Device for setting thickness during total knee arthroplasty

Abstract

Described herein are mechanical, self-contained, non-implantable devices for setting polyethylene thickness during pilot-scale trial and equilibrium of total knee arthroplasty. These adjustable trial tibial pad devices may be used with total knee arthroplasty (TKA) systems to optimally set the thickness and / or other dimensions of the articular surface of the TKA. These adjustable trial tibial pad devices may include a plurality of preset thickness settings, wherein the thickness is a thickness between a femoral articular surface and a tibial seating surface of the adjustable trial tibial pad device.

Description

Priority requirements

[0001] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 492,472, filed March 27, 2023, entitled “DEVICES FOR SETTING POLYETHYLENE THICKNESS DURING TOTALKNEE ARTHROPLASTY”, the entire contents of which are incorporated herein by reference. background

[0002] With the development of total knee arthroplasty (TKA) and the increasing demand for this surgery in hospitals and outpatient clinics, operating room efficiency has become crucial. During primary and revision TKA surgeries, surgeons must determine the thickness of the polyethylene liner to optimally reproduce the knee's movement and balance. The multiple size options for the femoral and tibial components in TKA require a large number of trial tibial articular surfaces available during each surgery. Storing and cleaning these individual liner trial inserts is expensive and space-consuming. Furthermore, changing and trial inserting various polyethylene liner sizes during surgery is a time-consuming and challenging part of the procedure.

[0003] Currently, all major TKA designs consist of a femoral component and a tibial component. Each component is sized to match the patient's anatomy and is fixed to the bone, with a plastic (polyethylene) implant (also known as a tibial liner and / or articular surface) fitting between the femoral and tibial components. This tibial liner (“implant”) typically comes in many different thicknesses and is a component of all modern TKA system designs. This implant is usually made of polyethylene. During the procedure, trial implants of different thicknesses (“trials”) are inserted, tested, and removed to assess knee soft tissue balance and knee joint movement. Once the final thickness is selected, the desired thickness of the final implantable polyethylene is placed and locked to the tibial component according to the manufacturer's design. However, the repeated removal and replacement of trial articular surfaces during the trial stage of TKA adds significant time and complexity to the surgical procedure. What is needed are methods and devices (e.g., devices) that can address these issues. Overview of this disclosure

[0004] This article describes mechanical, self-contained, non-implantable (e.g., inserted and removed during surgery) devices, systems, and methods for setting the thickness of the articular surface during intraoperative trial and balancing in total knee arthroplasty (TKA). For convenience, these devices may be referred to as adjustable trial tibial liners, or simply as adjustable liners. The adjustable trial tibial liners described herein can be used as part of primary or revision TKA to adjust or select the thickness of the tibial liner to determine the optimal thickness of the selected tibial liner (e.g., a polyethylene liner). The ability to adjust the height (thickness) to optimize tibial liner dimensions using a self-contained mechanism (e.g., ratchet, rotary, magnetic, mechanical, etc.) that expands the thickness of the tibial trial liner will overcome many challenges in implant selection and sizing design in TKA. This article describes selectively expandable tibial liners / articular surfaces.

[0005] Existing trial tibial liners are temporary components used in total knee arthroplasty (TKA) to assess stability, range of motion, and soft tissue balance. However, current trial systems typically require a variety of different trial liners of varying sizes, necessitating multiple insertions and removals. Furthermore, recent evidence suggests that trial tibial liners do not accurately reproduce the same joint kinematics as the final liner. The adjustable trial tibial liner described herein provides a single, adjustable trial tibial liner that can be incrementally adjusted by the user (e.g., a physician, surgeon, etc.) after a single insertion, allowing for adjustment of joint distraction in a manner that enables a more realistic comparison with the final implant.

[0006] Typically, the adjustable trial tibial liner and method described herein can be configured to allow a user to easily see the current or selected thickness (e.g., height) of the adjustable trial tibial liner and easily select different thicknesses. Furthermore, the adjustable trial tibial liner described herein is configured to reproduce the mechanical properties of the final implant at each selected thickness. The adjustable trial tibial liner has multiple preset thicknesses (e.g., two or more, three or more, four or more, etc.) corresponding to the final implant to be inserted. Additionally, the adjustable trial tibial liner includes one or more stabilizing features that allow the adjustable trial tibial liner to reproduce the mechanical stability of the implant even at different selectable preset thicknesses. These devices can include features that significantly improve the reliability and effectiveness of the adjustable trial tibial liner, including in tests during the implantation process (e.g., flexion / extension cycles, torsion, and relaxation tests). This is particularly challenging for expandable liners because the effect of forces acting on the implant (e.g., during flexion and extension cycles) can vary with height. The adjustable tibial liner described herein can be configured to provide stability at each selectable preset height.

[0007] In general, this article describes a mechanically adjustable device (e.g., adjustable via ratchet, cam, magnet, electric, or other mechanical techniques) incorporated into an adjustable trial tibial liner. The thickness of the adjustable trial tibial liner can be incrementally increased (e.g., with each “click”, “rotation”, or “movement” of the mechanical device) to a variety of preset thicknesses. These discrete dimensions can be selected to be physiologically relevant and can correspond to the size of the final articular surface liner (implant) to be inserted. This reduces the need for repeated removal of the trial liner and re-insertion of the next thicker or thinner size. Instead, the surgeon can simply adjust the common thicknesses of this self-contained and adjustable trial tibial liner and determine which appropriate tibial articular surface thickness to use for insertion, and then select the final polyethylene liner (implant) for insertion.

[0008] Typically, the device described herein may have an articular side (upper side) that mates with the femur and a component side (lower side) that mates with the tibial component. In this case, modular joint or component adapters (single or two) can be placed on the adjustable unit. Alternatively, the mechanical device can be contained in a fully self-contained mold. Both concepts satisfy the goal of balancing flexion and extension space and balancing the knee joint without having to remove and reinsert multiple components to achieve different component thicknesses.

[0009] In some examples, a mechanical device can be used for each polyethylene component size.

