WO2023003929A1

WO2023003929A1 - Arthroplasty knee implant devices

Info

Publication number: WO2023003929A1
Application number: PCT/US2022/037669
Authority: WO
Inventors: Christopher R. Cyko; Maureen RICKEN; Jason S. Jordan; Michael Dean Hughes
Original assignee: Smith & Nephew, Inc.; Smith & Nephew Orthopaedics Ag; Smith & Nephew Asia Pacific Pte. Limited
Priority date: 2021-07-23
Filing date: 2022-07-20
Publication date: 2023-01-26

Abstract

An anchored implant (204) device including a baseplate (210) and a separate anchor (324). The baseplate and the anchor are individual components that are configured to be separately installed in or on the bone of the patient to provide fixation of the baseplate to a portion of the bone, such as a (resected) tibia. The anchored implant device may be configured with an adjustment feature to allow the baseplate to move in a superior-inferior direction to maintain a flush mounting of the baseplate on a prepared bone surface in an abnormal condition, such as an anchor being at an inadequate depth within the bone. In some embodiments, a contoured implant device (604) may include a device with contoured features configured to engage corresponding features of a prepared portion of a prepared knee joint.

Description

ARTHROPLASTY KNEE IMPLANT DEVICES

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63/225,093, filed July 23, 2021 and titled “Arthroplasty Knee Implant Devices” and U.S. Provisional Patent Application Serial No. 63/337,834, filed May 3, 2022 and titled “Arthroplasty Knee Implant Devices,” the entire contents of both applications are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

[0002] The present disclosure is directed to orthopedic implants, and more specifically to a total knee arthroplasty knee implant system or a unicondylar knee implant system.

BACKGROUND

[0003] Partial (unicondylar) knee arthroplasty, also referred to as unicompartmental knee replacement or partial knee replacement, is a procedure in which one of either the medial or lateral compartments of the distal femur and/or the proximal tibia can be replaced with an implant device. Typically, implant devices used for partial knee arthroplasty are designed to at least attempt to anatomically fit the proximal tibia anatomy of the patient.

[0004] Component loosening is a primary failure mechanism in unicompartmental knee arthroplasty. Traditionally, a patient’s tibia would be resectioned using a set of orthopedic saws to a flat surface on which a tibia component could then be implanted. The component likewise would have a flat (or substantially flat) bone-facing distal surface that would mirror the resectioned tibia surface. This component would then be either cemented in place or feature some type of bone ingrowth (porous) surface to provide fixation to the resectioned tibia.

[0005] The use of bone cement to attach a prosthetic component onto a prepared bone provides immediate fixation but has various disadvantages that appear over time. For example, physical loads are repeatedly applied to the implant over its life. If bone cement is used to secure a unicompartmental knee prosthesis, the bone cement may fatigue and fracture under the repeated loading. Such fatigue may lead to degradation of the bone cement integrity, causing the component to become loose, thereby necessitating replacement.

[0006] Conventional cementless component fixation typically involves press fit features permanently attached to an implant or augmented with a screw or fixation device that would violate the outer bony cortex. In such systems, designs with screws would typically require additional bone to be removed to provide an interface between the implant and screw. In addition, designs that violate the anterior cortex may weaken the remaining subchondral bone and lead to early failures due to overstress of the bony structure.

[0007] It is with this in mind that the present disclosure is provided. SUMMARY

[0008] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

[0009] Disclosed herein are improved arthroplasty implant devices. In some embodiments, an arthroplasty implant device may be in the form of a fixation element implant device that includes a baseplate and a separate fixation device. The baseplate and the fixation device may be individual, separable, or otherwise non-integral components of the fixation element implant device. In various embodiments, the fixation device may be or may include an anchor, fastener, or other type of element capable of engaging (e.g., forming a friction or press-fit with) a portion of a bone. Although anchors (or the terms “anchor” or “anchored implant devices”) are used in some examples, embodiments are not so limited, as any type of fixation element capable of operating with the described embodiments is contemplated in the present disclosure.

[0010] In some embodiments, an arthroplasty implant device may be in the form of an anchored implant device that includes a baseplate and a separate anchor. The baseplate and the anchor may be individual components that are configured to be separately installed in or on the bone of the patient. The anchor may be configured to provide fixation of the baseplate to a portion of the bone, such as a (resected) tibia. In various embodiments, the anchor may be configured to provide fixation of the baseplate without requiring violation of the bony cortex of the tibia. An anchored implant may operate to provide improved fixation over conventional systems, while requiring removal of less bone stock, avoiding violation of the bony cortex, and providing increased residual bony strength after implantation.

[0011] In some embodiments, an arthroplasty implant device may be in the form of a contoured implant device. In some embodiments, a contoured implant device may include a modular unicondylar tibia implant with a three-dimensionally (3D) contoured distal bone-facing surface that may be primarily concave, primarily convex, or a combination thereof. In addition, surfaces of the contoured implant device, such as a distal bone-facing surface, may include protrusions, ridges, bumps, and/or other projections configured to enhance fixation of the contoured implant device to a patient.

[0012] Conventional arthroplasty methods use an orthopedic saw capable of creating flat or substantially flat cuts or resections in bone for receiving an arthroplasty implant device, such as a tibial plate. However, surgical systems, such as computer-assisted or robotic surgical systems, may use burrs, drills, or other cutting tools to make non-flat or contoured resections of bone. For example, a surgical system may include a cutting instrument (e.g., a robotic spherical burr) that is orientable in all six degrees of freedom and capable of producing a freeform or otherwise contoured 3D resection surface.

[0013] Accordingly, some embodiments may include contoured implant devices having surfaces that correspond to contoured 3D resection surfaces of patient bone. Contoured implant devices according to some embodiments may be configured to target improved fixation over a conventional flat preparation and/or to preserve strength of bone by targeting bone removal where strength of retained bone is maximized and stress concentrations minimized.

[0014] In some embodiments, an anchored implant device may include a baseplate and an anchor, the baseplate and the anchor may be formed as separate components of the anchored implant device. The baseplate may include a first side configured to be installed on a prepared surface of a knee joint and a second side that is opposite the first side. The anchor may include a top portion and a leading edge or surface, the leading surface may be configured to be installed within a prepared interior space of the knee joint. The baseplate may include a slot having a structure configured to engage the top portion of the anchor on the second side while the leading surface is installed within the prepared interior space. The leading surface may engage surfaces of the prepared interior space to implement a press fit between the anchor and the prepared interior space, thereby mounting the baseplate on the prepared surface of the knee joint.

[0015] In some embodiments, a method for implanting an anchored implant device in a patient may include preparing a prepared surface and a prepared interior space of a knee joint, installing a baseplate of the anchored implant device on the prepared surface, installing a leading surface of an anchor of the anchored implant device through a slot in the baseplate and into the prepared interior space such that a top surface of the anchor engages or mates with the slot and the leading surface forms a press fit with the prepared interior space, thereby affixing the baseplate to the prepared surface. [0016] In some embodiments, a method for implanting an anchored implant device in a patient may include preparing a prepared surface and a prepared interior space of a knee joint, installing a leading surface of an anchor of the anchored implant device into the prepared interior space, placing the baseplate over the anchor such that a top portion of the anchor extends through or into the slot, moving the baseplate over the anchor (for example, in an anterior-posterior direction or vice versa, depending on the configuration of the anchor and the baseplate) until the top portion engages the slot to mount the baseplate on or about the knee joint.

[0017] In some embodiments of the anchored implant device, the prepared surface of the knee joint may include a proximal surface of a tibia. In some embodiments of the anchored implant device, the prepared surface of the knee joint may include a proximal surface of a tibia, and the first side may include a distal side of the baseplate and the second side may include a proximal side of the baseplate. In some embodiments of the anchored implant device, the prepared surface of the knee joint may include a surface of a distal portion of a femur.

[0018] In some embodiments of the anchored implant device, the anchored implant device may be an implant component of an arthroplasty implant system. In some embodiments of the anchored implant device, the anchored implant device may be an implant component of a unicompartmental knee replacement or partial knee replacement system. In some embodiments of the anchored implant device, the anchored implant device may be an implant component of a total knee arthroplasty (TKA) system. In some embodiments of the anchored implant device, the anchored implant device may be a tibial component of an arthroplasty implant system. In some embodiments of the anchored implant device, the anchored implant device may be a femoral component of an arthroplasty implant system.

[0019] In some embodiments of the anchored implant device, the anchored implant device may be a tibial component configured to be operably mounted or otherwise secured to a prepared or resected proximal portion of a tibia.

[0020] In some embodiments of the anchored implant device, the anchor may be configured to be installed by passing the leading surface through the slot from the first side to the second side. For example, the anchor may be fitted through the slot, for instance, in an inferior- superior direction, such that the anchor may compress and lock the baseplate to the prepared proximal tibia. In another example, the anchor may be fitted through the slot to allow for an adjustable mounting or securing of the baseplate on or about the prepared proximal tibia.

