WO2012024317A2

WO2012024317A2 - Orthopedic block inserts

Info

Publication number: WO2012024317A2
Application number: PCT/US2011/047957
Authority: WO
Inventors: Jason S. Jordan; Mark E. Nadzadi; David T. Mehl; Abraham Biglari Salehi
Original assignee: Smith & Nephew, Inc.
Priority date: 2010-08-16
Filing date: 2011-08-16
Publication date: 2012-02-23
Also published as: WO2012024317A3; WO2012024318A3; WO2012024318A2

Abstract

Systems, devices, and methods are provided for inserts and orthopedic blocks adapted to receive the inserts. The orthopedic blocks include one or more voids, each having a plurality of receiving portions configured to receive a cutting insert, a sleeve insert, any other suitable orthopedic inserts, or any combination thereof. The inserts include an outer surface that is configured to couple with the receiving portions. In certain embodiments, the inserts are removably coupled to the orthopedic blocks. In certain embodiments, the inserts are integrally provided on the orthopedic blocks or other components. Metal inserts provided in polymer orthopedic blocks can reduce the amount of wear debris compared to wear debris which would occur from a cutting instrument contacting the polymer block directly.

Description

ORTHOPEDIC BLOCK INSERTS

Cross- eference to Related Application

[0001] This application claims the benefit of United States Provisional Patent Application No. 61/373,973, filed August 16, 2010, and United States Provisional Patent Application No. 61/373,986, filed August 16, 2010, which are hereby incorporated by reference herein in their entireties.

Background

[0002] Disposable custom cutting blocks are typically manufactured using plastic materials for cost savings and environmental concerns. However, because plastic materials are substantially softer than a steel cutting blade, a substantial amount of wear debris can be generated during orthopedic surgery. Debris left in the joint capsule/cavity can position between articulating surfaces and cause detrimental wear on the implanted prosthesis.

Furthermore, patients can experience negative biological responses to plastic wear debris.

[0003] Typical custom cutting blocks also do not provide modularity or adjustment options during surgical procedures. For example, the cutting blocks include cutting slots and guide pin placements that are permanently positioned within the cutting block. Accordingly, a surgeon's only intra-operative "bailout option" for the custom cutting block is to discard the block and continue the surgery with conventional off-the-shelf instruments. Even surgeries using custom cutting blocks still require a readily available instrument kit of conventional cutting blocks that correspond to a standard implant sizes rather than the specific patient.

Mechanical alignment is an important feature of orthopedic cutting blocks. However, custom cutting blocks and conventional cutting blocks are not modified intra-operatively and therefore modifications during the surgery require that separate blocks be used.

Summary

[0004] Disclosed herein are systems, devices, and methods for providing inserts, such as cutting inserts and sleeve inserts, and orthopedic blocks that receive the inserts, such as cutting blocks and guide blocks. The inserts include an outer surface that is configured to couple with a plurality of receiving portions on an orthopedic block. In certain embodiments, the inserts are removably coupled to the orthopedic blocks. In certain embodiments, the inserts are integrally provided on the orthopedic blocks or other components, yet can still be adjustably positionable therein. The orthopedic block has at least one void that includes a plurality of receiving portions that receive the inserts. A void may be provided for receiving cutting inserts or sleeve inserts. The inserts can provide a surgeon with the opportunity to install an orthopedic block first and then change the inserts intra-operatively as desired.

[0005] The orthopedic blocks described herein are preferably patient-matched to the particular anatomy of a patient, and in certain embodiments, at least a portion of the inserts are patient-matched. Patient-matched instruments help the surgeon achieve more optimal implant alignment, custom to the patient's unique knee anatomy. Conventional cutting blocks are typically sized and shaped to correspond to a standard implant size, having cutting slots that are permanently positioned within the cutting block, whch in many uses does not optimally fit the patient's bone size or other features. The surgeon accordingly chooses such cutting blocks based on the measured size of the bone. With patient-matched instruments and guides, however, a patient's anatomy including the knee system may be imaged using a standard imaging technology such as X-ray, Magnetic Resonance Imaging (MRI), CT scanning, or any other suitable imaging technology. This imaging data can then be imported into a computer-aided design (CAD) or similar system and used as the basis for developing a multi-dimensional digital model of the patient's anatomy of interest through segmentation and other processing procedures. Surgical instruments and guides can then designed and built, mapping out specific bone cuts to accurately align the implants that will be placed into the patient's knee.

[0006] In certain embodiments, orthopedic blocks such as plastic disposable cutting blocks are formed by printing them and then including disposable metal inserts made to assemble into the blocks. The disposable metal inserts may be formed by casting, forging, stamping, any other suitable process, or any combinations thereof. Rather than printing the block with final pin hole positioning dimensions or final cutting slot dimensions, larger voids are created. The larger voids are configured to receive the metal inserts, which are, for example, pressed into the voids. The metal inserts serve as the actual bearing surface and reduce wear debris compared to wear debris which would occur from a cutting instrument contacting the plastic block directly. The modular cutting blocks described above would be fully assembled by the time the surgeon received the block and could be thrown away after the procedure. [0007] In certain embodiments, generally permanent or non-disposable metal inserts, such as inserts that would stay in the field through loaner kits, for example, may be provided. The permanent metal inserts are configured to be used in several different cases if properly processed (e.g., sterilized) between cases. In this regard, several different inserts can be made to go into a standard void size. Not only would the harder material of the insert reduce cutting block debris, but by providing a plurality of metal inserts having different cutting slot and pin hole configurations, some intra-operative adjustments can be made, such as changing the angle or depth of cuts or changing the location or direction of a pin hole.

[0008] In certain implementations, a surgeon places a custom, patient-matched cutting block on a patient's bone until it rests in all degrees of freedom against a patient's bone and cartilage. Next, the surgeon inserts a "zero-degree posterior slope" metal cutting slot insert into a standard void provided in the plastic cutting block. The surgeon then makes the distal femoral cut. If, during surgery, it is determined that not enough posterior bone has been removed, the surgeon can remove the "zero-degree posterior slope" metal cutting slot insert from the plastic cutting block and introduce a "three-degree posterior slope" metal cutting slot insert, or any other suitable insert, into the same standard void provided in the plastic cutting block. The surgeon may then re-cut the distal femoral cut. Throughout surgery, the set of generally permanent or non-disposable metal inserts provides a surgeon with intraoperative "bailout options."