[0010] Typically, the adjustable trial-molded tibial liner described herein is not for prolonged implantation, but rather for acute insertion for sizing design / testing, and can have a modular design to simplify sterilization. The device and method described herein can be used across multiple different TKA implant designs in both initial and revision settings. That is, the adjustable trial-molded tibial liner described herein allows for thickness adjustment and can be fitted or constructed into multiple different polyethylene shapes / models, including different designs, TKA principles, and TKA / polyethylene constraints.

[0011] For example, this article describes an adjustable trial-molded tibial liner device for setting the joint surface thickness during total knee arthroplasty (TKA) or revision surgery. The device includes: a femoral joint plate having a femoral articular surface configured to engage with a femoral component of a TKA system; a tibial plate engagement frame having a tibial placement surface configured to engage with a tibial plate of a TKA system; a distension selector cam having a cam surface having multiple positions including multiple preset distension thicknesses between the femoral articular surface and the tibial placement surface; and a distension input selector coupled to the distension selector cam and configured to be actuated to drive movement of the distension selector cam to change the distension thickness between the femoral articular surface and the tibial placement surface.

[0012] In some cases, an adjustable trial-fit tibial liner device for setting the joint surface thickness during total knee arthroplasty (TKA) or revision surgery includes: a femoral joint plate having a femoral articular surface configured to engage with a femoral component of the TKA system; a tibial plate engagement frame having a tibial placement surface configured to engage with a tibial plate of the TKA system; a spreader selector cam having a cam surface including multiple flat sides on the cam surface, each flat side corresponding to a preset spread thickness between the femoral articular surface and the tibial placement surface; one or more A plurality of spread selector cam driven surfaces configured to support the cam surfaces of the spread selector cam; and a spread input selector coupled to the spread selector cam and configured to be actuated to drive the spread selector cam against the one or more spread selector cam driven surfaces to change the spread thickness between the femoral joint surface and the tibial placement surface; wherein the femoral joint plate and the tibial plate joint frame are connected together via one or more telescopic supports configured to provide lateral support and prevent swaying at each of the preset spread thicknesses corresponding to the plurality of flat sides on the cam surface.

[0013] An adjustable trial-fit tibial liner device for setting the joint surface thickness during total knee arthroplasty (TKA) or revision surgery may include: a femoral joint plate having a femoral articular surface configured to engage with a femoral component of a TKA system; a tibial plate engagement frame having a tibial placement surface configured to engage with a tibial plate of a TKA system; a spreader selector cam having a cam surface including a plurality of flat sides on the cam surface, each flat side corresponding to a preset spread thickness between the femoral articular surface and the tibial placement surface; one or more spreader selector cam driven surfaces configured to support the cam surface of the spreader selector cam; and visualization. A visualization window extending through the anterior region of the femoral plate is configured to allow visualization of a dispersive selector output indicator on a dispersive selector cam, indicating the current dispersive thickness between the femoral articular surface and the tibial placement surface; a dispersive input selector is configured to be actuated to drive movement of the dispersive selector cam to change the current dispersive thickness between the femoral articular surface and the tibial placement surface, wherein the femoral plate and tibial plate engagement frame are joined together via one or more telescopic supports configured to provide lateral support between the femoral articular surface and the tibial placement surface at each of the preset dispersive thicknesses.

[0014] In any of these devices, the cam surface may include a plurality of flat sides, each flat side corresponding to one of a plurality of preset spreading thicknesses between the femoral articular surface and the tibial placement surface.

[0015] Any of these devices may include a visualization window extending through the femoral joint plate, wherein the visualization window is configured to allow visualization of a distraction selector output indicator that indicates the current distraction thickness between the femoral articular surface and the tibial placement surface. The window may be open (uncovered) or covered by a transparent material. In any of these examples, the visualization window is located on the central anterior region of the femoral joint plate.

[0016] In any of these devices, a spreader selector output indicator, located on a spreader selector cam, indicates a preset spread thickness between the femoral joint surface and the tibial placement surface. In some cases, these preset spread thicknesses correspond to thicknesses between 8 mm and 16 mm. For example, the preset spread thicknesses may include at least 9 mm, 11 mm, and 13 mm. In some cases, the preset spread thicknesses may include at least 10 mm, 12 mm, and 14 mm.

[0017] Any of these devices may include one or more selector cam driven surfaces. In some examples, the one or more selector cam driven surfaces may be on the tibial placement surface. The expansion input selector may be on the front region of the device. The femoral joint plate and tibial plate joint frame may be coupled together via one or more telescopic supports configured to provide lateral support and prevent swaying at each of the predetermined expansion thicknesses of the plurality of flat sides corresponding to the cam surfaces between the femoral joint surface and the tibial placement surface. For example, the one or more telescopic supports may include multiple telescopic supports. The one or more telescopic supports may include multiple bilateral telescopic supports.

[0018] Any of these devices may include a rear cam member coupled to a spread selector cam via a spread input selector, wherein activation of the spread input selector alters the distance between the rear cam member and the spread selector cam to change the spread thickness between the femoral articular surface and the tibial placement surface.

[0019] This document also describes methods for using any of these devices, including their use as part of a TKA procedure. For example, a method for determining the joint surface thickness in a total knee arthroplasty (TKA) or revision surgery using an adjustable trial-fit tibial liner device may include: inserting the adjustable trial-fit tibial liner device between the femoral component and tibial plate of the TKA system, wherein the adjustable trial-fit tibial liner is in a first thickness configuration; examining the knee joint response to loads and / or movements corresponding to the first thickness configuration; changing the thickness of the adjustable trial-fit tibial liner device from the first thickness configuration to a preset second thickness configuration; examining the knee joint response to a second load and / or movement corresponding to the preset second thickness configuration; and removing the adjustable trial-fit tibial liner device and selecting the joint surface to be positioned between the femoral component and tibial plate of the TKA system based on the knee joint response to loads and / or movements.

