Partial knee implant and method for installing the same

Abstract

To provide a partial knee implant and a method for installing the same.SOLUTION: The present disclosure is a femoral preparation guide and a kit of surgical components related to the femoral preparation guide. The femoral preparation guide is for use on a condyle of a femur during a surgical procedure in which the condyle receives a femoral condyle implant. The femoral preparation guide includes a posterior portion for fitting over a posterior region of the condyle and a distal portion for fitting over a distal region of the condyle. The distal portion is angled relative to the posterior portion. The distal portion includes first and second resection slots for receiving cutting tools that provide two resections of the condyle. The first and second cutting slots are angled relative to each other.SELECTED DRAWING: Figure 1C

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of and priority to U.S. Provisional Application No. 62 / 970,621, filed February 5, 2020, and U.S. Provisional Application No. 62 / 706,370, filed August 12, 2020, each of which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates to implants and surgical methods, and more particularly to partial knee implants and methods for installing the same using instrumentation. [Background technology]

[0003] Individuals experiencing knee pain can find relief through partial or total knee replacement surgery, which replaces one or more portions of a person's anatomy with one or more implant components. The present disclosure is directed to solving and / or improving upon problems associated with current knee implants and methods of installing such knee implants.

[0004] The concept of unicompartmental knee arthroplasty (UKA) was designed to cause less trauma or injury than traditional total knee replacement by removing less bone and preserving most of the person's bone and anatomy. This concept also uses smaller implants, thereby preserving most of the person's bone, with the goal of returning them to normal function more quickly. UKA replacement involves replacing only one condyle of the knee. This is a good option for early cases of arthritis, where only one condyle (usually the medial one) is affected by the arthritic process. The advantage of this type of knee replacement is that it preserves the portions of the knee not affected by arthritis (e.g., surrounding soft tissue, cruciate ligaments, and the contralateral healthy condyle).

[0005] Initially, UKA was not always successful because implants were poorly designed, people requiring surgery were not thoroughly screened for suitability, and optimal surgical techniques were not developed. Progress has been made to improve implant design. Appropriate patient selection by following the indications / contraindications and successfully performing the surgical procedure are key factors in the success of UKA.

[0006] UKA is typically suitable for people with moderate joint disease caused by painful osteoarthritis or trauma, a history of failed surgical procedures, or poor bone density that precludes other types of knee surgery. Individuals who may not be candidates for UKA include: active or suspected infection in or near the knee joint; known sensitivity to device materials; bone infection or disease that would prevent a new implant from being supported or fixed to the bone; inflammatory arthritis; major deformities that could affect the mechanical axis of the knee; neuromuscular disorders that could impair motor control and / or stability; obesity, significant bone loss from the shin bone (tibia), or any neuromuscular disorder with a severe tibial deformity; recurrent subluxation of the knee; untreated damage to the patella and femoral joint; untreated damage to the contralateral or ipsilateral condyles of the knee that have not been replaced with a device; and / or knee ligament instability that would compromise the postoperative stability of UKA.

[0007] Potential advantages of UKA include smaller incisions, allowing surgeons to make smaller incisions because UKA implants are smaller than total knee replacements. This may lead to smaller scars. Another potential benefit is less postoperative pain because less bone is removed. Also, quicker surgery and a shorter recovery period may be the result of less bone being removed during surgery, which may result in less trauma to the soft tissues. Also, the rehabilitation process may be more progressive. More specific benefits of UKA include improved range of motion, reduced blood loss during surgery, reduced time spent in the hospital, and potentially reduced costs.

[0008] Two of the most important advantages of UKA, or partial knee replacement, are (1) that partial knee replacement subjects find the replaced knee feels more like the original, unreplaced knee compared to total knee replacement, and (2) that partial knee replacement leaves other options open for further advancements. By not replacing the rest of the knee with metal and plastic, partial knee replacement does not burn bridges when other options for arthritis in these areas exist within a few years. Summary of the Invention [Means for solving the problem]

[0009] According to some implementations, the present disclosure employs a surgical approach that first requires a tibial cut in knee flexion. The proximal tibial resection is performed in extension using an alignment system. In flexion, the femoral gap is measured before performing the distal resection in extension, which is when the gap balancing process used by the surgeon begins. Spacer blocks and shim buildup are used to ensure that the smallest tibial implant (e.g., 8 mm) fits into the flexion space. Once the flexion space is balanced and the minimum gap of 15 mm required for the entire system is achieved, the distal femur can be resected. In extension, the distal femur is resected using a spacer block system with modular sliding resection guide blocks (different cut levels in multiple blocks) to address the required correlation with the flexion space. The goal is to resect the distal femur sufficiently (or minimally) as needed to equalize the resulting extension gap with the measured resulting flexion gap and achieve a balanced knee. The next step is to complete the femoral resections and peg preparation using the multipurpose femoral preparation guide and trial femoral component. The final step is to complete the tibial preparation using a tibial template, which acts as a surgical guide for sizing the tibia and drilling the tibial peg holes. The trial femoral component and tibial template are then removed, and the final tibial baseplate, tibial insert, and femoral condyle implant are placed.

[0010] According to one implementation of the present disclosure, a femoral preparation guide is for use on a condyle of a femur during a surgical procedure in which the condyle receives a femoral condyle implant. The femoral preparation guide includes a posterior portion for fitting over a posterior region of the condyle and a distal portion for fitting over a distal region of the condyle. The distal portion is angled relative to the posterior portion. The distal portion includes first and second resection slots for receiving a cutting tool that provides two resections of the condyle. The first and second resection slots are angled relative to each other.

[0011] According to another implementation of the present disclosure, a femoral preparation guide is for use on a condyle of a femur during a surgical procedure in which the condyle will receive a femoral condyle implant. The femoral preparation guide includes a posterior portion for fitting over a posterior region of the condyle and a distal portion for fitting over a distal region of the condyle. The distal portion is angled relative to the posterior portion. The distal and posterior portions define an outer periphery. At least a portion of the outer periphery substantially matches a portion of the implant periphery of the femoral condyle implant to provide an indication of the position of the femoral condyle implant on the condyle when the femoral condyle implant is later installed on the condyle.

[0012] According to a further implementation of the present disclosure, a femoral preparation guide is for use on a condyle of a femur during a surgical procedure in which the condyle receives a femoral condyle implant. The femoral preparation guide includes a posterior portion for fitting over the posterior region of the condyle and a distal portion for fitting over the distal region of the condyle. The distal portion is angled relative to the posterior portion. The femoral preparation guide includes a chamfer resection slot on the distal portion for receiving a cutting tool that provides a chamfered surface on the condyle that is angled relative to both the posterior and distal portions. The femoral preparation guide also includes a guide hole for receiving a drill that creates a peg hole located on the chamfered surface of the condyle.

[0013] In another aspect, the present disclosure is a femoral preparation guide for use with a condyle of a femur during a surgical procedure in which the condyle receives a femoral condyle implant. The femoral preparation guide includes a posterior portion for fitting over a posterior region of the condyle. The posterior portion has an attachment element on an inferior aspect of the posterior portion. A distal portion of the guide fits over a distal region of the condyle. The femoral preparation guide further includes a shim coupled to the attachment element to provide adequate joint space to the tibia. The shim is selected from a plurality of shims of different sizes.

[0014] In a further aspect, the present disclosure is a femoral preparation guide for use on a condyle of a femur during a surgical procedure in which the condyle receives a femoral condyle implant. The femoral preparation guide includes a body for fitting over the top of the condyle. The body has a slot for guiding a resection cut in the condyle. The body has an outer periphery. At least a portion of the outer periphery substantially matches a portion of the implant periphery of the femoral condyle implant to provide an indication of at least one of (i) the medial-lateral position of the femoral condyle implant that will subsequently be placed on the condyle, or (ii) the size of the femoral condyle implant that will subsequently be placed on the condyle.

