BR102014018781A2 - systems and methods for the provision of a femoral component - Google Patents

Abstract

Abstract systems and methods for providing deeper knee flexion capabilities. in some instances, such systems and methods include a femoral knee replacement component that includes a joint surface, a first interior surface, and a second interior surface, wherein the first and second interior surfaces run parallel to each other. In some cases, the articular surface includes an anterior condylar extension that is configured to replace an anterior articular cartilage of a femur such that the anterior extension is configured to terminate adjacent to a proximal limit of the anterior articular cartilage of the femur. other implementations are also discussed.

Description

Report of the Invention Patent for "SYSTEMS AND METHODS FOR PROVISION OF A FE-MORAL COMPONENT".

BACKGROUND OF THE INVENTION 1. Related Applications This is a continuation in part of United States Patent Application Serial No. 13 / 758,855, filed February 4, 2013, entitled SYSTEMS AND METHODS FOR PROVI-DING STEM ΟΝ A TIBIAL COMPONENT, which is a continuation application for United States Patent Application Serial No. 12 / 797,372 (now United States Patent No. 8,366,783), filed June 9, 2010, entitled SYSTEMS AND METHODS FOR PROVIDING DEEPER KNEE FLEXION CAPABILITIES FOR KNEE PROSTHESIS PATIENTS, which is a continuation in part of United States Patent Application Serial No. 12 / 482,280 (now United States Patent No. 8,382,846), filed on 10 May June 2009, entitled SYSTEMS AND METHODS FOR PROVI-DING DEEPER KNEE FLEXION CAPABILITIES FOR KNEE PROSTHESIS PATIENTS, which is a continuation in part of United States Patent Application Serial No. 12 / 198,001 (now United States Patent No. 8,273,133), filed August 25, 2008, entitled SYSTEMS AND METHODS FOR PROVIDING DEEPER KNEE FLEXION CAPABILITIES FOR KNEE PROSTHESIS PATIENTS, which claims priority for United States Provisional Patent Application Serial No. 60 / 968,246, filed August 27, 2007, entitled SYSTEMS AND METHODS FOR PROVIDING DEEPER KNEE FLEXION CAPABILITIES FOR KNEE PROSTHESIS PATIENTS, and for United States Provisional Patent Application No. 60 / 972,191, filed September 13 of 2007, entitled SYSTEMS AND METHODS FOR PROVIDING DEEPER KNEE FLEXION CAPABILITIES FOR KNEE PROS-THESIS PATIENTS, each of which is incorporated herein by reference in its entirety. 2. Field of the Invention The present invention relates to knee prostheses. In particular, the present invention relates to systems and methods for providing deeper knee flexion, or full functional flexion capabilities, physiological load bearing and improved patellar follow-up for knee prosthesis patients. Specifically, these enhancements include one or more of the following: (i) the addition of more articular surface to the anteroposterior posterior condyles of a femoral component, including methods for obtaining this result, (ii) changes in the internal geometry of the femoral component and femoral bone sections associated with implantation methods, (iii) asymmetrical tibial components that have a single joint surface that allows deeper knee flexion than previously available, (iv) asymmetrical femoral condyles resulting in more physiological loading and (v) resection essentially of the entire articular femoral anterior cartilage and underlying bone, but no additional bone and replacement thereof with a femoral component that does not have an anterior flange, as seen in contemporary prostheses. 3. Background and Related Art Orthopedic surgeons are experiencing a proliferation of knee replacement surgeries. Demand seems to be driven by the fact that new procedures return as much quality of life as joint replacement.

Moreover, the increased need for knee replacements implies the need for durable and long-lasting artificial knee devices that provide and allow full functional flexion. That is, there is a great need for research to provide new medical advances in the overall function and performance of knee prostheses, and to improve the corresponding surgical materials and technologies related to these devices.

[005] Improvements in knee prostheses correspondingly increase with demand. Thus, currently available knee prostheses mimic the characteristics of the normal knee more than those previously used. Unfortunately, knee prostheses today still have many drawbacks.

[006] Among the drawbacks is the inability of a knee prosthesis patient to achieve deep knee flexion, also known as full functional flexion. Although some currently available knee prostheses allow a knee flexion (ie, a bend) of more than 140 degrees from a full limb extension (zero degree being when the patient's knee is fully extended and straight); Some of these prostheses do not allow patients to flex from a full extension to 160 degrees and beyond. A full or deep functional knee flexion is when the limb is bent to its maximum extent, which can be with the femur and tibia at an angle of 140 degrees or more, although the actual angle varies from person to person. and with the physical constitution. A full extension is when the leg / limb is straight and the person is in a standing position.

[007] For illustration of the average range of degrees obtained by patients having standard knee prostheses, the following is provided. When a patient's knee or limb is fully extended, the femur and tibia are in the same plane at zero degrees, or even 5 to 10 degrees of hyperextension in some individuals. However, once the knee bends and the distal tibia moves toward the buttocks, the angle increases from zero to 90 degrees for a person sitting in a chair. Moreover, when the tibia is closer to the femur and the heel is almost touching, when not touching the buttock, the angle is around 160 degrees or more. Most patients with conventional knee prostheses are unable to consistently reach the last position or any position that places the knee joint at angles above 130 degrees (for example, 160 degrees and beyond).

For many people, such a limb and body position is not often attained or desired most of the time. However, almost everyone, at some point in life, whether it occurs when a person sits or gets up from the floor while playing with children, or merely incidentally to those with active lifestyles, is in a position requiring knee flexion greater than 130 degrees. Unfortunately, those with currently available knee prostheses are unable to engage in any activity requiring greater knee flexion and are thus limited to watching from outside.

In many populations and cultures, such a limb / knee and body position is desired and required most of the time. For example, in Asian and Indian cultures, a full functional flexion in a squatting position is common and performed for relatively long periods of time.

Therefore, there is a need for knee prostheses for these patients, and especially for those cultures, where crouching, sitting with fully flexed knees, and / or kneeling when praying or eating is common for greater knee flexion than currently possible among those with currently available knee prostheses.

Thus, although there are currently techniques that relate to knee prostheses, there are still challenges. Therefore, it would be an improvement in technique to increase or even replace current techniques with other techniques.

SUMMARY OF THE INVENTION

The present invention relates to knee prostheses. In particular, the present invention relates to systems and methods for providing deeper knee flexion capabilities for knee prosthesis patients, and more particularly in performing one or more of the following: (i) providing an area greater articular surface to the femoral component of a knee prosthesis, with a modification of or affixing to the femoral component of a knee prosthesis, which, when integrated with the patient's femur and an appropriate tibial component, results in functional flexion full; (ii) the provision of modifications in the internal geometry of the femoral component and the opposite femoral bone with implantation methods; (iii) the provision of asymmetrical lower surfaces in the tibial component of the knee prosthesis and uniquely positioned joint surfaces to facilitate full functional flexion; (iv) asymmetrical fetal condylar surfaces with a lateralized patellar (trochlear) cavity to more closely replicate a physiological loading of the knee and to provide better patella tracking; and (v) resection essentially of the entire anterior femoral articular cartilage and underlying bone, but no additional bone and replacement thereof by a femoral component that does not have an anterior flange, as seen in contemporary prostheses.

In a normal knee, there is an active flexion cessation at approximately 120 ° in the first place, because the hamstring muscles lose their mechanical advantage, and secondly, because the mediate femoral condyle rolls posteriorly, which does not occupies up to 120 °. By 120 ° of flexion, the femoral mediate condyle begins to roll back relative to the posterior tip of the tibial mediais meniscus. At 140 ° of flexion, the femur moves upward over the posterior tip of the meniscus mediai. Therefore, the flexural strength is felt at this point and beyond. By full flexion, the femoral mediate condyle moved back approximately 8 mm from its 120 ° position to a 10 mm position from the posterior tibial cortex. Laterally, the femur moves back an additional 5 mm in hyperflexion, so that there is little or no tibiofemoral rotation between 120 ° and 160 °, the posterior tip of the lateral meniscus comes to the posterior surface of the distal tibia of the femoral condyle. As such, the posterior tip is not compressed and the two bones are in direct contact.

The final limit for hyperflexion arises because the posterior tip of the meniscus mediates a flexion at 140 ° and absolutely limits it at 160 °. The posterior tip also prevents the medial femoral condyle from moving backward beyond a point 10 mm from the posterior tibial cortex. Thus, the posterior tip of the meniscus mediais is a key structure for achieving deep flexion.

[0015] The implementation of the present invention occurs in association with improved knee prostheses that allow patients with a knee prosthesis to achieve greater deep knee flexion than previously obtainable using the presently designed knee prostheses. In at least some embodiments of the present invention, greater deep knee flexion is provided to the knee prosthesis by resection of portions of the femur to allow additional space for the posterior tip of the media meniscus and tibia. In other implementations in which a portion of the tibia is replaced by a prosthesis, however, the posterior tip is left intact. Additionally, at least some embodiments of the present invention further provide for positioning and / or installation of a joint surface with dry portions of the femur for providing an interface between the posterior tip of the media meniscus and the dry surface of the femur.

In at least some embodiments of the present invention, greater deep knee flexion is provided for the knee prosthesis by providing an articular surface on the proximal anterior surface (or portion) of the posterior femoral condyles. At least some embodiments of the present invention involve an additional or enlarged articular surface in the proximal anterior portion of one or both of the medial or lateral posterior condyles of the femoral component of the prosthesis. The additional femoral component modalities an increased articular surface area to the proximal end of the posterior condyles of the femoral component in an anterior direction, so that when the patient flexes his knee during a deep knee flexion, a contact between the femoral component and the tibial component is maintained, and greater deep knee flexion can be obtained.

In at least some embodiments of the present invention, greater deep knee flexion may be provided or enhanced by modification of the tibial joint, wherein the center of the tibial articular surface of conformation of the tibial component of the prosthesis is moved posteriorly relative to it. what is currently available. Additionally, in some of these embodiments, the overall shape of the lateral tibial joint surface is modified.

In at least some embodiments of the present invention, a greater deep knee flexion may be achieved by providing an asymmetrical femoral component of the prosthesis. The asymmetrical femoral component allows a transfer of more than half of the force transmitted through the joint to be transmitted to the mediate side, as occurs in the normal knee. In some implementations, other modifications to the tibial and femoral components of a knee prosthesis may be made, including having asymmetrical femoral condyles, having a closing radius on the femoral component, and removing certain areas of the tibial and femoral components; where all of the above results in deep knee flexion capabilities for knee prosthesis patients than previously obtained.

At least some implementations of the present invention include a femoral component (and associated methods for making and using such a component) that includes a femoral articular surface extending in an anterior direction from a proximal end of a posterior condyle of a femoral knee replacement component, the femoral component still having a full anterior articular extension, which replaces the anterior articular cartilage of a femur. In some cases, the femoral component includes a first inner surface and a second inner surface that run substantially parallel to each other. In other cases, the first inner surface and the second inner surface of the femoral component differ from each other less than an angle of 45 °. In some cases, the first inner surface and the second inner surface differ from each other by an angle of from about 3 ° to about 10 °.

Although the methods, modifications and components of the present invention have proven to be particularly useful in the area of knee prostheses, those skilled in the art will appreciate that the methods, modifications and components may be used in a variety of ways. different orthopedic and medical applications.

These and other features and advantages of the present invention will be established or become more apparent from the following description and the appended claims. Features and advantages may be realized and obtained by means of the instruments and combinations particularly set forth in the appended claims. Moreover, the features and advantages of the invention may be learned by practicing the invention or will be apparent from the description as set forth hereinbelow.

BRIEF DESCRIPTION OF DRAWINGS

In order that the manner in which the above and other features and advantages of the present invention are obtained will be understood, a more particular description of the invention will be presented with reference to specific embodiments thereof, which are illustrated in the accompanying drawings. attached. An understanding that the drawings describe only typical embodiments of the present invention and therefore should not be construed as limiting the scope of the invention, the present invention will be described and explained with further specificity and detail through the use of the associated drawings, in which: [ 0023] Figures 1A and 1B describe flexion bands of a knee joint;

Figures 2A to 2C and 3A to 3C depict various views of a generic knee prosthesis;

Figures 4A to 4D depict representative perspective views of embodiments of a femoral component of a knee prosthesis according to embodiments of the present invention;

Figures 5A to 5D depict representative perspective views of embodiments of a femoral component of a knee prosthesis according to embodiments of the present invention;

Figures 6A-6B depict side views of a prior art tibial component representative of a knee prosthesis;

Figures 6C to 6D depict side views of a representative embodiment of a tibial component according to embodiments of the present invention;

Figures 6E to 6F depict an alternative embodiment of a representative tibial member modified to include a high ridge pivot feature;

Figures 6G to 6H depict an alternative embodiment of a representative tibial member modified to include a spherical pivot feature;

Fig. 6I illustrates an alternative embodiment of a representative tibial member modified to include the high ridge pivot feature;

Figures 6J and 6K depict side views of a representative embodiment of a tibial component according to embodiments of the present invention;

Figures 7A and 7B depict alternative embodiments of the femoral and tibial components in accordance with embodiments of the present invention;

Figure 8A illustrates a conventional femoral component, while Figure 8B illustrates an embodiment of a femoral component in accordance with the present invention;

Fig. 9 illustrates a modular display for use with one-femoral component embodiments in accordance with the embodiments of the present invention;

Figures 10A to 10H illustrate representative steps for affixing one embodiment of a femoral component to a femur, the resected portions of the femur shown hatched;

Figures 11A to 11K illustrate representative steps for affixing an alternative embodiment of a femoral component to a femur;

Figures 12A to 12C and Figure 13 illustrate comparisons between a conventional femoral component and some embodiments of a femoral component in accordance with embodiments of the present invention;

Figure 14 illustrates an alternative embodiment of a femoral component according to embodiments of the present invention;

Figures 15A-15E illustrate comparisons between modalities of a femoral component;

Figures 16A-16D illustrate a manner in which a pivoting surface of the femoral components shown in Figures 15A-15D may be extended;

Fig. 16E illustrates a shortened embodiment in which a hinge surface of the femoral component may be extended;

Figures 16F to 16P illustrate a flexion of a non-limiting embodiment of a femoral component having a decreasing radius, wherein the decreasing radius provides lassitude for a portion of the flexure strip in accordance with a representative embodiment of the present invention;

Fig. 16Q illustrates a unicompartmental femoral component including an extended articulating surface in accordance with a representative embodiment of the present invention;

Fig. 16R illustrates a unicompartmental femoral component including a decreasing radius and a recess in accordance with a representative embodiment of the present invention;

Figure 16S illustrates a truncated femoral component including a recess in accordance with a representative embodiment of the present invention;

Figure 16T shows a cross-sectional view of a femoral component coupled to a modular patellofemoral component in accordance with a representative embodiment of the present invention;

Figure 16U shows a cross-sectional view of a slidingly coupled femoral component to a modular patellofemoral component according to a representative embodiment of the present invention;

