Distal femur substitute
By designing the distal condyle curved surface of the distal femoral substitute as a plane, increasing the contact area with the tibial rotary member gasket, the problem of unstable flexion movement and high full extension force in the prior art is solved, and better stability and service life are achieved.
Patent Information
- Application Number
- CN202421473311.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-25
- Publication Date
- 2025-05-23
- Estimated Expiration
- 2034-06-25
AI Technical Summary
The existing distal femoral prosthesis is unstable during flexion and activity, and the force required for full extension is greater, and the contact between the ankle surface and the polyethylene liner is likely to cause wear and affect service life.
A distal femoral substitute was designed, and the curved radius of the distal condyle curved surface of the distal condyle is much larger than the curved radius of the posterior condyle curved surface, making the distal condyle curved surface almost planar, increasing the contact area with the tibial rotary piece gasket, sharing the weight, and better adapting to the human skeleton structure through the design of the outer surface of the condyle body.
Improves stability and weight sharing ability of distal femoral substitutes in standing positions, reduces flexion instability, and extends the reduction of strength required for full stretching, improving service life.
Smart Images
Figure CN222889078U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of medical devices, in particular to a distal femur replacement component. Background Art
[0002] Artificial knee replacement refers to a surgery that replaces the knee joint surface that has been severely damaged and cannot perform normal functions with an artificial prosthesis, thereby eliminating pain, correcting knee deformities, restoring knee joint stability and mobility, improving knee joint mobility, and improving the patient's quality of life.
[0003] The hinged knee joint is a commonly used prosthesis in artificial knee replacement surgery. The hinged knee joint prosthesis usually uses a hinge mechanism to connect the femoral component to one or both of the load-bearing component and the tibial component, so as to constrain the components of the knee joint prosthesis and mechanically connect them together. The articular surface of the existing distal femoral prosthesis is poorly adapted to the human bone structure, resulting in instability in flexion activities, and the force required for full extension is large, which is not conducive to the patient's activities and recovery. In addition, the ankle surface of the existing distal femoral prosthesis is in full contact with the polyethylene liner, which is easy to wear the polyethylene liner when the knee joint rotates, affecting the service life of the polyethylene liner. Utility Model Content
[0004] The utility model aims to provide a femur distal end replacement part which has good adaptability to the human body bone structure and can share the load-bearing capacity in the standing position.
[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0006] A distal femoral replacement comprises a femoral condyle body, the femoral condyle body having two condyles spaced apart along the coronal plane, an intercondylar fossa defined between the two condyles, the outer surface of the condyle body being divided into an anterior condylar curved surface, a distal condylar curved surface and a posterior condylar curved surface along the sagittal plane, the distal condylar curved surface transitionally connecting the anterior condylar curved surface and the posterior condylar curved surface, wherein the curved surface radii of the anterior condylar curved surface, the posterior condylar curved surface and the distal condylar curved surface increase successively.
[0007] In one embodiment, the radius of curvature of the distal condyle curvature is at least ten times the radius of curvature of the posterior malleolar curvature.
[0008] In one embodiment, the outer surface of the condyle is divided into a lateral condylar surface, a middle condylar surface and a medial condylar surface along the coronal plane, and the middle condylar surface transitionally connects the lateral condylar surface and the medial condylar surface, wherein the radii of the lateral condylar surface, the medial condylar surface and the middle condylar surface increase sequentially.
[0009] In one embodiment, the radius of curvature of the mid-condylar curvature is at least ten times the radius of curvature of the medial condylar curvature.
[0010] In one embodiment, in the standing position, the condylar distal curved surface contacts the shim on the tibial rotation component, and at least half of the condylar distal curved surface contacts the shim.
[0011] In one embodiment, in the standing position, at least two-thirds of the area of the distal curved surface of the condyle is in contact with the top surface of the spacer.
[0012] In one embodiment, the femoral condyle body is provided with a threading hole at the connection between the femoral condyle body and the two condyle bodies, respectively. The threading hole passes through the femoral condyle body obliquely from the inner side of the condyle body to the middle and rear section of the outer side.
[0013] In one embodiment, the femoral condyle body also has an axial hole that passes through the two condyles along the coronal plane, wherein the axial hole of one of the condyles is provided with a non-circular expansion slot at the end away from the other condyle, and the aperture of the expansion slot is larger than the aperture of the axial hole.
[0014] In one embodiment, a stop groove is disposed on two opposite side walls of the expansion slot, and the stop groove is composed of two convex strips protruding from the inner wall of the expansion slot.
[0015] In one embodiment, the upper portion of the femoral condyle body is provided with a screw hole for connecting a femoral cavity extension rod.
[0016] The utility model adopts the above technical solution, and has the beneficial effect that the radius of the condyle distal curved surface in the outer surface of the ankle body of the distal femoral replacement provided by the utility model is much larger than the radius of the condyle posterior curved surface, so that the condyle distal curved surface is almost a plane. When in the standing position, the condyle distal curved surface can have more contact area with the gasket on the tibial rotation member, which can better share the patient's weight. At the same time, the outer surface of the condyle can better adapt to the human bone structure, so that consistent ligament growth can be produced, flexion instability can be reduced, and ligament balance can be promoted. At the same time, it can also extend the quadriceps moment arm, improve the efficiency of the quadriceps, and reduce the force required for full extension. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 A schematic perspective view of a distal femoral replacement is shown.
