Distal femoral pin guide instrument and method for orthopedic knee surgery

Abstract

An orthopedic instrument includes an alignment guide and an anterior stylus. The alignment guide is configured to contact a distal condyle of a femur of a patient to align a distal cutting block. A plurality of shims are selectively installed on the alignment guide based on a desired extension gap. A method of surgically preparing a femur of a patient is also disclosed.

Description

Technical Field

[0001] This disclosure relates generally to orthopedic surgical instruments, and more specifically to surgical instruments for removing bone from a patient. Background Technology

[0002] Arthroplasty is a well-known surgical procedure that replaces a diseased and / or damaged natural joint with a prosthetic joint. For example, in total knee arthroplasty, a patient's natural knee joint is partially or completely replaced with a prosthetic knee joint or knee implant. To facilitate the replacement of natural joints with prostheses, orthopedic surgeons use a variety of orthopedic instruments, such as saws, drills, reamers, files, broaches, cutting blocks, drill guides, milling guides, and other surgical instruments.

[0003] In total knee arthroplasty (TKA), the femur and tibia of the patient's knee joint are removed to create a planar surface on which prosthetic femoral and tibial components are implanted, respectively. Traditional TKA involves determining the resection plane based on predetermined angles according to mechanical alignment or by using a balanced method of setting the resection plane based on ligament tension. More recently, kinematic alignment techniques involve determining the resection plane based on the patient's original pre-disease state of the knee joint.

[0004] In any such method, the patient's knee joint is analyzed, and the desired extension gap is determined with the patient's knee joint positioned in extension. With the knee joint in flexion, the cutting block can be positioned using an intramedullary rod for the femur and an extramedullary clamp for the tibia. Summary of the Invention

[0005] According to one aspect of this disclosure, an orthopedic instrument for surgical preparation of a patient's femur during orthopedic knee surgery includes a medial pin guide and a lateral pin guide. The medial pin guide has an elongated guide hole including a longitudinal axis extending in an anterior / posterior direction. The lateral pin guide has an elongated guide hole including a longitudinal axis extending in an anterior / posterior direction, parallel to the longitudinal axis of the elongated guide hole of the medial pin guide. The orthopedic instrument also includes a medial paddle and a lateral paddle spaced inferiorly from the medial and lateral pin guides. The medial paddle has an alignment surface extending parallel to the longitudinal axis of the elongated guide hole of the medial pin guide and configured to contact the medial distal condyle of the patient's femur. The lateral paddle member has an alignment surface that extends parallel to the longitudinal axis of the elongated guide hole of the lateral pin guide member and is configured to contact the lateral distal condyle of the patient's femur. The orthopedic instrument also includes an anterior stylus that extends upward away from the medial and lateral paddle members. The anterior stylus includes an alignment surface configured to contact the anterior surface of the patient's femur.

[0006] The front contact pin can be configured to rotate relative to the inner and outer paddle elements while remaining perpendicular to the inner and outer pin guides.

[0007] In one embodiment, the alignment surface of the front stylus extends perpendicular to both the longitudinal axis of the elongated guide hole of the inner pin guide and the longitudinal axis of the elongated guide hole of the outer pin guide.

[0008] Orthopedic instruments also include a femoral plateau, wherein both a medial paddle and a lateral paddle are formed within the femoral plateau. An anterior stylus may include a lower end fixed to the plateau and an opposing upper end, wherein an alignment surface of the anterior stylus is formed in its upper end.

[0009] In one embodiment, the femoral platform includes a pin receiving hole positioned between the medial paddle member and the lateral paddle member. In such an embodiment, the anterior stylus includes a pin extending posteriorly from its lower end, wherein such pin is received in the pin receiving hole of the femoral platform to removably secure the anterior stylus to the femoral platform.

[0010] The orthopedic instrument also includes a plurality of pads. The thickness of each of the plurality of pads differs from the thickness of at least some of the other pads. In one embodiment, each of the plurality of pads includes a locking mechanism that cooperates with locking mechanisms of an inner paddle and an outer paddle, such that each of the plurality of pads is configured to be individually coupled to both the inner and outer paddles. In another embodiment, each of the plurality of pads includes a locking mechanism that cooperates with locking mechanisms of one or both of the inner and outer paddles, such that each of the plurality of pads is configured to be individually coupled to one or both of the inner and outer paddles.

[0011] In one embodiment, the locking mechanism of each of the plurality of gaskets includes an arcuate track, and the locking mechanisms of the inner and outer paddle members include arcuate slots configured to receive the arcuate track of each of the plurality of gaskets.

[0012] In another embodiment, the locking mechanism of each of the plurality of gaskets includes a post, and the locking mechanisms of the inner paddle and the outer paddle include elongated holes configured to receive the post of each of the plurality of gaskets.