[0021] In various embodiments of the anchored implant device, the anchor may be configured to be installed within the prepared interior space to form a press fit prior to placement of the baseplate on the knee joint, and the baseplate may be placed over the anchor such that the top portion of the anchor extends through or into the slot, the baseplate may be moved over the anchor (for example, in an anterior-posterior direction or vice versa, depending on the configuration of the anchor and the baseplate) until the top portion engages the slot, thereby mounting the baseplate to the knee joint. [0022] In some embodiments of the anchored implant device, the leading surface may be curved or substantially curved. In some embodiments of the anchored implant device, the top portion may include one or more protrusions or ridges configured to engage at least one corresponding structure of the slot to facilitate engagement between the top portion and the second side of the baseplate. In some embodiments of the anchored implant device, the leading surface may include at least one opening to facilitate bone ingrowth with the anchor.

[0023] In some embodiments of the anchored implant device, the baseplate may include at least one secondary fixation element extending from the first side and into the prepared interior space. In some embodiments of the anchored implant device, the at least one secondary fixation element may include at least one of a keel, a fin, a projection, a groove, or a peg. In various embodiments of an anchored implant device, the baseplate and secondary fixation devices may be formed from an integral piece. In other embodiments of an anchored implant device, the baseplate and secondary fixation devices may be formed separately, and the secondary fixation devices may be affixed to the baseplate.

[0024] In some embodiments of the anchored implant device, the anchor may be configured to be installed through the slot and into the prepared interior space. In some embodiments of the anchored implant device, the leading surface of the anchor may be configured to engage at least a portion of the at least one secondary fixation element. In some embodiments of the anchored implant device, the at least one secondary fixation element may include a keel and the leading surface of the anchor may be configured to envelope at least a portion of the keel. In some embodiments of the anchored implant device, the at least one secondary fixation element may include a keel and the leading surface of the anchor may include a slot configured to receive at least a portion of the keel. In some embodiments of the anchored implant device, the leading surface may be configured to form a press fit with the at least one secondary fixation element.

[0025] In some embodiments, the anchored implant device may be configured with an adjustment feature to allow the baseplate to move in a superior-inferior (or substantially superior-inferior) direction to maintain a flush mounting of the baseplate on a prepared bone surface in an abnormal condition, such as an anchor being at an inadequate depth within the bone. In general, movement in a superior-inferior direction is not restricted to a rigid superior-inferior axis; rather, a superior- inferior direction may include a substantially superior-inferior direction or axis.

[0026] For example, in various embodiments, an anchored implant device may be configured to facilitate adjustable mounting of a baseplate about a fixation element (e.g., an anchor) to allow for flush mounting of a baseplate on a prepared surface of bone, including when there is abnormal installation or configuration (e.g., post-installation movement) of a fixation element (e.g., the fixation element sticks out further from the bone than expected).

[0027] In some embodiments, a contoured implant device may include a baseplate having a first side configured to be installed on a prepared surface of a knee joint. The first side may have at least one contoured feature. In some embodiments, the at least one contoured feature may include a concave surface portion, a convex surface portion, a concave and convex portion, an angled surface portion, a curved surface portion, a wavy surface portion, projections arranged on a surface portion, recesses or cavities arranged on a surface portion, or combinations thereof. In various embodiments, the at least one contoured feature may correspond with a contoured feature of the prepared surface of the knee joint.

[0028] In some embodiments of the contoured implant device, the first side may include at least one secondary fixation element. In some embodiments, the at least one secondary fixation element may include a keel, a fin, an anchor, a peg, a ridge, a slot, a recess, a bump, a projection, a groove, or combinations thereof. In various embodiments, the at least one secondary fixation element may include fixation elements. For example, a peg may include a groove or slot.

[0029] In various embodiments, the contoured implant device may include at least one contoured feature on at least one of an anterior surface, a posterior surface, a medial surface, or a lateral surface.

[0030] In some embodiments, a method for implanting a contoured implant device in a patient may include preparing a prepared surface of a knee joint, the prepared surface having at least one bone contoured surface. Installing a first side of a baseplate of the contoured implant device on the prepared surface. The first side having at least one contoured feature that corresponds with the at least one bone contoured surface to facilitate engagement or affixation of the contoured implant device with the prepared surface.

[0031] In some embodiments, the prepared surface may be prepared using a computer- assisted or robotic surgery system using a non-flat or non-planar cutting tool, including, without limitation, cylindrical, spherical, or other shaped burrs that may be guided in free 3D space. In various embodiments, the prepared surface may include bone contoured features configured to receive or otherwise engage the secondary fixation structures of the contoured implant device.

[0032] In some embodiments of the contoured implant device, the prepared surface of the knee joint may include a proximal surface of a tibia. In some embodiments of the contoured implant device, the prepared surface of the knee joint may include a proximal surface of a tibia, and the first side may include a distal side of the baseplate. In some embodiments of the contoured implant device, the prepared surface of the knee joint may include a surface of a distal portion of a femur.

[0033] In some embodiments of the contoured implant device, the contoured implant device may be an implant component of an arthroplasty implant system. In some embodiments of the contoured implant device, the contoured implant device may be an implant component of a unicompartmental knee replacement or partial knee replacement system. In some embodiments of the contoured implant device, the anchored implant device may be an implant component of a total knee arthroplasty (TKA) system. In some embodiments of the contoured implant device, the contoured implant device may be a tibial component of an arthroplasty implant system. In some embodiments of the contoured implant device, the contoured implant device may be a femoral component of an arthroplasty implant system.

[0034] In some embodiments of the contoured implant device, the contoured implant device may be a tibial component configured to be operably mounted or otherwise secured to a prepared or resected proximal portion of a tibia.

[0035] In some embodiments of the contoured implant device, the bone contoured feature may be a concave surface and the contoured feature of the contoured implant device may be a corresponding convex surface of the first side. In some embodiments of the contoured implant device, the bone contoured feature may be a convex surface and the contoured feature of the contoured implant device may be a corresponding concave surface of the first side. In some embodiments of the contoured implant device, the bone contoured feature may be a surface with a mixture of concave and convex elements and the contoured feature of the contoured implant device may be a surface on the first side with a mixture of concave and convex elements configured to be arranged within corresponding structures of the prepared surface. In some embodiments of the contoured implant device, the contoured feature of the contoured implant device may be a secondary fixation element and the bone contoured feature may be a structure configured to receive or otherwise engage the secondary fixation element.

[0036] In some embodiments, an anchored tibial implant device may include a baseplate configured to be arranged on a prepared surface of a proximal end of a tibia, the baseplate may include at least one slot and at least one baseplate engagement structure, and an anchor, separate from the baseplate, that may be configured to be arranged within the slot and within at least a portion of the proximal end of the tibia at least partially below the prepared surface, the anchor may include at least one edge configured to engage (e.g., form a press-fit with) bone within the tibia, and at least one anchor engagement structure configured to engage the at least one baseplate engagement structure to hold the baseplate on the prepared surface of the tibia, wherein the baseplate engagement structure is configured to facilitate adjustable mounting of the baseplate about the anchor on the prepared surface.

[0037] In various embodiments of the anchored tibial implant device, the adjustable mounting allows for movement of the baseplate in a superior-inferior direction. In some embodiments of the anchored tibial implant device, the adjustable mounting allows for movement of the baseplate to facilitate flush mounting of the baseplate against the prepared surface in an abnormal configuration of anchor. In exemplary embodiments of the anchored tibial implant device, the baseplate engagement structure may be configured to facilitate movement of the baseplate in an inferior direction toward the prepared surface to facilitate flush mounting of the baseplate against the prepared surface in an abnormal configuration of anchor.

[0038] In various embodiments of the anchored tibial implant device, the at least one baseplate engagement structure may include at least one ridge. [0039] In some embodiments of the anchored tibial implant device, the at least one anchor engagement structure may include at least one protrusion configured to be seated within the at least one ridge.

[0040] In exemplary embodiments of the anchored tibial implant device, the at least one baseplate engagement structure may include a plurality of ridges, and the at least one anchor engagement structure may include a plurality of protrusions, each of the plurality of protrusions may be configured to be seated within one of the plurality of ridges.

[0041] In some embodiments of the anchored tibial implant device, the anchor may be configured to be installed through the slot of the baseplate arranged on the prepared surface of the tibia.

[0042] In various embodiments of the anchored tibial implant device, the at least one anchor engagement structure may include at least one flange configured to be seated on the at least one ridge.

[0043] In various embodiments of the anchored tibial implant device, the baseplate may be configured to be installed over the anchor arranged within the tibia.

[0044] In exemplary embodiments of the anchored tibial implant device, the baseplate may include a keel configured to be arranged within at least a portion of the proximal end of the tibia at least partially below the prepared surface, and the at least one anchor engagement structure may include a channel configured to fixedly engage an edge of the keel. [0045] In some embodiments of the anchored tibial implant device, the baseplate engagement structure may be configured to facilitate adjustable mounting of the baseplate about the anchor on the prepared surface.

