Knee femoral prosthesis and knee prosthesis system
By designing intersecting or non-intersecting through holes and curved inner surface transitions in the knee femoral prosthesis, the problems of unstable positioning and large osteotomy volume in the prior art have been solved, achieving smaller osteotomy volume and better initial stability, reducing patient injury and fracture risk.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING MONTAGNE MEDICAL DEVICE CO LTD
- Filing Date
- 2025-06-11
- Publication Date
- 2026-07-03
AI Technical Summary
In current total knee replacement surgery, the instability of femoral prosthesis positioning and excessive osteotomy lead to severe postoperative damage and high risk of fracture for patients, and deviations in the orientation of the positioning hole affect initial stability.
Design a femoral prosthesis for the knee joint with at least two through holes to receive fasteners. The axes of the through holes intersect or are not parallel, the axis of the fastener is at an angle to the axis of the through holes, and the inner surface is a curved transition, which reduces the amount of bone resection and improves initial stability.
It enables more flexible prosthesis fixation strategies, reduces osteotomy, minimizes patient injury, lowers the risk of postoperative fracture, and improves the initial stability of the prosthesis.
Smart Images
Figure CN224441524U_ABST
Abstract
Description
Technical Field
[0001] This application relates to an orthopedic medical device, and more particularly to a femoral prosthesis for use in total knee arthroplasty and a knee prosthesis system including the same. Background Technology
[0002] Artificial joint replacement surgery, as the ultimate treatment for advanced knee joint diseases, has gradually become a mature and effective treatment method. It mainly includes total knee replacement and unicompartmental knee replacement. In the case of total knee replacement, because the femoral prosthesis needs to be replaced, osteotomy is required on the distal (end) side of the femur.
[0003] Currently, primary total knee arthroplasty typically requires creating multiple planar or single-curved osteotomy surfaces in the distal femur. Therefore, multi-planar osteotomy is necessary on the distal femoral condyle to accommodate the femoral prosthesis. Due to limitations in femoral prosthesis design, using multiple planar osteotomy surfaces results in a large amount of osteotomy, causing significant trauma to the patient, hindering subsequent revision surgery, and increasing the risk of postoperative femoral condyle fracture.
[0004] Furthermore, to secure the femoral prosthesis, pre-drilled positioning holes are typically used on the osteotomy surface to receive positioning posts formed on the prosthesis. In current femoral prosthesis technology, these positioning posts are usually pre-fabricated on the prosthesis; therefore, the orientation of the positioning holes needs to match the positioning posts to achieve the intended positioning of the femoral prosthesis. However, in practice, due to various factors such as the surgeon's technique, there is a high possibility that the actual orientation of the positioning holes may deviate from their intended orientation. This can cause problems with the matching and installation between the positioning holes and the positioning posts, thus affecting the positioning and initial stability of the femoral prosthesis.
[0005] Therefore, the industry needs a femoral prosthesis for the knee joint that allows for more flexible positioning, facilitates achieving more ideal initial prosthesis stability, and / or minimizes osteotomy. Utility Model Content
[0006] In order to at least partially overcome the aforementioned disadvantages of the prior art and achieve at least one of the aforementioned objectives, this application provides a femoral prosthesis for the knee joint.
[0007] The knee femoral prosthesis includes: an anterior portion configured for fitting onto the distal anterior condylar osteotomy surface of the femur; a posterior portion configured for fitting onto the distal posterior condylar osteotomy surface of the femur; a middle portion configured to connect the anterior and posterior portions; and at least two through-holes configured to receive fasteners to secure the knee femoral prosthesis to the distal femur, wherein the at least two through-holes include through-holes whose bore axes intersect or are non-planar with each other. Alternatively, at least one of the at least two through-holes is provided with internal threads.
[0008] According to one embodiment of this application, the knee joint femoral prosthesis is divided into an active area configured to withstand frictional forces and non-active areas located on both sides of the active area, wherein at least two through holes are disposed in the non-active areas.
