typical knee prosthesis includes a tibial tray, a femoral component, and a polymer insert or bearing positioned between the tibial tray and the femoral component. In a hip replacement surgery, the patient's natural acetabulum is replaced with an artificial cup, and the patient's natural femoral head is partially or completely replaced with an artificial stem and femoral ball.

[0004] To facilitate the replacement of a natural joint with an artificial joint, orthopaedic surgeons use a variety of orthopaedic surgical instruments, such as, for example, cutting blocks, drill guides, milling guides, and other surgical instruments. Typically, the orthopaedic surgical instruments are reusable and generic to a patient, so that the same orthopaedic surgical instrument can be used on many different patients during similar orthopaedic surgical procedures.

[0005] Orthopedic surgical instruments can also be customized for a particular patient. Such "customized patient-specific orthopedic instruments" are disposable surgical tools used by a surgeon in performing an orthopedic surgical procedure that is intended and configured for use with a particular patient. It should be understood that these instruments are different from standard orthopedic surgical instruments that are not patient-specific and are intended for use with a variety of different patients. These customized patient-specific orthopedic instruments are different from orthopedic prostheses, whether patient-specific or generic, that are surgically implanted within a patient's body. Rather, customized patient-specific orthopedic instruments are used by an orthopedic surgeon to assist in the implantation of an orthopedic prosthesis. Summary of the Invention [Means for solving the problem]

[0006] According to one aspect of the present disclosure, an orthopaedic surgical instrument is disclosed. The instrument comprises a metallic customized patient-specific surgical instrument comprising a base plate sized to be placed on a resected surface of a distal end of a patient's femur. The base plate has a bone-facing surface, a distal surface disposed opposite the bone-facing surface, and an outer wall extending between the bone-facing surface and the distal surface. The metallic customized patient-specific surgical instrument also comprises an anterior resection guide attached to the distal surface and extending from the distal surface to a free distal end. The anterior resection guide includes an anterior cutting guide slot sized to receive a cutting saw blade. A posterior resection guide is attached to the distal surface and extends from the distal surface to a free distal end, and the posterior resection guide includes a posterior cutting guide slot sized to receive a cutting saw blade. The metallic customized patient-specific surgical instrument also comprises a pair of chamfered resection guides attached to the distal surface and extending from the distal surface. Each chamfer resection guide includes a chamfer cutting guide slot sized to receive a cutting saw blade, with each chamfer cutting guide slot extending obliquely relative to the other cutting guide slot.

[0007] In some embodiments, the metallic customized patient-specific surgical instrument can further include a boss attached to the distal surface and extending therefrom to a free distal end spaced from the free distal end of the body. The boss can include an opening defined in its free distal end, and the drill guide slot can extend from the opening in the boss through a second opening defined in the bone-facing surface. The drill guide slot can be sized to receive a surgical drill.

[0008] In some embodiments, the bone-facing surface can include a customized, patient-specific periphery shaped to match the periphery of the resected surface of the distal end of the patient's femur.

[0009] Further, in some embodiments, the metallic customized patient-specific surgical instrument can include an upper notch defined by a section of the outer edge, and the anterior cutting guide slot can open into the upper notch.

[0010] In some embodiments, the metallic customized patient-specific surgical instrument can include a lower notch defined by a section of the outer edge, and the posterior cutting guide slot can open into the lower notch.

[0011] In some embodiments, a metallic customized patient-specific surgical instrument may include multiple laminations of metallic material.

[0012] According to another aspect, a method of performing an orthopaedic surgical procedure includes aligning a customized patient-specific surgical instrument with a resected distal surface of a patient's bone, placing the customized patient-specific surgical instrument in contact with the resected distal surface, rotating the customized patient-specific surgical instrument over the resected distal surface to align an outer periphery of the resected distal surface with a customized patient-specific outer edge of a bone-facing surface of the customized patient-specific surgical instrument, and inserting a cutting saw through a cutting guide slot defined in the customized patient-specific surgical instrument to resect the patient's bone.

[0013] In some embodiments, the customized patient-specific surgical instrument used in the methods includes an anterior cutting guide slot, a posterior cutting guide slot, and a pair of chamfered cutting guide slots.

[0014] According to another aspect, an orthopaedic surgical instrument includes a metallic customized patient-specific surgical instrument including a base plate sized to be placed on a resected surface of a distal end of a patient's femur. The base plate has a bone-facing surface, a distal surface disposed opposite the bone-facing surface, and an outer wall extending between the bone-facing surface and the distal surface. The metallic customized patient-specific surgical instrument includes a body attached to the distal surface and extending from the distal surface to a free distal end, the body including an elongated opening defined in the free distal end. A cutting guide slot extends from the opening of the body through a first opening defined in the bone-facing surface, the cutting guide slot being sized to receive a cutting saw blade. A boss is attached to the distal surface and extends from the distal surface to a free distal end spaced from the free distal end of the body. The boss includes an opening defined in the free distal end. The metallic customized patient-specific surgical instrument also includes a drill guide slot extending from the opening in the boss through a second opening defined in the bone-facing surface, the drill guide slot being sized to receive a surgical drill.

[0015] In some embodiments, the bone-facing surface can include a customized, patient-specific periphery shaped to match the periphery of the resected surface of the distal end of the patient's femur.

[0016] Additionally, in some embodiments, the metallic customized patient-specific surgical instrument can include a notch defined by an outer edge section, and the cutting guide slot can open into the notch. In some embodiments, the outer edge section can be an upper section, such that a notch is defined in an upper end of the metallic customized patient-specific surgical instrument.

[0017] In some embodiments, the peripheral section may be a lower section such that a notch is defined in the lower end of the metallic customized patient-specific surgical instrument.

[0018] In some embodiments, the body may be a first body, the cutting guide may be a first cutting guide, and the metallic customized patient-specific surgical instrument may further comprise a second body attached to the distal surface and extending from the distal surface to a distal end spaced from the distal end of the first body and the boss. The second body may include an elongated opening defined in its distal end. The second cutting guide slot may extend from the opening in the second body through a third opening defined in the bone-facing surface. The second cutting guide slot may be sized to receive a cutting saw blade.

[0019] In some embodiments, the first cutting guide may define a first cutting surface and the second cutting guide may define a second cutting surface that is angled relative to the first cutting surface. Additionally, in some embodiments, the metallic customized patient-specific surgical instrument may further comprise a third body attached to the distal surface and extending from the distal surface to a distal end attached to the distal end of the second body. The third body may include an elongated opening defined in its distal end. A third cutting guide slot may extend from the opening in the third body through a fourth opening defined in the bone-facing surface. The third cutting guide slot may be sized to receive a cutting saw blade and may intersect with the second cutting guide slot.

[0020] In some embodiments, the third cutting guide can define a third cutting surface that is angled relative to the first cutting surface and the second cutting surface. Further, in some embodiments, a passage can be defined between a surface of the second body, a surface of the third body, and a distal surface of the base plate.

[0021] In some embodiments, the metallic customized patient-specific surgical instrument can further comprise a fourth body attached to the distal surface and extending from the distal surface to a free distal end spaced from the distal ends of the first body, the second body, and the third body. The fourth body can include an elongated opening defined in its distal end, and a fourth cutting guide slot can extend from the opening of the fourth body through a fifth opening defined in the bone-facing surface. The fourth cutting guide slot can be sized to receive a cutting saw blade and can intersect the second cutting guide slot.

[0022] In some embodiments, a metallic customized patient-specific surgical instrument may include multiple laminations of metallic material.

[0023] It should also be appreciated that in some embodiments, the metallic customized patient-specific surgical instrument comprises a base plate sized to be placed on the resected surface of the distal end of the patient's femur. The base plate has a bone-facing surface, a distal surface disposed opposite the bone-facing surface, and an outer wall extending between the bone-facing surface and the distal surface. The metallic customized patient-specific surgical instrument also comprises an anterior resection guide attached to the distal surface and extending from the distal surface to a free distal end. The anterior resection guide includes an anterior cutting guide slot sized to receive a cutting saw blade. The posterior resection guide is attached to the distal surface and extends from the distal surface to a free distal end, and the posterior resection guide includes a posterior cutting guide slot sized to receive a cutting saw blade. The metallic customized patient-specific surgical instrument also comprises a pair of chamfered resection guides attached to the distal surface and extending from the distal surface. Each chamfer resection guide includes a chamfer cutting guide slot sized to receive a cutting saw blade, with each chamfer cutting guide slot extending obliquely relative to the other cutting guide slot.

[0024] In some embodiments, the metallic customized patient-specific surgical instrument can further include a boss attached to the distal surface and extending therefrom to a free distal end spaced from the free distal end of the body. The boss can include an opening defined in its free distal end, and the drill guide slot can extend from the opening in the boss through a second opening defined in the bone-facing surface. The drill guide slot can be sized to receive a surgical drill.

[0025] In some embodiments, the bone-facing surface can include a customized, patient-specific periphery shaped to match the periphery of the resected surface of the distal end of the patient's femur.

[0026] Further, in some embodiments, the metallic customized patient-specific surgical instrument can include an upper notch defined by a section of the outer edge, and the anterior cutting guide slot can open into the upper notch.

[0027] In some embodiments, the metallic customized patient-specific surgical instrument can include a lower notch defined by a section of the outer edge, and the posterior cutting guide slot can open into the lower notch.

[0028] In some embodiments, a metallic customized patient-specific surgical instrument may include multiple laminations of metallic material.

[0029] It should also be appreciated that in some embodiments, a method of performing an orthopaedic surgical procedure includes aligning a customized patient-specific surgical instrument with the resected distal surface of a patient's bone, placing the customized patient-specific surgical instrument in contact with the resected distal surface, rotating the customized patient-specific surgical instrument over the resected distal surface to align an outer periphery of the resected distal surface with a customized patient-specific outer edge of the bone-facing surface of the customized patient-specific surgical instrument, and inserting a cutting saw through a cutting guide slot defined in the customized patient-specific surgical instrument to resect the patient's bone.