[0015] In yet a further aspect, the present disclosure provides a set of femoral preparation components for use on the condyles of the femur during a surgical procedure in which the condyles receive a femoral condyle implant. The femoral preparation components include a femoral preparation guide and a femoral trial guide. The femoral preparation guide has (i) a posterior portion for fitting over the top of the posterior region of the condyle, (ii) a distal portion for fitting over the top of the distal region of the condyle, (iii) at least one resection slot for receiving a cutting tool to provide a resection of the condyle, and (iv) a first guide hole for receiving a drill to create a first peg hole located on the condyle. The femoral trial guide is for placement on top of the condyle after the resection developed in the femoral preparation guide. The femoral trial guide includes a second guide hole for receiving a drill to create a second peg hole located on the condyle. The first and second peg holes are for receiving pegs of the femoral condyle implant.

[0016] In yet another aspect, the present disclosure is a set of femoral preparation components for use on the condyles of the femur during a surgical procedure in which the condyles receive a femoral condyle implant. The femoral preparation components include a femoral resection block, a femoral preparation guide, and a femoral trial guide. The femoral resection guide block slides over the top of a spacer component positioned in the area below the condyle. The femoral resection guide block includes a resection slot for receiving a cutting tool that provides a first resection of the condyle. The femoral preparation guide is for attachment to the condyle in the first resection area. The femoral preparation guide has two resection slots for receiving cutting tools that provide a second and third resection of the condyle. The femoral preparation guide includes a first guide hole for receiving a drill that creates a first peg hole located in the condyle. The femoral trial guide is for placement on top of the condyle after the resection developed in the femoral preparation guide. The femoral trial guide includes a second guide hole for receiving a drill that creates a second peg hole located in the condyle.

[0017] In another aspect, the present disclosure is a femoral trial guide for use on the condyles of a femur during a surgical procedure in which the condyles receive a femoral condylar implant. The femoral trial guide includes a curved outer surface that mimics the outer surface of the femoral condylar implant to provide an indication of the position and kinematics of the subsequently implanted femoral condylar implant. The femoral trial guide also includes a guide hole for receiving a drill that creates a peg hole located on the condyle.

[0018] The present invention also includes methods of using the femoral preparation components described below and kits of components described below.

[0019] The present invention also includes a kit of components for the tibial preparation described below.

[0020] The present invention further includes kits of components for tibial preparation, as described below, in combination with components for femoral preparation, as described below.

[0021] The foregoing and other advantages of the present disclosure will become apparent upon reading the following detailed description and upon reference to the drawings. [Brief explanation of the drawings]

[0022] [Figure 1A] 1 shows a knee undergoing a UKA procedure according to the present disclosure. [Figure 1B] 1B illustrates surgical components for installation in the knee of FIG. 1A according to the present disclosure. [Figure 1C] 1A shows the knee of FIG. 1A with the surgical components of FIG. 1B after implantation. [Figure 2] FIG. 1B shows the tibial baseplate of the system. [Figure 3] FIG. 1C shows the tibial insert of the system of FIG. 1B. [Figure 4] FIG. 1B shows the femoral condylar implant of the system. [Figure 5] 1 shows a tibial resection guide attached to the tibia. [Figure 6] Figure 5 shows the tibial resection guide being used to make two cuts into the tibia. [Figure 7] Figures 5-6 show two cuts in the tibial plateau obtained using the tibial resection guide. [Figure 8A] 1 shows a universal handle used to attach / remove multiple components in the system and to couple to measurement tools. [Figure 8B] Figure 8A shows the universal handle attached to a spacer for measuring the flexion gap between the resected tibia and femoral condyles. [Figure 9] 1 shows a universal handle attached to a spacer for measuring the extension gap between the resected tibia and the femoral condyle. [Figure 10] Figures 8-9 show the placement of the femoral resection guide block on top of the spacer. [Figure 11] Figure 10 shows a femoral resection guide block being used to make cuts in the femoral condyles. [Figure 12]1 shows a gap spacer for measuring the gap between the resected tibia and the resected surface of the femoral condyle. [Figure 13] FIG. 11 shows the femoral preparation guide attached to the resected femoral condyle created in FIG. [Figure 14] FIG. 14 shows the femoral preparation guide of FIG. 13 being used to create femoral peg holes with a drill. [Figure 15] 14 shows the femoral preparation guide of FIG. 13 being used to create a posterior resection. [Figure 16] 14 shows the femoral preparation guide of FIG. 13 being used to create a posterior chamfer resection. [Figure 17] Figures 11, 15, and 16 show three flat surfaces on the femoral condyle resulting from the cuts. [Figure 18] 10 shows the universal handle being used to attach the femoral trial guide. [Figure 19] 10 shows a femoral trial guide being used to create holes in the femoral condyles. [Figure 20] Shown is the resected tibial plateau being measured for the correct size of the final tibial baseplate and tibial surgical template. [Figure 21] Shown are tibial spacer bases and shims for measuring gap and soft tissue tension in flexion and extension. [Figure 22] 10 shows a tibial impactor being used to place a tibial surgical template on the resected tibial plateau. [Figure 23] 23 shows a tibial surgical template on the resected tibial plateau after the process of FIG. 22. [Figure 24] 1 shows a tibial surgical template and drill guide being used to create a hole in the resected tibial plateau. [Figure 25] 10 shows the tibial surgical template and tibial trial insert for testing the relationship with the femoral trial guide prior to installation of the final implant components. [Figure 26] 10 shows the tibial trial insert being removed from the tibial surgical template. [Figure 27] 10 shows the universal handle being used to remove the femoral trial guide. [Figure 28] Shown are the three resulting surfaces and femoral peg holes on the femoral condyle and the two resulting surfaces and tibial peg holes on the tibial plateau. [Figure 29] Figure 2 shows the tibial impactor being used to install the tibial baseplate. [Figure 30] Figure 4 shows the femoral impactor being used to install the femoral condylar implant. [Figure 31] 4 shows an insert impactor being used to install the tibial insert of FIG. 3. [Figure 32A] 14 illustrates the first femoral preparation guide of FIG. 13 in relation to a corresponding femoral condyle implant. [Figure 32B] 14 illustrates the second femoral preparation guide of FIG. 13 in relation to a corresponding second femoral condyle implant. [Figure 32C] 14 illustrates the third femoral preparation guide of FIG. 13 in relation to a corresponding third femoral condyle implant. [Figure 33A] 14 shows details of attachment of the femoral preparation guide of FIG. 13 to the femoral condyles. [Figure 33B] 14 shows details of attachment of the femoral preparation guide of FIG. 13 to the femoral condyles. [Figure 33C] 14 illustrates the use of the femoral preparation guide of FIG. 13 to help guide the drilling of the peg holes. [Figure 33D] 13 illustrates in more detail the use of the femoral preparation guide in creating the posterior resection. [Figure 33E] 13 illustrates in more detail the use of the femoral preparation guide of FIG. 13 in creating a posterior chamfer resection. [Figure 34A] 14 shows details of the femoral preparation guide of FIG. 13 for creating proper spacing for the tibial plateau. [Figure 34B]14 shows details of the femoral preparation guide of FIG. 13 for creating proper spacing for the tibial plateau. DETAILED DESCRIPTION OF THE INVENTION

[0023] While the present disclosure is susceptible to various modifications and alternative forms, specific implementations have been shown by way of example in the drawings and are described in more detail herein. It should be understood, however, that the present disclosure is not intended to be limited to the particular forms disclosed. Rather, the present disclosure is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure, as defined by the appended claims.

[0024] The present disclosure is described with reference to the accompanying drawings, in which like reference numerals are used throughout to indicate similar or equivalent elements. The drawings are not drawn to scale and are provided solely to illustrate the present disclosure. Several aspects of the present disclosure are described below with reference to illustrative example applications.

