Femoral stem prosthesis

Abstract

The invention provides a femoral stem prosthesis, and belongs to the technical field of medical instruments. The femoral stem prosthesis comprises a femoral neck and a stem body; the stem body is provided with a stem body and a stem neck which are connected, and one end of the stem neck deviating from the stem body is connected with the femoral neck; a plurality of notches are formed in the side, away from the femoral neck, of the stem neck in the first direction, are arranged at intervals in the second direction and penetrate through the stem neck in the third direction. According to the femoral stem prosthesis, due to the fact that the notches are formed, when the stem neck in the stem body is bent inwards, the side, away from the femoral neck, of the stem neck rotates clockwise with the ends, close to the femoral neck in the first direction, of the notches as midpoints along the side, away from the femoral neck in the first direction, of the stem neck under the action of physiological loads in the second direction; a larger load is transmitted to the side, deviating from the femoral neck in the first direction, of the stem neck through the stem neck, so that bone resorption caused by stress shielding of the sides, deviating from the notch, of the stem neck and the stem body is avoided.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a femoral stem prosthesis. Background Technology

[0002] Total hip arthroplasty (THA) is the gold standard for treating end-stage hip disease. However, aseptic loosening of the femoral stem due to stress shielding is a major mechanical factor leading to THA failure. When a metallic femoral stem is implanted, the stress state of the femur is redistributed, with the more rigid metallic stem bearing a greater load, resulting in reduced stress on the surrounding bone tissue. This "shielding" effect triggers bone remodeling and resorption under low stress levels, ultimately leading to failure of the femoral stem-bone fixation interface.

[0003] Currently, clinically used femoral stems primarily minimize stress shielding by shortening the stem length, employing a collar structure, and designing a tapered stem body. These designs have shown some effectiveness in improving stress shielding near the lesser trochanter of the femur. However, according to clinical and biomechanical studies, these designs have limited effectiveness in improving stress shielding near the greater trochanter of the femur. The fundamental reason is that the femoral stem tends to bend medially under load in vivo, resulting in relatively insufficient load transmission to the proximal lateral femur (i.e., the opposite side of the bending direction). Therefore, even with geometric optimization, the stress level in the proximal lateral femoral region remains difficult to restore effectively, and the stress shielding problem persists.

[0004] In recent years, the use of 3D printing technology to fabricate porous femoral stems has been shown to have the potential to reduce stress shielding. However, the porous structure itself, as well as the unavoidable micropore defects during additive manufacturing, can become initiation points for fatigue cracks, resulting in lower fatigue resistance compared to femoral stems based on traditional forgings or castings. Therefore, despite the potential advantages of 3D-printed porous femoral stems in improving stress shielding, their large-scale clinical application remains limited. Summary of the Invention

[0005] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and provide a femoral stem prosthesis.

[0006] This application provides the following technical solution: a femoral stem prosthesis having mutually perpendicular first, second, and third directions, including: femoral neck; The handle has a handle body and a handle neck connected together, and the end of the handle neck opposite to the handle body is connected to the femoral neck; The stem neck has multiple notches on the side opposite to the femoral neck along the first direction, the multiple notches are spaced apart along the second direction, and the notches penetrate the stem neck along the third direction.

[0007] In some embodiments of this application, the notch has a first wall surface and a second wall surface disposed opposite to each other along the second direction, the first wall surface being parallel to the second wall surface, and the distance between the first wall surface and the second wall surface being W; The value of W is in the range of 0.2mm ≤ W ≤ 1mm.

[0008] In some embodiments of this application, the angle between the first wall surface and the axis of the handle is α, and the axis of the handle is parallel to the first direction, wherein the value of α is in the range of 30°≤α≤80°.

[0009] In some embodiments of this application, the length of the notch is L, wherein the value of L is in the range of 6mm≤L≤20mm.

[0010] In some embodiments of this application, the length of each of the notches is equal.

[0011] In some embodiments of this application, the plurality of said notches are arranged at equal intervals along the second direction.

[0012] In some embodiments of this application, the first wall and the second wall are respectively parallel to the third direction.

[0013] In some embodiments of this application, the notch has a third wall surface facing the femoral neck along the first direction, the third wall surface being recessed into the femoral neck along the first direction to form an arc surface.

