Patent ID: 12226108

It is to be understood that the drawings are for purposes of illustrating the concepts of the disclosure and may not be drawn to scale. Furthermore, the drawings illustrate exemplary embodiments and do not represent limitations to the scope of the present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present disclosure, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus and method, as represented in the Figures, is not intended to limit the scope of the present disclosure, as claimed in this or any other application claiming priority to this application, but is merely representative of exemplary embodiments of the present disclosure.

Standard medical directions, planes of reference, and descriptive terminology are employed in this specification. For example, anterior means toward the front of the body. Posterior means toward the back of the body. Superior means toward the head. Inferior means toward the feet. Medial means toward the midline of the body. Lateral means away from the midline of the body. Axial means toward a central axis of the body. Abaxial means away from a central axis of the body. Ipsilateral means on the same side of the body. Contralateral means on the opposite side of the body. A sagittal plane divides a body into right and left portions. A midsagittal plane divides the body into bilaterally symmetric right and left halves. A coronal plane divides a body into anterior and posterior portions. A transverse plane divides a body into superior and inferior portions.

An anterior-posterior axis is an axis perpendicular to the coronal plane. A medial-lateral axis is an axis perpendicular to the median plane. A cephalad-caudal axis is an axis perpendicular to the transverse plane. These descriptive terms may be applied to an animate or inanimate body.

The phrases “connected to,” “coupled to” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be functionally coupled to each other even though they are not in direct contact with each other. The term “abutting” refers to items that are in direct physical contact with each other, although the items may not necessarily be attached together. The phrase “fluid communication” refers to two features that are connected such that a fluid within one feature is able to pass into the other feature.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The present disclosure discloses a gap gauge for facilitating an arthroplasty procedure on a first bone and a second bone of a patient. During an arthroplasty procedure, a surgeon may need to confirm that the gap between two bones of the joint is of a desired displacement and that the joint has a desired balance (e.g. balanced, varus condition, or valgus condition). Using separate instruments to get either the displacement or the balance status can complicate the procedure and may require more personnel to assist in the procedure. As one instrument is exchanged for another (e.g., an instrument that only measures displacement exchanged for an instrument that only measures balance status), parts of a joint can shift and thus alter a displacement already measured or alter a balance status read using an instrument that cannot provide both displacement measurements and a balance status, or balance measurement in a single instrument. Consequently, a need exists for an improved gap gauge. In particular, a need exists for gap gauge that can provide both a displacement measurement and a balance status (e.g., balance measurement) using a single instrument. Furthermore, the present disclosure provides for a gap gauge that enables a user to optionally disengage/disable a balance indicator or balance gauge168during use for that a user can use the same instrument to only measure displacement between two joint bones, if desired.

FIG.1Ais a perspective view depicting one exemplary embodiment of a gap gauge100for facilitating an arthroplasty procedure on a first bone and a second bone of a patient. As used herein, an “arthroplasty procedure” refers to a surgical procedure for restoring and/or improving function and/or operation of a joint of a patient. An arthroplasty procedure can be done for a toe joint, ankle joint, knee joint, hip joint, arm joint, elbow joint, finger joint, or the like. In the illustrated embodiment, the first bone can be a femur102and the second bone can be a tibia104. As used herein, a “gap gauge” refers to an apparatus, instrument, structure, device, component, system, assembly, hardware, software, firmware, circuit, module, or logic structured, organized, configured, programmed, designed, arranged, or engineered to measure an attribute, characteristic, state, or condition of another structure or object or set of structures or objects. In one embodiment, the gap gauge is structured, organized, configured, programmed, designed, arranged, or engineered to measure a displacement between two structures.

As part of an arthroplasty procedure, the gap gauge100can be inserted into an opening106, also referred to as a gap, between the first bone and the second bone. The gap gauge100can be used to determine how much displacement exists between the first bone and the second bone within the opening106. As used herein, an “opening” refers to a gap, a hole, an aperture, a void in a structure, or the like. In certain embodiments, an opening can refer to a structure configured specifically for receiving something and/or for allowing access. The amount of displacement can be referred to herein as measuring a gap, or space, between the first bone and second bone.

In addition, or alternatively, the gap gauge100can be used to determine a balance status of a joint108that is part of the arthroplasty procedure. The joint108can be a toe joint, ankle joint, knee joint, hip joint, arm joint, elbow joint, finger joint, or the like. In the illustrated embodiment, the joint108is a knee joint and the first bone is a femur102and the second bone is a tibia104. Gap gauge100can be used to determine both displacement within the opening106and a balance status using a single device. Alternatively, a user, such as a surgeon, can use the gap gauge100to determine displacement or a balance status using a single convenient device with the first bone and second bone in flexion, in extension, or at an angle between flexion and extension.

FIG.1Aillustrates a three-dimensional axis110. The three-dimensional axis110includes a cephalad-caudal axis112, a medial-lateral axis114, and an anterior-posterior axis116. The three-dimensional axis110is used to identify how a gap gauge100is positioned and/or oriented with respect to an anterior-posterior axis116of a patient who is in a reference anatomical position.

FIG.1Bis a perspective view of the gap gauge100ofFIG.1A.FIG.1Billustrates the gap gauge100without a first bone or second bone shown. The gap gauge100may generally include a first plate, a second plate, a separator, a separation indicator, and a balance indicator. In the illustrated embodiment, the first plate may be an inferior plate120and the second plate may be a superior plate118. The illustrated gap gauge100also includes a separator122, a separation indicator124, and a balance indicator126.

In one embodiment, the superior plate118is a plate. As used herein, a “plate” refers to a flat structure or a generally flat structure. In certain embodiments, a plate can be configured to support a load. In certain embodiments, a plate may comprise a generally planar structure. A plate can be a separate structure connected to, or integrated with, another structure. Alternatively, a plate can be connected to part of another structure. A plate can be two-dimensional or three-dimensional and can have a variety of geometric shapes and/or cross-sectional shapes, including, but not limited to a rectangle, a square, or other polygon, as well as a circle, an ellipse, an ovoid, or other circular or semi-circular shape. A plate can be made from a variety of materials including, metal, plastic, ceramic, wood, fiberglass, or the like. The inferior plate120can also be a plate.

The superior plate118can be positioned opposite the inferior plate120. The superior plate118can be positioned in contact with a first bone (e.g., a femur102). The inferior plate120can be positioned in contact with a second bone (e.g., a tibia104). The superior plate118and inferior plate120can be parallel to each other and cooperate to slide into an opening or gap.

In one embodiment, the superior plate118and inferior plate120have a structural integrity that permits them to be positioned, (e.g., inserted) between a femur102and a tibia104. When initially positioned between two bones, the superior plate118and inferior plate120may contact each other as illustrated inFIG.1A. Once positioned between two bones, a user may move the superior plate118relative to the inferior plate120which adjusts a displacement128between the superior plate118and the inferior plate120. When the superior plate118and inferior plate120contact each other, the displacement128may be zero. In one embodiment, the superior plate118and inferior plate120may be displaced from each other by a displacement128when the gap gauge100is initially manufactured/assembled.

As used herein, a “displacement” refers to a vector that measures how much a structure, member, object, component, or part has moved, changed position, from a starting position to an ending position, or measures the distance between two objects. Displacement can be measured using a variety of units of measure including imperial units, metric units, angular units and the like. In certain embodiments, the displacement is measured in millimeters. In one embodiment, the displacement128may range from zero to twenty-five or more millimeters.

A user may adjust the displacement128. A user may separate the superior plate118and the inferior plate120by manually pulling them apart and/or the user may use the separator122to separate the superior plate118and the inferior plate120. A user may bring the superior plate118and the inferior plate120together by manually positioning them and/or the user may use the separator122to bring the superior plate118and the inferior plate120together.

The separator122connects to the superior plate118and to the inferior plate120. The separator122can adjust the displacement128. In one embodiment, actuation of the separator122adjusts the displacement128. As used herein, a “separator” refers to an apparatus, instrument, structure, device, component, system, assembly, or module structured, organized, configured, programmed, designed, arranged, or engineered to separate a first structure from another structure. In one embodiment, the separator is structured, organized, configured, programmed, designed, arranged, or engineered to separate a first plate from a second plate and thereby create a distance between the first plate and the second plate. The separator122can actively adjust the displacement128and/or retain the superior plate118and inferior plate120in a certain state of separation, thereby maintaining a desired displacement128.

The separation indicator124indicates the displacement128between the superior plate118and the inferior plate120. The separation indicator124can be coupled to the separator122. As used herein, a “separation indicator” refers to an apparatus, device, component, system, assembly, hardware, software, firmware, circuit, module, or logic structured, organized, configured, programmed, designed, arranged, or engineered to indicate a displacement between two or more structures to a user. The separation indicator can include one or more of an audible signal, a tactile signal, a visual signal or indication, and the like. In one embodiment, a visual indicator for the separation indicator may comprise a number or set of numbers that represent a unit of measure for the displacement (or distance) between the two or more structures. Alternatively, or in addition, the separation indicator may comprise a mechanical device, an electromechanical device, an electronic device (analog or digital), and the like.

The balance indicator126indicates a balance status. As used herein, a “balance indicator” refers to an apparatus, device, component, system, assembly, mechanism, hardware, software, firmware, circuit, module, or logic structured, organized, configured, programmed, designed, arranged, or engineered to indicate a balance status to a user of a device or apparatus that includes the balance indicator. The balance indicator can include one or more of an audible signal, a tactile signal, a visual signal or indication, and the like. Alternatively, or in addition, the balance indicator may comprise a mechanical device, an electromechanical device, an electronic device (analog or digital), and the like. As used herein, a “balance status” refers to a condition, state, attribute, value, and/or characteristic, of one or more members, components, structures, and/or openings relative to a state of desired, correct, and/or equal proportions, configuration, alignment, and/or orientation between a reference set of one or more members, components, structures, and/or openings and the one or more members, components, structures, and/or openings being evaluated, measured, or examined. In certain embodiments, the balance status can be a binary condition, state, attribute, value, and/or characteristic. For example, a relationship between the one or more structures or openings and a reference set of one or more structures or openings may be either balanced or unbalanced (also referred to as imbalanced).

Alternatively, or in addition, a balance status can be a condition, state, attribute, value, and/or characteristic within a range of possible conditions, states, attributes, values, and/or characteristics. For example, in one embodiment, a balance status may be measured with respect to a scale or range of degrees between a positive maximum value and a negative minimum value where a balance status of zero on the range represents a balanced state and a non-zero value along the range represents an unbalanced state. In one embodiment, a range used to measure the balance status may extend from −5 degrees to +5 degrees.

In certain embodiments, a balance status can represent whether, or not, a superior resection of one bone of a joint is parallel to an inferior resection of another bone of the joint. In another embodiment, a balance status can represent a degree to which a superior resection of one bone of a joint is, or is not, parallel to an inferior resection of another bone of the joint. In another embodiment, a balance status can represent how two bones of a joint and space/opening between them relate to a medial collateral ligament and a lateral collateral ligament interact to each other to achieve a desired relationship with the joint.

