Assembly and system including a tibial cut guide

Systems and apparatuses including a system that can be used in a knee replacement procedure are disclosed. According to one example, the system can include a tibial cut guide and an alignment guide. The tibial cut guide can have a first guide portion coupled to and adjustable relative to a second guide portion. The first guide portion can be configured to define a sagittal cut slot and the second guide portion can be configured to define a proximal cut slot. The alignment guide can be configured for extramedullary mounting to the patient and can be configured to couple with the second guide portion of the tibial cut guide. The alignment guide can have a first mechanism and a second mechanism of differing construction. The first mechanism and the second mechanism can both be configured to be actuated to facilitate extension and retraction of the alignment guide to position the tibial cut guide in a desired proximal-distal location relative a tibia of a patient when the tibial cut guide and the alignment guide are assembled together.

FIELD

The present subject matter relates to orthopedic procedures and, more particularly, to an assemblies and systems that can aid in bone resection for knee arthroplasties.

BACKGROUND

Orthopedic procedures and prostheses are commonly utilized to repair and/or replace damaged bone and tissue in the human body. For example, a knee arthroplasty can be used to restore natural knee function by repairing damaged or diseased articular surfaces of the femur and/or tibia. An incision is made into the knee joint to expose the bones comprising the joint. Cut guides are used to guide the removal of the articular surfaces that are to be replaced. Prostheses are used to replicate the articular surfaces. Knee prostheses can include a femoral component implanted on the distal end of the femur, which articulates with a tibial component implanted on the proximal end of a tibia to replicate the function of a healthy natural knee. Various types of arthroplasties are known including a total knee arthroplasty, where all of the articulating compartments of the joint are repaired with prosthetic components.

OVERVIEW

The present inventors recognize the need for an extramedullary alignment guide that can be used to quickly and accurately position (with regard to proximal-distal location, varus-valgus location, sagittal cut angle and medial-lateral location, and/or posterior slope angle) a tibial cut guide for removal of the articular surfaces of the tibia. The present inventors also recognize that the alignment guide can be provided a feature to make small adjustments to the proximal-distal location of the tibial cut guide once the alignment guide has already been fixated to the tibia can further reduce procedure time and improve accuracy. The inventors further recognize that the tibial cut guide can have a separate second portion defining a sagittal cut slot. This second portion can be adjustable relative to a remainder of the tibial cut guide (and indeed the alignment guide) to adjust a location and rotation angle of the sagittal cut. The tibial cut guide with the adjustable portion can allow for adjustment of the location and rotation angle of the sagittal cut after determining a desired proximal-distal location, varus-valgus location, and/or posterior slope angle for the tibial cut guide. This can allow for quicker and simpler adjust of the tibia cut guide to a desired position to perform resection. Further, the inventors recognize the need to adjust a proximal-distal position of the tibial cut guide in a rapid manner. Thus, one or more connections between portions of the alignment guide can be “quick-connect” or “quick-release” in nature to facilitate quick and accurate assembly, disassembly, positioning, and repositioning of the alignment guide and tibial cut guide.

To further illustrate the apparatuses and systems disclosed herein, the following non-limiting examples are provided:

Example 1 is a system for a knee replacement surgery that can include a tibial cut guide that can have a first guide portion coupled to and adjustable relative to a second guide portion and an alignment guide. The first guide portion can be configured to define a sagittal cut slot and the second guide portion can be configured to define a proximal cut slot. The alignment guide can be configured for extramedullary mounting to the patient and can be configured to couple with the second guide portion of the tibial cut guide. The alignment guide can have a first mechanism and a second mechanism of differing construction. The first mechanism and the second mechanism can both configured be actuated to facilitate extension and retraction of the alignment guide to position the tibial cut guide in a desired proximal-distal location relative a tibia of a patient when the tibial cut guide and the alignment guide are assembled together.

In Example 2, the subject matter of Example 1 can optionally include the alignment guide has a proximal assembly and a distal assembly. The distal assembly can include a rod having one or more engagement features along at least a portion thereof. The proximal assembly can be configured to be moveable relative to the distal assembly and can include a slot configured to receive at least a part of the rod therein. The proximal assembly can have an arm extending proximally, the arm can be configured to receive a fastener therein to couple the alignment guide to the tibia of the patient.