[0030] In some embodiments, the customized patient-specific surgical instrument used in the methods includes an anterior cutting guide slot, a posterior cutting guide slot, and a pair of chamfered cutting guide slots. [Brief description of the drawings]

[0031] The detailed description makes specific reference to the following drawings: [Figure 1] FIG. 1 is a perspective view of a customized patient-specific orthopaedic femoral cutting block. [Diagram 2] FIG. 2 is a rear side view of the cutting block of FIG. 1. [Diagram 3] FIG. 2 is a front side view of the cutting block of FIG. 1. [Figure 4] FIG. 2 is a proximal plan view of the cutting block of FIG. 1. [Diagram 5] FIG. 2 is a distal plan view of the cutting block of FIG. 1. [Figure 6] 2 is a side view of the cutting block of FIG. 1 positioned against the distal end of a patient's femur. [Figure 7] 2 is another side view of the cutting block of FIG. 1 positioned against the distal end of a patient's femur. [Figure 8] FIG. 8 is a cross-sectional elevation view taken along line 8-8 of FIG. 3. [Figure 9] FIG. 2 is a side view of a guide pin body of the cutting block of FIG. 1; [Figure 10]FIG. 10 is a distal plan view of the guide pin body of FIG. [Figure 11A] FIG. 2 is a simplified flow diagram of a process for designing and fabricating the cutting block of FIG. [Figure 11B] FIG. 2 is a simplified flow diagram of a process for designing and fabricating the cutting block of FIG. [Figure 12] FIG. 12 illustrates some steps of the process outlined in FIG. [Figure 13] FIG. 12 illustrates some steps of the process outlined in FIG. [Figure 14] FIG. 12 illustrates some steps of the process outlined in FIG. [Figure 15] FIG. 12 illustrates some steps of the process outlined in FIG. [Figure 16] FIG. 1 is a perspective view of a customized patient-specific orthopaedic tibial cutting block. [Figure 17] FIG. 17 is a rear side view of the cutting block of FIG. [Figure 18] FIG. 17 is a front side view of the cutting block of FIG. [Figure 19] FIG. 17 is a distal plan view of the cutting block of FIG. [Figure 20] FIG. 17 is a proximal plan view of the cutting block of FIG. [Figure 21] FIG. 17 is a side view of the cutting block of FIG. [Figure 22] FIG. 17 is another side view of the cutting block of FIG. [Diagram 23] FIG. 1 is a perspective view of a customized patient-specific orthopaedic femoral cutting guide. [Figure 24] FIG. 24 is a distal plan view of the femoral cutting guide of FIG. 23. [Diagram 25] FIG. 24 is a proximal plan view of the femoral cutting guide of FIG. 23. [Figure 26] FIG. 24 is a side view of the femoral cutting guide of FIG. 23. [Figure 27] FIG. 27 is a cross-sectional elevation view taken along line 27-27 and FIG. [Figure 28]FIG. 24 is a perspective view of the femoral cutting guide of FIG. 23 aligned with the resected distal end of a patient's femur. [Figure 29] FIG. 24 is an elevational view showing the femoral cutting guide of FIG. 23 sized and shaped to match the resected distal end of a patient's femur. [Diagram 30] FIG. 24 is a perspective view of the femoral cutting guide of FIG. 23 positioned on the resected distal end of a patient's femur. [Diagram 31] FIG. 13 is another embodiment of a customized patient-specific femoral cutting block. [Diagram 32] FIG. 13 is another embodiment of a customized patient-specific femoral cutting block. [Diagram 33] FIG. 13 is another embodiment of a customized patient-specific femoral cutting block. [Diagram 34] FIG. 13 is another embodiment of a customized patient-specific femoral cutting block. [Diagram 35] FIG. 13 is another embodiment of a customized patient-specific femoral cutting block. [Diagram 36] FIG. 13 is another embodiment of a customized patient-specific femoral cutting block. [Figure 37] FIG. 13 is another embodiment of a customized patient-specific femoral cutting block. [Figure 38] FIG. 13 is a perspective view of another embodiment of a customized patient-specific femoral cutting block. [Figure 39] FIG. 13 is another embodiment of a customized patient-specific femoral cutting block. [Diagram 40] FIG. 13 is a perspective view of another embodiment of a customized patient-specific femoral cutting block. [Diagram 41] FIG. 13 is a perspective view of another embodiment of a customized patient-specific femoral cutting block. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof are shown by way of example in the drawings and are herein described in detail, it being understood, however, that there is no intention to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

[0033] References herein to "one embodiment," "embodiment," "exemplary example," and the like indicate that the embodiment being described may include a particular feature, structure, or feature, but not all embodiments necessarily include that particular feature, structure, or feature. Moreover, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular element, structure, or feature is described in connection with one embodiment, it is believed to be within the knowledge of one of ordinary skill in the art to implement such element, structure, or feature in connection with other embodiments, whether or not expressly stated.

[0034] 1-10, a customized patient-specific orthopedic instrument 10 is shown. What is meant herein by the term "customized patient-specific orthopedic instrument" is a surgical tool intended and configured for use with a particular patient and used by a surgeon in the performance of an orthopedic surgical procedure. Thus, as used herein, it should be understood that the term "customized patient-specific orthopedic instrument" is distinguished from standard orthopedic surgical instruments that are intended for use with a variety of different patients and are not made or customized for any particular patient (i.e., "generic instruments," such as generic cutting blocks). Furthermore, as used herein, it should be understood that the term "customized patient-specific orthopedic instrument" is distinguished from orthopedic prostheses or implants, whether patient-specific or generic, that are surgically implanted within a patient's body. Rather, orthopedic surgeons use customized patient-specific orthopedic instruments to assist in the implantation of orthopedic prostheses. Examples of "customized patient-specific orthopaedic instruments" include customized patient-specific drill / pin guides, customized patient-specific tibial cutting blocks, customized patient-specific femoral cutting blocks, and customized patient-specific alignment guides. The surgical instrument 10 shown in Figures 1-10 is one embodiment of a customized patient-specific femoral cutting block that includes cutting guide slots 12 positioned to guide a customized patient-specific resection of a distal end 14 (see Figures 6, 7) of a patient's femur 16 along a predetermined resection plane. As described in more detail below, the femoral cutting block 10 is configured to couple to the patient's femur 16 in a unique, predetermined location and orientation. In an exemplary embodiment, the structure of the cutting block 10 is contoured to reduce size as compared to conventional cutting blocks and to avoid contact with undesired areas of the patient's bone.

[0035] As shown in FIG. 1 , the femoral cutting block 10 includes a base plate 20 and a number of surgical tool guide bodies 22 attached to and extending outward from the base plate 20. In an exemplary embodiment, the femoral cutting block 10 is a single monolithic component formed from a metallic material, such as, for example, stainless steel. As such, the base plate 20 and the guide bodies 22 form a single monolithic metallic block. As described in more detail below, the femoral cutting block 10 is formed by direct metal laser sintering (DMLS), also known as selective laser sintering (SLS), which is a form of 3-D printing technology. In DMLS, the femoral cutting block 10 is formed layer by layer using laser sintering, where light melts metal powder and forms the metallic structure that defines the femoral cutting block 10. It should be understood that other forms of 3-D printing technology, such as, for example, stereolithography, photosolidification, or resin printing, may be used to fabricate the femoral cutting block 10.

[0036] The base plate 20 includes a pair of arms 24, 26 configured to engage the distal end 14 of the patient's femur 16. The arms 24, 26 are spaced apart from one another such that a notch 28 is defined between inner edges of the arms 24, 26. The notch 28 is sized and shaped to correspond to a natural intercondylar notch 30 (see FIG. 12 ) of the patient's femur 16 defined between natural condyles 32, 34 of the patient's femur. In this manner, contact within the bone surface with the natural intercondylar notch 30, which can be difficult to model, is avoided.

[0037] As shown in Figures 1-4, each of the arms 24, 26 has a bone-contacting or bone-facing surface 36 that engages one of the natural condyles 32, 34. In an exemplary embodiment, each bone-facing surface 36 includes a number of negative contours 38 configured to receive a portion of the natural condyle 32, 34. For example, as shown in Figures 2, 4, and 6-8, each contour 38 has a unique set of ridges 40 and depressions 42 shaped to engage a corresponding unique set of depressions 44 and ridges 46 of the natural condyle 32, 34. Each of the arms 24, 26 also includes an outer surface 48 disposed opposite the corresponding bone-facing surface 36. In an exemplary embodiment, each outer surface 48 is substantially smooth. As used herein, the term "substantially" should be understood to refer to allowing for normal tolerances resulting from manufacturing variations and other design criteria. Thus, a "substantially smooth surface" is one that is smooth within normal tolerances caused or allowed by manufacturing variations and other design criteria.

[0038] As shown in FIG. 1 , the base plate 20 also includes an anterior flange 50 configured to engage the distal end 14 of the patient's femur 16. The anterior flange 50 includes a bone-facing surface 52 including a number of negative contours 54 configured to receive a portion of the patient's femur 16. For example, as shown in FIGS. 2 , 4 and 8 , the contour 54 of the anterior flange 50 has a unique set of ridges 56 and depressions 58 shaped to engage a corresponding unique set of depressions 60 and protuberances 62 of the patient's femur 16. The anterior flange 50 also includes an outer surface 64 disposed opposite the bone-facing surface 52. In the illustrative embodiment, the outer surface 64 is substantially smooth.

[0039] The negative contour 38, 54 of the base plate 20 allows the cutting block 10 (and therefore the tool guide body) to be positioned in a unique, predetermined location and orientation on the patient's femur 16. As shown in Figures 4 and 6-8, the bone-facing surface 52 defines a portion of the contour 54 and includes a pair of curved rear edges 66, 68 shaped to match a portion of the patient's femur. As a result, each of the edges 66, 68 includes a convex portion and a concave portion for receiving a corresponding concave portion and convex portion of the patient's femur. The edges 66 include a rear tip 69 sized and shaped to be positioned within the patient's natural trochlear groove 166.

[0040] The base plate 20 also includes a number of customized cavities 70 that are sized to be placed over areas of the bone at a predetermined location that may contain defects or are damaged or difficult to model. In that way, the cavities 70 may be sized to avoid contact with those areas and not impede placement of the cutting block 10 at a predetermined location and orientation. In an exemplary embodiment, the notch 28 defined between the arms 24 and 26 is one of the customized cavities. As shown in FIGS. 1-3, the customized cavity 70 also includes an opening 72 that extends through the bone-facing surface 52 of the anterior flange 50. As shown in FIG. 2, the customized cavity 70 also includes a pair of channels 74, 76 defined in the bone-facing surface 52 of the anterior flange 50. In an exemplary embodiment, each channel 74, 76 extends from an end 78 that opens into the opening 72 to an open end 80 defined at the outer edge of the anterior flange 50.

[0041] In the illustrative embodiment, the base plate 20 of the cutting block 10 is low profile to reduce the size of the incision and the amount of bone displacement required to place the cutting block 10. The low profile is customized for the block 10 by minimizing the thickness of the arms 24, 26 and the anterior flange 50. As shown in FIG. 3, a thickness 82 is defined between the outer surface 48 of each arm and the bone-facing surface 36. To minimize the thickness 82, the outer surface 48 of each arm is convexly curved to follow the concave curvature of the bone-facing surface 36. Similarly, as shown in FIG. 4, a thickness 84 is defined between the outer surface 64 and the bone-facing surface 52 of the anterior flange 50, and the outer surface 64 of the flange 50 is shaped to follow the geometry of the bone-facing surface 52 to minimize the thickness 84.