[0020] Any of these methods may include repeating the steps of changing the thickness of the adjustable tibial liner device and checking the knee joint response before removing the adjustable tibial liner. Checking the knee joint response to load and / or movement may include checking the knee joint response to one or more of the following: multiple flexion and extension cycles and torsional / rotational movements. Changing the thickness of the adjustable tibial liner device from a first thickness configuration to a preset second thickness configuration may include activating a spread input selector to drive the spread selector cam to move against one or more spread selector cam driven surfaces to change the spread thickness between the femoral articular surface and the tibial placement surface of the adjustable tibial liner device. Changing the thickness of the adjustable tibial liner device may include rotating the spread selector cam such that one of a plurality of flat sides on the cam surface abuts against the one or more spread selector cam driven surfaces, wherein each of the plurality of flat sides corresponds to a preset spread thickness between the femoral articular surface and the tibial placement surface.

[0021] Any of these methods may include visually observing the spread selector output indicator through a visualization window on the femoral joint surface of an adjustable tibial liner device.

[0022] All methods and apparatuses described herein (in any combination) are conceived herein and can be used to achieve the benefits described herein. Brief description of the attached diagram

[0023] A better understanding of the features and advantages of the methods and apparatus described herein will be obtained by referring to the following detailed description of illustrative embodiments and the accompanying drawings, in which: Figures 1A-1B The illustration shows an example of a total knee arthroplasty (TKA) system that includes a femoral component, a stemmed tibial component (tibial plate), and articular surface implants. Figure 1B The PKA system of claim 1, which is implanted into the knee joint, is shown.

[0024] Figures 2A-2C An example of an adjustable tibial liner device is illustrated schematically. Figure 2A An adjustable tibial liner device is shown. Figures 2B-2C It shows Figure 2A Application of adjustable tibial liner device in tibial components of TKA system.

[0025] Figures 3A-3B They are shown respectively Figures 2A-2C Front (front) perspective view and back (rear) perspective view of the adjustable tibial liner device.

[0026] Figures 4A-4F The illustration is similar to Figures 2A-2C and Figures 3A-3B The adjustable tibial liner device is expanded. Figures 4A-4B A front perspective view and a side view of the adjustable tibial liner device in its most compact configuration (e.g., 10 mm) are shown. Figure 4C and Figure 4D A front perspective view and a side view of an adjustable tibial liner device in a first preset thickness configuration (e.g., 12 mm) are shown. Figure 4E and Figure 4F A front perspective view and a side view of an adjustable trial-molded tibial liner device in a second preset thickness configuration (e.g., 14 mm) are shown, respectively.

[0027] Figures 5A-5C It shows a method similar to Figures 4A-4F The side cross-sectional view of the adjustable tibial liner device shown illustrates the change in the expansion (thickness) of the femoral joint surface of the adjustable tibial liner device relative to the tibial placement surface of the adjustable tibial liner device.

[0028] Figures 6A-6B A second example of the adjustable tibial liner device described herein is illustrated.

[0029] Figures 7A-7B Another example of the adjustable tibial liner device described herein is illustrated schematically. Figure 7A A side perspective view is shown, and Figure 7B A partially transparent view is shown.

[0030] Figures 8A-8F It shows Figures 7A-7B Additional view of the adjustable tibial liner device. Figure 8A A cross section is shown passing through the anterior-posterior axis (midline) of the adjustable tibial liner device. Figure 8B An exploded view is shown. Figure 8C and Figure 8D A bottom perspective view of a portion of the adjustable tibial liner device is shown. Figure 8E A partial exploded view of the adjustable tibial liner device is shown. Figure 8F A cross-section is shown passing through the centerline of the adjustable tibial liner device.

[0031] Figures 9A-9L An example of the adjustable tibial liner device described herein is shown in its spread (e.g., controllable thickness setting). Figure 9A , Figure 9B and Figure 9C The adjustable trial-molded tibial liner device in a first thickness configuration (e.g., a 10 mm gap between the femoral joint surface and the tibial placement surface) is shown in a side perspective view, a side view, and a cross-sectional view. Figure 9D , Figure 9E and Figure 9F The adjustable trial-molded tibial liner device in a second thickness configuration (e.g., a 12 mm gap between the femoral joint surface and the tibial placement surface) is shown in a side perspective view, a side view, and a cross-sectional view. Figure 9G , Figure 9H and Figure 9I An adjustable trial-molded tibial liner device in a third thickness configuration (e.g., a 14 mm gap between the femoral articular surface and the tibial placement surface) is shown in side perspective, side view, and cross-sectional view, respectively. Figure 9J , Figure 9K and Figure 9L The adjustable trial-molded tibial liner device in a fourth thickness configuration (e.g., a 16 mm gap between the femoral joint surface and the tibial placement surface) is shown in a side perspective view, a side view, and a cross-sectional view.

[0032] Figures 10A-10F Another example of the adjustable tibial liner device as described herein is illustrated schematically. Figure 10A A side perspective view is shown. Figure 10B A front view is shown. Figure 10C An exploded view is shown. Figure 10D A front perspective view is shown, and Figures 10E-10F A cross-sectional view is shown passing through the centerline of the adjustable tibial liner device.

[0033] Figure 11 An example of a method for using an adjustable tibial liner device as described herein is illustrated schematically. Detailed description

[0034] This article describes adjustable trial-fit tibial liner devices that can be used with total knee arthroplasty (TKA) systems to optimally set the thickness and / or other dimensions of the joint surfaces in TKA. These devices may include multiple preset thickness settings, where the thickness is the thickness between the femoral joint surface and the tibial placement surface of the adjustable trial-fit tibial liner device.