[0009] Similarly, pin holes may be angled or offset using metal inserts such as sleeve inserts. The pin holes may be used for securing the cutting block to the bone or for setting rotational alignment for the prosthesis to be implanted. In certain implementations, a surgeon places a custom, patient-matched plastic cutting block on a patient's bone until it rests in all degrees of freedom against a patient's bone and cartilage. Next, the surgeon inserts "zero- offset, zero-degree" metal drill guide inserts into standard voids in bosses provided on the plastic cutting block. The surgeon then places a gauge into the two holes to ensure that the femoral rotation is aligned, for example, with the transepicondylar axis and perpendicular to the anterior-posterior anatomic reference line. If, during surgery, it is determined that more external rotation is needed, the surgeon can remove one or both of the "zero-offset, zero- degree" metal drill guide inserts from the plastic cutting block and introduce one or more eccentric "medium offset, zero-degree" metal drill guide inserts, or any other suitable inserts, into the same standard void or voids provided in the plastic cutting block. The surgeon can then reassess femoral rotation using the gauge, and then drill the rotation holes which will set the femoral internal-external rotation. Throughout surgery, the set of generally permanent or non-disposable metal inserts provides a surgeon with intra-operative "bailout options."

[0010] In certain embodiments, conventional or standard metal cutting blocks, such as a standard sized distal femoral cutting block, may be imbedded within, housed within, or otherwise attached to a custom patient-matched cutting block via suitable attachment means that may also be adjustable.

[0011] Systems, devices, and methods described herein provide inserts and orthopedic blocks that receive the inserts. In certain embodiments, an orthopedic cutting block includes a void having a plurality of receiving portions, each receiving portion configured to receive a cutting insert. The receiving portions can be adjustable, removably positionable within the void, or both. In certain embodiments, the cutting block includes a contact surface having at least one patient-matched contour structured to mate with an opposing feature of a patient's anatomy. Each receiving portion is positioned in a different location relative to the void. In some embodiments, the position of at least one receiving portion is predetermined according to patient-matched data.

[0012] In certain embodiments, the orthopedic cutting block includes a cutting insert comprising a cutting slot having a cutting alignment and an outer surface removably coupled with one of the plurality of receiving portions. The orthopedic cutting block and the cutting insert can be formed of different materials. The outer surface is configured to removably couple with one or more of the plurality of receiving portions, and the cutting alignment can be offset from the center of the void or directed at an angle with respect to the void. The cutting insert may serve as a bearing surface and the outer surface may be correspondingly shaped with an inner surface of the void. In particular, the outer surface can be tapered, splined, or keyed to a complimentary key on an orthopedic block. In certain embodiments, the cutting insert or the orthopedic cutting block includes an attachment portion for removably attaching a drop rod. The cutting insert can also include a fluid channel.

[0013] In certain embodiments, a method of selecting a cutting block insert includes sequentially placing at least two inserts in a cutting block, each insert comprising a cutting slot having a respective predetermined cutting angle, evaluating an acceptance criteria of each insert relative to patient-specific data, determining a preferred cutting angle based on the evaluation of the acceptance criteria, and selecting an insert corresponding to the determined cutting angle. The patient-specific data includes data indicative of one or more specific features of a patient's anatomy. The method can further include attaching a drop rod to a connecting portion of the selected insert and visually and tactilely confirming an alignment position of the cutting block using the drop rod, where the drop rod can be extended from a first position to an extended position. In certain embodiments, visually confirming an alignment position includes viewing the alignment position through a transparent window set in the cutting block. In certain embodiments, the method further includes determining a preferred cutting depth based on the evaluation of the acceptance criteria and selecting an insert corresponding to the determined cutting depth.

[0014] In certain embodiments, a kit is provided that includes a plurality of orthopedic block inserts, each comprising an outer surface that removably couples with a void in an orthopedic block, and a cutting slot configured to provide a cutting alignment that is offset from the center of the void or directed at an angle with respect to the void, wherein each respective one of the plurality of orthopedic block inserts has a respective cutting alignment. The kit also includes at least one orthopedic block insert comprising a cutting slot configured to provide a cutting alignment in the center of the void.

[0015] Systems, devices, and methods described herein provide inserts and orthopedic blocks that receive the inserts. In certain embodiments, a sleeve insert includes a through- hole for receiving a pin and an outer surface configured to removably couple with a plurality of receiving portions disposed in a void of an orthopedic cutting block. The through-hole is configured to be offset from the center of the void or directed at an angle with respect to the void, and more than one through-hole can be provided in the sleeve insert. The sleeve insert may serve as a bearing surface and the outer surface may be correspondingly shaped with an inner surface of the void. In particular, the outer surface can be tapered, splined, or keyed to a complimentary key on an orthopedic block. In certain embodiments, the sleeve insert includes an attachment portion for removably attaching a drop rod. The sleeve insert can also include a fluid channel.

[0016] In certain embodiments, an orthopedic block includes a void having a plurality of receiving portions and a sleeve insert removably coupled with one of the receiving portions. The orthopedic block can further include a contact surface having at least one patient- matched contour structured to mate with an opposing feature of a patient's anatomy. In certain embodiments, each receiving portion is positioned in a different location relative to the void. In certain embodiments, the position of at least one receiving portion is

predetermined according to patient-matched data. The orthopedic block and the sleeve insert can be formed of different materials. The orthopedic block can include a plurality of voids, each void configured to receive a respective sleeve insert, and the orthopedic block can further include a transparent window and a drop rod. [0017] In certain embodiments, a method of selecting an orthopedic block insert includes sequentially placing at least two sleeve inserts in an orthopedic block, each insert comprising a through-hole for receiving a pin, evaluating an acceptance criteria of each insert relative to patient-specific data, determining a preferred pin orientation based on the evaluation of the acceptance criteria, and selecting an insert corresponding to the determined pin orientation. The patient-specific data includes data indicative of one or more specific features of a patient's anatomy. The method can further include securing the orthopedic block to a patient's joint, fastening a pin to the patient's joint, wherein the pin is positioned in the preferred pin orientation using the selected insert, removing the orthopedic block from the patient's joint, wherein the pin remains fastened to the patient's joint; and placing a cutting block over the pin, the cutting block having an insert within which the pin is positioned. The method can further include attaching a drop rod to a connecting portion of the selected insert and visually and tactilely confirming an alignment position of the cutting block using the drop rod, where the drop rod can be extended from a first position to an extended position. In certain embodiments, visually confirming an alignment position includes viewing the alignment position through a transparent window set in the orthopedic block.