In one embodiment, the balance indicator126indicates a balance status between the superior plate118and the inferior plate120. Alternatively, or in addition, the balance indicator126may indicate a balance status for a joint108and/or between a medial collateral ligament and a lateral collateral ligament of a joint108. Alternatively, or in addition, the balance indicator126may indicate a balance status between a first bone and a second bone. In the context of knee arthroplasty, the balance indicator126may indicate whether the arthroplasty procedure, if completed with implants on the measured bone surfaces, is likely to be varus, valgus, or balanced.

The balance indicator126can be connected to one, or the other, or both, of superior plate118and the inferior plate120. In one embodiment, the balance indicator126connects to the superior plate118. The balance indicator126is illustrated as a dashed region of the gap gauge100because one or more components or elements in the dashed region can serve as the balance indicator126in different embodiments. For example, in one embodiment, a user may observe a non-parallel position of the superior plate118, or part of the superior plate118, and such observation may serve as the balance indicator126.

FIGS.1C-1Iillustrate a top view (FIG.1C), bottom view (FIG.1D), side views (Figure E-G), rear view (FIG.1H), and front view (FIG.1I) of one embodiment of a gap gauge100.FIG.1Cillustrates an embodiment that includes a lock-out mechanism130, a pair of grips132, and a handle134. As used herein, a “handle” refers to a structure used to hold, control, or manipulate a device, apparatus, component, tool, or the like. A “handle” may be designed to be grasped and/or held in one or more hands of a user.

In certain embodiments, the lock-out mechanism130can be used by a user to disable, prevent, or turn off actuation of the balance indicator126to indicate a balance status. As used herein, a “lock-out mechanism” refers to an apparatus, instrument, structure, device, component, system, assembly, hardware, software, firmware, circuit, module, or logic structured, organized, configured, programmed, designed, arranged, or engineered to prevent, mitigate, or stop operation of a balance indicator of a gap gauge such that the balance indicator does not report a balance status when the gap gauge is actuated. In one embodiment, the lock-out mechanism can prevent rotation of a plate connected to the balance indicator of a gap gauge. The pair of grips132can be used by a user to position the superior plate118relative to the inferior plate120. For example, a user may grab the pair of grips132with one hand and hold the handle134with another hand and pull up on the grips132to separate the superior plate118and the inferior plate120.

FIG.1Dillustrates a bottom view of one embodiment of the gap gauge100. The view shows the inferior plate120, lock-out mechanism130, grips132, and handle134.

FIG.1Eillustrates a side view of one embodiment of the gap gauge100. The view shows the superior plate118, inferior plate120, separator122, a grip132, and a handle134. In addition, the illustrated embodiment includes a superior body136, an inferior body138, a shaft140, and a spring142. As used herein, a “body” refers to a main or central part of a structure. In one embodiment, a body may include a housing or frame or framework for a larger system, component, structure, or device. A body may include a modifier that identifies a particular function, location, orientation, operation, and/or a particular structure relating to the body. Examples of such modifiers applied to a body, include, but are not limited to, “inferior body,” “superior body,” “lateral body,” “medial body,” and the like. As used herein, a “spring” refers to an elastic structure that stores mechanical energy. Springs can be made of a variety of elastic material such as spring steel and can be cylindrical and/or helical in shape. Various types of springs can be used including coil springs, torsion springs, and the like. (Search “spring (device)” on Wikipedia.com Nov. 28, 2020. Modified. Accessed Jan. 6, 2020.)

The superior body136provides structural support and integrity for the gap gauge100and may house one or more parts of the gap gauge100. The inferior body138provides structural support and integrity for the gap gauge100and may house one or more parts of the gap gauge100. In one embodiment, the superior plate118extends from the superior body136and the inferior plate120extends from the inferior body138.

The shaft140may couple or connect the superior body136to the inferior body138. The shaft140may slidably couple with the superior body136to the inferior body138. The slidable coupling between the shaft140, the superior body136, and the inferior body138permits adjustment of the displacement128.

In one embodiment, the shaft140may fit within an opening in the superior body136and pass through the superior body136to engage the inferior body138. In certain embodiments, the shaft140can include threads on the outside of one end of the shaft140. The threads of the shaft140may engage threads of an opening in the inferior body138to connect the shaft140to the inferior body138. The shaft140may include a head144on one end opposite an end that includes the threads.

The opening in the superior body136can be sized to accept the shaft140and the spring142coiled around the outside of the shaft140. The spring142may contact the superior body136and the head144. The shaft140and spring142cooperated to retain the superior body136connected to the inferior body138. In one embodiment once assembled in the gap gauge100, the spring142may be biased against the head144and the superior body136. The spring142can bias the superior body136in opposition to movement of the superior plate118away from the inferior plate120.

In certain embodiments, the gap gauge100may include a post146. The post146may slidably engage the superior body136and be connected to the inferior body138. In one embodiment, the post146may be screwed into an opening in the superior body136. The post146may cooperate with the shaft140to maintain movement of the superior body136along a single axis.

FIG.1Fillustrates a side view of one embodiment of the gap gauge100. The side view shows the superior plate118, inferior plate120, separator122, a lock-out mechanism130, a grip132, a handle134, a superior body136, inferior body138, a shaft140, a spring142, and a post146.

FIG.1Gillustrates a side view of one embodiment of the gap gauge100. The side view shows the superior plate118, inferior plate120, separator122, a lock-out mechanism130, a grip132, a handle134, a superior body136, inferior body138, a shaft140, spring142, and a post146.

FIG.1Gillustrates the gap gauge100with the separator122actuate such that the superior plate118and inferior plate120are displaced from each other by a displacement128. In one embodiment, the displacement128is a measure between an external surface of the superior plate118and an external surface of the inferior plate120. Those of skill in the art will recognize that a displacement can also be a measure between an internal surface of the superior plate118and an internal surface of the inferior plate120indicated by displacement128′.

In the illustrated embodiment, the gap gauge100may include a superior plate118that includes a pivot plate148and a support plate150. The pivot plate148can be connected, or coupled, to the support plate150such that the pivot plate148can serve as a balance indicator126. In one embodiment, the pivot plate148can pivot about the anterior-posterior axis116relative to the support plate150. As used herein, a “support plate” refers to a plate structured, organized, configured, programmed, designed, arranged, or engineered to support a load.

FIG.1Hillustrates a rear view of one embodiment of the gap gauge100. The rear view shows the superior plate118, inferior plate120, separation indicator124, balance indicator126, grips132, handle134, shaft140, spring142, pivot plate148, and support plate150. In one embodiment, the inferior plate120can be a first plate and the superior plate118can be a second plate, or vice versa. Furthermore, in certain embodiments, the inferior plate120can be a second plate and the pivot plate148can be the first plate, or vice versa. In such embodiments, the gap gauge100may not include a support plate150.

FIG.1Hillustrates an embodiment of a gap gauge100that includes a driver152and a fastener154. The driver152serves to actuate the separator122. The driver152can include a circumference having curved slots that facilitate rotating the driver152. In one embodiment, the driver152serves to engage the separator122such that a displacement128is maintained. As used herein, a “driver” refers to a mechanical piece, component, or structure for imparting motion to another piece, component, or structure. (“driver.” Merriam-Webster.com. Merriam-Webster, 2021. Web. 6 Jan. 2021. Modified.) In certain embodiments, a driver can be a wheel configured or connected to other parts such that rotation or motion of the driver causes motion of other interconnected or intercoupled parts of a component, system, apparatus, or device.

The fastener154secures the driver152to the gap gauge100. In one embodiment, the fastener154is a bolt that screws into the inferior body138and permits the driver152to rotate freely about the bolt.

FIG.1Iillustrates a front view of one embodiment of the gap gauge100. The front view shows the superior plate118, inferior plate120, grips132, handle134, shaft140, spring142, pivot plate148, and support plate150. In one embodiment, the balance indicator connects to a second plate, such as superior plate118, and the balance indicator includes a hinge156that pivotally connects the superior plate118to the gap gauge100. In one embodiment, the hinge156connects to the support plate150.

As used herein, a “hinge” refers to an apparatus, instrument, structure, device, component, member, system, assembly, or module structured, organized, configured, designed, arranged, or engineered to connect two structures such that one structure can rotate about a fixed longitudinal axis of the hinge with respect to the other structure. In one embodiment, a hinge may be considered a mechanical bearing that restricts relative movement of the two structures to a desired kind of movement. In certain embodiments, various types of hinges can be used including a barrel hinge, a butt hinge, a butterfly hinge, a case hinge, a concealed hinge, a continuous/piano hinge, a flag hinge, an H hinge, an HL hinge, a pivot hinge, a self-closing hinge, a spring hinge, a living hinge, a coach hinge, a flush hinge, or the like.

A hinge can include a pin, one or more knuckles (also referred to as loops, joints, nodes, curls, etc.), and one or more leaves. As used herein, a “pin” refers to a cylindrical structure having a cross-sectional diameter small enough to fit within openings of one or more knuckles of a hinge. In certain embodiments, the pin can include a head on one end, the head can be larger than a diameter of the openings of the one or more knuckles such that the head prevents the pin from passing completely through the openings of the one or more knuckles. A pin can be made from a variety of material including metal, plastic, wood, or the like. A leaf is a structure that extends laterally from the one or more knuckles and can be integrated with or connected to a structure that is intended to pivot or rotate about the pin. In certain embodiments, a hinge can include two or more leaves. A leaf can be a planar structure.

A knuckle is a structure with an opening sized to receive the pin. A knuckle connects to at least one leaf. A knuckle can have a circular longitudinal cross-section and can be cylindrical. In certain embodiments, each leaf includes a knuckle that can be aligned along a longitudinal axis of the hinge. Once the one or more knuckles are aligned along the longitudinal axis of the hinge, the pin can be inserted into openings of the one or more knuckles to secure the leaf/leaves connected to each knuckle.

FIG.1Iincludes a front view of one embodiment of a balance indicator126. In such an embodiment, the superior plate118can include a pivot plate148coupled to the gap gauge100by the hinge156. In certain embodiments, the hinge156may serve both as a hinge and as a balance indicator126. For example, a user may view the hinge156during an arthroplasty procedure and detect that the pivot plate148(or the superior plate118) is oriented non-parallel to an inferior plate120. In this manner, a user can determine a balance status.

In one embodiment, the hinge156can include a pin158. The pin158can couple, or connect, to the pivot plate148. The pin158can connect the support plate150and the pivot plate148. In another embodiment, the hinge156may not connect to a support plate150. The pin158has a longitudinal axis160that is a pivot axis162for the pivot plate148. A force (e.g., a force in the direction of arrow164or arrow166) applied to the pivot plate148can rotate the pivot plate148about the pin158. As used herein, a “pivot axis” refers to an axis about which a structure pivots or rotates.

During an arthroplasty procedure, a user may align the longitudinal axis of the pin158, and hence the pivot axis of the pivot plate148, with an anterior-posterior axis116of a patient in order to determine a balance status. Alternatively, or in addition, during an arthroplasty procedure, a user may position the longitudinal axis of the pin158, and hence the pivot axis of the pivot plate148, parallel to an anterior-posterior axis116of a patient in order to determine, or measure, a varus condition, a balanced condition, or a valgus condition.