[0025] FIG. 1A illustrates a knee 10 undergoing a UKA procedure by performing surgical steps on the femur 12 and tibia 14. FIG. 1B illustrates the final surgical component system installed on the knee 10 of FIG. 1A in accordance with the present disclosure. The three components include a tibial baseplate 20, a tibial insert 30, and a femoral condylar implant 40. In FIG. 1C, the tibial baseplate 20, tibial insert 30, and femoral condylar implant 40 are shown on the tibia 12 and femur 14 after various procedures outlined in detail in FIGS. 5-34 below. The tibial baseplate 20 is mounted on the tibia 14. The tibial insert 30, which is a resilient material, fits within the tibial baseplate 20. The femoral condylar implant 40 is mounted on the femur 12 and engages with the tibial insert 30 by rolling over the top of the tibial insert 30 as the patient bends their knee.

[0026] FIG. 2 shows details of the tibial baseplate 20 of the system of FIG. 1B. The tibial baseplate 20 is D-shaped and includes a recess 22 in its upper portion. A pair of pegs 24 extend downwardly from the lower portion of the tibial baseplate 20. Although not shown in FIG. 2, a keel (i.e., an extended ridge) extends downwardly from the lower portion of the tibial baseplate 20 along the linear edge of the D-shaped tibial baseplate 20. In one preferred embodiment, the sizing and shaping of the tibial baseplate 20 are optimized according to a statistical shape model, with the medial left implant being a mirror image of the lateral right implant.

[0027] FIG. 3 shows a tibial insert 30 inserted into the recess 22 of the tibial baseplate 20 of FIG. 2. The tibial insert 30 includes a lower projection 32 that fits securely within the recess 22 of the tibial baseplate 20. A projection 34 extends horizontally from the lower projection 32 of the tibial insert 30 and engages a corresponding undercut in the tibial baseplate 20 to aid in retention on the tibial baseplate 20. The tibial insert 30 is made of a resilient material because it serves as the mating surface for the femoral condyle implant 40. The tibial insert 30 is provided in various thicknesses as part of a kit to help match the patient's anatomy, as selected by the surgeon. In one preferred embodiment, the tibial insert 30 is labeled with various thicknesses (e.g., 8 mm, 9 mm, 10 mm), which correspond to the combined thickness of the tibial baseplate 20 and the selected tibial insert 30.

[0028] FIG. 4 shows a femoral condylar implant 40 installed in the femur 14 of FIG. 1C. The femoral condylar implant 40 includes a rounded outer surface 42 that follows the curvature of the condylar bone being replaced. The underside includes a distal surface 44, a medial surface 46, and a proximal surface 48. The underside includes two pegs 49 extending from the distal surface 44 and the medial surface 46. In one preferred embodiment, the sizing and shaping of the femoral condylar implant 40 is optimized according to a statistical shape model, with the medial left implant being a mirror image of the lateral right implant.

[0029] The bone preparation and trialing steps taken prior to installation of the tibial baseplate 20, tibial insert 30, and femoral condylar implant 40 are generally described in connection with FIGS. 5-34.

[0030] To prepare the tibia 14, a tibial resection guide 50 is attached to the tibia 14 as shown in FIG. 5. The tibial resection guide 50 is initially held in place with the use of a distal body ankle clamp (not shown), which is secured to the patient's ankle region and includes arms extending toward the knee. This clamp preferably includes adjustment features that allow the tibial resection guide 50 to be adjusted in the medial-lateral (ML) and anterior-posterior (AP) directions to achieve the desired alignment on the tibia 14. The distal body ankle clamp holds the tibial resection guide 50 in place to provide the appropriate amount of bone removal from the tibia 14, as determined by the surgeon.

[0031] After being positioned for proper alignment, the tibial resection guide 50 is then secured to the tibia 14 by temporary pins extending through the holes 52 and 54 in the tibial resection guide 50. It also includes a curved portion 56 that extends partially around the tibia 14, similarly providing some lateral stability. The upper surface 58 includes a plurality of grooves 59 that provide alignment for the sagittal resection of the tibia. A saw may have a feature that fits within one of the grooves 59 to serve as a guide for a saw 60 that provides a sagittal resection of the tibia 14, as shown in FIG. 6. FIG. 6 also shows the upper surface 58 of the tibial resection guide 50 serving as a guide for a saw 62 that provides a transverse resection of the tibia 14.

[0032] Figure 7 shows the sagittal resection cut 72 and the transverse resection cut 74 in the tibial plateau resulting from use of the tibial resection guide 50 of Figures 5-6. Figure 7 also shows the pin holes 76 used to hold the tibial resection guide 50 to the tibia 14.

[0033] Figure 8A shows a universal handle 80 used to hold various components during the procedure. In Figure 8B, the universal handle 80 is attached to a spacer device 82 to measure the flexion gap between the transverse resection cut 74 and the corresponding condyle on the femur 12. In one embodiment, the flexion gap should be at least 8 mm. The flexion gap corresponds approximately to the combined thickness of the tibial baseplate 20 and tibial insert 30 (Figures 2 and 3).

[0034] In FIG. 9, a universal handle 80 is attached to a spacer device 82 for measuring the extension gap between the transverse resection cut 74 and the corresponding section of the condyle on the femur 12. The spacer device 82 may be the same spacer device as in FIG. 8A or may be a different spacer. The surgeon can use various spacers (e.g., 7 mm, 8 mm, 9 mm, 10 mm) to determine the most accurate measurements of both the flexion and extension gaps. The relative measurements of the flexion and extension gaps define the amount of femur to be resected.

[0035] FIG. 10 illustrates the placement of a resection guide block 100 that slides over the top of the spacer device 82 of FIG. 9. The resection guide block 100 is selected based on the relative measurements of the flexion and extension gaps. For example, if the flexion gap is measured as 8 mm and the extension gap is measured as 9 mm, a -1 mm distal resection guide 100 should be used to achieve a resulting extension gap of 8 mm. If the extension gap is measured as 7 mm, a +1 mm distal resection guide 100 should be used to achieve a resulting extension gap of 8 mm. While the universal handle 80 holds the spacer device 82 and the selected distal resection guide 100 steady, a pin 102 is inserted into the femur 12 to hold the distal resection guide 100 to the femur 12 while the knee is extended.

[0036] Figure 11 shows the selected distal resection guide 100 of Figure 10 after the pin 102 has been installed and the universal handle 80 has been removed. A resection saw 110 fits through the distal resection guide 100 and creates a transverse cut in the distal portion of the femoral condyle.

[0037] FIG. 12 shows a gap spacer block 120 for measuring the gap between the transverse resection cut 74 and the flat distal surface 122 created by the resection saw 110 of FIG. 11. The gap spacer blocks 120 are provided in multiple sizes, correlating with the thickness of the tibial construct plus the thickness of the femoral construct. Each gap spacer block 120 provides multiple thicknesses (e.g., two per paddle) representing combined thicknesses for the femoral condyle implant 40 (e.g., 7 mm) and tibial insert 30 (e.g., 8, 9, 10, and 12 mm). Thus, the system includes two gap spacer blocks 120, the first having thicknesses of 15 mm and 16 mm, and the second having thicknesses of 17 mm and 19 mm. Thus, if the selected femoral condyle implant 40 (FIG. 4) has a thickness of 7 mm on both the distal and posterior condyles, and the selected tibial insert 30 (with tibial baseplate 20) has a thickness of 8 mm, a gap spacer block 120 having a thickness of 15 mm should fill the gap in FIG. 12.

[0038] FIG. 13 shows a femoral preparation guide 130 attached to the resected distal portion of the femoral condyle from FIG. 11. The femoral preparation guide 130 includes a distal portion 131 for fitting over and engaging the flat distal surface 122 of the condyle. The distal portion 131 is pinned to the flat distal surface 122 by a series of through-bores and includes a resection slot for a receiving saw, as described below. The posterior portion of the femoral preparation guide 130 includes a lower skid 133 that fits over the top of the posterior region of the condyle. In the illustrated embodiment, the flat inner surface of the distal portion 131 is at a 90° angle relative to the flat inner surface of the skid 133 of the posterior portion of the femoral preparation guide 130. A peghole drill template 132 is located near the junction of the distal and posterior portions. The distal portion of the femoral preparation guide 130 includes a chamfer resection slot 134 and a posterior resection slot 136. Each of these features provides functionality for the preparation work completed on the femur, as the femoral preparation guide 130 is a multi-purpose component that performs the functions of implant sizing, medial-lateral (ML) positioning, bone resection, and peg hole preparation.

