An apparatus and method for preparing the knee joint bone surface for use in artificial knee joint components.

Abstract

A device for minimizing the amount of bone initially required to be resected from the surface of a knee joint, the device being prepared using a plurality of user-operable, adjustable extension tabs that define a stability gap derived from gap measurements taken in each of extension, mid-flexion, and flexion, wherein the stability gap is commensurate with a reference plane derived from the device, wherein final bone resection with corresponding bone surfaces utilizing the reference plane provides optimally balanced angular motion between the tibial and femoral components of a post-operative artificial knee joint.

Description

Technical Field

[0001] The present invention relates to an improved device and method for preparing the proximal surface of the tibia and / or distal femur and the proximal surface of the posterior femoral condyle for an artificial knee joint component. More specifically, the present invention relates to minimizing the amount of bone that needs to be removed from these surfaces initially in the preparation of the artificial knee joint component. Background Art

[0002] As disclosed in WO2016 / 065396 and WO2017 / 181216, the applicant recognized the importance of establishing a "tibial reference plane" defined by the orientation of the inferior side of the joint liner, wherein the tibial reference plane provides the necessary surface contour when replicating the final bone resection as the proximal surface of the tibia, which optimizes the desired balance and stability between the tibial component and the femoral component of the artificial knee joint.

[0003] The ability to achieve this advantageous contouring of the top surface of the tibia by using a "tibial reference plane" relies on the device utilizing an adjustable tibial preparation plate. Such an adjustable tibial preparation plate includes operable height-adjustable extension tabs that facilitate establishing the tibial reference plane by engaging these user-operable height-adjustable extension tabs with the underside of the joint liner.

[0004] While applicant's previous invention was advantageous through the use of a tibial preparation plate and by defining a "tibial reference plane" in particular by an operable height-adjustable extension tab, a problem arose because in order to accommodate the joint liner and tibial preparation plate this meant that additional spacing was required between the ends of the tibia and femur so that these components could be inserted therein.

[0005] It is preferred for the surgeon to minimize the amount of bone that needs to be initially cut away from the end of the tibia, and therefore it is still desirable to take advantage of the benefit of establishing a "tibial reference plane" that can be achieved through the use of the operable, height-adjustable extension tabs enclosed in the applicant's earlier invented tibial preparation plate, but to achieve this result without unnecessarily initially resecting more tibial surface than would otherwise be required.

[0006] Furthermore, the applicant was previously able to provide, through WO2017197462, a method and apparatus for balancing the femoral side of an artificial knee joint, thereby optimizing the final bone resection of the distal femoral and posterior femoral condyle and other femoral cuts to accommodate the femoral component.

[0007] As discussed in WO2017197462, the unique application of a generally L-shaped femoral-tibial stability gap alignment fixture provides a vertical arm with associated lateral extension tabs (which are responsible for providing the necessary distal femoral reference planes by engagement with the anterior plate) and a horizontal arm with associated height extension tabs, which make the necessary adjustments to the base plate (and / or separate portions of the base plate) to establish the necessary posterior condylar reference planes so that if a final resection is made to each of the distal femur and posterior femoral condyles, thereby exposing surfaces having the same contours of these reference planes, this then allows the femoral component of the artificial knee joint to operate in an optimal manner.

[0008] Although applicant's prior invention defined the required reference plane by means of an operable height-extending tab on the horizontal arm and a laterally-extending tab on the vertical arm through the use of a generally L-shaped femoral-tibial stability gap alignment jig, a problem arose because in order to accommodate a conventional anterior plate or standard femoral component and the generally L-shaped femoral-tibial stability gap alignment jig, this meant that additional spacing was required between the ends of the tibia and femur so that both of these components could be inserted therein.

[0009] Again, it is preferred for the surgeon to minimize the amount of bone that needs to be initially resected from the end of the femoral surface, and thus it is still desirable to take advantage of the benefits of establishing a "femoral reference plane" which can be achieved through the use of the operable height-adjustable extension tabs and lateral extension tabs that are part of the applicant's earlier invention of a generally L-shaped femoral-tibial stability gap alignment fixture, but to achieve this result without unnecessarily initially resecting more of the surface of the end of the femoral surface than would otherwise be required.

[0010] It remains, therefore, an object of the present invention to provide a device and method for establishing a tibial reference plane utilizing an operable, height-adjustable extension tab, but to do so by minimizing the spacing required between the ends of the tibia and femur to accommodate the necessary components, thereby establishing the reference plane and thereby minimizing the depth that needs to be cut away from the proximal surface of the tibia during the initial resection as part of the procedure.

[0011] It is therefore another object of the present invention to still provide a device and method for establishing a femoral reference plane utilizing an operable height adjustable extension tab and a laterally adjustable extension tab, but to do so by minimizing the spacing required between the tibial end and the tibial end to accommodate the necessary components, thereby establishing a reference plane and thereby minimizing the depth that needs to be resected from the end of the femoral surface during the initial resection as part of the procedure.

[0012] Other objects and advantages of the present invention will become apparent from a complete reading of the following specification. Summary of the invention

[0013] In one form of the invention, there is provided an apparatus for preparing a proximal tibial surface of a tibial component for an artificial knee joint, the apparatus comprising:

[0014] A joint pad, the joint pad comprising an upper joint surface for engaging a femoral component of a knee joint, the joint pad also comprising a plurality of user-operable height-adjustable extension tabs, wherein the plurality of user-operable height-adjustable extension tabs are height-adjustable from an underside of the joint pad, such that height adjustment of the plurality of user-operable height-adjustable extension tabs defines a stability gap derived from gap measurements taken in each of extension, mid-flexion and flexion, wherein the stability gap is commensurate with a tibial reference plane defined on an underside surface of the joint pad, wherein final bone resection of the proximal surface of the tibia consistent with the tibial reference plane provides balanced angular motion between the tibial component and the femoral component of the artificial knee joint throughout an arc of motion from extension, mid-flexion and flexion.