[0035] A total knee arthroplasty (TKA) system typically consists of a femoral component and a tibial component (e.g., a tibial plate) implanted into the bone. This is in Figure 1A-Figure 1B The diagram shows how each component is secured to the bone, and a plastic (e.g., polyethylene) implant (also known as a tibial liner or articular surface) fits between the femoral and tibial components. Figure 1A-Figure 1B The image shows a total knee implant comprising a femoral component 103, a stemmed tibial plate 105, and a polyethylene tibial liner 101. Figure 1B The connection to the femur 114 and tibia 110 is shown. Figure 1AThe TKA system. For completeness, the patella 116 and fibula 112 are shown. The tibial liner (implant 101) is typically available in multiple thicknesses and is selected by the user (e.g., the surgeon). This component is typically made of polyethylene. During surgery, the user must test trial joint surfaces (“trial molds”) of different thicknesses before selecting the final implant to be inserted. This test is performed by inserting each trial mold individually and assessing the soft tissue balance and knee joint movement. Once the final thickness is selected, the final implant with the desired thickness is placed and locked into the tibial component according to the manufacturer’s design. As mentioned above, the trial molding process may require multiple removals and replacements of trial molds (e.g., trial joint surfaces) and can add significant time and inconvenience to the surgical procedure.

[0036] Typically, adjustable trial-fit tibial liner devices may include mechanical actuators and can be positioned between the joint side and the component side of the tibial liner. The thickness of the liner can be selected by the user (e.g., a physician) to determine the appropriate size for the joint surface to be implanted.

[0037] In any of these devices, an adjustable trial-fit tibial liner device can be configured to set the articular surface thickness during TKA or revision surgery. These devices can be modular, including a femoral plate that can move relative to a tibial plate engagement frame between preset positions (or, less ideally, in some cases, consecutive positions). The femoral plate may include a femoral articular surface configured to engage with the femoral component of the TKA system. The tibial plate engagement frame may have a tibial placement surface configured to engage with the tibial plate of the TKA system. These upper and lower surfaces of the device can be configured to match the general contour of an articular surface implant 101 (e.g., a polyethylene implant) that will be more permanently implanted between the femoral component and the tibial plate of the TKA.

[0038] Typically, these devices may include a spreader mechanism configured to alter the distance (thickness) between the femoral articular surface and the tibial placement surface. For example, any of these devices may include a spreader selector cam having one or more cam surfaces. Movement of the spreader selector cam can drive the cam surfaces against a driven surface (e.g., a spreader selector cam follower) to increase the spacing between the femoral articular surface and the tibial placement surface. Typically, the cam surfaces may have multiple positions, each corresponding to a preset spread thickness between the femoral articular surface and the tibial placement surface. The spreader selector may be moved and its position selected by a spreader input selector coupled to the spreader selector cam and configured to be actuated to drive movement of the spreader selector cam to alter the spread thickness between the femoral articular surface and the tibial placement surface.

[0039] Any of these devices may also include an output indicating the dislocation status (e.g., thickness) of the device. For example, any of these devices may include a visualization window showing an indicator of the current thickness. In some cases, the visualization window may be positioned, for example, through the anterior region of the femoral plate, such that the visualization window allows visualization of the indicator. The location of the window on the anterior region of the femoral plate may be particularly helpful, as it does not interfere with the contact between the femoral components and is visible for most of the surgical period. The window may allow observation of a marker, which in some cases may be a dislocation selector output indicator, which may be located on the dislocation selector cam and may indicate the current dislocation thickness between the femoral articular surface and the tibial placement surface.

[0040] Any of these devices may also include a displacement input selector configured to be actuated to drive movement of a displacement selector cam to change the current displacement thickness between the femoral articular surface and the tibial placement surface. The displacement input selector may be configured as a mechanical selector, such as (but not limited to) a screw, key, lever, etc. In some cases, the displacement input selector may be manually operated using tools such as screwdrivers, wrenches, etc.

[0041] The femoral plate and tibial plate joint frame can typically be joined together via one or more telescopic supports that allow for stable separation. In some cases, the telescopic supports are configured to provide lateral support between the femoral articular surface and the tibial placement surface at each predetermined expansion thickness. For example, the telescopic supports can be positioned bilaterally on either side of the device's midline. The walls of the telescopic supports can mate with the support walls they telescopically extend into and out of with relatively tight tolerances (e.g., less than 0.8 mm, less than 0.5 mm, less than 0.3 mm, less than 0.2 mm, less than 0.1 mm, etc.). In some cases, the device (part of or alone of the telescopic supports) may include one or more biasing elements (e.g., springs, compressible materials, etc.) that can suppress or prevent instability. In some cases, the device may include one or more lateral supports to prevent torsional instability.

[0042] Figures 2A-2C An example of an adjustable tibial liner device is schematically illustrated. For example, Figure 2AAn adjustable trial-molded tibial liner device is shown, comprising a femoral joint plate 211 having a femoral articular surface 213 configured to engage with a femoral component of a TKA system. The adjustable trial-molded tibial liner device 200 also includes a tibial plate engagement frame 221 having a tibial placement surface 222 configured to engage with a tibial plate of a TKA system. Figures 2A-2C The adjustable tibial liner device shown also includes a spreader selector cam 217 with a cam surface 267, the spreader selector cam having multiple flat sides on the cam surface, each flat side corresponding to a preset spread thickness between the femoral joint surface and the tibial placement surface. Figure 2A In this example, the expansion selector cam is visible through visualization window 215, and the cam also includes an expansion selector output indicator 277, which is shown as a digital indicator of thickness (e.g., 10mm, 12mm, 14mm, etc.) in this example. Typically, adjustable tibial liner devices can be configured to have any suitable thickness, for example, between 8mm and 20mm (including any increments therebetween, such as, but not limited to: 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc.). Any number of thickness settings can be used; in Figures 2A-2C , Figures 3A-3B and Figures 4A-4F The image shows three thickness settings (10mm, 12mm and 14mm).

[0043] therefore, Figures 2A-2C The adjustable trial molding tibial liner device includes a distension input selector configured to be actuated by rotation (e.g., using a driver tool, not shown) to drive the movement of a distension selector cam to change the current distension thickness between the femoral articular surface and the tibial placement surface. Figures 2A-2B The illustration shows the process before placement on the stemmed tibial plate 105. Figure 2B ) and afterwards ( Figure 2C )of Figure 2A The same adjustable tibial liner device 200. Figures 2A-2C In the diagram, the adjustable tibial liner device is shown with a minimum thickness of 230 mm, for example, 10 mm. (As will be...) Figures 4A-4F and Figures 5A-5C As shown, this thickness can be changed.

