WO2025235387A1

WO2025235387A1 - Tensioning workflow for a surgical procedure

Info

Publication number: WO2025235387A1
Application number: PCT/US2025/027764
Authority: WO
Inventors: Timothy Alton
Original assignee: Individual
Current assignee: Individual
Priority date: 2024-05-06
Filing date: 2025-05-05
Publication date: 2025-11-13
Anticipated expiration: 2026-11-06

Abstract

A method for establishing placement of a guide includes determining a bone cut to be made to a first bone of a joint as part of a surgical procedure and selecting a guide based on the determining. The method further includes tensioning soft tissues of the joint using a tensioner inserted into the joint between a first bone and a second bone, connecting the guide to the tensioner, and positioning the guide on the first bone with the soft tissues tensioned by the tensioner. A system for positioning a guide relative to patient anatomy is also provided, as is an apparatus for placement of a guide on a bone as part of a surgical procedure.

Description

TENSIONING WORKFLOW FOR A SURGICAL PROCEDURE

BACKGROUND

[0001] Aspects described herein relate to surgical applications, and more specifically to apparatuses and processes utilizing a tensioner and surgical guide(s) during a total knee arthroplasty.

SUMMARY

[0002] Shortcomings of the prior art are overcome and additional advantages are provided through the provision herein of apparatuses and processes for utilizing a tensioner and surgical guides during surgical procedures.

[0003] Additional aspects are provided in the disclosure. The present summary is not intended to illustrate each aspect of, every implementation of, and/or every embodiment of the present disclosure. Additional features and advantages are realized through the concepts described herein.

[0004] In an aspect, a method for establishing placement of a guide includes determining a bone cut to be made to a first bone as part of a surgical procedure, selecting a guide based on the determining, tensioning soft tissues of the joint using a tensioner inserted into the joint between the first bone and the second bone, connecting the guide to the tensioner, and positioning the guide on the first bone with the soft tissues tensioned by the tensioner.

[0005] In an aspect, the joint is a knee joint, and the tensioning tensions the knee joint in extension. In another aspect, the joint is a knee joint, and the tensioning tensions the knee joint in flexion.

[0006] In an aspect, the connecting the guide to the tensioner includes rigidly connecting the guide to the tensioner based on a determined first distance between a desired location of the bone cut and a portion of the tensioner that abuts a second bone of the joint based on the tensioner being inserted into the joint and tensioning the soft tissues. In an aspect, the guide is a pin guide or a drill guide including a guide hole, and the rigidly connecting is further based on a determined second distance between the desired location and the guide hole of the guide. In an aspect, the positioning further includes positioning the guide on the first bone based on the rigidly connecting the tensioner to the guide, and the method further includes inserting a pin in the first bone using the guide hole or drilling a drill hole into the first bone using the guide hole, and placing a cutting block against the first bone using the pin or the drill hole, wherein the placing aligns a cutting slot of the cutting block with the desired location of the bone cut.

[0007] In another aspect, the guide is a cut guide, and the connecting the cut guide to the tensioner includes rigidly connecting the tensioner to the cut guide based on a determined distance between a desired location of the bone cut and a portion of the tensioner that abuts the second bone of the joint based on the tensioner being inserted into the joint and tensioning the soft tissues. In an aspect, the cut guide is a multiplecut cutting guide or a distal femoral cutting guide.

[0008] In another aspect, the connecting the guide to the tensioner further includes determining a first distance between a desired location of the bone cut and a fixation hole of the guide when then the guide is to contact the first bone, and determining a second distance between the desired location and a portion of the tensioner that is to contact the second bone of the joint based on the tensioner being inserted into the joint and tensioning the soft tissues. In an aspect, the connecting the guide to the tensioner further includes determining, based on the first distance and the second distance, a third distance between the fixation hole and the portion of the tensioner, and rigidly connecting the guide to the tensioner based on the determined third distance. In an aspect, the positioning the guide on the first bone positions the guide based on the connecting the guide to the tensioner, wherein the positioning provides a fixed distance between the fixation hole and the portion of the tensioner based on the tensioner being inserted into the joint and tensioning the soft tissues that is equal to the third distance.

[0009] In yet another aspect, a system for positioning a guide relative to patient anatomy includes a tensioner configured to tension soft tissues of a joint based on insertion of the tensioner between a first bone and a second bone of the joint, the tensioner having a first contacting surface and a second contacting surface, the first contacting surface configured to contact the first bone and the second contacting surface configured to contact the second bone. The system further includes a guide configured to establish a position of a bone cut to be made to the first bone as part of a surgical procedure, and a link configured to rigidly connect the tensioner to the guide.

[0010] In an aspect, the link is further configured to rigidly connect the second contacting surface to the guide. In an aspect, the link is further configured to rigidly connect the tensioner to the guide based on a desired distance between at least a portion of the second contacting surface and a hole of the guide. In an aspect, a length of the link to connect the tensioner to the guide is selected based on a desired distance between at least a portion of the second contacting surface and the bone cut to be made.

[0011] In an aspect, the guide is a first guide, and the link is further configured to fix a position of a hole of the first guide relative to at least a portion of the tensioner based on the second contacting surface being rigidly connected to the first guide, such that connecting the first guide to the tensioner results, based on the tensioner being inserted into the joint and tensioning the soft tissues, in the hole being aligned with a desired location of the bone cut or a desired location of a fixation member to be received by a second guide. In an aspect, the second guide is a cut guide, and the link is configured such that the connecting the guide to the tensioner results, based on the tensioner being inserted into the joint and tensioning the soft tissues, in the hole being aligned with the desired location of the fixation member.

[0012] In yet another aspect, an apparatus for placement of a guide on a bone as part of a surgical procedure includes a tensioner and a guide rigidly connected to the tensioner, wherein the guide includes a pin guide, a drill guide, or a cut guide.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Aspects described herein are particularly pointed out and distinctly claimed as examples in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

[0014] FIG. 1 shows example cartilage wear levels of the proximal portion of a patient tibia; [0015] FIG. 2 depicts an example varus adjustment for tibial resection planning, in accordance with aspects described herein;

[0016] FIG 3 A, depicts an example arrangement of a tensioner and connected cutting block for a distal femur cut, in accordance with aspects described herein;

[0017] FIG. 3B depicts an example arrangement of a tensioner and connected cutting block for anterior, posterior, and chamfer femur cuts, in accordance with aspects described herein;

[0018] FIG. 4A depicts an example of a tensioner connected to a pin guide by a linking device in accordance with aspects described herein;

[0019] FIG. 4B depicts the example of FIG. 4 A in which a cutting block has been placed on a patient’s femur following a pin placement in accordance with aspects described herein;

[0020] FIG. 4C depicts an example of a tensioner connected to a cutting block using a linking device in accordance with aspects described herein; and

[0021] FIG. 5 depicts an example computer system to perform aspects described herein.

DETAILED DESCRIPTION

[0022] Example processes for accommodating the use of a tensioner connected to a surgical guide, such as a pin guide, a drill guide, and/or a cutting guide (also referred to as a cut guide or cutting block, for instance, a distal femoral cutting block and/or a multiple cut cutting block such as a 2-in-l cutting block, a 3-in-l cutting block, a 4-in-l cutting block, etc.) for a total knee arthroplasty (TKA) are described herein, though aspects herein may be used with other types of surgical procedures.

[0023] A tensioner may typically be used during certain surgical procedures, such as a TKA performed as a manual, robot-assisted, or robot-navigated surgical procedure. A tensioner enables a surgeon to obtain balance (e.g., knee balance) with bone cuts, rather than with soft tissue releases. The accuracy, precision, and quality of data obtained from the use of a tensioner is particularly strong, allowing for surgeons to focus on kinematic alignment or soft tissue balance, as opposed to relying on traditional techniques of neutral mechanical bone alignment. Generally, robot-assisted and robot-navigated surgeries utilize three dimensional (3D) models of the patient’s anatomy. The models are created using, for example, computed tomography (CT) scans or intra-operative registration and are used to plan surgical cuts. Some systems may use traditional cutting blocks to guide cuts during a TKA.

[0024] After a tibial resection is performed during a TKA, a tensioner may be inserted to apply a measurable and reproducible stress to the soft tissue envelope of the knee. The surgeon may then adjust the resection plan based on the data provided by the tensioner to optimize soft tissue balance. Soft tissue balance is the principle that the ligaments and other soft tissues of the knee experience the same forces and stress after the knee replacement as they did with a native, non-replaced knee.