[0046] In various embodiments of the anchored tibial implant device, the baseplate engagement structure may be configured to facilitate movement of baseplate in an inferior direction toward the prepared surface to allow flush mounting of the baseplate against the prepared surface in an abnormal installation of anchor.

[0047] In some embodiments of the anchored tibial implant device, the anchor may be configured to provide cementless fixation of the anchored tibial implant device.

[0048] In some embodiments, a contoured tibial implant device may include a three- dimensionally (3D) contoured first surface, the first surface configured to be arranged on a prepared surface of a tibia, and a 3D contoured second surface, the second surface configured to engage a femur or a femur component of a knee joint.

[0049] In various embodiments of the contoured tibial implant device, the 3D contoured first surface may be shaped to correspond to a corresponding 3D resectioned surface of the prepared surface prepared by a computer-assisted surgical system.

[0050] In some embodiments of the contoured tibial implant device, the contoured tibial implant device may include at least one contoured feature on one of a medial surface or a lateral surface. [0051] In various embodiments of the contoured tibial implant device, the first surface may include a mixture of convex projections and concave recesses.

[0052] Embodiments of the present disclosure provide numerous advantages. For example, by incorporating one or more features of the present disclosure, surgeons are provided with increased options for securing an implant device for an arthroplasty procedure. In addition, and/or alternatively, by incorporating one or more features of the present disclosure, the implant device is arranged and configured to facilitate easier insertion with reduced or even eliminated violation of the bony cortex. In addition, and/or alternatively, by incorporating one or more features of the present disclosure, the implant device is arranged and configured to facilitate better positioning of the implant device, and individual components thereof, against the patient’s bone. Furthermore, by incorporating one or more features of the present disclosure, an anchored implant may operate to provide improved fixation over conventional systems, while requiring removal of less bone stock to be removed, avoiding violation of the bony cortex, and providing increased residual bony strength after implantation. In addition, or in the alternative, a baseplate may be configured to engage an anchor such that the anchor may hold the baseplate in position on or about a prepared bone surface, while allowing for translation in a superior-inferior direction. Accordingly, an anchored implant device according to some embodiments may allow for adjustable mounting in which a baseplate may move toward a prepared bone surface in an abnormal installation or configuration (e.g., the anchor is not installed to or moves from a required depth) to allow the baseplate to be flush or substantially flush with the prepared bone surface. Moreover, by incorporating one or more features of the present disclosure, a contoured implant device according to some embodiments may be configured to target improved fixation over a conventional flat preparation and/or to preserve strength of bone by targeting bone removal where the strength of retained bone is maximized and stress concentrations minimized.

[0053] Further features and advantages of at least some of the embodiments of the described technology, as well as the structure and operation of various embodiments of the described technology, are described in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] By way of example, various embodiments of the disclosed device will now be described, with reference to the accompanying drawings, in which:

[0055] FIG. 1 is a diagram illustrating an environment for operating a system for planning and performing an arthroplasty surgery in accordance with one or more features of the present disclosure;

[0056] FIG. 2A illustrates a side perspective view of an exemplary implant device that can be utilized for unicompartmental knee replacement in accordance with one or more features of the present disclosure;

[0057] FIG. 2B illustrates a side view of the exemplary implant device depicted in FIG. 2A implanted in a knee joint in accordance with one or more features of the present disclosure; [0058] FIGS. 3A-3E illustrate various views of a first embodiment of an anchored implant device in accordance with one or more features of the present disclosure;

[0059] FIGS. 4A-4E illustrate various views of a second embodiment of an anchored implant device in accordance with one or more features of the present disclosure;

[0060] FIGS. 5A-5C illustrate various views of a third embodiment of an anchored implant device in accordance with one or more features of the present disclosure;

[0061] FIGS. 6A-6F illustrate various views of a first embodiment of a contoured implant device in accordance with one or more features of the present disclosure;

[0062] FIGS. 7A-7F illustrate various views of a second embodiment of a contoured implant device in accordance with one or more features of the present disclosure;

[0063] FIGS. 8A-8F illustrate various views of a third embodiment of a contoured implant device in accordance with one or more features of the present disclosure;

[0064] FIGS. 9A-9F illustrate various views of a fourth embodiment of a contoured implant device in accordance with one or more features of the present disclosure;

[0065] FIGS. 10A and 10B illustrate various views of a fifth embodiment of a contoured implant device in accordance with one or more features of the present disclosure;

[0066] FIG. 11 illustrates a prior-art fixation element implant device; [0067] FIGS. 12A and 12B illustrate adjustable mounting of an anchored implant device in accordance with one or more features of the present disclosure; and

[0068] FIGS. 13A-13D illustrate various views of a fourth embodiment of an anchored implant device in accordance with one or more features of the present disclosure.

[0069] It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of the disclosed methods and devices, or which render other details difficult to perceive may have been omitted. It should be further understood that this disclosure is not limited to the particular embodiments illustrated herein. In the drawings, like numbers refer to like elements throughout unless otherwise noted.

DETAILED DESCRIPTION

[0070] Various features of arthroplasty implant devices will now be described more fully hereinafter with reference to the accompanying drawings, in which one or more features of the implant device will be shown and described. It should be appreciated that the various features or the like described hereinafter may be used independently of, or in combination, with each other. It will be appreciated that an implant system, device, plate, component, and/or portion thereof as disclosed herein may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain features of the implant device to those skilled in the art. [0071] Disclosed herein are implant components including one or more features for enabling, inter alia, increased flexibility, conformity, and fixation for coupling implant devices to bone, particularly resected surfaces of a tibia or femur to implement an arthroplasty procedure.

[0072] Component loosening is a primary failure mechanism in knee arthroplasty, including unicompartmental knee arthroplasty. Fixation by design is one factor in addressing this failure mechanism that incorporates implant geometry, materials, methods, and bony preparation. Traditionally, cementless knee implant components would be affixed by press fit features permanently attached to an implant or augmented via a screw or other fixation device that would violate the outer bony cortex. In such conventional systems, designs with screws would typically require additional bone to be removed to provide an interface between the implant and the screw. In addition, such designs typically violate the anterior cortex, which may weaken the remaining subchondral bone and lead to early failures due to overstress of the bony structure.

[0073] Conventional arthroplasty surgical techniques involve resection of the tibia using a set of orthopedic saws to a flat surface on which a tibia component was then implanted. The component likewise would have a flat, or nearly flat, bone-facing distal surface that would mirror the resectioned tibia surface. This component would then be either cemented in place or feature some type of bone ingrowth surface to provide fixation to the resectioned tibia. [0074] In cases where this was believed to be inadequate to counteract in-vivo forces contributing to component loosening, additional, secondary design fixation features would be included. These features would typically include one or more pegs/lugs and/or one or more keels to increase the fixation area and provide geometric resistance to loosening.

[0075] As bony preparation technology has improved, the simple orthopedic saw is no longer the sole means for preparing a bony geometry by which a tibia component could then be implanted. For example, computer-assisted or robotic systems provide for cylindrical, spherical, and other shaped burrs that may be guided in free three- dimensional (3D) space. However, conventional component design and techniques have continued to feature flat primary preparation and implants with flat bone-facing geometries that mimic this flat preparation.

[0076] Accordingly, some embodiments may provide an anchored implant device that may be configured as a modular implant with either a straight or curved anchor to enhance fixation, in which the anchor may be implanted in such a way that the bony cortex is not violated. In other embodiments, a contoured implant device may include contoured (or non-flat) surfaces with 3D structures, such as convex and/or concave surfaces and/or protrusions, to correspond with contoured (non-flat) resected bone surfaces.

[0077] As will be described herein, an implant device may have various shapes, sizes, and/or configurations of other physical properties. It should be appreciated that the implant device may be provided in any suitable shape and/or configuration, which, as will be appreciated by one of ordinary skill in the art, may be dependent on the location and type of patient bone being fixed. For example, an implant device may include various bone conforming segments configured to correspond with different anatomical features. In addition, the implant device may be arranged and configured to span, contact, be affixed to, and/or the like various portions of a human knee, including without limitation, the tibia and/or femur.

[0078] As will be described herein, the implant device may include any now known or hereafter developed additional features. The implant device may be manufactured from any suitable material now known or hereafter developed, including, for example, metals, polymers, plastics, ceramics, resorbable, non-resorbable, composite materials, etc. Suitable materials may include, for example, titanium, stainless steel, cobalt chrome, polyetheretherketone (PEEK), polyethylene, ultra-high molecular weight polyethylene (UHMWPE), resorbable polylactic acid (PLA), polyglycolic acid (PGA), combinations or alloys of such materials or any other appropriate material that has sufficient strength to be secured to and hold bone, while also having sufficient biocompatibility to be implanted into a patient’s body.