[0039] With respect to the implant sizing function, the femoral preparation guide 130 allows the surgeon to confirm size selection using the lateral profile of the distal portion of the femoral preparation guide 130, which mimics the lateral profile of the femoral implant 40 (FIG. 4). The goal is to match and / or correlate the lateral profile of the femoral preparation guide 130 with the circumference of the resected distal condyle. The ML position of the femoral preparation guide 130 is adjusted until the circumference of the distal femoral condyle matches the lateral profile of the femoral preparation guide 130. This process is described in more detail with respect to FIGS. 33A-33E.

[0040] The size of the femoral preparation guide 130 is selected to avoid undercapping or overhang. While slight undercapping is acceptable, slight overhang is undesirable and in most cases unacceptable. In this way, when the femur is between the optional sizes of femoral preparation guide 130, the femoral profile can be evaluated with two femoral preparation guides 130 (one smaller and one larger). The smaller femoral preparation guide 130 should then be selected to avoid overhang.

[0041] Regarding the bone resection and peg preparation functions of the femoral preparation guide 130, after the appropriate size of the femoral preparation guide 130 is selected, it is optimally positioned on the distally resected femoral condyle (from FIG. 11 ) with its posterior skid sitting flush against the posterior condyle and its distal surface resting on the flat distal surface 122 created by the resection using the saw 110 of FIG. 11 . The femoral preparation guide 130 is preferably secured to the bone as follows: Multiple drill bushing holes on the femoral preparation guide 130 accept threaded, headed nails (e.g., size 3.2 mm). Fixation of the nails into the holes of the femoral preparation guide 130 begins with the most anterior hole, followed by the second oblique hole, and the third posterior hole (the use of one of the two holes depends on whether the left or right condyle is being replaced). In one embodiment, two or three pins are used. The pins located in the anterior and oblique pin holes may be sufficient by themselves to secure the femoral preparation guide 130. However, in some cases, when the surgeon feels that additional fixation is necessary (e.g., in softer bone), the innermost pin hole near the handle attachment is optionally used. Once the femoral preparation guide 130 is attached, the preparation sequence using the femoral preparation guide 130 proceeds in a specific order. This process is described with reference to Figures 33A-33E.

[0042] Referring to FIG. 14, femoral preparation guide 130 is used to create femoral peg holes using drill guide 140 that fits around peg hole drill template 132. Peg holes are drilled from the posterior end of femoral preparation guide 130 with a drill 142 that fits within drill guide 140. Guide 140 has an upper boss that provides the desired peg hole depth when a stop element on drill 142 engages the boss. The peg holes rest on a chamfered surface 162, as shown in FIG. 17.

[0043] Referring to FIG. 15 , femoral preparation guide 130 is shown in use to create a posterior resection of the posterior condyle with saw 150. A flat posterior surface 152 is created by saw 150 and extends across the condyle, providing a clearance opening for the posterior chamfer resection process ( FIG. 16 ). As best shown in FIG. 33E (described below), the posterior portion (i.e., the lower skid) of femoral preparation guide 130 is at a 90-degree angle relative to the distal vertical plane of guide 130. Posterior resection slot 136 is angled approximately 5 degrees from this posterior lower skid of femoral preparation guide 130. Thus, flat posterior surface 152 is at an angle of approximately 85 degrees relative to flat distal surface 122. This clearance feature is important because it ensures that the chamfer saw continues to cut through the condyle and does not encroach on the posterior metal skid of femoral preparation guide 130. This feature and function are shown in further detail in FIGS. 33A-33E .

[0044] Next, in FIG. 16 , the femoral preparation guide 130 is used with a saw 160 to create a posterior chamfer 162. The chamfer 162 extends between the flat distal surface 122 and the flat posterior surface 152, as best shown in FIG. 17 . In the illustrated embodiment, the chamfer 162 is at an approximately 45-degree angle relative to the flat distal surface 122. FIG. 17 also shows a chamfer peg hole 172 that will later be used to receive one of the pegs of the femoral implant 40 ( FIG. 4 ). Additionally, the chamfer peg hole 172 is used to receive the femoral trial guide 180 of FIG. 18 . This is to allow the surgeon to perform alignment using the femoral trial guide 180 before completing the preparation.

[0045] FIG. 18 shows the universal handle 80 being used to attach the femoral trial guide 180. Final femoral preparation is completed using the femoral trial guide 180 to assist in developing the distal peg hole preparation, as shown in FIG. 19. The underside of the femoral trial guide 180 has three flat surfaces that engage the flat distal surface 122, the flat posterior surface 152, and the chamfered surface 162. The underside of the femoral trial guide 180 also includes pegs for mating with the chamfered peg holes 172 (FIG. 17).

[0046] 19 , femoral trial guide 180 provides the ability to create distal peg preparations when used in conjunction with drill guide 190. After drill guide 190 is attached to femoral trial guide 180, a drill 192 is used to create distal peg holes in the femoral condyles. Femoral trial guide 180 and drill guide 190 provide alignment and depth control during peg hole preparation with drill 192.

[0047] 20 illustrates the use of a tibial sizer 200 to measure the dimensions of the anterior-posterior and medial-lateral transverse plane 74. The measurements ensure the selection of the correct size tibial surgical template 220 (FIG. 20) and tibial baseplate 20 (FIG. 2). If necessary, an additional sagittal cut in the tibia distal to the existing sagittal plane 74 may be required to allow adequate spacing.

[0048] 21 shows a tibial spacer base 210 with shims 212 used to measure the space from the transverse plane 74 on the tibia 14 to the trial femoral guide 180. Different size shims 212 may be locked to the tibial spacer base 210 via a rotational motion (e.g., a bayonet key connection, etc.) or a dovetail connection that locks mating features. These measurements using the spacer base 210 and shims 212 ensure proper selection of the sizes of the tibial surgical template 220 (FIG. 20), tibial baseplate 20 (FIG. 2), and tibial insert 30 (FIG. 3).

[0049] 22 shows a tibial surgical template 220 on a resected tibial plateau being installed with a tibial impactor 222. The tibial surgical template 220 includes features that allow it to temporarily mate with the tibial impactor 222 during installation. The tibial impactor 222 includes a flexible arm 224 and a handle 226. When force is applied to the handle 226, the force is transmitted along the arm 224, driving a protrusion, such as a keel (not shown), on the bottom of the tibial surgical template 220 into the bone. As discussed below, the tibial surgical template 220 acts as a guide for preparing the tibia and also functions as a trial tibial baseplate prior to final installation of the tibial baseplate 20.

[0050] Figure 23 shows the tibial surgical template 220 on the resected tibial plateau after it has been positioned by the tibial impactor 222 of Figure 22. The tibial surgical template 220 includes openings 230, 232 that allow for the development of peg holes to be used with the pegs 24 on the final tibial baseplate 20 (Figure 2). It also includes side openings 234 that allow for better removal of trial inserts, as shown in Figure 26. The side openings 234 also provide pin fixation, which stabilizes the surgical template 220 on the proximal bone surface prior to peg preparation and trialing.

[0051] 24 shows a drill guide 240 mated with the opening 230 of the tibial surgical template 220. A drill 242 is placed through the drill guide 240 which is used to create a hole in the resected tibial plateau to receive one of the pegs 24 (FIG. 2) on the final tibial baseplate 20. A second peg hole in the bone is created by using the drill 242 and drill guide 240 over the opening 232.

[0052] FIG. 25 illustrates the tibial surgical template 220 being used with the tibial trial insert 250. Because the femoral trial guide 180 substantially mimics the femoral implant 40 (FIG. 4), and the tibial surgical template 220 and trial tibial insert 250 substantially mimic the tibial baseplate 20 (FIG. 2) and tibial insert 30 (FIG. 3), respectively, the components illustrated in FIG. 25 provide the surgeon with a better understanding of how the final implants will operate prior to their final installation. Therefore, any bone or component adjustments can be made prior to final installation. In effect, the tibial surgical template 220 and femoral drill guide 180 are both surgical templates for drilling and trialing implants. The tibial insert 250 includes various openings and cuts 252 to allow for its removal from the tibial surgical template 220 and to provide clearance for pins that secure the tibial surgical template 220 to the bone.