In Example 3, the subject matter of Example 2 can optionally include the distal assembly can be configured to couple with the first mechanism which can comprise a button that is configured to be depressible to facilitate adjustment of the proximal assembly relative to the distal assembly. The button can be configured to engage the one or more engagement features of the distal assembly.

In Example 4, the subject matter of any one or more of Examples 2-3 can optionally include wherein the proximal assembly can have a first body and a second body, and the first body can be moveable relative to the second body by the second mechanism.

In Example 5, the subject matter of Example 4 can optionally include the second mechanism can comprise a thumb screw configured to threadably engage the first body and be received within a recess of the second body.

In Example 6, the subject matter of Example 5 can optionally include wherein the thumb screw can be configured to retain one or more ball plunger assemblies and the second body can be configured with one or more grooves that can be configured to interact with the one or more ball plunger assemblies to act as indicia of a degree of movement of the second mechanism and an amount of proximal-distal travel of the first body relative to the second body.

In Example 7, the subject matter of any one or more of Examples 2-6 can optionally include both the first body and the second body can have indicia that when used together can be indicative of an amount of proximal-distal travel of the first body relative to the second body.

In Example 8, the subject matter of any one or more of Examples 1-7 can optionally include the first guide portion of the tibial cut guide can be configured to be adjustable both with respect to a medial-lateral position and a rotational position relative to the second guide portion.

In Example 9, the subject matter of any one or more of Examples 1-8 can optionally include the second guide portion can define a recess relative to the proximal cut slot. The recess can be configured to receive the first guide portion therein. The recess can at least partially be defined by anterior-posterior spaced projections configured to receive a pin therein. A leg of the first guide portion can be configured to insert between the anterior-posterior spaced projections and beneath the pin.

In Example 10, the subject matter of any one or more of Examples 1-9 can optionally include the sagittal cut slot communicates with an aperture. The aperture can be configured to receive a fastener therein to fix the first guide portion relative to the tibia and the second guide portion.

In Example 11, the subject matter of any one or more of Examples 1-10 can optionally include the proximal cut slot can be offset from a mount of the second guide portion in at least one of a medial or lateral direction and the proximal cut slot can be configured to define a medial-lateral cut length such that the proximal cut is to a single compartment of a knee.

Example 12 is an apparatus for guiding a tibial bone cut during knee replacement surgery, the apparatus can include a mount configured to couple with an alignment guide. A proximal guide portion can be connected to the mount and can be configured to define a proximal cut slot. The proximal cut slot can be offset from the mount in at least one of a medial or lateral direction and the proximal cut slot can be configured to define a medial-lateral cut length such that the proximal cut is to a single compartment of a knee. A sagittal guide portion can be coupled to and adjustable relative to the proximal guide portion. The sagittal guide portion can be configured to define a sagittal cut slot.

In Example 13, the subject matter of Example 12 can optionally include the sagittal guide portion can be configured to be adjustable both with respect to a medial-lateral position and a rotational position relative to the proximal guide portion.

In Example 14, the subject matter of any one or more of Examples 12-13 can optionally include the proximal guide portion can define a recess relative to the proximal cut slot. The recess can be configured to receive the sagittal guide portion therein. The recess can at least partially be defined by anterior-posterior spaced projections configured to receive a pin therein. A leg of the sagittal guide portion can be configured to insert between the anterior-posterior spaced projections and beneath the pin.

In Example 15, the subject matter of any one or more of Examples 1-14 can optionally include the sagittal cut slot can communicate with an aperture. The aperture can be configured to receive a fastener therein to fix the first guide portion relative to the tibia.

Example 16 is an alignment guide configured for extramedullary mounting to a patient for a knee replacement surgery, the alignment guide can include a first portion, a second portion, a first mechanism, a second mechanism, and a third portion. The first portion can have a rod with one or more engagement features along at least a portion thereof. The second portion can be moveable relative to the first portion and can have a slot configured to receive at least a part of the rod therein. The second portion can configured to receive at least a part of the first mechanism and the second mechanism. The first mechanism can be configured to be actuated facilitate proximal-distal adjustment of the second portion relative to the first portion. The third portion can at least partially received by the second portion and can be moveable relative thereto. The third portion can be configured to couple with a tibial cut guide. The second mechanism can be configured to be actuated to facilitate proximal-distal adjustment of the third portion relative to the second portion.

In Example 17, the subject matter of Example 16 can optionally include the first adjustment member and the second mechanism can have a differing construction but are both configured to allow the alignment guide to be extended and retracted to position the tibial cut guide in a desired proximal-distal location relative a tibia of a patient.