[0079] Although unicompartmental implant devices and tibial devices, in particular, are used in some examples in the present disclosure, embodiments are not so limited. Therefore, it should be appreciated that the present disclosure should not be limited to any particular configuration of implant device and/or insertion procedure unless specifically claimed. In addition, while the present disclosure will be described and shown as being directed to a unicompartmental tibial implant component, it should be appreciated that features of the present disclosure have applicability and may be used in connection with other implant devices such as, a femur component, a TKA implant system, and/or the like.

[0080] FIG. 1 is an illustration of a system 100 for performing an arthroplasty surgical procedure using a robotic system. In some embodiments, system 100 may be or may include an image-free (for instance, CT-less) system. In other embodiments, system 100 may be or may include an image-based system based on diagnostic image data. In various embodiments, system 100 may operate using a combination of image-free and image-based processes. Embodiments are not limited in this context.

[0081] System 100 may include a surgical cutting tool 150 with an associated optical tracking frame 155 (also referred to as tracking array 155), graphical user interface 130, an optical tracking system 140, and patient tracking frames 120 (also referred to as tracking arrays 120). The illustration also includes an incision 110 through which, for example, a knee revision surgery may be performed. In an example, the illustrated robotic surgical system 100 depicts a hand-held computer-controlled surgical robotic system, for instance, the same or similar to the Navio® Surgical System from Blue Belt Technologies of Plymouth, Minnesota. System 100 may use an optical tracking system 140, or other type of tracking system, coupled to a robotic controller to track and control a hand-held surgical instrument. For example, optical tracking system 140 tracks tracking array 155 coupled to surgical tool 150 and tracking arrays 120 coupled to the patient to track locations of the instrument relative to the target bone (e.g., femur and/or tibia for knee procedures).

[0082] In some embodiments, surgical cutting tool 150 may be configured to implement contoured, 3D, concave, convex, slanted, angled, beveled, ribbed, ridged, grooved, or otherwise non-flat or non-planar cuts or resections to patient bone, including surfaces with cavities, recesses, channels, slots, and/or the like.

[0083] FIG. 2A illustrates a side perspective view of an exemplary implant device that can be utilized for unicompartmental knee replacement in accordance with one or more features of the present disclosure. As shown in FIG. 2A, implant 200 may include a femoral component 202 and a tibial component 204. Tibial component 204 may include an anterior side 232 and a posterior side 230. An upper portion of tibial component 204 may include a tibial articular surface 208 that contacts or articulates against a femoral articular surface 206 of femoral component 202 in a manner that at least assists in providing a functioning knee joint. In exemplary embodiments, tibial component 204 may include a tibial baseplate 210 and an insert 212 configured to provide tibial articular surface 206.

[0084] In some embodiments, tibial baseplate 210 and insert 212 may be separate components that are constructed from different materials. Further, insert 212 may include one or more trial inserts that is/are used at least temporarily during the implantation procedure or surgery, as well as inserts that are selected for final implantation with implant 200.

[0085] FIG. 2B illustrates a side view of the exemplary implant device depicted in FIG. 2 A implanted in a knee joint in accordance with one or more features of the present disclosure. As shown in FIG. 2B, femoral component 202 may be configured to be operably mounted or otherwise secured to distal femur portion 216 of femur 214, while tibial component 204 may be configured to be operably mounted or otherwise secured to proximal tibia portion 220 of tibia 218. In various embodiments, tibial baseplate 210 may include one or more fixation members 224 that can at least assist in tibial baseplate 210 being secured to tibia 218.

[0086] A variety of types of fixation members 224, or combinations of fixation members 224, may be utilized for securing tibial baseplate 210 to tibia portion 220. For example, fixation member(s) 224 may include, or be configured for use, as part of a cementless fixation system according to various embodiments described in the present disclosure. Such fixation members 224 include, but are not limited to, one or more screws, pegs, posts, fins, rails, cavities, anchors, protrusions, concave surfaces, convex surfaces, grooves, projections, bumps, and/or a combination thereof (see, for example, FIGS. 3A- 10B). At least certain types of fixation members 224 can be configured to provide features or a geometry to tibia baseplate 210 that may provide for rigid, cementless fixation to tibia 218. [0087] FIGS. 3A-3E illustrate various views of a first embodiment of an anchored implant device in accordance with one or more features of the present disclosure. As shown in FIG. 3A, an anchored implant device 304 may include a baseplate 310 and an anchor 324. In the example depicted in FIG. 3A, implant device 304 is in an unassembled state, with baseplate 310 and anchor 324 disconnected.

[0088] Baseplate 310 may include an anterior side 346 and a posterior side 345, and a top or proximal surface 343 (configured to engage a femoral knee implant (not shown) or to support a bearing, insert, or other structure configured to engage the femoral knee implant) and a bottom or distal surface 344 configured to engage the tibia (for instance, a resected or otherwise prepared portion of the tibia). A slot 340 may be arranged within baseplate 310 that is configured to receive anchor 324. Slot 340 may include one or more baseplate engagement structures 342 configured to engage with one or more corresponding anchor engagement structures 330 of a top portion 335 of anchor 324 to prevent anchor 324 from moving all the way through slot 340.

[0089] In some embodiments, baseplate engagement structures 342 and anchor engagement structures 330 may be complementary, for instance, to engage each other. In various embodiments, baseplate engagement structures 342 may include ridges, shoulders, grooves, and/or the like and anchor engagement structures 330 may include protrusions, posts, and/or the like configured to engage the ridges, shoulders, grooves, and/or the like of baseplate engagement structures 342 (or vice versa, for instance, in which anchor engagement structures 330 include ridges and/or the like and baseplate engagement structures 342 include corresponding protrusions).

[0090] According to some embodiments, baseplate 310 may be arranged on a prepared bone surface and anchor 324 would be fitted through slot 340, for example, in a superior- inferior direction or substantially superior-inferior direction, such that anchor 324 may compress against the prepared section of bone and hold baseplate 310 (for instance, via engagement of baseplate engagement structures 342 and anchor engagement structures 330) to the prepared proximal tibia. In this manner, anchor 324 may provide a press-fit fixation mechanism for baseplate 304 without violating the bony cortex of the tibia.

[0091] Referring to FIGS. 3B and 3C, therein is depicted an assembled anchored implant device 304. More specifically, FIG. 3B depicts a perspective top-down view of assembled implant device 304 and FIG. 3C depicts a side view of assembled implant device 304. As shown in FIG. 3B, upper portion 335 of anchor 324 may be maintained within a portion of slot 340, while a remainder of anchor 324 protrudes through baseplate 310 and into the prepared section of bone.

[0092] As shown in FIGS. 3A-3C, anchor 324 may include one or more edges or surfaces 331, 334 that may protrude into a prepared tibial interior space. For example, surface 331 may be a leading edge or surface of anchor configured to be installed within the interior space of a prepared tibia (for instance, below the prepared proximal area of the tibia configured to engage distal side 344 of baseplate 310). In some embodiments, edges 331, 334 may form a fin or keel. In various embodiments, edges 331, 334 may be curved, sloped, beveled, straight, or have a variety of other shapes or forms. Edges 331, 334 may be configured to enhance fixation of implant device 304 to patient bone while minimizing the amount of bone removal during bone preparation through press- or compression fitting, for example, by force-fitting the larger body of the bottom portion of anchor 324 (for instance, edges 331, 334) into a smaller preparation of the bone. In exemplary embodiments, the portion of anchor 324 that enters the prepared bone region may include one or more openings, cavities, porous regions, and/or the like 332. The bone will grow in the prepared region following the arthroplasty procedure and ingrowth of bone will egress into openings 332 to enhance the fixation of implant device 304 to the tibia.

[0093] Implant devices described in the present disclosure, including implant device 304, may be configured as a unicompartmental implant device, a TKA device, a bi-condylar implant device, or any other type of implant device capable of operating according to some embodiments, unless specifically claimed otherwise. In some embodiments, at least a portion of implant devices may be cementless and/or fastener-less implant devices affixed to bone via press fitting and/or bone ingrowth. In various embodiments, implant devices may use cement or other adhesives to augment fixation. In exemplary embodiments, implant devices may use fasteners, such as screws, to augment fixation. In some embodiments, anchored implant devices, such as those depicted in FIGS. 3A-5C, may use other press-fit members, such as pegs, projections, keels, fins, contoured (non flat) surfaces, and/or the like. [0094] FIG. 3D illustrates a cross-sectional view of installment of anchor 324 and baseplate 310 on a prepared surface 302 of a proximal end of a tibia 301. Step 361 depicts the placement of baseplate 310 on prepared surface 302. In step 362, anchor 324 is pushed through slot 340 into the prepared bone to form a compression fit between anchor 324 and the prepared bone. For example, surface 331 of anchor 324 may form a press-fit with interior surfaces of tibia 301 within which it is installed, holding anchor 324 in place. Engagement between anchor engagement structures 330 and baseplate engagement structures 342 may cause anchor 324 to hold baseplate 310 in place on prepared surface 302. With an expected or normal fit, distal surface 344 is flush (or substantially flush) with prepared surface 302.