[0013] In another embodiment, the femoral platform of the orthopedic instrument has a medial arm and a lateral arm extending upward therefrom. A medial pin guide is fixed to the upper end of the medial arm, and a lateral pin guide is fixed to the upper end of the lateral arm.

[0014] According to another aspect, a method for surgically preparing the femur and tibia of a patient's knee joint during orthopedic knee surgery includes: with the patient's knee joint positioned in extension, determining (i) a desired medial extension gap, indicating the distance between the medial condyle of the patient's femur and the medial plateau of the patient's tibia, and (ii) a desired lateral extension gap, indicating the distance between the lateral condyle of the patient's femur and the lateral plateau of the patient's tibia. A medial shim having a thickness corresponding to the determined medial extension gap is selected from a plurality of shims of varying thicknesses and mounted onto the medial paddle of a femoral pin guide. A lateral shim having a thickness corresponding to the determined lateral extension gap is selected from a plurality of shims of varying thicknesses and mounted onto the lateral paddle of a femoral pin guide. With the patient's knee joint positioned in flexion, the femoral pin guide is positioned on the distal femur such that (i) a femoral pad mounted on the medial paddle of the femoral pin guide contacts the distal medial femoral condyle of the patient's femur, (ii) a femoral pad mounted on the lateral paddle of the femoral pin guide contacts the distal lateral femoral condyle of the patient's femur, and (iii) the anterior stylus of the femoral pin guide contacts the anterior surface of the patient's femur. With the femoral pin guide positioned on the distal femur of the patient, a pair of guide pins are installed into the distal femur of the patient.

[0015] The desired medial extension gap and the desired lateral extension gap can be determined by manipulating a ligament balancer to balance the patient's knee joint.

[0016] The desired medial extension gap and the desired lateral extension gap can be determined by mechanically aligning the patient's knee joint.

[0017] The desired medial extension gap and the desired lateral extension gap can be determined by assessing the amount of cartilage loss within the patient's knee joint.

[0018] In one implementation, after the installation pins are installed, a distal cutting block is mounted on the pair of guide pins. A distal resection of the patient's knee joint is then performed using the distal cutting block to produce a planar resection surface.

[0019] According to another aspect, a method for surgically preparing the femur and tibia of a patient's knee joint during orthopedic knee surgery includes: determining a desired extension gap, indicating the distance between the femoral condyle and the tibial plateau, with the patient's knee joint positioned in extension; selecting a shim of varying thickness from a plurality of shims having a thickness based on the determined extension gap, and mounting it onto the paddle of a femoral pin guide device; positioning the femoral pin guide device in flexion, then positioning it on the distal end of the patient's femur such that the femoral shim mounted on the paddle of the femoral pin guide device contacts the distal femoral condyle of the patient's femur; and, with the femoral pin guide device positioned on the distal end of the patient's femur, installing a pair of guide pins into the distal end of the patient's femur.

[0020] The desired range of motion can be determined by manipulating a ligament balancer to balance the patient's knee joint.

[0021] The desired extension gap can be determined by mechanically aligning the patient's knee joint.

[0022] The desired extension gap can be determined by assessing the amount of cartilage loss within the patient's knee joint.

[0023] In one implementation, after the installation pins are installed, a distal cutting block is mounted on the pair of guide pins. The distal end of the patient's knee joint is then removed using the distal cutting block to create a planar resection surface.

[0024] In one embodiment, the desired extension gap is the desired medial extension gap, which indicates the distance between the medial condyle of the patient's femur and the medial plateau of the patient's tibia. In such an embodiment, the selected shim is mounted on the medial paddle of the femoral pin guide device to contact the distal medial femoral condyle of the patient's femur.

[0025] In one embodiment, the desired extension gap is the desired lateral extension gap, indicating the distance between the lateral condyle of the patient's femur and the lateral plateau of the patient's tibia. In such embodiments, the selected shim is mounted onto the lateral paddle of the femoral pin guide device to contact the distal lateral femoral condyle of the patient's femur.

[0026] In one implementation, the selected gasket has a thickness corresponding to the determined extension gap.

[0027] The method may also include resecting the proximal end of the patient's tibia to remove a portion of the tibia with a thickness based on a determined extension gap. In such embodiments, the sum of the thickness of the resected portion of the patient's tibia and the thickness of the pad corresponds to the determined extension gap. Attached Figure Description

[0028] The specific implementation method refers to the following figures, in which: Figure 1 and Figure 2 This is a perspective view of a distal femoral pin guide device used for surgical preparation of the femur during orthopedic knee surgery. Figure 3 yes Figure 1 Exploded perspective view of the distal femoral pin guide device; Figure 4 This is a perspective view showing the spacer being assembled into the distal femoral pin guide device; Figure 5 This is a frontal view of the patient's knee joint before undergoing orthopedic knee surgery. Figure 6 This is a front view showing a distal femoral pin guide device mounted on the distal femur of the patient prior to performing a distal femoral resection. Note the patient's knee joint in... Figure 6 The figure shows a state of flexion; Figure 7 This is a side view showing a distal femoral pin guide device mounted on the distal femur of the patient prior to performing a distal femoral resection. Note the patient's knee joint in... Figure 7 The figure shows a state of flexion; and Figure 8 This is a perspective view showing a distal cutting block mounted on the distal end of the patient's femur and used during distal femoral resection. Note the patient's knee joint in... Figure 8 The figure shows a state of flexion. Detailed Implementation