[0018] In certain embodiments, a kit is provided that includes a plurality of orthopedic block inserts, each comprising an outer surface that removably couples with a void in an orthopedic block, and a through-hole for receiving a pin, the through-hole configured to be offset from the center of the void or directed at an angle with respect to the void, wherein each respective one of the plurality of orthopedic block inserts has a respective offset from the center of the void or an angle with respect to the void. The kit also includes at least one orthopedic block insert comprising a zero-offset and zero-angle through-hole.

[0019] Variations and modifications of these embodiments will occur to those of skill in the art after reviewing this disclosure. The foregoing features and aspects may be implemented, in any combination and subcombinations (including multiple dependent combinations and subcombinations), with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated in other systems. Moreover, certain features may be omitted or not implemented. Brief Description of the Drawings

[0020] The foregoing and other objects and advantages will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: [0021] FIG. 1 shows a front perspective view of an illustrative orthopedic block;

[0022] FIG. 2 shows a side elevation view of the illustrative orthopedic block of FIG. 1;

[0023] FIG. 3 shows a bottom plan view of the illustrative orthopedic block of FIG. 1;

[0024] FIG. 4 shows a back perspective view of the illustrative orthopedic block of FIG. 1;

[0025] FIGS. 5-7 show various perspective views of illustrative cutting inserts and front elevation views of an orthopedic block having the illustrative cutting inserts received therein;

[0026] FIGS. 8 and 9 show various front elevation views of orthopedic blocks having illustrative receiving portions and cutting inserts coupled thereto;

[0027] FIGS. 10 and 11 show various front elevation views of orthopedic blocks having illustrative adjustable receiving portions;

[0028] FIG. 12 shows a front elevation view of an illustrative orthopedic block;

[0029] FIG. 13 shows a perspective view of an illustrative sleeve insert and a bottom plan view of an illustrative orthopedic block having sleeve inserts and an optional viewing window;

[0030] FIG. 14 show a cross-sectional view of an illustrative sleeve insert from FIG. 13, taken along line A-A;

[0031] FIGS. 15-17 show various cross-sectional views of illustrative sleeve inserts;

[0032] FIG. 18 shows a schematic view of an illustrative insert and taper junction;

[0033] FIG. 19 shows a schematic view of an illustrative insert having instrumentation features;

[0034] FIGS. 20-22 show schematic views of various illustrative voids for receiving an insert;

[0035] FIGS. 23-25 show schematic views of illustrative receiving portions and sleeve inserts coupled thereto;

[0036] FIG. 26 shows a front elevation view of an illustrative multi-piece orthopedic block;

[0037] FIG. 27 shows a front exploded view of the illustrative multi-piece orthopedic block of FIG. 26; and

[0038] FIG. 28 shows a front elevation view of an illustrative orthopedic block. Detailed Description

[0039] To provide an overall understanding of the systems, devices, and methods described herein, certain illustrative embodiments will be described. Although the embodiments and features described herein are specifically described for use in connection with orthopedic knee replacement systems, it will be understood that all the components, connection mechanisms, adjustable systems, manufacturing methods, and other features outlined below may be combined with one another in any suitable manner and may be adapted and applied to medical devices and implants to be used in other surgical procedures, including, but not limited to acetabular procedures, spine arthroplasty, cranio-maxillofacial surgical procedures, hip arthroplasty, shoulder arthroplasty, as well as foot, ankle, hand, and other extremity procedures.

[0040] FIG. 1 shows a front perspective view of an illustrative orthopedic block. As shown in FIG. 1, for example, orthopedic block 100 is a cutting block that includes an anterior portion 102, a base portion 104, and a distal portion 106. Included in the base portion 104 is a void 110 having a height 112. The void 110 of base portion 104 may have any suitable height 1 12 for receiving an insert such as a cutting insert. Although the void 110 shown in FIG. 1 has a shape that is substantially rectangular, it will be understood that void 110 may have any suitable shape or combinations thereof for receiving an insert. The orthopedic block 100 is shown coupled to a patient's femur 130. In particular, the orthopedic block 100 is located at the distal and anterior end of the femur 130, between the condyles at the end of the femur 130. The orthopedic block 100 may be used by a surgeon for making a distal cut on the end of the femur 130 in preparation for installing a femoral implant (but may also be configured for making anterior, posterior, distal, or chamfer cuts, or any combination thereof, on the end of the femur 130 to shape the end of the bone, for example, to match the shape of a femoral implant). In certain embodiments, a fluid channel 128 may be provided on the orthopedic block 100 for fluid suction during surgical procedures. The fluid channel 128 is shown as being positioned on the base portion 104, but may be provided at any suitable location on the orthopedic block 100.

[0041] The void 110 receives an insert such as, for example, a cutting insert that acts as the bearing surface for a cutting instrument. A cutting insert provides a surgeon with the option of using various modular configurations during surgery to alter the location of a cut. For example, cutting inserts placed into the void 110 may have one or more cutting slots disposed at an angle or offset with respect to the void 110. A cutting insert may be removably placed into the void 110 or may be permanently provided within the void 110. Removable cutting inserts may be selected from a kit of inserts prior to or during surgery.

[0042] As shown in FIG. 1, the orthopedic block 100 also includes a number of anterior boss portions 108 disposed on the anterior portion 102 of the orthopedic block 100. Anterior boss portions 108 include a void 109, centrally located therein, for receiving an insert such as a sleeve insert that acts as the bearing surface for a pin that secures the block to a patient's bone. A sleeve insert includes a through-hole for receiving a pin to affix the orthopedic block 100 to the femur 130. The anterior boss portions 108 are shown for receiving a pin in an anterior-to-posterior direction through the femur 130. The sleeve inserts that are placed into the voids 109 may have any suitable number of through-holes at any suitable angle or offset with respect to the respective void in which the sleeve insert is positioned. A sleeve insert may be removably placed into the voids 109 or may be permanently provided within a void 109. In certain embodiments, sleeve inserts may be permanently provided within some voids 109, and other removable sleeve inserts may be provided in other voids 109.

[0043] The orthopedic block 100 also includes one or more distal boss portions 114 disposed on the distal portion 106 of the orthopedic block 100. Similar to the anterior boss portions 108, the distal boss portions 114 include a void 115 therethrough for receiving an insert such as a sleeve insert that acts as the bearing surface for pins used to affix the orthopedic block 100 to the patient's femur 130. The distal boss portions 114 receive pins in an inferior-to-superior direction through the femur 130. When a surgeon inserts pins aligned in the directions provided by anterior boss portions 108 and distal boss portions 114, it substantially prevents the orthopedic block 100 from translating or rotating during the procedure. The voids 109 of the anterior boss portions 108 and the voids 115 of the distal boss portions 114 are shown as being substantially elliptical. However, it will be understood that the voids 109 and 115 may have any suitable shape or combinations thereof for receiving an insert. Similarly, the anterior boss portions 108 and 114 through which the voids 109 and 115 extend may have any suitable shape.