[0015] An advantage of this arrangement is that since the user-operable height-adjustable extension tabs are located on the underside of the joint pad, there is no need for a separate additional preparation plate that previously included the height-adjustable extension tabs.

[0016] The elimination of a separate preparation plate including height-adjustable extension tabs means that the spacing required for the assembly to properly prepare the proximal tibial surface by establishing a "tibial reference plane" can be reduced, thereby minimizing the depth or amount of bone the surgeon initially needs to remove from the end of the tibia.

[0017] As previously disclosed in patents WO2016 / 065396 and WO2017 / 181216, a tibial and femoral stability gap preparation plate including a user-operable height-adjustable extension tab is adapted to rest on the initially resected proximal tibial surface, but advantageously, the present invention eliminates the preparation plate, yet the desired definable reference plane can still be used because the unique user-operable height-adjustable extension tab (when adjusted in height to create a reference plane) extends directly from the underside of the joint pad to engage the surface of the initially resected tibia, or optionally in other embodiments, if desired, a very thin plate, membrane or the like, may be placed on the initially resected proximal tibial surface, which can prevent compression holes caused by the height-adjustable extension tab pushing down on the initially resected tibial surface during adjustment.

[0018] In the case where the surgeon removes too much tibia for the initial resection of the tibial surface, a shim or the like may be placed on the surface of the initial resection surface of the tibia. The height of the shim may also be adjustable if desired.

[0019] Preferably, the joint pad includes pressure sensor means.Preferably, the pressure sensor means is included in the body of the joint pad, or a series of sensors are included in a user operable height adjustable extension tab.

[0020] Preferably, the device is in communication with a controller to record, calculate and / or display pressure measurements derived from the pressure sensor device.

[0021] Preferably, the device comprises a display unit to visually display the knee joint and the associated tibia and femur thereon.

[0022] Preferably, the display unit comprises functionality for 3D modeling of the knee joint, femur and tibia on the visual display unit.

[0023] Preferably, the joint pad comprises a plurality of slots on an underside of the joint pad, into which corresponding user-operable height-adjustable extension tabs may be enclosed or at least substantially enclosed.

[0024] Advantageously, in this preferred embodiment, further space savings and thereby further minimization of the initial tibial resection can be achieved because the starting point for height adjustability is such that the underside bottom surface of the joint pad simply rests on this initially resected tibial top surface, meaning that when a plurality of user-operable height adjustable extension tabs extend from the underside of the joint pad, such extensions of the tabs are from a flush starting point originating from the bottom surface of the underside of the joint pad.

[0025] Preferably, the plurality of user-operable height adjustable extension tabs comprises three operable height adjustable extension tabs, and wherein the joint pad comprises three corresponding slots, wherein each respective slot of the joint pad surrounds a corresponding user-operable height adjustable extension tab.

[0026] Preferably, each user-operable height adjustable extension tab is actuatable to an extended / retracted position using a mechanical, hydraulic, electrical, electronic and / or pneumatic actuation action.

[0027] Preferably, each user-operable height adjustable extension tab is in communication with a corresponding user-engageable knob, wherein the user-engageable knob provides extension / retraction of the corresponding user-operable height adjustable extension tab by adjustability via rotational and / or vertical movement.

[0028] In an alternative embodiment, each operable height-adjustable extension tab can be remotely operated via an electromagnetic radiation signal to remotely control the user-operable height-adjustable extension tab to extend to and retract from the underside and / or the enclosed slot on the underside of the joint pad.

[0029] Preferably, each user-operable height-adjustable extension tab includes a bladder, wherein the bladder enables the user-operable height-adjustable extension tab to extend from the underside of the joint pad, and deflation of the bladder device causes the user-operable height-adjustable extension tab to retract toward the underside of the joint pad and / or rearwardly within the underside of the joint pad.

[0030] Preferably, the bladder is air-inflatable or fluid-controlled, including hydraulic.

[0031] Preferably, expansion and contraction of the bladder by inflation is provided by pneumatic means.

[0032] In an alternative embodiment, preferably, each user-operable height-adjustable extension tab can be telescopically extended into and retracted from the underside of the joint pad or a corresponding slot on the bottom side of the underside of the joint pad.

[0033] In an alternative embodiment of the present invention, the device does not include a plurality of user-operable height-adjustable extension tabs extending from the underside of the joint pad, but instead includes a separate plate adapted to engage with the underside of the joint pad, and wherein the separate plate will include slots in which corresponding user-operable height-adjustable extension tabs will be accommodated.

[0034] In this alternative form of the invention, although the device also includes a separate plate to the joint liner, space savings can still be achieved because the user-operable height adjustable extension tabs in their retracted position remain fully enclosed within the narrow slots on the underside of the preparation plate.

[0035] Thus, the preparation plate is able to be initially maintained flush with the surface of the initially resected proximal surface of the tibia, wherein height adjustment is achieved by the user engaging a user-operable height-adjustable extension tab to extend from the underside of a separate preparation plate to engage the surface of the initially resected tibia, but height adjustment of a corresponding operable height-adjustable extension tab extending from the preparation plate will still orient the underside of the joint pad so as to establish the desired definable reference plane which is then replicated as the final cutting contour to the proximal surface of the tibia.