[0009] According to another embodiment of this application, the fastening axis of the fastener received in the at least two through holes forms an angle with the hole-forming axis of the corresponding through hole. Preferably, the included angle is 0° to 20°.
[0010] According to another embodiment of this application, the inner surface of the front portion, the inner surface of the rear portion, and the inner surface of the middle portion constitute a smooth inner surface of the knee joint femoral prosthesis along the direction of movement of the knee joint femoral prosthesis, and at least one of them is in the form of a curved surface.
[0011] Furthermore, the curved surface and the adjacent inner surface are tangentially aligned. Preferably, the curved surface is spherical. Alternatively, the curved surface has different curvatures along the direction of movement from the femoral prosthesis of the knee joint and at least one other direction intersecting the direction of movement.
[0012] Furthermore, this application also provides a knee joint prosthesis system. The knee joint prosthesis system includes: at least one of the aforementioned knee femoral prostheses configured for fitting distal to the femur of a patient; a knee tibial prosthesis configured for fitting proximal to the tibia of the patient; and a spacer disposed between the knee femoral prosthesis and the knee tibial prosthesis, and configured to have a first side and a second side opposite to each other, the first side being fixed to the knee tibial prosthesis, and the second side being configured to mate with the knee femoral prosthesis.
[0013] By utilizing the femoral prosthesis of the knee joint according to this application and the knee joint prosthesis system including the prosthesis, a more targeted prosthesis fixation strategy can be provided based on the patient's own femoral condition, thereby achieving better initial prosthesis stability. Furthermore, by utilizing the femoral prosthesis of the knee joint according to this application and the knee joint prosthesis system including the prosthesis, the amount of osteotomy can be minimized, thereby reducing the degree of harm to the patient, facilitating later revision surgery, and reducing the risk of postoperative femoral condyle fracture. Attached Figure Description
[0014] The accompanying drawings illustrate, by way of example, several embodiments of the knee femoral prosthesis according to this application. The embodiments shown in the drawings are merely exemplary and are not intended to limit the specific structure of the subject matter of this application to these embodiments. In the drawings, similar or identical reference numerals are used to refer to similar or identical elements or components. In the drawings:
[0015] Figure 1 This is a three-dimensional schematic diagram of a knee joint femoral prosthesis based on existing technology.
[0016] Figure 2 This is a frontal stereoscopic view of the knee joint femoral prosthesis according to this application, which is fitted onto the distal femur.
[0017] Figure 3 yes Figure 2 The diagram shows a rear-view stereoscopic view of the femoral prosthesis of the knee joint.
[0018] Figure 4 Is in Figure 3 The diagram shows the assembly of the femoral prosthesis and fasteners in the knee joint, as shown in the diagram.
[0019] Figure 5 Is with Figure 4 A similar view is shown in which the femoral prosthesis and fasteners of the knee joint are in a disassembled state.
[0020] Figure 6 This is a top-view three-dimensional schematic diagram of the femoral prosthesis of the knee joint according to this application. Detailed Implementation
[0021] The following detailed description, in conjunction with the accompanying drawings, is provided. It should be noted that, for the purposes of brevity and ease of understanding, the following descriptive notes focus primarily on the structures related to the improvements of this application, and do not describe the complete structure and assembly relationships of all components or parts involved. However, this does not imply that the component or part does not have or cannot have structures not described in detail herein. Those skilled in the art will be able to understand the structural details of structures not described in detail.
[0022] Furthermore, in the specific descriptions in this article, the directional terms "front," "back," "inner," "outer," "far," and "near" mentioned in this article are all based on their meanings in human anatomy.