[0025] To accomplish soft tissue balance, surgeons may measure the distance between known anatomic points on the femur and the tibia. These distances are referred to as “gaps.” Bone cuts (e.g., resections) on the proximal tibia and distal femur are then performed to create desired distances between the resected femur and tibia bones to accommodate implants. It may be ideal if these gap measurements are performed when force, or stress, is applied to the knee, because applying such force or stress may best approximate the conditions the knee experiences during regular use. For example, manual force or stress may be applied to the knee by a surgical team. However, manual application of force or stress to the knee may produce a great deal of variation, calling into question its reliability. Further, manual application of force or stress to the knee may be exceptionally difficult to teach and reproduce, especially from one surgery and/or surgeon to another.

[0026] Alternatively, a tensioner may be used to overcome the limitations of manual application of force or stress to the knee. One key to the success of tensioner use is the principle that the tibia is to be resected before the femur, which lays a foundation for the knee replacement. Osteophytes and other soft-tissue-impacting structures are removed prior to insertion of the tensioner, and the tensioner is then inserted to apply force or stress to the soft tissue envelope, including to the collateral ligaments, capsule and tendons, at varying degrees of extension and/or flexion.

[0027] The amount of femur that is cut can be optimized based on the gap(s) that the surgeon desires to create between the femur and tibia. Presently, this is difficult to achieve absent the use of navigation technology because these gap distances are harder to quantify without navigation. These gap distances are therefore estimated by surgeon “feel” or static spacer blocks, for example, which has drawbacks including inaccuracy, lack of reproducibility and repeatability, and human error.

[0028] As an alternative to large navigated or robot-assisted systems, which may be expensive to create or operate, and which may not be widely available, surgeons may utilize aspects of the instant disclosure, which involve the use of an intraoperative tensioner connected to (1) a drill guide, (2) a pin guide, and/or (3) a cutting guide and/or block (collectively, drill guides, pin guides and cutting blocks may be referred to herein generally as “guides”) to both tension and assist with cutting a knee during a TKA. More specifically, described herein are processes which may utilize novel apparatus(es) for placement of a guide on a bone as part of a surgical procedure. In embodiments, an apparatus of the instant disclosure includes a tensioner and a guide rigidly connected to the tensioner, wherein the guide includes a pin guide, a drill guide, or a cut guide (e.g., cutting block).

[0029] As explained in more detail herein, the use of a tensioner physically connected to a guide to help restrict, in part, the placement of a guide to achieve a proper distance from the tensioner or corresponding anatomical location, such as the tibial shelf, allows the surgeon to reliably apply reproducible intraoperative tension (e.g., force or stress by way of the tensioner) to the soft tissue envelope, and then set the amount of femur to be cut (resection depth) while the soft tissue envelope remains tensioned by the tensioner. If placement of the guide is made without properly tensioning the joint, then this might yield an undesirable result in terms of femoral resection placement when the knee is later tensioned from implant insertion. In other words, having the joint in tension in order to then place/locate the specific resection location on the bone ensures that the desired distance or other spatial relation provided by the link between the guide and the tensioner is attained for the tensioned joint.

[0030] Physical connection of the tensioner to the guide links the two together and imparts a known and/or measurable relation between them, such as an exact distance between known points on the guide (such as a pin hole or a cutting slot) and a known point of the tensioner, for example. In other words, the known physical relationship (distance(s), for instance) between a linked guide and tensioner can be leveraged when positioning the guide on patient bone as the tensioner has desirably tensioned the patient joint to ensure that the same distance(s) are translated to the tensioned patient anatomy to thereby achieve positionally-accurate resections. The tensioner connected to a guide may be utilized both for the flexion space and for the extension space as explained herein to obtain soft tissue balance without the need for soft tissue releases and/or robotics (e.g., robot navigated or assisted procedures).

[0031] In an aspect, the tibia may be cut first (i.e., before the femur) during a TKA. The tibia may be cut as an anatomic resection based on wear, as discussed herein. Alternatively, a surgeon may choose to cut the tibia in neutral mechanical alignment and/or with the surgeon’s own preferred guardrails. The surgeon can also remove at least the meniscus and extra bone (e.g., osteophytes) before tensioning the soft tissue envelope. After tibial resection and desired cleanout, the tensioner may be placed into the knee joint, and the knee joint may be moved into extension (and/or flexion) and held in place (e.g., via instrumentation or manually by the surgeon). The tensioner is then used to tension the soft tissues. In embodiments, the tensioner may include a first contacting surface and a second contacting surface, such that the first contacting surface may contact the tibia and the second contacting surface may contact the femur. The surfaces may this be outer ‘top’ and ‘bottom’ surfaces of the tensioner. In such embodiments, the tensioner applies forces in opposite directions between the tibia and the femur, wherein the first contacting surface and the second contacting surface push against the tibia and the femur, respectively, to tension the soft tissues. The tensioner can be of any type. In examples, the tensioner is a springbased tensioner. In other examples, the tensioner is a digital tensioner. Other types of tensioners may also be used.

[0032] With the knee joint in extension, a cutting block for cutting the distal femur (and potentially other guide(s) to facilitate placement and fixation of the cutting block) may be attached to the anterior femur. In an aspect, this may be achieved by first linking a pin guide or a drill guide to the tensioner to use for proper drilling/pin placement and then subsequently, after use of the pin/drill guide, placement of the cutting block based on that. The pin guide or drill guide may include and/or hold a track for pins to be placed or holes to be drilled, as the case may be, into the femur. The pin guide or drill guide may allow for pins to be placed into the femur at the correct distance from the end of the femur and properly positioned with respect to the top of the (resected) tibia to inform and/or guide the correct amount of distal femur to be removed. Once the holes have been drilled and/or the pins have been placed, the pin guide or drill guide may be removed (e.g., disconnected from the tensioner and removed from the knee joint) and the cutting block may be positioned against the femur, for instance by sliding down and/or over the pins for secure attachment to the anterior femur. In this manner, the initial positioning of the pin guide or drill guide dictates placement of the resection on account that the cut guide’s placement is based on the placement of the pin guide or drill guide.

[0033] In another aspect, the cutting block may be directly linked to the tensioner for proper cut guide placement, rather than the tensioner being linked first to a pin guide or the drill guide to dictate positioning of the cut guide when placed. A cutting block linked to the tensioner may be attached directly to the femur (e.g., with pins), without the use of a pin guide or drill guide. After the pins are placed to pin the cutting block, at least the tensioner may be removed, if desired, leaving the cutting block in place in and/or on the bone. Regardless of the how the cutting block is properly positioned and attached to the femur, the tensioner applies force to the soft tissues while the position of the cutting block on the femur is established (e.g., either via a pin guide or drill guide, or directly based on linking the cutting block and the tensioner; either serves to constrain, at least partially, the placement of the cutting block. The linkage of whatever guide is used to the tensioner enables a known distance to be established and imparted by way of that linkage such that the guide is placed properly such that the cutting block is placed properly. In the case of linking the cutting block itself to the tensioner, the cutting block is positioned for an optimal desired cutting plane relative to the other patient anatomy and with the knee tensioned.

[0034] Typically, the extension space goal is to achieve equal gaps both medially and laterally between the femur and the tibia. The distance of the medial extension gap and the lateral extension gap may be based on the thickness(es) of the implants and/or various implant components to be used. In an aspect, following tibial resection and tensioner placement, the planned extension gaps may be calculated and/or set based on the thickness(es) of the femoral components and tibial components and the planned polyethylene insert thickness. In an example, the tibial baseplate is 4 mm thick, and a typical polyethylene thickness is 6 mm thick; the full tibial construct is therefore 10 mm thick in the example. Further, the implant thickness at the distal femur is 9 mm in the example. The total implant thickness to be inserted into the knee joint is therefore 19 mm thick (10 mm tibial construct and 9 mm distal femur thicknesses). Lastly, it is common to plan for 1 mm of additional “gap” in the total knee replacement. The target distance between the cut proximal tibia and the proposed distal femur cut therefore is to be 20 mm in this example (10 mm tibial construct, 9 mm distal femur thickness, and 1 mm of additional “gap”). If the joint were not tensioned before measuring the 20 mm from the tibial resection to place the femoral resection, then there is a risk that, once tensioned, the gap is not 20 mm - it is perhaps something more than 20 mm on account that the joint in tension repositions the femur significantly enough relative to the tibia. Tensioning the joint (to tension the soft tissues and therefore accurately reflect post-operative tensioning) is therefore desired before setting the femur cut location at the desired distance from the tibial cut.