[0014] In some embodiments of this application, the distance from the end of the third wall near the first wall to the end of the third wall away from the first wall is equal to the distance W between the first wall and the second wall.

[0015] In some embodiments of this application, the stem neck is tilted relative to the stem body along the first direction toward the side closer to the femoral neck.

[0016] The embodiments of this application have the following advantages: By providing multiple notches on the side of the stem neck away from the femoral neck along a first direction, when the femoral stem prosthesis is subjected to a physiological load along a second direction from the femoral neck towards the stem body, the stem neck in the stem body bends inward. This causes the side of the stem neck away from the femoral neck to rotate clockwise along the first direction away from the femoral neck under the physiological load in the second direction, with the notch near the femoral neck as the midpoint. This allows for the transmission of a larger load through the stem neck to the side of the stem neck away from the femoral neck along the first direction, thereby preventing bone resorption on the side of the stem neck and stem body away from the notches due to stress shielding. This not only preserves the complete outline of the femoral stem but also reduces the stiffness of the stem neck, increasing the tendency of the femoral stem prosthesis to bend inward, thereby increasing the load transmitted to the proximal medial femur and reducing the risk of bone resorption in the medial femur due to stress shielding. At the same time, the notch design ensures the filling rate of the femoral medullary cavity by the femoral stem, which is beneficial for maintaining the initial stability of the prosthesis.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This application provides a schematic diagram of the structure of a femoral stem prosthesis from one perspective, based on some embodiments thereof. Figure 2 This application provides a schematic diagram of the structure of a femoral stem prosthesis from another perspective, illustrating some embodiments thereof. Figure 3 This application provides a schematic diagram illustrating the bending direction of a femoral stem prosthesis stem under stress, according to some embodiments of the present application. Figure 4 A schematic diagram of the finite element analysis process of the femoral stem prosthesis of the present invention, wherein (a) is a conventional solid metal femoral stem, (b) is the femoral stem prosthesis of the present invention, (c) is the simulated implantation of the femoral stem prosthesis, (d) is the mesh generation and material property setting of the femur and femoral stem, and (e) is the load and boundary condition setting. Figure 5Von-Mises stress distribution cloud map of the femur under physiological load provided by the present invention, (a) implanted solid femur and (b) implanted femoral stem prosthesis provided by the present invention; Figure 6 This is a comparison chart of stress values ​​between a conventional solid femoral stem in existing femoral implantation technology and the femoral stem prosthesis implanted with the present invention.

[0020] Explanation of key component symbols: 100 - Femoral neck; 200 - Handle body; 210 - Handle shaft; 220 - Handle neck; 221 - Notch; 222 - First wall surface; 223 - Second wall surface; 224 - Third wall surface; 300 - Ball head connection.

[0021] X - First direction; Z - Second direction; Y - Third direction. Detailed Implementation

[0022] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0023] It should be noted that when an element is said to be "fixed" to another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly" on another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the template description is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] like Figures 1 to 3 As shown, this application provides a femoral stem prosthesis having a first direction X, a second direction Z and a third direction Y that are perpendicular to each other. It is mainly used to reduce stress shielding on the medial and lateral sides of the proximal femur, avoid bone resorption in the proximal femur, and improve the problem of aseptic loosening of the femoral stem caused by stress shielding after total hip arthroplasty.

[0028] The femoral stem prosthesis includes a femoral neck 100 and a stem body 200. In this embodiment, the femoral neck 100 and the stem body 200 are integrally molded to form the femoral stem prosthesis, so as to improve the overall strength and stability of the femoral stem prosthesis.

[0029] The handle 200 has a handle body 210 and a handle neck 220 connected to each other. The end of the handle neck 220 away from the handle body 210 is connected to the femoral neck 100. It should be noted that the handle neck 220 is inclined relative to the handle body 210 in the first direction X towards the side closer to the femoral neck 100.

[0030] In this embodiment, the neck 220 and the body 210 are integrally formed to ensure the overall strength and stability of the body 200. The axis of the body 210 is parallel to the second direction Z.

[0031] In addition, the stem neck 220 is provided with a plurality of notches 221 on the side opposite to the femoral neck 100 along the first direction X. It can be understood that the number of notches 221 can be any number of two or more values, and can be specifically set according to the actual situation.