In Example 18, the subject matter of any one or more of Examples 16-17 can optionally include the second portion can have an arm configured to receive a fastener therein to couple the alignment guide to the tibia of the patient.

In Example 19, the subject matter of any one or more of Examples 16-18 can optionally include the second mechanism comprises a thumb screw that can be configured to threadably engage the third portion and be received within a recess of the second portion.

In Example 20, the subject matter of any one or more of Examples 17-19 can optionally include the thumb screw can be configured to retain one or more ball plunger assemblies and the second portion can be configured with one or more grooves that interact with the one or more ball plunger assemblies to act as indicia of a degree of movement of the second mechanism and an amount of proximal-distal travel of the third portion relative to the second portion.

In Example 21, the subject matter of any one or more of Examples 16-20 can optionally include both the third portion and the second portion can have indicia that when used together can be indicative of an amount of proximal-distal travel of the third portion relative to the second portion.

Example 22 is a method of performing a tibial knee resection that can include any one or combination of the following steps: mounting a tibial cut guide to an alignment mechanism, the tibial cut guide configured to facilitate both a proximal cut and a sagittal cut to a tibia; adjusting a proximal-distal location and varus-valgus location for a first slot that is used to define the proximal cut; fixating a first portion the alignment guide to the tibia of the patient; after fixating the first portion of the alignment guide to the tibia, adjusting a proximal-distal height of the cut guide by extending or retracting a second portion of the alignment guide relative to the first portion of the alignment guide; after adjusting the proximal-distal height of the cut guide, adjusting at least one of a medial-lateral location and a rotational angle of a second slot that is used to define the sagittal cut by moving a first guide portion of the tibial cut guide relative to a second guide portion with reference to one or more anatomical landmarks of the knee; and resecting the tibia by performing both the proximal cut and the sagittal cut utilizing the tibial cut guide.

In Example 23, the subject matter of Example 22 can optionally include fixating the first guide portion to the tibia prior to resecting the tibia.

In Example 24, the subject matter of any one or more of Examples 22-23 can optionally include the anatomical landmarks can include one or more of the intercondylar eminence of the tibia, a connection position of an ACL with the tibia, a medial third of a tubercle at insertion of a PCL, and an intercondylar geometry of a femur.

In Example 25, the apparatuses, systems and methods of any one or any combination of Examples 1 to 24 can optionally be configured such that all elements or options recited are available to use or select from.

These and other examples and features of the present apparatuses and systems will be set forth in part in the following Detailed Description. This Overview is intended to provide non-limiting examples of the present subject matter—it is not intended to provide an exclusive or exhaustive explanation. The Detailed Description below is included to provide further information about the present apparatuses and methods.

DETAILED DESCRIPTION

The present application relates to devices and systems for knee replacement procedures. For example, the present application discloses a tibial alignment guide that can position a tibial cut guide for removal of the articular surfaces of the tibia.

FIG. 1illustrates various axes of the lower limb in the frontal plane. Axes can be defined for each segment of the lower limb. For example, a femur10has an anatomic axis32coinciding generally with its intramedullary canal. It also has a mechanical axis34, or load axis, running from the center of the femoral head to the center of the knee. The angle36between these two axes32,34in the frontal plane varies within the patient population but is on the order of 4-9°. The two axes32,34are approximately superimposed in the sagittal plane. Likewise, a tibia12has a mechanical axis38coinciding generally with its intramedullary canal. The mechanical axis38of the tibia12runs from the center of the knee to the center of the ankle. The transverse axis, or joint line39, about which the knee flexes, is parallel to a line through the medial and lateral femoral condyles and parallel to the tibial plateau. Typically, the distal femur and proximal tibia are resected to be parallel to the joint line39, and thus perpendicular to the mechanical axes34,38as indicated at40and42. The intersection of the femoral and tibial mechanical axes34,38may subtend a small angle relative to one another. However, the angle can be small such that the axes34,38are approximately collinear and may be treated as collinear for most purposes.

A distal femoral cut can be made perpendicular to the femoral axes32,34in the sagittal plane. A proximal tibial resection is typically cut to match the natural posterior slope of the proximal tibia in the sagittal plane, relative to the mechanical axes34,38. The amount of posterior to anterior slope (also referred to herein as posterior slope angle) relative perpendicular to the mechanical axes34,38varies in the patient population but is on the order of 2° to 7°. The distance between the distal femoral cut and proximal tibial cut along the mechanical axes34,38is the extension gap. Other cuts may be made depending on the components that are to be implanted and the type of procedure performed.