[0042] As shown in FIGS. 1-8 , each of the surgical tool guide bodies 22 of the cutting block 10 is attached to the outer surfaces 48, 64 of the arms 24, 26 and extends outwardly from the outer surfaces 48, 64 and the forward flange 50 to a free end 90 spaced from the base plate 20. In the illustrative embodiment, the guide bodies 22 include a forward guide body 100 that extends forwardly from the forward ends of the arms 24, 26 and the forward flange 50 to its free end 102. The forward guide body 100 includes a distal flange 104 and a pair of bosses 106, 108 that extend proximally from the flange 104. As shown in FIG. 1 , the opening 72 defined in the base plate 20 is disposed proximal to the distal flange 104 and between the bosses 106 and 108.

[0043] The distal flange 104 of the anterior guide body 100 includes an elongated opening 110 defined in the free end 102 and a number of interior walls 112 extending inwardly from the opening 110. As shown in FIG. 2, the interior wall 112 extends to another opening 114 defined in the bone-facing surface 52. As shown in FIGS. 4 and 6-8, the opening 114 extends through the contour 54 of the base plate 20 such that the opening 114 is defined by the edges 66, 68 of the bone-facing surface 52 that follow a curved, irregular path that matches the shape of the patient's femur 16 in that region. The opening 114 cooperates with the interior wall 112 and the elongated opening 110 to define a guide slot 12 that is sized and shaped to guide a surgical tool, such as, for example, a cutting blade, into engagement with the patient's bone. As discussed above, the cutting guide slot 12 is positioned to guide a customized, patient-specific resection of the distal end 14 of the patient's femur 16. Edge 66 conforms to the shape of the patient's femur, and the posterior tip of edge 66 extends into the patient's trochlear groove so that cutting guide slot 12 provides support for the cutting blade adjacent the area under resection.

[0044] As shown in FIG. 1, each of the bosses 106, 108 extends from a proximal surface 116 of the distal flange 104 to a curved proximal end 118. It should be understood that in other embodiments, one or both of the bosses 106, 108 may be spaced from the distal flange 104, thereby forming separate guide bodies. An opening 120 is defined in the free end 102 of each of the bosses 106, 108 adjacent the proximal end 118. An inner wall 122 extends inwardly from the opening 120. As shown in FIG. 2, each inner wall 122 extends to another opening 124 that opens into one of the channels 74, 76 to define a guide slot 126 that extends through the cutting block 10. In the exemplary embodiment, each guide slot 126 is a drill guide and fixation pin guide hole, sized and shaped to guide a surgical drill and prepare the patient's bone to receive a fixation pin for coupling the block 10 to the bone.

[0045] 9-10, the guide body 22 includes a pair of rearward guide bosses 140 attached to and extending distally from the outer surfaces 48 of the arms 24, 26, respectively. Each rearward guide boss 140 includes a guide slot 142 sized and shaped to guide surgical drills and fixation pins into engagement with the patient's bone for connecting the block 10 to the bone. Each guide boss 140 includes a post 144 extending from a base 146 attached to the outer surface 48 of one of the arms 24, 26 to a free end 148 spaced from the outer surface 48.

[0046] 9 and 10, the base 146 is wider in the anterior-posterior direction than the free end 148. Each post 144 also includes a convex, curved rear surface 150 that extends substantially perpendicular to the arm outer surface 48. In an exemplary embodiment, each post 144 also includes a curved, tapered front surface 152 that extends at an angle relative to the arm outer surface 48. The curved, tapered front surface 152 improves the manufacturability of the cutting block 10 by eliminating a flat, horizontal surface that faces downwardly and requires support structure during fabrication.

[0047] Returning to FIG. 8 , an opening 154 is defined in the free end 148 of each boss 140. An inner wall 156 extends inwardly from the opening 154 to another opening 158 defined in the bone-facing surface 36 of one of the arms 24, 26. The openings 154, 158 and the inner wall 156 cooperate to define a guide slot 142. As mentioned above, each guide slot 142 is a drill guide and fixation pin guide hole that is sized and shaped to guide a surgical drill or a self-drilling fixation pin to prepare the patient's bone to receive the fixation pin for connecting the block 10 to the bone.

[0048] 8, the interior walls 112, 122, 156 define multiple relief sections 160, 162, 164, respectively, within the guide slots 12, 126, 142 of the cutting block 10. Each of the leaf sections 160, 162, 164 is larger (e.g., wider) than the remaining guide slots 12, 126, 142 to improve manufacturability.

[0049] 11, a routine 200 for fabricating a customized patient-specific orthopaedic surgical instrument 10 is illustrated. The method 200 includes process steps 212 and 214 in which an orthopaedic surgeon performs pre-operative planning of an orthopaedic surgical procedure to be performed on a patient. Process steps 212 and 214 may be performed in any order or simultaneously with one another. In process step 212, multiple medical images of relevant portions of the patient's bones are generated. For example, in the case of a knee replacement surgery, the medical images may include an image of the distal end of the patient's femur and a proximal end of the patient's tibia. In the case of a hip replacement surgery, the medical images may include an image of the patient's acetabulum and surrounding bony anatomy, as well as an image of the proximal end of the patient's femur. To do this, the orthopaedic surgeon or other healthcare provider may operate an imaging system to generate the medical images. The medical images may be embodied as any number and type of medical images that may be used to generate a three-dimensional representational model of the patient's acetabulum and surrounding bony anatomy. For example, the medical images may be embodied as any number of computed tomography (CT) images, magnetic resonance imaging (MRI) images, or other three-dimensional medical images. Additionally, or alternatively, as described in more detail below with respect to process step 216, the medical images may be embodied as a number of x-ray images or other two-dimensional images from which a three-dimensional representation model of the relevant region of the patient's bone is derived.

[0050] In process step 214, the orthopaedic surgeon may determine any additional pre-operative constraint data. The constraint data may be based on the orthopaedic surgeon's preferences, the patient's preferences, the patient's anatomy, guidelines established by medical institutions, etc. For example, in a knee replacement surgery, the constraint data may include the type and size of the knee prosthesis, the amount of distal and posterior resection to be performed on the patient's femur, etc. In a hip replacement surgery, the constraint data may include the orthopaedic surgeon's preferences for the amount of inclination and version of the acetabular prosthesis, the amount of bone to be reamed, the size range of the orthopaedic implant, etc. In some embodiments, the orthopaedic surgeon's preferences are saved as a surgeon's profile, which may be used as the default constraint values ​​for further surgical planning.

[0051] The medical images and constraint data, if any, may be transmitted or otherwise provided to an orthopaedic surgical instrument vendor or manufacturer for processing the images. The orthopaedic surgical instrument vendor or manufacturer processes the medical images in step 216 to facilitate determination of the appropriate resection plane, instrument position, implant sizing, and fabrication of a customized patient-specific orthopaedic surgical instrument, as described in more detail below. The images may also be processed on-site, for example at a hospital or surgeon's office.

[0052] In process step 218, a three-dimensional image may be converted or otherwise generated from the medical image. For example, in embodiments where the medical image is embodied as multiple two-dimensional images, one skilled in the art may use appropriate computer algorithms to generate one or more three-dimensional images that form the multiple two-dimensional images. Furthermore, in some embodiments, the medical image may be generated based on an established standard, such as, for example, the Digital Imaging and Communications in Medicine (DICOM) standard. In such embodiments, edge detection, thresholding, watershed, or shape matching algorithms may be used to convert or reconstruct the image into a format acceptable for computer-aided design or other image processing applications.

[0053] In process step 220, the medical images and / or the transformed / reconstructed images from process step 218 may be processed to determine certain aspects related to the patient's bone anatomy, such as the anatomical axes of the patient's bones, the mechanical axes of the patient's bones, other axes and various landmarks, and / or other anatomical aspects of the patient's bones. Any suitable algorithm may be used to process the images. In some embodiments, a three-dimensional model of the patient's bones may be generated from the processed images, including a three-dimensional representation of the bones. One such three-dimensional bone model is femur model 170, shown in FIGS. 12-15 and referenced below.

[0054] In process step 222, a surgeon, vendor, or other user may identify one or more problem areas of the bone to avoid the use of a three-dimensional model. Such areas may include bone spurs, damaged areas of the bone, undercuts that may cause instruments to get stuck on the bone, or other areas that are known to be difficult to model based on medical images. One such area may include a portion of the patient's trochlear groove. As shown in FIG. 12, a user may use a femur model 170 to describe the outer edge 172 of one such area 174 on the distal end 14 of the patient's femur 16. The user may also create a raised or offset surface 176 in the outer edge 172 to define a desired location for an orthopaedic surgical instrument cavity 70.

[0055] The routine 200 may proceed to process step 224 where an outer boundary 178 of the patient-specific orthopaedic surgical instrument is defined on the femur model 170. As shown in FIGURE 13, the outer boundary 178 defines the outer edge of the planned surgical instrument, which may be, for example, the femoral cutting block 10 described above. The boundary 178 identifies the location and shape of the anterior flange 50 of the base plate 20 of the cutting block 10, as well as the location and shape of the arms 24, 26.

[0056] In process step 226, a model of the customized patient-specific orthopaedic surgical instrument is generated. In some embodiments, the model is embodied as a three-dimensional representation of the customized patient-specific orthopaedic surgical instrument. In other embodiments, the model may be embodied as a mock-up or rapid prototype of the customized patient-specific orthopaedic surgical instrument. The patient-specific orthopaedic instrument that is modeled and fabricated may be determined based on the orthopaedic surgical procedure to be performed, the constraint data, and / or the type of orthopaedic prosthesis to be implanted in the patient.

[0057] The particular shape of the customized patient-specific orthopaedic surgical instrument is determined based on the planned position and implantation angle of the orthopaedic prosthesis relative to the patient's bones. Further, the planned position of the orthopaedic surgical instrument can be based on identified landmarks of the patient's bones identified in process step 220.

[0058] In some embodiments, the particular shape and structure of the customized patient-specific orthopaedic surgical instrument may be determined based on the planned location of the instrument relative to the patient's bony anatomy. That is, the customized patient-specific orthopaedic surgical instrument may include a bone-facing surface having a negative contour that matches a corresponding contour of a portion of the patient's bony anatomy such that the orthopaedic surgical instrument may be coupled to the patient's bony anatomy at a unique location corresponding to the predetermined planned location of the instrument. Such a negative contour may include a unique set of ridges and depressions shaped to match a corresponding set of ridges and depressions on the patient's bone. When the orthopaedic surgical instrument is coupled to the patient's bony anatomy at the unique location, one or more guides (e.g., cutting or drill guides) of the orthopaedic surgical instrument may be aligned with the beveled and version surfaces as described above.