[0032] In this embodiment, the plurality of notches 221 are arranged at intervals along the second direction Z. In some embodiments, the plurality of notches 221 are arranged at equal intervals along the second direction Z; in other embodiments, the spacing between the plurality of notches 221 along the second direction Z gradually increases; and in still other embodiments, the spacing between the plurality of notches 221 along the second direction Z gradually decreases.

[0033] Wherein, the notch 221 penetrates the stem neck 220 along the third direction Y, and the notch 221 penetrates the stem neck 220 on the side away from the femoral neck 100 along the first direction X, thereby forming a plurality of notches 221 at the end of the stem neck 220 away from the femoral neck 100 along the first direction X.

[0034] It should be noted that the inventors discovered that when an overly rigid femoral stem prosthesis is implanted in the human body, most of the mechanical load that would normally be borne by the proximal medial femoral bone is blocked by this rigid prosthesis. Because the bone loses its normal mechanical stimulation, it initiates the "use it or lose it" mechanism, resulting in atrophy and resorption, leading to thinning of the bone and loss of bone mass.

[0035] Based on this, this application provides multiple notches 221 on the side of the stem neck 220 away from the femoral neck 100 along the first direction X. When the femoral stem prosthesis is subjected to a physiological load along the second direction Z from the femoral neck 100 toward the stem body 200 in the body, the stem neck 220 in the stem body 200 bends inward. Under the action of the physiological load in the second direction Z, the side of the stem neck 220 away from the femoral neck 100 rotates clockwise along the first direction X away from the femoral neck 100 with the notch 221 near the end of the first direction X close to the femoral neck 100 as the midpoint. Thus, a larger load is transmitted through the stem neck 220 to the side of the stem neck 220 away from the femoral neck 100 along the first direction X, thereby avoiding bone resorption on the side of the stem neck 220 and the stem body 210 away from the notch 221 due to stress shielding.

[0036] The femoral stem prosthesis provided in this application, by providing a notch 221 on the neck 220 in the stem body 200, not only retains the complete outline of the femoral stem but also reduces the stiffness of the neck 220, increasing the tendency of the femoral stem prosthesis to bend medially. This increases the load transmitted to the proximal medial femur and reduces the risk of bone resorption in the medial femur due to stress shielding. At the same time, the design of the notch 221 ensures the filling rate of the femoral stem into the femoral medullary cavity, which is beneficial to maintaining the initial stability of the prosthesis.

[0037] like Figure 1As shown, in some embodiments of this application, the notch 221 has a first wall surface 222 and a second wall surface 223 disposed opposite to each other along the second direction Z. The first wall surface 222 is parallel to the second wall surface 223. The first wall surface 222 and the second wall surface 223 are respectively parallel to the third direction Y. The distance between the first wall surface 222 and the second wall surface 223 is W.

[0038] The value of W is in the range of 0.2mm ≤ W ≤ 1mm.

[0039] It is understandable that the value of W can be one of the following: 0.2mm≤W≤1mm, 0.3mm≤W≤1mm, 0.4mm≤W≤1mm, 0.5mm≤W≤1mm, 0.6mm≤W≤1mm, 0.7mm≤W≤1mm, 0.8mm≤W≤1mm, and 0.9mm≤W≤1mm.

[0040] like Figure 1 As shown, in some embodiments of this application, the angle between the first wall surface 222 and the axis of the handle 210 is α. It can be understood that the angle between the second wall surface 223 and the axis of the handle 210 is also α. The axis of the handle 210 is parallel to the first direction X. The value of α is 30°≤α≤80°.

[0041] It is understandable that the value of α can be one of the following: 30°≤α≤80°, 35°≤α≤80°, 40°≤α≤80°, 45°≤α≤80°, 50°≤α≤80°, 55°≤α≤80°, 60°≤α≤80°, 65°≤α≤80°, 70°≤α≤80°, and 75°≤α≤80°.

[0042] like Figure 1 As shown, in some embodiments of this application, the length of the notch 221 is L, wherein the value of L is in the range of 6mm≤L≤20mm.