If the pivot plate148pivots about the pin158in the direction of arrow164, this may indicate a varus condition of a first bone relative to a second bone. If the pivot plate148pivots about the pin158in the direction of arrow166, this may indicate a valgus condition of a first bone relative to a second bone. If the pivot plate148does not pivot about the pin158, this may indicate a balanced condition of a first bone relative to a second bone.

FIGS.2and3are anterior views of a knee joint with the gap gauge100ofFIG.1Ainserted between two bones and show a balanced condition and a varus condition, respectively. A figure showing bones of a joint for a valgus condition is not specifically shown; however, those of skill in the art will appreciate that a valgus condition is simply an angle, or orientation, of the bones ofFIG.3such that the pivot plate148pivots in the direction of arrow166rather than arrow164.

As used herein, a “valgus condition” refers to a state of a bone or joint having an undesired outward angulation (angled laterally, away from the body's midline) of the distal segment of a bone or joint. For example, in a valgus condition of the knee, the distal part of the leg below the knee is deviated outward, in relation to the femur, resulting in a knock-kneed appearance. The opposite of varus is called valgus. A varus condition at the knee results in a bowlegged appearance with the distal part of the leg deviated inward, in relation to the femur. (Search “valgus deformity” on Wikipedia.com Oct. 20, 2020. Modified. Accessed Jan. 6, 2020.) A valgus condition can be experienced in a variety of joints, including but not limited to, ankle joints, elbow joints, foot joints, hand joints, hip joints, knee joints, toe joints, wrist joints, and the like. As used herein, a “varus condition” refers to a state of a bone or joint having an undesired inward angulation (medial angulation, that is, towards the body's midline) of the distal segment of a bone or joint. The opposite of varus is called valgus. The terms varus and valgus refer to the direction that the distal segment of the joint points. For example, a varus condition at the knee results in a bowlegged appearance with the distal part of the leg deviated inward, in relation to the femur. In a valgus condition of the knee, the distal part of the leg below the knee is deviated outward, in relation to the femur, resulting in a knock-kneed appearance. (Search “varus deformity” on Wikipedia.com Oct. 20, 2020. Modified. Accessed Jan. 6, 2020.) A varus condition can be experienced in a variety of joints, including but not limited to, ankle joints, elbow joints, foot joints, hand joints, hip joints, knee joints, toe joints, wrist joints, and the like. As used herein, a “balanced condition” refers to a state of a bone and/or joint having a desired alignment of the bone or joint with a central axis of a limb or anatomical structure that includes the bone and/or joint. In certain embodiments, a balanced condition refers to a condition of the bone or joint that is not a varus condition and is not a valgus condition.

FIG.2illustrates a balanced condition for the joint108. The superior plate118and/or pivot plate148contacts the femur102. The inferior plate120contacts the tibia104. The pivot plate148is parallel to the inferior plate120. In the illustrated embodiment, a force, or tension, in the joint108, or movement in direction of arrow164is offset by a force, or tension, in the joint108or movement in direction of arrow166. As used herein, a “tension” refers to a tensile force that is applied across an elongated structure. For example, a ligament such as a lateral collateral ligament may experience tension due to how the ligament is attached to a femur bone and tibia bone and stretched during flexing of the knee joint.

FIG.3illustrates a varus condition for a joint108. The superior plate118and/or pivot plate148contacts the femur102. The inferior plate120contacts the tibia104. The pivot plate148is not parallel to the inferior plate120. A slant in the superior plate118and/or pivot plate148can be caused by various factors, including but not limited to, an angle at which the femur102and/or tibia104has been sectioned, forces acting on the joint108by soft tissue and/or ligaments, and the like. In the illustrated embodiment, a force, or tension, in the joint108, or movement in direction of arrow164by a surface of the femur102or tibia104is greater than a force, or tension, in the joint108or movement in direction of arrow166by a surface of the femur102or tibia104.

Those of skill in the art recognize that a valgus condition can exist in the joint108illustrated inFIG.3if the superior plate118and/or pivot plate148rotates about the longitudinal axis160in the direction of arrow166. Such a slant can be caused by various factors, including but not limited to, an angle at which the femur102and/or tibia104has been sectioned, forces acting on the joint108by soft tissue and/or ligaments, and the like. In such an embodiment, a force, or tension, in the joint108, or movement in direction of arrow166by a surface of the femur102or tibia104is greater than a force, or tension, in the joint108or movement in direction of arrow164by a surface of the femur102or tibia104.

FIG.4is a posterior view of a knee joint with a gap gauge100inserted between a femur102and a tibia104.FIG.4illustrates a rear view of the gap gauge100.FIG.4shows the superior plate118, inferior plate120, separation indicator124, balance indicator126, grips132, handle134, shaft140, spring142, pivot plate148, support plate150, driver152, and fastener154. The illustrated embodiment includes a balance gauge168. In one embodiment, the balance gauge168can include a dial170and a needle172.

FIG.4illustrates medial condyles174a,174band lateral condyles176a,176bof a first bone (e.g., tibia104) and a second bone (e.g., femur102). As used herein, a “medial condyle” refers to one of the two projections on the lower extremity, distal end, of femur, the other being the lateral condyle. The medial condyle is larger than the lateral (outer) condyle due to more weight bearing caused by the center of mass being medial to the knee. (Search “medial condyle” on Wikipedia.com May 12, 2020. Modified. Accessed Jan. 6, 2020.) As used herein, a “lateral condyle” refers to one of the two projections on the lower extremity, distal end, of the femur. The other one is the medial condyle. The lateral condyle is prominent and is broader both in its front-to-back and transverse diameters. (Search “lateral condyle” on Wikipedia.com Apr. 17, 2020. Modified. Accessed Jan. 6, 2020.)

In the illustrated embodiment, the superior plate118is positionable to engage, or contact, the femur102and the inferior plate120is positionable to engage, or contact, the tibia104. The superior plate118can be shaped, or configured, to engage a medial condyle174band a lateral condyle176bof the femur102. The inferior plate120can be shaped, or configured, to engage a medial condyle174aand a lateral condyle176aof the tibia104. One example of a shape suitable of a superior plate118for engaging a medial condyle174band a lateral condyle176bof the femur102is illustrated inFIG.1C. One example of a shape suitable of an inferior plate120for engaging a medial condyle174aand a lateral condyle176aof the tibia104is illustrated inFIG.1D. Of course, the size and shape of the superior plate118and inferior plate120can be different depending on the age and size of the patient (e.g., smaller for children and larger for adults).

The balance gauge168, in one embodiment, provides a visual indication of a balance status and can provide specific information about a magnitude of imbalance or balance of the joint108to a user of the gap gauge100. As used herein, a “balance gauge” refers to an apparatus, instrument, structure, device, component, system, assembly, hardware, software, firmware, circuit, module, or logic structured, organized, configured, programmed, designed, arranged, or engineered to measure an attribute, characteristic, state, or condition of another structure or object or set of structures or objects. In one embodiment, the balance gauge is structured, organized, configured, programmed, designed, arranged, or engineered to measure a balance status between two or more structures. The balance gauge168can be connected to the balance indicator126such that movement of the balance indicator126is reflected and/or reported by the balance gauge168. In this manner, the balance gauge168can measure the balance status.

FIG.4illustrates that a user can determine both a displacement, using the separation indicator124, and a balance status, using the balance indicator126and/or the balance gauge168in a single view of the gap gauge100. This can be helpful as other soft tissue or equipment may interfere with determining either, or both, of a displacement and a balance status during an arthroplasty procedure.

FIGS.5A-5Care rear views of an exemplary gap gauge100illustrating different balance status states.FIGS.5A-5Cillustrate a dial170and a needle172coupled or connected to a balance indicator126in order to measure a balance status. As used herein, a “dial” refers to a face upon which some measurement is registered usually by means of graduations and a pointer, such as a needle. (“dial.” Merriam-Webster.com. Merriam-Webster, 2021. Web. 6 Jan. 2021. Modified.) As used herein, a “needle” refers to a long thin structure that may include a point at one end and a coupler for connecting the needle to another structure.

In the illustrated embodiment, the dial170includes marks and each mark is positioned on a face of the dial170. The marks can represent an angle of pivot, or movement, of a superior plate118and/or pivot plate148about the pin158. Each mark on the face can represent a different measure of balance status. Alternatively, or in addition, marks positioned on a face of the dial can indicate a measure of the orientation of a superior plate118relative to an inferior plate120.

In certain embodiments, the face can include numbers that identify different measures of a balance status. In one embodiment, the dial170includes marks for angles ranging from −5 degrees to +5 degrees with 0 degrees representing a balanced condition. As the superior plate118and/or pivot plate148pivot or rotate about the pin158, the rotation is measured by and conveyed to the balance indicator126. Movement of the balance indicator126transfers to the needle172and moves the needle172to point toward a mark on the face that reflects the balance status. Rotation of the superior plate118or the inferior plate120, about an anterior-posterior axis116of a patient, moves the needle172to point toward a mark on the face of the dial that reflects the orientation of the plates.

FIG.5Aillustrates an example balance gauge168of a gap gauge100that can be positioned to contact a first bone (SeeFIG.1A) and a second bone (SeeFIG.1A). Where the surfaces of the bones are parallel and/or forces within the joint108are balanced (e.g., a balance condition), a needle172of the balance gauge168may point to a middle mark of the dial170indicating a balance condition, no positive or negative degree of rotation about a pivot axis162.

FIG.5Billustrates an example balance gauge168of a gap gauge100that can be positioned to contact a first bone (SeeFIG.1A) and a second bone (SeeFIG.1A). Where the surfaces of the bones are not parallel and/or forces within the joint108are not balanced (e.g., a varus condition or valgus condition depending on which joint is being measured), a needle172of the balance gauge168may point to a mark (e.g., −5 degrees) on the left side of the middle mark of the dial170indicating an imbalance or non-balanced condition, a positive or negative degree of rotation about a pivot axis162.

FIG.5Cillustrates an example balance gauge168of a gap gauge100that can be positioned to contact a first bone (SeeFIG.1A) and a second bone (SeeFIG.1A). Where the surfaces of the bones are not parallel and/or forces within the joint108are not balanced (e.g., a varus condition or valgus condition depending on which joint is being measured), a needle172of the balance gauge168may point to a mark (e.g., +5 degrees) on the right side of the middle mark of the dial170indicating an imbalance or non-balanced condition, a positive or negative degree of rotation about a pivot axis162.

FIGS.6A-6Care rear views of an exemplary gap gauge100illustrating different displacements.FIGS.6A-6Cillustrate a superior plate118, inferior plate120, and separation indicator124. The superior plate118can include a pivot plate148and a support plate150.FIGS.6A-6Calso illustrate a driver152and a fastener154.

In the illustrated embodiment, the separation indicator124can include a face that may include a number that represents a measure for a displacement between an outer surface of the superior plate118and an outer surface of the inferior plate120. For example, in the illustrated embodiment, a number at the top-most position of the face when viewed as illustrated may represent a current amount of displacement. For example, the “9” may represent a displacement of 9 millimeters. The face on the driver152can include a plurality of different marks and/or numbers (e.g., readings) that each may represent a different displacement between the superior plate118and inferior plate120. The fastener154may permit the driver152to be rotated about a longitudinal axis of the fastener. The driver152is rotatable to a plurality of positions and each position may represent a different displacement that corresponds to the number on the face of the driver152. The illustrated embodiment can include six different displacements and six numbers each representing a different displacement. (e.g., 9, 11, 13, 15, 17, and 19).