As used herein, “proximal” refers to a direction generally toward the torso of a patient, and “distal” refers to the opposite direction of proximal, i.e., away from the torso of a patient. “Anterior” refers to a direction generally facing away from the patient, i.e. toward the surgeon performing the surgery, and “posterior” refers to the opposite direction of anterior, i.e., toward the front (anterior) of a patient or knee. In the context of the tibial alignment guide and tibial cut guide such as those disclosed herein, such directions correspond to the orientation of these when in use (i.e. when mounted to or adjacent the patient in an operable position to assist in making desired resections), such that a proximal assembly of the assembly is that portion which will ordinarily be closest to the torso of the patient, the anterior portion closest to the surgeon, the posterior portion generally closest to the anterior portion of the patient's knee, etc.

FIG. 2depicts six aspects of component positioning relative to a coordinate system in which the x-axis70(media-lateral axis) corresponds approximately to the joint line39, the z-axis72(proximal-distal axis) corresponds approximately to the mechanical axes34and38, and the y-axis74(anterior-posterior axis) is normal to the other two. Position along each of these axes is depicted by arrows. Position along the x, y, and z axes determines the medial-lateral (dx)76, anterior-posterior (dy)78, and proximal-distal (dz)80positioning of components respectively. Rotation about each of these axes is also depicted by arrows. Rotation about the z-axis (rz)82corresponds anatomically to external rotation of the femoral component, rotation about the x-axis (rx)84corresponds to extension plane rotation, and rotation about the y-axis (ry)86corresponds to varus/valgus rotation.

FIG. 3shows a system100according to one example of the present disclosure. When assembled the system100can comprise a tibial alignment guide102configured for extramedullary mounting to a patient. The system100can include an ankle clamp104, a distal assembly106, a proximal assembly108, a first mechanism110and a second mechanism112. The proximal assembly108includes a first body114and a second body116.

As shown the ankle clamp104can be configured to connect to the distal assembly106. The distal assembly106can be adjustable anterior-posterior relative to the ankle clamp104. The distal assembly106can have a portion extending generally proximal-distal when assembled. The proximal assembly108can be configured to be mounted on and moveable relative distal assembly106. For example, the proximal assembly108can receive the portion of the distal assembly106and can be adjustable generally proximal-distal relative to the distal assembly106via actuation of the first and/or second mechanisms110,112as will be discussed subsequently. Such adjustment of the proximal assembly108can allow the tibial alignment guide102to be extended and retracted to position a tibial cut guide in a desired proximal-distal location relative a tibia of a patient when the tibial cut guide and the alignment guide102are assembled together as will be further discussed subsequently.

The ankle clamp104can be configured with spring arms118adapted to clamp around an ankle of the patient such as proximal to the malleoli. The ankle clamp104can include a rod120that can have one or more engagement features (e.g., threads, slots, detents, teeth, etc.) along at least a portion thereof. The distal assembly106can be configured to receive the rod120therein. The distal assembly106can have a third mechanism122that can receive the rod120therein. The third mechanism122can be configured as a quick connect to couple with the one or more engagement features to fixedly connect the distal assembly106to the ankle clamp104. The third mechanism122can be configured to be actuated by the user to disengage the third mechanism122from the engagement feature(s) to allow for adjustment of the position of the distal assembly106relative to the ankle clamp104. Such adjustment can be facilitated by depressing and holding a button or similar feature of the third mechanism122, for example.

As shown in the example ofFIG. 3, the distal assembly106can include a rod124configured to extend generally proximal-distal when assembled with the ankle clamp104. The rod124can have one or more engagement features126(e.g., threads, slots, detents, teeth, etc.) along at least a portion thereof. The proximal assembly108can include a slot128(FIG. 5B) configured to receive at least a part of the rod124therein.

As shown inFIGS. 3 and 5A, the first mechanism110can be carried by the proximal assembly108at a distal portion thereof, for example. The first mechanism110that can receive the rod124(FIG. 3) therein. The first mechanism110can be configured to couple with the one or more engagement features126(FIG. 3) to fixedly connect the proximal assembly108to the distal assembly106. The first mechanism110can be configured to be actuated by the user to disengage the first mechanism110from the one or more engagement features126(FIG. 3) to allow for adjustment of the position of the proximal assembly108generally proximal-distal relative to the distal assembly106. Such adjustment can be facilitated by depressing and holding a button130or similar feature of the first mechanism110, for example.