[0053] 26 shows the tibial trial insert 250 being removed from the tibial surgical template 220 using the tool 260. After the tibial trial insert 250 is removed, the tibial surgical template 220 can be removed from the tibia using a common surgical tool, such as a Kocher. FIG. 27 shows the universal handle 80 when being used to remove the femoral trial guide 180 from the femur 12.

[0054] FIG. 28 illustrates the preparation of the femur 12 and tibia 14 after the femoral trial guide 180 and tibial surgical template 220 have been removed. The femoral condyle includes three flat surfaces (flat distal surface 122, flat posterior surface 152, and chamfered surface 162) and two peg holes 172 and 284. The first chamfered peg hole 172 was created using the drill 142 and femoral preparation guide 130 as shown in FIG. 14 . The second peg hole 284 was created by the femoral trial guide 180 with the drill 190 of FIG. 19 . The tibia 14 includes a transverse plane 74 and a sagittal plane 72, as well as two peg holes 282 created by the drill 242 and tibial surgical template 220 of FIG. 24 .

[0055] Figures 29-31 show the placement of the final implant components. Figure 29 shows the tibial impactor 222 being used to install the tibial baseplate 20. In one preferred embodiment, bone cement is applied over the entire prepared bone surface of the tibia 12, including the peg holes 282 (Figure 28). Cement is also applied to the underside of the tibial baseplate 20, including the pegs 24 (Figure 2) that fit into the peg holes 282 and other protrusions (e.g., keels). The cement should adequately cover these surfaces to optimize fixation of the implant to the bone.

[0056] Figure 30 shows a femoral impactor 302 used to install the femoral condylar implant 40 of Figure 4. Cement is applied across both prepared bone surfaces of the femur (flat distal surface 122, flat posterior surface 152, chamfered surface 162) and the two peg holes 172 and 284. Cement is also applied to the underside of the femoral condylar implant 40, including the peg 48 (Figure 4) that fits within the two peg holes 172 and 284. The femoral impactor 302 is used to force the femoral condylar implant 40 into its final position.

[0057] Figure 31 shows an insert impactor 312 used to install the tibial insert 30 into the tibial baseplate 20. As shown in Figure 3, the tibial insert 30 includes structure 34 (see Figure 3) that allows the tibial insert 30 to mate with corresponding features in the tibial baseplate 20 so that the tibial insert 30 is held in place. At this point, the partial knee implant is installed in the patient.

[0058] 32A-32C show three femoral preparation guides 130a, 130b, and 130c associated with corresponding femoral condylar implants 40a, 40b, and 40c. As described above, the femoral preparation guides 130 mimic the contours of the femoral condylar implants 40 to provide proper implant sizing and ML positioning before the appropriate femoral condylar implant 40 is installed. In one preferred embodiment, each femoral preparation guide 130 has a corresponding single femoral condylar implant 40. Thus, as shown in FIGS. 32A-32C, the three femoral preparation guides 130a, 130b, and 130c correspond to only three condylar implants 40a, 40b, and 40c, respectively. The present invention contemplates having more than three matching pairs of femoral preparation guides 130 and condylar implants 40.

[0059] In another preferred embodiment, each femoral guide 130 has a shape and size that represents the circumference of two different femoral condylar implants 40, so that three femoral preparation guides 130a, 130b, 130c are useful with six femoral condylar implants 40. For example, the three femoral guides 130a, 130b, 130c are sizes 1, 3, and 5, but cover sizes 1, 2, 3, 4, 5, and 6 of the femoral condylar implants 40. In other words, each femoral guide 130 is the same size as one condylar implant 40 and is closer in size to the next larger size condylar implant 40. The small femoral guide 130a matches the circumference of size 1 of the condylar implant 40, but covers sizes 1 and 2 of the condylar implants 40. The medium femoral guide 130b matches the circumference of size 3 of the condylar implant 40, but covers sizes 3 and 4 of the condylar implants 40. The large femoral guide 130c matches the circumference of a size 5 condylar implant 40 but covers sizes 5 and 6 condylar implants 40. This allows the surgeon to quickly evaluate between the two size groups. For example, the small guide 130a is equivalent to implant size 1. Therefore, if the small guide 130a is too small, the patient's knee likely requires a size 2 condylar implant 40. Next, by placing the medium guide 130b (size 3) near the placement site, the surgeon can determine if size 3 is too large and can be confident that a size 2 condylar implant 40 is required. Thus, the surgeon uses the small preparation guide 130a (size 1), the femoral drill guide 180, and a size 2 condylar implant 40.

[0060] Figures 33A-33E show details of the attachment of the femoral preparation guide 130 to the femur 12 and its use on the femoral condyles. Figures 33A and 33B show the initial placement of a first pin 332 into the anterior-most through-bore 334 of the distal portion 131 of the femoral preparation guide 130, and the placement of a second pin 336 into the angled through-bore 338 of the distal portion 131. The second pin 336 is guided into the angled through-bore 338 at a different angle than the first pin 332 to help hold the femoral preparation guide 130 in multiple orientations. Figures 33A-33B also show a one-size shim 340 that includes features that fit within a recess or slot 339 in the posterior skid 133 of the femoral preparation guide 130. These are described in detail in Figures 34A-34B. When the shim 340 is driven into the joint space, only the first pin 332 and the second angled pin 336 are required to secure the femoral preparation guide 130. When the bone is soft (i.e., osteopenic), the surgeon may choose to use a third fixation pin in one of the three lower holes in the distal portion 131. Generally, using the third pin in the innermost of the three lower holes is sufficient for attachment.

[0061] The bone preparation and guide stability functions of the femoral preparation guide 130 depend, at least in part, on stabilizing and securing the guide 130 in an anterior-to-posterior sequence, followed by the reverse sequence (posterior-to-anterior) for the actual bone preparation. The specific sequence of steps for securing the guide (anterior-to-posterior) and the subsequent bone preparation steps (posterior-to-anterior) ensures that the femoral preparation guide 130 remains stable. Placing the anterior-most first pin 332 provides the necessary initial stability required before placing the diagonal pin (guide screw) 336. Without the anterior-most first pin 332, the femoral preparation guide 130 would tend to shift when placing the diagonal pin / guide screw 336. After pinning the anterior-most through-bore 334 and the diagonal through-bore 338, a third pin can be used in the innermost of the three lower holes when the bone is soft. In addition to the sequence of steps, the use of a sagittal curve shim 340 facilitates stability during the bone preparation steps. The specific sequence also allows for final adjustments to the implant position, including the final peg holes drilled through the femoral trial guide. Regarding facet and peghole preparation, it is preferable to complete the drilling of the peg holes first to ensure accuracy, since bone resections can compromise accurate fixation of the femoral preparation guide 130 on the bone. As shown in FIG. 33E, with the posterior condyle bone removed, the posterior resection is completed before the posterior chamfer resection, allowing the surgeon to sense when the chamfer resection is complete well before the saw blade contacts the metal posterior skid of the femoral preparation guide 130. Thus, the posterior resection, which creates the posterior flat surface 152, provides clearance for the chamfer saw 160.

[0062] 33C illustrates the use of femoral preparation guide 130 when drilling peg holes using drill guide 140 and drill 142. First pin 332 and second pin 336 are positioned and angled so as not to interfere with drill 142 as it is advanced into femur 12.

[0063] 33D and 33E show that the flat posterior surface 152 from the saw 150 creates a clearance area that allows the saw 160 to create a chamfered surface 162. By developing the flat posterior surface 152 first, the saw 160 needs to cut less bone and does not need to insert as deeply, thereby minimizing the chance of the saw 160 bottoming out on the lower skid 133 of the posterior region of the femoral preparation guide 130.