[0059] Process sub-steps 228-234 shown in FIGURE 11 outline an exemplary subroutine that may be followed to generate a model of a patient-specific orthopaedic surgical instrument. In process sub-step 228, the femur model 170 may be used to generate a customized patient-specific negative contour or contour of the patient-specific surgical instrument. To do so, a user may create a very thin sheet 180 within boundary 178 shown in FIGURE 13. The thin sheet 180 may include depressions and ridges that fall within the negative contour of the patient-specific surgical instrument.

[0060] In process sub-step 230, the user can add thickness to the sheet 180 within the boundary 178 to generate the outer surface of the customized patient-specific surgical instrument, thereby defining the base plate of the instrument. As described above, the user can minimize the thickness of the instrument to reduce the size of the incision required to place the instrument on the patient's bone. In process sub-step 232, the user can define cavities 70 over each of the problem areas 174 identified in process step 222. As part of defining the cavities, the user can adjust the shape and size of the planned base plate to adjust the size and / or weight of the planned instrument. Each cavity can have an outer edge that is aligned with the edge 172 of the area 174.

[0061] In process sub-step 234, the user may place surgical instrument guides at locations on the femur model 170 to create a patient-specific orthopaedic instrument model 182, shown in FIG. 15. To do this, a desired cut plane for implantation of an orthopaedic prosthesis may be determined. The planned cut plane may be determined based on the process images, such as the type, size, and location of the orthopaedic prosthesis to be used during the orthopaedic surgical procedure, specific landmarks identified within the images, and constraint data provided by the orthopaedic surgeon in process steps 212 and 214. The type and / or size of the orthopaedic prosthesis may be determined based on the patient's anatomy and the constraint data. For example, the constraint data may determine the type, make, model, size, or other characteristics of the orthopaedic prosthesis. The selection of the orthopaedic prosthesis may also be used for the patient's bones and may be modified based on the medical images such that an orthopaedic prosthesis is selected that matches the constraint data or the orthopaedic surgeon's preferences.

[0062] When placing the guide bodies on the femoral model 170, the user can adjust the size, shape, and position of each guide body as needed. As shown in FIGS. 14 and 15, the user may include one or more drill guide slots to prepare the patient's bone to receive the cutting guide slots and fixation pins. The orientation of the drill guide slots may be based on the planned resection plane and may be adjusted to facilitate resection of the patient's bone. As shown in FIGS. 14 and 15, the guide bodies for the guide slots may be formed by extending outward from the outer surface of the model 182 to the free end.

[0063] It should be understood that sub-steps 228, 230, 232, 234 may be performed in a different order than that described above. For example, a user may choose to first identify a planned resection plane and insert a cutting guide into the femoral model before generating the customized patient-specific negative contour. Additionally, in some embodiments, one or more sub-steps may be omitted.

[0064] After a model of the customized patient-specific orthopaedic surgical instrument is generated in process step 226, the model is validated in process step 236. The model may be validated, for example, by analyzing the rendered model while coupled to a three-dimensional model of the patient's anatomy to verify correlations of cutting guides, reaming guides, bevel and version planes, etc. Additionally, the model may be validated by sending or otherwise providing the model generated in step 226 to an orthopaedic surgeon for review.

[0065] After the model is verified in process step 236, the customized patient-specific orthopedic instrument is fabricated in process step 238. As described above, the customized patient-specific orthopedic instrument may be formed by DMLS, which is a form of 3-D printing technology, as described above. In DMLS, the orthopedic instrument is formed layer by layer using laser sintering, where light melts metal powder and forms the metal structure that defines the orthopedic instrument. As part of the process of fabricating the orthopedic instrument, the metal powder may be melted in layers, resulting in the orthopedic instrument being a single monolithic component that includes multiple fused laminates 184. For example, as shown in FIG. 8, the cutting block 10 includes multiple fused laminates 184 of metal material of uniform thickness. It should be understood that other forms of 3-D printing technology, such as, for example, stereolithography, photosolidification, or resin printing, may be used to fabricate the orthopedic instrument.

[0066] As mentioned above, the cutting block 10 includes a pair of guide bosses 140 having tapered forward surfaces 152. In one exemplary process, the cutting block 10 can be fabricated with the cutting slots 12 having the forward elongated openings 110 facing downward. By tapering the forward surfaces 152, no support structure is required to keep the bosses 140 from collapsing during fabrication. It is understood that other surfaces that face downward during fabrication may be tapered / angled to minimize the amount of support structure required. In an exemplary embodiment, the tapered surfaces 152 have an angle of about 35 degrees. As used herein, it is understood that the term "about" means to allow for normal tolerances caused by manufacturing variations and other design criteria.

[0067] After the customized patient-specific orthopaedic surgical instrument is fabricated, the surgeon may perform the orthopaedic surgical procedure using the customized patient-specific orthopaedic surgical instrument. As described above, the orthopaedic surgeon does not need to determine the appropriate location for the orthopaedic surgical instrument during surgery, which typically requires some degree of estimation on the part of the surgeon, thereby reducing guesswork and / or intraoperative decision-making on the part of the surgeon.

[0068] It should also be appreciated that variations in a patient's bony anatomy may require more than one customized patient-specific orthopaedic instrument to be fabricated in accordance with the methods described herein. For example, a patient may require the implantation of two orthopaedic prostheses. Thus, a surgeon may fabricate a different customized patient-specific orthopaedic instrument for use in replacing each portion of the patient's bony anatomy in accordance with the method 200 of FIG. 11. Each customized patient-specific orthopaedic instrument defines a cutting plane or other relevant parameter for each bone that differs due to variations in the bony anatomy.

[0069] One such instrument, a customized patient-specific tibial cutting block 310, is shown in Figures 16-22. The tibial cutting block 310 includes cutting guide slot 312 locations for guiding a customized patient-specific resection of the proximal end of the patient's tibia along a predetermined resection plane. As described in further detail below, the tibial cutting block 310 is configured to be coupled to the patient's tibia in a unique, predetermined location and orientation. In an exemplary embodiment, the structure of the cutting block 310, similar to that of the femoral cutting block 10 described above, is contoured to reduce size compared to conventional cutting blocks and to avoid contact with undesirable areas of the patient's bone.

[0070] As shown in FIG. 16 , the tibial cutting block 310 includes a base plate 320 and a number of surgical tool guide bodies 322 attached to and extending outwardly from the base plate 320. Like the femoral cutting block 10, the tibial cutting block 310 is a single monolithic component formed via a 3-D printing process from a metallic material, such as stainless steel. In an exemplary embodiment, the base plate 320 includes a pair of arms 324, 326 configured to engage the proximal end of the patient's tibia. The arms 324, 326 are spaced apart from one another such that a notch 328 is defined between their respective inner edges. The notch 328 is sized and shaped to receive the natural spine of the patient's tibia. As such, the base plate 320 is shaped to engage the medial and lateral tibial compartments of the patient's natural tibia to avoid contact with the spine.

[0071] Each of the arms 324, 326 includes a bone-facing surface 336 that engages with either the medial or lateral tibial compartment. As shown in FIG. 19 , each bone-facing surface 336 includes a negative contour 338 configured to receive a portion of the patient's tibia. Each contour 338 includes a unique set of ridges 340 and depressions 342 shaped to engage a corresponding set of depressions and ridges on the patient's tibia. Each of the arms 324, 326 also includes an outer surface 344 disposed opposite the corresponding bone-facing surface 336. In the illustrative embodiment, a plurality of apertures 346 extend through the surfaces 336, 344. Each aperture 346 is illustratively diamond shaped and includes an edge configured to grip bone.

[0072] The base plate 320 also includes an anterior flange 350 configured to engage the proximal end of the patient's tibia. As shown in FIG. 17 , the anterior flange 350 includes a bone-facing surface 352 with a negative contour 354 defined therein. The negative contour 354 is configured to receive a portion of the patient's tibia and includes a unique set of ridges 356 and depressions 358 shaped to engage a corresponding set of depressions and ridges on the patient's tibia. The anterior flange 350 also includes an outer surface 364 disposed opposite the bone-facing surface 352. In the illustrative embodiment, a plurality of apertures 346 also extend through the surfaces 352, 364. Each aperture 346 is illustratively diamond shaped and includes an edge configured to grip bone. It should be understood that in other embodiments, the apertures may have different geometric shapes or may be omitted. Similarly, it should be understood that in other embodiments, the femoral cutting block 10 described above may include such apertures.

[0073] In the exemplary embodiment, the notch 328 defined between the arms 324 and 326 is a customized cavity similar to the customized cavity 70 described above with respect to the femoral cutting block 10. It should also be appreciated that in other embodiments, the base plate 320 may include additional customized cavities similar to the customized cavity 70. Such cavities may be sized and shaped to be placed over problem areas of the patient's tibia at predetermined locations in the bone such that those areas are avoided and do not interfere with placement of the cutting block 310.

[0074] In the illustrative embodiment, the base plate 320 of the cutting block 310 is also low profile to reduce the size of the incision and the amount of bone displacement required to place the cutting block 310. The low profile is customized for the block 310 by minimizing the thickness of the arms 324, 326 and the anterior flange 350. As shown in FIG. 17, a thickness 382 is defined between the outer surface 348 of each arm and the bone surface 336. The outer surface 348 is shaped to follow the geometry of the bone-facing surface 336 of the arms 324, 326. Similarly, as shown in FIG. 19, a thickness 384 is defined between the outer surface 364 of the anterior flange 350 and the bone-facing surface 352, where the outer surface 364 of the flange 350 is shaped to follow the geometry of the bone-facing surface 352 to minimize the thickness 384.

[0075] As shown in FIGS. 16-22, each of the surgical tool guide bodies 322 of the cutting block 310 is attached to the outer surfaces 348, 364 of the arms 324, 326 and extends outwardly therefrom and from the anterior flange 350 to a free end 390 spaced from the base plate 320. In an exemplary embodiment, the guide body 322 includes an elongated body 400 and a pair of bosses 402, 404 extending outwardly from the anterior flange 350. The elongated body 400 includes an elongated opening 410 defined in its free end 390 with a number of interior walls 412 extending inwardly from the opening 410. As shown in FIG. 17, the interior walls 412 extend to another opening 414 defined by an edge 416 of the bone-facing surface 352. The edge 416 illustratively follows a curved path to match the shape of the patient's tibia in that region. The opening 414 cooperates with the inner wall 412 and the elongated opening 410 to define a guide slot 312 that is sized and shaped to guide a surgical tool, such as a cutting blade, into engagement with a patient's bone. As described above, the cutting guide slot 312 is positioned to guide a customized, patient-specific resection of the proximal end of the patient's tibia. Because the edge 416 follows the shape of the patient's tibia, the cutting guide slot 312 provides support for the cutting blade proximate the area under resection.