[0044] FIG. 2 shows a side elevation view of the orthopedic block 100 of FIG. 1. As shown in FIG. 2, the inner surface of the orthopedic block 100 contacts the femur 130 at an interface 120. In order to position the orthopedic block 100 securely against the patient's femur prior to resecting the bone, the orthopedic block is preferably patient-matched to the patient's specific anatomy. The inner surface of the orthopedic block 100 mates with the patient's femur along one or more contact regions in the interface 120. As shown in FIG. 2, the void 110 of base portion 104 has a depth, d, along which an insert may be positioned. The void 110 extends fully through the orthopedic block 100. In particular, the void 110 extends from the outer anterior surface of the base portion 104 to an inner surface of the base portion 104 at the interface 120 with the femur 130. The depth, d, of the void 110 therefore depends on the dimensions of the orthopedic block, which may be determined based on a particular patient's anatomy. Similarly, the voids 109 and 115 of the boss portions 108 and 114 have a depth that extends through the orthopedic block 100 until contacting the femur 130.

[0045] FIG. 3 shows a bottom plan view of the orthopedic block 100 of FIG. 1 and includes the distal boss portions 114 located on the distal portion 106 of the orthopedic block 100 such that the movement of the orthopedic block 100 is substantially restricted during the surgical procedure. Although three distal boss portions 114 are shown, it will be understood that any suitable number of boss portions may be used.

[0046] FIG. 4 shows a back perspective view of the orthopedic block 100 of FIG. 1 according to some embodiments, and includes anterior portion 102, base portion 104, and distal portion 106. As can be seen in FIG. 4, the inner surface of the orthopedic block 100 includes contact regions 140, 142, and 144 along interface 120, where contact regions 140, 142, and 144 are substantially shaped to match a patient's anatomy. In particular, contact region 140 is shaped to correspond to a first condyle of the femur 130, contact region 142 is shaped to correspond to a second condyle of the femur 130, and contact region 144 is shaped to match the intercondylar fossa of the femur 130, which is located between the two condyles at the distal end of the femur 130. The first condyle received by contact region 140 may be either the lateral or medial condyle, and the second condyle received by contact region 142 is thus the other of the lateral or medial condyles.

[0047] Also shown in FIG. 4 is void 110 extending from the outer anterior surface of the base portion 104 to an inner surface of the base portion 104 at the interface 120 with the femur 130. As discussed above, the void 110 of orthopedic block 100 is configured to receive an insert such as a cutting insert for making, for example, a distal cut in the patient's anatomy.

[0048] FIGS. 5-7 show various perspective views of cutting inserts and front elevation views of an orthopedic block having the cutting inserts received therein. The orthopedic block 200 includes an anterior portion 202, a base portion 204, and a distal portion 206. A void 210 is disposed in the base portion 204 and receives the cutting inserts. As shown in FIG. 5, a cutting insert 250 includes, a front surface 251, a cutting slot 252 provided on the front surface 251, and an outer surface 254 that mates with an inner surface of the void 210. The cutting insert 250 has a depth which is illustrated as di. The depth, di, of the cutting insert 250 can be any suitable depth up to and including the depth of the void into which the cutting insert 250 is placed (such as depth, d, of the void 110 shown in FIG. 3) or can be greater than the depth of the void such that the cutting insert extends out of the orthopedic block. In certain embodiments, at least a portion of the cutting insert, such as cutting insert 250, may contact the patient's bone and, in some instances, the contacting portion of the cutting insert may be patient-matched. The cutting slot 252 is shaped to receive, and acts as a bearing surface for, a cutting instrument or blade. As shown in FIG. 5, the cutting slot 252 has a substantially rectangular profile, although any suitable shape can be provided. The cutting slot 252 can be provided at any location on the front surface 251 of the cutting insert 250. For example, cutting slot 252 is located in the center of the front surface 251. The cutting slots 262 and 272 of FIGS. 6 and 7, respectively, are at different locations and are offset from the center of the front surfaces of the respective cutting inserts. Alternatively, or additionally, the cutting slot 252 can orientated at an angle with respect to an axis defined by the medial-lateral direction. Furthermore, the cutting slot can be oriented at an angle with respect to an axis along the depth, di, of the cutting insert 250. This axis may be substantially parallel to the anterior-posterior direction.

[0049] The cutting insert 250 is inserted into orthopedic block 200 as shown in FIG. 5. In particular, the cutting insert 250 is placed into the void 210 of the base portion 204 of the orthopedic block 200. As shown in FIG. 5, the cutting slot 252 is displaced at a height, hi, relative to the upper edge of the void 210. The desired height of the cutting slot with respect to the orthopedic block {e.g., height hi) may be determined based on patient-specific data. For example, the surgeon may select a cutting insert having particular cutting slot dimensions or other dimensions based on reviewing patient-specific data.

[0050] FIG. 6 shows a cutting insert 260 having a cutting slot 262 and an outer surface 264 that mates with an inner surface of the void 210 of orthopedic block 200. The cutting insert 260 has a depth which is illustrated as <¾ and may be any depth up to and including the depth of the void into which the cutting insert 260 is placed, or can be greater than the depth of the void such that the cutting insert extends out of the orthopedic block. The cutting slot 262 of cutting insert 260 is offset relative to the cutting slot 252 of cutting insert 250. When the cutting insert 260 is placed into the orthopedic block 200 as shown in FIG. 6, the cutting slot 262 is displaced at a height, /ζ₂, from the upper edge of the void 210 that is relatively less than the height, hi, of the cutting slot 252 shown in FIG. 5.

[0051] FIG. 7 shows a cutting insert 270 having a cutting slot 272 and an outer surface 274 that mates with an inner surface of the void 210 of orthopedic block 200. The cutting insert 270 has a depth which is illustrated as t¾ and may be any depth up to and including the depth of the void into which the cutting insert 270 is placed, or can be greater than the depth of the void such that the cutting insert extends out of the orthopedic block. The cutting slot 272 of cutting insert 270 is offset relative to the cutting slot 252 of cutting insert 250. When the cutting insert 270 is placed into the orthopedic block 200 as shown in FIG. 7, the cutting slot 272 is displaced at a height, h₃, from the upper edge of the void 210 that is relatively greater than height, hi, of the cutting slot 252 shown in FIG. 5 and the height, of the cutting slot 262 shown in FIG. 6.