In the example ofFIGS. 3 and 5A, the proximal assembly108can be comprised of the first body114and the second body116. The proximal assembly108(in particular the second body116) can also include an arm131extending proximally. The arm131can be configured to receive a fastener (not shown) or other component therein to couple the tibial alignment guide102to the tibia of the patient. The second body116can carry the first mechanism110. The second mechanism112can be received within a recess132(FIG. 5A) of the second body116proximal of the first mechanism110. The second mechanism112can be carried on the first body114, and indeed can be threadably engaged thereto with inter-engaging threads as will be discussed subsequently.

The first body114can be moveable relative to the second body116by the second mechanism112. Such movement of the first body114relative to the second body116can facilitate extension and retraction of the tibial alignment guide102to position the tibial cut guide in a desired proximal-distal location relative a tibia of a patient when the tibial cut guide and the alignment guide102are assembled together.FIGS. 3 and 5Ashow an example where the first mechanism110and the second mechanism112can be of differing construction (i.e. have different structure and operate according to different principles when actuated).

As shown inFIG. 4, the first mechanism110and the second mechanism112can both be configured to be actuated to facilitate generally proximal-distal movement of tibial alignment guide102. In particular, the first mechanism110and the second mechanism112can both be configured to be actuated to facilitate extension and retraction of the tibial alignment guide102to position the tibial cut guide134in a desired proximal-distal location relative a tibia136of a patient when the tibial cut guide134and the tibial alignment guide102are assembled together.

As shown inFIGS. 5B and 6A, the proximal assembly108can include the slot128configured to receive at least a part of the rod124(FIG. 3) of the distal assembly106(FIG. 3) therein. The first mechanism110can be configured to engage with the one or more engagement features126(e.g., threads, slots, detents, teeth, etc.) along at least a portion of the rod124(FIG. 3). This engagement can create a fixed connection between the proximal assembly108and the distal assembly106until the first mechanism110is disengaged by actuation by the user.

As shown inFIGS. 6A and 6B, the first mechanism110can comprise the button130, a spring138and a housing140. The housing140can define an opening142to the slot128.

The housing140can be configured to receive the rod124(FIG. 3) therethrough via the opening142defined by the housing140. The rod124(FIG. 3) can be T-shaped to match the slot128(FIG. 5B) and opening142according to one example. The housing140can further include an open end that is configured to receive a portion of the button130therein. The spring138(e.g., a conical compression spring) can be positioned between an end portion144(FIG. 6B) of the button130and an interior surface of the housing140. As shown inFIG. 6B, the button130can define an interior passage146proximal of and communicating with the opening142. The interior passage146can be provided with threading148configured to engage with the one or more engagement features126of the rod124(FIG. 3).

The button130can be configured to be depressible to facilitate adjustment of the proximal assembly108relative to the distal assembly106. As previously discussed, the button130can be configured to engage the one or more engagement features126(FIG. 3) of the distal assembly106(FIG. 3). The configuration of the first mechanism110can facilitate fast assembly and adjustment of the tibial cut guide to a desired position. Upon release of the button130, the spring138can push the inner threading148of the interior surface of the interior passage146into engaging contact with the one or more engagement features126of the rod124(FIG. 3) to lock the position of the posterior assembly108(and in particular the second body116) relative to the distal assembly106(FIG. 3).

FIG. 7shows an enlargement of a portion of the proximal assembly108and the second mechanism112. As shown inFIG. 7, the second mechanism112can comprise a thumb screw150configured to threadably engage (with threading151shown inFIGS. 7A and 7B) the first body114and be received within the recess132of the second body116.

As shown inFIGS. 7A to 7C, the thumb screw150can be configured to retain one or more ball plunger assemblies152therein such that only a ball portion154of the one or more ball plunger assemblies152can protrude from a distal surface156of the thumb screw150.