[0036] As stated above, a primary focus of the present invention is the ability to minimize the spacing required to accommodate components that help establish a defined reference plane that will ultimately be resected as the final cut on the proximal tibia surface.

[0037] The actual means and method of translating the established reference plane are not essential to the main technical concept of the present invention, but may include the following preferred methods.

[0038] Preferably, the final bone resection of the proximal tibia surface comprises an electronic system device including an input signal, wherein the input signal entering the electronic system device provides tibial reference plane measurement data information, wherein the tibial reference plane measurement data information includes a spatial direction, angle and / or position of a tibial reference plane defined by the underside of the joint pad;

[0039] The electronic system device is configured to transmit electrical energy in the form of an output action in response to an input signal of the tibial reference plane measurement data information to align the blade and / or cutting tool at an angle so that, under the alignment of the blade and / or cutting tool provided by the tibial reference plane measurement data information, bone resection on or beneath the proximal surface of the tibia replicates the tibial reference plane on the proximal surface of the final resected tibia.

[0040] In an alternative embodiment, the final bone resection of the proximal tibia surface includes a tibial cutting guide device, the cutting guide device for the final bone resection of the proximal tibia surface includes a cutting guide having an indicator, wherein the indicator provides a reference guide for a cutting blade or saw to cut the final bone resection of the proximal tibia surface, and wherein the joint pad and the cutting guide device for the final bone resection of the proximal tibia surface include a mounting device, wherein the mounting device is configured to provide a first mounting position between the joint pad and the cutting guide device for the final bone resection of the proximal tibia surface, wherein the indicator of the cutting guide is aligned with a reference plane that is the same as the reference plane defined by the underside of the joint pad, and wherein the mounting device is further configured to provide a second mounting position, wherein the indicator of the cutting guide device aligned with the same reference plane of the underside of the joint pad can be adjusted below the proximal surface of the initial resection of the tibia.

[0041] Preferably, the mounting means is configured to provide a first mounting position between the tibial and femoral stability gap preparation plates by means of at least one slot and at least one corresponding lug.

[0042] Preferably, the joint liner includes at least one slot and the cutting guide device for the final bone resection of the proximal tibia surface includes one or corresponding lugs for the slot or each slot, or wherein the joint liner includes at least one lug and the cutting guide device for the final bone resection of the proximal tibia surface includes one or corresponding slots for the lug or each lug.

[0043] Preferably, there is at least a pair of narrow grooves on the front side of the joint pad and a pair of corresponding lugs protruding from the front of the cutting guide device for the final bone resection of the proximal surface of the tibia, or there is at least a pair of lugs protruding from the front side of the joint pad and a pair of corresponding narrow grooves in the cutting guide device for the final bone resection of the proximal surface of the tibia.

[0044] Preferably, the mount provides the second mounting position by comprising a vertical support, wherein the vertical support allows the cutting guide to be vertically adjustable along said vertical support.

[0045] Preferably, the vertical support is adapted for incrementally adjusting and positioning the cutting guide vertically along said vertical support.

[0046] Preferably, the incremental vertical adjustment of the cutting guide along the vertical support comprises a ratchet arrangement.

[0047] In further embodiments of the invention, the vertical incremental adjustability of the cutting guide along the vertical support may include a clutch, an intermediate gear arrangement, and a cam.

[0048] Preferably, the indicator of the cutting guide includes a narrow slot into which a saw or blade used to complete the final bone resection of the proximal tibia surface can be guided into the narrow slot of the indicator of the cutting guide so as to orient the saw or blade to cut the proximal tibia surface with a contour commensurate with a reference plane established on the underside of the joint pad.

[0049] In another form of the invention, there is provided a device for providing a femoral component of an artificial knee joint with a proximal surface of the distal femur and the posterior femoral condyle of the femur, the device comprising:

[0050] a femoral component mountable to a femur such that a vertical portion of the femoral component is adapted to align with a distal end of the femur and a horizontal portion of the femoral component is adapted to align with a posterior femoral condyle of the femur;

[0051] said vertical portion of the femoral component including user-operable laterally adjustable extension tabs, wherein each user-operable laterally adjustable extension tab is adapted to engage an initially resected distal femur, such that lateral adjustment of the femoral component by said plurality of user-operable laterally adjustable extension tabs defines a stability gap derived from gap measurements taken in each of extension, midflexion, and flexion, wherein said stability gap is commensurate with a femoral reference plane defined by the vertical portion of the femoral component, wherein final bone resection of the distal femur contoured by the distal femoral reference plane provides balanced angular motion between the tibial component and the femoral component of the artificial knee joint throughout the arc of motion of extension, midflexion, and flexion post-operatively;

[0052] The horizontal portion of the femoral component includes a user-operable height-adjustable extension tab, wherein the user-operable height-adjustable extension tab of the femoral component is suitable for engaging an initial resection surface of the posterior femoral condyle of the femur, so that adjusting the vertical height of the horizontal portion of the femoral component by the multiple user-operable height-adjustable extension tabs on the initial resection surface of the posterior femoral condyle of the femur defines a stability gap obtained by gap measurements performed in each of extension, mid-flexion and flexion, wherein the stability gap is commensurate with a posterior femoral condyle reference plane on the horizontal portion of the femoral component, wherein the final bone resection relative to the posterior femoral condyle reference plane of the posterior femoral condyle of the femur provides balanced angular movement between the femoral component and the tibial component of the artificial knee joint throughout the entire arc of motion of extension, mid-flexion and flexion.