[0044] Figures 3A-3B and Figures 4A-4F The illustration is similar to Figures 2A-2CThe adjustable tibial liner device shown is illustrated. Similar numerals are used in the illustrations provided herein to denote elements with the same basic functional characteristics, but different constructions and variations may be used. For example, Figures 3A-3B They are shown respectively Figures 2A-2C Front (anterior) perspective view and back (rear) perspective view of the adjustable trial molding tibial liner device. Figure 3A In the femoral joint plate 211, which has a femoral articular surface 213 on its upper (outer) surface, a visualization window 215 region is cut through the femoral articular surface 213. The adjustable tibial liner device also includes a spreader selector cam 217, which includes a cam surface 267. In this example, the cam surface is divided into two surfaces on a portion of the cam circumference, both of which are configured to engage with the spreader selector cam driven surfaces 227, 227', which are configured to support the cam surface of the spreader selector cam. The spreader selector cam 217 is configured to be activated by rotating a spreader input selector 219. In this example, the spreader input selector is shown as a keyed pin that can engage with the cam 217 and drive (one or more) cam surfaces against the driven surfaces 227, 227' to change the spacing between the femoral joint plate 211 and the tibial plate joint frame 221.

[0045] As mentioned, the visualization window 215 extends through the anterior region of the femoral joint plate 211, wherein the visualization window is configured to allow visualization of the markings on the expansion selector output indicator 277 on the expansion selector cam 217, which indicate the current thickness between the femoral joint surface and the tibial placement surface.

[0046] Figures 3A-3B A pair of telescopic support regions 241, 241' (telescopic supports) are also shown, arranged bilaterally on both sides of the adjustable tibial liner device. In this example, the femoral plate and tibial plate engagement frame are connected via these telescopic supports, such that when the spacing between the femoral plate and tibial plate engagement frame changes (by moving the spreader selector cam), the telescopic supports 241, 241' extend and / or retract relative to the telescopic support receiver regions (receivers) 225, 225'. This can provide lateral support between the femoral articular surface and the tibial placement surface at each preset spread thickness. In this example, the telescopic supports are formed as part of the femoral plate, and the receivers are part of the tibial plate engagement frame 221; however, this arrangement can be reversed. The receivers include support walls 246, 246' for supporting the telescopic support receivers. The receivers can be asymmetrical in shape, which can increase lateral support.

[0047] Figures 4A-4FThe illustration is similar to Figures 2A-2C and Figures 3A-3B The adjustable tibial liner device is expanded. For example, Figures 4A-4B A front perspective view and a side view of the adjustable tibial liner device in its most compact configuration (e.g., 10 mm) are shown. A spreader selector output indicator 277 is printed on the spreader selector cam 217 and is visible through a window passing through the femoral joint plate. Figure 4A and Figure 4B In the diagram, the expanded input selector 219 is shown with a notched bonding area at the 12 o'clock position. The expanded selector cam has three cam surface areas that are relatively flat and connected by curved areas. Figures 4A-4B In the process, the flat area of ​​the cam surface 267' engages with the cam follower 227, and the distance between the top surface and the bottom surface (e.g., the femoral joint surface and the tibial placement surface) is 10 mm.

[0048] Figure 4C and Figure 4D A front perspective view and a side view of an adjustable trial-molded tibial liner device in a first preset thickness configuration (e.g., 12 mm) are shown. In this example, the expansion input selector 219 is in the 3 o'clock position, and the eccentric outer cam surface has been rotated to a second stable position in which the relatively flat second region engages with the follower. In this case, the distance between the top and bottom surfaces is 12 mm.

[0049] Figure 4E and Figure 4F A front perspective view and a side view of the adjustable tibial liner device in a second preset thickness configuration (e.g., 14 mm) are shown. The input selector 219 is extended to the 6 o'clock position, and the eccentric outer cam surface has been rotated to a third stable position, in which the relatively flat third region engages with the cam follower. In this case, the gap between the top and bottom surfaces is 14 mm. Figure 5A Figure 5C illustrates a method similar to... Figures 4A-4F The side cross-sectional view of the adjustable tibial liner device shown illustrates the change in the expansion (thickness) of the femoral articular surface of the femoral joint plate 211 relative to the tibial plate joint frame 221. Figure 5A The interval is 10mm, in Figure 5B The spacing is 12mm, and in Figure 5C The spacing is 14mm.

[0050] Figures 6A-6B A second example of the adjustable tibial liner device 600 described herein is shown. This configuration is similar to... Figures 2A-2C , Figures 3A-3B , Figures 4A-4F and Figures 5A-5C The configuration shown is such that the selector cams 217', 217'' are arranged along the long axis (e.g., transverse to the anterior-posterior axis) of the adjustable trial-molded tibial liner device. The adjustable trial-molded tibial liner device also includes a femoral plate 211 and a tibial plate engagement frame 221. The femoral plate 211 has a femoral articular surface 213 configured to engage with the femoral component of the TKA system, and the tibial plate engagement frame 221 has a tibial placement surface configured to engage with the tibial plate of the TKA system. In this example, cam 217'' can be rotated (e.g., 90 degrees 217'') to increase the spacing between the femoral articular surface and the tibial placement surface, for example, 2 mm. Figure 6A A device with a thickness of 10 mm is shown, and Figure 6B A device with a thickness of 12 mm is shown.