InFIG. 7D, the thumb screw is removed to illustrate the positioning of the one or more ball plunger assemblies152within the recess132of the second body116about the first body114. As shown in the example ofFIG. 7D, the second body116can configured with one or more grooves158that are configured to interact with the one or more ball plunger assemblies152(in particular the ball portion154) to act as indicia of a degree of movement of the second mechanism112and an amount of proximal-distal travel of the first body114relative to the second body116. For example, the one or more grooves158and the one or more ball plunger assemblies152can interact to make a clicking noise to indicate 90 degrees of rotational movement of the second mechanism112, and further, the clicking noise can indicate 1 mm of proximal-distal travel of the first body114relative to the second body116.

FIG. 8Ashows a proximal portion160of the proximal assembly108. As shown inFIG. 8A, the first body114can include a coupling mechanism162. The second body116can include the arm131extending proximally and having the through hole133configured to receive a fastener. As shown in the example ofFIG. 8A, both the first body114and the second body116can have indicia163A and163B, respectively. When used together, the indicia163A and163B are indicative of an amount of proximal-distal travel of the first body114relative to the second body116. According to one example, the indicia163A can comprise a reference line while the indicia163B can comprise a series of 1.0 mm separated lines and additionally a reference line164indicating a neutral position. As shown inFIG. 8A, the indicia163B can indicate ±5.0 mm relative to the neutral position. The indicia163A and163B can be used with adjustment of the first body114relative to the second body116using the second mechanism112(FIGS. 7A-7D) after pinning the second body116to the tibia via through hole133as previously discussed.

The coupling mechanism162is configured to engage with and be actuated to couple the tibial cut guide134(FIGS. 4 and 9 to 10D). The coupling mechanism162shown inFIG. 8Aincludes a slot166and pin168and is further illustrated and described with reference toFIGS. 8B and 8C. The slot166can allows for an amount of proximal-distal travel of the pin168as will be discussed subsequently. Coupling mechanisms that may be constructed and/or operate in a similar manner as the coupling mechanism162are described in United States Patent Application Pub. 2013/0204260, U.S. patent application Ser. No. 15/184,016, and U.S. Provisional Patent Application Ser. No. 62/254,474, the entire disclosures of which are incorporated herein by reference.

Turning toFIG. 8B, the coupling mechanism162can include a housing170, a body component172, a spring174, a lever176, a member178and first and second pins168,182. The body component172of the coupling mechanism162can include first and second slots184,186(only shown inFIG. 8C).

As illustrated inFIG. 8B, the housing170can comprise a hollow containment member having openings at both the proximal end and a distal side thereof. The body component172can reside therein, and can have a conic head portion188that extends therefrom on a proximal end. As will be discussed, the body component172can be moveable relative to the housing170in a constrained manner. The spring174can be positioned within the body component172(between the first pin168and an inferior surface of a head of the member178). The member178can be contacted on a superior surface of the head by the surfaces of lever176. The lever176can extend from the distal side opening of the housing170and a distal side opening of the body component172as shown inFIG. 8Ba. The second pin182can be can be received in an aperture or slot of the body component172. The first pin168can be received in the slot168of the housing170and can be received in the first slot184of the body component172.

In operation, the lever176can be actuated upward (pivoting about the first pin168) away from the position shown inFIGS. 8A to 8Cto unlock the coupling mechanism162to facilitate removal of and/or addition of the tibial cut guide, which is mounted to a conic head portion188. Movement of the lever176can allow the body component172to be translated upward relative to the housing170. The spring174may not be constrained until the first pin168contacts the proximal end of the slot166in the housing170. With movement of the body component172proximally, the conic head portion188has sufficient clearance relative to a proximal end portion of the housing170such that a mating female conic portion of the tibial cut guide can be mounted to the body component172and the housing170. When the lever176is pivoted back to the distal position illustrated inFIGS. 8A to 8C, a conic lock between the cut guide and the conical head portion188is maintained by the spring174such that the male conic portion188is in fully engaged contact and is seated with the female conic portion located on the tibial cut guide. The projection190extending proximally from the proximal end of the housing170can be configured to fit in a female counterpart slot or recess in the tibial cut guide. In this manner, the body component172and the housing170can constrain the proximal-distal and rotational movement of the tibial cut guide.

FIG. 9shows a system200including the tibial cut guide134and the tibial alignment guide102as previously discussed. The tibial cut guide134can include a mount202configured to couple with the male conic portion188of the tibial cut guide102as previously described.

The tibial cut guide134is further illustrated in reference toFIGS. 10A to 10D. The tibial cut guide134can include a first guide portion204and a second guide portion206.