[0035] A distal femoral cutting block may be placed/ slide over one or more pins (e.g., drill pins). Based on the known properties of the guides being used, various distances between guide features may be readily determined. This can inform where certain guide features (like pin holes) are to be positioned in order to properly position other features (such as a cut slot). Thus, a distance between the pin(s) and the proposed distal femur cut (e.g., between the pin and a slot in the cutting block through which a blade of a cutting tool enters to make the proposed distal femur cut) is a known or readily determinable distance based on the physical properties of the cutting block. In an aspect of the workflow described herein, the pin guide for placing the pin(s) is linked directly to the tensioner to provide a known, fixed distance from a bottom of the tensioner (which is in contact with the cut surface of the tibia) to portions of the pin guide, for instance hole locations of the pin guide. Using these known values, the relationship between pin placement and the desired bone cut can be reliably and/or reproducibly calculated. For example, the distance from the bottom of the tensioner to the proposed distal femur cut (or hole and/or slot in the cutting block for making the proposed distal femur cut) can be used in conjunction with the distance between the bottom of the tensioner and at least one pin (or hole in the cutting block for receiving a drill pin) to reliably and accurately determine the distance from the bottom of the tensioner to the desired location for that proposed distal femur cut and to inform proper placement of the guide(s) involved. For instance, subtracting (i) a distance between a drill pin and the proposed distal femur cut from (ii) the distance from the bottom of the tensioner to the proposed distal femur cut is equal to (iii) the distance to be provided between the drill pin and the bottom of the tensioner. These aspects are further discussed herein and with reference to FIGS. 4A-4C.

[0036] For example, the tensioner, when inserted into the knee joint after the tibial resection, may be placed on the surface of the cut tibia, and the soft tissues may be tensioned. Then, based on the known distance from the bottom of the tensioner to holes in the cutting block, (e.g., fixation holes and/or alignment holes configured to receive pins or other means to align and/or fix the cutting block with respect to the bone) with all sizes, shapes and connections being known distances and rigid structures, the system can be built to guide a pin placement whilst the tensioner is tensioning the soft tissues and the pin guide is physically linked to the tensioner at a known distance.

[0037] The physical linking forces a known spatial relation (for instance set, selected distances) between a tensioner point and points of the guide. In some embodiments, the link may force a spatial relation between a tensioner point and one or more points of a pin guide. This allows for the pins to be placed exactly where desired based on where the pins need to be according to the properties of the cutting block and where the cut slot thereof is to be positioned to accomplish the desired resection. The cutting block is then placed over the pins correctly placed and the distal femur cut will be made a desired distance (e.g., for instance 20 mm in non-limiting examples discussed herein) between the cut tibia and the cut distal femur on both the medial and lateral sides. In other embodiments, there may be no pin guide, and the link may force a spatial relation between a tensioner point and points of the cutting guide and/or block such that positioning the cutting block will result in a desired (e.g., 20 mm) distance between the cut tibia and the cut distal femur on both the medial and lateral sides. The specific distances used in examples herein are included for clarification of the principles underlying the instant disclosure, and are not meant to be limiting. These distances may vary depending on the implants and surgical systems used, among other considerations, and can have variable target distances manufactured. In an aspect, these distances may be set and modified during surgery based on surgeon preference and/or surgical goals. [0038] FIGS. 4A-4B show an example of a patient’s femur 400 and tibia 410. In an embodiment shown in FIG. 4A, a pin guide 415 is shown after being positioned on the femur 400. The pin guide 415 includes two pin holes 416a, 416b for receiving pins that will ultimately be used in placing a cutting block (shown in FIG. 4B as 420) on the femur 400. The pin guide 415 might include other features, not shown. Also, in the example, a tensioner 430 is shown tensioning an extension space 450 between the femur 400 and the tibia 410. A link and/or linking device 440 is shown connecting the tensioner 430 to the pin guide 415 in accordance with aspects herein. The connection(s) between the pin guide 415, the tensioner 430 and/or the linking device 440 may be facilitated by a fixation means, for example, one or more screw(s) 444.

[0039] More specifically, the linking device 440 may connect (e.g., fixedly and/or rigidly, or substantially fixedly and/or substantially rigidly) a bottom and/or base 432 of the tensioner 430 (e.g., a surface of the tensioner 430 that is abutting the tibia 410) to the pin guide 415. By way of the linking device fixing the location of the pin guide 415 relative to the bottom 432 of the tensioner 430, the linking device 440 imports a novel measuring function into the system, allowing for accurate measurements / distances to be provided between the connected elements, for example a distance from the bottom 432 of the tensioner 430 (which is representative of where the tibial implant will abut the tibia 410) to either of the pin holes 416a, 416b.

[0040] Even more specifically, a distance DI (vertical distance in this example) is shown between pin hole 416a of the pin guide 415 and a proposed and/or desired location of a cutting slot 424 of a cutting block 420 (FIG. 4B) to be placed over a pin that is ultimately inserted into the pin hole 416a. The desired location for the cutting slot 424 is shown in FIG. 4A by a hashed line, and the cutting slot 424 itself is shown in FIG. 4B. The distance DI is a known distance representing an offset of (i) the cut slot for the desired cut location from (ii) the pin hole 416a. Said differently, DI represents a difference between two distances shown in FIG. 4A as D2 and D3. Distance D2 is a distance between the bottom 432 of the tensioner 430 and the pin hole 416a, which may be known or readily determined. For instance, a process can determine a desired distance D3 to provide between the tibial and distal femoral resections for the extension gap 450 (e.g., 20 mm). Based on properties of the cutting block to be used, that is, the relative positioning between the pin hole of the cutting block and the cut slot of the cutting block, distance DI can be determined. D2 can then be determined by taking the difference between DI and D3, which then informs pin hole placement. The proper positioning for the pin guide to provide these proper pin locations can then be determined to inform the properties for the link 440 to use, for instance the distance (D2) that the link should provide when the pin guide is attached to the tensioner so that the pin guide is placed where shown in FIG. 4A. This guides proper pin placement by way of the pin guide, which results in the cutting slot 424 being aligned with a desired location for a bone cut (e.g., a location which results in a 20 mm extension gap, as an example), as shown in FIG. 4B. For clarity, the distance D3 which is desired for the extension gap 450 when the joint is in tension (e.g., the space in which an implant will ultimately be inserted) is the same as a distance between the desired location of the cutting slot 424 and the bottom 432 of the tensioner 430, because these locations represent opposite points about the extension gap 450 following the distal femoral resection.

[0041] FIG. 4B shows the knee without the tensioner inserted. The extension gap 450 shown in FIG. 4B may therefore have a different (shorter) length than the distance D3 of the extension gap 450 as shown in FIG. 4A, which is with the knee in tension. That is, without the tensioner 430, soft tissues of the joint are expected to relax (e.g., untense) which causes the femur 400 and the tibia 410 to move closer to each other. However, if the process as described above is followed in which the tensioner is inserted to tension the knee, then when the proper guides are used with proper linkage to achieve the desired distance between the tibial resection (via the bottom surface of the tensioner) and the cut slot, the extension gap 450 will be in condition to receive one or more implants and/or implant components following the distal femur cut as planned. The tensioner, when inserted (not shown in FIG. 4B) will tension the extension gap 450, maintaining and/or establishing the natural and/or pre- arthritic anatomic tensioning of the soft tissues for the patient’s post-operative joint.

[0042] For illustrative purposes, the example in FIGS. 4A-4B may be part of a surgical procedure requiring a 20 mm extension gap 450 distance D3. In such an example, the distance DI between the pin hole 416a and the slot 424 is 2 mm, and therefore the distance D2 between the pin hole 416a and the bottom 432 of the tensioner 430 must be 18 mm. As noted above, by subtracting the distance DI (2 mm) from the desired extension gap D3 (20 mm), it can be determined that a pin must be placed into the pin hole 416a at a distance D2 (18 mm) from the bottom 432 of the tensioner 430. The linking device 450 then, by virtue of fixedly and/or rigidly connecting the tensioner 430 to the pin guide 415, allows for the process to ensure an 18 mm distance D2 between the pin hole 416a and the bottom 432 of the tensioner 430 when the soft tissues of the joint are being tensioned to guide an accurate pin placement. The calculations used with respect to 416a are equally applicable with respect to 416b.