[0029] While the concepts of this disclosure are readily available in various modifications and alternatives, specific exemplary embodiments thereof have been shown by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that this disclosure is not intended to limit the concepts to the specific forms disclosed, but rather, the object of the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

[0030] Throughout this specification, when referring to orthopedic implants and surgical instruments described herein, as well as the natural anatomy of a patient, terms indicating anatomical reference, such as anterior, posterior, medial, lateral, superior, inferior, etc., may be used. These terms have well-known meanings in anatomical studies and orthopedic surgery. Unless otherwise stated, these anatomical reference terms used in the written details and claims are intended to be consistent with their well-known meanings.

[0031] refer to Figures 1 to 4 A surgical instrument 10 in the form of a distal femoral pin guide device is shown for surgical preparation of the femur in a patient during orthopedic knee surgery. The distal femoral pin guide device 10 includes an alignment guide 12 and a removable anterior stylus 14. The distal femoral pin guide device 10 is used to position and install a pair of guide pins 110 during surgical preparation of the distal femur in a patient during knee replacement surgery (see [link to original text]). Figures 6 to 8 As will be discussed in more detail below, the installed guide pin 110 is used to position the distal femoral cutting block 112 (see below). Figure 8 This distal femoral cutting block is used to perform distal cutting on the patient's femur.

[0032] As in Figures 1 to 4 As can be seen, the alignment guide 12 of the distal femoral pin guide device 10 includes a pair of pin guides 20, 22, which are configured to guide the pair of guide pins 110 into the distal end 108 of the patient's femur 100 (see [link]). Figure 6 and Figure 7 The inner pin guide 20 has an elongated guide hole 24 defined therein. The guide hole 24 of the inner pin guide 20 has a longitudinal axis 28 extending in a front / rear direction. Similarly, the outer pin guide 22 has an elongated guide hole 26 defined therein. The guide hole 28 of the outer pin guide 22 includes a longitudinal axis 30 extending in a front / rear direction and parallel to the longitudinal axis 28 of the elongated guide hole 24 of the inner pin guide 20.

[0033] As in Figures 1 to 4 As can be seen, the alignment guide 12 includes a femoral platform 38 having a pair of paddle-shaped members 40, 42 formed therein. Pin guides 20, 22 are secured to the femoral platform 38 via a pair of arms 50, 52 extending upwards away from the platform 38. Specifically, the medial pin guide 20 is secured to the upper end of the medial arm 50, while the lateral pin guide 22 is secured to the upper end of the lateral arm 52. In this manner, the medial paddle-shaped member 40 is spaced apart from the medial pin guide 20 on its underside. Similarly, the lateral paddle-shaped member 42 is spaced apart from the lateral pin guide 22 on its underside.

[0034] If still Figures 1 to 4As can be seen, the paddle-shaped members 40 and 42 each include alignment surfaces 44 and 46, which are fixed relative to the pin guides 20 and 22, such that during use of the distal femoral pin guide device 10, the pin guides 20 and 22 are positioned in the desired location for placing the guide pin, and the paddle-shaped members 40 and 42 are positioned to contact the distal femoral condyle of the patient. In the exemplary embodiment described herein, the alignment surface 44 of the lateral paddle-shaped member 42 extends parallel to the longitudinal axis 28 of the elongated guide hole 24 of the medial pin guide 20, while the alignment surface 46 of the lateral paddle-shaped member 42 extends parallel to the longitudinal axis 30 of the elongated guide hole 26 of the lateral pin guide 22.

[0035] As described above, and as will be discussed in more detail below, the alignment surface 44 of the medial paddle member 40 is configured to face or abut against the medial distal condyle 102 of the patient's femur 100. As will be described in more detail below, in some cases, the alignment surface 44 may also include a pad facing the medial distal condyle 102 of the patient's femur 100 (and may be positioned to contact the medial distal condyle). Similarly, the alignment surface 46 of the lateral paddle member 42 is configured to face or abut against the lateral distal condyle 104 of the patient's femur 100. In some cases, the alignment surface 46 may also include a pad facing the lateral distal condyle 104 of the patient's femur 100 (and may be positioned to contact the lateral distal condyle).