[0043] It is understandable that the value of L can be one of the following: 6mm≤L≤20mm, 7mm≤L≤20mm, 8mm≤L≤20mm, 9mm≤L≤20mm, 10mm≤L≤20mm, 11mm≤L≤20mm, 12mm≤L≤20mm, 13mm≤L≤20mm, 14mm≤L≤20mm, 6mm≤L≤20mm, 15mm≤L≤20mm, 16mm≤L≤20mm, 17mm≤L≤20mm, 18mm≤L≤20mm, and 19mm≤L≤20mm.

[0044] It should be noted that the length L of the notch 221 refers to the distance from the end of the first wall 222 away from the femoral neck 100 to the end near the femoral neck 100 along the direction parallel to the first wall 222; or the distance from the end of the second wall 223 away from the femoral neck 100 to the end near the femoral neck 100 along the direction parallel to the second wall 223.

[0045] It is worth noting that the filling rate of the femoral stem into the femoral medullary cavity is one of the key factors affecting the success or failure of the surgery and its long-term effects.

[0046] Based on this, in this embodiment, the length, width, and number of notches 221 are controlled to ensure the filling rate of the femoral stem to the femoral medullary cavity.

[0047] It should be noted that by controlling the filling rate of the femoral stem into the femoral medullary cavity, the contact area between the femoral stem prosthesis and the patient's bone can be guaranteed, allowing the femoral stem prosthesis to fit tightly into the patient's bone. This effectively resists rotational, subsidence, and varus / valgus stresses, providing a stable mechanical environment for the bone ingrowth of the femoral stem prosthesis.

[0048] In addition, by ensuring close contact between the femoral stem prosthesis and the patient's bone, the load (stress) can be transferred to the bone more evenly and directly, avoiding localized stress concentration. Furthermore, it can reduce harmful micromovements at the femoral stem prosthesis-bone interface postoperatively; micromovements are a major cause of fibrous membrane formation (rather than bone ingrowth) and loosening.

[0049] The inventors discovered that if the notches 221 on the femoral stem are of unequal length, the longer (weaker) notches 221 will deform more first, bear most of the stress, and are very likely to become the starting point of fatigue failure, while the shorter notches 221 are "idle" and the material is not effectively utilized.

[0050] Based on this, such as Figure 2 and Figure 3 As shown, in some embodiments of this application, the length of each notch 221 is equal to ensure that when the stem neck 220 is subjected to a physiological load along the second direction Z from the femoral neck 100 toward the stem body 200, the bending deformation of the stem neck 220 and the resulting stress are evenly distributed to each notch 221, and no single notch 221 will bear stress far exceeding that of other notches 221, thereby avoiding excessive local stress.

[0051] Secondly, the equal-length notch 221 ensures that the entire neck 220 has no obvious "weakest link". Since the stress state of each notch 221 is consistent, the inventors can reliably estimate the life of the entire connecting block under cyclic load based on the fatigue test data of a single notch 221, thereby eliminating the "short board effect" and minimizing the risk of fatigue fracture of the neck 220.

[0052] In addition, since each notch 221 has the same length, it is only necessary to optimize the geometry (length, width, and fillet radius) of one notch 221 element and then perform array replication, which greatly simplifies finite element analysis and mechanical calculations and improves the accuracy of analysis and calculation.

[0053] like Figures 1 to 3 As shown, in some embodiments of this application, multiple notches 221 are arranged at equal intervals along the second direction Z to form a controllable, distributed flexible hinge structure on the side of the stem 220 opposite to the femoral neck 100. This allows multiple notches 221 to deform collaboratively during bending of the stem 220 under external force, resulting in a smooth, continuous, and uniform curvature of the entire connecting block, rather than a sharp, destructive bend at a single location. Secondly, the equal spacing ensures that the deformation and stress level borne by each notch 221 are essentially consistent. This means that no single notch 221 will "overwork," avoiding premature fracture caused by excessive local stress. This creates a "flexible zone" in the femoral stem prosthesis, allowing beneficial, minute elastic deformation between the patient's bone and the femoral stem prosthesis, mimicking the cushioning function of natural bone and improving comfort. It is worth noting that appropriate micro-movements can stimulate bone growth, helping the femoral stem prosthesis to grow more firmly.