[0043] In this way, as a result of the proper placement of pins 422a, 422b using the pin holes 416a, 416b in accordance with aspects just described, the process ensures that the cutting block 420, and thus the cutting slot 424, is correctly positioned and/or aligned with the femur 400 for the performance of the distal femur cut. In the example, the cutting slot 424 is positioned such that the distal femur cut will result in the desired extension gap 450 distance D3 of 20 mm. Notably, in some embodiments the tensioner 430 may be (but does not have to be) removed along with the link 440 prior to the cutting block 420 being placed over the pins 422a, 422b, as shown. This is because the positioning of the pins 422a, 422b has already been established using the pin guide 415 such that placing the cutting block 420 on the femur 400 is ensured to result in the correct alignment of the cutting slot 424 with respect to the desired location of the bone cut (e.g., a location which will result in a desired extension gap 450 distance D3).

[0044] FIG. 4C shows an alternative embodiment of the process(es) described herein. Shown again in FIG. 4C is a patient’s femur 400 and tibia 410. In the example, a distal femoral cutting block 420 is shown after being positioned on the femur 400 using two pins 422a, 422b (422a and 422b identify both the pins and the corresponding holes in the cutting block 420 which receive the pins). The distal femoral cutting block 420 includes a hole and/or slot 424 for receiving a blade of a cutting tool (not shown) to make the distal femur cut, and therefore is to be positioned in alignment with the proposed and/or desired location of the distal femur cut. Also in the example, a tensioner 430 is shown tensioning an extension space 450 between the femur 400 and the tibia 410. A link and/or linking device 440 is shown connecting the tensioner 430 directly to the cutting block 420 (as opposed to a pin guide as in the example above) in accordance with aspects described herein and to provide the desired distance/spatial relation between the cutting block 420 and the tibial shelf as measured from the bottom of the tensioner. The connection(s) between the cutting block 420, the tensioner 430 and/or the linking device 440 may be facilitated by a fixation means, for example, one or more screw(s) 444.

[0045] More specifically, the linking device may connect (e.g., fixedly and/or rigidly, or substantially fixedly and/or substantially rigidly) a bottom 432 of the tensioner 430 (e.g., a surface of the tensioner 430 that is abutting the tibia 410) to the cutting block 420. By way of the linking device 440 fixing the location of the cutting block 420 relative to the bottom 432 of the tensioner 430, the linking device 440 imports a novel measuring function into the system, allowing for accurate measurements to be taken and/or distances to be determined from the bottom 432 of the tensioner 440 (which is representative of where the tibial implant will abut the tibia 410) to either of the pins and/or pin holes 422a, 422b and/or to the slot 424 for receiving a blade when cutting the distal femur (which is representative of the proposed distal femur cut and/or where the femoral implant will abut the femur 400).

[0046] The embodiment shown in FIG. 4C could rely on one or more of the distances described above with respect to FIGS. 4A-4B (e.g., considering distances DI and D2 to calculate a pin placement), though proper cutting block placement could be achieved in other ways. For instance, in the embodiment of FIG. 4C, the primary goal may be to link the cutting block 420 and the bottom 432 of the tensioner 430 (via the linking device 440) such that a distance between the bottom 432 of the tensioner 430 and the cutting slot 424 of the cutting block 420 is equal to the distance (D3) desired for the extension gap 450. As noted above, the distance D3 which is desired for the extension gap 450 is the same as a distance between the desired location of the cutting slot 424 and the bottom 432 of the tensioner 430, because these locations represent opposite points about the extension gap 450 following the distal femur cut.

[0047] For illustrative purposes, the example in FIG. 4C may be part of a surgical procedure requiring a 20 mm extension gap, and thus D3 equals 20 mm in the example. The linking device 440 may be configured such that connecting the tensioner 430 to the cutting block 420 results in a 20 mm distance between the bottom 432 of the tensioner 430 and the cutting slot 424 of the cutting block 420. Since the properties of the cutting block are known, an appropriate link could be selected to use to achieve the desired location for the cut slot. Then, with the cutting block 420 connected to the tensioner 430 by the linking device 440, the pins 422a 422b may be inserted to secure the cutting block 420 to the femur 400 such that the cutting slot 424 is properly aligned with the desired location for the bone cut (e.g., such that the cutting slot 424 is the correct distance D3 from the bottom 432 of the tensioner 430 when the soft tissues are being tensioned). In this way, the use of the linking device 440 to directly connect the cutting block 420 and the tensioner 430 (e.g., while the tensioner is tensioning the soft tissues of the joint) may avoid the need to undertake calculations that account for pin guide or drill guide placement to achieve desired pine placement for another guide (cutting block) with its own properties and cut slot location, for instance as was described above using distances DI and D2 when selecting and/or configuring the linking device 440 to guide a pin placement. In this manner, an embodiment connects the cutting guide 420 to the tensioner 430 to rigidly connect the cutting guide 420 to the tensioner based on the distance D3 between a desired location of the bone cut and a portion of the tensioner 430 that abuts the tibia 410 based on the tensioner 430 being inserted into the joint and tensioning the soft tissues thereof.

[0048] Relatedly, in the example shown in FIG. 4C, the distance between the pin 422a and the cutting slot 424 is 2mm, and therefore the distance between the pin 422a and the bottom 432 of the tensioner 430 must be 18 mm - the same as in the example of FIGS. 4 A and 4B. Thus, if desired, the process could utilize the same calculations as in FIGS. 4A and 4B, perhaps as a check to ensure the cutting block 420 has been properly placed and/or that the cutting slot 424 is properly aligned, but the desired distance D3 for the extension gap 450 (e.g., between the bottom 432 of the tensioner 430 and the cutting slot 424 of the cutting block 420) may be readily established by the linking device 440 absent such calculations.

[0049] Similarly to the process shown in FIGS. 4A-4B, the tensioner 430 may be removed from the joint following the placement of the cutting block 420, which may result in the soft tissues of the joint relaxing (e.g., untensing) and thus the femur 400 and the tibia 410 to move with respect to each other about the extension gap 450. However if the process as described above is followed correctly, the extension gap 450 will be in condition to receive one or more implants and/or implant components following the distal femur cut, which when inserted (not shown) will re-tension the extension gap 450 to the desired distance D3, maintaining and/or establishing the natural and/or pre-arthritic anatomic tensioning of the soft tissues of the patient’s joint following surgery.

[0050] In an aspect, the femoral component flexion is accounted for in the trajectory of the pins during pin placement. This may be either static or adjustable to accommodate surgical preference. The slope in the sagittal plane that is cut into the proximal tibia may be linked to and may impact the femoral component flexion. As part of the workflow disclosed herein, the slope of the sagittal plane that is cut into the proximal tibia may be built into the cutting guide for the femoral preparation or may be made to be adjustable based on surgeon preference and/or surgical goals.

[0051] In examples, the workflow is used without a robotic system. The order in which some aspects described herein are to be completed relative to other aspects described herein may be important in order to successfully utilize a tensioner with universal instrumentation.

[0052] (1) Initially, the process includes standard pre-operative total knee arthroplasty (TKA) steps (e.g., pre-operative imaging, patient testing and preparation, etc.), including total knee replacement exposure.

[0053] (2) A process for the tibial resection is then performed. For instance, this can be done at 0 degrees coronal alignment for neutral mechanical alignment workflows. Alternatively, anatomic tibial resection can be performed based on the amount of wear of the proximal tibia. There are cutting jigs with reference tools to identify different proximal tibial points. These jigs then help set the position of the drill guide(s), pin guide(s), cutting guide(s) and/or cutting block(s).

[0054] FIG. 1 shows example cartilage wear levels of the proximal portion of a patient tibia. The amount of wear can be determined using any desired approach. In FIG. 1, 104a and 104b correspond to medial and lateral cartilage on the proximal portion of patient tibia 102. Referring to the medial cartilage, point A indicates a normal cartilage (for instance 0 millimeters (mm) of wear), point B indicates mild wear (for instance 1 mm of wear), and point C indicates full wear (also referred to as “tidemark”, for instance 2 mm of wear). The tidemark is the point at which the cartilage is fully worn through to the underlying bone, and it is assumed that if the tidemark can be identified, then this represents a specific (e.g., 2 mm) wear from normal anatomy.