Fig. 16V illustrates a detailed cross-sectional view of a femoral component having a tapered aperture slidable or adjustable to a pin of a modular patellofemoral component according to a representative embodiment of the present invention;

Figure 16W illustrates a cross-sectional view of a femoral component having a convex surface confined to a concave surface of a modular patellofemoral component in accordance with a representative embodiment of the present invention;

Figures 16X to 16Z illustrate flexion of a non-limiting embodiment of a femoral component having a femoral full flexion joint according to a representative embodiment of the present invention;

Figure 17 illustrates the drawing of a radiograph of a normal knee flexed to approximately 160 degrees and further illustrates the position of the patella;

Figures 18A-18C illustrate alternative embodiments of a femoral component according to a representative embodiment of the present invention;

Fig. 19A illustrates a tibial component that has no articular surface posterior to the main articular surface;

Fig. 19B illustrates the tibial full flexion joint being posterior to the main weight support joint;

Figures 20A-20I illustrate a representative interaction of the femoral full flexion joint and the tibial full flexion joint;

Figure 21 illustrates a representative interaction of the posterior articulated surface of the tibial mediate plateau and popliteal surface during a deep knee flexion;

Fig. 22 illustrates a representative implementation of a resection block and femur following resection of the popliteal surface;

Fig. 22A illustrates a representative implementation of a resection block and femur prior to resection of the popliteal surface;

Figure 23 illustrates a representative interaction of the posterior articular surface of the tibial mediate plateau and an extended portion of the femoral component of the knee prosthesis during a knee flexion;

Fig. 23A illustrates a representative interaction of the posterior full flexion joint surface of the tibial plateau mediating a tibial component and an extended portion of the femoral component of the knee prosthesis during a deep flexion;

Fig. 24 illustrates a cross-sectional view of a tibial component and a stem inserted into a tibia, according to a representative embodiment of the present invention;

Figures 25 to 27 illustrate various rod embodiments according to representative embodiments of the present invention;

28A illustrates an adjustable shank according to a representative embodiment of the present invention;

Fig. 28B illustrates a tibial component comprising a modular stem according to a representative embodiment of the present invention; and Figures 29A to 29C each illustrate a different representative embodiment of an implanted femoral component having two opposing internal surfaces that run substantially parallel to each other.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to knee prostheses. In particular, the present invention relates to systems and methods for providing deeper knee flexion capabilities for knee prosthesis patients, and more particularly to: (i) providing an extended articular surface on the proximal anterior surface (or portion) of the posterior condyles of the femur; (ii) make modifications to the internal geometry of the femoral component and the femoral bone sections associated with implantation methods; (iii) make modifications to the tibial and femoral components of a knee prosthesis, including asymmetrical tibial joint surfaces and remove certain areas of the tibial and femoral components; (iv) have asymmetrical femoral condyles, including the option of having a closing radius on the femoral component, where all of the above results in deeper knee flexion capabilities for knee prosthesis patients than previously obtainable; and (v) resection essentially of the entire anterior femoral articular cartilage and underlying bone, but no additional bone and replacement thereof by a femoral component that does not have an anterior flange, as seen in contemporary prostheses.

It is emphasized that the present invention, as illustrated in the figures and description herein, may be embodied in other forms. Thus, neither the drawings nor the following more detailed description of the various embodiments of the system and method of the present invention limit the scope of the invention. The drawings and detailed description are merely representative of exemplary embodiments of the invention; The substantive scope of the present invention is limited by the appended claims recited for the description of the many embodiments. The various embodiments of the invention will be better understood by reference to the drawings, wherein like elements are designated by the same alphanumeric characters by all of them.

Referring now to the accompanying drawings, Figures 1A to 3C are provided for general reference to assist in understanding the features of the embodiments of the present invention. Figures 1A and 1B depict a range of possible angles between the tibia and femur in a person who is extending and flexing (bending) his knee. Specifically, Figure 1A depicts a range of possible angles as the person extends and bends his knee, realizing that some knees can bend to 160 degrees, 165 degrees, or beyond. Figure 1B depicts these various angles in an alternate position. These figures should be borne in mind during the discussion illustrating how, with the embodiments of the present invention, knee flexion of greater than 135 degrees is possible for knee prosthesis patients, which is generally not possible with knee prostheses today. available.

Figures 2A to 2C depict various perspective views of a generic knee prosthesis 10. Specifically, Figure 2A depicts a sagittal view of a left knee joint having a knee joint prosthesis 10 with the tibia and the knee joint. normal knee femur transparent. Figure 2B depicts an enlarged view of a femoral component 12 of the knee prosthesis 10, while Figure 2C provides a top perspective view of a tibial component 14 of the knee prosthesis. Figure 2B depicts certain components of the femoral component 12, such as the media receiving area 16, and may be modified in embodiments of the present invention to fully connect to a display (not shown, but described hereinafter) as well as an area. lateral receiving section 18. The internal geometry of the femoral component 12 is provided to allow a one-piece femoral component 12 to be rolled into place in the dried femur 32 as shown in Figure 4D. Thus, the internal geometry of the femoral component 12 includes various surfaces, including areas 16 and 18, for accommodating the patellar joint and anterior extensions of the proximal portions of the posterior condyles. The dried portions of the condyles provide flat surfaces which are loaded to compression in full knee flexion. Additionally, the resected surfaces are provided such that the articular surface of the femoral component is essentially in the same position as the surface being resected. As such, the normal relationship between the femur and the tibia is preserved with full flexion. Additionally, when the knee is fully flexed, the interface between the femoral component and the underlying femur is charged primarily to compression rather than shear forces. Compression forces provide a more stable interface between the femoral component and the femur, thereby decreasing the chances of loosening. Therefore, in some embodiments, the interfaces between the femoral component and the tibial component are configured to improve a compressive force between the femoral component and the underlying femur during full knee joint flexion.

Also visible in FIG. 2B is a medial femoral condylar surface 20 and a lateral femoral condylar surface 22. Figure 2C depicts the tibial component 14 and its elements: a lateral tibial condylar surface 24, a tibial mediaillary condylar surface 26 and a intercondylar surface 28. When the knee prosthesis 10 is functioning, there is an interface between the femoral condyle surface 20 of the femoral component 12 and the tibial condyle surface 26 of the tibial component 14, and between the lateral femoral condylar surface 22 of the femoral component 12 and the lateral tibial condylar surface 24 of the tibial component 14.

Figures 3A to 3C depict additional perspective views of the generic knee prosthesis 10 with its different components. Specifically, Figure 3A depicts a front view of the knee prosthesis 10 with the femoral component 12 articulating with the tibial component 14 as described above. Figure 3B is a side view of the femoral component 12, and Figure 3C is a side view of the tibial component 14, and specifically the medial side of the tibial component showing the tibial condylar surface 26. The mediai femoral condylar surface 20 has a sliding interface with the tibial condylar surface 26 so that, as a person flexes or extends his knee, the arc of the femoral condylar surface 20 runs along the tibial condylar surface 26.

In some embodiments of the present invention, a larger deep knee flexion is provided for the knee prosthesis 10 by providing an articular surface on the proximal anterior surface (or portion) of the posterior condyles of the femur. At least some embodiments of the present invention involve an additional or enlarged articular surface in the proximal anterior portion of either or both of the medial or lateral posterior condyles of the femoral component 12. Modifications of the femoral component 12 add an enlarged articular surface area to the extremity. the posterior condyles of the femoral component 12 in an anterior direction, so that when the patient flexes his knee during a deep knee flexion, contact between the femoral component 12 and the tibial component 14 is maintained, and a knee flexion deeper depth can be obtained.

Four different examples of how this can be achieved are shown with reference to the figures. Any method of increasing a joint surface area to the proximal end of the posterior condyles of the femoral component 12 in an anterior direction is encompassed by the embodiments of the present invention.

Figures 8A and 8B illustrate a femoral component 12 and a method of increasing a joint surface area to the proximal end of the posterior condyles of the femoral component 12. Figure 8A illustrates a side view of a conventional femoral component 12. In the first embodiment of the inventive prosthesis, the shaded area of the femoral component 12 of FIG. 8A (i.e. the posterior condyle) is thickened anteriorly until the resulting surface opposite the bone is approaching the same plane as the posterior surface of the shaft. Distal femur. This thickening can be seen with reference to figure 8B. In particular, Figure 8B shows that in some embodiments, the posterior condyle is thickened from its most posterior edge (as illustrated by line 300) toward a plane 302 of a distal posterior surface portion of the distal femoral axis. . This results in a larger articular surface area of the posterior condyles of the femoral component 12. This requires resection of more bone, but otherwise is an easy modification to current prostheses and requires little to no modification of current surgical technique.

A second type of embodiment extending the articular surface area is illustrated in Figures 4A to 5C. The methods of using this type of embodiment are illustrated with reference to figures 9 to 10H. This type of modality utilizes an extension attachment to the femoral component 12 of a knee prosthesis modality 10, which, when integrated with the femoral component 12 and a patient's femur, results in a larger surface area of the femoral component 12.

As shown in Figures 4A to 5D, this type of embodiment has a modular display 30 which provides a modular flexion display surface to extend the articular surface area of the anterior portion of the proximal portion of the posterior condyles. Modular affix 30 may be affixed to the inner or non-articular surface of a relatively conventional full knee femoral component 12. Modular affix 30 has a portion that may be partially received, in one embodiment, in a recessed receiving area on the flat anterior surface of one or both posterior condyles of the femoral component 12 and thus may be used in the posterior mediate condyle, lateral posterior condyle or both. Alternatively, it may be implanted in a cavity within either or both of the resected posterior condyles of the femur itself.

Modular display 30 provides an increased joint contact area as an anterior continuation of the femoral mediate condylar surface 20 and / or lateral femoral condylar surface 22 of the femoral component 12. In some embodiments, the modular display 30 may initially be placed. over the femoral component 12 and then affixed to the distal end of the patient's femur. In other embodiments, the modular fixation 30 may first be connected to the posterior condyles of the distal end of the femur and then integrally connected to the femoral component 12. The modular fixation 30 may be used on the medial side, lateral side or both sides. .

Figures 4A to 4D depict perspective views of modalities of the femoral component 12 and modular display 30. As described, modular display 30 attaches to a patient's femoral component 12 and femur to increase the surface area of the component. femoral 12 and finally allow deep knee flexion beyond 140 degrees in a patient with a knee prosthesis. Figure 4A depicts a simplified side view of one embodiment of the femoral component 12 having the modular affix 30 affixed to the posterior condyle of the femoral component. Figure 4D depicts a side view of the attachment fully affixed to a patient's femur and to the femoral component of the knee prosthesis. Modular display 30 may be modular, as shown in Figures 4B to 4D, and may fit in a recess in either or both of the middle receiving area 16 and the lateral receiving area 18 (i.e., the front inner surface of the posterior condyles of the femoral component 12, as shown in Figure 2B), and / or either or both of the femoral mediate and lateral posterior condyles, or both the femoral component 12 and the femur. In another embodiment, the modular display 30 may be a permanent part of the femoral component as discussed below.

Figure 4B depicts a side view of a modular display embodiment 30, and Figure 4C depicts a top view of the described embodiment of modular display 30. The specific dimensions of the described embodiment of modular display 30 are not given, and one of ordinary skill in the art will recognize that dimensions can be changed from patient to patient and will also recognize that the various portions of the modular display 30 may all be formed in some embodiments to be as large as the femoral component condyle 12.

In some embodiments, the modular display 30 includes a first portion approximately perpendicular to a second portion. The first portion of the modular affix 30 surrounds a flanged joint area 36 ("flanged area 36") at one end of the modular affix 30, and an elongate rod 38 extending therefrom which extends approximately perpendicular from the area. flanged area distal to the flanged area 36. Therefore, the elongated rod 38 is affixed to the non-articular side of the flanged area 36. Although the elongated rod is shown in Figure 4C as having a substantially shorter mediaillary width than the In the medial lateral width of the flanged area 36, the elongated stem 38 of other embodiments may be of any medial lateral width to the medial lateral width of the posterior condyles of the femoral component 12 itself.

The elongate shank 38 has an upper side 40 and a lower side 42. The nodules 44 may be positioned on either or both the upper side 40 and the lower side 42 to allow integral connection with the femur 32 in the neck. upper side 40 and femoral component 12 on lower side 42. Some form of nodule receiving cavity or recess (not shown) may be made in femur 32 and or femoral component 12 for receiving these nodules 44 and for fixation the integral connection between the femur 32, the fixation 30 and the femoral component 12; with the modular fixation 30 being arranged between the femur 32 and the femoral component 12.

In embodiments having no node 44 in the elongate stem 38, the display 30 may fit into a recess made in either or both of the medial receiving area 16 and the lateral receiving area 18 of the femoral component 12. The nail The length 38 of the modular display 30 would fit into these recesses and be integrally connected to it. Modular affix 30 may connect simultaneously with the femur 32 on the upper side 40 (usually) of the elongate stem 38. In embodiments without nodules on the elongate stem, the modular portion stem may still fit into a cavity prepared in the resected posterior condyles. of the femur.

Modular affixing 30 increases the overall surface area of the femoral component 12 and prolongs the interface and contact that exists between the femoral component 12 and the tibial component 14. This allows for greater knee flexion in knee prosthesis patients, because the femoral component 12 remains interfaced with the entire tibial component 14 throughout the full flexion range, resulting in painless knee flexion.

Without this enlarged surface area, the medial and lateral proximal edges of the posterior femoral condyles of a prosthesis could push the proximal surfaces of the tibial component 14 and could produce wear of the tibial component 14. In addition, the tibial component 14 may contact the femur bone 32 that is anterior and / or proximal to the proximal edges of the posterior condyle of the prosthesis causes pain and limits flexion of the patient with a knee prosthesis and may cause tibial component wear. Still, without this added surface area, with flexion beyond 140 degrees, the tibial component 14 can exert a force in the distal direction of the femoral component 12, resulting in a loosening of the femoral component 12. Therefore, the modular fixation 30 extends Prosthetic knee life decreases patient pain and ultimately allows a patient with a knee prosthesis to achieve deep or fully functional knee flexion.

Figures 5A to 5D describe various perspective views of the modular fixation 30 as it is affixed to the femoral component 12 and the femur 32. Figure 5A is illustrative of the modular fixture 30 as it is affixed to the femur 32 prior to Femoral Component Attachment 12. Figures 5B to 4D are illustrative of the modular affix 30 as it is recessed in the femoral component 12 prior to affixing to the femur 32 and specifically, the modular affix 30 is integrally connected to either or both the femoral mediation receiving area 16 and the lateral femoral receiving areas 18.