FIG.6Aillustrates an example separation indicator124of a gap gauge100that can be positioned within an opening106between a first bone (SeeFIG.1A) and a second bone (SeeFIG.1A). Once positioned, and the separator122is actuated to a desired displacement, a user can read the displacement by reading the number in the top-most position on the separation indicator124. For example, inFIG.6Athe displacement is nine millimeters. For example, inFIG.6Bthe displacement is fifteen millimeters. For example, inFIG.6Cthe displacement is nineteen millimeters.

The separator122can be actuated to bring the superior plate118in contact with a resected surface of a femur102and the inferior plate120in contact with a resected surface of a tibia104. As used herein, a “resected surface” refers to an outermost part or layer of a body structure that is exposed after a resection procedure. As used herein, a “resection” refers to a method, procedure, or step that removes tissue from another anatomical structure or body. A resection is typically performed by a surgeon on a part of a body of a patient. (Search “surgery” on Wikipedia.com May 26, 2021. CC-BY-SA 3.0 Modified. Accessed May 26, 2021.) Resection may be used as a noun or a verb. In the verb form, the term is “resect” and refers to an act of performing, or doing, a resection. Past tense of the verb resect is resected.

The superior plate118can be shaped, or configured, to facilitate contact with a resected surface of the femur102. The inferior plate120can be shaped, or configured, to facilitate contact with a resected surface of the tibia104. One example of a shape suitable for the superior plate118is illustrated inFIG.1C. One example of a shape suitable for the tibia104is illustrated inFIG.1D.

The separator122may be actuated by securing the handle134with one hand and then rotating the driver152to one or more of a plurality of displacement positions. Alternatively, or in addition, actuation of the separator122may include securing the gap gauge100in position using the handle134, rotating the driver152, and/or pulling on the grips132to separate the plates118,120. If the handle134is secured, the driver152rotated and the grips132pulled to separate the plates118,120simultaneously or at about the same time an assistant may help with the actuation.

FIG.7is a perspective view of an example gap gauge100.FIG.7illustrates a gap gauge100that includes a separator122that includes a cam702and a follower704. As used herein, a “cam” refers to a mechanical device structured, organized, configured, programmed, designed, arranged, or engineered to translate motion of one form into motion of another form. For example, a cam can translate rotary motion into linear motion. Similarly, a cam can translate linear motion into rotary motion. A cam can be a rotating or sliding piece in a mechanical linkage used in transforming rotary motion into linear motion. A cam can be a part of a rotating wheel (e.g. an eccentric wheel) or shaft (e.g. a cylinder with an irregular shape) that strikes or moves a lever at one or more points on the rotating wheel's circular path. The cam can be a simple tooth or an eccentric disc or other shape that produces a smooth reciprocating (back and forth) motion in the follower, which is a lever configured to make contact with the cam. (Search “cam” on Wikipedia.com Dec. 26, 2020. Modified. Accessed Jan. 6, 2020.) Various types of cams can be used with the present disclosure. For example, the cam can be a radial cam, a disc cam, a cylindrical cam, or the like.

As used herein, a “follower” refers to a rigid structure that contacts a cam lobe profile. In one embodiment, the follower may translate motion of the cam to the follower and/or a structure connected to the follower. In certain embodiments, as the cam rotates the follower may slide along a contacting surface of the cam to thereby convert the rotary motion into a linear motion. A follower may also be referred to as a “cam follower” or “track follower.” A cam follower is a type of structure, roller, or needle bearing designed to follow and/or contact a cam lobe profile of the cam. (Search “cam follower” on Wikipedia.com Nov. 13, 2020. Modified. Accessed Jan. 6, 2020.)

Various kinds of followers can be used in the present disclosure. The type and shape of a cam follower may be based on the kind of surface of the follower (referred to as a follower face) that contacts a contacting surface of the cam. In one embodiment, the follower is a stud that comes to a point to form a knife edge follower. Alternatively, or in addition, the follower face can have a variety of other shapes including, but not limited to a flat face, a mushroom face, a cylindrical face, a curved face, a semispherical face, and the like. In addition, the follower can include a roller on the end that contacts the contacting surface of the cam. The roller on the end of the follower can enable the follower to roll and or slide along the contacting surface of the cam.

In the illustrated embodiment, the cam702is connected to, or integrated with, the driver152. The driver152connects to the inferior body138by way of the fastener154. In this manner, the cam702connects to the inferior body138. The cam702includes a contacting surface706. As used herein, a “contacting surface” refers to a surface of a cam that contacts a follower. The orientation, placement, and position of the contacting surface can vary with the type of cam being used. In embodiments that use a radial cam the radial cam can have a central axis708and the contacting surface can be a surface of the cam that follows a circumference of the radial cam about the central axis708.

Rotation of the driver152also rotates the cam702. Rotation of the cam702moves the superior body136which adjusts the displacement of the superior plate118relative to the inferior plate120. In one embodiment, the cam702is a radial cam and rotates about a common axis, the central axis708, with the fastener154. As used herein, a “radial cam” refers to a type of cam in which the cam has a central axis, and the contacting surface follows a circumference of the cam about the central axis. In a radial cam, the follower moves in a linear motion in a direction perpendicular to the central axis. The follower704can contact, or rest, on the cam702.

The follower704is connected to the superior body136. In one embodiment, the follower704may be biased against the contacting surface706by the spring142around the shaft140. The follower704is sized and shaped to move the superior body136along the shaft140relative to the inferior body138as the follower704slides along, or is positioned along, the contacting surface706.FIG.7illustrates one example embodiment, in which the support plate150couples to the separator122(e.g., by way of the cam702, follower704, and superior body136) such that actuation of the separator122moves the support plate150vertically relative to the inferior plate120.

FIG.7also illustrates one embodiment of a driver152that includes holes710, or pockets, around the circumference of the driver152. When the gap gauge100is used, a user may insert rods into the holes710to provide leverage for rotating the driver152.

FIG.8Ais a front view of a driver152of a gap gauge100, according to one embodiment of the present disclosure.FIG.8Aillustrates the separation indicator124, the driver152, the central axis708, and an opening802. The opening802may be an area between an outer surface of the driver152and a head of the fastener154. The opening802may have a polygonal cross-sectional shape. In the illustrated embodiment, the opening802is has a hexagon cross-sectional shape. The opening802may be sized and configured to receive a shaft or drive head of a separate tool such as a wrench (not shown). A user may use the wrench in the opening802to achieve a mechanical advantage in rotating the driver152about the central axis708.

FIG.8Bis a rear view of a driver152and cam702of a gap gauge100, according to one embodiment of the present disclosure.FIG.8Billustrates that the cam702may have an irregular radius that varies about the central axis708. The length of the radius about the central axis708may be designed or engineered to achieve or maintain a desired displacement between the superior plate118and inferior plate120connected to the cam702and the follower704.

FIG.9illustrates an exploded view of an exemplary gap gauge100, according to one embodiment of the present disclosure.FIG.9illustrates details about how the hinge156, pin158, and needle172can cooperate to provide a balance indicator126. In certain embodiments, the balance indicator126includes a lock-out mechanism130that can prevent rotation of the pivot plate148relative to the inferior plate120and/or the support plate150when the lock-out mechanism130is in a set configuration.

FIG.9illustrates a support plate150that includes a knuckle902and openings904a,904bfor at least one corresponding knuckle of the pivot plate148. The knuckle902can connect the support plate150to the hinge156and the pivot plate148. In such an embodiment, the support plate150and the pivot plate148can each serve as leaves of the hinge156. When assembled, one or more knuckles of the pivot plate148align with one or more knuckles902of the support plate150and receive the pin158. In this manner, the pivot plate148, the pin158, and the support plate150serve as a hinge to implement one embodiment of a balance indicator126.

In certain embodiments, the pivot plate148may rotate freely about the pin158. In such an embodiment, the pin158may include one or more pins906. The pins906engage the pin158and the pivot plate148such that rotation of the pivot plate148causes rotation of the pin158. In addition, if the pin158is fixed, or prevented from rotating about the pivot axis162, the pins906may also retain the pivot plate148from rotating.

The pin158can extend within the superior body136and couple to the needle172. In this manner, rotation of the pin158causes the needle172to move and point in a different direction. In certain embodiments, the pin158may pass through a slot in the post146to enable both rotation of the pin158and movement of the pin158away from the inferior body138when the gap gauge100is used.

FIG.9illustrates a lock-out mechanism130that can include a set screw908. The set screw908has threads that engage with threads of an opening910in the superior body136. Moving the set screw908into the opening910activates the lock-out mechanism130and prevents rotation of the pin158and connected pivot plate148. Moving the set screw908out of the opening910deactivates the lock-out mechanism130and permits rotation of the pin158and connected pivot plate148.

As used herein, a “set screw” refers to a type of screw generally used to secure a first object within, or against, second object, usually without using a nut. Set screws can be headless, meaning that the screw is fully threaded and has no head projecting past the thread's major diameter. If a set screw does have a head, the thread may extend to the head. A set screw can be driven by an internal-wrenching drive, such as a hex socket (Allen), star (Torx), square socket (Robertson), or a slot. A set screw can be driven by a knob on or part of a head of the set screw. The knob may be sized to facilitate rotation by a user using their fingers and may be referred to as a thumb screw. In one embodiment, the set screw passes through a threaded hole in the second object (an outer object) and is tightened against the first object (an inner object) to prevent the inner object from moving relative to the outer object. The set screw can exert a compressional and/or clamping force through an end of the set screw that projects through the threaded hole. (Search “set screw” on Wikipedia.com Aug. 17, 2020. Modified. Accessed Jan. 6, 2020.)

FIG.10Ais a perspective view of a pin158of the gap gauge100ofFIG.1A, according to one embodiment of the present disclosure. The pin158may be a cylindrical structure with a longitudinal axis160. The pin158can include a proximal end1002, a distal end1004, and a middle1006. In one embodiment, the proximal end1002connects to a balance gauge168. For example, the proximal end1002may include a D-shaped cross section that includes a flat part1008. In one embodiment, the D-shaped cross-section of the proximal end1002may be sized to accept a D-shaped opening in a needle172that can be slide over the proximal end1002and positioned for a balance indicator126and/or a balance gauge168.

The distal end1004may serve as a pivot for a hinge156of the gap gauge100. Alternatively, or in addition, the distal end1004may serve as a pivot for the balance indicator126. The pivot may align with the longitudinal axis160. In addition, the distal end1004and/or the middle1006may include one or more keyed sections1010. In one embodiment, the keyed sections1010may be used for the pins906to connect the pin158to the pivot plate148.

In one embodiment, the middle1006may include a section1012that includes a planar surface1014. The planar surface1014of the section1012may serve as part of the lock-out mechanism130. For example in one embodiment, the set screw908may bias against the planar surface1014of the pin158to prevent rotation of the pin158. In the illustrated embodiment, the section1012has a D-shaped cross-section. In one embodiment, the D-shaped cross-section of the section1012may be offset 90 degrees from a D-shaped cross-section of the proximal end1002that includes the flat part1008. In one example embodiment, the 90-degree offset enables a needle172to register/measure no imbalance when the lock-out mechanism130is activated to prevent rotation of the pin158.