[0036] As in Figure 1 As can be seen, the medial paddle member 40 and the lateral paddle member 42 extend parallel to each other in the anterior / posterior direction. Specifically, the longitudinal axis 54 of the medial paddle member 40 extends in the anterior / posterior direction and is parallel to the longitudinal axis 56 of the lateral paddle member 42, which also extends in the anterior / posterior direction. This arrangement allows the alignment surfaces 44, 46 of the paddle members 40, 42 to be positioned in the desired orientation for contacting the distal condyles 102, 104 of the patient's femur 100, respectively.

[0037] Refer again Figures 1 to 4 The anterior stylus 14 extends upward away from the femoral plateau 38 and thus away from the paddle-shaped members 40, 42 of the alignment guide 12. The anterior stylus 14 includes a lower end 62 fixed to the femoral plateau 38 and an opposing upper end 64. (As in...) Figure 1 , Figure 3 and Figure 7As can be best seen, the anterior stylus 14 has an alignment surface 66 formed in its upper end 64. This alignment surface 66 is arranged generally perpendicular to the longitudinal axes 28, 30 of the pin guides 20, 22 and the alignment surfaces 44, 46 of the paddles 40, 42. The anterior stylus 14 is configured to rotate relative to the medial paddle 40 and the lateral paddle 42 while remaining perpendicular to the medial pin guide 20 and the lateral pin guide 22. In this manner, the alignment surface 66 of the anterior stylus 14 can be positioned to contact the anterior surface 106 of the patient's femur 100 (see [link to original text]). Figure 7 In this manner, when the distal femoral pin guide 10 is positioned on the patient's femur 100, the anterior stylus 14 is used to position and hold the pin guides 20, 22 at a desired angle relative to the anterior surface 106 of the femur 100. This angle may be perpendicular to the anterior surface 106 of the patient's femur 100, or may flex or extend relative to the anterior surface 106 of the patient's femur 100, and thus affect the final sagittal angle of the femoral prosthesis implant component. In the exemplary embodiment described herein, the anterior stylus 14 is used to position and hold the pin guides 20, 22 such that when the distal femoral pin guide 10 is positioned on the patient's femur 100, their respective longitudinal axes 28, 30 are substantially perpendicular to the anterior surface 106 of the patient's femur 100. In doing so, the anterior stylus 14 may also function as an intramedullary foramen locator.

[0038] As described above, the anterior stylus 14 can be selectively removed from the alignment guide 12. Specifically, the femoral platform 38 includes a pin receiving hole 48 positioned between the inner paddle member 40 and the outer paddle member 42. The anterior stylus 14 includes a mounting pin 68 extending rearward from its lower end 62. This mounting pin 68 is received in the pin receiving hole 48 of the femoral platform 38 to removably secure the anterior stylus 14 to the femoral platform 38. In some embodiments, the surfaces of the mounting pin 68 and the platform 38 defining the pin receiving hole 48 may be embodied with locking features, such as tabs and correspondingly shaped slots, to retain the mounting pin 68 in the hole 48. As described above, when positioned in the pin receiving hole 48, the mounting pin 68 is rotatable relative to the femoral platform 38 and therefore relative to the paddle members 40, 42 along their longitudinal axes. In this manner, the anterior stylus 14 can rotate relative to the paddle members 40, 42 while remaining perpendicular to the pin guides 20, 22.

[0039] As described above, the distal femoral pin guide device 10 also includes a plurality of spacers 90. These spacers 90 are configured with different sizes (i.e., different thicknesses) to allow the surgeon to select the optimal mating option during surgery for pairing with the paddles 40, 42 of the alignment guide 12. For example, the spacers 90 of the distal femoral pin guide device 10 may be provided in sizes 1 (e.g., with a thickness of 1 mm), 2 (e.g., with a thickness of 2 mm), 3 (e.g., with a thickness of 3 mm), 4 (e.g., with a thickness of 4 mm), and 5 (e.g., with a thickness of 5 mm). Spacers 90 of additional sizes may also be provided to suit the needs of a given design of the distal femoral pin guide device 10.

[0040] Each gasket in the gasket 90 includes a locking mechanism 92 that engages with locking mechanisms 70, 72 of the alignment guides' paddles 40, 42, respectively. In the exemplary embodiment described herein, the locking mechanism 92 of the gasket 90 is embodied as an arcuate track 94 having a dovetail cross-sectional shape, and the locking mechanisms 70, 72 of the alignment guides' paddles 40, 42 are embodied as a pair of elongated arcuate slots 74, 76, respectively. Each of the elongated arcuate slots 74, 76 has a dovetail cross-sectional shape, its dimensions and shape configured to receive the arcuate track 94 of the gasket 90. Therefore, the track 94 is configured to slide into the slots 74, 76, such that the dovetail interface connects the gasket 90 to the paddles 40, 42. In another exemplary embodiment, the locking mechanism 92 of the gasket 90 is embodied as a post, and the locking mechanisms 70, 72 of the paddles 40, 42 of the alignment guides are embodied as a pair of vertical elongated holes extending through the paddles 40, 42. In such embodiments, the post is sized to press-fit into the elongated holes to engage the gasket 90 to the paddles 40, 42.