[0095] In some embodiments, an adjustable mounting feature of baseplate 310 may be used to achieve an expected or normal flush mounting of baseplate 310 on prepared surface 302, for instance, if anchor 324 is located in an abnormal position, for instance, at a higher or more superior position (with respect to prepared surface 302) (see, for example, FIGS. 3E, 4E, 12A, and 12B).

[0096] In a typical or normal installation, an anchor (or other fixation element) may be installed at a depth within the bone such that the baseplate may be mounted flush with the prepared bone surface. In general, a flush installation of the baseplate includes an installation such that the baseplate rests or substantially rests on the prepared bone surface and there is no or substantially no space between the baseplate and the prepared bone surface (although there may be some areas of spacing due to contours, etc. in the prepared surface).

[0097] In certain abnormal installations (and/or configurations due to post-installation movement of an anchor or other fixation element), an anchor may be installed at a depth that is not as deep as required, such that the anchor sticks out of the bone higher than planned. In such abnormal conditions, fixation elements (i.e., anchors) of prior art fixation element-based implant devices may act to support or hold the baseplate above the prepared surface (i.e., the anchor could become the primary load-bearing element of the baseplate, instead of the prepared bone surface), creating a condition vulnerable to failure, including mechanical failure of the implant device, damage to patient anatomy, patient pain/discomfort, degraded implant performance, and/or the like.

[0098] FIG. 11 illustrates a prior-art fixation element implant device. As shown in FIG. 11, a fixation element implant device 1101 may include a baseplate 1115 and a fixation element 1135 that is configured to be installed within a bone structure, such as the proximal end of a tibia 1130. Baseplate 1115 is configured to be affixed in place on prepared surface 1131 of tibia 1130 via rigid engagement with fixation element 1135. For example, implant device 1101 may include a slot, groove, or other structure 1125 configured to engage fixation element 1135 so that fixation element 1135 affixes baseplate 1115 to tibia 1130.

[0099] In a normal installation, fixation element 1135 may be installed at a depth within tibia such that baseplate 1115 may be seated with bottom surface 1116 of baseplate 1115 flush or substantially flush with prepared surface 1131 of tibia 1130 (i.e., baseplate 1115 is resting on prepared surface 1131; there is no gap or substantially no gap between bottom surface 1116 and prepared surface 1131). However, with prior art element implant devices, such as implant device 1101, portions of fixation device 1135 may prevent flush placement of baseplate 1115, for example, if fixation device 1135 is not installed to a proper depth within tibia 1130 (e.g., at least a portion of fixation device 1135 is installed higher or superior to an expected depth).

[0100] For example, a top side, ridge, or other structure 1105 of fixation device 1135 may engage a portion of baseplate 1115, such as a portion of structure 1125, to prevent baseplate 1115 from meeting with prepared surface 1131. In such an abnormal installation, fixation device 1135 is actually supporting baseplate 1115 and there is a gap 1150 between at least a portion of baseplate 1115 and prepared surface 1131. With prior art element implant devices, baseplate 1115 and/or fixation element 1135 is not configured to allow movement of baseplate 1115, for example, in a superior- inferior direction A (and, in particular, in an inferior direction B to close gap 1150) to allow baseplate to meet prepared surface. Rather, fixation element 1135 rigidly engages baseplate and acts to hold up and support baseplate 1115 above prepared surface.

[0101] Accordingly, in some embodiments, an anchored implant device may be configured to facilitate adjustable mounting of a baseplate about a fixation element (e.g., an anchor) to allow for flush mounting of a baseplate on a prepared surface of bone, including when there is abnormal installation of a fixation element (e.g., at least a portion of the fixation element sticks out further from the bone than expected, at least a portion of the fixation element prevents flush mounting of the baseplate, and/or the like) (see, for example, FIGS. 3E, 4E, 12A, 12B, 13C, and 13D).

[0102] For example, in some embodiments, a baseplate may be configured to engage an anchor such that the anchor may hold the baseplate in position on or about a prepared bone surface, while allowing for translation in a superior-inferior direction. Accordingly, anchored implant devices according to some embodiments may allow for adjustable mounting in which a baseplate may move toward a prepared bone surface in an abnormal installation (e.g., the anchor is not installed to a required depth, a portion of the anchor blocks flush mounting of the baseplate (for instance, via misalignment of engagement structures), and/or the like) to allow the baseplate to be flush or substantially flush with the prepared bone surface.

[0103] FIGS. 12A and 12B illustrate adjustable mounting of an anchored implant device in accordance with one or more features of the present disclosure. As shown in FIG.

12 A, an anchored implant device 1204 may include a baseplate 1210 and an anchor 1224. Baseplate 1210 may include a distal side 1246 and a structure 1240 configured to engage at least a top portion 1205 of anchor 1224. Structure 1240 may be or may include a slot, ridge, groove, protrusions, and/or the like (see, for example, FIGS. 3 A and 4A). In some embodiments, structure 1240 (and/or anchor 1224) may be configured to allow baseplate 1210 to translate in a superior- inferior direction or substantially superior- inferior direction (e.g., in a direction toward and/or away from prepared surface 1202) A. [0104] Referring to FIG. 12A, line 1253 indicates an expected depth of anchor 1224 and line 1251 is the actual depth of anchor 1224 (i.e., anchor is installed higher, or more superior, than expected). Referring to FIGS. 12A and 12B, the configuration of baseplate 1210 (or structure 1240) allows for baseplate 1210 to translate in a superior-inferior direction A and, in particular, in an inferior direction or substantially inferior direction B (e.g., in a direction toward prepared surface 1202) to close any gap 1252 between a distal side 1246 of baseplate 1210 and prepared surface 1202. In various embodiments, baseplate 1210 may also move in superior direction or substantially superior direction C. In various embodiments, baseplate 1210 may be prevented from moving in superior direction C beyond a certain distance due to engagement structures of anchor 1224. As shown in FIG. 12B, baseplate 1210 is able to be seated flush or substantially flush with prepared surface 1202 (despite an abnormal installation or configuration of anchor 1224).

[0105] Accordingly, in some embodiments, structure 1240 may operate to hold or loosely hold baseplate 1210 and anchor 1224 together, while allowing for some adjustment, “play,” movement, superior-inferior translation, inferior translation, superior translation, translation toward a prepared tibial surface, and/or the like. The amount of adjustment (e.g., the distance the baseplate may move in an anterior-inferior direction, a superior direction, and/or an inferior direction about the anchor) may depend on various factors.

In some embodiments, the amount of adjustment distance may be about 0.25 mm, about 0.5 mm, about 1.0 mm, about 1.5 mm, about 2 mm, about 2.5 mm, about 3.0 mm, about 3.5 mm, about 4.0 mm, about 4.5 mm, about 5 mm, about 10 mm, and any value or range between any two of these values (including endpoints). [0106] Referring to FIG. 3E, configuration 391 depicts an abnormal condition or configuration in which baseplate 310 is not flush with prepared surface 302 (arrow 370 indicates a gap between baseplate 310 and prepared surface 302).

[0107] In a prior art implant device (i.e., FIG. 11), the baseplate would then be supported by the anchor because there is no adjustment feature that allows baseplate and anchor to translate in a superior- inferior relative direction A (or an inferior direction B). However, as shown in configuration 392, baseplate 310 is configured to allow for inferior movement in direction B so that baseplate may rest on prepared surface 302. For example, in some embodiments, protrusions 330 may ride within ridges 342 (while still remaining seated within ridges 342) to allow for some adjustment of baseplate 310. As shown in FIG. 3D, protrusions 330 are seated in a bottom surface 349 (or against a bottom surface) of ridges 342. As shown in FIG. 3E, protrusions 330 are positioned above (and not resting upon) bottom surface 349, while protrusions 330 are still arranged within ridges 342.

[0108] FIGS. 4A-4C illustrate various views of a second embodiment of an anchored implant device in accordance with one or more features of the present disclosure. As shown in FIG. 4A, an anchored implant device 404 may include a baseplate 410 and an anchor 424. In the example depicted in FIG. 4A, implant device 404 is in an unassembled state, with baseplate 410 and anchor 424 separated.

[0109] Baseplate 410 may include an anterior side 446 and a posterior side 445, and a top or proximal surface 443 and a bottom or distal surface 444. A slot 440 may be arranged within baseplate 410 that is configured to receive a top portion 435 of anchor 424. Slot 440 may include one or more baseplate engagement structures 441 (e.g., ridges, flanges, shoulders and/or other structures) configured to engage with one or more corresponding anchor engagement structures 435 (e.g., a top portion) of anchor 424 to mount or otherwise couple anchor 424 to baseplate 410. In some embodiments, ridges 441 and top portion 435 may be complementary, for instance, to engage each other. For example, top portion 435 may form a flange or protrusion that is too wide to fit through slot 440. In some embodiments, top portion 435 may be sized and/or shaped to be seated on ridge 441. In other embodiments, top portion 435 may engage a top surface of baseplate 410, for example, surrounding at least a portion of slot 440.