[0055] A medial wear point and a lateral wear point are identified on the proximal tibia (at the medial and lateral sides thereof, respectively), and the amount of wear is recorded for each of the medial and lateral side. For instance, the amount of wear for each side will be indicated as an amount of wear corresponding to one of points A, B or C, as examples. These points can be determined in any location (e.g., anterior, posterior, medial or lateral tibia) on each half of the proximal tibia. These wear points are relevant for varus/valgus-related tibial resection planning, i.e., the side-to-side slope of the resection. Additionally, this workflow could incorporate changing/adjusting the posterior (front-to-back) slope of the tibial cut to match native anatomic slope of the tibia, i.e., the tibial slope, which is the angle of the cut approximately 90 degrees from the coronal (or frontal) plane.

[0056] The varus and valgus of the tibial resection jig can be adjusted to match patient anatomy. For instance, the varus and valgus may be changed to identify the amount of tibia that is to be cut medially and laterally to match the wear that was identified. Specifically, the amount of planned tibial resection (anatomic tibial resection) plus the amount of wear is equal to (e.g., matches) the thickness of the implant (baseplate and polyethylene) that is planned to be inserted.

[0057] It is noted that example processes discussed herein may perform the above before any other bony resection to the tibia or femur is performed.

[0058] By way of specific example to highlight aspects of the above, assume that the medial point is C (corresponding to tidemark, which is 2 mm in this example) and the lateral point (transition point) is A (normal, or 0 mm in this example). The medial tibial resection is to account for 2 mm of wear, and the lateral tibial resection is to match no wear (0 mm). Assume also that the tibial tray is 4 mm thick and the polyethylene insert is 5 mm thick. The varus in this case is adjusted until the amount of tibial resection is 7 mm on the medial side and 9 mm on the lateral side. This will result in a 9 mm gap on both sides (medial, lateral) to accommodate the 9 mm of total implant. Thus, the lateral tibial cut should be 9 mm and the medial tibial cut should be 7 mm. The varus of the tibial resection jig is adjusted until these numbers are obtained. The concept is that the amount of tibial resection is to match the implant that is put in. The amount of implant being put back in is to match the thickness of the normal (not worn) side.

[0059] FIG. 2 depicts an example varus adjustment for tibial resection planning, in accordance with aspects described herein. In this example, a base resection plan that does not account for a varus adjustment shows 4 mm medially Ml and 9 mm laterally L2. In the example, the tibia 202 is intended to be cut into 3 degrees of varus (204) to match the patient's anatomy, resulting in an adjusted resection plan of 7 mm medially M2 and 9 mm laterally L2. Additionally, a slope may be determined based on implant design. Example cruciate retaining implants favor a fixed (e.g., 5-degree) slope if keeping the posterior cruciate ligament (PLC), or 2 degrees of slope if the PCL is resected, though such slopes could be adjusted to match patient anatomy.

[0060] (3) Continuing, the process performs the tibial bone cut (e.g., resection) to resect a portion of the tibia.

[0061] At this point, and prior to insertion/use of a tensioner device to tense and/or tension (e.g., apply reproduceable force and/or stress to) the knee, the following aspects labeled 4 through 11 are performed. These aspects can be performed in any desired order relative to each other and prior to insertion/use of the tensioner. This is because the soft tissue envelope, the gaps, and/or the amount that the flexion space opens can change during the operation/surgical procedure, and thus they are moving targets. In order to accurately balance the knee, the following aspects (4-11) are to be performed before tensioner insertion/use, otherwise accuracy may be compromised.

[0062] (4) Remove/clean out medial meniscus.

[0063] (5) Remove/clean out osteophytes from the medial gutter. Osteophytes, or bone spurs, tension soft tissues. These are to be removed from the medial and lateral gutters since, if left, they will tension the medial collateral ligament (MCL), lateral collateral ligament (LCL), and capsule. An osteotome, for example, can be used to clear excess bone.

[0064] (6) Remove/clean out medial notch/PCL tenting bone. On the medial side of the notch, which is the lateral part of the medial femoral condyle, an osteotome (as an example) can be used to remove excess bone when it is present and tensioning the PCL.

[0065] (7) Remove/clean out posterior osteophytes that tension the posterior capsule on the medial side.

[0066] (8) Remove/clean out lateral meniscus.

[0067] (9) Remove/clean out osteophytes from the lateral gutter.

[0068] (10) Remove/clean out posterior osteophytes that put tension on the posterior capsule on the lateral side.

[0069] (11) Optional PCL resection - if the PCL is going to be sacrificed, this is to be performed before the tensioner is inserted/used because otherwise, if done after tensioner insertion/use, then the removal of the PLC could result in different flexion space measurements than those captured while the PCL was intact.

[0070] In embodiments, the prior discussed aspects can be completed before the tensioner is inserted and/or used, otherwise balance may be inaccurate. In embodiments, aspects (1) and (2) are to be performed prior to aspect (3), and aspects (4) through (11) are to be performed after aspect (3) and prior to tensioner insertion and/or use (12), as discussed below. Aspects (4) through (11) could be performed in any desired order relative to each other. Since the soft tissue envelope changes based on the removal of the structures noted above with respect to aspects (4) through (11), these can be performed before the tensioner is introduced and used for tensioning.

[0071] (12) Insert tensioner into the knee to be flush with the proximal tibia. The tensioner can be any of a variety of types, for instance mechanical (e.g., spring- loaded), electronic, digital, laminar spreader-based, variable force generating, and/or sensor-based (e.g., using pressure-sensors or other sensors driven by relevant metrics), among others. Any other method to tension the soft tissues using a tensioner can be used at this point.

[0072] (13) In any case, the process then tensions the extension space while the leg is held at full (e.g., 0 degrees) extension. In an aspect, a guide may then be connected to the tensioner. In one aspect, a pin guide or a drill guide may be connected to the tensioner, which may be used to place pins to receive or otherwise position the distal femoral cutting block. In another aspect, the cutting block for the distal femur resection is connected directly to the tensioner. Different distal femoral cutting blocks of varying thicknesses or distances may be selected and/or attached to the tensioner based on the desired degree of extension space, which can vary from patient-to-patient or based on surgeon preferences. There may further be a means, such as a device or component, configured to connect (e.g., detachably connect) the distal femoral cutting block to the tensioner. Based on extension space tibial cut, the tensioner will distract the soft tissues.

[0073] (14) Then, in an aspect in which a pin guide or drill guide is connected to the tensioner, pins may be placed or holes may be drilled to accept pins in anticipation of positioning the distal femoral cutting block on the femur. In such an aspect, the pin guide or drill guide is then removed, and the distal femoral cutting block is positioned (e.g., using the pins). In another aspect, the tensioner is connected directly to the distal femoral cutting block as described above and has been positioned on the distal femur. In either aspect, the distal femoral cutting block is then pinned in place or otherwise fixed relative to the distal femur. The knee is held in full extension for this, and the coronal alignment of the leg will be driven by the tensioner.

[0074] The positioning of the tensioner and/or the cutting block on the distal femur may then be clinically verified. In an example, the positioning of the cutting block is verified by analyzing adjacent anatomic structures and verifying that the placement is reasonable. In another example, extra-medullary guides may be placed to provide indicators of accurate placement of the cutting block. FIG. 3 A shows the arrangement in full extension from both a lateral view (300) and anteroposterior view (301). As shown, the tensioner 302 is inserted between the cut proximal end 303 of the tibia 304 and the distal end 305 of the femur 306. The cutting block 308, linked to the tensioner 302 by link 310, is placed and pinned for the distal femur cut.

[0075] The distance from the bottom or base of the tensioner (which rests flush with and/or on the proximal tibia) to where the distal femoral cut is made using the cutting block may be a known, desired distance determined by the surgeon or a surgical system. Surgeons may have different preferences based on, for example, the implant system or type used. For example, some surgeons may prefer an equal medial and lateral extension space distance. In an example, the femoral component is 9 mm thick, and the tibial component is 10 mm thick (4 mm metal tray and 6 mm poly insert). The entire knee replacement component (e.g., the femoral component thickness plus the tibial component (tray + insert) thickness) in the example is therefore 19 mm in extension. If the surgeon desires an additional 1 mm of “laxity,” the surgeon may determine the distance to be tensioned by the tensioner as 20 mm. The cutting block attached to the tensioner as described above may be selected and/or arranged based on the 20 mm gap desired to be tensioned. In a different example, a surgeon may determine the distance to be tensioned by the tensioner as 22mm, in which case a different distal femoral cutting block may be selected.