[0053] Preferably, the femoral component has a C-shape.

[0054] Preferably, the C-shape comprises a vertical portion between a horizontal portion at the bottom of the C-shape and a corresponding top portion at the top of the C-shape.

[0055] In an alternative embodiment of the invention, the femoral component is L-shaped.

[0056] Preferably, the vertical arm of the L-shape provides the vertical portion and the horizontal arm of the L-shape provides the horizontal portion.

[0057] In yet another form of the invention, there is provided a device for providing a femoral component of an artificial knee joint with a proximal surface of the distal femur and the posterior femoral condyle of the femur, the device comprising:

[0058] A generally L-shaped femoral clamp including a posterior side mountable to the femur and an anterior side engageable with the femoral component,

[0059] a vertical arm of a generally L-shaped femoral clamp including a user-operable laterally adjustable extension tab that is at least partially received within a posterior side of the vertical arm in a retracted position, wherein lateral adjustment by said plurality of user-operable laterally adjustable extension tabs provides a distal femoral reference plane defined by the vertical arm of the generally L-shaped femoral clamp when measurements are taken in extension, mid-flexion, and flexion, wherein final bone resection of the distal femur utilizing the contour of the distal femoral reference plane provides balanced angular motion between the tibial component and the femoral component of the artificial knee joint throughout the entire arc of motion of extension, mid-flexion, and flexion post-operatively; and

[0060] The horizontal arm of the L-shaped femoral clamp includes a user-operable height-adjustable extension tab at least partially housed within the top surface of the horizontal arm, wherein the user-operable height-adjustable extension tab is adapted to engage the initial resected surface of the posterior femoral condyle of the femur, thereby adjusting the vertical height of the horizontal portion of the L-shaped femoral clamp on the initial resected surface of the posterior femoral condyle of the femur by the multiple user-operable height-adjustable extension tabs when measuring in extension, mid-flexion and flexion, and defining a posterior femoral condyle reference plane on the horizontal arm of the L-shaped femoral clamp, wherein the final bone resection of the posterior femoral condyle reference plane of the posterior femoral condyle of the femur provides balanced angular movement between the femoral component and the tibial component of the artificial knee joint throughout the entire arc of motion of extension, mid-flexion and flexion.

[0061] Preferably, each user-operable height adjustable extension tab and each user-operable laterally adjustable extension tab is actuatable to an extended / retracted position using a mechanical, hydraulic, electrical, electronic and / or pneumatic actuation action.

[0062] Preferably, each user-operable height-adjustable extension tab and each user-operable laterally-adjustable extension tab is connected to a corresponding user-engageable knob, wherein the user-engageable knob provides extension / retraction of the corresponding user-operable height-adjustable extension tab through adjustability via rotational and / or vertical movement.

[0063] Preferably, each operable height-adjustable extension tab and each user-operable laterally-adjustable extension tab can be remotely operated by radio signals to remotely control the extension and retraction of the user-operable height-adjustable extension tab toward the underside of the joint pad and / or the closed slot on the underside and / or the underside.

[0064] Preferably, each user operable height adjustable extension tab and each user operable laterally adjustable extension tab comprises a bladder, wherein inflating the bladder provides extension of the user operable height adjustable extension tab and each user operable laterally adjustable extension tab.

[0065] Preferably, expansion and contraction of the bladder is by inflation and / or fluid control, and wherein inflation is provided by pneumatic means.

[0066] Preferably, each user-operable height adjustable extension tab and each user-operable laterally adjustable extension tab are telescopically extendable and retractable.

[0067] Preferably, the final bone resection includes a mechanical cutter.

[0068] Preferably, a pressure sensor device is also included.

[0069] In order now to describe the invention in more detail, a series of preferred embodiments of the invention will be shown with the aid of the following figures and accompanying text. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1a and Figure 1b A front bottom perspective view of a joint pad in a preferred embodiment of the present invention is shown, wherein Figure 1a A user-operable height-adjustable extension tab is shown in a retracted position within the underside of the joint liner, and wherein Figure 1b The user-operable height-adjustable extension tab is shown in a user-adjustable extended position from the underside of the joint pad.

[0071] Figure 2 is a front view of the joint pad with the user-operable height-adjustable extension tab in an extended position outwardly from a bottom surface of the underside of the joint pad.

[0072] Figures 3 to 9 is a schematic diagram showing the use of the device in a preferred embodiment of the present invention to prepare the proximal tibial surface.

[0073] Fig.10a and Fig.10b An alternative preferred embodiment of the user operable height adjustable extension tab of the present invention is shown, wherein Fig.10a A user-operable height-adjustable extension tab is shown in a retracted position, and wherein Fig.10b The user-operable height-adjustable extension tab is shown in an extended position outwardly from the underside of the joint pad.

[0074] Fig.11a and Fig.11b A further preferred embodiment of a user operable height adjustable extension tab is shown, wherein Fig.11a The user-operable height adjustable extension tab is shown in a retracted position, while Fig.11b The user-operable height adjustable extension tab is shown in an extended position.

[0075] Fig.12a and Figure 12b An alternative embodiment of the present invention is shown in which a user-operable height-adjustable extension tab is incorporated into a separate preparation board to extend from the underside of the preparation board, wherein Fig.12a A user-operable height adjustable extension tab is shown in a retracted position. Figure 12b in the extended position.

[0076] Fig.13ais a posterior perspective view of a device for providing proximal surface contours of the posterior femoral condyle of the distal femur and the femoral surface in a preferred embodiment of the present invention.