[0054] like Figure 1 As shown, in some embodiments of this application, the notch 221 has a third wall surface 224 facing the femoral neck 100 along the first direction X. The third wall surface 224 is recessed towards the femoral neck 100 along the first direction X to form an arc surface, so as to reduce the stress concentration and prosthesis failure caused by stress concentration during the bending process of the stem neck 220 under the action of external force.

[0055] In this embodiment, the distance from the end of the third wall surface 224 closest to the first wall surface 222 to the end of the third wall surface 224 furthest from the first wall surface 222 is equal to the distance W between the first wall surface 222 and the second wall surface 223. That is, the diameter of the third wall surface 224 is equal to the width of the notch 221, ensuring that the flexibility (weakest section) at each notch 221 is the same. Under external force, bending deformation is evenly distributed across each notch 221, rather than concentrated on one or a few notches 221. This avoids premature fatigue or fracture caused by excessive local stress.

[0056] Understandably, the third wall surface 224 is smoothly connected to the first wall surface 222 and the second wall surface 223 respectively, so that the handle 200 can produce a smooth and continuous bending arc during the bending process, rather than a sharp bend at a certain point.

[0057] This application achieves a smooth and gradual change in the effective load-bearing cross-section of the notch 221 throughout the bending process by making the width of the notch 221 equal to the diameter corresponding to the third wall surface 224. This fundamentally eliminates sharp stress concentration points, distributing stress over a wider area, thereby significantly improving the fatigue life and reliability of the handle 200.

[0058] like Figures 1 to 3 As shown, in some embodiments of this application, the femoral neck 100 is provided with a ball head connecting portion 300 at one end away from the stem body 200, and the ball head connecting portion 300 is used to connect with the femoral head ball head.

[0059] In some embodiments of this application, the femoral stem prosthesis is made of solid, dense metal and can be manufactured by 3D printing or profile machining.

[0060] In addition, the materials for the femoral stem prosthesis can be zirconium-niobium alloy, titanium alloy, or cobalt-chromium-molybdenum alloy.

[0061] The following test data are provided to illustrate the performance of the femoral stem prosthesis of the present invention.

[0062] 1. Method The finite element analysis of the stress shielding improvement effect of the femoral stem prosthesis of this invention was conducted. This experiment was based on CT scan data of a healthy male lower limb, and a three-dimensional model of the right femur was reconstructed. According to actual clinical procedures, the femoral head was simulated for resection, and the implantation position of the femoral stem was determined by referring to the anatomical structure of the femur, thus completing the simulated implantation of the femoral stem prosthesis (e.g., Figure 4 (as shown in (c)). In this experiment, the key dimensions of the femoral stem prosthesis provided by this invention are set as follows: the length L of notch 221 is 14 mm, the width W of notch 221 is 1 mm, and the angle between notch 221 and the long axis of the femoral stem is 65°. To study the improvement effect of the femoral stem prosthesis provided by this invention on stress shielding, this study also set up two control groups: a normal femur (unoperated femur) and a conventional solid femoral stem with the same outline as the femoral stem prosthesis provided by this invention. The solid femoral stem and the femoral stem proposed in this invention have the following shapes: Figure 4 As shown in (a) and (b) in the figure.

[0063] The femur and femoral stem prosthesis were meshed using first-order tetrahedral elements with an element side length of 2 mm (e.g., Figure 4(as shown in (d)). The material parameters of the femur were assigned based on the grayscale values ​​of the femur CT images. There is a linear relationship between grayscale values ​​and bone tissue density. Following the method of Charalampos et al., the density corresponding to the highest grayscale value (1835 HU in this study) was set to 1.75 g / cm³, and the grayscale value of low-density cancellous bone in the greater trochanter region was 100 HU, with a density set to 0.05 g / cm³. The linear relationship formula was determined by two points to obtain the relationship between density and grayscale value. Then, the formula between elastic modulus (E) and density (ρ) was used (E=3790ρ). 3 ), complete the setting of the femoral elastic modulus (e.g. Figure 4 (As shown in (d)). The Poisson's ratio of the femur is 0.3. The elastic modulus of the prosthesis is 110 GPa, and the Poisson's ratio is 0.3. Assume that all materials are homogeneous and isotropic.