[0110] According to some embodiments, anchor 424 may be rigidly press-fitted into the prepared section of the tibia. Baseplate 410 may slide over anchor 424 such that top portion 435 moves through slot and fixedly engages ridge 441 to compress and lock baseplate 410 to the prepared proximal tibia. In this manner, anchor 424 may provide a press-fit fixation mechanism for baseplate 410 without violating the bony cortex of the tibia.

[0111] Referring to FIGS. 4B and 4C, therein is depicted an assembled anchored implant device 404. More specifically, FIG. 4B depicts a perspective top-down view of assembled implant device 404 and FIG. 4C depicts a side view of assembled implant device 404. As shown in FIG. 4B, upper portion 435 of anchor 424 may be maintained within a portion of slot 440 (for instance, engaged with ridge 441), while a remainder of anchor 424 protrudes through baseplate 410 and into the prepared section of bone.

[0112] In some embodiments, baseplate 410 may include one or more protrusions, for example, extending from bottom surface 444, and/or slot 440 area to lock (or further engage) baseplate 410 onto (or to) anchor 424. In various embodiments, anchor 424 may be arranged in the prepared bone area and baseplate 410 may be placed over anchor 424, then anchor 424 may be moved (for instance, in an anterior-posterior, anterior/superior- posterior- inferior direction, and/or the like) to lock baseplate 410 in place.

[0113] As shown in FIGS. 4A-4C, anchor 424 may include one or more edges or surfaces 431, 434 that may protrude into a prepared tibial surface. In exemplary embodiments, the portion of anchor 424 that enters the prepared bone region may include one or more openings 432 to allow for bone ingrowth to enhance the fixation of implant device 404 to the tibia.

[0114] FIG. 4D illustrates a cross-sectional view of installment of anchor 424 and baseplate 410 on a prepared surface 402 of a proximal end of a tibia 401. In step 461, anchor 424 has been implanted within tibia 401. Step 462 depicts baseplate 410 being installed onto prepared surface 402 such that slot 440 envelopes top portion 435 of anchor 424. In step 463, baseplate may be moved forward 470 such that slot 440 engages with top portion 435 to mount or otherwise couple baseplate 410 to anchor 424. With an expected or normal fit, baseplate 410 is flush (or substantially flush) with prepared surface 402. [0115] In some embodiments, an adjustable mounting feature of baseplate 410 may be used to achieve an expected or normal flush mounting of baseplate 410 on prepared surface 402, for instance, if anchor 424 is located in an abnormal position, for instance, at a higher or more superior position (with respect to prepared surface 402). Referring to FIG. 4E, configuration 491 depicts an abnormal condition in which baseplate 410 is not flush with prepared surface 402 (arrow 471 indicates a gap between baseplate 410 and prepared surface 402).

[0116] In a prior art implant device (i.e., FIG. 11), the baseplate would then be supported by the anchor because there is no adjustment feature that allows baseplate and anchor to translate in a superior-inferior relative direction or substantially superior-inferior relative direction A. However, as shown in configuration 492, baseplate 410 is configured to allow for inferior or substantially inferior movement in direction B (i.e., toward prepared surface 402) so that baseplate may rest on prepared surface 402.

[0117] For example, in some embodiments, top surface 435 may ride within slot 440 to allow for some adjustment of baseplate 410. In some embodiments, for example, top surface 435 may rest on ridge 441. In various embodiments (for example, in configuration 493), top surface 435 may be positioned above ridge 441; however, top surface 435 may prevent baseplate 410 from moving in a superior direction beyond a certain limit (e.g., top surface 435 may loosely hold baseplate 410 in place on prepared surface 402). [0118] FIGS. 5A-5C illustrate various views of a third embodiment of an anchored implant device in accordance with one or more features of the present disclosure. As shown in FIG. 5A, an anchored implant device 504 may include a baseplate 510 and an anchor 524. In the example depicted in FIG. 5A, implant device 504 is in an unassembled state, with baseplate 510 and anchor 524 separated.

[0119] Baseplate 510 may include an anterior side 546, a posterior side 545, a top or proximal surface 543, and a bottom or distal surface 544. In some embodiments, baseplate 510 may include a keel or fin 526 protruding from bottom surface 544. A slot 540 may be arranged within baseplate 510 that is configured to receive anchor 524. Slot 540 may include one or more baseplate engagement structures 541 (e.g., ridges, flanges, shoulders, and/or other structures) configured to engage a corresponding anchor engagement structure of anchor, such as a portion of anchor 524 (for instance, top portion 535) to affix anchor 524 to baseplate 510.

[0120] According to some embodiments, baseplate 510 may be arranged on tibia via keel 526 being inserted into the prepared bone area. In some embodiments, keel 526 may provide a press fit to affix baseplate 510 to tibia. In various embodiments, keel 526 may not provide a press fit with the prepared bone area. Keel 526 (and/or anchor 524) may include openings 532 to allow for bone ingrowth to enhance the fixation of implant device 504 to the tibia. Referring to FIGS. 5B and 5C, anchor 524 may be pushed through slot 540 and into the prepared bone area. FIG. 5B depicts an unassembled side view of implant device 504, and FIG. 5C depicts an assembled side view of implant device 504.

[0121] In various embodiments, anchor 524 may be formed to slide through slot 540 and around or adjacent to edge 531 of keel 526 within the prepared section of the tibia. In some embodiments, anchor 524 may have a slot or channel 542 configured to receive edge 531 when anchor 524 is pushed through slot and into the prepared portion of bone. In some embodiments, edge 531 may have a protrusion configured to engage a corresponding ridge (or similar corresponding structure) on anchor 524 (or within channel 542), or vice versa, such that anchor 524 mates rigidly with keel 526. Either way, in some embodiments, anchor 524 and keel 526 may have corresponding structures such that anchor 524 and keel 526 may be engaged or mated when implant device 504 is in the assembled state. In some embodiments, anchor 524 may be rigidly press-fitted into the prepared section of the tibia to affix baseplate 510 to tibia.

[0122] In various embodiments, baseplate 510 (including slot 540 and/or ridges 541) and/or anchor 524 may be configured to allow for an adjustment feature according to some embodiments. For example, baseplate 510 may be configured to move in an inferior- superior direction, an inferior direction, and/or a superior direction with respect to prepared surface 502 about anchor 524.

[0123] U.S. Patent Application Publication No. 2021/0290410, titled “Unicompartmental Knee Arthroplasty,” depicts fixation element implant devices, and is incorporated by reference as if fully set forth in the present disclosure (the ‘410 Application). FIGS. 13A-13D illustrate various views of a fourth embodiment (related to the devices disclosed in the ‘410 Application) of an anchored implant device in accordance with one or more features of the present disclosure.

[0124] Referring to FIGS. 13A-13D, therein is depicted a knee tibial prosthesis 1310 that may include a tibial component 1350 and at least one fixation element 1320. Tibial component 1350 may be referred to as a tibial tray 1350. The illustrated tibial component 1350 is a unicompartmental tibial component. A "tibial component" may be an implantable device such as tibial component 1350, or in alternative embodiments, may instead be an instrument such as a guide, a tool, a jig, or the like, that facilitates alignment and/or placement of an implant and/or components thereof. Tibial prosthesis 1310 may include one fixation element 1320, which may be referred to as an anchor 1320. Multiple anchors may be present. Anchor 1320 may be inserted from an anterior edge 1354 of tibial tray 1350 and may be oriented roughly anterior-posterior, as shown. Anchor 1320 may be parallel or angled relative to another anchor (if present) and/or tray 1350. Anchor 1320 may also be tilted with respect to tray 1350, for example, tilted medially or laterally. Anchor 1320 is inserted into a channel 1352 in tibial tray 1350 (FIGS. 13C and 13D). Multiple channels may be present. Channel 1352 may be dovetailed as shown; other undercut channel geometries are contemplated, such as T- slots. In some embodiments, as shown in FIGS. 13A-13D, channel 1352 may extend between anterior and posterior edges 1354, 1366 of tray 1350. In some embodiments, tibial prosthesis 1310 may include one or more secondary fixation elements 1357, 1358 that may include, for example and without limitation, at least one of a keel, a fin, a projection, a groove, a peg, and/or the like.

[0125] In some embodiments, channel 1352 may only open at one of the anterior and posterior edges 1354, 1366, and may terminate in the main body of tray 1350. In various embodiments, channel 1352 may be oriented exactly anterior-posterior, exactly medial- lateral, generally medial-lateral, or in another orientation. A channel 1352 may open through any perimeter edge of a bone-contacting side 1356 of tray 1350.