[0064] FIG. 33E also shows a slot 339 on the posterior skid 133 of the femoral preparation guide 130 that is used to attach a selected shim 340 to the femoral preparation guide 130. In one embodiment of the present invention, the femoral preparation guide 130 includes a slot 339 (or other attachment feature) for receiving a corresponding mating protrusion on a spacer shim 340 that is curved in the sagittal plane. The spacer shim 340 may be locked to the femoral preparation guide 130 via a dovetail mating connection, in which the selected shim 340 has a dovetail-shaped protrusion 342 (shown in FIG. 34B) that slides into a corresponding dovetail slot 339 in the lower skid 133. The lower skid 133 may also include a leaf spring within the slot 339 to provide a snug interference fit with the selected shim 340 as it is slid into place. Alternatively, the spacer shim 340 may be locked to the femoral preparation guide 130 via a rotational motion, for example, using a bayonet key connection.

[0065] Figures 34A and 34B illustrate the femoral preparation guide 130's ability to create the proper spacing for the tibial plateau. The curved spacer shim 340 is available in multiple sizes (e.g., thicknesses and curvatures) to properly fill the joint space. In one preferred embodiment, the flexion space should be approximately 10 mm. However, in some cases, the flexion space may be narrower (e.g., 8-9 mm) due to restricted flexion, or looser (e.g., 11-12 mm) due to excessive wear or ligament instability. The curvature of the spacer shim 340 mimics the typical radius of the posterior femoral condyle. This curvature allows for tibiofemoral movement (i.e., slight flexion), while the rectangular spacer securely fixes the tibiofemoral position at 90-95 degrees (depending on the tibial inclination). In one preferred embodiment, the combined thickness of the lower skid 133 and the selected shim 340 corresponds to the combined thickness of the tibial baseplate 20 and the tibial insert 30. For example, the lower skid 133 of the femoral preparation guide 130 may be approximately 3 mm thick and the spacer shim 340 may be approximately 5 mm thick, resulting in a combined thickness of approximately 8 mm. However, that spacer shim 340 may be labeled as an "8 mm shim," knowing that its thickness in combination with the lower skid 133 results in a total combined thickness of 8 mm.

[0066] The use of a spacer shim 340 on the femoral preparation guide 130 with the desired sagittal curvature, as shown in Figures 34A-34B, provides important benefits to the overall system. First, the curved spacer shim 340 fills the flexion space, resulting in a rectangular, balanced space in the coronal plane. Second, the curved spacer shim 340 utilizes tension applied to the ligaments to further stabilize the overall fixation of the femoral positioning guide, providing a more accurate and repeatable preparation. Third, the curved spacer shim 340 provides a sagittal curvature that accommodates the subtle movements of the knee (tibiofemoral joint) during trial runs involving these components. That is, tibial movement is limited to within 85-95 degrees during flexion (as shown in Figure 34A) during the procedure, preventing the entire femoral preparation guide 130 from loosening from the bone. When assembled to the posterior skid 133 of the femoral preparation guide 130, the shim 340 and skid 133 represent the combined thickness of the tibial insert 30 and tibial baseplate 20 (shown in FIGS. 3 and 31 ). For example, the shim 340 may provide a combined thickness with the lower skid 133 of approximately 8, 9, 10, and 12 mm, matching the combined thicknesses available from kits of tibial insert 30 and tibial baseplate 20. In other words, the shims 340 are available in a variety of thicknesses that allow them to accommodate the thickness of the selected tibial insert 30.

[0067] Alternative Implementations Alternative Implementation 1. A femoral preparation guide for use on a condyle of the femur during a surgical procedure, the condyle for receiving a femoral condyle implant, the femoral preparation guide comprising: a posterior portion for fitting over an upper portion of a posterior region of the condyle; a distal portion for fitting over an upper portion of a distal region of the condyle, the distal portion being angled relative to the posterior portion; and first and second resection slots on the distal portion for receiving a cutting tool that provides two resections of the condyle, the first and second resection slots being angled relative to each other.

[0068] Alternative Implementation 2. The femoral preparation guide of Alternative Implementation 1, wherein the first resection slot is for creating a first posterior cut in the condyle, the second resection slot is for creating a second posterior cut in the condyle, and the second posterior cut provides a chamfer cut that is angled relative to the first posterior cut.

[0069] Alternative Implementation 3. The femoral preparation guide of Alternative Implementation 2, wherein the first posterior cut provides clearance for making the second posterior cut.

[0070] Alternative Implementation 4. The femoral preparation guide of Alternative Implementation 1, further comprising a guide hole for creating a posterior hole that receives a portion of a femoral condyle implant.

[0071] Alternative Implementation 5. A femoral preparation guide according to Alternative Implementation 1, wherein the distal portion has a flat surface for engaging a flat resection surface on the condyle.

[0072] Alternative Implementation 6. A femoral preparation guide as described in Alternative Implementation 1, wherein the distal portion and the posterior portion define an outer periphery, at least a portion of the outer periphery substantially coinciding with a portion of the implant periphery of the femoral condylar implant to provide an indication of the position of the femoral condylar implant when the femoral condylar implant is later placed on the condyle.

[0073] Alternative Implementation 7. A femoral preparation guide as described in Alternative Implementation 1, wherein the posterior portion includes an area for receiving a shim that provides guidance for measuring the joint space up to the tibia.

[0074] Alternative Implementation 8. The femoral preparation guide of alternative implementation 7, wherein the shim is selected from one of a plurality of shims of different sizes.

[0075] Alternative Implementation 9. The femoral preparation guide of Alternative Implementation 1, wherein the distal portion includes multiple guide holes for receiving pins, the guide holes being at different angles relative to one another.

[0076] Alternative Implementation 10. The femoral preparation guide of Alternative Implementation 1, wherein the femoral preparation guide is part of a kit of femoral preparation guides, each femoral preparation guide in the kit corresponding to a particular size femoral condyle implant.

[0077] Alternative Implementation 11. A femoral preparation guide for use on a condyle of the femur during a surgical procedure, the condyle being for receiving a femoral condyle implant, the femoral preparation guide comprising: a posterior portion for fitting over a top of a posterior region of the condyle; and a distal portion for fitting over a top of a distal region of the condyle, the distal portion being angled relative to the posterior portion, the distal and posterior portions defining an outer periphery, at least a portion of the outer periphery substantially matching a portion of the implant periphery of the femoral condyle implant to provide an indication of the position of the femoral condyle implant on the condyle when the femoral condyle implant is later placed on the condyle.

[0078] Alternative Implementation Form 12. A femoral preparation guide as described in Alternative Implementation Form 11, further including first and second resection slots on the distal portion for receiving a cutting tool that provides two resections of the condyle, the first and second resection slots being angled relative to each other.

[0079] Alternative Implementation 13. The femoral preparation guide of alternative implementation 12, wherein the first resection slot is for creating a first posterior cut in the condyle, the second resection slot is for creating a second posterior cut in the condyle, and the second posterior cut provides a chamfer cut that is angled relative to the first posterior cut.

[0080] Alternative Implementation 14. The femoral preparation guide of alternative implementation 13, wherein the first posterior cut provides clearance for making the second posterior cut.

[0081] Alternative Implementation 15. The femoral preparation guide of alternative implementation 11, further comprising a guide hole for creating a posterior hole that receives a portion of a femoral condyle implant.

[0082] Alternative Implementation 16. The femoral preparation guide of alternative implementation 11, wherein the distal portion has a flat surface for engaging a flat resection surface on the condyle.

[0083] Alternative Implementation 17. The femoral preparation guide of alternative implementation 11, wherein the posterior portion includes an area for receiving a shim that provides guidance for measuring the joint space to the tibia.

[0084] Alternative Implementation 18. The femoral preparation guide of alternative implementation 17, wherein the shim is selected from one of a plurality of shims of different sizes.

[0085] Alternative Implementation 19. The femoral preparation guide of alternative implementation 11, wherein the distal portion includes a plurality of guide holes for receiving pins, the guide holes being at different angles relative to one another.