[0077] Fig.13b yes Fig.13a Front perspective view.

[0078] Fig.14a is another preferred embodiment of the present invention, showing an alternative shape of the femoral component.

[0079] Fig.14b yes Fig.14a Front perspective view of rear perspective view shown.

[0080] Fig.15a and Fig.15b Rear and front perspective views are shown of another embodiment of the present invention, wherein the device includes the use of an L-shaped femoral clamp. DETAILED DESCRIPTION

[0081] Referring now in more detail to the drawings, and in particular first to Figure 1a , Figure 1b and Figure 2 .

[0082] In a preferred embodiment, an apparatus for preparing a proximal tibial surface for a tibial component of a prosthetic knee joint is generally shown as (10).

[0083] The device includes a joint liner (12) having an underside generally indicated at (14) and a bottom surface (16) on the underside (14) of the joint liner (12).

[0084] The underside (14) of the joint pad (12) includes a series of slots (18, 20 and 22) surrounding respective user-operable height-adjustable extension tabs (24, 26 and 28).

[0085] These user-operable height-adjustable extension tabs (24, 26 and 28) are located as shown in FIG. Figure 1a shown in the retracted closed position, but can be Figure 1b and Figure 2 The height is shown extending therefrom so as to adjust the height to produce the necessary stability gap as measured in each of extension, midflexion and flexion, wherein the stability gap is commensurate with a reference plane which becomes definable with respect to the orientation on the underside of the joint substrate, which will be referred to later Figures 3 to 9 will be discussed in more detail later.

[0086] exist Figure 1a , Figure 1b and Figure 2In the preferred embodiment shown, user operable height adjustable extension tabs (24, 26 and 28) are extendable and retractable by the user engaging knobs (30, 32 and 34).

[0087] like Figure 1b and Figure 2 As shown by the arrows (36 and 38) in the figure, by rotating the knobs (30, 32 and 34), corresponding user-operable height-adjustable extension tabs (24, 26 and 28) can be extended starting from the bottom side (16) located on the underside (14) of the joint pad (12).

[0088] Nevertheless, the significance of this preferred embodiment of the present invention resides in the incorporation of the user-operable height-adjustable extension tabs (24, 26 and 28) enclosed within the joint liner (12) rather than as part of any separate plate assembly.

[0089] Advantageously, as opposed to a separate preparation plate, the user-operable height-adjustable extension tabs (24, 26 and 28) are not only located on the underside (14) of the joint pad (12), but they are also received and enclosed within slots (18, 20 and 22) defined in the bottom surface (16) of the underside (14) of the joint pad (12).

[0090] Incorporating user-operable, height-adjustable extension tabs (24, 26 and 28) into the joint liner (12) and further enclosing them in the slots (18, 20 and 22) means that the spacing required to manipulate the components can now be minimized to properly prepare the proximal tibial surface so that the final resected surface of the tibia will provide optimal balance and stability for the tibial component and / or femoral component of the artificial knee joint to allow stable and balanced movement of the knee joint throughout the entire angular motion from extension, mid-flexion to flexion and then back again.

[0091] about Figures 3 to 9 , illustrations need to be placed in the context of the expected results to be achieved by using the apparatus and methods provided in the present invention.

[0092] During surgery, the orthopedic surgeon aims to provide balanced, unobstructed movement of the knee components through a complete arc of motion from extension, midflexion, and flexion and back again.

[0093] Therefore, the final bone resection of the proximal tibial surface needs to be correctly cut to provide the appropriate contour for positioning of the tibial component in knee arthroplasty, whether total or unicompartmental knee surgery.

[0094] Figure 3 A knee joint generally at 39 is shown.

[0095] A cutter (not shown) has prepared an initial resection of the proximal surface 40 of the tibia 41. Also shown is the distal end of a generalized femur 42. Figure 3 In FIG. 4 , the joint liner 12 indicated by arrow 43 is inserted onto the initially resected proximal surface 40 of the tibia 41 .

[0096] from Figure 3 It will be appreciated that the general shape and dimensions of the bottom surface 16 of the joint liner 12 are of comparable dimensions to the proximal surface 40 of the tibia 41 .

[0097] Figure 4 The actual positioning of the articular liner 12 on the proximal surface 40 of the tibia 41 is shown, with the articular liner 12 sandwiched between the femoral component 42 and the tibia 41 .

[0098] The joint liner 12 has an articulating upper surface 44 to engage a femoral component 45 of the femur 42 .

[0099] Importantly, the joint liner 12 on the front side 46 includes a pair of slots 47, which are preferably not substantially identical to the slots 47 of the joint liner 12. Figure 6 This pair of slots 47 will be discussed in more detail when the mounting device is described between the cutting guide device 48 for the final bone resection of the proximal surface of the tibia (introduced in the).

[0100] Figure 5 The knee joint is shown in a neutral flexion position. Operable knobs 30, 32 and 34, when rotated as indicated by arrows 67, 67 and 67, adjust the height of corresponding user operable height adjustable extension tabs (24, 26 and 28) extending from the underside of the joint pad (12) Figure 5 ), the joint pad (12) then also adjusts the orientation, reference plane, of the bottom surface 16 of the underside 14 of the joint pad 12. Figure 5 Arrow 48 in illustrative figures represents the upward movement of the joint pad 12 and the orientation of the bottom surface 16 of the underside 14 of the joint pad 12 .

[0101] This height adjustability, although not shown in the illustration, is also accomplished in extension, mid-flexion, and ultimately in flexion or 90 degrees.