[0126] In various embodiments, tibial tray 1350 may further include a joint-facing, or superior side 1360 to which an articular insert (not shown) may be mounted, or joint facing side 1360 may include a prosthetic articular surface integrally formed with tibial tray 1350. A raised rim 1362 may encompass superior side 1360, and overhangs 1364 may be formed on a portion of rim 1362 for engagement with an articular insert and/or instruments. Rim 1362 and overhangs 1364 together define a recess 1363 that may receive an articular insert and may also engage an anchor guide instrument (not shown). The articular insert or instrument may engage under overhangs 1364 to be held rigidly in tray 1350, for example, by a snap fit. Tibial tray 1350 may be described as a unicondylar tibial component because it is adapted to extend across a single resected tibial condyle to replace the medial or lateral condyle. In some embodiments, channel 1352 may be defined between first and second walls 1377, 1378.

[0127] In some embodiments, tibial tray 1350 may be configured to have an adjustment feature according to various embodiments. In various embodiments, tray 1350 may move in a superior-inferior direction A about anchor 1320 (or, in some embodiments, in an inferior direction or a superior direction). Referring to FIGS. 13C and 13D, channel 1352 may be sized, shaped, or otherwise configured to have a space 1370 (shaded area) between a top surface or wall 1353 (or most proximal surface) of channel 1352 that allows tray 1350 to move in a superior-inferior direction A (while sidewalls 1377 and 1378 prevent complete detachment of anchor 1320 from tray 1350). Accordingly, anchor 1320 may reside within channel 1352, while allowing for some adjustment (or “play”) of anchor 1320 or of tray 1350 about anchor 1320 (for instance, toward and/or away from a prepared surface of a tibia).

[0128] Conventional implant procedures operate to prepare flat bone surfaces due to available cutting tools. Computer-assisted surgical systems, such as system 100 depicted in FIG. 1, may facilitate contoured (non-flat) surfaces with various geometries and 3D surface effects. However, conventional implant devices are limited to engaging with flat, planar prepared surfaces because the implant devices do not include 3D geometries that may be able to provide additional fixation.

[0129] Accordingly, some embodiments may provide contoured implant devices that include non-flat, non-planar, contoured surfaces, as well as projections (or, conversely, recesses) and/or other 3D structures that may correspond with 3D surfaces and structures that may be made in prepared bone surfaces using computer-assisted or robotic surgical systems. [0130] For example, in some embodiments, a contoured implant device may include a modular unicondylar tibia implant with a 3D contoured distal bone facing surface that may be primarily concave, primarily convex, or a combination of concavity and convexity. In some embodiments, corresponding contoured surfaces of patient anatomy may be prepared to engage a contoured implant device by an instrument that is orientable in all 6 degrees of freedom and capable of producing a freeform 3D surface (e.g., a robotic spherical burr). In some embodiments, contoured implant devices may be customized for an individual patient or selectable from a standard set of sizes, and may include secondary fixation features such as keels, pegs, fins, projections, anchors, and/or the like which may themselves have tertiary fixation features such as slots or grooves. In addition, a distal surface of a baseplate of a contoured implant device may also include tertiary slots or grooves or other structures described in the present disclosure.

[0131] In some embodiments of a contoured implant device, the distal bone facing surface may have independent geometry of the proximal/articular surface such that the surface is designed to match inherent internal properties of the tibia condylar bone once prepared for the implant. This surface may also be independent of the native tibia proximal surface geometry such as cartilage or exposed bone, for example, such that the entirety of the proximal surface may be prepared to receive this implant. Accordingly, contoured implant devices according to some embodiments may be configured to target improved fixation over a traditional flat preparation and/or to preserve strength of bone by targeting bone removal where strength of retained bone is maximized, and stress concentrations are minimized. [0132] FIGS. 6A-6F illustrate various views of a first embodiment of a contoured implant device in accordance with one or more features of the present disclosure. Referring to FIGS. 6 A and 6B, therein is depicted an oblique or perspective view of a contoured implant device 604 having an anterior side 646 and a posterior side 645, and a top or proximal surface 643 (configured to engage a femoral knee implant (not shown) or to support a bearing, insert, or other structure 612 configured to engage the femoral knee implant) and a bottom or distal surface 644 configured to engage the tibia (for instance, a resected or prepared portion of the tibia). In some embodiments, baseplate 610 may be configured to support an insert 612 operative to engage a corresponding structure on a femoral implant of a knee arthroplasty system.

[0133] In some embodiments, various surfaces of implant device 604 may be contoured. For example, in various embodiments, at least a portion of distal side 644 may have a contoured feature, such as a convex portion 660. In exemplary embodiments, convex portion 660 may be configured to engage a corresponding portion of a prepared knee (for instance, a concave portion prepared by a robotic surgery system).

[0134] In various embodiments, a contour of a portion of implant devices described in accordance with the present disclosure, such as implant device 604, may be formed in a 3D plane. In other embodiments, a contour may be formed in a 2D plane (for instance, only in the sagittal plane) or 2D on multiple surfaces (for instance, only in the sagittal view on the distal surface, and only in a distal view of the spine surface), or a combination of 3D on one surface and 2D on another surface, or other combinations. Embodiments are not limited in this context.

[0135] FIGS. 6C and 6D depict a cross section and a side section of contoured implant device, respectively. FIGS. 6E and 6F depict a bottom and top oblique or perspective view, respectively.

[0136] Referring to FIGS. 6E and 6F, therein are depicted secondary fixation features. For example, in the embodiment of FIGS. 6E and 6F, contoured implant device may include pegs 630, keel 632, and projections (for instance, ridges) 634. In various embodiments, secondary fixation features may also include contoured features, for example, pegs 630 may include grooves 631. Secondary fixation features may provide additional structures for affixing contoured implant device to a corresponding prepared bone structure. In various embodiments, bone preparation methods may include preparing corresponding contoured bone surfaces that are formed to match or receive the secondary fixation structures (for instance, contoured slots to match pegs 630 and grooves 631, slots to match ridges 634, and/or the like).

[0137] FIGS. 7A-7F illustrate various views of a second embodiment of a contoured implant device in accordance with one or more features of the present disclosure. Referring to FIGS. 7 A and 7B, therein is depicted an oblique or perspective view of a contoured implant device 704 having an anterior side 746 and a posterior side 745, and a top or proximal surface 743 and a bottom or distal surface 744. In some embodiments, baseplate 710 may be configured to support an insert 712 operative to engage a corresponding structure on a femoral implant of a knee arthroplasty system.

[0138] In some embodiments, various surfaces of implant device 704 may be contoured. For example, in various embodiments, at least a portion of distal side 744 may have a concave portion 760. In exemplary embodiments, concave portion 760 may be configured to engage a corresponding portion of a prepared knee (for instance, a convex portion prepared by a robotic surgery system).

[0139] FIGS. 7C and 7D depict a cross section and a side section of contoured implant device, respectively. FIGS. 7E and 7F depict a bottom and top oblique or perspective view, respectively.

[0140] Referring to FIGS. 7E and 7F, therein are depicted secondary fixation features. For example, in the embodiment of FIGS. 7E and 7F, contoured implant device may include pegs 730, keel 732, and projections (for instance, ridges) 734. In various embodiments, secondary fixation features may also include contoured features. Secondary fixation features may provide additional structures for affixing contoured implant device to a corresponding prepared bone structure. In various embodiments, bone preparation methods may include preparing corresponding contoured bone surfaces that are formed to match or receive the secondary fixation structures.

[0141] FIGS. 8A-8F illustrate various views of a third embodiment of a contoured implant device in accordance with one or more features of the present disclosure. Referring to FIGS. 8 A and 8B, therein is depicted an oblique or perspective view of a contoured implant device 804 having an anterior side 846 and a posterior side 845, and a top or proximal surface 843 and a bottom or distal surface 844. In some embodiments, baseplate 810 may be configured to support an insert 812 operative to engage a corresponding structure on a femoral implant of a knee arthroplasty system.

[0142] In some embodiments, various surfaces of implant device 804 may be contoured. For example, in various embodiments, at least a portion of distal side 844 may have projections 836 (and corresponding recesses 837), bumps, protrusions, or other structures extending from distal side 844. Although a plurality of projections 836 and recesses 837 in the figures, only one is labeled to simplify the depicted embodiments. In general, distal side 844 has a contour that is a mixture of convex (projections 836) and concave (recesses 837) features. In exemplary embodiments, projections 836 (and corresponding recesses 837) may be configured to engage a corresponding portion of a prepared knee (for instance, one or more corresponding projections and/or recesses). In some embodiments, in addition to projections 836, distal surface 844 may have other 3D geometric features, such as being concave, convex, slanted, angled, and/or the like, and/or combinations thereof.