[0086] Alternative Implementation 20. The femoral preparation guide of alternative implementation 11, wherein the femoral preparation guide is part of a kit of femoral preparation guides, each femoral preparation guide in the kit corresponding to a particular size femoral condyle implant.

[0087] Alternative Implementation 21. A femoral preparation guide for use on a condyle of the femur during a surgical procedure, the condyle for receiving a femoral condyle implant, the femoral preparation guide comprising: a posterior portion for fitting over a top of a posterior region of the condyle; a distal portion for fitting over a top of a distal region of the condyle, the distal portion being angled relative to the posterior portion; a chamfered cutting slot on the distal portion for receiving a cutting tool that provides a chamfered surface on the condyle that is angled relative to both the posterior and distal portions; and a guide hole for receiving a drill that creates a peg hole located on the chamfered surface of the condyle.

[0088] Alternative Implementation 22. The femoral preparation guide of alternative implementation 21, further comprising a posterior resection slot on the distal portion for receiving a cutting tool that provides a posterior resection of the condyle, the posterior resection slot being angled relative to the chamfer resection slot.

[0089] Alternative Implementation 23. The femoral preparation guide of alternative implementation 22, wherein the posterior resection slot provides a cut that provides clearance for a cutting tool that provides a chamfered surface.

[0090] Alternative Implementation 24. The femoral preparation guide of alternative implementation 21, wherein the distal portion and the posterior portion define an outer periphery, at least a portion of the outer periphery substantially matching a portion of the implant periphery of the femoral condylar implant to provide an indication of the position of the femoral condylar implant on the condyle when the femoral condylar implant is subsequently placed on the condyle.

[0091] Alternative Implementation 25. The femoral preparation guide of alternative implementation 21, wherein the distal portion has a flat surface for engaging a flat resection surface on the condyle.

[0092] Alternative Implementation 26. A femoral preparation guide according to alternative implementation 21, wherein the posterior portion includes an area for receiving a shim that provides guidance for measuring the joint space to the tibia.

[0093] Alternative Implementation 27. The femoral preparation guide of alternative implementation 26, wherein the shim is selected from one of a plurality of shims of different sizes.

[0094] Alternative Implementation 28. The femoral preparation guide of alternative implementation 21, wherein the distal portion includes a plurality of guide holes for receiving pins, the guide holes being at different angles relative to one another.

[0095] Alternative Implementation 29. The femoral preparation guide of alternative implementation 21, wherein the femoral preparation guide is part of a kit of femoral preparation guides, each femoral preparation guide in the kit corresponding to a particular size femoral condyle implant.

[0096] Alternative implementation 30. A femoral preparation guide for use on a condyle of the femur during a surgical procedure, the condyle for receiving a femoral condyle implant, the femoral preparation guide comprising: a posterior portion for fitting over an upper portion of a posterior region of the condyle, the posterior portion having an attachment element on an underside of the posterior portion; a distal portion for fitting over an upper portion of a distal region of the condyle; and a shim coupled to the attachment element to provide adequate joint space to the tibia, the shim being selected from a plurality of shims, the plurality of shims being different sizes.

[0097] Alternative Implementation 31. The femoral preparation guide of alternative implementation 30, wherein the shim and attachment element include a dovetail mating portion.

[0098] Alternative Implementation 32. The femoral preparation guide of alternative implementation 30, wherein the shim and attachment element are coupled via a rotational motion that engages mating features.

[0099] Alternative Implementation 33. The femoral preparation guide of alternative implementation 32, wherein the mating feature is a bayonet key mating portion.

[0100] Alternative Implementation 34. The femoral preparation guide of alternative implementation 30, wherein the shim includes a curved sagittal surface that follows the radius of the posterior region of the condyle.

[0101] Alternative Implementation 35. A femoral preparation guide for use on a condyle of the femur during a surgical procedure, the condyle being for receiving a femoral condyle implant, the femoral preparation guide comprising: a body for fitting over the top of the condyle, the body having a slot for guiding a resection cut in the condyle, the body having an outer periphery, at least a portion of the outer periphery substantially conforming to a portion of the implant periphery of the femoral condyle implant to provide an indication of at least one of (i) the medial-lateral position of the femoral condyle implant that will subsequently be placed on the condyle, or (ii) the size of the femoral condyle implant that will subsequently be placed on the condyle.

[0102] Alternative Implementation 36. A femoral preparation guide of alternative implementation 35 having features and / or functionality according to any of alternative implementations 1-34.

[0103] Alternative Implementation 37. A femoral preparation component for use on a condyle of a femur during a surgical procedure, the condyle for receiving a femoral condyle implant, the femoral preparation component comprising: a femoral preparation guide having (i) a posterior portion for fitting over an upper portion of a posterior region of the condyle, (ii) a distal portion for fitting over an upper portion of a distal region of the condyle, (iii) at least one resection slot for receiving a cutting tool to provide resection of the condyle, and (iv) a first guide hole for receiving a drill to create a first peg hole located on the condyle; and a femoral trial guide for placement on the condyle after resection developed in the femoral preparation guide, the femoral trial guide including a second guide hole for receiving a drill to create a second peg hole located on the condyle, the first and second peg holes for receiving pegs on the femoral condyle implant.

[0104] Alternative Implementation 38. The femoral preparation component of alternative implementation 37 having features and / or functionality according to any of alternative implementations 1-34.

[0105] Alternative Implementation 39. A femoral preparation component for use on a condyle of the femur during a surgical procedure, the condyle for receiving a femoral condyle implant, the femoral preparation component comprising: a femoral resection guide block that slides over an upper portion of a spacer component positioned in an area below the condyle, the femoral resection guide block including a resection slot for receiving a cutting tool that provides a first resection of the condyle; a femoral preparation guide for attachment to the condyle in the area of ​​the first resection, the femoral preparation guide having two resection slots for receiving cutting tools that provide a second and a third resection of the condyle and including a first guide hole for receiving a drill that creates a first peg hole located on the condyle; and a femoral trial guide for placement on the condyle after the resections developed with the femoral preparation guide, the femoral trial guide including a second guide hole for receiving a drill that creates a second peg hole located on the condyle.

[0106] Alternative Implementation 40. The femoral preparation component of alternative implementation 39 having features and / or functionality according to any of alternative implementations 1-34.

[0107] Alternative implementation 41. A femoral trial guide for use on a condyle of the femur during a surgical procedure, the condyle being for receiving a femoral condyle implant, the femoral trial guide comprising a curved outer surface that mimics the outer surface of the femoral condyle implant to provide an indication of the position and movement of the femoral condyle implant that will be subsequently implanted, and a guide hole for receiving a drill that creates a peg hole located on the condyle.

[0108] Alternative Implementation 42. A method of preparing a condyle for receiving a femoral condylar implant using one or more of the components described in any of Alternative Implementations 1-41.

[0109] Alternative Implementation 43. A kit of components for preparing the femur and tibia for a partial knee replacement, the kit including a tibial surgical template, a tibial trial insert that fits into the tibial surgical template, and one or more of the components described in any of alternative implementations 1-41.

[0110] Alternative implementation 44. A kit of components for preparing a tibia for a partial knee replacement, the kit including one or more of the tibial-related components described with respect to any of Figures 5, 6, 7, 20-26.

[0111] One or more elements, aspects, or steps, or any portion thereof, from any one or more of the above alternative implementations 1-44 may be combined with one or more elements, aspects, or steps, or any portion thereof, from any one or more of the other alternative implementations 1-44, or any combination thereof, to form one or more additional implementations and / or claims of the present disclosure.

[0112] While various examples of the present disclosure have been described above, it should be understood that they have been presented by way of example only, and not limitation. Many modifications to the disclosed examples can be made in accordance with the disclosure herein without departing from the spirit or scope of the disclosure. Thus, the breadth and scope of the present disclosure should not be limited by any of the above examples. Rather, the scope of the disclosure should be defined according to the following claims and their equivalents.

[0113] While the disclosure has been shown and described with respect to one or more implementations, equivalent substitutes and modifications will occur to those skilled in the art upon reading and understanding this specification and the accompanying drawings. Additionally, while a particular feature of the disclosure may be disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of other implementations that may be desirable and advantageous for any given or particular application.