[0102] Thus, the user-operable height-adjustable extension tabs 24, 26 and 28 form a triangular support for the top surface 40 of the tibia 41, which is then correspondingly aligned and / or oriented to the bottom surface 16 on the underside 14 of the joint liner 12. The stability gap that has been established is commensurate with the reference plane on the bottom surface 16 on the underside 14 of the joint liner 12 that has now been established by the height adjustability of the height-adjustable extension tabs 24, 26 and 28 in extension, midflexion and flexion.

[0103] Thus, while the stability gap is provided by the measurement of the height adjustability of the height adjustable extension tabs 24 , 26 and 28 in extension, mid-flexion and flexion, the stability gap is then represented by the reference plane on the bottom surface 16 now provided on the underside 14 of the joint pad 12 .

[0104] Now that a reference plane is established on the bottom surface 16 on the underside 14 of the joint liner 12 , the goal is then to translate that reference plane during the final bone resection of the proximal tibia surface, which is accomplished by using a cutting guide 48 that can be mounted to the joint liner 12 .

[0105] like Figure 6 As best shown in FIG. 4 , the cutting guide device 48 for final bone resection of the proximal tibia surface includes a cutting guide 49 , wherein the cutting guide 49 includes an indicator in the form of a slot 50 .

[0106] The purpose of the slot 50 is to allow the blade or saw to be guided to make the final resection cut on the proximal tibia surface in a direction aligned with the slot 50 .

[0107] Therefore, it is desired that the indicator (which in the preferred embodiment is a slot 50 included as part of the cutting guide 49 ) be identically aligned with the bottom surface 16 on the underside 14 of the joint pad 12 .

[0108] The cutting guide 48 for final bone resection of the proximal tibia surface, which is part of the mounting device between the cutting guide 42 for final bone resection of the proximal tibia surface and the joint liner 12, includes a pair of lug extensions or protrusions 51, which are suitable for being placed in a corresponding pair of narrow grooves 47 on the front side 46 of the joint liner 12.

[0109] Figure 7 A cutting guide 48 for final bone resection of the proximal tibia surface mounted to a joint liner 12 is shown, wherein the engagement between the lug extension 51 of the cutting guide 48 for final bone resection of the proximal tibia surface and the pair of narrow grooves 47 on the front side 46 on the joint liner 12 means that the indicator groove 50 of the cutting guide 49 is aligned in the same direction as the reference plane of the bottom surface 16 on the lower side 14 of the joint liner 12.

[0110] As contemplated, prior to any height adjustment of the user-operable height-adjustable extension tabs 24, 26 and 28, the pair of slots 47 of the joint pad 12 will be generally aligned with the Figure 3 The initial resection surface 40 of the tibia 41 is shown on a consistent horizontal plane.

[0111] Nevertheless, as the user operable height adjustable extension tabs 24 , 26 and 28 are adjusted to provide a stable gap, this then changes the orientation of the bottom surface 16 on the underside 14 of the joint pad 12 , and thus changes the orientation of the corresponding slot 47 on the front side 46 of the joint pad 12 .

[0112] Thus, since the pair of slots 47 of the joint liner 12 have now been offset by height adjustment, the corresponding lug extensions 51 of the cutting guide 48 for final bone resection of the proximal tibia surface will also be offset so that the indicator groove 50 of the cutting guide 49 will represent the same reference plane on the bottom surface 16 present on the lower side 14 of the joint liner 12.

[0113] Figure 7 This mounting engagement between the joint liner 12 and the cutting guide 48 of the final bone resection of the proximal tibia surface shown in FIG. 4 provides a first mounting position.

[0114] A second mounting position then needs to be established so that the cutting guide 49 and, in particular, the properly aligned indicator groove 50, now oriented identically to the reference plane on the bottom surface 16 on the underside 14 of the joint liner 12, can cut into new bone layers below the initial resection surface 40 of the tibia 41.

[0115] By using the vertical support seat 53 included as part of the cutting guide device 48 for the final bone resection of the proximal surface of the tibia, the cutting guide 49 can be as Figure 7 As shown by arrow 54 , the vertical support 53 is adjusted incrementally therein vertically.

[0116] Vertical adjustment of the cutting guide 49 as part of the cutting guide 48 for the final bone resection of the proximal surface may be accomplished by conventional incremental adjustments, such as through the use of a ratchet, gear arrangement, cam, or the like.

[0117] like Figure 8 As seen in FIG. 4 , once the cutting guide 49 has been lowered, the cutting guide 49 can then be separated from the cutting guide 48 for final bone resection of the proximal tibia surface. The vertical support 53 is also withdrawn.

[0118] Although the mounting arrangement is not shown, the cutting guide 49 is mounted to the tibia 41 in a second mounting position provided by a vertical mount 53 that includes a portion of the cutting guide 48 for final bone resection of the proximal surface of the tibia.

[0119] Therefore, if Figure 8 As shown, the second mounting position has a cutting guide 49 that can be secured in a correct vertical position for cutting into new bone beneath the initially resected proximal surface 40 of the tibia 41 .

[0120] Likewise, the indicator groove 50 for proper orientation is aligned with the same reference plane established on the bottom surface 16 on the underside 14 of the joint pad 12 .

[0121] However, the practicality of final resection requires the withdrawal of the main infrastructure of the cutting guide 48 for final bone resection of the tibia. Therefore, once the second installation position is established, such as Figure 8 The illustrated cutting guide 49 will be mounted to the tibia 41 via various pins and / or bolts (not shown).