[0143] FIGS. 8C and 8D depict a cross section and a side section of contoured implant device, respectively. FIGS. 8E and 8F depict a bottom and top oblique or perspective view, respectively. [0144] Referring to FIGS. 8E and 8F, therein are depicted secondary fixation features. For example, in the embodiment of FIGS. 8E and 8F, contoured implant device may include pegs 830, keel 832, and/or the like. In various embodiments, secondary fixation features may also include contoured features. Secondary fixation features may provide additional structures for affixing contoured implant device to a corresponding prepared bone structure. In various embodiments, bone preparation methods may include preparing corresponding contoured bone surfaces that are formed to match or receive the secondary fixation structures.

[0145] FIGS. 9A-9F illustrate various views of a fourth embodiment of a contoured implant device in accordance with one or more features of the present disclosure. Referring to FIGS. 9 A and 9B, therein is depicted an oblique or perspective view of a contoured implant device 904 having an anterior side 946 and a posterior side 945, and a top or proximal surface 943 and a bottom or distal surface 944. In some embodiments, baseplate 910 may be configured to support an insert 912 operative to engage a corresponding structure on a femoral implant of a knee arthroplasty system.

[0146] In some embodiments, various surfaces of implant device 904 may be contoured. For example, in various embodiments, at least a portion of distal side 944 may have a protruding ridge 938 extending from distal side 944. In various embodiments, ridge 938 may enclose a recess or indented region 937. In exemplary embodiments, ridge 938 may be configured to engage a corresponding portion of a prepared knee (for instance, one or more corresponding grooves). In some embodiments, in addition to ridge 938, distal surface 944 may have other 3D geometric features, such as being concave, convex, slanted, angled, and/or the like, and/or combinations thereof.

[0147] FIGS. 9C and 9D depict a cross section and a side section of contoured implant device, respectively. FIGS. 9E and 9F depict a bottom and top oblique or perspective view, respectively.

[0148] Referring to FIGS. 9E and 9F, therein are depicted secondary fixation features. For example, in the embodiment of FIGS. 9E and 9F, contoured implant device 904 may include pegs 930, keel 932, and/or the like. In another example, contoured implant device 904 may include recesses 935 formed in distal side 944, including on or about ridge 938 and indented region 937. In various embodiments, secondary fixation features may also include contoured features. Secondary fixation features may provide additional structures for affixing contoured implant device to a corresponding prepared bone structure. In various embodiments, bone preparation methods may include preparing corresponding contoured bone surfaces that are formed to match or receive the secondary fixation structures.

[0149] FIGS. 10A and 10B illustrate various views of a fifth embodiment of a contoured implant device in accordance with one or more features of the present disclosure. Referring to FIGS. 10A and 10B, therein is depicted an oblique or perspective view of a contoured implant device 1004 having a top or proximal surface 1043 and a bottom or distal surface 1044. In some embodiments, baseplate 1010 may be configured to support an insert 1012 operative to engage a corresponding structure on a femoral implant of a knee arthroplasty system.

[0150] In some embodiments, various surfaces of implant device 1004 may be contoured. For example, in various embodiments, at least a portion of distal side 1044 may have projections 1036 (and corresponding recesses 1037), bumps, protrusions, or other structures extending from distal side 1044. In general, distal side 1044 has a contour that is a mixture of convex (projections 1036) and concave (recesses 1037) features. In some embodiments, in addition to projections 1036, distal surface 1044 may have other 3D geometric features, such as being concave, convex, slanted, angled, and/or the like, and/or combinations thereof.

[0151] In some embodiments, other surfaces of contoured implant device 1004 may have contoured features in addition to or in the alternative to distal side 1044. For example, as depicted in FIG. 10A, spine-facing (or posterior) side 1050 may include a concave or convex surface. Referring to FIG. 10B, spine-facing side 1050 may include a concave and convex portion 1048, for example, that includes a series of projections and corresponding recesses. In various embodiments, additional and/or alternative surfaces, sides, or other portions of contoured implant device 1004 may have contoured surfaces and/or secondary fixation elements. For example, contoured surfaces and/or secondary fixation elements may be arranged on a distal side, a proximal side, an anterior side, a posterior side, combinations thereof, and/or the like. Embodiments are not limited in this context. [0152] Implant devices described according to various embodiments and/or components thereof may be made from various materials. Non-limiting example materials may include titanium, cobalt chrome, stainless steel, ceramic, polymers, variations thereof, alloys thereof (if applicable), combinations thereof, coatings thereof (for example, each of the aforementioned materials may be included as a coating for any other material), and/or other biocompatible materials. In some embodiments, the exterior surface of any component of implant devices may be porous and/or semi-porous. Various manufacturing techniques may be used to manufacture components of implant devices. For example, components of implant devices may be cast, additively manufactured, molded, machined, printed (for instance, via three-dimensional (3D) printing techniques), combinations thereof, and/or the like. In some embodiments, one or more components of implant devices may be made from different materials than other components.

[0153] In one non-limiting example of an anchored implant device, a baseplate may be made from a first metal material (for instance, a first titanium alloy), the insert may be made from a polymer material, and the anchor may be made from a second metal material (for instance, a second titanium alloy). In one non-limiting example of a contoured implant device, a baseplate may be made from a first metal material (for instance, a first titanium alloy), the insert may be made from a polymer material, and a secondary fixation element (for instance, pegs, keels, and/or the like) may be made from a second metal material (for instance, a second titanium alloy). In various embodiments of a contoured implant device, the baseplate and secondary fixation devices may be formed from an integral piece. In other embodiments of a contoured implant device, the baseplate and secondary fixation devices may be formed separately, and the secondary fixation devices may be affixed to the baseplate. Embodiments are not limited in this context.

[0154] The foregoing description has broad application. Accordingly, the discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these example embodiments.

In other words, while illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.

[0155] The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof are open-ended expressions and can be used interchangeably herein. The phrases “at least one,” “one or more,” and “and/or,” as used herein, are open- ended expressions that are both conjunctive and disjunctive in operation.

[0156] All directional references (e.g., proximal, distal, upper, underside, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of this disclosure. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order, and relative sizes reflected in the drawings attached hereto may vary.

Claims

CLAIMS What is claimed is:

1. An anchored tibial implant device, comprising: a baseplate configured to be arranged on a prepared surface of a proximal end of a tibia, the baseplate comprising at least one slot and at least one baseplate engagement structure; and an anchor, separate from the baseplate, configured to be arranged within the slot and within at least a portion of the proximal end of the tibia at least partially below the prepared surface, the anchor comprising: at least one edge configured to engage bone within the tibia, and at least one anchor engagement structure configured to engage the at least one baseplate engagement structure to hold the baseplate on the prepared surface of the tibia, wherein the baseplate engagement structure is configured to facilitate adjustable mounting of the baseplate about the anchor on the prepared surface.

2. The anchored tibial implant device of claim 1, wherein the adjustable mounting allows movement of the baseplate in a superior-inferior direction.

3. The anchored tibial implant device of claim 1, wherein the adjustable mounting allows movement of the baseplate to facilitate flush mounting of the baseplate against the prepared surface in an abnormal configuration of anchor.

4. The anchored tibial implant device of claim 1, wherein the baseplate engagement structure is configured to facilitate movement of the baseplate in an inferior direction toward the prepared surface to facilitate flush mounting of the baseplate against the prepared surface in an abnormal configuration of anchor.

5. The anchored tibial implant device of any of claims 1 to 4, the at least one baseplate engagement structure comprising at least one ridge.

6. The anchored tibial implant device of claim 5, the at least one anchor engagement structure comprising at least one protrusion configured to be seated within the at least one ridge.

7. The anchored tibial implant device of any of claims 1 to 5, the at least one baseplate engagement structure comprising a plurality of ridges, and the at least one anchor engagement structure comprising a plurality of protrusions, each of the plurality of protrusions configured to be seated within one of the plurality of ridges.

8. The anchored tibial implant device of any of claims 1 to 7, the anchor configured to be installed through the slot of the baseplate arranged on the prepared surface of the tibia.

9. The anchored tibial implant device of claim 5, the at least one anchor engagement structure comprising at least one flange configured to be seated on the at least one ridge.

10. The anchored tibial implant device of any of claims 1 to 3, the baseplate configured to be installed over the anchor arranged within the tibia.

11. The anchored tibial implant device of any of claims 1 to 3, the baseplate comprising a keel configured to be arranged within at least a portion of the proximal end of the tibia at least partially below the prepared surface, the at least one anchor engagement structure comprising a channel configured to fixedly engage an edge of the keel.

12. A contoured tibial implant device, comprising: a three-dimensionally (3D) contoured first surface, the first surface configured to be arranged on a prepared surface of a tibia; and a 3D contoured second surface, the second surface configured to engage a femur or a femur component of a knee joint.

13. The contoured tibial implant device of claim 12, the 3D contoured first surface shaped to correspond to a corresponding 3D resectioned surface of the prepared surface prepared by a computer-assisted surgical system.

14. The contoured tibial implant device of claim 12 or 13, comprising at least one contoured feature on at least one of a medial surface or a lateral surface.

15. The contoured tibial implant device of any of claims 12-14, the first surface comprising a mixture of convex projections and concave recesses.