[0076] As shown in FIGURE 16, each of the bosses 402, 404 is disposed distally of the elongate body 400. An opening 420 is defined in the free end 390 of each of the bosses 402, 404 with an inner wall 422 extending inwardly from the opening 420. As shown in FIGURE 17, each inner wall 422 extends to another opening 424 in the bone-facing surface 352 to define a guide slot 426 that extends through the cutting block 310. In the illustrative embodiment, each guide slot 426 is a drill guide and fixation pin guide hole, sized and shaped to guide a surgical drill and prepare the patient's bone to receive a fixation pin to couple the cutting block 310 to the bone.

[0077] Another customized patient-specific orthopaedic surgical instrument that can be modeled and fabricated using the routine 200 is a customized patient-specific anterior-posterior chamfer cutting block 510 shown in FIGS. 23-30. The cutting block 510 includes a base plate 512 that is customized to fit a distal end 514 of a patient's femur 16 that has been resected, for example, using the femoral cutting block 10 described above. The cutting block 510 also includes a plurality of surgical tool guide bodies 516 that are attached to and extend outwardly from the base plate 512 and are configured to guide surgical tools into contact with the patient's femur, as described in more detail below. In an exemplary embodiment, the cutting block 510 is in the form of a single monolithic component made of a metallic material, such as, for example, stainless steel. As such, the base plate 512 and the guide bodies 516 form a single monolithic metallic block. Similar to the cutting blocks 10, 310, the cutting block 510 is formed by DMLS. As shown in FIG. 27, the cutting block 510 includes multiple fused stacks 184 of metal material of uniform thickness.

[0078] The base plate 512 includes a bone-facing surface 520 and an outer surface 522 disposed opposite the bone-facing surface 520. An outer wall 524 extends between the surface 520 and the surface 522 to define an outer periphery of the base plate 512. As shown in FIG. 25 , the bone-facing surface 520 includes an outer edge 526 connected to the outer wall 524 and customized to match an outer edge 528 (see FIG. 28 ) of the resected distal end 514 of the patient's femur 16. As such, the cutting block 510 is configured to be coupled to the patient's femur 16 in a predetermined unique location and orientation.

[0079] The outer edge 526 includes an upper section 530 that defines a notch 532 in the base plate 512. In an exemplary embodiment, the upper section 530 is curved to match the curvature of an anterior edge section 534 of the resected distal end 514 of the patient's femur 16 (see FIG. 28 ). The outer edge 526 of the bone-facing surface 520 also includes a lower section 540 that defines a notch 542 in the base plate 512. In an exemplary embodiment, the lower section 540 is curved to match the curvature of a posterior edge section 544 of the resected distal end 514 of the patient's femur 16 (see FIG. 28 ), with the shape of the notch 532 substantially matching the shape of the edge of the intercondylar notch 30.

[0080] In the illustrative embodiment, the base plate 512 of the cutting block 510 is low profile to reduce the size of the incision and the amount of bone displacement required to place the cutting block 510. Similar to blocks 10, 310, the low profile is customized for block 510 by minimizing the thickness of the base plate 512 defined between the outer surface 522 and the bone-facing surface 520.

[0081] As shown in FIGS. 22-27, each of the surgical tool guide bodies 516 of the cutting block 510 is attached to an outer surface 522 and extends outwardly from the outer surface 522 to an outer end 550 spaced from the base plate 512. In an exemplary embodiment, the guide bodies 516 include an anterior resection guide body 560 that is disposed over the notch 532 of the base plate 512. The resection guide body 560 includes an elongated opening 562 defined in the outer end 550, which is a free end spaced from the outer ends of the other guide bodies 516. The resection guide body 560 also includes a number of inner walls 564 that extend inwardly from the openings 562. As shown in FIG. 25, the inner walls 564 extend to an opening 566 that opens into the upper notch 532 of the base plate 512. The opening 566 cooperates with the inner wall 564 and the elongated opening 562 to define a guide slot 568 that is sized and shaped to guide a surgical tool, such as a cutting blade, into engagement with the patient's femur and guide the anterior resection of the femur along a predetermined resection plane. The cutting guide slot 568 is positioned in a unique, predetermined location and orientation customized for the patient.

[0082] The guide body 516 includes a posterior resection guide body 570 disposed over the lower notch 542 of the base plate 512. The resection guide body 570 includes an elongated opening 572 defined in an outer end 550, which is a free end spaced from the outer end of the other guide body 516. The resection guide body 570 also includes a number of inner walls 574 extending inwardly from the opening 572. As shown in FIG. 25, the inner walls 574 extend to an opening 576 that opens into the lower notch 542 of the base plate 512. The opening 576 cooperates with the inner walls 574 and the elongated opening 572 to define a guide slot 578 that is sized and shaped to guide a surgical tool, such as a cutting blade, into engagement with the patient's femur and guide a posterior resection of the femur along a predetermined resection plane. The cutting guide slot 568 is positioned in a unique, predetermined location and orientation customized for the patient.

[0083] The guide body 516 also includes a pair of chamfer resection guide bodies 580, 590 disposed between the anterior resection guide body 560 and the posterior resection guide body 570. The resection guide body 580 includes an elongated opening 582 defined in its outer end 550 and a number of inner walls 584 extending inwardly from the opening 582. As shown in FIG. 25 , the inner walls 584 extend to an opening 586 defined in the bone-facing surface 520 of the base plate 512. The opening 586 cooperates with the inner walls 584 and the elongated opening 582 to define a chamfer resection guide slot 588 that is sized and shaped to guide a surgical tool, such as a cutting blade, into engagement with the patient's femur and to guide a chamfer resection of the femur along a predetermined resection plane that extends at an angle relative to the resection plane defined by the other cutting guide slots. The cutting guide slot 588 is positioned in a unique, predetermined location and orientation customized for that patient.

[0084] The resection guide body 590 includes an elongated opening 592 defined in its outer end 550 and a number of interior walls 594 extending inwardly from the opening 592. As shown in FIG. 25 , the interior walls 594 extend to an opening 596 defined in the bone-facing surface 520 of the base plate 512. The opening 596 cooperates with the interior walls 594 and the elongated opening 592 to define another chamfer guide slot 598 that is sized and shaped to guide a surgical tool, such as a cutting blade, into engagement with the patient's femur and to guide another chamfer resection of the femur along a predetermined resection plane that also extends at an angle relative to the resection plane defined by the other cutting guide slots. The cutting guide slot 598 is positioned in a unique, predetermined location and orientation customized for the patient.

[0085] As shown in Figures 22-27, the outer ends 550 of the chamfer resection guide bodies 580, 590 are joined to define a passageway 600 between the surfaces of the guide bodies 580, 590 and the base plate 512. In an exemplary embodiment, the passageway 600 has a triangular cross-section. As shown in Figure 27, the guide slots 588, 598 of the guide bodies 580, 590 intersect and the inner walls 584, 594 of the guide bodies 580, 590 include multiple openings 602 at the intersections such that the guide slots 588, 598 are in communication with one another.

[0086] The guide body 516 also includes a pair of bosses 604, 606 extending outwardly from the base plate 512 between the chamfer resection guides 580, 590 and the posterior resection guide 570. The outer end 550 of each of the bosses 604, 606 defines an opening 610 with an inner wall 612 extending inwardly from the opening 610. As shown in FIG. 17 , each inner wall 612 extends to another opening 614 in the bone-facing surface 520 to define a guide slot 616 that extends through the cutting block 510. In the illustrative embodiment, each guide slot 616 is a drill guide and fixation pin guide hole sized and shaped to guide a surgical drill and prepare the patient's bone to receive a fixation pin for coupling the block 510 to the patient's femur.

[0087] As described above, the cutting block AP chamfer cutting block 510 is customized to fit the resected distal end 514 of the patient's femur 16, as shown in FIG. 28. The resected distal end 514 includes a resected distal surface 620 bounded by an outer edge 528. As shown in FIG. 28, the outer edge 528 includes an anterior edge section 534 that defines the distal opening of the patient's trochlear groove 166, and a posterior edge section 544 that defines the distal opening of the patient's intercondylar notch 30. In an exemplary embodiment, the size and shape of the resected distal surface 620 is planned pre-operatively, for example, during execution of the routine 200. In other words, when the surgeon or other user defines the distal resection plane to be created using the cutting block 10, the size and shape of the resected distal surface 620 is also modeled. Using the model of the resected distal surface 620 , a user can generate a 3-D computer model of the AP chamfer cutting guide block 510 during process step 226 of the routine 200 .

[0088] 29 and described above, the outer edge 526 of the base plate 512 of the cutting block 510 is shaped to match the outer edge 528 of the resected distal surface 620. Specifically, the upper section 530 of the plate outer edge 526 is curved to match the curvature of the anterior edge section 534 of the outer edge 528 of the resected distal surface 620, and the lower section 540 of the plate outer edge 526 is curved to match the curvature of the posterior edge section 544 of the outer edge 528 of the resected distal surface 620. The upper notch 532 of the base plate 512 is shaped to match the distal opening of the patient's trochlear groove 166. The base plate 512 also includes a lower notch 542 that is shaped to fit the distal opening of the patient's intercondylar notch 30. 30, when the cutting block 510 is properly positioned on the patient's bone, the outer edge 526 of the block and the outer edge 528 of the bone coincide and the notches 532, 542 are aligned with the distal opening of the groove 166 and notch 30. In that way, the surgeon or other user is notified when the block is properly positioned and can correct any misalignment with the patient's bone before commencing any resection with the block 510.

[0089] 31-37, another embodiment of a customized patient-specific femoral cutting block (hereinafter, cutting block 710) is shown. The embodiment of FIGS. 31-37 includes many features that are the same as or similar to those shown in the embodiment of FIGS. 1-10. Similar features are identified in FIGS. 31-37 with the same reference numbers used in FIGS. 1-10. The cutting block 710 includes cutting guide slots 712 positioned to guide a customized patient-specific resection of the distal end of the patient's femur. As described in more detail below, the femoral cutting block 710 is configured to be coupled to the patient's femur in a unique, predetermined position and orientation. In the illustrative embodiment, the structure of the cutting block 710 is contoured to reduce size as compared to conventional cutting blocks and to avoid contact with undesired areas of the patient's bone.

[0090] 31 , the femoral cutting block 710 includes a base plate 720 and a number of surgical tool guide bodies 722 attached to and extending outwardly from the base plate 720. In an exemplary embodiment, the femoral cutting block 710 is a single monolithic component formed from a metallic material, such as, for example, stainless steel, via DMLS techniques. As such, the base plate 720 and the guide bodies 722 form a single monolithic metallic block.