[0052] In certain embodiments, cutting inserts 250, 260, and 270 may be provided as a kit for use during surgical procedures. For example, a surgeon may select cutting insert 250, having a cutting slot that is substantially in the center of the void 210. During the procedure, the surgeon may discover imperfections in the orthopedic block 200 or imperfections in the patient's femur that were previously unknown or previously unaccounted for, and may decide to replace the cutting insert 250 with cutting insert 260. The relative difference in height between hi and /? may thus be preferable for making, for example, a distal cut in the patient's femur. Such modular cutting inserts may allow the surgeon to have numerous options when performing surgery.

[0053] The cutting inserts described herein include an outer surface that mates with an interior surface of a void in an orthopedic block. For example, outer surface 254, outer surface 264, and outer surface 274 are configured to couple with the interior surface of the void 210 of the orthopedic block 200. In certain embodiments, this may be accomplished via receiving portions that are disposed in a void of an orthopedic cutting block. Receiving portions that couple with the outer surface of an insert are described in more detail with reference to FIGS. 8-11.

[0054] FIG. 8 shows an orthopedic block 300 having a plurality of receiving portions. For example, orthopedic block 300 includes a first rim 320 and a second rim 322, adapted to receive a cutting insert. In particular, the first rim 320 and the second rim 322 define a plurality of insert positions 312, 314, 316 within the void 310. As shown in FIG. 8, a cutting insert 302 having cutting slot 304 is placed into the first position 312 of the orthopedic block 300. The cutting insert 302 may be removably placed within the first position 312. In this case, rather than modifying the position of a cutting slot by selecting from numerous cutting inserts as shown in FIGS. 5-7, a surgeon may remove the cutting insert 302 from the first position 312 and place the cutting insert 302 in a second position 314 or a third position 316. For example, in some embodiments, the first position 312 may substantially correspond to the cutting slot position of FIG. 6, the second position 314 may substantially correspond to the cutting slot position of FIG. 5, and the third position 316 may substantially correspond to the cutting slot position of FIG. 7. [0055] It will be understood that any suitable number of receiving portions, such as first and second rims 320 and 322, may be disposed within a void of an orthopedic block. For example, as shown in FIG. 9, orthopedic block 350 includes a rim 370 within the void 360 that defines a first position 362 and a second position 364. In some embodiments, the insert positions defined by the receiving portions of an orthopedic block receive cutting inserts having different dimensions. For example, the first position 362 of orthopedic block 350 has a relatively greater height than the second position 364 of the block 350 and the cutting insert 352 having cutting slot 354 may not fit within the second position 364. In certain

embodiments, the cutting slot 354 of the cutting insert 352 itself has any suitable height. For example, the cutting slot 354 shown in FIG. 9 has a relatively greater height than the cutting slot 304 of FIG. 8. In some embodiments, despite the relatively different size of cutting insert 302 and cutting insert 352, the cutting slot 354 of the cutting insert 352 may nonetheless have substantially the same dimensions as the cutting slot 302 of the cutting insert 302.

[0056] In embodiments where the cutting inserts take up substantially the entire area of the void within an orthopedic block, the receiving portions such as, for example, first and second rims 320 and 322 of FIG. 8 and rim 370 of FIG. 9, may be instead be provided as recesses within the interior surface of a void and the cutting inserts may have protrusions on the periphery of the outer surface such that when the insert is received within the void, the recessed receiving portions mate with the protrusions on the outer surface of the cutting insert.

[0057] In some embodiments, the receiving portions of an orthopedic block are adjustable. As shown in FIG. 10, for example, orthopedic block 400 includes an adjustable rim 420 having a rotatable portion 422. The adjustable rim 420 defines two insert positions 412, 414 within the void 410. In particular, the adjustable rim defines a first position 412 and a second position 414. The adjustable rim 420 of FIG. 10 may be adjusted using any suitable technique. For example, a through hole may be provided in the side of the orthopedic block 400 through which a tool is inserted in order to mate with and rotate the rotatable portion 422 of the adjustable rim 420. For example, a screw may mate with a correspondingly shaped indent on the rotatable portion 422 in order to adjust the adjustable rim 420 and thereby create an angle at which a cutting instrument is placed into a cutting insert. In this way, a cutting insert having a cutting slot with no angular offset can be used to make angled cuts on a patient's anatomy. [0058] As discussed above, in some embodiments the cutting insert itself has a cutting slot that is angled such that when the cutting insert is placed into an orthopedic block, such as the orthopedic blocks shown in FIGS. 5-9, the outer surface of the cutting insert may be substantially straight and mate with the void within an interior surface of the void, yet the cutting slot may be angled with respect to the void.

[0059] FIG. 11 shows an orthopedic block 450 having a first removable rim 470, a second removable rim 472, and a third removable rim 474 within void 460. Each of the removable rims 470, 472, 474 includes a mateable member, such as mateable member 471, that is disposed into a side of the void 460. The rims 470, 472, 474 may be removed, repositioned, or otherwise adjusted to create one or more insert positions. For example, as shown in FIG. 11, the three removable rims 470, 472, and 474 define four insert positions within the void 460: first position 462, second position 464, third position 466, and fourth position 468. If rim 470 is removed, the remaining rims 472 and 474 would define three insert positions, and as further rims are removed fewer insert positions would remain. In this way, the orthopedic block 450 has a modular number of positions that can be created by adding or removing the rims 470, 472, 474. Furthermore, the size of the insert positions can be adjusted based on removing or inserting the removable rims 470, 472, 474. For example, if rim 470 is removed, the insert position created (i.e., the combination of first position 462 and second position 464) would be relatively larger than the remaining third position 466 and fourth position 468. Although three removable rims 470, 472, 474 are shown in FIG. 11, it will be understood that any suitable number of removable rims may be provided.

[0060] Although orthopedic blocks 300, 350, 400, and 450 have been described as including receiving portions that are rims, it will be understood that any suitable receiving portions may be included in the void for receiving an insert such as a cutting insert. For example, in some embodiments, the receiving portions are provided as ribs disposed on the interior surface of the void of the orthopedic block such that the ribs contact the insert and make a frictional engagement with the insert while allowing the insert to be later removed.