Claims

1. 1. A femoral preparation guide for use on a condyle of a femur during a surgical procedure, the condyle receiving a femoral condyle implant, comprising: a posterior portion that fits over a posterior region of the condyle, the posterior portion including a lower skid and a template bore, the lower skid including a first surface that faces the posterior region of the condyle when the posterior portion fits over the posterior region of the condyle and a second surface that faces away from the posterior region of the condyle when the posterior portion fits over the posterior region of the condyle, the template bore defining a generally cylindrical opening disposed through the first resection slot; a distal portion that fits over a distal region of the condyle, the distal portion being angled relative to the posterior portion and including a first throughbore and a second throughbore, the central axis of the first throughbore being oriented non-parallel to a central axis of the second throughbore, the distal portion having an inner surface that faces the distal region of the condyle when the distal portion fits over the distal region of the condyle, the inner surface and the first surface intersecting along a straight line, the second surface having a slot oriented to be parallel to the straight line, the slot being dovetail-shaped in cross section; the first and second resection slots provided through the distal portion for receiving a cutting tool that provides two resections of the condyle; a shim of a plurality of shims, the shim having a flat surface and a protrusion, the protrusion having a dovetail-shaped cross-section extending from the flat surface on a first side of the shim, the shim having a convexly curved surface on a second side of the shim opposite the first side, the cross-section of the convexly curved surface being aligned parallel to the cross-section of the dovetail-shaped protrusion, the shim being removably attached to the second surface of the lower skid with the protrusion sliding into the dovetail-shaped cross-section slot; the shim is sized such that when the shim is removably attached to the second surface of the lower skid, the shim maintains a spacing between the posterior portion and the resected end of the tibia; the convexly curved surface is shaped such that when the shim is removably attached to the second surface of the lower skid, the convexly curved surface accommodates movement of the tibia relative to the femur in flexion.

2. 2. The femoral preparation guide of claim 1, wherein the first resection slot is for making a first posterior cut in the condyle, the second resection slot is for making a second posterior cut in the condyle, the second posterior cut provides a chamfer cut that is angled relative to the first posterior cut, and the first posterior cut provides clearance for making the second posterior cut.

3. 2. The femoral preparation guide of claim 1, wherein the distal portion and the posterior portion define an outer periphery, at least a portion of the outer periphery substantially coinciding with a portion of an implant periphery of the femoral condyle implant to provide an indication of the position of the femoral condyle implant when the femoral condyle implant is subsequently placed on the condyle.

4. The femoral preparation guide of claim 1 , wherein the first throughbore and the second throughbore are guide holes for receiving pins.

5. 1. A femoral preparation guide for use on a condyle of a femur during a surgical procedure, the condyle receiving a femoral condyle implant, comprising: a posterior portion that fits over a posterior region of the condyle, the posterior portion including a lower skid and a template bore, the lower skid including a first surface that faces the posterior region of the condyle when the posterior portion fits over the posterior region of the condyle and a second surface that faces away from the posterior region of the condyle when the posterior portion fits over the posterior region of the condyle, the template bore defining a generally cylindrical opening disposed through the first resection slot; a distal portion that fits over a distal region of the condyle, the distal portion being angled relative to the posterior portion, the distal portion and the posterior portion defining an outer periphery, at least a portion of which substantially coincides with a portion of an implant periphery of the femoral condyle implant and provides an indication of the position of the femoral condyle implant on the condyle when the femoral condyle implant is subsequently placed on the condyle, the distal portion including a first through bore and a second through bore, the central axis of the first through bore being oriented non-parallel to the central axis of the second through bore, the distal portion having an inner surface that faces the distal region of the condyle when the distal portion fits over the distal region of the condyle, the inner surface and the first surface intersecting along a straight line, the second surface having a slot oriented to be parallel to the straight line, the slot having a dovetail shape in cross section; the first and second resection slots provided through the distal portion for receiving a cutting tool that provides two resections of the condyle; a shim of a plurality of shims, the shim having a flat surface and a protrusion, the protrusion having a dovetail-shaped cross-section extending from the flat surface on a first side of the shim, the shim having a convexly curved surface on a second side of the shim opposite the first side, the cross-section of the convexly curved surface being aligned parallel to the cross-section of the dovetail-shaped protrusion, the shim being removably attached to the second surface of the lower skid with the protrusion sliding into the dovetail-shaped cross-section slot; the shim is sized such that when the shim is removably attached to the second surface of the lower skid, the shim maintains a spacing between the posterior portion and the resected end of the tibia; the convexly curved surface is shaped such that when the shim is removably attached to the second surface of the lower skid, the convexly curved surface accommodates movement of the tibia relative to the femur in flexion.

6. 6. The femoral preparation guide of claim 5, wherein the second posterior cut provides a chamfer cut that is angled relative to the first posterior cut, the first posterior cut providing clearance for making the second posterior cut.

7. The femoral preparation guide of claim 5 , further comprising a guide hole for creating a posterior hole that receives a portion of the femoral condyle implant.

8. The femoral preparation guide of claim 5 , wherein each shim of the plurality of shims has a different size measured between the flat surface and the convexly curved surface.

9. The femoral preparation guide of claim 5 , wherein the first throughbore and the second throughbore are guide holes for receiving pins.

10. 1. A femoral preparation guide for use on a condyle of a femur during a surgical procedure, the condyle receiving a femoral condyle implant, comprising: a posterior portion that fits over a posterior region of the condyle, the posterior portion including a lower skid and a template bore, the lower skid including a first surface that faces the posterior region of the condyle when the posterior portion fits over the posterior region of the condyle and a second surface that faces away from the posterior region of the condyle when the posterior portion fits over the posterior region of the condyle, the template bore defining a generally cylindrical opening disposed through the first resection slot; a distal portion that fits over a distal region of the condyle, the distal portion being angled relative to the posterior portion and including a first throughbore and a second throughbore, the central axis of the first throughbore being oriented non-parallel to a central axis of the second throughbore, the distal portion having an inner surface that faces the distal region of the condyle when the distal portion fits over the distal region of the condyle, the inner surface and the first surface intersecting along a straight line, the second surface having a slot oriented to be parallel to the straight line, the slot being dovetail-shaped in cross section; a chamfer cutting slot on the distal portion for receiving a first cutting tool to provide a chamfer surface on the condyle; the posterior resection slot on the distal portion for receiving a second cutting tool; a shim of a plurality of shims, the shim having a flat surface and a protrusion, the protrusion having a dovetail-shaped cross-section extending from the flat surface on a first side of the shim, the shim having a convexly curved surface on a second side of the shim opposite the first side, the cross-section of the convexly curved surface being aligned parallel to the cross-section of the dovetail-shaped protrusion, the shim being removably attached to the second surface of the lower skid with the protrusion sliding into the dovetail-shaped cross-section slot; the shim is sized such that when the shim is removably attached to the second surface of the lower skid, the shim maintains a spacing between the posterior portion and the resected end of the tibia; the convexly curved surface is shaped such that when the shim is removably attached to the second surface of the lower skid, the convexly curved surface accommodates movement of the tibia relative to the femur in flexion.

11. 11. The femoral preparation guide of claim 10, wherein the distal portion and the posterior portion define a periphery, at least a portion of the periphery substantially coinciding with a portion of an implant periphery of the femoral condyle implant to provide an indication of the position of the femoral condyle implant when the femoral condyle implant is subsequently placed on the condyle.

12. The femoral preparation guide of claim 10 , wherein the inner surface has a flat surface for engaging a flat resection surface on the condyle.

13. The femoral preparation guide of claim 10 , wherein the first throughbore and the second throughbore are guide holes for receiving pins.

14. The femoral preparation guide of claim 1 , wherein each shim of the plurality of shims has a different size measured between the flat surface and the convexly curved surface.

15. The femoral preparation guide of claim 1 , wherein the convexly curved surface of the shim is configured to follow the radius of a posterior region of the condyle.

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