Figure 9 and Figures 10A to 10H illustrate methods of affixing the modular attachment 30 to the femur 32, followed by affixing the femoral component 12 to the femur 32 and the modular attachment 30. Figure 9 illustrates the necessary resection on the femur 32 , prior to the creation of the femoral recess to permit the affixing of the modular attachment 30. Figure 9 and Figures 10A to 10H do not illustrate the resection required for the modular attachment 30, but the necessary resection will be appreciated by one of ordinary skill in the art. technique. After resection is completed, as in Figure 10A, the modular fixation 30 may be affixed to the femur, as in Figure 10B. The femoral component 12 may then be affixed to the femur 32 (and modular affixation 30, if desired) by positioning and movement of the femoral component 12, as illustrated in Figures 10C to 10H. As can be appreciated from the sequence of illustrations depicted in FIGS. 10C to 10H, the femoral component 12 must be rotated or rolled into position, with initial contact beginning at the posterior region as illustrated in FIG. 10E and progressing to position. fully seated in figure 10G. This is a new deployment technique that will require some additional practice and training on current techniques.

As set forth above with reference to Figure 4A, a third type of embodiment having an extended articular surface is not modular and does not use a separate modular display 30. In such embodiments, an extended articular surface corresponding to the flanged area 36 of the modular affix 30 may be formed integrally as part of one or both condyles of the femoral component 12. Positioning of such an embodiment is illustrated with reference to Figures 11A to 11K. As may be appreciated with reference to these figures, positioning of such an embodiment also utilizes a rotary positioning technique similar to that illustrated in figures 10C to 10H. As may be appreciated with reference to Figures 10H and 11K, any of the modular or non-modular embodiments may optionally be further secured by one or more screws positioned on an anterior flange of the femoral component 12.

An advantage of the embodiment illustrated in Figures 11A to 11K is that the implantation surgeon can decide whether to use the illustrated embodiment or a traditional femoral component 12 after the anterior distal and oblique cuts have been made. This is illustrated in figures 12A to 12C. Figure 12A shows a traditional femoral component 12. Figure 12B shows one embodiment of the described femoral component 12 without an extended anterior flange. In other words, Figure 12B shows that, in some embodiments, when the femoral component is seated in the femur 32, a proximal anterior end 69 of the femoral component is configured to terminate at or near a proximal end 71 of anterior oblique section 64 ( for example, between about 0 and about 15 mm on the proximal or distal side of the proximal limit of the natural knee joint cartilage). Figure 12C, on the other hand, shows an embodiment of the femoral component 12 illustrated in Figures 11A to 11K, which includes an anterior flange 49 extending proximally to the anterior oblique cut 64. As may be appreciated by reference to the In the figures, the distal sections 62 and the anterior oblique sections 64 are essentially identical. This can be further appreciated with reference to figure 13, which shows an overlap view of figures 12A and 12B, not only showing that the distal femoral sections 62 and the anterior oblique sections 64 are identical, but also showing that the total amount of bone resected for the illustrated modality is similar to or less than the amount resected using current techniques and femoral components 12.

In a non-modular mode of the femoral component 12 as shown in Figures 11A to 11K and in a modular mode of the femoral component as shown in Figures 4A to 5D there are joints where the internal flat surfaces of the prosthesis (which when implanted, are in contact with bone) meet.

These flat surfaces, instead of joining at an acute angle, may or may not have a radius connecting the two flat surfaces. Not all flat surface junctions necessarily need a radius, and in some embodiments, none of the flat surface junctions will have radii. The flat surfaces may or may not be in exactly the same planes as in conventional knees and will provide the positioning of a non-modular surface that will provide a joint for the proximal anterior portion of the posterior femoral condyles extending to or near a plane that is a continuation of the posterior cortex of the distal femoral shaft. In embodiments in which one or more spokes are provided for the junction (s) of the internal flat surfaces of the femoral component 12, spokes 31 or corresponding curvatures may be provided for the resected bone surface of the femur, as shown in the figure. 5A. As may be appreciated by one of ordinary skill in the art, the presence of the corresponding rays 31 may assist in the rotational positioning of the femoral component 12 as illustrated in Figures 10A to 10H and 11A to 11K.

This internal configuration allows the femoral component 12 to be initially applied to the femur in a flexed position and then rotated to the fully extended position and is fully implanted as illustrated and discussed with reference to FIGS. 10Aa 10He 11Aa 11K. Screw (s) may optionally be positioned in the anterior flange (or other portion) of the femoral component 12 to firmly stabilize the component. This capability facilitates the implantation of the non-modular femoral component 12 or a modular femoral component 12 into the modular fixation 30 already implanted in the posterior femoral condyles 32.

A fourth type of femoral component 12 is illustrated in Figure 14. This type of embodiment has a femoral component 12 that replaces the distal femoral weight bearing condyles, and part or all of the anterior femoral articular surface and, in addition to some or all of the articular surface of the posterior condyles extending proximally and anteriorly to an area that is in the same plane as a continuation of the posterior cortex from a quarter to a distal third of the femur. Such an embodiment may comprise separate medial and lateral components or they may be affixed together to form a component that replaces or resurfaces the medial and lateral condyles.

Historically, many early total knee femoral components 12 did nothing with reference to the patellofemoral joint. Because a certain percentage of those patients had anterior knee pain, an anterior flange was added to the femoral component 12 to resurface the trochlea (patellar cavity). This weakened the patella and resulted in fractures in some patients. Recently, techniques for minimizing patellar pain have been developed which did not require implantation of a component. The embodiment shown in Figure 14 does not have an anterior flange which is an integral part in the condylar portion of the prosthesis. It is anticipated that such a device 12 alone in some patients may be suitable for femoral condyle replacement and allow the surgeon to treat the patellofemoral joint as he feels it is indicated. Alternatively, a separate patellofemoral joint surface or surfaces could be implanted. The patellofemoral implant (s) could be entirely detached or could be modular) and affixed to the device shown in Figure 14. In some cases, the modality Figure 14 includes the ability to affix a modular anterior flange (trochlear cavity) to the device shown in Figure. In this regard, Figures 16T to 16W (discussed below) illustrate some methods for affixing various embodiments of a modular anterior flange 57 (or modular patellofemoral component).

Embodiments of the present invention involve a femoral component 12, a tibial component 14 and / or a modular fixation 30, a shank 500 (discussed hereinafter), and / or any other suitable components each comprising a metal. , a metal alloy, a ceramic, a carbon fiber, glass, a polymer (including, without limitation, bone cement, nylon, polyethylene, polyester, polytetrafluoroethylene (Teflon®), and / or any other suitable polymer), a recovered organic material, recovered human or animal tissue, a cementless material and naturally occurring or synthetic materials used separately or in any combination of two or more such materials.

As may be appreciated with reference to the above discussion and the corresponding figures, the existing femoral components 12 currently provide an articular surface that extends only a short distance in the proximal anterior direction of the posterior condyle. For example, as can be seen with reference to Figures 2A and 8A, the articular surface at the anterior end of the posterior condyle typically extends to and replaces at most the posterior third of the posterior condyle as measured from most of the posterior portion. from the patient's original posterior condyle (or from most of the posterior portion of the femoral component 12) to a plane that is a continuation of the fourth or third distal of the posterior cortex of the femoral shaft.

In contrast, the various embodiments of the femoral component 12 illustrated in the figures and discussed above provide an articular surface extended to one or both of the medial condyle and the lateral condyle extending in a proximal anterior direction to extend across. half or more of the anteroposterior distance between most of the posterior portion of the posterior condyle and the plane, which is a continuation of the fourth to the distal third of the posterior cortex of the femoral shaft. In some embodiments, the extended articular surface extends for at least two thirds of the anteroposterior distance between most of the posterior portion (e.g., as shown by line 300 in figure 8B) of the posterior condyle and for example (as shown by line 300 in Figure 8B) which is a continuation of the fourth to the distal third of the posterior cortex of the femoral shaft. In other embodiments, the extended articular surface extends almost the entire anteroposterior distance between most of the posterior portion of the posterior condyle and the plane which is a continuation of the fourth to distal third of the posterior cortex of the femoral shaft. In still other embodiments, the extended articular surface may extend further to surround a distal portion of the posterior cortex of the femoral diaphysis, as illustrated in Figures 16A to 16D.

The extension surface, which may or may not contact the bone and is a continuation of the femoral joint surface, may be referred to as the full flexion joint. There may be a corresponding surface on the posterior edge of the tibial and / or lateral tibial joint which is not part of the tibial joint surface when the tibia is at full extension. For example, in some embodiments of the present invention, there is a corresponding surface at the posterior edge of the mediate tibial joint where the center of the mediate joint surface is more than 20% of the distance from the posterior edge of the component to the anterior edge.

[0098] The embodiment illustrated in Figure 19A shows a non-articular surface 41 posterior to the main articular surface 43. Figure 19B illustrates a full flexion articular surface 45 and an articular surface 47. The tibial full flexion joint of Figure 19B is posterior. to the main weight support joint and articulates with a specific joint area in the femoral component, the full femoral flexion joint (proximal extension 50) shown in figures 16A to 16Q and shown in a slightly shortened embodiment in figure 16E.

With further reference to Figure 16E, in some embodiments of the present invention, the femoral component articular surface 402 comprises sections of various surface radii 404, 406 and 408. Each section is provided as a means for controlling the relationship between the femoral component 53 and the tibial component (not shown) throughout the knee flexion range. However, in some embodiments, radius 406 may be constant radio station and replace radii 404 and 408.

Radius 404 is characterized as having a decreasing radius, such that a recess 410 is formed on the articular surface 402. In some embodiments, the recess 410 is configured to receive an anterior crest 420 of tibial member 14 when the joint is formed. knee is hyperextended to approximately -10 ° as shown in figure 16F. By further hyperextension, as shown in Fig. 16G, recess 410 still pushes over anterior crest 420, so that the interface between recess 410 and anterior crest 420 acts as a fulcrum between femoral component 53 and tibial component 14 Therefore, as the knee joint is hyperextended beyond approximately 10 °, the radius 404 of the articular surface 402 is offset from the tibial component 14 as shown. As this deviation increases, the dense knee joint connective tissues are tensioned, thereby limiting additional knee joint hyperextension.

Referring now to Figure 16H, a knee joint is shown in a neutral extended position of approximately 0 ° of flexion. At approximately 0 ° of flexion, spokes 404 and 406 are partially in contact with tibial joint surface 403, yet the knee joint is not fully constrained. As such, the femoral component 53 is allowed to move anteriorly and posteriorly with respect to the tibial component 14. In some embodiments, spokes 404 and 406 provide knee joint slack between approximately 0 ° and 20 ° of flexion. In other embodiments, spokes 404 and 406 provide knee joint laxity between approximately 0 ° and 40 ° of flexion.

Referring now to Fig. 161, a knee joint is shown at approximately 10 ° flexion with the femoral component 53 being anteriorly displaced relative to the tibial component 14. Fig. 16J shows a knee joint at approximately 10 ° of flexion, wherein the femoral component 53 has been posteriorly displaced from the tibial component 14. An anterior and posterior knee joint laxity, as provided by radius 404, is limited by traction in the dense connective tissues of the joint. knee and the curvatures of the opposing femoral and tibial joint surfaces 402 and 403. By providing lassitude between about 0 ° and about 20 °, the natural knee flexion mechanics are preserved as detected or experienced by the user. In some embodiments, laxity is eliminated between about 0 ° and about 20 °, thereby modifying the natural knee flexion mechanics as may be desired. This is achieved by having radii 404 and 408 replaced by radius 406.

By bending the knee joint to approximately 20 °, radius 406 is largely in contact with the tibial joint surface 403, as shown in Figure 16K. However, in some embodiments, the knee joint laxity is maintained at approximately 20 ° flexion, so that the femoral component 53 is allowed to move anteriorly (Figure 16K) and posteriorly (Figure 16L). with respect to the tibial component 14. As the knee joint is further flexed, radius 406 assumes full contact with the opposite tibial joint surface 403, thereby fully restricting anterior and posterior movement of the knee joint as shown in Figure 16M . Full contact and knee joint restraint thereafter are maintained through the remaining mean flexion movement of the joint as shown in Figures 16N and 160. In addition to approximately 110 ° of flexion, radius 408 begins to contact the surface. tibial joint 403, thereby causing a deviation of the femoral and tibial components 53 and 14, as shown in figure 16P. As the knee joint is more deviated, the proximal extension 50 maintains contact with the posterior articular feature 412 of the tibial component 14.

Referring to Figure 16Q, a representative embodiment of a unicompartmental femoral component 120 is shown. The various components of the present invention may be replaced by a single-component component as discussed below. In some embodiments, the unicompartmental femoral component 120 further comprises a decreasing radius 404 providing a recess 410 as shown in Fig. 16R. In other embodiments, the unicompartmental femoral component 120 is truncated, thereby providing recess 410 at the intersection between component 120 and the unresected anterior condylar surface of femur 32, as shown in Figure 16S.

The unicompartmental component is generally implanted to replace the weight bearing portion of the knee joint in a medium or lateral manner. The unicompartmental component may be used mediately and / or laterally as two separate femoral components and two separate tibials only on the weight bearing portion of the joint. In some embodiments, the one-compartmental component is used with two femoral components or two joined tibi, but ignoring the patellofemoral joint. In other embodiments, the unicompartmental component is used as a femoral component replacing the distal femoral mediate and lateral weight bearing portions and also a portion of or all of the patellofemoral joint with a tibial component in a separate mediate and lateral tibial component or part. . Finally, in some embodiments, the unicompartmental component is a one-piece femoral component replacing the patellofemoral joint and the middle or lateral weight bearing portion of the femur.

In some embodiments, the unicompartmental component 120 includes a full flexion femoral articular surface 50. As previously discussed, the articular surface or extension 50 is configured to provide extended contact between the unicompartmental femoral component 120 and a tibial articular surface of full flexion 55 of a tibial component during a full knee flexion. In some embodiments, a portion of the popliteal femur surface 202 is removed to accept positioning of the articular surface 50. In other embodiments, a unicompartmental component (not shown) is provided for use in conjunction with the modular full flexion femoral joint surface (not shown). Thus, in some embodiments, a first portion of the femur is prepared to receive the unicompartmental component 120, and a second portion of the femur is prepared to receive a modular full flexion femoral joint surface (not shown). As such, a combination of the unicompartmental component and the modular full flexion femoral joint surface provides a unicompartmental femoral component that is functionally equivalent to the unicompartmental femoral component 120.

[00107] In some embodiments, the unicompartmental femoral component 120 is used in conjunction with a unicompartial tibial component. In other embodiments, the single compartment femoral component 120 is used in conjunction with a full tibial component. Finally, in some embodiments, the unicompartmental femoral component 120 is used directly in conjunction with an opposite natural tibial surface.

Where permitted, an implementation of a unicompartmental femoral component 120 provides several advantages over total knee replacement procedures. For example, while an eight inch (203.2 mm) incision is typically required for total knee replacement surgery, a partial knee replacement using a unicompartmental femoral component 120 requires an approximately three inch (76.2 mm) incision. ). Thus, a benefit of a unicompartmental femoral component 120 is a diminished scar following the partial knee replacement procedure.