FIGS.10B and10Care side views of the pin158ofFIG.10A, according to one embodiment of the present disclosure.FIG.10Billustrates and embodiment of a pin158that includes a first section1016having a larger diameter than a second section1018.

FIGS.11A and11Bare perspective views of a lock-out mechanism130of a gap gauge100, according to one embodiment of the present disclosure.FIG.11Aillustrates the lock-out mechanism130when the set screw908is in a set configuration.FIG.11Billustrates the lock-out mechanism130when the set screw908is in an unset configuration. As used herein, a “set configuration” refers to an arrangement and/or relationship between a set screw and a pin such that the set screw prevents rotation of the pin about a longitudinal axis of the pin. In the set configuration, the set screw908has been advanced within the opening910to engage the planar surface1014of the section1012.

As used herein, an “unset configuration” refers to an arrangement and/or relationship between a set screw and a pin such that the set screw permits rotation of the pin about a longitudinal axis of the pin. In the unset configuration, the set screw908has been retracted within the opening910to disengage the planar surface1014of the section1012.

FIG.12illustrates a flowchart for a method1200for measuring a gap and/or balance status between a femur and a tibia of a patient, according to one embodiment of the present disclosure. In general, the method1200may include the use of gap gauge that includes both a separation indicator and a balance indicator126. In certain embodiments, the gap gauge may also include a balance gauge.

The method1200may begin with a step1210in which a first plate (e.g., inferior plate120) and a second plate (e.g., superior plate118) of a gap gauge may be inserted between a femur and a tibia. In certain embodiments, the gap gauge may be positioned such that a pivot axis of a hinge may be aligned with an anterior-posterior axis of a patient.

Once the gap gauge is positioned, the method1200may proceed to step1220in which the first plate and second plate are actuated apart such that the first plate contacts a resected surface of the femur and the second plate contacts a resected surface of the tibia.

Once the first plate and second plate have been actuated apart, the method1200may proceed to step1230in which a separation indicator of the gap gauge may be read to obtain a displacement between the femur and the tibia. Once the displacement has been read, the method1200may proceed to step1240in which a balance indicator of the gap gauge is read to obtain a balance status between the femur and the tibia.

A surgeon using the example gap gauge100may use the displacement amount and/or the balance status to choose from a set of prosthesis available for an arthroplasty procedure. In one example, a surgeon may choose a different prosthesis than one pre-operatively selected based on the balance status reported/measured by the balance indicator126and/or the example balance gauge168. The different prosthesis may be selected to compensate for the balance status reported/measured by the balance indicator126and/or the example balance gauge168. If a compensating prosthesis is selected, the surgeon may not need to make any changes to the joint108to accomplish a desired balance condition.

In another example, if the balance status indicates a varus condition, a first prosthesis may be selected during the procedure. If the balance status indicates a valgus condition, a second prosthesis may be selected during the procedure. Alternatively, or in addition, the displacement and/or balance status may be used by a surgeon to determine whether to do further resection of the femur102and/or tibia104, whether to release one or more of the medial collateral ligament and the lateral collateral ligament, or take other steps of the arthroplasty procedure in an effort to accomplish a desired outcome for the arthroplasty procedure.

Once the displacement and the balance status has been read, the method1200may proceed to step1250in which tension applied to the femur and/or the tibia by a medial collateral ligament and/or a lateral collateral ligament is adjusted. Once the tension applied to the femur and/or the tibia is adjusted, the method1200may proceed to step1260in which the balance indicator of the gap gauge is read to obtain an adjusted balance status between the femur and the tibia in response to adjusting the tension. After reading the adjusted balance, the method1200may end with the balance of the joint having the desired balance status.

Alternatively, or in addition thereto, the method1200may proceed to a step in which a tension applied to the femur and the tibia by one or more of a medial collateral ligament and a lateral collateral ligament may be adjusted and the balance indicator of the gap gauge may be read to obtain an adjusted balance status between the femur and the tibia in response to adjusting the tension.

Alternatively, or in addition thereto, once tension applied to the femur and the tibia by one or more of a medial collateral ligament and a lateral collateral ligament is adjusted, the method1200may proceed to a step in which one or more of the medial collateral ligament and the lateral collateral ligament are released while the gap gauge remains between the femur and the tibia and remains actuated.

Alternatively, or in addition thereto, once tension applied to the femur and the tibia by one or more of a medial collateral ligament and a lateral collateral ligament is adjusted, the method1200may proceed to a step in which the gap gauge is removed from between the femur and the tibia. Once the gap gauge is removed from between the femur and the tibia, the method1200may proceed to a step in which one or more of the resected surface of the femur and the resected surface of the tibia is resected. Once one or more of the resected surface of the femur and the resected surface of the tibia are resected, the method1200may proceed to a step in which the first plate and the second plate of the gap gauge is re-inserted between the femur and the tibia. Once the first plate and the second plate of the gap gauge is re-inserted between the femur and the tibia, the method1200may proceed to a step in which the first plate and the second plate are actuated apart such that the first plate is in contact with the resected surface, or further resected surface, of the femur and the second plate is in contact with the resected surface, or further resected surface, of the tibia. Once the first plate and second plate are actuated apart, the method1200may proceed to a step in which the separation indicator of the gap gauge is read to obtain the displacement between the femur and the tibia. Once the displacement is obtained, the method1200may proceed to a step in which the balance indicator of the gap gauge is read to obtain the balance status between the femur and the tibia.

FIG.13is a perspective view of an exemplary gap gauge1300, according to one embodiment of the present disclosure. In one embodiment, the exemplary gap gauge1300may generally include a first plate and a second plate. In the illustrated embodiment, the first plate may be an inferior plate120and the second plate may be a superior plate118. The superior plate118may include a pivot plate148and a support plate150. The first plate120can be positioned in contact with a first bone, such as a tibia and the second plate118can be positioned in contact with a second bone, such as a femur. In one embodiment, the first plate and the second plate are sized for insertion between a first bone that is a tibia and a second bone that is a femur. The superior plate118, inferior plate120, pivot plate148, and support plate150may be similar in structure, performance, and/or operation to like numbered components in other embodiments previously described.

The exemplary gap gauge1300may also generally include a separator122, a separation indicator124, a balance indicator126, a handle134(not shown inFIG.13), a superior body136, and an inferior body138similar in structure, performance, and/or operation to like numbered components in other embodiments previously described.

In one embodiment, the exemplary gap gauge1300includes a pin guide1302. As used herein, a “guide” refers to a part, component, or structure designed, adapted, configured, or engineered to guide or direct one or more other parts, components, or structures. A guide may be part of, integrated with, connected to, attachable to, or coupled to, another structure. In one embodiment, a guide may include a modifier that identifies a particular function, location, orientation, operation, type, and/or a particular structure of the guide. Examples of such modifiers applied to a guide, include, but are not limited to, “pin guide” that guides or directs one or more pins, a “cutting guide” that guides or directs the making or one or more cuts, and the like.

The pin guide1302can be connected and/or connectable to one of the second plate (e.g. superior plate118) and the first plate (e.g. an inferior plate120). The pin guide1302can include at least one pin hole1304. Each pin hole1304may be configured to receive a pin1306. A first pin hole can be positioned, sized, and configured to guide the insertion of a first pin1306ainto a bone (e.g., a femur102). In one embodiment, the pin guide1302includes an attachment feature1308. The attachment feature1308enables the exemplary gap gauge1300to have the pin guide1302attached or detached as desired or needed.

As used herein, a “pin hole” refers to a hole, void, opening, channel, space, or passage that extends from one side of a structure to another side of the structure. In certain embodiments, a pin hole is straight. A pin hole may have a circular or oval cross section. In certain embodiments, a pin hole is configured to accept a pin. A diameter of a pin hole may be just larger than a cross-sectional diameter of a pin such that the pin fits within the pin hole in a friction fit or a loose fit. In certain embodiments, a pin hole can include a beveled or chamfered edge at one or both openings of the pin hole. A pin hole may serve to accept alignment pins, attachment pins, securement pins or the like. Pins within the pin hole may sit within the pin hole temporarily during a procedure or permanently as part of procedures. Pin holes can be used in a variety of devices, components, apparatus, and systems, including but not limited to, fixation plates, measurement instruments, pin guides, cutting guides, and the like.

As used herein, an “pin” refers to an elongated structure. In certain embodiments, a pin can be configured to support a load (including a tension, compression, shear, torsion, and/or bending load). In certain embodiments, a pin may be a thin cylindrical structure. A pin can serve a variety of functions and may include a modifier identifying a particular function for example certain solutions may use alignment pins, attachment pins, securement pins, or the like. Pins may serve a temporary or permanent structural purpose. Pins can be used in a variety of devices, components, apparatus, and systems, including but not limited to, fixation plates, measurement instruments, pin guides, cutting guides, surgical instrumentation, and the like. A pin can have a variety of geometric cross-sectional shapes, including, but not limited to a circle, an ellipse, an ovoid, or other circular or semi-circular shape, as well as a rectangle, a square, or other polygon. A pin has two ends one end can be blunt and the other end may come to a point. A pin can be made from a variety of materials including, metal, plastic, ceramic, wood, fiberglass, or the like. A pin may also be formed of any biocompatible materials, including but not limited to biocompatible metals such as Titanium, Titanium alloys, stainless steel alloys, cobalt-chromium steel alloys, nickel-titanium alloys, shape memory alloys such as Nitinol, biocompatible ceramics, and biocompatible polymers such as Polyether ether ketone (PEEK) or a polylactide polymer (e.g. PLLA) and/or others.

As used herein, “feature” refers to a distinctive attribute or aspect of something. (Search “feature” on google.com. Oxford Languages, 2021. Web. 20 Apr. 2021.) A feature may include a modifier that identifies a particular function or operation and/or a particular structure relating to the feature. Examples of such modifiers applied to a feature, include, but are not limited to, “attachment feature,” “securing feature,” “alignment feature,” “adjustment feature,” “guide feature,” “protruding feature,” “engagement feature,” “disengagement feature,” and the like.

In the illustrated embodiment, the pin guide1302includes two pin holes1304each configured to guide a pin1306a,binto a bone (e.g., a femur102). In certain embodiments, the pins1306may be parts of an exemplary gap gauge1300. Alternatively, or in addition, the pins1306may be part of a kit or assembly such as a gap measurement and correction assembly for facilitating an arthroplasty procedure on a femur and a tibia of a patient. In certain embodiments, the gap measurement and correction assembly may also include a cutting guide.

As used herein, an “assembly” refers to a collection, set, or kit of two or more structures, components, parts, systems, and/or sub-systems that together may be used, connected, coupled, applied, integrated, or adapted to be used to perform one or more functions and/or features. An assembly may include a modifier that identifies one or more particular functions or operations that can be accomplished using the assembly. Examples of such modifiers applied to an assembly, include, but are not limited to, “measurement assembly,” “correction assembly,” “fixation assembly,” “separation assembly,” “cutting assembly,” and the like.