[0023] Figure 1 A three-dimensional schematic diagram of a femoral prosthesis for the knee joint according to the prior art is shown. As described in the background section, in current total knee arthroplasty, a distal femoral osteotomy is typically required to fit the replaced femoral prosthesis. Conventionally, this involves creating an anterior condylar osteotomy surface, a posterior condylar osteotomy surface, and an anterior osteotomy surface located between the two in the distal femur. Each of these three osteotomy surfaces is generally planar, or at least one of them may be composed of a plurality of sequentially contiguous planes.
[0024] like Figure 1 As described above, in the femoral prosthesis 80 according to the prior art, an anterior bone-fitting surface 81, a posterior bone-fitting surface 82, and an anterior bone-fitting surface 83 located between and connecting the two are formed on its inner surface. These bone-fitting surfaces are configured to match and fit with the anterior condyle osteotomy surface, the posterior condyle osteotomy surface, and the anterior bone-fitting surface of the femur (not shown in the figure), respectively. The anterior bone-fitting surface 81 and the posterior bone-fitting surface 82 are both depicted as consisting of two intercontinental planes.
[0025] On the anterior bone-attaching surface 83 and on both sides of the intercondylar fossa 84, there are positioning posts 85 extending from and perpendicular to the anterior bone-attaching surface 83 toward the medial side of the femoral prosthesis 80. These posts are used to cooperate with positioning holes pre-made on the anterior osteotomy surface of the femur to achieve proper positioning of the femoral prosthesis 80 to the anterior end of the femur.
[0026] Using the above-mentioned femoral prosthesis for the knee joint according to the prior art, the structure of the femoral prosthesis inevitably presents at least the following disadvantages:
[0027] Firstly, the planar osteotomy method requires consideration of potential damage to nerves and blood vessels in the anterior femur, necessitating local osteotomy to avoid these areas. Therefore, it is more complex and limited in its implementation, and involves a relatively larger amount of osteotomy, posing a risk of postoperative femoral condyle fracture and hindering postoperative recovery.
[0028] Secondly, positioning holes for receiving the femoral prosthesis need to be pre-drilled on the anterior osteotomy surface of the femur. To ensure proper fitting of the femoral prosthesis, the exact position of the positioning pin relative to the medial and lateral condyles requires careful consideration. This demands a certain level of operational precision from the surgeon. Otherwise, problems such as the femoral prosthesis failing to fit or poor initial stability may arise.
[0029] In order to solve at least one of the above problems and reduce or even eliminate the above disadvantages, this application provides a femoral prosthesis for the knee joint.
[0030] See Figure 2 and Figure 3 The images show a frontal and rear stereoscopic view of the knee femoral prosthesis according to this application in use.
[0031] like Figure 2 and Figure 3 As shown, the knee femoral prosthesis (hereinafter referred to as "femoral prosthesis") 10 according to this application includes an anterior portion 11, a posterior portion 12, and an intermediate portion 13 connecting the anterior portion 11 and the posterior portion 12, wherein the anterior portion 11, the posterior portion 12, and the intermediate portion 13 are configured to match the anterior condylar osteotomy surface, the posterior condylar osteotomy surface, and the anterior end osteotomy surface of the femur, respectively.
[0032] To achieve better initial stability of the femoral prosthesis 10 to the anterior end of the femur, the femoral prosthesis 10 is provided with two through holes 141 and 142 (marked as follows). Figure 3 (See figure). As is known to those skilled in the art, the femoral prosthesis 10 can be divided into an active area and a non-active area. The active area is configured for frictional engagement with a mating component (e.g., a gasket disposed between the femoral and tibial prostheses, not shown in the figure), while the non-active area is typically located on either side (medial and lateral) of the active area and is not affected by this frictional engagement. To avoid interfering with the mating movement between the femoral prosthesis 10 and the mating component, through holes 141 and 142 are both located within the non-active area. Although two through holes are depicted in the figure, this application is not limited thereto. As those skilled in the art will understand, other numbers of through holes, such as three or more, may be used where applicable, as long as they meet the positioning requirements and do not impede the aforementioned frictional engagement movement.