Other benefits of partial knee replacement include reduced recovery time, increased range of motion, and decreased overall knee damage. A total knee replacement procedure may require the patient to remain in hospital for up to four days. It may also take up to three months or more to recover from surgery. However, with a partial knee replacement procedure, typically a patient does not require more than two days of hospitalization, followed by a month of recovery. Additionally, the patient is typically able to walk unattended for a week or two following the partial knee replacement procedure.

Unlike total knee replacement procedures, insertion of the unicompartmental femoral component 120 generally preserves most ligaments, thereby providing a fuller range of motion. For example, in some partial knee replacement procedures, the anterior and / or posterior cruciate ligaments are preserved as desired. Partial knee replacement usually also results in less knee damage, because surgery is minimally invasive, thereby causing minimal damage to knee tissue, muscle and tendon.

[00111] For some partial knee replacement procedures, several methods may be implemented to address the pain and discomfort caused by patellofemoral arthritis. For example, for some partial knee replacement procedures, deflection of the opposite femoral cavity is performed. In some embodiments of the present invention, the unicompartmental femoral component 120 is designed to reproduce the natural patellofemoral joint throughout the range of motion and to facilitate tracking of the patella in the femoral cavity. In other embodiments, a combination of denervation and natural design of the unicompartmental femoral component 120 is implemented to adequately address patellofemoral arthritis.

The interaction of the full flexion femoral joint 50 and the full flexion tibial joint 55 is illustrated in Figures 20A to 20I, where Figures 20A to 20E are at 0 degree, Figure 20F is at 90 degrees, Figure 20G is 130 degrees, figure 20H is 150 degrees, and figure 20I is more than 160 degrees. Figure 20B identifies a representative position of the unresected tibial plateau 51. Figure 20C indicates a representative closing radius at a posterior portion of a femoral component 53. Figure 20D identifies a representative full flexion femoral joint 50. Figure 20E identifies a representative full flexion tibial joint 55. Figure 20H identifies a representative approach of the full flexion femoral joint 50 to the full flexion tibial joint 55 during a flexion. Figure 20I identifies a representative contact of the full flexion femoral joint 50 to the full flexion tibial joint 55 during a deep flexion.

Figures 15A to 15D illustrate the various ways in which the four previously discussed embodiments of the femoral component 12 provide an extended articular surface 48. The concept of adding more articular surface to the proximal portion of the posterior condyles of the femoral component can be realized. generally by extending the proximal portion anteriorly, until the articular surface approaches or extends beyond the plane of the posterior surface of the distal femoral shaft, if that plane were to extend distally. For example, as can be seen from FIGS. 15A to 15D, the extended articular surface 48 of each embodiment extends across the articular surface at the anterior end of one or both of the posterior medial condyle and the lateral posterior condyle. As shown in Figures 16A-16D, the articular surface may be further extended in a proximal direction from the end of the extended articular surface 48. This additional extension may be provided by a proximal extension 50. The proximal extension 50 may be an integral part. of the femoral component 12 may be a part of the modular display 30 (as discussed herein), or may be provided as a separate and additional component. In an embodiment where proximal extension 50 is provided, proximal extension 50 acts as a fulcrum that interacts with the tibia or tibial component 14 to increase the separation between the femur 32 and tibia during full functional flexion to improve Deep knee flexion. In another embodiment, the proximal extension 50 allows normal relations between the tibia and femur at full functional flexion to exist while maintaining contact between the two surfaces.

When the femoral component 12 comprises a proximal extension 50 (or a full flexion femoral joint), the proximal extension may comprise any suitable shape. Indeed, in some embodiments (as illustrated at least by Figure 16F), the proximal extension 50 extends from the femoral component 12, such that a concave hinge surface 17 (or a concave surface of any shape that is suitable for articulation against a portion of the tibia and / or the tibial component 14) is arranged at or near a proximal posterior portion of the femoral component 12. In some embodiments, Figure 16G illustrates that the proximal extension 50 comprises a first curved joint surface 19; whereas the posterior condylar surface of the femoral component (e.g., a lateral and / or mediaillary condylar surface) comprises a second curved articular surface 21, wherein the first and second articular surfaces 19 and 21 form a reverse curve.

Additionally, when the femoral component 12 comprises a proximal extension 50, the proximal extension may be disposed at any suitable location on the femoral component allowing the concave joint surface 17 to articulate against a portion of the tibia and / or the component. tibial 14, when the knee is in (or approaching) a full flexion. Further, the proximal extension 50 may also be used in connection with any suitable femoral component (e.g., as a modular unit or as an integral part) that allows the proximal extension to function as described herein.

In some embodiments, the proximal extension 50 extends from the femoral component 12, such that the concave pivot surface 17 is disposed at or near a proximal posterior portion of the femoral component (e.g., as shown in the figures). 16A to 16D). Indeed, in an illustration, Figure 16D shows that in an embodiment in which the femoral component 12 has a first internal surface 721 for contacting an anterior femoral surface and / or cut 621 at femur 32, a second internal surface 722 for contacting a front bevel cut 622 in the femur, a third inner surface 723 for contacting a distal cut 623 in the femur, a fourth inner surface 727 for contacting a rear bevel cut 627 in the femur, a fifth inner surface 724 for contacting a bending cut 624 (or a section that runs proximally and anteriorly from its distal end towards a posterior surface of the femur), the proximal extension 50 is arranged near the fifth surface 724 (e.g., so to be arranged at or near a proximal posterior portion of one or both of the condylar surfaces of the femoral component 12 and / or at or near a popliteal surface of the femoral neck).

In other embodiments, figures 16X to 16Z show that, in some cases, the proximal extension 50 is disposed on a femoral component 12 which lacks a surface (e.g., a surface 624) to contact a full length cut. 624 in the femur 32. In such embodiments, the proximal extension 50 may be arranged in any suitable location that allows it to perform its intended functions. Indeed, in some embodiments in which the femoral component 12 comprises a first inner surface 721 for contacting the anterior surface 621 of the femur 32, a second inner surface 722 for contacting an anterior bevel cut 622 in the femur, a third internal surface 723 for contacting a distal cut 623 in the femur, a fourth inner surface 727 for contacting a posterior bevel cut 627 in the femur, and an additional inner surface 728 for contacting a posterior condylar cut 628 in the femur (e.g., a cut that runs substantially parallel to or which deviates (for example, by any suitable amount less than 40 degrees) from the first inner surface 621), the proximal extension 50 is disposed proximal to surface 628.

Thus, figures 16X to 16Z show that conventional femoral components can be easily modified to include a full flexion femoral joint (e.g., by the addition of a modular and / or integral proximal extension 50). It should be noted that although Figures 16X to 16Z show the femoral component 12 having a proximal extension 50 being used to articulate and / or act as a fulcrum against the tibial component 14 (e.g., a component comprising a full flexion tibial joint), such as a femoral component that can be used to articulate against any suitable tibial articulation surface (for example, from an unresected tibia, a partially resected tibia, and / or any suitable tibial component that can articulate with the proximal extension 50). Additionally, although Figures 16X to 16Z show some embodiments in which the proximal extension is formed as an integral portion of the femoral components, in some embodiments (as described herein), the proximal extension comprises a modular unit that is affixable to the femoral component.

Thus, in some embodiments of the present invention, greater deep knee flexion is facilitated by the provision of an articular surface on the proximal anterior and / or posterior surfaces (or portions) of one or both posterior condyles of the femur. At least some of these embodiments involve an additional or enlarged articular surface in the proximal anterior and / or posterior portion (e.g., as shown in Figures 16A to 16S and 16X to 16Z) of either or both of the posterior mediate or lateral condyles of the femoral component. 12. In fact, some modalities of the femoral component 12 add an increased articular surface area to the proximal end of the posterior condyles of the femoral component 12 (e.g., in an anterior direction), so that when the patient bends his knee during a deep or full functional knee flexion, a contact between the femoral component 12 and the tibial component 14 is maintained, and greater deeper knee flexion can be obtained.

In at least some embodiments of the present invention, greater deep knee flexion may be provided or improved by modification of the tibial joint, wherein the center of the tibial articular surface of conformation of the tibial component 14 is moved posteriorly with respect to the which is currently available. Additionally, in some of these embodiments, the general shape of the lateral and / or medial tibial joint surfaces may be modified. This is illustrated with reference to figures 6A to 6D and 6J to 6K.

In some of these tibial component 14 embodiments, the condylar or articular plateau surfaces are asymmetric. Indeed, in some embodiments, the lower lateral surface side of the tibial component 14 is shorter in the anteroposterior dimension than the mediate side, and the top of the tibial component 14 may also be asymmetrical.

Anatomically, the tibial plateau typically has a larger anteroposterior dimension than it does laterally. In order to cover as much of the cut proximal tibia as possible and to avoid hanging the lateral plateau anterior or posterior, in some embodiments, the tibial component is larger in the anteroposterior dimension than it is laterally. In one embodiment, this is accomplished by moving the center of the mediate joint surface posteriorly to compensate for dimensional differences. In some cases, in order to achieve full flexion, it may be useful to have the medial center of rotation in the tibia (which is a concave segment of a sphere) later than is currently available with other designs. This allows the proximal tibia, when the knee is flexed beyond approximately 120 to 130 degrees, to be positioned anteriorly so that there is no impingement of the posterior edge or portion of the tibial joint surface on the proximal portion of the posterior mediate condyle. of the femur. Current designs of tibial components 14, which will allow the tibia to move anterior to flexion, have a non-spherical tibial articular surface or the center of rotation of the spherical articular surface is not as posterior as provided by the embodiments described below. However, embodiments of the present invention may be used in combination with any knee replacement design that allows knee flexion up to 120 ° or greater.

Currently, some available full knee tibial components 14 which have a fixed center of rotation of medium shape have the center of rotation located at a position that is around 35 to 45% of the entire anteroposterior dimension from the surface. Notwithstanding some embodiments of the tibial component 14 described herein, the center of rotation is moved posteriorly so that it is between about 18% and about 35% of the anteroposterior dimension from the wall. In such embodiments, the center of rotation may be arranged at any location between about 18% and about 35% (or any sub-range thereof) of the anteroposterior dimension of the tibial component 14, as measured at from the rear edge of the component. Indeed, in a non-limiting example, the center of rotation of the femur with respect to the tibial component is between about 20% and about 33% of the anteroposterior dimension from the posterior edge of the tibial component 14.

In the normal knee, the mediate side of the knee is restricted by the fact that, for any degree of flexion, the position of the medial femoral condyle with respect to the tibial joint surface is approximately fixed and does not move anteriorly or posteriorly by an amount. flexural range of approximately 20 to 130 degrees. In contrast, on the lateral side, except for full extension and sometimes full flexion, after around 20 to 40 degrees of flexion, the lateral femoral condyle may move anteriorly and posteriorly on the lateral tibial plateau. At full functional flexion up to 160 degrees and beyond, the lateral femoral condyle may appear to be touching only the most posterior portion of the opposite tibial plateau or may contact the most anterior plateau clearly at the flattened portion of the lateral tibial plateau.

Therefore, in tibial component 14 embodiments, the lateral tibial articular surface is basically flat in the anterior-posterior direction, except anteriorly where there is an anterior ferrule, which prevents the tibial component from rotating too far externally and allowing it to rotate too far. the lateral femoral condyle slides out of the anterior edge of the tibial component. In some embodiments, the basically flat portion of the lateral tibial joint surface may comprise between about two thirds and about seven eighths (or any subbands thereof) of the total anteroposterior dimension of the tibial component 14. In some embodiments, a slight ferrule may later be present on the side, however, provided that the fixed center of rotation is positioned as described, no ferrule is subsequently required on the side. In other embodiments, there is no anterior or posterior ferrule. In some embodiments, the lateral tibial joint surface is flat or concave when viewed in the frontal plane and, if concave, may or may not have the same radius of curvature as the opposite femoral condyle, or may have a larger radius when viewed in the frontal plane. In some cases, this flat or concave cavity is flat at the bottom when viewed in the sagittal plane, except for the anterior and posterior ends, as noted above, and is generated around a point corresponding to the center of rotation of the mediate condyle. In some embodiments, the posterolateral tibial joint may be the same as described for the posterior mediated full flexion joint. In some embodiments, the tibial articular surface may be the same as or similar to the flat articular surface described for the lateral tibial plateau. However, in some modalities, the position of the mediate joint contact is mainly mandatory, while the position of the lateral joint contact is not mandatory. Thus, the position of lateral articular contact is probably determined by the task being performed, by comfort and / or by culture.

Figures 6A to 6D and 6J to 6K depict a comparison of a tibial condylar surface 26 and a tibial condylar lateral surface 24 of tibial component 14 with some tibial component 14 embodiments as described above. Specifically, Figures 6A and 6B reflect side views of medial and side sides, respectively, of some currently available tibial components 14 while Figures 6C and 6J illustrate side views of medial sides, and Figures 6D and 6K illustrate side views of some embodiments of the tibial component 14, as discussed above. It will be appreciated that various varied configurations for the medial and lateral articular surfaces ranging from almost flat, medial and laterally to more conforming as shown in Figures 6A and 6B have been used in the past; however, it is currently believed that none has a combination of a posteriorly displaced mediate articular surface and a relatively flat lateral articular surface, or a tibial femoral full flexion joint. These configurations allow the lateral femoral condyle to move anteriorly or posteriorly on the lateral tibial joint surface as the knee flexes and extends. Other configurations may be provided so that as long as the lateral tibial articular surface permits this anteroposterior movement, the lateral tibial configuration need not be confined to a single configuration as shown in Figures 6D and 6J.

The lateral tibial joint in some modalities may not have a posterior ferrule, and in other embodiments, the posterior surface may tilt downward when accompanied by a medial tibial joint that provides flexion beyond 135 degrees.

In the prior art tibial component 14, the condylar surface has a curvature centered at a fixed point 52. The distance from the fixed point 52 (or from the low point centered curvature 52) to the edge Posterior 54 of the tibial component is approximately 35 to 45% of the anteroposterior dimension of the tibial component 14. These measurements are similar to the medial (Figure 6A) and lateral (Figure 6B) sides of the tibial component 14. Some currently available tibial components 14 have a ferrule 56.

In the tibial component embodiment 14 illustrated in FIGS. 6C and 6D, there is no tibial component ferrule 56 associated with the medial condylar surface 26. Instead, the tibial condylar surface 26 runs along a smooth arc. As the bow is generated a low ferrule may be present in some embodiments and may extend to and include the posterior tibial full flexion joint. The amount of the ferrule will be determined by the ratio of the center of rotation of the rear edge 54 of the tibial component 14. In another embodiment, however, Figure 6J shows an implementation in which the tibial component 14 (for example, on the tibial condylar surface 26). ) comprises a ferrule 56 at the end of a smooth arc.

Although the radius from the fixed point 52 to the articular surface in Figures 6A and 6C is essentially the same, in some embodiments of the present invention, the distance from the fixed point 52 (or from the low point of curvature centered at the fixed point 52) until the rear edge 54 of the tibial component 14 is shorter. Indeed, as mentioned earlier, in some embodiments, the fixed point 52 is disposed at any location between (or sub-range) approximately 18% and less than approximately 35% of the anteroposterior dimension from the posterior end of the tibial component 14, as shown. can be seen in figures 6C and 6J. For example, in some non-limiting embodiments of the present invention, the distance from the fixed point 52 to the rear edge 54 of the tibial component 14 is between about 20% and about 30% (for example, about 28% + 1.5%).