In one embodiment, the proposed solution is a gap measurement and correction assembly for facilitating an arthroplasty procedure on a femur and a tibia of a patient. The assembly may include an exemplary gap gauge1300, a cutting guide and optionally one or more pins1306. The exemplary gap gauge1300may include a superior plate118, inferior plate120, separator122, a balance indicator126, and a pin guide1302. The balance indicator126connects to one of the superior plate and the inferior plate and indicates a nonparallel orientation of the superior plate118relative to the inferior plate120. As used herein, “orientation” refers to a direction, angle, position, condition, state, or configuration of a first object, component, part, apparatus, system, or assembly relative to another object, component, part, apparatus, system, or assembly. As used herein, “nonparallel orientation” refers to two structures that are oriented in a nonparallel configuration with respect to each other.

In one embodiment, a pin guide1302of an assembly guides insertion of a first pin into either one of a tibia and a femur of a patient. The first pin1306aand/or a second pin1306bcan be used to attach, or connect, a cutting guide to one of the tibia and the femur. The cutting guide is designed to guide resection of the tibia or the femur having the inserted pin(s)1306a,b. In one embodiment, the cutting guide is configured to counter a nonparallel orientation of the superior plate118relative to the inferior plate120. Alternatively, or in addition, the pin guide1302may be configured to counter a nonparallel orientation of the superior plate118relative to the inferior plate120.

FIGS.14A-14Dillustrate are a rear view, perspective side views, and a front perspective view, respectively of the pin guide1302ofFIG.13, according to one embodiment of the present disclosure. An exemplary gap gauge1300may include a variety of designs for a pin guide1302that is coupled or connected to the exemplary gap gauge1300.

In one embodiment, the pin guide1302includes a base1310, an arm1312, and a mast1314. The base1310, arm1312, and/or mast1314cooperate to position one or more pin holes1304for pins1306used in an arthroplasty procedure.

The base1310serves as a structural connection for the pin guide1302to the exemplary gap gauge1300. As used herein, a “base” refers to a main or central structure, component, or part of a structure. A base is often a structure, component, or part upon which, or from which other structures extend, are coupled to, or connect to. A base may have a variety of geometric shapes and configurations. A base may be rigid or pliable. A base may be solid or hollow. In one embodiment, a base may include a housing, frame, or framework for a larger system, component, structure, or device.

In one embodiment, the base1310is shaped, sized, and designed to connect the pin guide1302to a second plate, such as a superior plate118. For example, in one embodiment, the base1310includes an arcuate section that can facilitate mating the base1310to a section of a second plate, such as a superior plate118.

The arm1312includes one or more pin holes1304. In one embodiment, the pin holes1304are parallel with each other. As used herein, an “arm” refers to an elongated structure that extends from another structure such as a base or a body. In certain embodiments, an arm can be configured to support a load (including a tension, compression, shear, torsion, and/or bending load). In certain embodiments, an arm may comprise a generally planar structure. An arm can be a separate structure connected to, or integrated with, another structure. Based on how the arm connects to or extends from another structure, such as a base or body, the arm can resemble an arm of a human or animal in that the arm can be an appendage to another structure. An arm can be two-dimensional or three-dimensional and can have a variety of geometric shapes and/or cross-sectional shapes, including, but not limited to a rectangle, a square, or other polygon, as well as a circle, an ellipse, an ovoid, or other circular or semi-circular shape. An arm can be made from a variety of materials including, metal, plastic, ceramic, wood, fiberglass, or the like. One arm may be distinguished from another based on where the arm is positioned within a structure, component, or apparatus.

The mast1314extends from the base1310and connects the base1310and the arm1312. As used herein, a “mast” refers to an elongated structure that extends from another structure such as a base or a body. In certain embodiments, a mast can be configured to support one or more other structures that connect to or extend from the mast. A mast can be configured to support a load (including a tension, compression, shear, torsion, and/or bending load). In certain embodiments, a mast may comprise a cylindrical structure. A mast can be a separate structure connected to, or integrated with, another structure. A mast can have a variety of geometric shapes and/or cross-sectional shapes, including, but not limited to a rectangle, a square, or other polygon, as well as a circle, an ellipse, an ovoid, or other circular or semi-circular shape. A mast can be made from a variety of materials including, metal, plastic, ceramic, wood, fiberglass, or the like.

In one embodiment, the mast1314can extend in a superior direction when the exemplary gap gauge1300is being used on a patient's knee. Alternatively, the mast1314can extend in an inferior direction when the exemplary gap gauge1300is being used on a patient's knee. The direction and manner that the mast1314extends may be determined by how the mast1314connects to the base1310and/or how the base1310connects to one or more plates of an exemplary gap gauge1300.

The arm1312can include a first segment1316and a second segment1318. In one embodiment, the first segment1316is a different length than the second segment1318. Alternatively, the first segment1316and second segment1318can be substantially the same length. In the illustrated embodiment, the first segment1316includes two pin holes1304and the second segment1318includes two pin holes1304. Those of skill in the art recognize that the first segment1316and second segment1318can have various numbers of pin holes1304. In one embodiment, the exemplary gap gauge1300is configured for use on either a left knee or a right knee. Consequently, depending on the knee being used the first segment1316may extend in a medial direction from the mast1314, and thus a medial side of a knee, or a lateral direction from the mast1314, and thus a medial side of a knee when the exemplary gap gauge1300is placed within a gap between a femur and a tibia.

The pin holes1304can be used in a variety of ways for different arthroplasty procedures. For example, a first pin hole1304awithin a first segment1316and a second pin hole1304bin a second segment1318may be used to position and place pins1306for a particular arthroplasty procedure. When the exemplary gap gauge1300is positioned anterior to a left knee the first segment1316may extend toward the medial side of the knee and the second segment1318may extend toward the lateral side of the knee. Of course, the sides may be reversed when the exemplary gap gauge1300is used on a right knee.

In such an example, the first pin hole1304aand second pin hole1304bmay serve to position pins1306within a bone, such as a femur or a tibia. In one embodiment, first pin hole1304aand second pin hole1304bposition pins1306within a femur (e.g., a second bone) in a manner that conveys, or communicates, a balance status of a knee by way of placement of the pins1306. In one embodiment, the pin guide1302, first pin hole1304a, and second pin hole1304bcooperate to align a first pin1306aand a second pin1306bwith each other at an orientation relative to second plate (e.g., a superior plate118connected to the pin guide1302) that matches the balance status of the knee. In this manner, the balance status can be transferred from the exemplary gap gauge1300to one of the bones, such as a femur.

Placement of the first pin1306aand a second pin1306bin one of the bones, such as a femur, enables coupling of a cutting guide to a bone, such as a femur. For example, holes in the cutting guide may permit the cutting guide to slide over the pins1304a,band contact the bone (e.g., femur). In this manner, the first pin1306aand a second pin1306bcommunicate a balance status from the exemplary gap gauge1300to the cutting guide.

Other pin holes, such as a third pin hole1304cand/or a fourth pin hole1304dmay be used in the same arthroplasty procedure on the same patient. For example, third pin hole1304cand/or a fourth pin hole1304dmay serve as alternative or additional pin placement locations in situations where a bone does not securely engage a pin due to conditions like osteoporosis. In another example, third pin hole1304cand/or a fourth pin hole1304dmay serve as pin placement locations for patients of different ages or genders.

FIGS.14B and14Cillustrate perspective side views of a pin guide1302in accordance with one embodiment. In one embodiment, the pin guide1302can be connected to a plate (e.g., superior plate118, inferior plate120, pivot plate148, and/or support plate150). For example, a attachment feature1308may include a hole in the base1310and a corresponding hole in a plate and a pin that can be inserted into both holes to secure the pin guide1302to the plate. Alternatively, or in addition, the attachment feature1308may enable the pin guide1302can be removably coupled to the exemplary gap gauge1300.

Referring now toFIG.14D, for example, the pin guide1302may include an attachment feature1308that enables the pin guide1302to be removably coupled to one or more of the plates of an exemplary gap gauge1300(e.g., superior plate118, inferior plate120, pivot plate148, and/or support plate150). The attachment feature1308may include a hole in the base1310and a hole in a plate. The holes may include internal threads configured to engage external threads of a set screw1320. The set screw1320may be similar to the screw908described earlier. Rather than contacting a pin, the set screw1320may engage a threaded hole in the plate to removably couple the pin guide to the plate.

Those of skill in the art will appreciate that the pin guide1302can be coupled or connected to different plates of the exemplary gap gauge1300and may extend from the exemplary gap gauge1300in a superior direction or an inferior direction when the exemplary gap gauge1300is in use.

In the illustrated embodiment, ofFIG.14D, the attachment feature1308removably couples the pin guide1302to a second plate, a superior plate118, such that the pin guide1302guides insertion of a first pin1306a(through first pin hole1304a) into a second bone, such as a femur102such that the first pin1306ais placed in the femur102according to the balance status between a first plate, an inferior plate120, and the second plate, the superior plate118. In such an embodiment, the pin guide1302may extend in a superior direction when the exemplary gap gauge1300is in use.

Specifically, the first pin1306acan be placed in the femur102at a location that reflects the balance or imbalance of a gap in the knee. Because the pin guide1302is connected to the superior plate118, and the superior plate118can pivot using the hinge156, the pin can be placed in a position that reflects the balance, or imbalance, of the gap. Furthermore, a pin guide1302that includes a second pin hole1304bfor placement of a second pin1306b, enable the placement of a first pin1306aand a second pin1306bparallel to each other in an orientation and/or relationship that reflects the balance status of the gap. Such orientation and/or relationship can be referred to as a nonparallel orientation.

As used herein, “imbalance” refers to a state or condition in which two opposing factors, features, attributes, aspects, conditions, or states are not balanced. “Imbalance” also refers to a lack of proportion or relation between corresponding things, structures, components, angles, or vectors. (Search “imbalance” on google.com. Oxford Languages, 2021. Modified. Web. 26 May 2021.) Examples of opposing factors, features, attributes, aspects, conditions, or states that can be imbalanced includes a varus condition and a valgus condition, a motive force and a friction force, and the like.

In another embodiment, the attachment feature1308may removably couple the pin guide1302to a second plate, a superior plate118, such that the pin guide1302guides insertion of a first pin1306a(through first pin hole1304a) into a first bone, such as a tibia104such that the first pin1306ais placed in the tibia104according to the balance status between a first plate, an inferior plate120, and the second plate, the superior plate118. In such an embodiment, the pin guide1302may extend in an inferior direction when the exemplary gap gauge1300is in use.

Specifically, the first pin1306acan be placed in the tibia104at a location that reflects the balance, or imbalance, of a gap in the knee. Because the pin guide1302is connected to the superior plate118, and the superior plate118can pivot using the hinge156, the pin can be placed in a position that reflects the balance, or imbalance, of the gap. Furthermore, a pin guide1302that includes a second pin hole1304bfor placement of a second pin1306b, enable the placement of a first pin1306aand a second pin1306bparallel to each other in an orientation and/or relationship that reflects the balance status of the gap. Such orientation and/or relationship can be referred to as a nonparallel orientation.