[0061] In some embodiments, the orthopedic block includes more than one void for receiving a cutting insert. For example, as shown in FIG. 12, orthopedic block 500 includes anterior portion 502, base portion 504, and distal portion 506. The orthopedic block 500 further includes a first void 510 and a second void 511 disposed on the base portion 504. The orthopedic block 500 may be similar to the orthopedic block 100 of FIG. 1, and the first void 510 and the second void 511 may therefore be relatively smaller than the void 110 of FIG. 1 in order to fit on the base portion 504. In some embodiments, the base portion 504 may be sized to fit a plurality of voids that are substantially the same size as the void 110 of FIG. 1. For example, the base portion 504 may be relatively larger than the base portion 104 of FIG. 1, such that the first void 510 may be substantially the same size as void 110 and the second void 511 may be substantially the same size as void 110. In some embodiments, the first void 510 may be a different size relative to the second void 511. Although only two voids are shown in FIG. 12 it will be understood that three or more voids may be provided.

Furthermore, the voids may be provided on any suitable portion of the orthopedic block. For example, voids for receiving cutting inserts may be disposed on the distal portion 506 of the orthopedic block 500.

[0062] As shown in FIG. 12, the orthopedic block 500 also includes anterior boss portions 508 disposed on the anterior portion 502 and distal boss portions 514 disposed on the distal portion 506. Although five boss portions 508, 514 are shown, it will be understood that any suitable number of boss portions may be provided for receiving any suitable number of sleeve inserts therein. In certain embodiments, a fluid channel 528 may be provided on the orthopedic block 500 for fluid suction during surgical procedures. Although the fluid channel 528 is shown as being positioned on the base portion 504, fluid channels may be provided at any suitable location on the orthopedic block 500.

[0063] The inserts that have been thus described have been primarily directed to cutting inserts that are received by a cutting void, such as cutting inserts 250, 260, 270 received by void 210 of orthopedic block 200. However, inserts may also be provided as sleeve inserts that may be received within the voids of the boss portions of the orthopedic block. FIG. 13 shows a perspective view of a sleeve insert and a bottom plan view of an orthopedic block according to certain embodiments. The orthopedic block 550 of FIG. 13 may be similar to the orthopedic block 100 shown in FIG. 3. The orthopedic block 550 includes three sleeve inserts 560, 563, 565 disposed within the voids of three distal boss portions 551, 553, 555 on the distal portion 556 of the orthopedic block 550. The sleeve inserts, such as sleeve insert 560, include a through-hole 562 provided on the front surface 561 and an outer surface 564 that is configured to removably couple with an inner surface of the void of distal boss portion 551, for example, at a plurality of receiving portions disposed in the void of the distal boss portion 551. Sleeve insert 560 has a depth, d_si, that can be any suitable depth up to and including the depth of the void into which the sleeve insert 560 is placed, or can be greater than the depth of the void such that the sleeve insert extends out of the orthopedic block. In certain embodiments, at least a portion of the sleeve insert, such as sleeve insert 560, may contact the patient's bone and, in some instances, the contacting portion of the sleeve insert may be patient-matched.

[0064] FIG. 14 shows a cross-sectional view of the sleeve insert 560 of FIG. 13, taken along line A-A. As shown in FIG. 14, for example, the through-hole 562, extends throughout the entire depth, <¾, of the sleeve insert 560 such that a pin may be placed within the through- hole. The through-hole may be provided at any suitable angle and at any suitable offset with respect to the distal boss portions as shown in FIGS. 15-17. For example, sleeve insert 570 includes a through-hole 572 extending throughout the depth of the sleeve insert 570 and angled at an angle θι with respect to a longitudinal axis of the void. Sleeve insert 580 includes a through-hole 582 at an angle Θ₂ with respect to a longitudinal axis of the void. Sleeve insert 590 includes a through-hole 592 extending throughout the depth of the sleeve insert 590 and at an offset, h, from the center of the sleeve insert 590. Although each of the through-holes is shown as having a substantially similar diameter, it will be understood that any suitable diameter may be provided and may be determined according to the pins used for securing the orthopedic block to the patient's femur.

[0065] Returning to FIG. 13, the orthopedic block 550 also includes a transparent window 552. The window 552 may take up any suitable area of the orthopedic block 550 and may be provided so that the surgeon has a visual indication of the fit of the orthopedic block 550. The fit of the orthopedic block can be important for ensuring that the cuts are made correctly with respect to the patient's anatomy. Windows enable a surgeon to visualize whether or not the orthopedic block is properly seated on the patient's bone and cartilage. Although the transparent window 552 is shown as being located on the distal portion 556 of the orthopedic block 550, it will be understood that the transparent window 552 can be provided at any suitable location on the orthopedic block. For example, a transparent window such as window 552 could be located on an anterior portion or base portion of an orthopedic block, such as anterior portion 102 and base portion 104 of the orthopedic block 100 shown in FIG. 1. The transparent window 552 is shown as being on the distal portion 556 of the orthopedic block 550 because that region provides a desirable view of the femur where the distal cut will be made by the surgeon.

[0066] FIG. 18 shows a schematic view of an illustrative insert and taper junction according to some embodiments. A metal insert 602, including a through-hole or cutting slot 604, has a tapered outer surface 606 that is configured to mate with a correspondingly shaped tapered junction 612 of a boss 610. In certain embodiments, the boss 610 may correspond to distal boss portions 114 or anterior boss portions 108 of FIG. 1 for receiving sleeve inserts. In certain embodiments, the boss 610 may correspond to the void 110 of FIG. 1 for receiving a cutting insert. In particular, it may be desirable to have a boss that projects from the orthopedic block about a void in order to increase the depth of the void into which the insert, such as a cutting insert, is placed. The greater depth of a cutting insert can provider greater stability for a cutting instrument. In certain embodiments, even where a boss portion is not provided, an insert such as a cutting insert or sleeve insert may have a depth that is greater than the depth of the void into which it is placed to provide, for example, greater stability for a cutting instrument.

[0067] FIG. 19 shows a schematic view of an insert having instrumentation features. For example, as shown in FIG. 19, an insert 652 includes additional guide and instrumentation features such as drop rod access or attachment portion 658 for receiving a drop rod. The insert 652 includes a through-hole or cutting slot 654 and a tapered outer surface 656 that mates with a correspondingly shaped taper junction 662 of boss 660. As discussed above, the boss 660 can be provided as a boss about a void for receiving sleeve inserts, cutting inserts, or any other suitable inserts. A drop rod can be used by the surgeon as a visual check to enable the surgeon, for example, to verify the alignment of the orthopedic block. In some embodiments, the drop rod may be received directly on the orthopedic block rather than, or in addition to, being received by the attachment portion 658 of the insert 652. That is, the drop rod can be removably attached to the insert 652 and can be removably attached to the orthopedic block independently of the insert. Drop rod access or attachment portion 658 is provided on a protrusion of insert 652 and has a hole therethrough that extends perpendicular to a plane of the void formed with the orthopedic block. Other suitable means may be used for attaching a drop rod, such as a clamping arm extending from an anterior portion of the orthopedic block which is configured to frictionally engage an outer diameter of a drop rod. In certain embodiments, the drop rod may be an extendable telescoping drop rod.