[0051] Figures 7A-7B Another example of the adjustable tibial liner device described herein is illustrated schematically. Figure 7A A side perspective view is shown, and Figure 7B A partially transparent view is shown. In this example, a pair of cam elements, one at the front and one at the rear, can be used to change the spacing between the femoral articular surface and the tibial placement surface; the relative spacing between the front spreader selector cam 217 and the rear cam member (rear cam) 866 can be changed using a spreader input selector (such as those shown above and / or threaded spreader input selectors). The device may include additional cam follower surfaces, such as... Figure 7B and Figures 8A-8F As shown. In Figures 7A-7B In this example, the adjustable tibial liner device includes a tibial plate joining frame 221 and a femoral joining frame 211, as well as an anterior expander cam 217 and a posterior cam 866. In this example, both the tibial plate joining frame 221 and the femoral joining plate 211 include driven surfaces, such as an expander selector cam follower 227 and a posterior cam follower 889.

[0052] Figures 8A-8F It shows Figures 7A-7B Additional view of the adjustable tibial liner device. Figure 8A A cross section is shown passing through the anterior-posterior axis (midline) of the adjustable tibial liner device. Figure 8B An exploded view is shown. Figure 8C and Figure 8D A bottom perspective view of a portion of the adjustable tibial liner device is shown. Figure 8E A partial exploded view of the adjustable tibial liner device is shown. Figure 8F A cross-section is shown passing through the centerline of the adjustable tibial liner device.

[0053] Figures 9A to 9L It shows Figures 7A-7B and Figures 8A-8F The adjustable tibial liner device described herein expands (e.g., its thickness can be controllably set). For example, Figure 9A , Figure 9B and Figure 9C The adjustable trial-molded tibial liner device in a first thickness configuration (e.g., a 10 mm gap between the femoral joint surface and the tibial placement surface) is shown in a side perspective view, a side view, and a cross-sectional view. Figure 9D , Figure 9E and Figure 9F The adjustable trial-molded tibial liner device in a second thickness configuration (e.g., a 12 mm gap between the femoral joint surface and the tibial placement surface) is shown in a side perspective view, a side view, and a cross-sectional view. Figure 9G , Figure 9H and Figure 9I An adjustable trial-molded tibial liner device in a third thickness configuration (e.g., a 14 mm gap between the femoral articular surface and the tibial placement surface) is shown in side perspective, side view, and cross-sectional view, respectively. Figure 9J , Figure 9K and Figure 9L An adjustable trial-molded tibial liner device in a fourth thickness configuration (e.g., a 16 mm gap between the femoral articular surface and the tibial placement surface) is shown in a side perspective view, side view, and cross-sectional view, respectively. Figures 9A-9L In this configuration, when the expansion input selector is actuated, the expansion selector cam (e.g., the front expansion selector cam) and the rear expansion selector cam move relative to each other to change the spacing between the top and bottom of the adjustable tibial liner device. Therefore, the expansion input selector (for simplicity, Figure 9A-9L (Not shown in the image) Activation changes the distance between the rear cam member and the (front) spread selector cam to change the spread thickness between the femoral joint surface and the tibial placement surface.

[0054] Figures 10A-10F A schematic illustration of a diagram similar to those described herein. Figures 7A-7B , Figures 8A-8F and Figures 9A-9L Another example of the adjustable tibial liner device shown. Figure 10A A side perspective view of the device is shown. The device also includes a femoral plate 211 and a tibial plate engagement frame 221. The femoral plate 211 has a femoral articular surface configured to engage with the femoral component of a TKA system, and the tibial plate engagement frame 221 has a tibial placement surface configured to engage with the tibial plate of a TKA system. The device also includes a spreader selector cam (shown as front cam 217) and a spreader input selector 219, as well as a rear cam 866. Figure 10BAs shown, the device is configured to have five expansion settings (e.g., 10mm, 12mm, 14mm, 16mm, and 18mm). Therefore, the expansion input selector can be configured to switch between these five states. Figure 10C An exploded view of the device is shown. It includes a spread-out input selector configured as a threaded screw 219. The cam surface 267 of the spread-out selector cam 217 has a dovetail configuration. Figure 10D It shows Figures 10A-10C Front perspective view of the assembly equipment. Figures 10E-10F A cross-sectional view through the midline of the adjustable tibial liner device is shown, illustrating the operation of this example. Figure 10E In this case, the threaded, open input selector is retracted, and the device has its minimum thickness (e.g., 10 mm). Figure 10F In this process, the input selector 219 is pushed forward (e.g., by rotating the screw-like body) to separate the femoral joint plate 211 from the tibial plate joint frame 221 (e.g., with an 18 mm gap).

[0055] In use, the device can be configured as part of a TKI procedure as described above. For example, Figure 11 This illustration schematically depicts an example of a method using an adjustable trial-molded tibial liner device as described herein as part of a TKI procedure. Figure 11In this method, the approach can be used to determine the joint surface thickness for total knee arthroplasty (TKA) or revision surgery. An adjustable trial-molded tibial liner device can be inserted after the TKA system has been attached to the patient 1101. For example, the adjustable trial-molded tibial liner device as described herein can be inserted between the femoral component and the tibial plate of the TKA system, wherein the adjustable trial-molded tibial liner is in a first thickness configuration. Once the adjustable trial-molded tibial liner device is placed on the tibial plate of the TKA system, it can then be iteratively adjusted to different thicknesses, and the user examines the knee joint to determine the optimal thickness of the implant to replace the adjustable trial-molded tibial liner device. For example, the user can use the adjustable trial-molded tibial liner device in the first thickness configuration to examine the knee joint's response to load and / or movement 1103. The user can then change the thickness of the adjustable trial-molded tibial liner device from the first thickness configuration to a preset second thickness configuration 1105 and examine the knee joint's response to the second thickness. Users can test the knee joint's response using various tests, including loading / unloading the knee joint and / or multiple flexion and extension cycles and / or twisting / torsional movements. The knee joint can be tested 1107 after each thickness change. This process can be repeated 1109 as needed until the user determines which thickness is optimal. After this, the user can remove the adjustable trial-molded tibial liner device 1111. The articular surface to be positioned between the femoral component and the tibial plate of the TKA system can then be selected and inserted based on the knee joint's response to load and / or movement at different test thicknesses.

[0056] In any of these methods, after adjusting the height, additional stabilizing elements can be applied, for example, at least partially, around the perimeter of the device. For instance, an external U-shaped member can engage around the perimeter of the device at various points or at each thickness, which can enhance stability. This U-shaped member can be releasably engaged with the sides of the device.