[0122] like Figure 8 4, the cutting guide 49 is mounted with an indicator slot 50 that is properly aligned and at the appropriate depth below the initially resected proximal surface 40 of the tibia 41, wherein a blade or saw 56 can be guided and oriented through the slot 50 to enable a final bone resection that provides a contour of the proximal tibia surface that is identical to the reference plane, shown as Fig. 9 57, ensures a stability gap so that the tibial component of the artificial knee (not shown) is inserted stably and balanced throughout the entire arc of motion of the artificial knee joint (not shown), which is what people expect for an ideally balanced knee replacement.

[0123] Fig.10a and Fig.10b Another preferred embodiment of the present invention is shown which focuses on the type of user operable height adjustable extension tab.

[0124] exist Fig.10a and Fig.10b In the illustrated alternative preferred embodiment, the user operable height adjustable extension tabs (86, 88 and 90) are inflatable bladders or balloons, such as Fig.10a Shown uninflated and therefore in a retracted configuration housed within the underside (84) of the joint liner (80).

[0125] like Fig.10b As shown by arrows (92) in FIG. 8 , the user-operable height-adjustable extension tabs (86, 88 and 90) expand to an extended height-adjustment position.

[0126] Fig.11a and Fig.11b A further preferred embodiment of user operable height adjustable extension tabs (93, 94 and 95) is shown. Fig.11a and Fig.11b In the preferred embodiment shown, user-operable height-adjustable extension tabs (93, 94 and 95) are telescopically received within the underside (84) of the joint pad (80) and extendable outwardly to their desired height-adjustable extended positions, such as Fig.11b shown.

[0127] Fig.10a and Fig.10b Another preferred embodiment of the present invention is shown, wherein user-operable height-adjustable extension tabs (110, 112 and 114) are enclosed within the interior of the Fig.12a and Figure 12b The preparation shown is within the slots (104, 106 and 108) in the underside (102) of the plate (100), rather than being incorporated into the joint liner. Figure 12b The arrows (121) in FIG. 1 represent the vertical movement of the height-adjustable extension tabs (110, 112 and 114).

[0128] By introducing these slots (104, 106 and 108) into the preparation plate (102), there is still a degree of space saving so that the starting point of the user-operable height-adjustable extension tabs (110, 112 and 114) allows the bottom surface (102) of the preparation plate (100) to remain flush with the surface of the initially resected proximal surface of the tibia.

[0129] refer to Fig.13a and Fig.13b , wherein an apparatus for providing a femoral component of an artificial knee joint with a shaped proximal surface of the distal femur and a shaped proximal surface of the posterior femoral condyle of the femur is generally shown as (200).

[0130] The device (200) includes a femoral component (202) having a generally C-shaped configuration mountable to a femur. Fig.13a and Fig.13b In the preferred embodiment shown, this initial installation of the femoral component (202) to the femur can be aided by mounting holes (203) so that the vertical portion, generally shown as (204), will be aligned with the distal end of the femur and the horizontal portion (206) at the base (207) of the C-shaped structure will be generally aligned with the posterior femoral condyle of the femur.

[0131] The generally C-shape of the femoral component (202) has a generally flat top portion (208).

[0132] Importantly to the present invention, the vertical portion (204) of the femoral component (202) includes a medial or posterior side (214) of the femoral component (202) (with Fig.13b The femoral component is shown with user-operable laterally adjustable extension tabs (210) and (212) on the anterior side (opposite to the anterior side (216)) of the femoral component.

[0133] These user-operable laterally adjustable extension tabs (210) (212) are adapted to engage the initially resected distal end of the femur so as to provide a final stability gap when gap measurements are made during extension, mid-flexion, and flexion when the femoral component (202) is laterally adjusted via the user-operable laterally adjustable extension tabs (210) (212) to provide a final stability gap when these measurements are completed, wherein a distal femoral reference plane is defined based on or by the orientation of the vertical portion (204) of the femoral component (202).

[0134] The establishment of this femoral reference plane based on or defined by the orientation of the vertical portion (204) of the femoral component (202) if then replicated as the same contour for the final bone resection on the distal femur will allow for optimally balanced angular movement between the tibial component and the actual femoral component which will form part of the artificial knee joint throughout the entire arc of motion of extension, flexion and mid-flexion post-operatively.

[0135] Also important to the present invention, the femoral component (202) on the horizontal portion (206) includes user-operable height-adjustable extension tabs (218) and (219) at the base (207) of the femoral component (202), wherein these user-operable height-adjustable extension tabs (218) and (219) are adapted to engage the initially resected surface of the posterior femoral condyle of the femur so as to adjust the vertical height of the horizontal portion of the femoral component (202) when measurements are taken in extension, mid-flexion and flexion, which defines a posterior femoral condyle reference plane on the horizontal portion (206) of the femoral component (202), which then, if replicated as the final bone resection of the posterior femoral condyle, will provide an optimally balanced angular motion between the femoral component and the tibial component, which will form part of the artificial knee joint throughout the entire arc of motion of extension, mid-flexion and flexion.

[0136] Advantageously for the present invention, rather than having an additional component with adjustable tabs attached as was the case in the applicant's earlier invention WO2017197462, in this case these tabs are incorporated into the conventional femoral component which has now been improved.

[0137] By eliminating the additional components required to establish the relevant femoral reference planes, this means a savings in the space required for proper preparation of the proximal surfaces of the femur, thereby minimizing the depth or amount of bone that initially needs to be cut at these end surfaces of the femur.

[0138] Fig.14a and Fig.14b An alternative shape for the femoral component is provided, this time shown as (220), presenting a more L-shaped appearance, including a vertical arm (222) and a horizontal arm (224).