[0068] FIGS. 20-22 show a schematic views of voids for receiving an insert. The block segments 700, 710, 720 shown with respect to FIGS. 20-22 receive sleeve inserts, although it will be understood that the concepts herein apply also to cutting inserts or any other suitable inserts. Block segment 700 includes a void 702 and a spline portion 704. The spline portion 704 is provided on the interior surface of the void 702 and is shaped to mate with a correspondingly shaped spline on the outer surface of an insert. Block segment 710 has a key portion 714 disposed on an inner surface of the void 712. An insert such as a sleeve insert may be provided with a key on the outer surface of the insert that is shaped to mate with the key portion 714. The sleeve inserts may be splined or have key portions on their outer periphery to increase surface area contact with the interior surface of the void and reduce the possibility of separation during high vibrations typically experienced with use. Keys and splines may also allow drill guides to be offset without changing the distance between drill holes. Block segment 720 shows a void 722 having a taper portion 724 such as the taper junctions 612, 662 shown on the boss 610 of FIG. 18 and the boss 660 of FIG. 19, respectively. Each insert may have one of the foregoing outer surface configurations, or any other suitable configuration, in order to removably couple with a void in an orthopedic block as demonstrated by block segments 700, 710 and 720.

[0069] The sleeve inserts described herein include an outer surface that mates with an interior surface of a void in an orthopedic block. For example, outer surface 564 is configured to couple with the interior surface of the void of the orthopedic block 550. In certain embodiments, this may be accomplished via receiving portions that are disposed in a void of an orthopedic cutting block. The receiving portions for use with sleeve inserts may be substantially similar to the receiving portions discussed above in connection with cutting inserts. Receiving portions that couple with the outer surface of an insert are described in more detail with reference to FIGS. 23-25, which show schematic views of orthopedic block segments having receiving portions and sleeve inserts coupled thereto.

[0070] FIG. 23 shows a block segment 750 having a plurality of receiving portions. For example, block segment 750 includes a first rim 762 and a second rim 764 adapted to receive a sleeve insert and which define a first position 761, a second position 763, and a third position 765 within the void 760. A sleeve insert 752 having through-hole 754 is placed into the first position 761. The sleeve insert 752 is shown as being shaped to fit within first position 761, although the sleeve insert 762 could also be shaped to fit within either or both of second position 763 and third position 765, according to certain embodiments.

[0071] Block segment 770 similarly includes a first rim 782 and a second rim 784; although these rim segments 782, 784 extend across the entire diameter of the void 780. The first rim 782 and the second rim 784 define a first position 781, a second position 783, and a third position 785. As shown in FIG. 24, a sleeve insert 772 is positioned within the second position 783. The sleeve insert 772 includes a through-hole 774 as well as tab portions 776. The tab portions may be provided on the sleeve insert 772 to control the depth at which the sleeve insert 772 is inserted into the second position 783 (or any other suitable position) of the void 780. Any suitable stop, such as tabs, flanges, or any other suitable appendage or combinations thereof, may be provided on sleeve inserts to control the depth or fit of the insert within a void, or to prevent rotation or misalignment of the insert relative to the position in which it should be placed.

[0072] In some embodiment, as discussed above in connection with receiving portions for cutting inserts, the receiving portions of an orthopedic block may be adjustable or removable. For example, FIG. 25 shows an orthopedic block segment 790 having a first removable rim 794 and a second removable rim 796 within the void 798. Each of the removable rims 794, 796 includes a mateable member 795, 797 that is disposed into a side of the void 798. The rims 794, 796 may be removed, repositioned, or otherwise adjusted to create one or more insert positions. For example, as shown in FIG. 25, the two removable rims 794, 796 define three insert positions within the void 798: first position 791, second position 792, and third position 793. If rim 794 is removed, the remaining rim 796 would define two insert positions. In this way, an orthopedic block has a modular number of positions that can be created by adding or removing the rims 794, 796. Furthermore, the size of the insert positions can be adjusted based on removing or inserting the removable rims 794, 796. For example, if rim 794 is removed, the insert position created (i.e., the combination of first position 791 and second position 792) would be relatively larger than the remaining third position 793. Although two removable rims 794, 796 are shown in FIG. 23, it will be understood that any suitable number of removable rims may be provided.

[0073] FIG. 26 shows a front elevation view of a multi-piece orthopedic block. In some embodiments, orthopedic blocks may be formed from two or more mating parts. Where two mating parts are used, the mating parts may have a mating interface at the cutting slot. For example, as shown in FIG. 26, multi-part orthopedic block 800 includes a first separable base portion 804 and a second separable base portion 805 joined together about interface region 811 on the medial and lateral ends of the orthopedic block to define a void 810 that can receive a cutting insert.

[0074] The surgeon first positions one of the cutting block parts, such as first separable base portion 804 or second separable base portion 805 on the patient's bone 830. The surgeon can then verify that the separable portion of the orthopedic block 800 is fitting well before pinning the orthopedic block on the bone and nailing down to the bone. After one of the mating parts of the cutting block is pinned down to the bone, the surgeon may cut against the mating interface for a non-captured cutting surface; or may attach the second of the two mating parts for resection using a captured slot. Other cuts may be made, for example, chamfer cuts, anterior cuts, and posterior cuts by the same patient-matched femoral cutting block by forming the block into modular sections which can be added or removed, or both. [0075] FIG. 27 shows a front exploded view of the multi-piece orthopedic block of FIG. 26. The first separable base portion 804 has been attached to a patient's femur 830. After attaching the first base portion 804 the surgeon may then position and couple the second base portion 805 to the first base portion 804 about interface region 811 in the direction shown by the arrow.

[0076] FIG. 28 shows a front elevation view of an orthopedic block 900 coupled to a patient's femur 932 in which a distal cut has already been made. The orthopedic block 900 can make anterior, posterior, or chamfer cuts, or any combinations thereof. Voids may be provided on the distal end of the orthopedic block 900 for receiving cutting inserts, sleeve inserts, or any other suitable inserts or combinations thereof. For example, as shown in FIG. 28, orthopedic block 900 includes sleeve inserts 902 and 904 positioned for receiving pins 906 via through-holes 903 and 905 to secure the orthopedic block 900 to the resected distal portion 931 of the patient's femur 932. Other voids (not shown) may be located on the distal end of the orthopedic block for receiving cutting inserts for making the anterior, posterior, and chamfer cuts to the patient's femur 932. Accordingly, although the above discussion has focused on orthopedic cutting blocks configured to make distal cuts, the concepts described herein apply equally to other types of cutting blocks, as well as various guide blocks, and any other suitable standard or patient-matched orthopedic blocks.