FIG.15is a top view of an exemplary gap gauge1300ofFIG.13, according to one embodiment of the present disclosure. The exemplary gap gauge1300includes a pin guide1302with two pins1306passing through corresponding pin holes in the pin guide1302. In certain embodiments, the two pins1306may be long enough to facilitate securing them in one of a femur102and a tibia104. In the illustrated embodiment, the pin guide1302can be connected to the superior plate118and extend above the superior plate118to position the pins1306in a femur102. Alternatively, the pin guide1302can be connected to the superior plate118and extend below the superior plate118and inferior plate120to position the pins1306in a tibia104.

FIG.15also illustrates an attachment feature1308embodied using a set screw1320and corresponding threaded holes that can connect the pin guide1302to one or more of the plates. In various embodiments, the set screw1320can connect the pin guide1302to a superior plate118, such as a pivot plate148and/or support plate150or to an inferior plate120.

FIGS.16A and16Bare side perspective views of a pin guide1302ofFIG.13, according to embodiments of the present disclosure.FIGS.16A and16Billustrate two alternative embodiments of an attachment feature1308that can be used. InFIG.16A, an attachment feature1308embodied as a set screw1320can be used to removably couple the pin guide1302to a second plate, such as superior plate118, such that the pin guide guides insertion of one or more pins into a bone according to a balance status between a first plate and a second plate. InFIG.16B, an attachment feature1308embodied as a pin and corresponding hole(s) can be used to couple the pin guide1302to a second plate, such as superior plate118, such that the pin guide guides insertion of one or more pins into a bone according to a balance status between a first plate and a second plate.

FIGS.16A and16Balso illustrate how a base1310of a pin guide1302can be configured to interface with an opening in a plate as the pin guide1302couples to the plate. For example, the base1310may be shaped to fit within a corresponding opening in a superior plate118.

FIG.17Ais a perspective view of a gap gauge1300inserted between two bones, according to one embodiment of the present disclosure.FIG.17Aillustrates one stage of one possible arthroplasty procedure according to one embodiment of the present disclosure.FIGS.17B-17Dillustrate subsequent exemplary stages of a possible arthroplasty procedure according to one embodiment of the present disclosure.

FIG.17Aillustrates a three-dimensional axis1710. The three-dimensional axis1710includes a cephalad-caudal axis112, a medial-lateral axis114, and an anterior-posterior axis116as described above. The three-dimensional axis110is used to identify how a gap gauge1300is positioned and/or oriented with respect to an anterior-posterior axis116and cephalad-caudal axis112of a patient who is in a reference anatomical position.

FIG.17Aillustrates a posterior perspective view of a knee joint108in extension, such as a left knee. The exemplary gap gauge1300can be inserted into an opening106by moving the exemplary gap gauge1300along the anterior-posterior axis116. Once inserted, the exemplary gap gauge1300may be actuated to measure a size of the opening106. The exemplary gap gauge1300may be actuated by engaging the superior plate118with a resected surface of a femur102and the inferior plate120with a resected surface of a tibia104. In one embodiment, the inferior plate120is a first plate and the superior plate118is a second plate. The first plate and the second plate may be sized for insertion between the first bone which may be a tibia and the second bone which may be a femur. With the superior plate118and inferior plate120engaging the bones, an operator can determine a balance status by examining a balance indicator126.

At this stage in a procedure, a surgeon can determine whether further resection of one, or the other, or both of the bones is desired. If resection is desired, an operator may pass, or insert, pins1306through the pin holes1304and into one of a medial condyle and a lateral condyle of the bone. In the illustrated embodiment, the operator may pass one pin1306through the pin guide1302and into a lateral condyle176bof the femur102and another pin1306through the pin guide1302and into a medial condyle174bof the femur102. The pins1306may be pressed, pushed, forced, or driven into the femur102such that the pins1306are secured to the femur102.

Advantageously, the pin guide1302aligns the pins1306with each other such that the pins1306are parallel when engaging the femur102. In embodiments in which the pin guide1302is coupled to the superior plate118and pivots in accordance with the balance status, the parallel pins1306align with each other at an orientation relative to the superior plate118that matches the balance status.

FIG.17Bis a perspective view of two pins1306in one of the bones ofFIG.17A, according to one embodiment of the present disclosure.FIG.17Billustrates a subsequent stage of one possible arthroplasty procedure according to one embodiment of the present disclosure. In this stage, an operator may remove the exemplary gap gauge1300by, for example by sliding the pin guide1302off the pins1306by moving the exemplary gap gauge1300in the anterior direction along the anterior-posterior axis116. Alternatively, or in addition, an operator may drive the pins1306into the bone to create a mark, or pilot hole, in the bone. Next, the operator may remove the pins1306and the exemplary gap gauge1300and then replace the pins1306in the pilot holes made in the bone.

FIG.17Cis a perspective view of a cutting guide1720engaging the two pins1306in one of the bones ofFIG.17A, according to one embodiment of the present disclosure.FIG.17Cillustrates a subsequent stage of an arthroplasty procedure according to one embodiment of the present disclosure. In this stage, an operator may slide a cutting guide1720along the pins1306by coupling the pins1306with an alignment feature. In one example, an operator may pass the pins1306through an alignment feature, such as holes in the cutting guide1720, and move the cutting guide1720in the posterior direction along the anterior-posterior axis116until the cutting guide1720contacts the bone, femur102. In one embodiment, the pins1306are aligned with each other and positioned on the femur102in an orientation that represents the balance status of the joint108. By coupling the cutting guide1720to the bone, femur102, using the pins1306, the balance status of the joint108is communicated to the cutting guide1720.

FIG.17Dis a front perspective view of the cutting guide1720secured to one of the bones (e.g., a femur102) ofFIG.17A, according to one embodiment of the present disclosure. In one embodiment, the cutting guide1720may include an alignment feature1722, securing feature1724, and guide feature1726.FIG.17Dillustrates a subsequent stage to the stage illustrated inFIG.17C. In one embodiment, the securing feature1724may include holes in a cutting guide1720and securing pins1728.

Prior to the stage illustrated inFIG.17D, an operator may pass pins, such as securing pins1728, through holes of a securing feature1724of the cutting guide1720. After securing pins1728securely connect the cutting guide1720to the bone, femur102, an operator may remove the pins1306(which may also be referred to as alignment pins).

FIG.17Dillustrates the cutting guide1720secured to the bone using the securing pins1728of a securing feature1724. In the illustrated embodiment, the cutting guide1720is secured to the bone such that performing a resection using the guide feature1726will resect the bone to counter for a balance status measured by the exemplary gap gauge1300.FIG.17Dillustrates that a cut made in a slot of the guide feature1726on the lateral side will remove more bone and create a femur resected surface parallel to a tibia resected surface. Similarly, a cut made in a slot of the guide feature1726on the medial side may also remove more bone and create a femur resected surface parallel to a tibia resected surface.

Those of skill in the art appreciate that the embodiments of the present disclosure serve to measure a size of a gap or opening106in a knee joint108, measure a balance status of a knee joint108, and guide surgeon in making resection adjustments based on the balance status. Those of skill in the art appreciate that various embodiments of the present disclosure can be used to adjust the balance status such that the balance status reaches a desired balance status. A desired balance status may not be balanced, but may still be a desired balance status that can meet a patient's goals. Those of skill in the art also appreciate that various embodiments of the present disclosure can be used to adjust the balance status such that the balance status reaches a balanced status. In a balanced status, opposing resected surfaces of bones of a joint may be parallel to each other.

Those of skill in the art appreciate that there are various ways the components of the present disclosure can be arranged and/or embodied that can guide a surgeon in adjusting a balance status of the knee joint108to a desired balance status, such as a balanced status. Each of these ways, manners, arrangements, and embodiments are within the scope of this present disclosure and the included claims. A few examples of embodiments that can be used include those presented in connection withFIGS.18A-18C,19,20, and21. Of course, embodiments within the scope of this disclosure and claims can made that include aspects from each of the embodiments illustrated and described in relation toFIGS.18A-18C,19,20, and21. Such embodiments can be used for example to enable more fine levels of adjustments to a balance status to achieve a desired balance status.

For example in one embodiment, an exemplary gap gauge1300can be used to determine a balance status and a cutting guide can be secured to a bone of the joint by use of a pin guide in such a way that resecting a bone using the cutting guide adjusts the balance status such that the joint has a balanced status (e.g., the resected surfaces are parallel after resecting using the cutting guide).FIGS.18A-18Cillustrate one example of such an embodiment. In this embodiment, one or more alignment features1722of a cutting guide1720cooperate with pins1306positioned by the pin guide1302to position the cutting guide1720on a bone to make a desired balance status adjustment.

FIGS.18A-18Care a front perspective view, font view, and a rear view of a cutting guide1720, according to one embodiment of the present disclosure. The cutting guide1720includes one or more alignment features1722, securing features1724, and one or more guide features1726.

The alignment feature1722, in one embodiment, can serve to position and align the cutting guide1720in relation to a bone such that performing a resection using the cutting guide1720creates a balanced status for the knee joint108and/or a desired balance status for the knee joint108. In the illustrated embodiment, the alignment feature1722may include holes placed within the cutting guide1720that are configured to receive pins, such as pins1306positioned by a pin guide1302. The holes can be positioned such that sliding the cutting guide1720on the pins1306enables a resection that counters, or adjusts, for a particular balance status (such as an imbalance status) reflected by a pin guide1302of the exemplary gap gauge1300.

For example, where the pin guide1302is connected to a superior plate118such that the pin guide1302can pivot based on a balance status of a joint108, the pins1306can be slid through corresponding holes in the cutting guide1720that will result in a compensating or adjusted resection. Referring toFIG.18B, suppose a knee joint108is +5 degrees out of balance. The balance status can be read from a balance indicator126. Said another way, the exemplary gap gauge1300may measure a nonparallel orientation of the superior plate118relative to an inferior plate120.

An operator may place pins1306through the pin guide1302that positions the pins1306in the bone with the same +5-degree balance status. If the operator wants to counter or compensate for the +5-degree balance status, the operator can slide the cutting guide1720over the pins1306such that the pins1306are within the holes of the alignment features1722with a “+5” marking. Note the corresponding holes of the alignment features1722on each side of the cutting guide1720with a “+5” marking are not parallel with each other. They are offset at an angle such that resection with the cutting guide1720will result in resected surfaces of both bones of a joint108that are parallel.

In one embodiment, a cutting guide1720can include one or more alignment features1722that may be embodied in a plurality of sets of holes. Each set of holes may include two or more holes and each of the two or more holes can be configured to accept either a first pin1306aor a second pin1306b. Each set of holes can be configured to adjust for a different angular offset. A +5-degree marked hole on one side of the cutting guide1720and a +5-degree marked hole on another side of the cutting guide1720are one example of a set of holes that may embody one or more alignment feature1722. A −5-degree marked hole on one side of the cutting guide1720and a −5-degree marked hole on another side of the cutting guide1720are one example of a set of holes that may embody one or more alignment feature1722. Of course the alignment feature1722may include a number of holes on each side posited to compensate or adjust for a number of different angular offsets of the balance status.