[0091] The base plate 720 includes a posterior section including a pair of arms 24, 26 configured to engage the distal end of a patient's femur. The arms 24, 26 are spaced apart from one another such that a notch 28 is defined between inner edges of the arms 24, 26. The notch 28 is sized and shaped to correspond to the natural intercondylar notch of the patient's femur. In this manner, contact within the bone surface with the natural intercondylar notch 30, which can be difficult to model, is avoided.

[0092] Each of the arms 24, 26 has a bone-contacting or bone-facing surface 36 that engages one of the natural condyles 32, 34. In the exemplary embodiment, each bone-facing surface 36 includes a number of negative contours 38 configured to receive a portion of the natural condyle 32, 34. Each of the arms 24, 26 also includes an outer surface 48 disposed opposite the corresponding bone-facing surface 36. In the exemplary embodiment, each outer surface 48 is substantially smooth.

[0093] As shown in FIG. 31 , the base plate 720 also includes an anterior section including an anterior flange 750 configured to engage a distal end of the patient's femur. In the exemplary embodiment, the flange 750 is spaced from the arms 24, 26. The anterior flange 750 includes a bone-facing surface 752 including a number of negative contours 754 configured to receive a portion of the patient's femur. For example, as shown in FIGS. 32 and 34 , the contour 754 of the anterior flange 750 has a unique set of ridges 756 and depressions 758 shaped to engage a corresponding unique set of depressions and ridges on the patient's femur. The anterior flange 750 also includes an outer surface 764 disposed opposite the bone-facing surface 752. In the exemplary embodiment, the outer surface 764 is substantially smooth.

[0094] The base plate 720 also includes a number of customized cavities 70 that are sized to be placed over areas of the bone at a predetermined location that may contain defects or be damaged or difficult to model. In that way, the cavities 70 can be sized to avoid contact with those areas and not impede placement of the cutting block 10 at a predetermined location and orientation. In an exemplary embodiment, the notch 28 defined between the arms 24 and 26 is one of the customized cavities. As shown in FIGS. 31-33, the customized cavity 70 also includes an opening 772 that extends through the bone-facing surface 752 of the anterior flange 750. As shown in FIGS. 31-32, the customized cavity 70 also includes a pair of channels 74, 76 defined in the bone-facing surface 752 of the anterior flange 750.

[0095] As discussed above, the cutting block 710 includes a number of surgical tool guide bodies 722 configured to guide a surgical tool into contact with a patient's bone. In an exemplary embodiment, the guide body 722 includes a distal resection guide body 780 extending forwardly from the forward ends of the arms 24, 26. The distal resection guide body 780 includes an elongated opening 782 defined at an outer end 784 thereof and a number of inner walls 786 extending inwardly from the opening 782. As shown in FIG. 32 , the inner wall 786 extends to another opening 788 defined in the bone-facing surface 762. The opening 788 cooperates with the inner wall 786 and the elongated opening 782 to define a cutting guide slot 712 that is sized and shaped to guide a surgical tool, such as, for example, a cutting blade, into engagement with a patient's bone. As described above, the cutting guide slot 712 is positioned to guide a customized, patient-specific resection of the distal end of the patient's femur.

[0096] 35 , the inner wall 786 includes an inner inner wall 790 that defines an inside of the guide slot 712 and an outer inner wall 792 that defines an outside of the guide slot 712. In the exemplary embodiment, the outer inner wall 792 extends at an oblique angle relative to the inner inner wall 790 to guide the resection of the patient's bone. The oblique angle, as well as the remainder of the cutting guide block 710, is customized to the patient's bone anatomy. It is understood that the inner inner wall may be angled in other embodiments.

[0097] The tool guide body 722 of the block 710 also includes a pair of guide bosses 796, 798 integral with a forward flange 750 extending proximally from the guide body 780. An opening 800 is defined in an outer surface 802 of each of the bosses 796, 798 with an inner wall 804 extending inwardly from the opening 800. As shown in FIG. 32 , each inner wall 804 extends to another opening 806 that opens into one of the channels 74, 76 to define a guide slot 808 that extends through the cutting block 710. In the illustrative embodiment, each guide slot 808 is a drill guide and fixation pin guide hole sized and shaped to guide a surgical drill and prepare the patient's bone to receive a fixation pin for coupling the bone to the block 710.

[0098] The cutting block 710 has a low profile to reduce the size of the incision and the amount of bone displacement required to place the cutting block 710. The low profile is customized for the block 710 by adjusting the shape and size of the base plate and guide body. For example, as shown in FIG. 36, the guide boss 796 has a length 810 that is shorter than the length 812 of the guide boss 798 shown in FIG. 36. Similarly, the outer surface 48 of each arm is convexly curved to follow the concave curvature of the bone-facing surface 36 of the arm.

[0099] The guide body 722 of the cutting block 710 also includes a pair of rearward guide bosses 140 attached to and extending distally from the outer surfaces 48 of the arms 24, 26, respectively. Each rearward guide boss 140 includes a guide slot 142 that is sized and shaped to guide surgical drills and fixation pins into engagement with the patient's bone for coupling the block 710 to the bone.

[0100] 38-41, another embodiment of a customized patient-specific cutting block (hereinafter cutting block 910, 1010, 1110) is shown. The embodiment of FIGS. 38-41 includes many features that are the same as or similar to those shown in the above-described embodiments. Similar features are identified in FIGS. 38-41 with the same reference numbers used with reference to the above-described embodiments. Referring now to FIG. 38, the cutting block 910 includes cutting guide slots 912 positioned to guide a customized patient-specific resection of the distal end of the patient's femur. In the exemplary embodiment, the cutting block 910 includes a number of bone-facing surfaces 916 having a negative contour 38 configured to receive portions of the patient's bone.

[0101] Similar to the tibial cutting block 310, the cutting block 910 includes a number of apertures 914 extending through the bone-facing surface 916 and the outer surface 918 of the cutting block 910. Each aperture 914 is illustratively cylindrical and includes a circular edge configured to grip the bone. The apertures 914 also extend through the surface of the anterior resection guide body 920 and open into the guide slot 912. As such, the apertures 914 provide a viewing window for a surgeon or other user to monitor the movement of the cutting saw blade and review the fit of the block 910 to the bone. It should be understood that similar apertures may be incorporated into any of the embodiments described herein. Additionally, it should be understood that the apertures may take on other sizes and shapes depending on the nature of the patient's bone anatomy.

[0102] The cutting block 910 includes a number of other surgical tool guide bodies 920. In the exemplary embodiment, each of the tool guide bodies 920 is a drill guide and a fixation guide configured to guide a fixation pin into engagement with a patient's bone to couple the cutting block 910 to the bone.

[0103] 39 , a cutting block 1010 includes cutting guide slots 1012 positioned to guide a customized, patient-specific resection of the distal end of a patient's femur. In an exemplary embodiment, the cutting block 1010 includes a number of bone-facing surfaces 1016 having negative contours 38 configured to receive portions of the patient's bone.

[0104] Similar to cutting block 710, cutting block 1010 includes a distal resection guide body 1020 having an elongated opening 1022 defined in a free end 1024 thereof, and a number of interior walls 1026 extending inwardly from the opening 1022 to define a cutting guide slot 1012 sized and shaped to guide a surgical tool, such as a cutting blade, into engagement with a patient's bone.

[0105] 39 , the inner wall 1026 includes an inner inner wall 1030 that defines an inner side of the guide slot 1012 and a lateral inner wall 1032 that defines an outer side of the guide slot 1012. In an exemplary embodiment, the lateral inner wall 1032 extends at an oblique angle relative to the inner inner wall 1030 to guide the resection of the patient's bone. The oblique angle, as well as the remainder of the cutting guide block 1010, is customized to the patient's bony anatomy.

[0106] The cutting block 1010 includes a number of other surgical tool guide bodies 1028. In the exemplary embodiment, each of the tool guide bodies 1028 is a drill guide and a fixation guide configured to guide a fixation pin to engage a patient's bone and couple the cutting block 1010 to the bone.

[0107] 40-41 , a cutting block 1110 includes a pair of cutting guide slots 1112, 1114 positioned to guide a customized, patient-specific resection of the distal end of a patient's femur. In an exemplary embodiment, the cutting block 1110 includes a number of bone-facing surfaces 1116 having a negative contour 38 configured to receive portions of the patient's bone.

[0108] The cutting block 1110 includes a distal resection guide body 1120 including a pair of elongated openings 1122 defined in a free end 1124 thereof and a number of interior walls 1126 extending inwardly from the openings 1122. Each opening 1122 and interior wall 1126 cooperates to define a cutting guide slot 1112, 1114 sized and shaped to guide a surgical tool, such as a cutting blade, into engagement with a patient's bone. The cutting guide slot 1114 is located distal to the cutting guide slot 1112 and provides the surgeon with the option of making a second pre-planned resection during surgery, thereby providing the surgeon with additional flexibility during surgery while still maintaining the benefits of pre-operative planning.

[0109] 40-41 , the cutting block 1110 includes a number of other surgical tool guide bodies 1130. In an exemplary embodiment, each of the tool guide bodies 1130 is a drill guide and a fixation guide configured to guide fixation pins into engagement with a patient's bone to couple the cutting block 1110 to the bone.

[0110] It should be appreciated that in some embodiments, an orthopaedic surgical instrument is disclosed that includes a customized patient-specific surgical instrument. The customized patient-specific surgical instrument includes a metallic base plate sized to be placed on a patient's bone. The base plate has a bone-facing surface including a customized patient-specific concave contour configured to receive a corresponding convex contour of the patient's bone, and an outer surface disposed opposite the bone-facing surface. The customized patient-specific surgical instrument also includes a metallic guide body attached to the outer surface and extending from the outer surface to a free end. The guide body includes an elongated opening defined in the free end. A guide slot extends from the opening in the guide body through a first opening defined in the bone-facing surface. The guide slot is sized and shaped to guide a surgical tool into engagement with the patient's bone.

[0111] In some embodiments, the guide slot may be sized and shaped to guide a fixation pin into engagement with the patient's bone. In some embodiments, the guide slot may be sized and shaped to guide a cutting saw blade into engagement with the patient's bone.

[0112] In some embodiments, the customized patient-specific surgical instrument can also include a boss attached to the outer surface and extending from the outer surface to a free end spaced from the free end of the guide body. The boss can include an opening defined in its free end, and the drill guide slot can extend from the opening in the boss through a second opening defined in the bone-facing surface. The drill guide slot can be sized and shaped to guide a surgical drill or fixation pin into engagement with the patient's bone.

[0113] In some embodiments, the boss may extend from a base attached to the outer surface of the base plate to a free end, the base may be wider than the free end, and the boss may include a tapered surface extending from the base to the free end.