With respect to the lateral side of the tibial member 14, in the embodiment illustrated in Figures 6D and 6K, there is an anterior ferrule 58 and a small posterior ferrule 60. In alternative embodiments, the posterior ferrule 60 may be omitted as discussed above. Additionally, with respect to Figure 6J, in some embodiments, the rear ferrule 56 may be raised any amount above the lowest point (e.g., the fixed point 52) on the tibial pivot surface (e.g., the medial tibial condylar surface 26). ). In fact, in some modalities, the posterior ferrule rises between about 0.5 and about 8 mm (or any subbands) above the lowest point on the tibial condylar surface. 26 In fact, in some modalities , the posterior ferrule rises between about 2 and about 6 mm (or any subbands thereof) above the lowest point on the tibial condylar surface. 26 Moreover, in some embodiments, the posterior ferrule rises between around 3 mm and around 5 mm (or any sub-range) above the lowest point on the tibial condylar mediate surface 26.

Thus, as illustrated with reference to Figures 6A to 6D and 6J to 6K, in at least some embodiments of the present invention, a greater deep knee flexion may be provided or enhanced by modification of the tibial joint, wherein the tibial articular surface center of conformation of the tibial component 14 is moved posteriorly to what is currently available. This change alone, with some currently available femoral components, will increase the amount of flexion achieved compared to a standardized tibial component. Additionally, in some of these embodiments, the overall shape of the lateral tibial joint surface is modified. Although this modification may be used for any suitable purpose, in some embodiments, the lateral tibial articular surface is modified to allow the proximal tibia, when the knee is flexed beyond approximately 120 to 130 degrees, to be positioned anteriorly enough so that there is no impingement of the posterior edge or portion of the tibial joint surface on the proximal portion of the femoral mediate condyle. Therefore, greater deep knee flexion can be obtained. Thus, it may be appreciated that the use of a modality of the above tibial component with a conventional femoral component will facilitate greater flexion than will the use of a conventional tibial component. Similarly, using any of the above described femoral components with a conventional tibial component will facilitate more flexion than will the use of a conventional tibial component with a standardized femoral component.

One of ordinary skill in the art will appreciate that the knee (as discussed above) may include at least one of a lateral pivot and a middle pivot. Accordingly, embodiments of the present invention will be understood to be compatible with one or both of the lateral and middle knee pivot configurations. In other words, although various embodiments described above discuss the lateral tibial articular surface 24 and the mediatic tibial articular surface 26 as having specific characteristics, in some embodiments, the positioning of one or more of the aforementioned features of the lateral tibial articular surface and surface tibial joint mediai is reversed. Accordingly, the positioning of each of the features discussed above may be reversed in any suitable manner, allowing the lateral tibial articular surface (or lateral tibial condylar surface) to comprise a fixed center of rotation, and allowing the tibial articular surface mediai (or tibial condylar surface mediai) allows the femoral condyle mediai to move anteriorly or posteriorly on a tibial mediai tibial plateau of the tibial component 14. By way of non-limiting illustration, in some cases Figures 6C and 6J illustrate portions of various tibial components 14 comprising a lateral tibial condylar surface (e.g., surface 26), while Figures 6D and 6K illustrate portions of various tibial components 14 including the tibial mediaillary condylar surface (e.g., surface 24).

In some embodiments of the present invention, a greater deep knee flexion may be provided or enhanced by modification of the tibial joint, wherein the articulated surface of the tibial component is modified to encourage or limit a femoral component joint in relation to to the tibial component. Examples of this modification are shown in figures 6E to 6I.

Referring now to Figures 6E, 6F and 6I, a tibial component 14 is shown according to a representative embodiment of the present invention. In some embodiments, the tibial condylar surface 26 of the tibial component 14 is modified to include a pivoting feature. A pivoting feature is generally provided to interact in a manner compatible with an opposite pivoting surface of the femoral component. During a knee flexion, the joint surface of the femoral component interacts with the joint feature of the femoral component relative to the tibial component. Thus, in some embodiments, a joint feature is provided for knee joint control during a deep flexion.

Various types of articulation features may be used in accordance with the teaching of the present invention. For example, some embodiments of the joint feature comprise an inclined joint crest 400. Articular crest 400 is provided to interact in a manner compatible with an opposite articular surface of the femoral component. The interaction between the joint crest 400 and the femoral component joint surface affects a change in the femoral component joint movement during a deep knee flexion. Indeed, in some embodiments, an interaction between the femoral component and the articular crest 400 causes the posterior joint of the femoral component to dislocate when a knee flexion is obtained. Additionally, in some embodiments, the joint feature acts as the full flexion tibial joint.

Articular crest 400 is generally disposed on the posterior surface of the tibial component 14 in a general medial lateral direction 450. Although the articular crest may generally be disposed at any suitable angle with respect to an anteroposterior direction 460 of the surface. In some embodiments, the articular ridge 400 is disposed or positioned on the posterior surface at an angle Θ that is obtuse to an anteroposterior direction 460 of the intercondylar surface 28. In other embodiments, however, the articular ridge 400 is disposed or positioned on the posterior surface. posterior surface of an angle Θ which is acute with an anteroposterior direction 460 of the intercondylar surface 28. Generally, the angle Θ of joint crest 400 is selected to achieve a desired articular displacement of the femoral component during a deep flexion. In some styles, an angle Θ of about 0 ° to about 110 ° is selected. In some other embodiments, an angle Θ of about 0 ° to about 90 ° is selected. In still other embodiments, an angle Θ of about 10 ° to about 45 ° is selected. Additionally, in some embodiments, an angle Θ of from about 20 ° to about 35 ° is preferred. In still other embodiments, the angle Θ falls within any suitable sub-range of the aforementioned ranges. By way of illustration, Figure 6E illustrates one embodiment in which the joint crest 400 runs at an acute angle with the anteroposterior direction 460 of the intercondylar surface 28. In addition, Figure 6I illustrates a embodiment in which the joint crest 400 runs substantially perpendicular to the anteroposterior direction 460 of the intercondylar surface 28.

Articular ridge 400 may be of any suitable shape that allows the tibial component 14 to articulate against an articular surface of a femur and / or femoral component 12. In fact, although some modalities of the articular crest are substantially straight along of its length, in other embodiments, the articular ridge comprises an elongate crest that is slightly bulged (as shown in Figure 6E), which is curved along a portion of its length, which follows an outline of a posterior edge of the articular surface. 24, which follows an outline of a posterior edge of the medial condylar surface 26 (as shown in Figure 6I) that has a flexed portion, and / or is otherwise shaped to cause the posterior joint of the femoral component to displace. in the tibial component when deep flexion is achieved.

Articular ridge 400 may be positioned anywhere on the articular surface of the tibial component 14 so as to achieve a desired articular displacement of the femoral component during a deep knee flexion. For example, in some embodiments, the lateral tibial condylar surface 24 is modified to include the joint crest (not shown). In this example, any suitable amount of the joint crest (or other joint feature) may be arranged on the lateral half (or completely on the lateral condylar surface) of the tibial component 14. In fact, in some embodiments, the joint crest (or other feature) articular) is arranged in the lateral half (e.g., lateral to the central geometric axis of the intercondylar surface 28) and does not extend to the middle half of the tibial component (at least not as a single continuous articular crest).

In other embodiments, the tibial mediaillary condylar surface 26 includes the articulation feature. In these modalities, any suitable amount of the articular crest (or other joint feature) may be disposed on the middle (or completely on the middle condylar) surface of the tibial component 14. In fact, in some embodiments, the joint crest (or other feature) of the joint) is arranged in the middle half (e.g., mediated to a central geometric axis of the intercondylar surface 28) and does not extend to the lateral half of the tibial component (at least not as a single continuous articular ridge). By way of illustration, Figure 6E shows a representative embodiment in which the articular ridge 400 is arranged completely on the medial condylar surface 26.

In still other embodiments, both lateral and tibial condylar surfaces 26 and 24 include an articular ridge 400 (or other articulating feature). Although in some embodiments a single articular ridge covers the gap between the lateral and medial condylar surfaces, in other embodiments, the lateral and medial condylar surfaces each comprise a separate articular crest (and / or other articulating feature).

In some embodiments, the pivoting feature comprises a polyethylene coating or layer. In other embodiments, the polyethylene coating is strictly applied to the articular ridge 400 and is prevented from extending beyond the articular ridge 400 so as to impinge on the femur during flexion.

Referring now to Figures 6G and 6H, a tibial component 14 is shown according to a representative embodiment of the invention. In some embodiments, the tibial condylar surface 26 of the tibial component 14 is further modified to include a pivoting feature comprising a spherical articular surface 420. The spherical articular surface 420 is provided to interact compatible with an opposite articular surface of the femoral component. . In some embodiments, the interaction between the spherical joint surface 420 and the femoral component joint surface allows for unrestricted natural joint movement of the femoral component during deep knee flexion. In some embodiments, an interaction between the femoral component and the spherical articular surface 420 permits a natural posterior articulation of the femoral component when deep flexion is obtained. One of ordinary skill in the art will appreciate that the tibial component 14 can also be modified to allow a femoral joint on the lateral tibial condylar surface of the tibial component. Additionally, one of ordinary skill in the art will appreciate that the tibial component 14 may be modified to allow for a concomitant femoral joint on both the tibial mediate and lateral tibial condylar surfaces, for desired applications.

The spherical articular surface 420 may comprise a true spherical shape or may comprise any other suitable shape including, without limitation, a parabolic shape; a bulge; a convex format; a high rounded overhang; a high polygonal format; and / or any other shape suitable when projecting from an articular surface of the tibial (and / or tibial) component. One of ordinary skill in the art will appreciate that variations in the surface structure of the hinge surface 420 may be required to provide a hinge surface that is optimally configured for a specific application or use.

The spherical articular surface 420 may be positioned anywhere on the articular surface of the tibial component, so that a higher hierarchical movement is desired for the femoral component during a deep knee flexion. Indeed, in some embodiments, the lateral tibial condylar surface 24 is modified to include the spherical articular surface (not shown). In such embodiments, any suitable amount of the spherical joint surface may be disposed on the lateral half (or completely on the lateral condylar surface) of the tibial component 14. In fact, in some embodiments, the spherical joint surface is disposed on the lateral (e.g., lateral) half. to a central geometric axis of the intercondylar surface 28) and does not extend to the middle half of the tibial component (at least not as a single continuous spherical articulating surface).

In other embodiments, the tibial condylar mediate surface 26 includes the spherical articular surface (or an articulating feature). In such embodiments, any suitable amount of the spherical articular surface may be disposed on the middle (or completely on the medial condylar) surface of the tibial component 14. In fact, in some embodiments, the spherical joint surface is disposed on the middle (eg, medial) surface. to a central geometric axis of the intercondylar surface 28) and does not extend to the lateral half of the tibial component (at least not as a single continuous articular ridge). By way of illustration, Figure 6G shows a representative embodiment in which the spherical articular surface 420 is disposed completely on the medial condylar surface 26.

In other embodiments, both the tibial and lateral condylar surfaces 26 and 24 include a spherical articular surface 420. Although in some of these embodiments a single spherical articular surface covers the gap between both lateral 24 and mediate condylar surfaces 26, in both embodiments. In other embodiments, the lateral and medial condylar surfaces each comprise a separate spherical articular surface (and / or other articulating feature).

In some embodiments, the hinge feature comprises a polyethylene coating or layer. In other embodiments, the polyethylene coating is strictly applied to the spherical articular surface 420 and is prevented from extending beyond the spherical articular surface 420 so as to impinge on the femur during a flexion.

Additionally, although the pivoting feature (for example, the pivot ridge 400, the spherical pivot surface 420, etc.) is disposed posteriorly to the tibial component 14 (e.g., a tibial pivot surface), the articulation feature may be arranged at any suitable location with respect to the posterior edge of the tibial component (and / or a tibial articular surface). In fact, although in some modalities the articular feature is arranged at or extends to the posterior edge of the tibial component, in some other modalities the articular feature terminates (or decreases in elevation) anterior to the posterior edge. Indeed (as shown in Figures 6G, 6E and 6F), in some embodiments, a substantially flat, concave and / or raised pivot surface 416 is disposed between a rear portion of the pivot feature (e.g., spherical pivot surface 400 and / or spherical articular surface 420) and the posterior edge of the tibial component 14.

When the tibial component 14 comprises a unicompartmental component, the articular feature (e.g., the articular crest 400, the spherical articular surface 420, etc.) may be arranged at any suitable location on the unicompartmental component. Indeed, while in some embodiments the articulating feature is simply disposed within the confines of the unicompartmental component (e.g., the lateral or mediatic unicompartmental component), in other embodiments, the articulating feature is disposed on the articular surface (for example, the tibial condylar mediai 26 or lateral tibial condylar surface 24) of the unicompartmental component.

In some embodiments, the opposite surface of the femur and / or femoral component is modified to comprise a concave surface (not shown) configured to interface in a manner compatible with the convex spherical articular surface 420 of the tibial component. In other embodiments, the opposite surface of the femur and / or femoral component is modified to include a concave cavity (not shown) configured to interface in a manner compatible with the convex joint crest 400 of the tibial component. Also, in some embodiments, the tibial component comprises a concave surface (not shown) and the femoral component comprises a convex surface (not shown) to interact in a manner compatible with the concave tibial surface. Further, in some embodiments, the polyethylene lining (not shown) or the articular surface of the tibial component is configured to interface in a manner compatible with a desired structure, shape or feature of the opposite femoral surface thereby obtaining. normal knee function and movement throughout the knee range of motion. For example, in some embodiments, a tibial component is provided without a raised posterior portion or a hinging feature. Instead, the surgeon may elect to leave the posterior portion of the patient's tibia, which, in turn, has an interface with the femoral component to achieve normal knee function. Thus, in some embodiments, a unicompartmental femoral component is provided for achieving normal knee function.

Figures 7A and 7B depict modifications to the femoral component 12 and tibial component 14 to allow deeper knee flexion. Specifically, Figure 7A depicts a sagittal sectional view of a knee prosthesis 10 with a modified femoral component 12 and a tibial component 14. In Figure 7A, an area 102 of the femoral component 12 is removed as represented by the dashed line. This area 102 is above and between the posterior end 104 and the anterior side 106 of the posterior end 104. By removing area 10, a deeper flexion for knee prosthesis patients is partially obtainable.