[0033] In order to achieve better initial stability of the femoral prosthesis, such as Figure 4 and Figure 5 As shown, the hole-forming axes L1-L1 and L2-L2 of through holes 141 and 142 are not parallel to each other. In other words, the hole-forming axes L1-L1 and L2-L2 intersect each other, and more preferably, they are skew-planar, as shown in the figure. Although in Figure 4 and Figure 5 The fastening axes (i.e., their own axes) of the fasteners (e.g., externally tapped screws) B1 and B2, which are fitted into the through-hole, are depicted as collinear with the hole-forming axis. However, in practice, the fastening axis of the fastener and the hole-forming axis of the through-hole receiving it can form an angle. This angle can be, for example, 0° to 20°. This arrangement provides physicians with some flexibility in choosing a prosthesis fixation strategy. However, in the case where the fastening axis and the hole-forming axis are not collinear, preferably, the fastening axes of the two fasteners B1 and B2 in the in-place state are still intersecting or non-plane.
[0034] Alternatively, at least one of the through holes 141 and 142 may be internally tapped to better define the direction of the fastening axis of the fastener passing through it, thereby better achieving the initial stability of the femoral prosthesis 10 relative to the anterior end of the femur. Typically, the fastener can be a locking screw commonly used in orthopedic surgery.
[0035] See Figure 6 , Figure 6 A top perspective perspective view of the femoral prosthesis of the knee joint according to this application is shown. To reduce the amount of osteotomy, the inner surfaces 11s of the anterior portion 11, 12s of the posterior portion 12, and 13s of the middle portion 13 of the femoral prosthesis 10 of this application are configured along the direction of movement of the femoral prosthesis 10 (e.g., XX). Figure 6 The arrows in the diagram indicate the surface extending from the front 11 to the rear 12, forming a smooth inner surface. (As shown in the diagram...) Figure 6 As shown, inner surfaces 11s, 13s and 12s are connected sequentially and smoothly transition at the connection point.
[0036] According to one embodiment of the femoral prosthesis of the knee joint of this application, at least one of the inner surfaces 11s, 13s, and 12s is a curved surface, and this curved surface is tangentially connected to other adjacent inner surfaces, without any plane-to-plane connection, thereby avoiding the formation of non-smooth joints at the joints and achieving the purpose of reducing osteotomy. Preferably, the inner surfaces 11s, 13s, and 12s are all curved surfaces, and more preferably, they are multi-curvature surfaces. The term "multi-curvature surface" means that the inner surface has different curvatures along the movement direction XX of the femoral prosthesis 10 and along at least one other direction intersecting the movement direction XX.
[0037] Taking the inner surface 13s of the intermediate portion 13 as an example of a multi-curvature surface, the inner surface 13s can be composed of multiple sub-surfaces that abut against each other. At least one of these sub-surfaces may have a different curvature from the other sub-surfaces. Different curvatures include cases where the sign (curvature direction) and / or the value (curvature) are different. Nevertheless, the multi-curvature surface composed of these multiple sub-surfaces (i.e., the inner surface 13s itself) is still a surface that smoothly transitions along the direction of movement XX of the femoral prosthesis 10. The above description of the inner surface 13s of the intermediate portion 13 also applies to the inner surfaces 11s and 12s.
[0038] Alternatively, the inner surface 11s of the front portion 11, the inner surface 13s of the middle portion 13, and the inner surface 12s of the rear portion 12 may each or together constitute part of a sphere, or at least one of them may be a combination of a plane and a curved surface (preferably, a multi-curvature surface).
[0039] Although the composition of the inner surface of the knee prosthesis according to this application has been described, this application is not limited thereto. Those skilled in the art can conceive of various other inner surface compositions to better meet the needs of relevant applications, depending on practical requirements.