[0114] In some embodiments, the cutting guide slot may extend in an anterior-posterior direction, the drill guide slot may be a first drill guide slot extending in an inferior-superior direction, and the customized patient-specific surgical instrument may further comprise a second drill guide slot extending in an anterior-posterior direction from the second opening in the guide body through a third opening defined in the bone-facing surface. The second drill guide slot may be sized and shaped to guide a surgical drill into engagement with the patient's bone.

[0115] In some embodiments, the base plate may include a pair of rearwardly extending arms, each of which may include a portion of a customized patient-specific negative contour configured to receive a portion of a corresponding convex contour of a patient's bone.

[0116] In some embodiments, the customized patient-specific surgical instrument may include a customized patient-specific cavity defined in the base plate. The cavity may be sized and shaped to be positioned over a portion of the patient's bone to prevent contact between the portion of the patient's bone and the customized patient-specific surgical instrument. Further, in some embodiments, the cavity is positioned proximal to the guide body.

[0117] In some embodiments, the base plate may include a first section attached to one of the distal and proximal ends of the guide body and a second section spaced apart from the first section of the base plate and attached to the other of the distal and proximal ends of the guide body.

[0118] In some embodiments, the first section may include a pair of rearwardly extending arms. Each arm may include a portion of a customized patient-specific negative contour configured to receive a portion of a corresponding convex contour of a patient's bone. Additionally, in some embodiments, the customized patient-specific surgical instrument may include a plurality of openings extending through the bone-facing and outer surfaces of the rearwardly extending arms of the first section of the base plate and the bone-facing and outer surfaces of the second section.

[0119] In some embodiments, the customized patient-specific surgical instrument may be a single monolithic metallic component that includes multiple laminates.

[0120] It should be appreciated that in some embodiments, the customized patient-specific surgical instrument comprises a metallic guide body extending from a rear end to a free leading end. The guide body includes an elongated opening defined in its free leading end. A cutting guide slot extends from the opening in the guide body. The guide slot is sized and shaped to guide a cutting saw blade into engagement with a patient's bone. The customized patient-specific surgical instrument includes a first plate section extending from the rear end of the metallic guide body, the first plate section including a pair of rearwardly extending arms. Each arm includes a first portion of a customized patient-specific concave contour configured to receive a first portion of a corresponding convex contour of a patient's bone. The customized patient-specific surgical instrument also includes a second plate section spaced apart from the first plate section and extending from the rear end of the metallic guide body. The second plate section includes a bone-facing surface including a second portion of a customized patient-specific concave contour configured to receive a second portion of a corresponding convex contour of a patient's bone.

[0121] In some embodiments, the customized patient-specific surgical instrument can also include a first boss attached to the second plate section and extending from the second plate section to an end spaced from the free leading end of the guide body. The first boss can include an opening defined in an end thereof, and the first drill guide slot can extend from the opening in the first boss. The first drill guide slot can be sized and shaped to guide a surgical drill into engagement with the patient's bone.

[0122] In some embodiments, the customized patient-specific surgical instrument may further include a second boss attached to a first of the pair of rearwardly extending arms and extending therefrom to a free end. The second boss may include an opening defined in its free end and a second drill guide slot extending from the opening in the second boss. The second drill guide slot may be sized and shaped to guide a surgical drill into engagement with a patient's bone.

[0123] In some embodiments, the customized patient-specific surgical instrument may further include a third boss attached to a second of the pair of rearwardly extending arms and extending therefrom to a free end. The third boss may include an opening defined in its free end and a third drill guide slot extending from the opening in the third boss. The third drill guide slot may be sized and shaped to guide a surgical drill into engagement with a patient's bone.

[0124] Additionally, in some embodiments, the customized patient-specific surgical instrument may be a single monolithic metallic component that includes multiple laminates.

[0125] According to another aspect, it should be appreciated that in some embodiments, a single monolithic metallic customized patient-specific surgical instrument includes multiple laminations of metallic material. The single monolithic metallic customized patient-specific surgical instrument includes a bone-facing surface configured to engage a patient's bone. The bone-facing surface includes a customized patient-specific concave contour configured to receive a corresponding convex contour of the patient's bone. The single monolithic metallic customized patient-specific surgical instrument includes an exterior surface disposed opposite the bone-facing surface and a guide slot defined in the bone-facing surface. The guide slot is sized and shaped to guide a surgical tool into engagement with the patient's bone.

[0126] It will be appreciated that in some embodiments, a method of manufacturing a customized patient-specific orthopaedic surgical instrument includes generating a three-dimensional model of a patient's bone based on patient-specific data, identifying a first region of the three-dimensional model of the patient's bone, defining an outer boundary of the customized patient-specific surgical instrument on the three-dimensional model of the patient's bone, generating a customized patient-specific surgical instrument model within the outer boundary, the customized patient-specific surgical instrument model comprising a bone-facing surface including a customized patient-specific concave contour that receives a corresponding convex contour of the patient's bone, and fabricating the customized patient-specific orthopaedic surgical instrument from a metallic material based on the customized patient-specific orthopaedic surgical instrument model. The step of generating the customized patient-specific surgical instrument model includes defining a cavity in the bone-facing surface over the first region of the three-dimensional model of the patient's bone. The cavity has an outer edge aligned with or larger than an outer edge of the first region. The step of generating the customized patient-specific surgical instrument model also includes generating an outer surface of the customized patient-specific surgical instrument opposite the bone-facing surface, extending a guide body outwardly from the outer surface of the customized patient-specific surgical instrument model to a free end, and defining a guide slot within the guide body, the guide slot being sized and shaped to guide a surgical tool into engagement with the patient's bone.

[0127] In some embodiments, the method can also include identifying a planned resection plane on the three-dimensional model of the patient's bone based on the patient-specific data. Defining a guide slot through the guide body can include aligning the guide slot with the planned resection plane and sizing and shaping the guide slot to guide a cutting saw blade along the planned resection plane to engage the patient's bone.

[0128] Further, in some embodiments, the step of sizing and shaping the guide slot includes defining the guide slot between an inner sidewall and an outer sidewall of the guide body, at least one of the inner sidewall and the outer sidewall being angled relative to the other of the inner sidewall and the outer sidewall.

[0129] In some embodiments, the guide slot may be a first guide slot, and generating the customized patient-specific surgical instrument model may further include extending a boss outwardly from an outer surface of the customized patient-specific surgical instrument model to a free end spaced from the free end of the guide body, and defining a drill guide slot in the boss. In some embodiments, extending the boss outwardly from the outer surface can include defining a tapered surface on a first side of the boss, and fabricating the customized patient-specific orthopaedic surgical instrument from the metallic material includes stacking the metallic material in a fabrication machine such that the tapered surface faces downward in the fabrication machine.

[0130] In some embodiments, generating the customized patient-specific surgical instrument model may further include defining a plurality of apertures extending through the exterior surface and the bone-facing surface.

[0131] In some embodiments, generating the customized patient-specific surgical instrument model can further include defining a second plurality of apertures through the guide body of the customized patient-specific surgical instrument model. Further, in some embodiments, each of the apertures may include a diamond shaped opening.

[0132] In some embodiments, the step of extending the guide body outwardly from an outer surface of the customized patient-specific surgical instrument model to a free end can include defining a tapered surface on a first side of the guide body, and fabricating the customized patient-specific orthopaedic surgical instrument from the metal material can include stacking the metal material in a fabrication machine such that the tapered surface faces downward in the fabrication machine.

[0133] In some embodiments, fabricating the customized patient-specific orthopaedic surgical instrument from a metallic material based on the customized patient-specific surgical instrument model may include forming the customized patient-specific orthopaedic surgical instrument as a single monolithic component.

[0134] In some embodiments, a single monolithic component may include multiple laminations of metallic materials.

[0135] It should be appreciated that in some embodiments, a method of manufacturing a customized patient-specific orthopaedic surgical instrument includes generating a three-dimensional model of a patient's bone based on the patient-specific data, defining an outer boundary of the customized patient-specific surgical instrument on the three-dimensional model of the patient's bone, generating a customized patient-specific surgical instrument model within the outer boundary, the customized patient-specific surgical instrument model including a customized patient-specific bone-facing surface, and fabricating the customized patient-specific orthopaedic surgical instrument from a metallic material based on the customized patient-specific orthopaedic surgical instrument model. The step of generating the customized patient-specific surgical instrument model includes generating an outer surface of the customized patient-specific surgical instrument opposite the bone-facing surface, extending a guide body outwardly from the outer surface of the customized patient-specific surgical instrument model to a free end, and defining a guide slot within the guide body. The guide slot may be sized and shaped to guide a surgical tool into engagement with the patient's bone.

[0136] In some embodiments, the method includes planning a resection surface of a patient's bone, and generating the customized patient-specific surgical instrument model may include shaping an outer edge of the bone-facing surface to match an outer edge of the planned resection surface of the patient's bone.

[0137] In some embodiments, the guide body may be a first guide body, and generating the customized patient-specific surgical instrument model may further include extending a second guide body outwardly from an outer surface of the customized patient-specific surgical instrument model to an end spaced from the free end of the first guide body, and defining a second guide slot in the second guide body, the second guide slot being sized and shaped to guide a surgical tool into engagement with a patient's bone and extending transversely to the first guide slot.

[0138] In some embodiments, generating the customized patient-specific surgical instrument model can further include extending a third guide body outwardly from an outer surface of the customized patient-specific surgical instrument model to a free end spaced from the first guide body, and defining a third guide slot, the second guide slot sized and shaped to guide a surgical tool into engagement with a patient's bone and intersecting the second cutting guide slot.

[0139] Additionally, in some embodiments, the second guide body may include a boss having a tapered outer surface, and the second guide slot may be a drill guide slot sized and shaped to guide a surgical drill into engagement with the patient's bone.

[0140] In some embodiments, fabricating the customized patient-specific orthopaedic surgical instrument from a metallic material based on the customized patient-specific surgical instrument model may include forming the customized patient-specific orthopaedic surgical instrument as a single monolithic component.

[0141] In some embodiments, fabricating the customized patient-specific orthopaedic surgical instrument may include fabricating the customized patient-specific surgical instrument by operating a three dimensional metal printer to form a lay-up of metal material.

[0142] It will be appreciated that in some embodiments, a method for designing a customized patient-specific orthopaedic surgical instrument includes generating a three-dimensional model of a patient's bone based on the patient-specific data, defining an outer boundary of the customized patient-specific surgical instrument on the three-dimensional model of the patient's bone, and generating a customized patient-specific surgical instrument model within the outer boundary. The customized patient-specific surgical instrument model includes a customized patient-specific bone-facing surface. In some embodiments, generating the customized patient-specific surgical instrument model includes generating an outer surface of the customized patient-specific surgical instrument opposite the bone-facing surface, extending a guide body outwardly from the outer surface of the customized patient-specific surgical instrument model to a free end, and defining a guide slot in the guide body, the guide slot being sized and shaped to guide a surgical tool into engagement with the patient's bone.