Similarly, with the tibial member 14 of FIG. 7B, a medial side 25 may appear to be slightly extended in the anterior-anterior dimension anteriorly by movement of the posterior articular surface 24 and thereby having more of the tibial component anterior to the joint. posteriorly displaced mediai. This may give the appearance of having removed a posterior portion of the tibial component 14 and moved it to the anterior. A lateral side 27 of the tibial component may be shortened in the anteroposterior dimension relative to the mediate side 25 (i.e., area 100). Figure 7B illustrates the above in plan view. In other words, by posteriorly shortening the lateral side 27 (i.e., removing area 100) of the tibial component 14 and displacing the posterior mediate joint surface 24, deeper knee flexion is possible. And these modifications create the opportunity for a knee prosthesis patient to achieve deeper knee flexion than is possible with the currently available prosthetic knees.

In at least some embodiments of the invention, a larger knee prosthesis may be obtained by providing an asymmetrical femoral component 12. Asymmetrical femoral component 12 allows transfer of more than half of the force transmitted through the joint to be transferred to the mediate side, as occurs in the normal knee. Some of these embodiments are illustrated with reference to figures 17 and 18A. Figure 17 illustrates a drawing of a radiograph of a knee at a flexion of around 160 degrees. At radiography, the femur 32 is seen in the anteroposterior direction, and a femoral mediate condyle 66, a femur 32 lateral condyle 68, and a patella 70 are visible. As may be appreciated with reference to the figure, the medial-lateral width of the medial condyle articulation portion 66 is greater than the medial-lateral width of the lateral condyle 68. Specifically, in the figure, the medial-lateral width of the articular portion of the medial condyle 66. The medial condyle 66 is represented by X. As can be seen from the figure, in some embodiments, the medial-lateral width of the lateral condyle 68 is approximately 75% (or any suitable minor amount) of the medial-lateral width X of the medial condyle 66. In fact, in some embodiments, the medial-lateral width of lateral condyle 68 is any suitable amount between about 10% and about 75% of the medial-lateral width X of condyle 66. In still other embodiments, the medial-lateral width of the lateral condyle 68 is any suitable amount between about 30% and about 74% of the medial-lateral width X of the medial condyle 66. In still other embodiments, the medial-lateral width 1 of the lateral condyle 68 is any suitable amount between about 40% and about 70% of the medial-lateral width X of the middle condyle 66.

As may also be appreciated with reference to Figure 17, the center of the patella 70 is lateral with the midline of the knee.

Specifically, in the figure, the medial-lateral distance between the most middle portion of the distal end of the femur 32 and the center of the patella 70 is represented by Y. As can be seen, the medial-lateral distance between the most lateral portion of the distal end of the femur 32 and the center of the patella 70 is approximately 75% or less (73% in the figure) of Y. In some embodiments of the invention, the femoral component 12 may mimic the actual physical structure of the knee depicted in figure 17.

In these embodiments of the femoral component, as shown in Figure 18A, the articular portion of the lateral condyle in its medial-lateral width is 75% or less than the width of the medial condyle. This allows more than half of the force that is transmitted through the joint to be transmitted to the mediate side, which is what occurs in the normal knee. This also allows the patellar or trochlear cavity to be lateralized, because this distal cavity is defined by its position between the mediate and lateral condyles. In the normal knee, the patella tends to be slightly lateralized in the femur, and this lateral displacement of the cavity performs or that many conventional total knee replacements perform by external rotation of the femoral component 12 in the knee replacement. In one embodiment, condyles in the frontal plane are viewed as circular with a constant radius. The medial and lateral condyles do not have to be of the same radius, but both can be circular when viewed in that plane. When viewed in the sagittal plane, the condyles will be seen to have a posterior and anterior closure radius and may blend into the anterior flange in the modalities in which a flange is used.

Figure 18A illustrates a front view of one embodiment of a femoral component 12 according to the described embodiments. In the figure, illustrative measurements are illustrated to show features of the described embodiment and are not meant to be limiting of the features of the described embodiments. As shown in Figure 18A, the medial-lateral width of the femoral component 12 may be approximately 72 millimeters (mm). In this embodiment, the medial-lateral width of the medial femoral condylar surface 20 in the posterior portion of the posterior medial posterior condyle is approximately 32 mm, while the medial-lateral width of the lateral femoral condylar surface 22 is approximately 22 mm. Thus, in the illustrated embodiment, the medial-lateral width of the lateral femoral condylar surface 22 is approximately 69% of the medial-lateral width of the medial femoral condylar surface 20.

In the illustrated embodiment, a patellar cavity 72 is defined by the space between the medial femoral condylar surface 20 and the lateral femoral condylar surface 22. Due to the fact that the medial-lateral width of the medial femoral condylar surface 20 is larger than the medial-lateral width of the lateral femoral condylar surface 22, the patellar cavity 72 is displaced laterally, which is what occurs in the normal knee. As may be appreciated with reference to FIGS. 18A to 18C, the patellar cavity 72 may be provided at an angle as the patellar cavity 72 moves from a proximal anterior portion to a distal anterior portion to a distal posterior portion and up to and including a portion thereof. a proximal posterior portion. For example, the angle of the patellar cavity 72 in Fig. 18A, as measured from a sagittal plane, is approximately 86 degrees. In other embodiments, however, the angle of the patellar cavity may be any suitable angle which is smaller than about 90 degrees and nearly greater than about 15 degrees (or any sub-range thereof). Indeed, in some embodiments, the patellar cavity extends laterally from a distal anterior portion of the femoral component to the most proximal anterior portion of the femoral component at any suitable angle between about 40 degrees and about 89 degrees. . In still other embodiments, the patellar cavity extends at any suitable angle from about 50 degrees to about 85 degrees.

Thus, the illustrated embodiment shows how a femoral component 12 according to the embodiments of the present invention can assist in achieving deeper knee flexion and, in some embodiments, full functional flexion by providing a femoral component. asymmetrical 12. The asymmetrical femoral component 12 can assist in achieving deeper knee flexion by better simulating physiological loading and patellar follow-up. The asymmetrical femoral component 12 allows a more normal loading of the joint with the middle side assuming more of the load than the lateral side. Additionally, the asymmetrical femoral component 12 allows for a more anatomically correct lateral tracking of the patella, which may reduce the problems of patellar pain, subluxation and dislocation. One of ordinary skill in the art will readily recognize that in some embodiments, the tibial component 14 may be modified to accommodate an asymmetrical femoral component 12.

As discussed herein, at least some embodiments of the present invention involve providing deeper knee flexion capabilities, wherein the medial femoral side is relatively fixed and the lateral side slides forward and backward. While some embodiments involve a knee with a tibial component that keeps the tibial component relatively fixed at the medial side and capable of sliding on the side, other embodiments involve a knee that is relatively fixed at the lateral side and capable of sliding on the mediate side. This would apply, for example, to the tibial component.

In addition, although the additional articular surface of the femoral component could be mediate, lateral or both, at least some embodiments of the present invention involve its application for the use of tibial and femoral full flexion joints in a mediate, lateral or lateral fashion. both.

Referring now to Figures 18B and 18C, in some embodiments, an abbreviated anterior flange 610 is provided for replacing the trochlear surface or cavity 72. In some embodiments, the articular cartilage and underlying bone are optionally removed, which are typically removed with the anterodistal bevel cut. In some embodiments, anterior flange 610 is provided for compensation of an individual patient anatomy, wherein the lateral portion of the anterior condyle in a conventional prosthesis extends or rests more prominently than the bony knee condyle 200. For these anatomies, The prominent position of the conventional prosthesis attempts or otherwise separates the lateral soft tissues, which may result in decreased flexion and discomfort or pain. In some embodiments, the anterior flange 610 is provided without replacement of the anterior condyles 20 and 22 of the distal femur 210, such as by use with a patient with severe patellofemoral arthritis who would not be adequately treated with the prosthesis shown in Figures 12A, 12B, 14 and 16Q to 16S. Providing only the front flange 610 can also provide reduced cost relief and / or reduced evasion. In other embodiments, anterior flange 610 is provided in addition to replacing anterior condyles 20 and 22.

In some embodiments, the length of the abbreviated front flange 610 is too short to replace only a portion of the trochlear surface 72. In other embodiments, the length of the abbreviated front flange 610 is extended to fully replace the Trochlear surface 72. Still, in some embodiments, the anterior flange 610 is distally extended between the distal condyles 20 and 22 to a length approximately equal to the currently available non-abbreviated prosthesis flanges.

Referring now to Figure 21, a side perspective view of a knee 200 is shown. In at least some embodiments of the present invention, a greater deep knee flexion may be additionally provided, improved or improved by removing a portion of the popliteal surface 202 of the femur 210. The popliteal surface 202 may include a bone proximal to the posterior articular surfaces of the femur. condyle mediai, lateral condyle, or both mediate and lateral condyle. A resection of the popliteal surface 202 may be performed by any appropriate method known in the art. For example, in one embodiment, a portion of the tibia is first resected, thereby providing sufficient clearance to dry the required portion of the popliteal surface 230.

[00165] The amount of bone resected from the tibia, femur or both will vary from individual to individual, depending on the specific anatomy of the tibia and femur. The resected popliteal surface 230 provides additional clearance between opposing surfaces of the tibia 220 and femur 210. Specifically, the resected popliteal surface 230 prevents impingement of the posterior articular surface 250 of the tibial condyle 240 on the femur 210 during a deep flexion of the tibia 220. knee 200. As such, knee 200 can flex freely without the tibia 220 adversely adhering to or contacting any portion of the femur 210. In addition, the resected popliteal surface 230 can provide a flexion exceeding 140 °. In one embodiment, the dried popliteal surface 230 provides a flexion exceeding 160 °.

Referring now to Fig. 22, a side perspective view of a knee 200 is shown following resection of the popliteal surface 202 for provision of the resected popliteal surface 230. As previously discussed, resection of the popliteal surface 230 may be performed by any appropriate method known in the art. However, in one embodiment, a resection block 300 is used to guide a cutting device 310 in resection 230. Resection block 300 is comprised of a metallic material, similar to the previously discussed metallic materials, and includes a outer surface 312, an inner surface 314 and a slot 316. The outer surface 312 is contoured and adapted to substantially overlap the lateral and middle condyles of the femur 210; however, in some embodiments, the guide would cover only the medial or lateral condyle. Inner surface 314 includes a plurality of inclined surfaces that mirror the resected and shaped surfaces of the lateral and medial condyles of the femur 210. Thus, the inner surface 314 of the resection block 300 is adapted to fit the resected surfaces 62, 64 and 366 of the femur 210. The recessed resection block 300 and the femur 210 are further secured by a plurality of fasteners 320, such as screws. This may not be necessary in all cases. Fasteners 320 are required only to secure the guide firmly to the femur. In some embodiments, the interaction between the guide and the femur is such that the guide is held firmly in place without fasteners. In another embodiment, the guide is held in place by any means to facilitate accurate resection of the above mentioned area of the femur.

The interaction between the resection block inner surface 314 300 and the resected surfaces 62, 64 and 366 of the femur 210 accurately aligns the slot 316 with the popliteal surface 202 of the femur 210. The slot 316 generally comprises an opening 330 and an inner opening 332. The outer opening 330 comprises a first width that is slightly larger than the width 338 of the cutting device 310. As such, the outer opening 330 is adapted to receive the cutting device 310 in a compatible manner. The inner opening 332 is positioned exactly adjacent to the popliteal surface 202 and comprises a second width that is larger than the first width and approximately equal to the desired width of popliteal resection 230. Thus, the slit walls 334 taper inwardly from the second opening to the first opening, thereby providing a wedge slot 316.

Cutting device 310 may include any device compatible with slot 316. In one embodiment, an oscillating blade 340 is provided. Swing blade 340 includes a spigot 342, a cutting head 344 and an anvil 346. Spigot 342 generally comprises a surface that is adapted to fit compatible and securely into a tool (not shown) capable of moving the blade 340 relative to the resection block 300 and the femur 210. The cutting head 344 generally comprises a plurality of teeth suitable for removing the desired portions of the popliteal surface 202 for resection 230. The stop 346 generally comprises a hardware, a clamp or some other feature that provides a point in blade 340 that is wider than the first opening 330 of slot 316. As such, stop 346 is unable to enter slot 316, thereby limiting the depth to which it is allowed. that blade 340 enters slot 316. Thus, stop 346 acts as a depth gauge for controlling or limiting the final depth of popliteal resection 230. In a In the embodiment, the stop 346 further comprises an adjusting screw whereby the stop 346 is loosened and repositioned on the blade 340 to change the depth to which the blade 340 is allowed to enter slot 316. In another embodiment, cutting device 310 is a cutter bit having a stop 346 for limiting the cutter depth of cut.

Referring now to Fig. 22A, a lower side perspective view of the femur 210 and the resection block 300 is shown. In one embodiment, the resection block 300 includes a first slot 316 and a second slot 318 separated by a connecting portion 326 of the resection block 300. The first slot 316 is positioned adjacent to the medial condyle 66 of femur 210 and the second slot 318 is positioned adjacent to the lateral condyle 68. Each slot is positioned at a different height from the natural asymmetrical positions of the middle and lateral condyles 66 and 68. Thus, the first and second slots 316 and 318 of the resection block 300 are adapted to optimally resect the popliteal surface 202 of the femur 210 with respect to the asymmetrical positions of condyles 66 and 68. In another embodiment, the first and second slits 316 and 318 are positioned at equal heights so as to provide a parched popliteal surface 230 that is symmetrical without consideration of asymmetrical condyles 66 and 68. In yet another embodiment, the positioning of the external aperture 3 30 with respect to the inner opening 332 of the first slot 316 is different from the positioning of the outer opening 330 with respect to the internal opening 332 of the second slot 318. As such, the radius of each wedge opening 316 and 318 is different and the contours or shapes resulting from the resected popliteal surface 230 to the first and second slits 316 and 318 will be asymmetric. In another embodiment, the connecting portion 326 is eliminated, thereby providing a single guide slot. In this embodiment, the upper and lower portions of the guide are held in place relative to one another by lateral and media bridges. The lateral and media bridges maintain the position of the upper and lower portions of the guide, as well as the definition of the outer edges of the slot. In another embodiment, the lateral and media bridges are used for providing multiple slits in the guide.

Referring now to FIGS. 22 and 22A, the plural resection 230 is effected by inserting the cutting device 310 into the first slot 316 and removing the popliteal surface 202 to the desired depth as limited by the stop feature. 346 and the wedge slot radius limitations 316. The wedge shape of slot 316 allows the cutter 310 to be pivoted along the wedge radius, wherein the contact between the stop 346 and the outer opening 330 acts as a fulcrum to the wedge radius. The resulting resection 230, therefore, comprises a radial surface configured and shaped to receive the femoral component 12 of the knee prosthesis. Following formation of popliteal resection 230, screws 320 or other stabilization methods and resection block 300 are removed from the femur 210.