[0064] The contact properties between the femoral stem prosthesis and the femur were set as frictional contact with a friction coefficient of 0.1. The simulation employed a finite deformation static analysis method, simulating the femoral biomechanical response after joint replacement based on the ultimate load state of the hip joint during the human gait cycle. The load was set to 1600 N (approximately twice the patient's body weight), with the loading position located at the center of the femoral stem cone and the loading direction perpendicularly downwards (e.g., ...). Figure 4 (As shown in (e)). Furthermore, the distal femur was restrained and fixed during load application (e.g., Figure 4 (As shown in (e)). Finally, the stress distribution of the femur after implantation of the solid femoral stem and the femoral stem prosthesis provided by the present invention was observed and recorded, and compared to evaluate the effect of the tensile structure femoral stem prosthesis on stress shielding.

[0065] 2. Results Von-Mises stress cloud diagrams of conventional solid femoral stems and the tensile structure femoral stems of this invention are shown below. Figure 5 As shown. The Von-Mises stress of all elements located in each Gruen region of the femur was extracted, and its average value was calculated (e.g., ...). Figure 6 As shown). According to the formula ( The improvement of stress shielding by the femoral stem provided by this invention compared to a solid femoral stem is quantified. Positive values ​​indicate an improvement in stress shielding (as shown in Table 1).

[0066] The results showed that, compared with conventional solid femoral stems, the implantation of the femoral stem provided by this invention resulted in greater Von-Mises stress values ​​in each Grue zone of the femur, especially in the proximal medial (zone 1) and proximal lateral (zone 7) regions, where stress shielding was significantly improved. Specifically, stress shielding in the proximal medial (zone 1) and proximal lateral (zone 7) regions was improved by 72.81% and 41.81%, respectively.

[0067] Table 1. Average Von-Mises stress in each Gruen region of the femur after surgery and the improvement rate of stress shielding of the present invention compared with conventional solid rod.

[0068] 3. Conclusion The femoral stem prosthesis provided by this invention can transmit a greater load to the surrounding bone under physiological load compared to conventional solid stems, thereby effectively avoiding bone resorption caused by stress shielding after total hip arthroplasty and reducing the risk of prosthesis loosening.

[0069] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0070] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0071] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A femoral stem prosthesis having mutually perpendicular first, second, and third directions, characterized in that, include: femoral neck; The handle has a handle body and a handle neck connected together, and the end of the handle neck opposite to the handle body is connected to the femoral neck; The stem neck has multiple notches on the side opposite to the femoral neck along the first direction, the multiple notches are spaced apart along the second direction, and the notches penetrate the stem neck along the third direction.

2. The femoral stem prosthesis according to claim 1, characterized in that, The notch has a first wall and a second wall disposed opposite to each other along the second direction, the first wall being parallel to the second wall, and the distance between the first wall and the second wall being W; The value of W is in the range of 0.2mm ≤ W ≤ 1mm.

3. The femoral stem prosthesis according to claim 2, characterized in that, The angle between the first wall surface and the axis of the handle is α, and the axis of the handle is parallel to the first direction, wherein the value of α is in the range of 30°≤α≤80°.

4. The femoral stem prosthesis according to claim 1, characterized in that, The length of the notch is L, where the value of L is in the range of 6mm ≤ L ≤ 20mm.

5. The femoral stem prosthesis according to any one of claims 1 to 4, characterized in that, Each of the aforementioned gaps is of equal length.

6. The femoral stem prosthesis according to any one of claims 1 to 4, characterized in that, The plurality of the notches are arranged at equal intervals along the second direction.

7. The femoral stem prosthesis according to claim 2, characterized in that, The first wall and the second wall are respectively parallel to the third direction.

8. The femoral stem prosthesis according to claim 7, characterized in that, The notch has a third wall surface facing the femoral neck along the first direction, and the third wall surface is recessed into the femoral neck along the first direction to form an arc surface.

9. The femoral stem prosthesis according to claim 8, characterized in that, The distance from the end of the third wall closest to the first wall to the end of the third wall furthest from the first wall is equal to the distance W between the first wall and the second wall.

10. The femoral stem prosthesis according to claim 1, characterized in that, The stem neck is tilted relative to the stem body along the first direction toward the side closer to the femoral neck.

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