[0143] While the present disclosure has been illustrated and described in detail in the drawings and foregoing description, it is understood that such illustration and description is merely illustrative in nature and should not be regarded as restrictive, and that merely illustrative embodiments have been shown and described, and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.

[0144] There are several advantages of the present disclosure that derive from the various features of the devices, systems, and methods described herein. It should be noted that alternative embodiments of the devices, systems, and methods of the present disclosure may not include all of the features described, but still benefit from at least some of the advantages of such features. Those skilled in the art may readily devise their own implementations of the devices, systems, and methods that incorporate one or more of the features of the present invention and are within the spirit and scope of the present disclosure.

[0145] [Embodiment] (1) An orthopedic surgical instrument, a base plate sized to be placed on the resected surface of the distal end of the patient's femur, the base plate having a bone-facing surface, a distal surface disposed opposite the bone-facing surface, and an outer wall extending between the bone-facing surface and the distal surface; a body attached to the distal surface and extending from the distal surface to a free distal end, the body including an elongated opening defined in the free distal end; a cutting guide slot extending from the opening in the body through a first opening defined in the bone-facing surface, the cutting guide slot being sized to receive a cutting saw blade; a boss attached to the distal surface and extending from the distal surface to a free distal end spaced from the free distal end of the body, the boss including an opening defined in the free distal end; a drill guide slot extending from the opening in the boss through a second opening defined in the bone-facing surface, the drill guide slot being sized to receive a surgical drill; 1. An orthopaedic surgical instrument comprising: a metallic customized patient-specific surgical instrument comprising: (2) The orthopaedic surgical instrument of claim 1, wherein the bone-facing surface includes a customized, patient-specific periphery shaped to match a periphery of the resected surface of the distal end of the patient's femur. (3) the metallic customized patient-specific surgical instrument includes a notch defined by a section of the periphery; the cutting guide slot opens into the notch; An orthopedic surgical instrument as described in embodiment 1. (4) The orthopaedic surgical instrument of claim 3, wherein the section of the outer edge is an upper section, whereby the notch is defined in an upper end of the metallic customized patient-specific surgical instrument. (5) The orthopaedic surgical instrument of claim 3, wherein the section of the outer edge is a lower section, whereby the notch is defined in a lower end of the metallic customized patient-specific surgical instrument.

[0146] (6) The body is a first body, the cutting guide is a first cutting guide, and the metallic customized patient-specific surgical instrument comprises: a second body attached to the distal surface and extending from the distal surface to a distal end spaced from the distal ends of the first body and the boss, the second body including an elongated opening defined in its distal end; a second cutting guide slot extending from the opening in the second body through a third opening defined in the bone-facing surface, the second cutting guide slot being sized to receive a cutting saw blade; 2. The orthopedic surgical instrument of claim 1, further comprising: (7) the first cutting guide defines a first cutting surface; the second cutting guide defines a second cutting plane that is angled relative to the first cutting plane; An orthopedic surgical instrument as described in embodiment 1. (8) The metallic customized patient-specific surgical instrument, a third body attached to the distal surface and extending from the distal surface to a distal end attached to the distal end of the second body, the third body including an elongated opening defined in its distal end; a third cutting guide slot extending from the opening in the third body through a fourth opening defined in the bone-facing surface, the third cutting guide slot sized to receive a cutting saw blade and intersecting the second cutting guide slot; 8. The orthopedic surgical instrument of embodiment 7, further comprising: (9) The orthopedic surgical instrument of claim 8, wherein the third cutting guide defines a third cutting surface that is angled relative to the first cutting surface and the second cutting surface. (10) The orthopedic surgical instrument of embodiment 8, wherein a passage is defined between a surface of the second body, a surface of the third body, and the distal surface of the base plate.

[0147] (11) The metallic customized patient-specific surgical instrument, a fourth body attached to the distal surface and extending from the distal surface to a free distal end spaced from the distal ends of the first body, the second body, and the third body, the fourth body including an elongated opening defined in its distal end; a fourth cutting guide slot extending from the opening in the fourth body through a fifth opening defined in the bone-facing surface, the fourth cutting guide slot sized to receive a cutting saw blade and intersecting the second cutting guide slot. An orthopedic surgical instrument as described in embodiment 8. (12) The orthopaedic surgical instrument of claim 1, wherein the metallic customized patient-specific surgical instrument comprises multiple laminates of metallic material. (13) An orthopedic instrument comprising: a base plate sized to be placed on the resected surface of the distal end of the patient's femur, the base plate having a bone-facing surface, a distal surface disposed opposite the bone-facing surface, and an outer wall extending between the bone-facing surface and the distal surface; an anterior resection guide attached to the distal surface and extending from the distal surface to a free distal end, the anterior resection guide including an anterior cutting guide slot sized to receive a cutting saw blade; a posterior resection guide attached to the distal surface and extending from the distal surface to a free distal end, the posterior resection guide including a posterior cutting guide slot sized to receive a cutting saw blade; a pair of chamfer cutting guides attached to and extending from the distal surface, each chamfer cutting guide including a chamfer cutting guide slot sized to receive a cutting saw blade, each chamfer cutting guide slot extending obliquely relative to the other cutting guide slot; 1. An orthopaedic surgical instrument comprising: a metallic customized patient-specific surgical instrument comprising: (14) The metallic customized patient-specific surgical instrument, a boss attached to the distal surface and extending from the distal surface to a free distal end spaced from the free distal end of the body, the boss including an opening defined in the free end; a drill guide slot extending from the opening in the boss through a second opening defined in the bone-facing surface, the drill guide slot being sized to receive a surgical drill. An orthopedic surgical instrument as described in embodiment 13. 15. The orthopaedic surgical instrument of claim 14, wherein the bone-facing surface comprises a customized, patient-specific periphery shaped to match a periphery of the resected surface of the distal end of the patient's femur.

[0148] (16) the metallic customized patient-specific surgical instrument includes an upper notch defined by a section of the periphery; the anterior cutting guide slot opens into the upper notch; An orthopedic surgical instrument as described in embodiment 15. (17) The metallic customized patient-specific surgical instrument includes a lower notch defined by a section of the periphery; the rear cutting guide slot opens into the lower notch; An orthopedic surgical instrument as described in embodiment 15. (18) The orthopaedic surgical instrument of claim 13, wherein the metallic customized patient-specific surgical instrument comprises multiple laminates of metallic material. (19) A method of performing orthopedic surgery, comprising: Aligning the customized patient-specific surgical instrument with the resected distal surface of the patient's bone; placing the customized patient-specific surgical instrument in contact with the resected distal surface; rotating the customized patient-specific surgical instrument over the resected distal surface to align a perimeter edge of the resected distal surface with a customized patient-specific perimeter of a bone-facing surface of the customized patient-specific surgical instrument; and inserting a cutting saw through a cutting guide slot defined in the customized patient-specific surgical instrument to resect a bone of the patient. (20) The method of claim 19, wherein the customized patient-specific surgical instrument includes an anterior cutting guide slot, a posterior cutting guide slot, and a pair of chamfered cutting guide slots.

Claims

1. 1. An orthopaedic surgical instrument comprising: a base plate sized to be placed on the resected surface of the distal end of the patient's femur, the base plate having a bone-facing surface, a distal surface disposed opposite the bone-facing surface, and an outer wall extending between the bone-facing surface and the distal surface; a body attached to the distal surface and extending from the distal surface to a free distal end, the body including an elongated opening defined in the free distal end; a cutting guide slot extending within the body from the opening in the body to a first opening defined in the bone-facing surface, the cutting guide slot being sized to receive a cutting saw blade; a boss attached to the distal surface and extending from the distal surface to a free distal end spaced from the free distal end of the body, the boss including an opening defined in the free distal end; a drill guide slot extending within the boss from the opening in the boss to a second opening defined in the bone-facing surface, the drill guide slot being sized to receive a surgical drill; a metallic customized patient-specific surgical instrument comprising: the body having a proximal end and a distal end, the proximal end being attached to the distal surface, the body extending from the proximal end to the distal end so as to protrude away from the distal surface, the distal end defining the free distal end of the body; the bone-facing surface includes a customized, patient-specific periphery shaped to match a periphery of the resected surface of the distal end of the patient's femur.

2. the metallic customized patient-specific surgical instrument includes a notch defined by a section of the periphery; the cutting guide slot opens into the notch; 10. The orthopaedic surgical instrument of claim 1.

3. The orthopaedic surgical instrument of claim 2 , wherein said section of the outer edge is an upper section, whereby said notch is defined in an upper end of the metallic customized patient-specific surgical instrument.

4. The orthopaedic surgical instrument of claim 2, wherein said section of the outer edge is a lower section, whereby said notch is defined in a lower end of the metallic customized patient-specific surgical instrument.

5. the body being a first body, the metallic customized patient-specific surgical instrument comprising: a second body attached to the distal surface and extending from the distal surface to a distal end spaced from the distal ends of the first body and the boss, the second body including an elongated opening defined in its distal end; a second cutting guide slot extending within the second body from the opening in the second body to a third opening defined in the bone-facing surface, the second cutting guide slot being sized to receive a cutting saw blade; The orthopaedic surgical instrument of claim 1 further comprising:

6. said metallic customized patient-specific surgical instrument comprising: a third body attached to the distal surface and extending from the distal surface to a distal end attached to the distal end of the second body, the third body including an elongated opening defined in its distal end; a third cutting guide slot extending within the third body from the opening in the third body to a fourth opening defined in the bone-facing surface, the third cutting guide slot sized to receive a cutting saw blade and intersecting the second cutting guide slot; The orthopaedic surgical instrument of claim 5 further comprising:

7. The orthopaedic surgical instrument of claim 6 , wherein a passageway is defined between the second body surface, the third body surface, and the distal surface of the baseplate.

8. said metallic customized patient-specific surgical instrument comprising: a fourth body attached to the distal surface and extending from the distal surface to a free distal end spaced from the distal ends of the first body, the second body, and the third body, the fourth body including an elongated opening defined in its distal end; a fourth cutting guide slot extending within the fourth body from the opening in the fourth body to a fifth opening defined in the bone-facing surface, the fourth cutting guide slot sized to receive a cutting saw blade and intersecting the second cutting guide slot.

7. The orthopaedic surgical instrument of claim 6.

9. The orthopaedic surgical instrument of claim 1 , wherein the metallic customized patient-specific surgical instrument comprises multiple laminations of metallic material.

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