[0018] Figure 2 A schematic diagram showing the cooperation of a distal femoral replacement and a tibial component is shown.
[0019] Figure 3 A side view of a distal femoral replacement is shown.
[0020] Figure 4 A schematic diagram of a pin is shown. DETAILED DESCRIPTION
[0021] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings so that the purpose, features and advantages of the present invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.
[0022] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.
[0023] Unless the context requires otherwise, throughout the specification and claims, the word "comprise" and variations such as "include" and "have" should be construed in an open, inclusive sense, ie, should be interpreted as "including, but not limited to."
[0024] References throughout the specification to "one embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.
[0025] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise.
[0026] In the following description, in order to clearly demonstrate the structure and working mode of the utility model, many directional words will be used for description, but the words "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", "down", etc. should be understood as convenient terms and should not be understood as restrictive terms.
[0027] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0028] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0029] The present embodiment provides a distal femoral replacement, including a femoral condyle body 11, the femoral condyle body 11 matches the anatomical structure of the human femoral condyle, the femoral condyle body 11 has two condyles 12 spaced apart along the coronal plane, and an intercondylar fossa 13 is defined between the two condyles 12; the femoral condyle body 11 also has an axial hole 14 penetrating the two condyles 12 along the coronal plane. The upper part of the femoral condyle body 11 is used to connect the femoral cavity extension rod, the femoral cavity extension rod is used to be inserted into the medullary cavity of the femur, and the femoral cavity extension rod is threadedly connected and fixed to the femoral condyle body 11. The femoral cavity extension rod can be selected as a biological type or a cement type according to actual needs, wherein the cement type femoral cavity extension rod can be used in conjunction with bone cement.
[0030] The outer surface of the condyle 12 of the femoral condyle body 11 is divided into an anterior condyle curved surface 121, a distal condyle curved surface 122 and a posterior condyle curved surface 123 along the sagittal plane direction, and the distal condyle curved surface 122 transitionally connects the anterior condyle curved surface 121 and the posterior condyle curved surface 123 to form the outer surface of the condyle in the sagittal plane direction. Among them, the curvature radius of the anterior condyle curved surface 121 is the smallest, the curvature radius of the posterior condyle curved surface 123 is the second largest, and the curvature radius of the distal condyle curved surface 122 is the largest.
[0031] Preferably, the curvature radius of the condylar distal curved surface 122 is much larger than the curvature radius of the condylar posterior curved surface 122, so that the condylar distal curved surface 122 is almost a plane. Figure 2 In the standing position, the condylar distal curved surface 122 can contact the gasket 21 on the tibial rotation member 2, and there can be more contact area between the condylar distal curved surface 122 and the gasket 21, which can better share the patient's weight. At the same time, the gasket 21 also has a limiting effect. In the standing position, the condylar anterior curved surface 121 is interfered by the gasket 21 and can no longer perform hyperextension. The gasket 21 can satisfy the function of sharing pressure without affecting the physiological characteristics of normal joint movement. It should be noted that the term "far greater than" here usually refers to an exponential level, that is, greater than or equal to 10 times the radius of the curved surface.
[0032] See also Figure 2, the condylar distal curved surface 122 of the condylar body 12 is substantially in contact with the top surface of the gasket 21 in the sagittal plane direction, and the condylar distal curved surface 122 is substantially in contact with the top surface of the gasket 21 in the coronal plane direction, from which it can be concluded that most of the condylar distal curved surface 122 is in surface contact with the top surface of the gasket 21. Preferably, in the standing position, at least half of the area of the condylar distal curved surface 122 is in contact with the top surface of the gasket 21, and more preferably, at least two-thirds of the area of the condylar distal curved surface 122 is in contact with the top surface of the gasket 21.
[0033] See also Figure 3 The outer surface of the condyle 12 of the femoral condyle body 11 is divided into a lateral condyle curved surface 124, a middle condyle curved surface 125 and a medial condyle curved surface 126 along the coronal plane direction. The middle condyle curved surface 125 transitionally connects the lateral condyle curved surface 124 and the medial condyle curved surface 126 to form the outer surface of the condyle in the coronal plane direction. Among them, the curvature radius of the lateral condyle curved surface 124 is the smallest, the curvature radius of the medial condyle curved surface 126 is the second largest, and the curvature radius of the middle condyle curved surface 125 is the largest. The curvature radius of the middle condyle curved surface 125 is much larger than the curvature radius of the medial condyle curved surface 126, so that the middle condyle curved surface 125 is almost a plane. The "much larger" mentioned here usually refers to more than an exponential level, that is, greater than or equal to 10 times the curvature radius.