The mount202can connect to and indeed can be formed as port of the second guide portion206. The first guide portion204can be coupled to and can be adjustable relative to the second guide portion206. The first guide portion204can configured to define a sagittal cut slot208. The second guide portion is configured to define a proximal cut slot210. The sagittal cut slot208and the proximal cut slot210are configured to limit travel and orient a sagittal resection and a proximal resection, respectively, when performed on the tibia. Such cuts can be performed using known cutting tools. According to the example ofFIGS. 10A to 10D, the tibial cut guide134can be configured for resection of a single compartment of the tibia. More particularly, the proximal cut slot210can be offset from the mount202of the second guide portion206in at least one of a medial or lateral direction. The proximal cut slot210can be configured to define a medial-lateral cut length such that the proximal cut is to a single compartment of a knee.

As shown by arrows inFIG. 10B, the first guide portion204can be configured to be adjustable both with respect to a medial-lateral position (as shown by arrow ML) and a rotational position (as shown by arrow A) relative to the second guide portion206. Changing the rotational position of the first guide portion204can change the angle of the sagittal cut slot208from the neutral position shown inFIGS. 10B and 10Csuch that the sagittal cut slot208can be angled (i.e. canted) to extend, a medial-lateral distance, a proximal-distal distance and an anterior-posterior distance. In the neutral position, the sagittal cut slot208can be oriented to extend substantially only the proximal-distal distance and anterior-posterior distance. The change in angle can be of varying degree as desired. The angle of the sagittal cut slot208can be changed ±1°, 3°, or 5° relative to the neutral position shown inFIGS. 10B and 10C, for example. Similar, the position of the sagittal cut slot208can be changed medial-lateral by ±1.0, 3.0, or 5.0 mm relative to the neutral position shown inFIGS. 10B and 10C.

FIGS. 10B and 10Cfurther show that the second guide portion206can define a recess212relative to the proximal cut slot210. The recess212can be configured to receive the first guide portion204therein. The recess212can be open along a portion of the medial-lateral length thereof, but can be at least partially defined by along such length by anterior-posterior spaced projections214A,214B configured to receive a pin216therein. The first guide portion204can be configured with a leg218that can be configured to insert between the anterior-posterior spaced projections214A,214B and beneath the pin216. The tibial cut guide200can be configured with some degree of freedom between the leg218, the anterior-posterior spaced projections214A,214B, and the pin216to allow for the adjustment of the rotational position and/or the medial-lateral position of the first guide portion204relative to the second guide portion206as previously described.

As shown inFIGS. 10A and 10C, the sagittal cut slot208can communicate with an aperture220. The aperture220can be configured to receive a fastener therein to fix the first guide portion204relative to the tibia and the second guide portion206. The fastener or other feature, when received in the aperture220, can act as a stop for a cutting tool making a sagittal resection of the tibia.

With reference to the FIGURES presented herein, a method for performing a tibial knee resection is also disclosed herein. The method can include mounting a tibial cut guide to an alignment mechanism. The tibial cut guide can be configured to facilitate both a proximal cut and a sagittal cut to a tibia. The method can adjust a proximal-distal location and varus-valgus location for a first slot that is used to define the proximal cut. A first portion of the alignment guide can be fixated to the tibia of the patient. Such step of fixation can occur after adjusting the proximal-distal location and varus-valgus location for the first slot as desired according to one example. After fixating the first portion of the alignment guide to the tibia, the method can adjust a proximal-distal height of the cut guide by extending or retracting a second portion of the alignment guide relative to the first portion of the alignment guide. Such extending and retracting can be in a generally proximal-distal direction according to one example. After adjusting the proximal-distal height of the cut guide, the method can adjust at least one of a medial-lateral location and a rotational angle of a second slot of the tibial cut guide that is used to define the sagittal cut by moving a first guide portion of the tibial cut guide relative to a second guide portion with reference to one or more anatomical landmarks of the knee. According to some examples, after adjusting the at least one of the medial-lateral location and the rotational angle of the second slot that can be used to define the sagittal cut, the method can fixate the first guide portion to the tibia prior to resecting the tibia. Resection of the tibia can be accomplished by performing both the proximal cut and the sagittal cut utilizing the tibial cut guide. The anatomical landmarks used with the method can include one or more of the intercondylar eminence of the tibia, a connection position of an ACL with the tibia, a medial third of a tubercle at insertion of a PCL, and an intercondylar geometry of a femur according to one example.

Additional Notes