[0077] In some embodiments, instead of or in addition to inserts for reducing wear such as cutting inserts and sleeve inserts, hatch patterns may be built into one or more of the cutting guide surfaces such as the inner surface of a void. As another example, hatch patterns may be placed on one or more of the cutting slots' planar surfaces. Hatch patterns reduce surface area and serve to lower friction against the cutting blade. Some contemplated patterns are disclosed in U.S. Patent No. 6,645,251 , owned by Smith & Nephew, Inc., which is hereby incorporated by reference herein in its entirety. Bumps and protuberances may be used in lieu of hatch patterns to accomplish the same low wear properties. Such geometries and configurations may be provided by storing the patterns into a CAD file and then printing three-dimensional print outs using stereo lithography or selective laser sintering processes.

[0078] The orthopedic blocks of the present disclosure, such as cutting blocks and other guide blocks, may be formed of any suitable material including various polymers, metals, ceramics, or any other suitable materials or combinations thereof, including alloys. The orthopedic blocks are preferably patient-matched blocks formed of polymers such as nylon, polyetheretherketone (PEEK), polyphenylsulfone (PPSU), phenylsulfone (PSU), polyfulfone, each of which can be provided with or without reinforcement, to facilitate ease of fabrication of the patient-matched blocks. It will be understood that, unless explicitly stated otherwise, the foregoing discussion references orthopedic blocks formed of any of the above materials.

[0079] The inserts of the present disclosure, such as cutting inserts having cutting slots and sleeve inserts having through-holes for pin placement, may be formed of any suitable material including various metals, ceramics, gemstones such as ruby, or any other suitable material or combinations thereof including alloys. The inserts are preferably formed of metals or alloys to withstand the frictional engagement with cutting instruments during various surgical procedures. It will be understood that, unless explicitly stated otherwise, the foregoing discussion references inserts formed of any of these materials.

[0080] The foregoing is merely illustrative of the principles of the disclosure, and the systems, devices, and methods can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation. It is to be understood that the systems, devices, and methods disclosed herein, while shown for use in knee systems, may be applied to systems, devices, and methods to be used in other surgical procedures including, but not limited to, spine arthroplasty, cranio-maxillofacial surgical procedures, hip arthroplasty, shoulder arthroplasty, as well as foot, ankle, hand, and extremities procedures.

[0081] Variations and modifications will occur to those of skill in the art after reviewing this disclosure. The disclosed features may be implemented, in any combination and subcombination (including multiple dependent combinations and subcombinations), with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated in other systems.

Moreover, certain features may be omitted or not implemented.

[0082] Examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the scope of the information disclosed herein. All references cited herein are incorporated by reference in their entirety and made part of this application.

Claims

What is Claimed is:

1. An orthopedic cutting block comprising:

a void having a plurality of receiving portions, each receiving portion configured to receive a cutting insert.

2. The orthopedic cutting block of claim 1, wherein the plurality of receiving portions are adjustable.

3. The orthopedic cutting block of claim 1, wherein the plurality of receiving portions are removably positionable within the void.

4. The orthopedic cutting block of any of claims 1-3, further comprising a contact surface having at least one patient-matched contour structured to mate with an opposing feature of a patient's anatomy.

5. The orthopedic cutting block of any of claims 1-3, wherein each of the plurality of receiving portions is positioned in a different location relative to the void.

6. The orthopedic cutting block of any of claims 1-3, wherein the position of at least one receiving portion is predetermined according to patient-matched data.

7. The orthopedic cutting block of any of claims 1-3, further comprising a transparent window.

8. The orthopedic cutting block of any of claims 1-3, further comprising:

a cutting insert comprising:

a cutting slot having a cutting alignment; and

an outer surface removably coupled with one of the plurality of receiving portions.

9. The orthopedic cutting block of claim 8, wherein the orthopedic cutting block and the cutting insert are formed of different materials.

10. The orthopedic cutting block of claim 8, wherein the outer surface is configured to removably couple with one or more of the plurality of receiving portions.

11. The orthopedic cutting block of claim 8, wherein the cutting alignment is offset from the center of the void or directed at an angle with respect to the void.

12. The orthopedic cutting block of claim 8, wherein the cutting insert serves as a bearing surface.

13. The orthopedic cutting block of claim 8, wherein the outer surface of the cutting insert is correspondingly shaped with an inner surface of the void.

14. The orthopedic cutting block of claim 8, wherein the outer surface of the cutting insert is at least one of splined or keyed to a complimentary key on the orthopedic cutting block.

15. The orthopedic cutting block of claim 8, wherein the outer surface of the cutting insert is tapered.

16. The orthopedic cutting block of claim 8, wherein the cutting insert further comprises a fluid channel.

17. The orthopedic cutting block of claim 1, further comprising an attachment portion for removably attaching a drop rod.

18. A method for selecting a cutting block insert, the method comprising:

sequentially placing at least two inserts in a cutting block, each insert comprising a cutting slot having a respective predetermined cutting angle;

evaluating an acceptance criteria of each insert relative to patient-specific data; determining a preferred cutting angle based on the evaluation of the acceptance criteria; and

selecting an insert corresponding to the determined cutting angle.

19. The method of claim 18, wherein the patient-specific data comprises data indicative of one or more specific features of a patient's anatomy.

20. The method of claim 18, further comprising:

attaching a drop rod to a connecting portion of the selected insert; and visually and tactilely confirming an alignment position of the cutting block using the drop rod.

21. The method of claim 20, further comprising extending the drop rod from a first position to an extended position.

22. The method of claim 20, wherein visually confirming an alignment position further comprises viewing the alignment position through a transparent window set in the cutting block.

23. The method of claim 18, further comprising:

determining a preferred cutting depth based on the evaluation of the acceptance criteria; and

selecting an insert corresponding to the determined cutting depth and the determined cutting angle.

24. A kit comprising:

a plurality of orthopedic block inserts, each comprising:

an outer surface that removably couples with a void in an orthopedic block; and

a cutting slot configured to provide a cutting alignment that is offset from the center of the void or directed at an angle with respect to the void;

wherein each respective one of the plurality of orthopedic block inserts has a respective cutting alignment; and

at least one orthopedic block insert comprising a cutting slot configured to provide a cutting alignment in the center of the void.