[0057] These devices can be easily disassembled for cleaning and sterilization purposes. In all designs, the base or lower part of the structure will be properly locked within the tibial component, and will have an upper part with an articular geometry that matches the femoral component.

[0058] All publications and patent applications mentioned in this specification are incorporated herein by reference in their entirety, to the extent that each individual publication or patent application is specifically and individually indicated to be incorporated by reference. Furthermore, it should be understood that all combinations of the foregoing concepts and other concepts discussed in more detail below (provided these concepts are not inconsistent with each other) are considered part of the inventive subject matter disclosed herein and can be used to achieve the benefits described herein.

[0059] When a feature or element is described herein as being “on” another feature or element, the feature or element may be directly on the other feature or element, or there may be intermediate features and / or elements present. Conversely, when a feature or element is described as being “directly on” another feature or element, no intermediate features or elements are present. It should also be understood that when a feature or element is described as being “connected,” “attached,” or “joined” to another feature or element, the feature or element may be directly connected, attached, or joined to the other feature or element, or there may be intermediate features or elements present. Conversely, when a feature or element is described as being “directly connected,” “directly attached,” or “directly joined” to another feature or element, no intermediate features or elements are present. Although described or shown with respect to one embodiment, the features and elements thus described or shown can be applied to other embodiments. Those skilled in the art will also understand that references to structures or features set “adjacent” to another feature may have portions overlapping with or below that adjacent feature.

[0060] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein are intended to also include the plural forms. It should also be understood that the terms “comprises” and / or “comprising” as used in this specification specify the presence of stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “ / ”.

[0061] Spatial terms such as “under,” “below,” “lower,” “over,” and “upper” may be used herein for convenience of description to describe the relationship of one element or feature, as shown in the accompanying drawings, to one or more other elements or features. It should be understood that spatially related terms are intended to include different orientations of the device in use or operation, in addition to those depicted in the accompanying drawings. For example, if the device in the accompanying drawings is reversed, an element described as “below” or “beneath” would then be oriented “over”. Thus, the exemplary term “under” can encompass both “over” and “below” orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise), and the spatially related descriptive terms used herein are interpreted accordingly. Similarly, unless otherwise specified, the terms “upwardly,” “downwardly,” “vertical,” and “horizontal” are used in this document for illustrative purposes only.

[0062] While the terms "first" and "second" may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms unless the context otherwise requires. These terms may be used to distinguish one feature / element from another. Therefore, the first feature / element discussed below may be referred to as the second feature / element, and similarly, the second feature / element discussed below may be referred to as the first feature / element, without departing from the teachings of the invention.

[0063] Generally, any apparatus and method described herein should be understood as inclusive, but all or a subset of components and / or steps may optionally be exclusive and may be expressed as “consisting of various components, steps, sub-components or sub-steps” or alternatively “consisting substantially of various components, steps, sub-components or sub-steps”.

[0064] As used herein in the specification and claims, including in the examples, and unless otherwise expressly stated, all figures may be understood as if they begin with the words “about” or “approximately,” even if the term is not explicitly stated. The phrase “about” or “approximately” may be used when describing magnitude and / or location to indicate that the described value and / or location is within a reasonably expected range of value and / or location. For example, numerical values ​​may have values ​​of + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical value given herein should also be understood to include about or approximately that value, unless the context otherwise requires. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Any numerical ranges listed herein are intended to include all subranges contained therein. It should also be understood that when a value is disclosed, "less than or equal to" that value, "greater than or equal to" that value, and possible ranges between these values ​​are also disclosed, as would be appropriately understood by a person skilled in the art. For example, if the value "X" is disclosed, then "less than or equal to X" and "greater than or equal to X" (e.g., where X is a numerical value) are also disclosed. It should also be understood that throughout the application, data is provided in a variety of different formats, and this data represents the endpoints and starting points and ranges of any combination of data points. For example, if specific data point "10" and specific data point "15" are disclosed, it should be understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15, as well as ranges between 10 and 15, are considered disclosed. It should also be understood that each unit between two specific units is also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0065] While various illustrative embodiments have been described above, any of several changes may be made to these embodiments without departing from the scope of the invention as described in the claims. Optional features of various apparatus and system embodiments may be included in some embodiments but not in others. Therefore, the foregoing description is provided primarily for illustrative purposes and should not be construed as limiting the scope of the invention as set forth in the claims.

[0066] The examples and illustrations included herein are shown by way of illustration, not limitation, of specific embodiments in which the subject matter can be practiced. As mentioned, other embodiments can be utilized and derived therefrom, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure. For convenience only, such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term "invention," and if more than one is actually disclosed, it is not intended to actively limit the scope of this application to any single invention or inventive concept. Thus, while particular embodiments have been illustrated and described herein, any arrangement considered to achieve the same purpose may replace the particular embodiments shown. This disclosure is intended to cover any and all modifications or variations of the various embodiments. Upon reading the above description, those skilled in the art will understand the combinations of the above embodiments and other embodiments not specifically described herein.

Claims

1. An adjustable trial tibial liner device for setting the joint surface thickness during total knee arthroplasty (TKA) or revision surgery, the device comprising: A femoral articular plate having a femoral articular surface configured to engage with a femoral component of a TKA system. A tibial plate engagement frame having a tibial placement surface configured to engage with the tibial plate of the TKA system; A spreading selector cam has a cam surface having multiple positions, the multiple positions including multiple preset spreading thicknesses between the femoral joint surface and the tibial placement surface; and A spread input selector is coupled to the spread selector cam and configured to be actuated to drive the spread selector cam to move against each other to change the spread thickness between the femoral joint surface and the tibial placement surface.

2. The device according to claim 1, wherein, The cam surface includes multiple flat sides, each flat side corresponding to one of the multiple preset spreading thicknesses between the femoral joint surface and the tibial placement surface.