[0076] The angle at which the distal femoral cutting block may be connected to the tensioner from the sagittal (e.g., side) plane can be a set value or variable. In some embodiments, the distal femoral cutting block may be connected to the tensioner at a fixed angle, e.g., a 90-degree angle. In other embodiments, there may be an option to have the sagittal angle vary on a case-by-case basis based on surgeon preferences. The angle of the connection between the distal femoral cutting block and the tensioner dictates the amount of femoral flexion that is cut into the distal femur.

[0077] The sagittal angle is the angle of flexion of the femoral component in the sagittal plane (e.g., when viewed from the sagittal plane), relative to the tibial slope. The tibial slope is set in the prior steps of tibial preparation. Variable femoral component flexion may be required based on, for example, surgeon preference(s) and can be built into the system and/or workflow as needed. In an aspect, the pins can be placed to achieve femoral component flexion that matches the tibial slope. For example, if the tibial slope is cut at 5 degrees then the femoral flexion can be cut at 5 degrees flexion in the sagittal plane to match, or counter, the tibial slope such that the combined flexion of the femoral component and tibial slope is neutral (5 degrees posterior tibial slope countered by 5 degrees of femoral flexion). There can be either multiple holes in the pin guide to place the pins at different flexion angles or, alternatively, adjustable flexion angles may be built into the system and/or workflow.

[0078] The degree of flexion at which the leg is held at the time of connecting the distal femoral cutting block to the tensioner also impacts the amount of femoral component flexion that is cut into the distal femur. For example, if the leg is positioned such that the knee is slightly flexed, then more flexion can be cut into the knee as compared to when the knee is fully extended (e.g., 0 degrees of flexion). If the leg is positioned such that the knee is slightly hyperextended, then less flexion, or even extension, may be cut into the distal femur. There is a danger associated with cutting the knee while hyperextended, as there is a risk of cutting a “notch” into the distal femur which can cause a fracture. In an aspect, the amount of flexion in the leg is known at the time of connecting the distal femoral cutting block to the tensioner. An additional guide may be placed off the distal femoral guides that rests against the distal femur anterior cortex to prevent hyperextension and notching.

[0079] (15) Then with the cutting block secured and the tensioner removed, the distal femur may be cut.

[0080] In embodiments, aspects 13 through 15 are to be completed before the flexion space is tensioned (as described below in aspect 16). In order to accurately cut the anterior and posterior femur, and the chamfers, the distal femur is to first be cut (e.g., resected) in a multiple-cut cutting block scenario so that the multiple-cut cutting block can sit flush and parallel to the distal femoral cut. Then, after the distal femur has been cut, the flexion space can be tensioned and the multiple-cut cutting block applied to the cut distal femur.

[0081] (16) Thus, the process then tensions the flexion space. For instance, at 90 degrees (as an example) of flexion, the tensioner may be inserted into the knee, at which point pressure is applied to the soft tissue envelope. The positioning of the tensioner and/or the guide connected to the tensioner (e.g., the pin guide, the drill guide, or the cutting block) may be clinically verified. In addition to the clinical verification examples provided above, the positioning of the tensioner and/or guide may further be clinically verified by ensuring the tensioner is in the knee, under the condyles and functioning correctly to add tension, and that the guide is sitting flush against the femur. The pressure applied by the tensioner results in a distraction of the flexion space. Additionally, the femur can be lifted so that it is not over-compressing the tensioner, which may be especially important for patients with large legs. A distal femoral sizing device may be used to select the femoral component size (e.g., to select an implant of the correct size) before further cuts are made. The distal femoral sizing device may be anchored to the tensioner or, alternatively, may be used separately from the tensioner to select the appropriate femoral component size.

[0082] In an aspect, the tensioner may be linked to a guide (e.g., a pin guide, a drill guide, or a multiple-cut cutting block). In an aspect, the tensioner may be linked to a pin guide or drill guide. In such an aspect, the tension is applied to the knee and pins are placed or holes are drilled. The tensioner and guide may then be removed and the appropriate sized multiple-cut cutting block may be placed over the pins, after which the femur is cut. In another aspect, the pin guide or drill guide is not used, and the multiple-cut cutting block is linked directly to the tensioner and attached directly to the femur. After the multiple-cut cutting block has been attached, the tensioner may be removed and the femur may be cut.

[0083] In an aspect, the tensioner may then be reinserted to tension the flexion space with the knee joint at a 90 degree angle. Once the soft tissues are tensioned, preparations are made to place the guide on the surface of the cut distal femur. In an example, the tensioner is placed on the cut tibial surface to tension the flexion space. The thickness of the posterior condyles of the femoral component is known based on the implant system being used. Also known is the distance from the bottom of the tensioner to the guide holes in the pin guide for placing the pins over which the multiple-cut cutting block will ultimately be placed. The pins may then be placed, or holes drilled, whilst the tensioner tensions the soft tissues in anticipation of cutting the femur to achieve the desired flexion gaps.

[0084] Desired flexions gaps typically, though not always, are to match desired extension gaps. In an aspect, medial flexion and medial extension gaps may match exactly, but this is not necessary and there may be some variance between medial flexion and medial extension gaps. In addition, different goals may be set depending on the particular implant(s) used and surgeon preferences. In the example discussed above, the planned medial extension gap is 20 mm (4 mm tibial tray, 6 mm polyethylene insert, 9 mm distal femoral component, and 1 mm additional “gap”). In this example, the medial flexion space is planned to match the medial extension gap. Therefore, the distance from the cut posterior femur to the cut tibia needs to accommodate the planned gap and component thickness(es) (4 mm tibial tray, 6 mm polyethylene insert, 8 mm posterior femoral component thickness, and 1 mm additional “gap” for a total of 19 mm gap distance). The distance between the cut tibial surface and the cut posterior femoral surface needs to be 19mm. Some surgeons prefer asymmetric gaps (2mm larger gap on the lateral flexion space). Asymmetric gaps can be achieved with an additional cut guide or with adjustability in a single cut guide. In an aspect, once the pins are placed into the bone, the multiple-cut cutting block may be placed over the pins to prepare the femur. It may be possible to use a pin guide and place the cutting block over the pins as just described, or, alternatively, it may be possible to link or otherwise connect the actual multiple-cut cutting block to the tensioner, in which case the pin guide may be unnecessary.

[0085] In an aspect, the tensioner may be connected to a drill guide or pin guide used to set and/or place the pins over which the distal femoral cutting blocks or multiple-cut cutting blocks are placed. By linking the tensioner to a preparatory guide, such as a pin guide or drill guide, for instance, used to set the position of the cut guide, traditional and commercially available distal femoral and multiple-cut cutting blocks may be rapidly and efficiently integrated into the workflow of the instant disclosure as long as the preparatory guide is configured for and/or compatible with the linking to the tensioner. Alternatively, a cutting block may be configured to connect directly to the tensioner, in which case the preparatory guide may be omitted. In yet other aspects, entirely new distal femoral and/or multiple-cut cutting blocks may be constructed that link or otherwise connect directly to the tensioner.

[0086] The posterior, posterior chamfer, anterior, and/or anterior chamfer cuts of the TKA may be made to the femur by utilizing the multiple-cut cutting block. The multiple-cut cutting block may be set flush against the distal femur cut surface and then (17) pinned into place (to the distal femur) while the tensioner is distracting the flexion space. Alternatively, a drill guide block may be connected to the tensioner, and holes made in the distal femur or pins placed in the distal femur using the drill guide may be used to position the multiple-cut cutting block. Internal and external rotation of the hip can optionally be leveraged to put the medial and lateral ligaments on full stretch. It is possible to have equal flexion numbers or unequal flexion numbers based on, for example, surgeon preference and/or the tensioning device used. FIG. 3B shows an arrangement in 90 degrees flexion from both a lateral view (320) and anteroposterior view (322). The tensioner 302 is inserted between the cut proximal end of the tibia 304 and the posterior distal end of the femur 306, and the multiple-cut cutting block 312, linked to the tensioner by link 310, is placed against the distal femur cut surface and pinned for the anterior, posterior and/or chamfer cuts of the femur.

[0087] The distance from the bottom or base of the tensioner (which rests flush on the cut proximal tibia) to where the posterior femoral cut is to be made using the cutting block may be a known, desired distance which is determined by the surgeon or a surgical system. Surgeons may have different preferences based on, for example, the implant system used. For example, some surgeons may prefer an equal medial and lateral flexion space distance. In an example, the femoral component is 7 mm, and the tibial component is 10 mm thick (4 mm metal tray plus 6 mm poly insert). The entire knee replacement component (e.g., the femoral component thickness plus the tibial component thickness) in the example is therefore 17 mm in extension. If the surgeon desires an additional 1 mm of “laxity,” the surgeon may determine the distance to be tensioned by the tensioner is 18 mm. In the example, the cutting block attached to the tensioner as described above may therefore be selected based on the 18 mm gap desired to be tensioned.