Referring now to Figures 23 and 23A, a lateral cross-sectional view of a knee 200 is shown following a popliteal surface 230. The femoral component 12 of the knee prosthesis may be modified to correspond to the portion 230 for resection 230 of the popliteal surface 202. For example, in one embodiment, a portion 212 of the femoral component 12 of the knee prosthesis is extended and contoured to rest on the resected portion 230 of the popliteal surface 202. As such, the posterior articular surface 250 the tibial plateau 240 of the tibia 220 compatible and smoothly interacts with the extended portion 212, thereby allowing knee 200 to achieve deep flexion. Further, the interaction between the posterior articular surface 250 and the extended portion 212 prevents the posterior articular surface 250 from adhering to an end surface 214 of the femoral component and displacing the femoral component 12 in an anterior direction during a deep flexion. In some embodiments of the present invention, the extended portion 212 is used in conjunction with a tibial implant having a spherical or convex mediate partial side. In another embodiment, the extended portion 212 is used in conjunction with any knee replacement allowing a knee flexion of 120 ° or greater. For example, in one embodiment, a femoral component of a knee prosthesis system is modified to include a metal part constituted by the rear of the back portion of the component to provide an extended portion 212 compatible with the tibial component of the knee system. knee prosthesis.

In some embodiments of the present invention, including the extended portion 212, the femoral component 12 does not include an anterior flange or any provision for an anterior patellofemoral joint, as shown in Figures 15B and 16B (and 12B) above. As such, the lack of an anterior flange allows component 12 to be impacted on the femur in a relatively conventional manner, except that in some embodiments component 12 is implanted after further rotation with respect to a conventional prosthesis. Additionally, the femoral component 12 may be used without a patellofemoral joint implant. In some embodiments, component 12 is used with a modular flange affixed to the proximal end of the anterior oblique condyle of the condylar implant to provide an anterior femoral joint to the patella to prevent patellar subluxation and to be used in cases of high patella. In another embodiment, the femoral component 12 is used with unaffected anterior patellofemoral implant joints. In still other embodiments, a separate femoral flange is used for a patella, which does not have an implanted component. In still other embodiments (as shown in Figure 15E), the femoral component 12 comprises a truncated front flange 213.

When the femoral component 12 comprises a truncated front flange 213, the truncated front flange may extend for any suitable distance (for example, to any suitable distance from about 0 to about 15 mm) at any given length. one of the proximal side or distal side of a proximal limit of the articular cartilage, which is a physiological marker that would be recognized by one of skill in the art. Similarly, in some embodiments in which the femoral component 12 comprises a truncated anterior flange 213, the truncated anterior flange may extend proximally by any suitable amount in front of an anterior proximal end 71 of anterior oblique section 64 (and / or proximal joint cartridge limit) in a prepared femur 32 (for example, between about 0 mm and about 15 mm, between about 1 mm and about 10 mm, as little as about 2 mm and around 5 mm, or any appropriate sub-range of the distances mentioned above).

In some embodiments, the femoral component 12 further comprises a modular patellofemoral component 57 (or a modular anterior flange) as shown in Figure 16T. The modular patellofemoral component 57 is generally configured to mate compatible with the femoral component 12 in an adjustable manner. For example, in some embodiments, the modular patellofemoral component 57 comprises a pin 59 which is sized and slidably inserted into a femoral component cavity or socket 13. The sliding interaction between the pin 59 and the socket 13 permits infinite adjustment of modular patellofemoral component 57 with respect to femoral component 12 as shown in Figure 16U.

[00175] The modular nature of the femoral component 12 and patellofemoral component 57 provides a personalized fit of the prosthesis to the patient. For example, in some embodiments, a patellofemoral component 57 is selected based on an anatomical need or aspect of the patient. In other embodiments, a femoral component 12 and a patellofemoral component 57 are selected based on a mechanical need for this feature for the patient. Still, in some embodiments, a patellofemoral component 57 is selected to more accurately match a parched surface of the patient's femur. Accordingly, some embodiments of the present invention comprise a plurality of modular patellofemoral components 57 which are interchangeably coupled to the femoral component 12 as may be required or desired to suit a patient's needs.

[00176] The modular nature of the femoral component 12 and patellofemoral component 57 further facilitates the process of knee prosthesis adjustment. For example, in some embodiments, a structural configuration of a unitary femoral component may preclude installation or may require additional bone to be resected from the patient's femur to allow installation. Accordingly, some embodiments of the present invention provide a method for fitting to a patient with a knee prosthesis, wherein the femoral component 12 of the knee prosthesis is initially fitted and attached to a dried surface of a patient's femur. The modular patellofemoral component 57 is then coupled or otherwise affixed to the femoral component 12 and adjusted 61 to accommodate the patient's specific anatomy. Once the position of the modular patellofemoral component 57 is optimized, component 57 is attached to the patient's femur.

Referring now to Fig. 16V, a detailed view of a femoral component socket 13 embodiment 12 and modular patellofemoral component pin 59 is shown. In some embodiments, socket 13 further comprises a tapered opening. Tapered opening 63 allows up and down adjustments 65 of modular patellofemoral component 57 relative to a fixed position of femoral component 12. In some embodiments, tapered opening 63 still allows lateral adjustments 67 of modular patellofemoral component 57 relative to to a fixed femoral component position 12. Thus, the tapered aperture provides an infinite adjustment of modular patellofemoral component 57 with respect to a fixed position of the femoral component 12. Still, in some embodiments, pin 59 is tapered (not shown), thereby providing additional adjustment of the patellofemoral component 57 with respect to the femoral component 12 as may be desired.

In addition to the illustrated embodiments discussed above, the patellofemoral component 57 and the femoral component 12 may be modified in any suitable manner that allows the two components to be affixed to a femur 32. In fact, in some embodiments, rather than including a pin and socket coupling, the two components are coupled to each other in any other suitable manner, including, without limitation, through the use of a butt joint, an overlap joint, an overlap joint, a knockout joint. , snap and snap, a dovetail joint, a hinge, a flexible member, and any other suitable type of joint or combination of joints, which allows the modular patellofemoral component 57 to be coupled to the femoral component 12.

In some embodiments, the patellofemoral component 57 and the femoral component 12 are coupled by a butt joint. Although such a butt joint may have any suitable feature, in some embodiments, one of the components (e.g., the patellofemoral component 57 or the femoral component 12) comprises a convex surface, while the other (e.g. the femoral component 12 or the patellofemoral component 57) respectively comprises a concave surface. By way of illustration, Figure 16W shows a representative embodiment in which the femoral component 12 comprises a convex surface 101 that engages with (i.e. confines) a concave surface 103 of the patellofemoral component 57. In such embodiments, the rotational interaction between the convex surface 101 and the concave surface 103 allows virtually infinite adjustment of the modular patellofemoral component 57 with respect to the femoral component 12.

When the patellofemoral component 57 and the femoral component 12 are coupled by a butt joint (or any other suitable joint), the surface between the patellofemoral component 57 and the femoral component 12 (e.g., the convex surface 101 and the concave surface 103) can have any suitable feature that allows two components to be connected to each other. Indeed, although in some embodiments the surfaces between the two components are smooth, in some embodiments, these surfaces are textured to allow cement (or another adhesive) to firmly bond to the two components. Although the surfaces between the components may be textured in any suitable manner, in some embodiments such surfaces are porous, rough, knurled, comprise frames, comprise ridges, comprise recesses, comprise protuberances, and / or are otherwise textured to maintain cement (ie any other suitable adhesive) and / or bone growth.

Referring now to Figure 23A, a cross-sectional side view of a knee 200 is shown following resection of the popliteal surface 230, wherein the femoral component 12 is used in conjunction with a tibial component. 14. In some embodiments of the present invention, the femoral component 12 described above is used in conjunction with a conventional tibial component 14 having the posteriorly displaced center of the tibial joint. In another embodiment, the femoral component 12 is used in conjunction with a tibial component 14 which has the center of the tibial joint in a position corresponding to the designs currently available. In addition to occupying or coating the dried popliteal surface 230, the extended portion 212 may include additional features for modifying the position of the tibia and femur during full flexion.

For example, in one embodiment, the extended portion 212 is modified to rotate the tibia relative to the femur with the knee in full flexion. In another embodiment, the extended portion 212 is modified to prevent rotation of the tibia relative to the femur with the knee in full flexion. In yet another embodiment, the extended portion 212 is modified to include a spherical surface at its upper or most proximal portion. As such, this spherical surface allows the tibia to rotate relative to the femur at full flexion. In some embodiments of the present invention, it may be desirable to have the spherical hinged surface with a corresponding concave surface in the femoral full flexion joint. Such a concavity provided medial-lateral stability, would provide area contact between the femoral and tibial components, and would decrease the wear of polyethylene on the prosthesis. Referring again to Figure 23, in some embodiments of the present invention, the femoral component 12 is used in conjunction with an unresected posterior portion of the patient's own tibial plateau for articulation with the extended portion 212.

Referring now to Figures 24 to 28, some embodiments of the tibial member 14 are further modified to include a stem 500 generally affixed to the lower anterior surface of the tibial member 14. As shown in Figure 24, the anterior positioning of the nail 500 is calculated to compensate for and decrease the compressive load applied to the posterior tibia during a knee joint flexion. In some embodiments, as a compressive load is applied to the posterior tibia, the stem 500 forms an interface with the inner surface 520 of the tibial anterior cortex 418, thereby preventing at least one rotation, sinking, and / or subsidence of the tibial component. 14 with respect to the tibia 220. Thus, the shape, size, angle and positioning of shank 500 are selected to obtain a desired interface between shank 500 and inner surface 520.

In some embodiments, the rod 500 is bent or otherwise shaped to closely approximate the contours of a portion of the inner surface 520, as shown in Figures 24 and 25. In other embodiments, the rod 500 is tapered, such that the rod surface portions contain several portions or areas of the inner surface 520, as shown in Figure 26. In still other embodiments, rod 500 is extended so that a tip portion 530 of rod 500 contacts inner surface 520. The rod 500 may further include tapered fins 540 to increase the stability of the rod 500 while under compressive loads. In still some other embodiments, the stem 500 comprises an adjustable connection 550 whereby the stem 500 is adjusted to accommodate the individual anatomy of the patient as shown in Figure 28A. In some embodiments, the rod 500 further comprises an adjustable tip 560, whereby the length of the rod 500 is adjusted to accommodate the individual anatomy of the patient. For example, in some embodiments, tip 560 is adjustable coupled to shaft 570 via a set of threads 580. In other embodiments, tip 560 is slidably coupled to shaft 570, wherein the position of tip 560 at The shaft ratio 570 is maintained by a set screw, a mechanical foil or an adhesive (not shown).

Thus, rod 500 can generally comprise any shape, size, length or angle necessary to accommodate the patient's needs. Additionally, rod 500 may comprise any suitable material. In fact, in some embodiments, rod 500 is metal. In other embodiments, the shank 500 is made from a plastic, wherein the plastic shank can be trimmed at the time of surgery to allow optimal adjustment.

In some embodiments, rod 500 comprises a modular rod that is interchangeable with one or more rods of a varying size (e.g., length, circumference, diameter, volume, etc.) and / or shape (e.g., angle , curvature, taper, etc.). In this manner, a single tibial component 14 may be modified such that its stem 500 is capable of contacting the inner surface 520 of the tibial anterior cortex 518 of a variety of tibias having a different size and / or shape. For example, in some embodiments in which the tibial component 14 is being placed in a relatively short tibia, a relatively short modular stem is affixed to the tibial component, such that a portion (e.g., a tip) of the stem is able to contact an inner surface of the anterior cortex of bone. In contrast, in some embodiments in which the tibial component is being attached to a relatively long tibia, a relatively long modular shaft is attached to the tibial component.

Where rod 500 comprises a modular rod, the modular rod may connect to the tibial member 14 in any suitable manner, including without limitation through the use of one or more threaded connectors, friction fittings, adhesives, fasteners ( screws, dowels, pins, rivets, tabs, etc.), mechanical connectors, and / or other mechanisms that allow one of a variety of rods to be connected to the tibial component. By way of illustration, Figure 28B shows a representative embodiment in which the lower surface 590 of the tibial member 14 (e.g., a tibial member comprising a polymer hinge surface 593 and a metal base 597) comprises a connector 599 (e.g. for example, a socket) that is configured to frictionally fit a modular rod 501 (e.g., through a spline member 505 that is sized and shaped to be inserted into connector 599 as seen on a replacement rod 510).

When rod 500 comprises a modular rod (e.g. rod 501), the modular rod may be used in any suitable manner. Indeed, in some embodiments, one or more modular rods (or even test rods, such as rods made of a disposable material, rods having a smaller diameter to reduce unnecessary damage to the medullary cavity, autoclavable rods, etc.). are coupled and / or removed from the bottom surface 590 (e.g., connector 599) until the rod of proper size and / or shape is found. At this point, the desired stem is permanently connected to the tibial component (e.g., through cement, one or more fasteners, mechanical fittings, etc.).

Where rod 500 comprises a modular rod (e.g. rod 501), modular rods of various sizes and shapes may be sold in any suitable manner, including, without limitation, separately and / or in sets.

Additionally, when the rod 500 comprises a modular rod (e.g., rod 501), the various modular rods may be configured to extend any suitable distance from the lower surface 590 of the tibial member 14. In some embodiments , the modular shanks (and / or some non-modular shank modalities) are configured to extend (when affixed to the lower surface 590 of the tibial component 14) for any suitable distance between about 1 cm and about 20 cm. from the lower surface 590. In other embodiments, the modular rods are configured to extend from about 3 cm to about 15 cm from the lower surface of the tibial component 14. In still other embodiments, the modular rods are configured to extend from about 5 to about 10 cm from the lower surface of the tibial component. In still other embodiments, the modular shanks are configured to extend within any suitable sub-range of the extension lengths mentioned above.

When the tibial component 14 includes the stem 500 (e.g., a modular stem or a permanent stem that is configured to contact the internal surface 520 of the tibia or the anterior tibial cortex 518), the lower surface 590 of the component The tibial can contact the tibia in any appropriate manner. Indeed, although the lower surface of the tibial component may be adequately contoured, in some embodiments, the lower surface of the tibial component 14 is substantially flat (e.g., as shown in Figure 24).

Additionally, when the lower surface 590 of the tibial component 14 is substantially flat, the proximal end of the tibia may be cut to any suitable angle, and the lower surface 590 of the tibial component may have an appropriate angle to allow it to attach to the tibia. . In one example, the lower surface of the tibial component 14 is slanted, and the proximal end of the tibia is cut so that the lower surface of the tibial component inclines (with respect to a longitudinal geometric axis of the tibia) distally from the rear edge 595 of tibial component toward front edge of component 598 (see, for example, Figure 24). In one example, the lower surface 590 is slanted, and the proximal end of the tibia is cut so that the lower surface of the tibial component inclines (with respect to a longitudinal geometric axis of the tibia) distally from the front edge of component 598 to rear edge of component 595. In yet another example, the bottom surface of tibial member 14 is configured so that the bottom surface runs substantially perpendicular to a longitudinal tibial axis 220.