[0040] Using the femoral prosthesis of this application, after the corresponding preparation of the femoral osteotomy surface is completed, the selected femoral prosthesis can be directly attached to the femoral osteotomy surface without performing a pre-drilling operation on the femoral osteotomy surface. Then, the fasteners B1 and B2 with external tapping can be directly fixed to the femoral anterior end after osteotomy by passing through the through holes 141 and 142, thereby completing the fixation of the femoral prosthesis to the femoral anterior end.
[0041] The assembly process of this femoral prosthesis is simple, and the angle between the fastening axis of the fastener and the extension axis of the through hole can be changed according to the actual femoral osteotomy situation, thereby ensuring the initial stability of the femoral prosthesis relative to the femur while achieving a more flexible fixation operation.
[0042] Alternatively, after fastener assembly is completed, bone adhesive can be filled between the femoral prosthesis and the femur to further ensure the stability of the fit between the two.
[0043] This application also provides a knee joint prosthesis system, comprising any of the above-described femoral prostheses, a tibial prosthesis for fitting to the proximal tibia, and a spacer. The spacer is disposed between the femoral and tibial prostheses and has one side that mates with the femoral prosthesis and the opposite side that is fixed to the tibial prosthesis.
[0044] Although several embodiments of this application have been described with reference to the accompanying drawings, as will be understood by those skilled in the art, various modifications can be made to the above embodiments without departing from the scope defined by the appended claims. The above embodiments are provided merely as examples to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Features or elements described in one embodiment may be incorporated into another embodiment unless they contradict existing features or elements in another embodiment. Furthermore, the specific wording of features and the possible use of reference numerals in the appended claims are not intended to limit the scope of protection claimed.
Claims
1. A knee femoral prosthesis, characterized in that, The knee joint femoral prosthesis includes: The anterior portion is configured for fitting onto the distal anterior condylar osteotomy surface of the femur; The posterior portion is configured for fitting onto the distal posterior condylar osteotomy surface of the femur; A middle portion, configured to connect the front portion and the rear portion; and At least two through holes are configured to receive fasteners to secure the knee femoral prosthesis to the distal end of the femur. The at least two through holes include those whose hole-forming axes intersect each other or are not on the same plane.
2. The knee femoral prosthesis of claim 1, wherein, The knee joint femoral prosthesis is divided into an active zone configured to withstand friction and non-active zones located on both sides of the active zone, with at least two through holes disposed in the non-active zones.
3. The knee femoral prosthesis of claim 1, wherein, The fastening axis of the fastener received in the at least two through holes forms an angle with the hole-forming axis of the corresponding through hole.
4. The knee femoral prosthesis of claim 3, wherein, The included angle is 0° to 20°.
5. The knee femoral prosthesis of claim 2, wherein, At least one of the at least two through holes is provided with an internal thread.
6. The knee joint femoral prosthesis according to claim 1, characterized in that, The inner surfaces of the front, rear, and middle portions form a smooth inner surface of the knee joint femoral prosthesis along the direction of movement of the prosthesis, and at least one of them is curved.
7. The knee femoral prosthesis of claim 6, wherein, The curved surface and the adjacent inner surface are tangentially connected to each other.
8. The knee femoral prosthesis of claim 6, wherein, The surface has different curvatures along the direction of movement from the femoral prosthesis of the knee joint and at least one other direction intersecting the direction of movement.
9. The knee femoral prosthesis of claim 7, wherein, The surface in question is a sphere.
10. A knee prosthesis system, characterized by The knee joint prosthesis system includes: The knee femoral prosthesis according to any one of claims 1-9 is configured for fitting to the distal side of the femur of a patient. A tibial prosthesis for knee joint, the tibial prosthesis being configured for fitting onto the proximal side of the patient's tibia; and A spacer is disposed between the femoral prosthesis and the tibial prosthesis of the knee joint and is configured to have a first side and a second side opposite to each other, the first side being fixed to the tibial prosthesis of the knee joint and the second side being configured to mate with the femoral prosthesis of the knee joint.