[0088] Further, it is common for surgeons to prefer a slight increase in laxity or distance in the lateral flexion space as compared to the medial flexion space. The asymmetric or eccentric flexion space is commonly around 2 mm more in the lateral flexion space than the medial flexion space. A single multiple-cut cutting block may be configured to account for the optional increase in laxity. In some embodiments multiple cutting blocks may be produced to accommodate different soft tissue targets. For example, a surgeon may aim for equal medial and lateral flexion space distances, in which case the surgeon may select a multiple-cut cutting block configured to guide cuts to the femur to produce a 20 mm medial flexion space and a 20 mm lateral flexion space. In an alternative example, a surgeon who prefers a slight increase in laxity in the lateral flexion space may select a multiple-cut cutting block configured to guide cuts to the femur to produce a 20 mm medial flexion space and a 22 mm lateral flexion space.

[0089] Similarly, multiple drill guide blocks could be made for when pins or holes are used to connect the multiple-cut cutting block to the femur. Alternatively, a single drill guide block may be configured to accommodate both a symmetric flexion space and an asymmetric flexion space. For example, different holes in the same drill guide block could be configured to produce different gaps and/or flexion spaces. In further embodiments, the multiple-cut cutting block may be linked or otherwise directly connected to the tensioner, and the cuts may be made from the multiple-cut cutting block, without the use of a drill guide or pin guide.

[0090] A user, for instance the surgeon, can determine target(s), or technology such as a software surgical platform, can provide the target(s) based on preoperative data. Example preoperative data is data for phenotypes, medical comorbidities, body mass index, gender, and/or any other factors that may contribute to the generation of an optimal target. A goal may be to limit soft tissue releases and obtain the desired balance. In specific or common examples, the goal is set to 1 mm of laxity in extension on both the medial and lateral sides, equal medial collateral ligament tension in both flexion and extension, and 3 mm of laxity on the lateral side in flexion, to allow for femoral roll back. The tensioner-cutting block connection may allow for variable flexion space targets.

[0091] (18) The process continues with cutting the anterior and posterior femur in addition to chamfers, (19) trial with trial components, (20) patella preparation, (21), final component insertion, and (22) standard closure for total knee arthroplasty.

[0092] Accordingly, aspects above may include at least the following process activities, some but not all of which are to be performed in a specific order relative to others:

1. Exposure

2. Measurement of tibial wear. Utilize tibial wear to set coronal tibial alignment. Adjust alignment until resection matches tibial component thickness accounting for wear.

3. Perform anatomic tibial resection. Surgeon can determine what guardrails they would like to have, including, for instance, maximum amounts of varus.

4. Remove meniscus and osteophytes

5. Tension the extension space, then pin cutting block to the distal femur

6. Cut distal femur

7. Tension in the flexion space, then apply the multiple-cut block to the cut distal femur 8. Perform anterior, posterior and chamfer cuts of femur

9. Trial assess final balance graft

10. Insert components

11. Close

[0093] To maximize tensioner utilization in this workflow, a number of aspects discussed above can be performed before the tensioner is inserted. Favorable patient outcome may be heavily reliant on performance of described aspects in order(s) emphasized, and failure to complete such aspects in order(s) emphasized (e.g., aspects prior to tensioner insertion, for instance) could result in inaccurate data and inaccurate balance, as the soft tissue envelope can change based on the presence or absence of various anatomic structures. Thus, in one aspect, the soft tissue envelope is tensioned after tenting osteophytes, removing the meniscus, and performing the tibial resection. Additionally, the amount of wear can be measured on the proximal tibia and used as one metric by which the coronal alignment of the tibial resection is set. This allows the surgeon to resect only the exact amount of proximal tibia to match what would be resected in the absence of wear. This is called an anatomic tibial resection and is very reliable. Also, aspects described herein can utilize the tensioner to obtain maximum or desired stretch on the medial and lateral structures at 90 degrees and in extension. Thus, aspects described herein explicitly recognize and leverage both use of proximal tibia wear and the fact that the soft tissue envelope changes during an operation/surgical procedure in planning, setting, and making an anatomic tibial resection. Additionally, performance of the noted aspects prior to tensioner insertion/use is leveraged to produce more accurate tensioner data.

[0094] Tensioners are often used with a robotic or navigation platform. However, aspects described herein use a tensioner in a manner not reliant on such robotic or navigation system, and recognize the order in which to perform aspects described herein to successfully use a tensioner with manual and/or universal instrumentations for total knee replacement (i.e., without a robotic and/or navigation system).

[0095] Aspects of embodiments described herein may be incorporated in, performed by, and/or used by one or more computer systems, such as one or more computer systems that are incorporated into and/or in communication with a platform supporting surgical procedures. For instance, a computer system may be used to plan cuts and/or cut locations, set cut parameters, measure and/or assist in measuring anatomical distances, select and/or identify appropriate guide(s) based on a cut parameters or planning, and/or perform any other activity related to planning and/or performing a surgical procedure utilizing instrumentation and processes described herein, including aspects of methods that may be claimed herein.

[0096] Processes described herein, and/or aspects thereof, may be performed singly or collectively by one or more such computer systems. A computer system may also be referred to herein as a data processing device/system, computing device/system/node, or simply a computer. The computer system may be based on one or more of various system architectures and/or instruction set architectures.

[0097] FIG. 5 shows a computer system 500 in communication with external device(s) 512. Computer system 500 includes one or more processor(s) 502, for instance central processing unit(s) (CPUs). A processor can include functional components used in the execution of instructions, such as functional components to fetch program instructions from locations such as cache or main memory, decode program instructions, and execute program instructions, access memory for instruction execution, and write results of the executed instructions. A processor 502 can also include register(s) to be used by one or more of the functional components. Computer system 500 also includes memory 504, input/output (I/O) devices 508, and I/O interfaces 510, which may be coupled to processor(s) 502 and each other via one or more buses and/or other connections. Bus connections represent one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include the Industry Standard Architecture (ISA), the Micro Channel Architecture (MCA), the Enhanced ISA (EISA), the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI).

[0098] Memory 504 can be or include main or system memory (e.g., Random Access Memory) used in the execution of program instructions, storage device(s) such as hard drive(s), flash media, or optical media as examples, and/or cache memory, as examples. Memory 504 can include, for instance, a cache, such as a shared cache, which may be coupled to local caches (examples include LI cache, L2 cache, etc.) of processor(s) 502. Additionally, memory 504 may be or include at least one computer program product having a set (e.g., at least one) of program modules, instructions, code, or the like that is/are configured to carry out functions of embodiments described herein when executed by one or more processors.

[0099] Memory 504 can store an operating system 505 and other computer programs 506, such as one or more computer programs/applications that execute to perform aspects described herein. Specifically, programs/applications can include computer readable program instructions that may be configured to carry out functions of embodiments of aspects described herein.

[00100] Examples of VO devices 508 include but are not limited to microphones, speakers, Global Positioning System (GPS) devices, RGB, IR, spectral, and/or other forms of cameras, lights, accelerometers, gyroscopes, magnetometers, sensor devices configured to sense light, proximity, heart rate, body and/or ambient temperature, blood pressure, and/or skin resistance, registration probes, robotic tools, and activity monitors. An VO device may be incorporated into the computer system as shown, though in some embodiments an VO device may be regarded as an external device (512) coupled to the computer system through one or more VO interfaces 510.

[00101] Computer system 500 may communicate with one or more external devices 512 via one or more VO interfaces 510. Example external devices include a keyboard, a pointing device, a display, and/or any other devices that enable a user to interact with computer system 500. Other example external devices include any device that enables computer system 500 to communicate with one or more other computing systems or peripheral devices such as a printer. A network interface/ adapter is an example VO interface that enables computer system 500 to communicate with one or more networks, such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet), providing communication with other computing devices or systems, storage devices, or the like. Ethernet-based (such as Wi-Fi) interfaces and Bluetooth® adapters are just examples of the currently available types of network adapters used in computer systems (BLUETOOTH is a registered trademark of Bluetooth SIG, Inc., Kirkland, Washington, U.S.A.). [00102] The communication between I/O interfaces 510 and external devices 512 can occur across wired and/or wireless communications link(s) 511, such as Ethernetbased wired or wireless connections. Example wireless connections include cellular, Wi-Fi, Bluetooth®, proximity -based, near-field, or other types of wireless connections. More generally, communications link(s) 511 may be any appropriate wireless and/or wired communication link(s) for communicating data.