[0034] See also Figure 2 In the standing position, the condylar mid-surface 125 can contact the gasket 21 on the tibial rotation member 2, and the condylar mid-surface 125 and the gasket 21 can have a larger area in contact, which can better share the patient's weight. In addition, the outer surface of the condylar body 12 can better match the human bone structure, allowing consistent ligament growth, reducing flexion instability, and promoting ligament balance. At the same time, it can also extend the quadriceps moment arm, improve quadriceps efficiency, and reduce the force required for full extension.
[0035] See also Figure 1 A threading hole 15 is provided at the connection between the femoral condyle body 11 and the two condyles 12. The threading hole 15 obliquely penetrates the femoral condyle body 11 from the inner side of the condyle body 12 to the middle and rear section of the outer side. The oblique threading hole can better suture the soft tissue, and the patient can recover faster and better after the operation.
[0036] See also Figure 1One of the axial holes 14 of the condyle 12 is provided with a non-circular expansion slot 141 at the end away from the other condyle 12. The aperture of the expansion slot 141 is larger than the aperture of the axial hole 14, and a groove for accommodating the end of the pin 3 is formed at one end of the axial hole 14. The polygonal expansion slot 141 is preferably a regular polygon, for example, a square with four sides in the present embodiment. The expansion slot 141 can cooperate with the polygonal end of the pin 3 accommodated in the axial hole 14 to prevent rotation. Preferably, a backstop groove 142 is further provided on the two opposite side walls of the expansion slot 141. The backstop groove 142 is composed of two convex strips protruding from the inner wall of the expansion slot 141. The backstop groove 142 can be used to accommodate a retaining spring to prevent the pin from escaping from the axial hole 14. Or refer to Figure 4 One end of the pin shaft 3 is connected to two spaced-apart spring sheets 31, one end of the spring sheet 31 is connected to the end of the pin shaft 3 and extends in the axial direction of the pin shaft 3, and the other end of the spring sheet 31 is provided with a stop member 32, and the edge of the stop member 32 is provided with a retaining spring portion 33 extending radially along the pin shaft 3. The retaining spring portion 33 can be inserted into the retaining groove 142 of the shaft hole 14 through the elastic deformation between the two spring sheets 31, so that the retaining spring portion 33 at the edge of the retaining member 32 plays a role similar to a retaining spring, which can effectively play a role in preventing retreat.
[0037] The preferred embodiments of the present invention have been described in detail above, but it should be understood that after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention. These equivalent forms also fall within the scope defined by the claims attached to this application.
Claims
1. A distal femoral replacement, comprising a femoral condyle body, wherein the femoral condyle body has two condyles spaced apart in a coronal plane direction, and an intercondylar fossa is defined between the two condyles, characterized in that: The outer surface of the condyle is divided into an anterior condyle curved surface, a distal condyle curved surface and a posterior condyle curved surface along the sagittal plane, and the distal condyle curved surface transitionally connects the anterior condyle curved surface and the posterior condyle curved surface, wherein the curved radii of the anterior condyle curved surface, the posterior condyle curved surface and the distal condyle curved surface increase successively.
2. The distal femur replacement according to claim 1, characterized in that: The radius of curvature of the distal condyle curved surface is at least ten times the radius of curvature of the posterior malleolar curved surface.
3. The distal femur replacement according to claim 1, characterized in that: The outer surface of the condyle is divided into a lateral condyle surface, a middle condyle surface and a medial condyle surface along the coronal plane, and the middle condyle surface transitionally connects the lateral condyle surface and the medial condyle surface, wherein the radii of the lateral condyle surface, the medial condyle surface and the middle condyle surface increase sequentially.
4. The distal femur replacement according to claim 3, characterized in that: The curvature radius of the middle condyle curvature surface is at least ten times the curvature radius of the medial condyle curvature surface.
5. The distal femur replacement according to claim 2, characterized in that: In the standing position, the condyle distal curved surface contacts the gasket on the tibial rotation component, and at least half of the area of the condyle distal curved surface contacts the gasket.
6. The distal femur replacement according to claim 5, characterized in that: In the standing position, at least two-thirds of the area of the distal curved surface of the condyle is in contact with the top surface of the spacer.
7. The distal femur replacement according to claim 1, characterized in that: The femoral condyle body is respectively provided with a threading hole at the connection position with the two condyles, and the threading hole obliquely penetrates the femoral condyle body in the middle and rear section direction from the inner side of the condyle body to the outer side.
8. The distal femur replacement according to claim 1, characterized in that: The femoral condyle body also has an axial hole that penetrates the two condyles along the coronal plane, wherein the axial hole of one condyle is provided with a non-circular expansion slot at the end away from the other condyle, and the aperture of the expansion slot is larger than the aperture of the axial hole.
9. The distal femur replacement according to claim 8, characterized in that: A stop groove is arranged on two opposite side walls of the expansion slot, and the stop groove is composed of two convex strips protruding from the inner wall of the expansion slot.
10. The distal femur replacement according to claim 1, characterized in that: The upper part of the femoral condyle body is provided with a screw hole for connecting the femoral cavity extension rod.