3. The device of claim 1, further comprising a visualization window through the femoral joint plate, wherein the visualization window is configured to allow visualization of a spread selector output indicator indicating the current spread thickness between the femoral joint surface and the tibial placement surface.

4. The device of claim 3, wherein the visualization window is located on the central anterior region of the femoral joint plate.

5. The device according to claim 3, wherein, The expansion selector output indicator on the expansion selector cam indicates the preset expansion thickness between the femoral joint surface and the tibial placement surface.

6. The device according to claim 1, wherein, The multiple preset expansion thicknesses correspond to thicknesses between 8mm and 16mm.

7. The device according to claim 1, wherein, The preset expansion thicknesses include at least 9mm, 11mm, and 13mm.

8. The device according to claim 1, wherein, The multiple preset expansion thicknesses include at least 10mm, 12mm and 14mm.

9. The device of claim 1, further comprising one or more selector cam driven surfaces.

10. The device according to claim 9, wherein, The one or more selector cam driven surfaces are located on the tibial placement surface.

11. The device according to claim 1, wherein, The expandable input selector is located on the front area of ​​the device.

12. The device according to claim 1, wherein, The femoral joint plate and the tibial plate joint frame are connected together via one or more telescopic supports, each of which is configured to provide lateral support and prevent swaying at each of the predetermined spread thicknesses corresponding to the plurality of flat sides on the cam surface between the femoral joint surface and the tibial placement surface.

13. The device according to claim 12, wherein, The one or more telescopic supports include multiple telescopic supports.

14. The device according to claim 12, wherein, The one or more telescopic supports include multiple double-sided telescopic supports.

15. The device of claim 12, further comprising a rear cam member coupled to the cam of the expander selector via the expander input selector, wherein, Activation of the spread input selector alters the distance between the rear cam member and the spread selector cam, thereby changing the spread thickness between the femoral joint surface and the tibial placement surface.

16. An adjustable trial tibial liner device for setting the joint surface thickness during total knee arthroplasty (TKA) or revision surgery, the device comprising: A femoral articular plate having a femoral articular surface configured to engage with a femoral component of a TKA system. A tibial plate engagement frame having a tibial placement surface configured to engage with the tibial plate of the TKA system; A spreader selector cam having a cam surface, the spreader selector cam including a plurality of flat sides on the cam surface, each flat side corresponding to a preset spreader thickness between the femoral joint surface and the tibial placement surface; One or more extend selector cam driven surfaces configured to support the cam surface of the extend selector cam; and A spread input selector, the spread input selector being coupled to the spread selector cam and configured to be actuated to drive the spread selector cam to move against the one or more spread selector cam driven surfaces to change the spread thickness between the femoral joint surface and the tibial placement surface; The femoral plate and the tibial plate joint frame are connected together via one or more telescopic supports, which are configured to provide lateral support and prevent swaying at each of the predetermined spread thicknesses corresponding to the plurality of flat sides on the cam surface.

17. An adjustable trial tibial liner device for setting the joint surface thickness during total knee arthroplasty (TKA) or revision surgery, the device comprising: A femoral articular plate having a femoral articular surface configured to engage with a femoral component of a TKA system. A tibial plate engagement frame having a tibial placement surface configured to engage with the tibial plate of the TKA system; A spreader selector cam having a cam surface, the spreader selector cam including a plurality of flat sides on the cam surface, each flat side corresponding to a preset spreader thickness between the femoral joint surface and the tibial placement surface; One or more extend selector cam driven surfaces configured to support the cam surface of the extend selector cam; A visualization window extending through the anterior region of the femoral joint plate, wherein the visualization window is configured to allow visualization of a spreader selector output indicator on the spreader selector cam, the spreader selector output indicator indicating the current spread thickness between the femoral joint surface and the tibial placement surface; A displacement input selector is configured to be actuated to drive movement of a displacement selector cam to change the current displacement thickness between the femoral articular surface and the tibial placement surface. The femoral joint plate and the tibial plate joint frame are connected together via one or more telescopic supports configured to provide lateral support between the femoral joint surface and the tibial placement surface at each of the predetermined spread thicknesses.

18. A method for determining the joint surface thickness for total knee arthroplasty (TKA) or revision surgery using an adjustable trial-fit tibial pad device, the method comprising: An adjustable tibial liner device is inserted between the femoral component and the tibial plate of the TKA system, wherein the adjustable tibial liner is in a first thickness configuration. Examine the knee joint's response to loads and / or movements corresponding to the first thickness configuration; The thickness of the adjustable tibial liner device is changed from the first thickness configuration to a preset second thickness configuration; Examine the response of the knee joint to a second load and / or movement corresponding to the preset second thickness configuration; and Remove the adjustable tibial liner device and select the articular surface to be positioned between the femoral component and the tibial plate of the TKA system based on the knee joint’s response to the load and / or movement.

19. The method of claim 18, further comprising the steps of repeatedly changing the thickness of the adjustable tibial liner device and checking the response of the knee joint before removing the adjustable tibial liner.

20. The method according to claim 18, wherein, Examining the knee joint’s response to the load and / or movement includes examining the knee joint’s response to one or more of the following: multiple flexion and extension cycles and twisting / torsional movements.

21. The method according to claim 18, wherein, Changing the thickness of the adjustable tibial liner device from the first thickness configuration to the preset second thickness configuration includes: activating the expansion input selector to drive the expansion selector cam to move against one or more expansion selector cam driven surfaces, thereby changing the expansion thickness between the femoral joint surface and the tibial placement surface of the adjustable tibial liner device.

22. The method of claim 21, wherein changing the thickness of the adjustable posterior tibial liner device comprises: Rotate the spreader selector cam such that one of the plurality of flat sides on the cam surface abuts against the one or more spreader selector cam driven surfaces, wherein each of the plurality of flat sides corresponds to a preset spread thickness between the femoral joint surface and the tibial placement surface.

23. The method of claim 18, further comprising visually observing the spread selector output indicator through a visualization window on the femoral joint surface of the adjustable tibial liner device.

Images