[0041] In the exemplary embodiments described herein, the gasket 90 is "general" (i.e., not side-specific). In other words, each gasket 90 may be coupled to either the inner paddle 40 or the outer paddle 42. However, in some embodiments, the gasket 90 may be side-specific and therefore specifically shaped to be coupled to one of the paddles 40, 42, rather than both.

[0042] As will be described in more detail below, during the surgical preparation of the distal 108 of the patient's femur 100, the surgeon positions the patient's knee joint in extension and determines a desired extension gap, which indicates the desired distance between one or both of the medial distal condyle 102 and the lateral distal condyle 104 of the patient's femur 100 and one or both of the medial plateau 122 and the lateral plateau 124 of the patient's tibia 120. It should be understood that the surgeon may make this determination before or after resection of the patient's proximal tibia to remove a portion of the tibia. The surgeon may then utilize a shim 90 having a size (i.e., thickness) corresponding to the determined desired extension gap on the medial and / or lateral sides of the patient's knee joint. In particular, the surgeon selects a shim 90 from a variety of sizes having a size (i.e., thickness) corresponding to the desired extension gap. It should be understood that the selected thickness of the shim and the thickness of the removed portion of the tibia together equal the desired extension gap. After selecting the pad 90, the surgeon can install the selected pad 90 on the corresponding paddle-shaped parts 40, 42.

[0043] During the procedure, the surgeon can use the distal femoral pin guide device 10 to prepare the distal end 108 of the patient's femur 100 to receive the prosthetic femoral component during orthopedic knee surgery. To this end, the surgeon can use the distal femoral pin guide device 10 to mount a pair of guide pins 110 onto the patient's femur 100, and then use the distal cutting block 112 to guide the bone saw blade 114 to make a distal cut on the distal end 108 of the patient's femur 100.

[0044] like Figure 5 As shown, during this type of orthopedic surgery, the surgeon first orients the patient's femur 100 and tibia 120 so that the patient's knee joint is positioned in extension. With the patient's knee joint positioned in extension, the surgeon can use any of a variety of known techniques to determine the desired extension gap on each side of the patient's knee joint (i.e., medial and lateral). In particular, as... Figure 5 As shown, a surgeon can use any of a variety of known techniques to determine the desired medial extension gap 132, which indicates the distance between the medial distal condyle 102 of the patient's femur 100 and the medial plateau 122 of the patient's tibia 120. A surgeon can also use any of these known techniques to determine the desired lateral extension gap 134, which indicates the distance between the lateral distal condyle 104 of the patient's femur 100 and the lateral plateau 124 of the patient's tibia 120.

[0045] In some cases, surgeons may remove a portion of the tibia by excising the proximal tibia before determining the desired extension gap. Therefore, the final extension gap can be based on distal femoral resection, proximal tibia resection, or a combination of both.

[0046] The specific techniques used by the surgeon to determine the desired medial extension gap 132 and the desired lateral extension gap 134 (where the patient's knee joint is positioned in extension) can be chosen based on the needs of a given surgical procedure or the preference of a given surgeon. Among other techniques, the surgeon may use a balancing method, in which the surgeon manipulates a ligament balancer to position the femur 100 and tibia 120 of the patient's knee joint based on ligament tension, and then measures (i) the distance between the medial distal condyle 102 of the patient's femur 100 and the medial plateau 122 of the patient's tibia 120, and (ii) the distance between the lateral distal condyle 104 of the patient's femur 100 and the lateral plateau 124 of the patient's tibia 120. As another example, the surgeon may use a kinematic alignment technique, in which the surgeon measures cartilage loss and / or other tissue loss within the patient's knee joint to position the patient's knee joint in a location representing the original pre-disease state of the patient's knee joint, and subsequently selects a pad based on the measured cartilage loss. It should be understood that any of these techniques may be performed using mechanical instruments, automated instruments, computer-assisted surgical systems, or any other type of instrument, system, or method routinely used by surgeons to determine the desired extension gap 132, 134 when the patient's knee joint is positioned in extension.

[0047] Once the surgeon has determined the desired extension gaps 132, 134 with the patient's knee joint positioned in extension, the surgeon then orients the patient's femur 100 and tibia 120 so that the patient's knee joint is positioned in flexion. With the patient's knee joint positioned in flexion, various resections are performed on the patient's femur 100 and tibia 120. The surgeon uses the distal femoral pin guide 10, along with other instruments, to surgically prepare the patient's knee joint for the desired extension gaps 132, 134 (as previously determined with the patient's knee joint positioned in extension). It should be understood that the distal femoral pin guide 10 is not fixed to the patient's femur 100 before the patient's knee joint is positioned in flexion, thus eliminating the cumbersome process of pinning conventional guides and / or cutting blocks in knee extension and then attempting to move such pinned instruments to knee flexion without changing their pinned position. Furthermore, the use of the distal femoral pin guide 10 allows the cutting guide to be positioned using extramedullary techniques rather than intramedullary techniques.