[0139] Fig.14aand Fig.14b The function and operation of the femoral component (220) shown in FIG. Fig.13a and Fig.13b The same as discussed above with respect to the mountability of the femoral component (222) in the preferred embodiment through the mounting hole (226) and the adjustability (the associated reference planes are created by user-operable laterally adjustable extension tabs (228) and (230) on the vertical arm (222) of the femoral component (220) and user-operable height adjustable extension tabs (232) and (234) on the vertical portion (224) of the femoral component (220)).

[0140] Fig.15a and Fig.15b Yet another preferred embodiment of the present invention is shown wherein the depth required to be resected from the proximal surface of the femur during the initial resection of the procedure is minimized by at least partially incorporating user-operable laterally adjustable extension tabs (238) and (240) into the posterior side (234) of the generally L-shaped femoral clamp (230).

[0141] The posterior surface (234) of the vertical arm (235) of the generally L-shaped femoral clamp (230) is oriented so that user-operable laterally adjustable extension tabs (238) and (240) are capable of engaging with the initially resected distal end of the femur, wherein user-operable height-adjustable extension tabs (242) and (244) as part of the corresponding horizontal arm portions (236a) and (236b) are then adapted to engage with the initially resected surface of the posterior femoral condyle of the femur.

[0142] again, Fig.15a and Fig.15b The embodiment shown in differs from the applicant's earlier device shown in WO2017197462 in that the associated user-operable extension tabs positioned on the vertical and horizontal arms rather than engaging with the front plate (232) are placed on the inner surface of the vertical arm and the top surface (239) of the horizontal portions (236a) and (236b), and importantly, are at least partially enclosed within this rear surface (234) and top surface (239) when the extension tabs (238), (240), (242) and (244) are in a generally retracted position.

Claims

1. A device for preparing a proximal tibial surface for a tibial component of an artificial knee joint, the device comprising: A joint liner (12) comprising an upper articulating surface (44) engaging a femoral component of a knee joint, the joint liner (12) further comprising a plurality of user-operable height-adjustable extension tabs (24, 26, 28), wherein the plurality of user-operable height-adjustable extension tabs (24, 26, 28) are height-adjustable from an underside (14) of the joint liner (12), such that height adjustment of the plurality of user-operable height-adjustable extension tabs (24, 26, 28) is configured to define a stability gap derived from gap measurements taken in each of extension, mid-flexion, and flexion, wherein the stability gap is commensurate with a tibial reference plane defined on a surface of the underside (14) of the joint liner (12), wherein final bone resection of the proximal tibial surface coinciding with the tibial reference plane provides balanced angular motion between the tibial component and the femoral component of the artificial knee joint throughout the entire arc of extension, mid-flexion, and flexion; Among other things, the device eliminates a separate preparation plate including height-adjustable extension tabs, thereby reducing the spacing required for preparation of the proximal tibial surface by establishing a tibial reference surface, thereby minimizing the depth or amount of bone that initially needs to be resected from the end of the tibia.

2. The device according to claim 1, wherein the joint pad (12) includes a plurality of narrow slots (18, 20, 22) on the underside (14) of the joint pad (12), wherein corresponding user-operable height-adjustable extension tabs (24, 26, 28) of the plurality of user-operable height-adjustable extension tabs are enclosed or at least substantially enclosed therein.

3. A device according to claim 1 or 2, wherein the plurality of user-operable height-adjustable extension tabs (24, 26, 28) includes three operable height-adjustable extension tabs (24, 26, 28), and wherein the joint pad (12) includes three corresponding slots (18, 20, 22), wherein each corresponding slot of the joint pad (12) surrounds a corresponding user-operable height-adjustable extension tab.

4. The device of claim 1, wherein each user-operable height-adjustable extension tab (24, 26, 28) is actuatable to an extended / retracted position using a mechanical, hydraulic, electrical, electronic and / or pneumatic actuation action.

5. The apparatus of claim 1 , wherein each user-operable height-adjustable extension tab (24, 26, 28) is in communication with a corresponding user-engageable knob, wherein adjustability of the user-engageable knob (30, 32, 34) by rotation and / or vertical movement provides extension / retraction of the corresponding user-operable height-adjustable extension tab.

6. A device according to claim 1, wherein each user-operable height-adjustable extension tab (24, 26, 28) can be remotely operated by a radio signal to remotely control the user-operable height-adjustable extension tab to extend to the underside (14) of the joint pad (12) and / or the closed slot on the underside (14) and to retract from the underside (14) of the joint pad (12) and / or the closed slot on the underside (14).

7. The device of claim 1, wherein each user-operable height-adjustable extension tab (24, 26, 28) comprises a bladder (86, 88, 90), wherein expansion of the bladder (86, 88, 90) causes extension of the user-operable height-adjustable extension tab (24, 26, 28) from the underside (14) of the joint pad (12), and contraction of the bladder (86, 88, 90) retracts the user-operable height-adjustable extension tab (24, 26, 28) toward the underside (14) of the joint pad (12) and / or within the underside (14) of the joint pad (12).

8. The device of claim 7, wherein the expansion and contraction of the bladder (86, 88, 90) is performed by inflation and / or fluid control, and wherein the inflation is provided by pneumatic means.

9. The device of claim 1, wherein each user-operable height-adjustable extension tab (24, 26, 28) is telescopically extendable into and retractable from the underside (14) of the joint pad (12) or a corresponding slot on the bottom side of the underside (14) of the joint pad (12).

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