The guide feature1726guides a cutter to resect a bone such as a femur102in the manner needed to make a desired adjustment. For example, the guide feature1726may be used to guide a planar cutting blade, an arcuate cutting blade, a drill or mill, a burr, and/or the like. The guide feature1726may guide a reciprocating planar blade, such as that of a surgical bone saw, that forms planar cuts. In one embodiment, the guide feature1726may take the form of a first slot1730and a second slot1732, which may be positioned on each side of the cutting guide1720. In alternative embodiments, a guide feature1726may be designed to guide a different type of cutter, such as a drill, mill, or side-cutting burr. In such embodiments, the guide feature may not be a slot, but may instead be a translatable or rotatable cutter retainer that guides translation and/or rotation of the cutter relative to the bone.

FIG.18Cillustrates a rear view of one embodiment of a cutting guide1720. In certain embodiments, a rear surface of the cutting guide1720may be arcuate to more closely conform to a surface of a bone, such as a femur102. The securing feature1724may be configured to accept securing pins1728at various angles of entry, including perpendicular.

In another example embodiment, an exemplary gap gauge1300can be used to determine a balance status and a cutting guide can be secured to a bone of the joint and an adjustment made using the cutting guide in such a way that resecting a bone using the cutting guide, as adjusted, adjusts the balance status such that the joint has a desired balanced status (e.g., the resected surfaces may be parallel or non-parallel after resecting using the cutting guide and the balance status is a desired balance status). In such an embodiment, an operator can make angular adjustments on the cutting guide rather than based on how the cutting guide couples to pins1306positioned by a pin guide1302of an exemplary gap gauge1300.

FIG.19is a front view of a cutting guide1920, according to one embodiment of the present disclosure. The cutting guide1920may be similar to other embodiments described herein. The cutting guide1920may include an alignment feature1922which may include a set of holes sized to accept pins1306, one or more securing features1924, and one or more guide features1926.

The guide feature(s)1926may be embodied as a first slot1930and a second slot1932and guide motion of a cutter to resect a bone. The alignment feature(s)1922may include holes that are positioned and configured to accept a first pin1306aand a second pin1306b. The alignment feature(s)1922position the cutting guide on the bone for a resection. The securing feature(s)1924may include pins that pass through holes in the cutting guide1920and secure the cutting guide1920to the bone.

In certain embodiments, the cutting guide1920includes an adjustment feature1934. The adjustment feature1934enables an operator to adjust for different angular offsets relative to a balance status or a nonparallel orientation. The adjustment feature1934may be configured to permit adjustment to a number of angular offsets within a range, such as between 0 and +20 degrees and between 0 and −20 degrees.

In one embodiment, the adjustment feature1934is configured to rotate one or more of the guide features1926relative to the alignment feature(s)1922. For example, in one embodiment, the adjustment feature1934includes a knob1936that can be turned relative to the cutting guide1920to change an orientation of one or more guide features1926and set a different angular offset for guide features1926relative to the balance status and/or the nonparallel orientation.

The adjustment feature1934may include a face1938that includes one or more markings1940indicating different angular offsets. An operator can rotate the knob1936compensate, or counter, a balance status or nonparallel orientation. As the knob1936rotates the guide features1926may move in the direction of arrow A.

In another example embodiment, an exemplary gap gauge1300can be used to determine a balance status and a cutting guide can be secured to a bone of the joint and an adjustment made using a pin guide in such a way that resecting a bone using the cutting guide, as positioned by the adjusted pin guide, adjusts the balance status such that the joint has a desired balanced status (e.g., the resected surfaces may be parallel or non-parallel after resecting using the cutting guide and the balance status is a desired balance status). In such an embodiment, an operator can make angular adjustments on the pin guide rather than based on how the cutting guide couples to pins1306positioned by a pin guide1302or adjustments made on the cutting guide.

FIG.20is a front view of a pin guide2002, according to one embodiment of the present disclosure. The pin guide2002may be connected to and/or removable coupled to a gap gauge such as exemplary gap gauge1300. The pin guide2002may generally include a base1310, arm1312with pin holes1304(e.g. first pin hole1304aand/or second pin hole1304b), and mast1314similar in structure, performance, and/or operation to like numbered components in other embodiments previously described. The first pin hole1304aand second pin hole1304bcan be configured to guide insertion of a second pin1306bparallel to a first pin1306ainto a bone.

In the illustrated embodiment, the pin guide2002may include an adjustment feature2004. The adjustment feature2004may include a face2006, a needle2008, and a set of markings2010. The adjustment feature2004may also include a knob2012. The adjustment feature2004enables a user to rotate the knob2012to select a particular number of degrees away from balanced for a subsequent resection. This selected number of degrees may be opposite the number of degrees indicated on a balance indicator126of the exemplary gap gauge1300. For example, if the balance indicator126indicates −5 degrees a user may rotate the knob2012to point to +5 degrees such that the −5 degrees of imbalance is countered or compensated for.

Rotating the knob2012may cause the arm1312to rotate such that the first pin hole1304aand second pin hole1304brotate together to counter different angular offsets of the balance status. The knob2012, or another structure may tighten the adjustment feature2004such that arm1312maintains the orientation after the knob2012is rotated to a desired setting, angular rotation. Once the pin guide2002is configured to compensate for a balance status, an operator may insert the first pin1306aand second pin1306bthrough corresponding first pin hole1304aand second pin hole1304b.

Next, as described above, the exemplary gap gauge1300may be slid off of the pins1306and a cutting guide may be slide over the pins1306and secured to a bone. In such an embodiment, the cutting guide may not include angular adjustment features and may instead include securing feature(s) and one or more guide features. In this manner, the pin guide2002may provide an angular adjustment for a resection.

In another example embodiment, an exemplary gap gauge1300can be used to determine a balance status and a cutting guide can be secured to a bone of the joint by use of a pin guide coupled to the exemplary gap gauge1300in such a way that resecting a bone using the cutting guide adjusts the balance status such that the joint has a balanced status (e.g., the resected surfaces are parallel after resecting using the cutting guide). In such an embodiment, an operator can secure a cutting guide a bone by use of a pin guide coupled to the exemplary gap gauge1300in such a way that using a cutting guide (that does not include adjustment features) adjusts the balance status such that the joint has a balanced status. Angular adjustments using the pin guide or cutting guide are not needed.

FIG.21is a side perspective view of a pin guide2102, according to one embodiment of the present disclosure within an embodiment of an exemplary gap gauge2100. In one embodiment, the exemplary gap gauge2100may generally include a first plate and a second plate. In the illustrated embodiment, the first plate may be an inferior plate120and the second plate may be a superior plate118. The superior plate118may include a pivot plate148and a support plate150. The first plate120can be positioned in contact with a first bone, such as a tibia104and the second plate118can be positioned in contact with a second bone, such as a femur102. In one embodiment, the first plate and the second plate are sized for insertion between a first bone that is a tibia and a second bone that is a femur. The superior plate118, inferior plate120, pivot plate148, and support plate150may be similar in structure, performance, and/or operation to like numbered components in other embodiments previously described.

The exemplary gap gauge2100may also generally include a separator122, a separation indicator124, a balance indicator126, a handle134, a superior body136, and an inferior body138similar in structure, performance, and/or operation to like numbered components in other embodiments previously described.

In one embodiment, the exemplary gap gauge2100includes a pin guide2102similar in structure, performance, and/or operation to like numbered components in the embodiment illustrated inFIG.14A, with the following exceptions. In the illustrated embodiment, the pin guide2102may include a mast2114that is long enough to connect or couple the pin guide2102to the inferior plate120, rather than a superior plate118, pivot plate148, or support plate150. In another embodiment, the pin guide2102may include a base configured to connect or couple the pin guide2102to the support plate150. The methods or operation and use described herein can be used with the exemplary gap gauge2100to complete an arthroplasty procedure.

In the illustrated embodiment, the pin guide2102extends in the direction of a second bone, such as the femur102. The pin guide2102guides insertion of a first pin1306aand a second pin1306binto the second bone, the femur102. The pin guide2102aligns the first pin1306aand second pin1306bwith each other at an angle relative to the second plate (superior plate118) that counters a balance status between the first plate (inferior plate120) and the second plate (superior plate118). The pin guide2102may be couplable to the exemplary gap gauge2100by way of a set screw1320similar to that described above.

When the exemplary gap gauge2100is in use in a knee joint108, the inferior plate120contacts the tibia104and the superior plate118contacts the femur102. An operator can then review and adjust for a gap and a balance status. The balance status can be measured, at least in part, because the pivot plate148is configured to pivot relative to the support plate150and/or inferior plate120. Because the pin guide2102connects, or is connectable, to a non-pivoting plate (such as the inferior plate120or support plate150) and the arm1312is perpendicular to the mast2114and the mast2114is perpendicular to the non-pivoting plate, pins1306inserted into parallel pin holes1304of the pin guide2102are parallel to the non-pivoting plate. Consequently, a cutting guide guided by the pins1306and secured to the femur102and having a guide feature parallel to the two aligned pins1306will guide a resection that counters the balance status between the first plate (inferior plate120) and the second plate (superior plate118). In this manner, no further angular adjustment may be needed from the pin guide or the cutting guide.

FIG.22illustrates a flowchart for a method2200for measuring and adjusting imbalance for an arthroplasty procedure on a femur and a tibia of a patient, according to one embodiment of the present disclosure. In general, the method1200may include the use of gap gauge that includes both a balance indicator126and a pin guide. In certain embodiments, the method1200may also include a cutting guide as part of an assembly.

The method2200may begin with a step2210in which a first plate (e.g., inferior plate120) and a second plate (e.g., superior plate118) of a gap gauge may be inserted between a femur and a tibia. In certain embodiments, the gap gauge may be positioned such that a pivot axis of a hinge may be aligned with an anterior-posterior axis of a patient.

Once the gap gauge is positioned, the method2200may proceed to step2220in which the first plate and second plate are actuated apart such that the first plate contacts a resected surface of the femur and the second plate contacts a resected surface of the tibia.

Once the first plate and second plate have been actuated apart, the method2200may proceed to step2230in which a balance indicator of the gap gauge is read to obtain a balance status between the femur and the tibia.

A surgeon may use the balance status to determine whether to do further resection of the femur102and/or tibia104, and/or where to position a cutting guide for the resection.

Once a balance status has been read, the method2200may proceed to step2240in which a first pin is inserted through a pin guide of the gap gauge. The method2200may then proceed to step2250in which the first pin is secured to one of the femur and the tibia. Next the method2200may then proceed to step2260in which a cutting guide is coupled to the one of the femur and the tibia using the first pin. Once the cutting guide is coupled to the one of the femur and the tibia, the method2200may then proceed to step2270in which the cutting guide is used to guide resection of one of the femur and the tibia to counter a nonparallel orientation of the first plate relative to the second plate.

After performing the resection, the method2200may end with the two bones resected to a desired balance status.

Any methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.

Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.

Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, Figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following this Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims.

Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements recited in means-plus-function format are intended to be construed in accordance with 35 U.S.C. § 112 Para. 6. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles set forth herein.

While specific embodiments and applications of the present disclosure have been illustrated and described, it is to be understood that the scope of this disclosure is not limited to the precise configuration and components disclosed herein. Various modifications, changes, and variations which will be apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems of the present disclosure set forth herein without departing from it spirit and scope.