[0048] Based on the desired extension gaps 132, 134 (as previously determined by the surgeon with the patient's knee joint positioned in extension), the surgeon then installs any necessary shims 90 onto the alignment guide 12. Specifically, the surgeon selects an appropriately sized shim 90 for each of the paddles 40, 42 based on the previously determined desired extension gaps 132, 134. In particular, as... Figure 4 As shown, the surgeon selects a shim 90 with a size (i.e., thickness) corresponding to the desired extension gap 132, 134 on each side (i.e., medial and lateral) of the patient's knee joint and mounts it on the corresponding paddle members 40, 42. For example, if the surgeon previously determines that the medial side of the patient's knee joint has a desired extension gap 132 of 4 mm, the surgeon selects a shim 90 of size 4 (4 mm thick) and mounts it on the medial paddle member 40 of the alignment guide 12. Similarly, for example, if the surgeon previously determines that the lateral side of the patient's knee joint has a desired extension gap 134 of 2 mm, the surgeon selects a shim 90 of size 2 (2 mm thick) and mounts it on the lateral paddle member 42 of the alignment guide 12. It should be understood that if the surgeon previously determines that an increased extension gap is not required on either side (or both sides) of the patient's knee joint, the shim 90 is not mounted on the corresponding paddle members 40, 42. For example, if a surgeon has previously determined that the patient's knee joint has a desired extension gap of 2 mm on the medial side 132, but the patient's knee joint does not require an increased extension gap on the lateral side, the surgeon selects a size 2 (2 mm thick) shim 90 and mounts it on the medial paddle 40 of the alignment guide 14, but does not mount any shim 90 on the lateral paddle 42. It should be understood that the selected thickness of the shim, together with the thickness of the proximal portion of the removed tibia, equals the desired extension gap.

[0049] Once the surgeon has positioned the patient's knee joint in flexion and installed the selected pad 90 (if any) on both paddles 40, 42, the surgeon positions the assembled distal femoral pin guide 10 on the distal end 108 of the patient's femur 100, as follows. Figure 6 and Figure 7As shown. Specifically, the surgeon positioning instrument 10 positions the alignment surface 44 of the medial paddle 40 (including any shims 90 included therewith) to contact the medial distal condyle 102 of the patient's femur 100, the alignment surface 46 of the lateral paddle 42 (including any shims 90 included therewith) to contact the lateral distal condyle 104 of the patient's femur 100, and the alignment surface 66 of the anterior stylus 14 to contact the anterior surface 106 of the patient's femur 100. This positions the pin guides 20, 22 (and then ultimately the distal cutting block 112) at locations based on desired extension gaps 132, 134 (as previously determined when the patient's knee is positioned in extension), because the dimensions (i.e., thickness) of the installed shims 90 take into account the desired gaps 132, 134. Upon reaching such a position, the surgeon may apply light pressure on the anterior stylus 14 to confirm proper contact between the stylus 14 and the femur 100.

[0050] Once the surgeon is satisfied with the alignment of the alignment guide 12, the surgeon can fix the distal femoral pin guide device 10 to the distal end 108 of the patient's femur 10 by installing a pair of guide pins 110 through the guide holes 24 and 26 of the pin guides 20 and 22, respectively. With the guide pins 110 installed on the distal end 108 of the patient's femur 100, the surgeon removes the distal femoral pin guide device 10 and then installs the distal cutting block 112 on the guide pins 110, as shown. Figure 8 As shown. Similarly, as Figure 8 As shown, the surgeon can then use the distal cutting block 112 to perform a distal resection of the distal end 108 of the patient's femur 100. Specifically, the surgeon can advance the bone saw blade 114 of a surgical saw through the distal cutting slot 116 to engage the patient's femur 100 and manipulate the surgical saw to surgically form a planar distal resection surface of the patient's femur 100. The surgeon can then attach additional cutting blocks, such as a 4-in-1 cutting block (not shown), to the surgically prepared distal resection surface and subsequently perform additional resections, such as anterior cuts, posterior cuts, and a pair of bevel cuts. Once the anterior cut, posterior cut, and two bevel cuts have been made, the surgeon removes the 4-in-1 cutting block from the patient's femur and completes the orthopedic knee surgery.