[00103] Particular external device(s) 512 may include one or more data storage devices, which may store one or more programs, one or more computer readable program instructions, and/or data, etc. Computer system 500 may include and/or be coupled to and in communication with (e.g., as an external device of the computer system) removable/non-removable, volatile/non-volatile computer system storage media. For example, it may include and/or be coupled to a non-removable, nonvolatile magnetic media (typically called a “hard drive”), a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and/or an optical disk drive for reading from or writing to a removable, nonvolatile optical disk, such as a CD-ROM, DVD-ROM or other optical media.

[00104] Computer system 500 may be operational with numerous other general purpose or special purpose computing system environments or configurations. Computer system 500 may take any of various forms, well-known examples of which include, but are not limited to, personal computer (PC) system(s), server computer system(s), such as messaging server(s), thin client(s), thick client(s), workstation(s), laptop(s), handheld device(s), mobile device(s)/computer(s) such as smartphone(s), tablet(s), and wearable device(s), multiprocessor system(s), microprocessor-based system(s), telephony device(s), network appliance(s) (such as edge appliance(s)), virtualization device(s), storage controller(s), set top box(es), programmable consumer electronic(s), network PC(s), minicomputer system(s), mainframe computer system(s), and distributed cloud computing environment(s) that include any of the above systems or devices, and the like.

[00105] Aspects of the present invention may be a system, a method, and/or a computer program product, any of which may be configured to perform or facilitate aspects described herein. [00106] In some embodiments, aspects of the present invention may take the form of a computer program product, which may be embodied as computer readable medium(s). A computer readable medium may be a tangible storage device/medium having computer readable program code/instructions stored thereon. Example computer readable medium(s) include, but are not limited to, electronic, magnetic, optical, or semiconductor storage devices or systems, or any combination of the foregoing. Example embodiments of a computer readable medium include a hard drive or other mass-storage device, an electrical connection having wires, random access memory (RAM), read-only memory (ROM), erasable-programmable read-only memory such as EPROM or flash memory, an optical fiber, a portable computer disk/diskette, such as a compact disc read-only memory (CD-ROM) or Digital Versatile Disc (DVD), an optical storage device, a magnetic storage device, or any combination of the foregoing. The computer readable medium may be readable by a processor, processing unit, or the like, to obtain data (e.g., instructions) from the medium for execution. In a particular example, a computer program product is or includes one or more computer readable media that includes/stores computer readable program code to provide and facilitate one or more aspects described herein.

[00107] As noted, program instruction contained or stored in/on a computer readable medium can be obtained and executed by any of various suitable components such as a processor of a computer system to cause the computer system to behave and function in a particular manner. Such program instructions for carrying out operations to perform, achieve, or facilitate aspects described herein may be written in, or compiled from code written in, any desired programming language. In some embodiments, such programming language includes object-oriented and/or procedural programming languages such as C, C++, C#, Java, etc.

[00108] Program code can include one or more program instructions obtained for execution by one or more processors. Computer program instructions may be provided to one or more processors of, e.g., one or more computer systems, to produce a machine, such that the program instructions, when executed by the one or more processors, perform, achieve, or facilitate aspects of the present invention, such as actions or functions described in flowcharts and/or block diagrams described herein. Thus, each block, or combinations of blocks, of the flowchart illustrations and/or block diagrams depicted and described herein can be implemented, in some embodiments, by computer program instructions.

[00109] Although various embodiments are described above, these are only examples.

[00110] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

[00111] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below, if any, are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of one or more embodiments has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain various aspects and the practical application, and to enable others of ordinary skill in the art to understand various embodiments with various modifications as are suited to the particular use contemplated.

Claims

CLAIMS What is claimed is:

1. A method for establishing placement of a guide, the method comprising: determining a bone cut to be made to a first bone of a joint as part of a surgical procedure; selecting a guide based on the determining; tensioning soft tissues of the joint using a tensioner inserted into the joint between the first bone and a second bone; connecting the guide to the tensioner; and positioning the guide on the first bone with the soft tissues tensioned by the tensioner.

2. The method of claim 1, wherein the joint is a knee joint, and wherein the tensioning tensions the knee joint in extension.

3. The method of claim 1, wherein the joint is a knee joint, and wherein the tensioning tensions the knee joint in flexion.

4. The method of any of claims 1-3, wherein the connecting the guide to the tensioner includes rigidly connecting the guide to the tensioner based on a determined first distance between a desired location of the bone cut and a portion of the tensioner that abuts the second bone of the joint based on the tensioner being inserted into the joint and tensioning the soft tissues.

5. The method of claim 4, wherein the guide is a pin guide or a drill guide including a guide hole, and wherein the rigidly connecting is further based on a determined second distance between the desired location and the guide hole of the guide.

6. The method of any of claims 4-5, wherein the positioning further comprises positioning the guide on the first bone based on the rigidly connecting the tensioner to the guide, and wherein the method further includes: inserting a pin in the first bone using the guide hole or drilling a drill hole into the first bone using the guide hole; and placing a cutting block against the first bone using the pin or the drill hole, wherein the placing aligns a cutting slot of the cutting block with the desired location of the bone cut.

7. The method of any of claims 1-3, wherein the guide is a cut guide, and wherein the connecting the guide to the tensioner includes rigidly connecting the tensioner to the cut guide based on a determined distance between a desired location of the bone cut and a portion of the tensioner that abuts the second bone of the joint based on the tensioner being inserted into the joint and tensioning the soft tissues.

8. The method of any of claims 7, wherein the cut guide is a multiple-cut cutting guide or a distal femoral cutting guide.

9. The method of any of claims 1-3, wherein the connecting the guide to the tensioner further comprises: determining a first distance between a desired location of the bone cut and a fixation hole of the guide when the guide is to contact the first bone; determining a second distance between the desired location and a portion of the tensioner that is to contacts the second bone of the joint based on the tensioner being inserted into the joint and tensioning the soft tissues.

10. The method of claim 9, wherein the connecting the guide to the tensioner further comprises: determining, based on the first distance and the second distance, a third distance between the fixation hole and the portion of the tensioner; and rigidly connecting the guide to the tensioner based on the determined third distance.

11. The method of claim 10, wherein the positioning the guide on the first bone positions the guide based on the connecting the guide to the tensioner, wherein the positioning provides a fixed distance between the fixation hole and the portion of the tensioner based on the tensioner being inserted into the joint and tensioning the soft tissues that is equal to the third distance.

12. A system for positioning a guide relative to patient anatomy, the system comprising: a tensioner configured to tension soft tissues of a joint based on insertion of the tensioner between a first bone and a second bone of the joint, the tensioner having a first contacting surface and a second contacting surface, the first contacting surface configured to contact the first bone and the second contacting surface configured to contact the second bone; a guide configured to establish a position of a bone cut to be made to the first bone as part of a surgical procedure; and a link configured to rigidly connect the tensioner to the guide.

13. The system of claim 12, wherein the link is further configured to rigidly connect the second contacting surface to the guide.

14. The system of any of claims 12-13, wherein the link is further configured to rigidly connect the tensioner to the guide based on a desired distance between at least a portion of the second contacting surface and a hole of the guide.

15. The system of any of claims 12-13, wherein a length of the link to connect the tensioner to the guide is selected based on a desired distance between at least a portion of the second contacting surface and the bone cut to be made.

16. The system of any of claims 12-13, wherein the guide is a first guide, and wherein the link is further configured to fix a position of a hole of the first guide relative to at least a portion of the tensioner based on the second contacting surface being rigidly connected to the first guide, such that connecting the first guide to the tensioner results, based on the tensioner being inserted into the joint and tensioning the soft tissues, in the hole being aligned with: a desired location of the bone cut; or a desired location of a fixation member to be received by a second guide.

17. The system of claim 16, wherein the second guide is a cut guide, and wherein the link is configured such that the connecting the guide to the tensioner results, based on the tensioner being inserted into the joint and tensioning the soft tissues, in the hole being aligned with the desired location of the fixation member.

18. An apparatus for placement of a guide on a bone as part of a surgical procedure, the apparatus comprising: a tensioner; and a guide rigidly connected to the tensioner, wherein the guide includes a pin guide, a drill guide, or a cut guide.