In still other embodiments (not shown), the tibial member 14 lacks a general stem 500. In such embodiments (as well as in embodiments in which the tibial component 14 comprises a modular shank 501 or a non-modular shank), the tibial component may be affixed to a tibia in any suitable manner, including without limitation through the use of cement ( and / or another adhesive); one or more screws, bolts, pins or other fasteners; any other suitable connection mechanism; and / or any suitable combination thereof. In this regard, in some embodiments in which the tibial component lacks a stem, the lower surface 590 of the tibial component comprises one or more types of frames, recesses, knurled, features (e.g., tubercles, holes, end-end grooves). dovetail, etc.), and / or any other surface structures or features that allow cement (and / or bone) to securely affix to the lower surface of the tibial component.

In some embodiments, a femoral component 600 is provided having an anterior extension 602 which generally replaces a resected anteroproximal portion of the anterior condyles 610, as shown in Figure 29A. In some embodiments, the anteroproximal portion of the anterior condyles 610 is prepared by resection of the anterior condyle surface to the proximal limit 612 of the articular cartilage. As such, essentially all anterior articular cartilage is removed from the dried femur 32. In other embodiments, however, the anterior condyle surface of the femur is resected to any distance at (or any sub-range of) around 0 mm to around 15 mm on the distal or proximal side of the proximal limit 612 of the articular cartilage. In a non-limiting example, the anterior condyle surface of the femur is resected to between about 1 mm and about 6 mm on the distal or proximal side of the proximal limit 612 of the articular cartilage. In another non-limiting embodiment, the anterior surface of the femur is resected proximally to any amount less than about 15 mm from the proximal limit 612 of the articular cartilage.

[00195] In some embodiments, the anterior articular cartilage is removed while removing little or no other bone anteriorly. In other words, in some embodiments, the femoral component 600 essentially replaces the entire anterior articular cartilage, but little or no anteriorly shaped bone. Thus, in some embodiments, the only bone removed is a subchondral bone near the cartilage and any bone needed to allow a component to fit the distal end of the femur. Thus, in some embodiments, the femoral component 600 is capable of terminating (or adjacent to, for example, between about 0 and about 15 mm (or any suitable sub-range thereof) either from the distal or proximal side. furthermore, in some embodiments, a desiccated distal end of the femur 32 is fitted with a femoral component 600, wherein a patellar force against the femur (in extension) is substantially, if not completely, femoral. deleted to have replaced the anterior articular cartilage with which the patella normally articulates. Thus, in some embodiments, the resected anteroproximal portion of the anterior condyles 610 is replaced by an anterior condylar extension 602, thereby providing a new surface 604 against which the patient's wall may articulate.

As shown in Fig. 29A, in some embodiments, the femoral component 600 lacks an anterior flange (as discussed above), so that the femoral component substantially terminates at or distally (e.g., within about 0 mm and around 15 mm, or any sub-range thereof) from the proximal limit 612.

In some embodiments, the new articular surface 604 provides a substantially smooth transition between the femoral component 600 and the femur 32 at (or near) the proximal limit 612. Further, by removing only the articular cartilage and the underlying subchondral bone and porous structure of the femur 32, a smaller, less expensive femoral component 600 may be provided which also results in a less invasive implantation for the patient. Moreover, by allowing more bone to be preserved anteriorly in the femur, the femoral component 600 may allow faster, less complicated femur preparation than can be done with some competent femoral prosthesis.

[00198] In some embodiments, femoral preparation and implantation of the femoral component 600 are performed using surgical instruments common to standard knee systems and procedures. In other embodiments, standardized surgical instruments are used for making all desired cuts for the distal femur; however, in some embodiments, the standard anterior femoral section is not made. The standard anterodistal femoral section guide with most systems is typically suitable for removal essentially of all anterior cartilage to the proximal limit 612. Thus, there is no significant increase in instrument costs for the implementation of the femoral component 600, as opposed to a standard femoral component.

Also, since anterodistal condylar sections for the femur 32 may comprise standard cuts for adjustment of a standard femoral component, in some embodiments, a surgeon need not predetermine the use of the femoral component 600 or a standard femoral component until he has completed all femoral sections except for the anterodistal section, since this section is approximately in the same plane as the anterior femoral cortex. If the surgeon wishes to implant the femoral component 600, the surgeon will cut the anteroproximal portion of the posterior condyles 625 using a non-standard cutting guide. The standard anterodistal cut essentially removes all anterior cartilage to the proximal limit 612. Conversely, if the surgeon wishes to implant a standard femoral component, the surgeon will make the standard anterior cut necessary to accommodate the implantation of a standard femoral implant.

In a non-limiting example of a dried femur 32 suitable for use with the femoral component 600, Figure 29A shows some embodiments in which the femur 32 is dried to include an anterior bevel cut 622 (or an anterior oblique cut, see Figure 12C), a distal cut 623, a rear bevel cut 627, a rear condylar cut 628, and a full flex cut 624 (e.g., a cut extending proximally and anteriorly). from the posterior condylar cut 628 and / or toward a popliteal surface and / or a posterior surface on the femur axis).

The interior profile surfaces 620 of the femoral component 600 may be designed to match the interior profile of any conventional standard femoral component. In some embodiments, however, the inner-surface surfaces of opposing surfaces (for example, the inner surface 722, which has an interface with the front bevel cut 622 and the inner surface 724, which has an interface with the cut full flexion 624) of the femoral component are exactly parallel or (in some cases) substantially parallel to allow for pressure adjustment (including, without limitation, one without cement) or a cemented application of femoral component 600 to dry surfaces (eg , 622, 623, 624, 627 and 628). In other embodiments, the inner profile surfaces of the opposing surfaces (e.g. 722 and 724) differ from each other (or in parallel to each other) by more than about 45 °. In still other embodiments, however, opposing surfaces (e.g. 722 and 724) diverge by less than about 45 °. In still other embodiments, however, the o-surfaces (e.g. 722 and 724) diverge by less than about 45 °. In fact, in some embodiments, opposite surfaces diverge from each other by about 0 ° and about 45 °. In still other embodiments, opposite surfaces diverge from each other by about 3 ° and about 25 °. In still other embodiments, opposite surfaces diverge from each other by between about 5 ° and about 10 °. In still other embodiments, the opposing surfaces diverge from each other by any suitable sub-range of any of the aforementioned ranges (e.g., between about 4 ° and about 8 °). Additionally, although opposite surfaces (e.g. 722 and 724) may diverge in any suitable direction, in some embodiments, when the femoral component 600 is affixed to a femur 32, the opposing surfaces (or at least a portion of opposite surfaces) differ from each other as the surfaces run proximally.

The femoral component 600 may be affixed to the femur 32 in any suitable manner. In fact, although in some modalities the femoral component is configured to be rolled into the femur, in other modalities the femoral component is slid over the femur without rolling. In the latter embodiments, the femoral component may be slid into the femur in any suitable manner. In a non-limiting example, where opposing surfaces (e.g. 722 and 724) diverge as they run distally into a femur 32, opposing surfaces are forced to separate slightly to allow the compressor to be slid on and off. adjusted with femoral pressure. In this example, once the femoral component is in place, the opposing surfaces are allowed to return to their original position, which may help to keep the femoral component in place in the femur. In another example, where opposite surfaces (e.g. 722 and 724) diverge as they run proximally into a femur 32 (e.g., giving the femur a slightly wedge-like feature), the femoral component 600 is slid over. and adjusted with pressure to the femur.

When the femoral component 600 is slid over the femur 32, the femoral component may be slid to any suitable angle with respect to a longitudinal geometrical axis of the femur axis allowing the femoral component to replace a desired portion of the articulating surfaces. Femur In some embodiments, where the femoral component is slid into the femur, it is slid at an angle Θ (with respect to a longitudinal geometric axis 626 of femur 32, as shown in Figure 29A) between about 30 ° and around 55 °. In other embodiments, the femoral component is slid over the femur at an angle of about 30 ° to about 45 °. In still other embodiments, the femoral component 600 is slid into the femur at any angle that falls into any suitable combination or sub-range of the aforementioned angle ranges.

The femoral component 600 may be affixed to the femur 32 in any suitable manner, including through the use of cement (i.e. any suitable adhesive); one or more screws; pins or other mechanical fasteners; a press fit (eg a friction fit with or without cement); and / or any other known or novel method for affixing a prosthesis to a femur. In some embodiments, however, the femoral component is simply cemented (as mentioned above) to the femur. In still other embodiments, one or more surfaces of the femoral component 600 affixing to the femur 32 comprise a texture (e.g., a porous texture, frames, recesses, and / or other features) that allows bone to grow on the surface. Textured

The femoral component 600 may be modified in any suitable manner. In fact, although in some embodiments the femoral component is configured to replace all articulated surfaces of a femur (for example, in a full femoral knee replacement), in other embodiments, the femoral component is configured to be used in a femoral knee replacement. unicompartmental femoral knee. When the femoral component is used in a unicompartmental knee replacement, the component may be used at any suitable location (for example, medially and / or laterally in the femur).

In another example of how the femoral component may be modified, in some embodiments, the femoral component comprises a full flexion joint 50 (as discussed above and as shown in Figure 29A). In another example, however, Figures 29B and 29C show that in some embodiments, the femoral component 600 optionally lacks the full flexion joint. In this example, Figs. 29B shows that in some of these embodiments, a posterior portion of the femur 32 may be removed so that the bone confines and substantially corresponds to the shape of the proximal end 631 of femoral component 600. In contrast, Figure 29C shows that in some embodiments, because of the natural shape of a patient's femur 32 or because the surgeon removes a posterior portion of the femur 32 (as illustrated by dashed line 634), the posterior portion of the femur 32 is not confined. with the proximal end 631 of the posterior portion of femoral component 600.

In yet another example (discussed above), the full flexion joint 50 is added to the femoral component 600 as a modular u. In yet another example, the femoral component 600 replaces a popliteal femur surface 32. In yet another example, the femoral component is configured to receive a modular anterior flange 57 (as discussed above).

Thus, as discussed herein, embodiments of the present invention involve knee prostheses. In particular, the present invention relates to systems and methods for providing deeper knee flexion capabilities, more particularly in performing one or more of the following: (i) providing a larger articular surface area to the femoral component of a knee prosthesis, with a modification of or flexion affixing to the femoral component of a knee prosthesis, which, when integrated with a patient's femur and an appropriate tibial component, results in full functional flexion; (ii) the provision of modifications in the internal geometry of the femoral component and femoral bone sections associated with implantation methods; (iii) the provision of asymmetrical lower surfaces in the tibial component of the knee prosthesis and uniquely positioned joint surfaces to facilitate full functional flexion; (iv) asymmetrical femoral condylar surfaces with a lateralized patellar (trochlear) cavity to more closely replicate a physiological loading of the knee and to provide better patella follow-up; and (v) resecting essentially all anterior femoral articular cartilage and underlying bone, but no additional bone and replacing it with a femoral component that does not have an anterior flange as seen in contemporary prostheses.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. For example, one of ordinary skill in the art will appreciate that the methods and systems of the present invention may be modified for use in unicompartmental knee arthroscopy procedures and prostheses. The methods and systems of the present invention may still be used on the lateral side of the knee, rather than or in combination with the mediate side. Thus, the embodiments described are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is therefore indicated by the appended claims rather than the preceding description. Any changes that come about in the meaning and equivalence of the claims should be encompassed within their scope.

Claims (20)

1. A femoral knee replacement component, comprising: a femoral component having an articular surface, wherein the articular surface comprises an anterior condylar extension that is configured to replace an anterior articular cartilage of a femur, and wherein the anterior extension is configured to terminate about 15 mm from a proximal limit of the anterior articular cartilage of the femur. Femoral component according to Claim 1, characterized in that the femoral component further comprises a full flexion joint comprising a concave articulating surface disposed near a proximal and posterior surface of the femoral component. Femoral component according to Claim 1, characterized in that it further comprises a first inner surface and a second inner surface, wherein the first and second inner surfaces diverge to be parallel to each other between about 0 ° and 0 °. around 45 °. Femoral component according to Claim 3, characterized in that the first inner surface and the second inner surface of the femoral component differ from each other by less than about 20 °. Femoral component according to claim 1, characterized in that the anterior condylar extension further comprises a surface which is configured to articulate against a patella. Femoral component according to Claim 1, characterized in that it comprises a full femoral knee prosthesis. Femoral component according to claim 1, characterized in that it comprises a unicompartmental femoral knee prosthesis. Femoral component according to Claim 3, characterized in that the femoral component is configured to be applied to the femur by sliding the femoral component to the resected surface of the femur at an angle between about 30 and about 55 ° C. degrees with respect to a longitudinal geometric axis of the femur. Femoral component according to claim 5, characterized in that the femoral component is configured to be applied to the femur by cementing the femoral component to the resected femur surface. 10. Method for normalization of patellar and patellofemoral follow-up forces in one knee during a deep flexion, the method characterized by the fact that it comprises: preparing a knee to receive the femoral component by resection of bone and articular cartilage from from a distal portion of the femur, wherein the articular cartilage and bone are removed from the anteroproximal portion of the anterior femoral condyles to about 0 mm and about 15 m from a proximal limit of the articular cartilage; positioning the femoral component on the resected surfaces of the femur so that a more anterior extension of the femoral component terminates at about 15 mm from the proximal limit; and the fixation of the femoral component to the prepared femur. A method according to claim 10, further comprising preparing the femur for receiving the femoral component by resecting the bone from a popliteal femur surface. Method according to claim 10, characterized in that the femoral component comprises a first inner surface and a second inner surface, and wherein the first and second inner surfaces diverge to be parallel to each other about one another. 0o and around 45 °. Method according to claim 10, characterized in that the femoral component comprises a first inner surface and a second inner surface, and wherein the first and second inner surfaces diverge to be parallel to each other between approximately 5 ° and 1 °. approximately 10 °. Method according to Claim 12, characterized in that the first inner surface corresponds to an anterior chamfer cut in the femur. Method according to claim 12, characterized in that the second inner surface corresponds to a full flexion cut into an anteroproximal portion of a posterior knee condyle. Method according to claim 10, characterized in that the femoral component comprises a full femoral knee prosthesis. Method according to claim 10, characterized in that the femoral component comprises a unicompartmental femoral knee prosthesis. Method according to claim 10, characterized in that the step of fixing the femoral component to the prepared femur comprises adjusting with pressure the femoral component in the prepared femur. Method according to claim 10, characterized in that the femoral component further comprises a full flexion joint comprising a concave joint surface disposed near a posterior and proximal surface of the femoral component. A method of replacing a distal portion of a femur, the femur comprising: preparing the femur to receive the femoral component by resection of the bone and articular cartilage from a distal portion of the femur, wherein the articular cartilage and bone are removed from an anteroproximal portion of the anterior femoral condyles to about 0 to about 15 mm from a proximal limit of the articular cartilage; positioning of the femoral component on the resected surfaces of the femur, so that a first inner surface and a second inner surface of the femoral component differ in parallel with each other between about 0 ° and about 45 ° and such that a anterior condylar extension of the femoral component ends at about 0 to about 15 mm to the proximal limit; and the fixation of the femoral component to the prepared femur.