[0051] It should be understood that the use of the distal femoral pin guide 10 allows the surgeon to transfer measurements (e.g., the desired extension gap) obtained with the patient's knee joint positioned in extension to the desired alignment of the distal cutting block 112 with the patient's knee joint positioned in flexion, without requiring the surgeon to position the block in extension and then maintain the block's alignment while moving the bone of the knee joint into flexion. It should also be understood that the distal femoral pin guide 10 can be embodied with other features to suit the needs of a given design. For example, the alignment guide 12 can be embodied with arms 50, 52 that pivot and / or rotate relative to the femoral plateau 38 to provide additional alignment flexibility. Furthermore, the distal cutting block 112 can be integrated into the design of the distal femoral pin guide 10.

[0052] Although the present disclosure has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be regarded as exemplary rather than limiting in nature. It should be understood that only exemplary embodiments have been shown and described, and all changes and modifications made within the substance of the present disclosure should be protected.

[0053] The methods, apparatus, and systems described herein possess numerous advantages due to their various features. It should be noted that alternative embodiments of the methods, apparatus, and systems of this disclosure may exclude all described features, but may still benefit from at least some of the advantages of such features. Those skilled in the art will readily conceive of their own implementations of the methods, apparatus, and systems described above, which may incorporate one or more features of the invention and fall within the spirit and scope of this disclosure as defined by the appended claims.

Claims

1. A plastic surgery instrument for use in surgical preparation of a patient's femur during orthopedic knee surgery, the plastic surgery instrument comprising: An inner pin guide having an elongated guide hole having a longitudinal axis extending in the front / rear direction. An outer pin guide having an elongated guide hole having a longitudinal axis extending in the front / rear direction, so as to be parallel to the longitudinal axis of the elongated guide hole of the inner pin guide. An inner paddle-shaped member, spaced below the inner pin guide, has an alignment surface extending parallel to the longitudinal axis of an elongated guide hole in the inner pin guide and configured to contact the medial distal condyle of the patient's femur. A lateral paddle-shaped member, spaced below the lateral pin guide, has an alignment surface extending parallel to the longitudinal axis of an elongated guide hole in the lateral pin guide and configured to contact the distal lateral condyle of the patient's femur. An anterior stylus extends upward away from the medial and lateral paddle members and has an alignment surface configured to contact the anterior surface of the patient's femur.

2. The orthopedic instrument according to claim 1, wherein the alignment surface of the anterior stylus extends perpendicular to both the longitudinal axis of the elongated guide hole of the inner pin guide and the longitudinal axis of the elongated guide hole of the outer pin guide.

3. The orthopedic surgical instrument according to claim 1 further includes a femoral plateau, wherein: The medial paddle-shaped member and the lateral paddle-shaped member are formed in the femoral plateau. The front stylus includes a lower end fixed to the platform and an opposite upper end, and The alignment surface of the front stylus is formed in the upper end of the front stylus.

4. The orthopedic instrument of claim 1, wherein the anterior stylus is rotatable relative to the inner paddle and the outer paddle.

5. The orthopedic surgical instrument according to claim 1 further includes a plurality of pads, wherein: Each of the plurality of gaskets has a thickness different from the thickness of at least some of the other gaskets in the plurality of gaskets, and Each of the plurality of gaskets includes a locking mechanism that cooperates with the locking mechanisms of the inner paddle and the outer paddle, such that each of the plurality of gaskets is configured to be individually connected to both the inner paddle and the outer paddle.

6. The orthopedic surgical instrument according to claim 1 further includes a plurality of pads, wherein: Each of the plurality of gaskets has a thickness different from the thickness of at least some of the other gaskets in the plurality of gaskets, and Each of the plurality of gaskets includes a locking mechanism that cooperates with a locking mechanism of one or both of the inner paddle and the outer paddle, such that each of the plurality of gaskets is configured to be individually coupled to one or both of the inner paddle and the outer paddle.

7. The orthopedic surgical instrument according to claim 6, wherein: The locking mechanism for each of the plurality of gaskets includes an arc-shaped track, and The locking mechanism of the inner paddle and the outer paddle includes an arcuate slot configured to receive the arcuate track of each of the plurality of pads.

8. The orthopedic surgical instrument according to claim 6, wherein: The locking mechanism of each of the plurality of gaskets includes a post, and The locking mechanism of the inner paddle and the outer paddle includes an elongated hole configured to receive a post of each of the plurality of gaskets.

9. The orthopedic surgical instrument according to claim 1 further includes a femoral plateau, wherein: The medial paddle-shaped member and the lateral paddle-shaped member are formed in the femoral plateau. The inner arm extends upward away from the platform. The inner pin guide is fixed to the upper end of the inner arm. The outer arm extends upward away from the platform, and The outer pin guide is fixed to the upper end of the outer arm.

10. A method for surgically preparing the femur and tibia of a patient's knee joint during orthopedic knee surgery, the method comprising: With the patient's knee joint positioned in extension, determine (i) a desired medial extension gap, indicating the distance between the patient's medial femoral condyle and the patient's medial tibial plateau, and (ii) a desired lateral extension gap, indicating the distance between the patient's lateral femoral condyle and the patient's lateral tibial plateau. Select a medial washer of varying thickness from a plurality of washers, having a thickness corresponding to the determined medial extension gap, and then mount the selected medial washer onto the medial paddle of the femoral pin guide device. From a plurality of pads of different thicknesses, select a lateral pad with a thickness corresponding to the determined lateral extension gap, and install the selected lateral pad onto the lateral paddle of the femoral pin guide device. With the patient's knee joint positioned in flexion, the femoral pin guide is positioned on the distal end of the patient's femur such that (i) a femoral pad mounted on the medial paddle of the femoral pin guide contacts the distal medial femoral condyle of the patient's femur, (ii) a femoral pad mounted on the lateral paddle of the femoral pin guide contacts the distal lateral femoral condyle of the patient's femur, and (iii) the anterior stylus of the femoral pin guide contacts the anterior surface of the patient's femur. With the femoral pin guide device positioned on the distal end of the patient's femur, a pair of guide pins are installed into the distal end of the patient's femur.

11. The method of claim 10, wherein determining the desired medial extension gap and the desired lateral extension gap comprises: Operate the ligament balancer to balance the patient's knee joint.

12. The method of claim 10, wherein determining the desired medial extension gap and the desired lateral extension gap comprises: Mechanically aligned with the patient's knee joint.

13. The method of claim 10, wherein determining the desired medial extension gap and the desired lateral extension gap comprises: Determine the amount of cartilage loss within the patient's knee joint.

14. The method of claim 10, further comprising: Install the distal cutting block onto the pair of guide pins, and The distal resection of the patient's knee joint is performed by using the distal cutting block to produce a planar resection surface.

15. A method for surgically preparing the femur and tibia of a patient's knee joint during orthopedic knee surgery, the method comprising: With the patient's knee joint positioned in extension, determine the desired extension gap, which indicates the distance between the patient's femoral condyle and the tibial plateau. Select a shim of varying thickness from a range of shims, choosing one with a thickness based on the determined extension gap, and then mount the selected shim onto the paddle of the femoral pin guide device. With the patient's knee joint positioned in flexion, the femoral pin guide is positioned on the distal end of the patient's femur such that the femoral pad mounted on the paddle-shaped part of the femoral pin guide contacts the distal femoral condyle of the patient's femur. With the femoral pin guide device positioned on the distal end of the patient's femur, a pair of guide pins are installed into the distal end of the patient's femur.

16. The method of claim 15, wherein determining the desired extension gap comprises: Operate the ligament balancer to balance the patient's knee joint.

17. The method of claim 15, wherein determining the desired stretch gap comprises: Mechanically aligned with the patient's knee joint.

18. The method of claim 15, wherein determining the desired extension gap comprises: Determine the amount of cartilage loss within the patient's knee joint.

19. The method of claim 15, further comprising: Install the distal cutting block onto the pair of guide pins, and The distal resection of the patient's knee joint is performed by using the distal cutting block to produce a planar resection surface.

20. The method of claim 15, wherein: Determining the desired extension gap includes: with the patient's knee joint positioned in extension, determining a desired medial extension gap that indicates the distance between the medial condyle of the patient's femur and the medial plateau of the patient's tibia. Selecting the shim includes: selecting a medial shim with a thickness corresponding to the determined medial extension gap from a plurality of shims of different thicknesses, and mounting the selected medial shim onto the medial paddle of the femoral pin guide device; and Positioning the femoral pin guide includes: positioning the femoral pin guide on the distal end of the patient's femur with the patient's knee joint positioned in flexion, such that the medial pad mounted on the medial paddle of the femoral pin guide contacts the distal femoral condyle of the patient's femur.

21. The method of claim 15, wherein: Determining the desired extension gap includes: determining the desired lateral extension gap with the patient's knee joint positioned in extension, the desired lateral extension gap indicating the distance between the lateral condyle of the patient's femur and the lateral plateau of the patient's tibia. Selecting the shim includes: selecting a lateral shim with a thickness corresponding to the determined lateral extension gap from a plurality of shims of different thicknesses, and mounting the selected lateral shim onto the lateral paddle of the femoral pin guide device; and Positioning the femoral pin guide device includes: positioning the femoral pin guide device on the distal end of the patient's femur with the patient's knee joint positioned in flexion, such that the lateral pad mounted on the lateral paddle of the femoral pin guide device contacts the distal femoral condyle of the patient's femur.

22. The method of claim 15, wherein selecting the gasket having a thickness based on the determined extension gap comprises: Select a gasket with a thickness corresponding to the determined expansion gap.

23. The method of claim 15, further comprising: The proximal end of the patient's tibia was excised to remove a portion of the patient's tibia with a thickness based on the determined extension gap, and The sum of the thickness of the removed portion of the patient's tibia and the thickness of the pad corresponds to the determined extension gap.

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