Hollow conical head of hip joint femoral stem

Abstract

The utility model relates to the technical field of artificial hip joint prostheses, in particular to a hip joint femoral stem hollow conical head. Comprising a cone head surface (1), a cone side surface (2), a cone inner cavity (3) and a powder cleaning channel (5) which are connected in sequence, the conical head face (1) is used for sealing the in-conical cavity (3), the conical side face (2) is matched with a ceramic ball head or a metal ball head, the conical side face (2) is provided with a plurality of small protrusions (4) so that the femoral stem conical head can be matched with the ceramic ball head or the metal ball head more tightly, and the in-conical cavity (3) is used for increasing elastic deformation of the conical head. The small bulges (4) generate plastic deformation when the ceramic ball head or the metal ball head is assembled with the conical head, so that the contact area between the ball head and the conical head is increased, and the friction force is increased; and the powder cleaning channel (5) is used for cleaning unmelted powder in the cavity in additive manufacturing.

Description

Technical Field

[0001] This utility model relates to the field of artificial hip joint prosthesis technology, and in particular to a hollow cone-shaped femoral stem for hip joints. Background Technology

[0002] During hip replacement surgery, there is a risk of ceramic ball head breakage when assembling it with the femoral stem cone. Therefore, surgeons must be extremely careful during this procedure, but breakage cannot be completely avoided. The pull-out force after assembly of the ball head and femoral stem cone is also an important indicator for evaluating the quality of the assembly.

[0003] Currently, the main approach to reducing the breakage rate is to change the material and structure of the ceramic ball head. There are relatively few attempts to reduce the breakage rate of the ceramic ball head by changing the design of the cone.

[0004] Therefore, it is necessary to reduce the breakage rate of ceramic ball heads by hollowing out the femoral stem cone. Summary of the Invention

[0005] One objective of this invention is to provide a hollow femoral stem cone for hip joints that addresses the aforementioned shortcomings. This cone is highly elastic and lightweight, reducing the overall rigidity of the cone while meeting strength requirements, increasing the local elasticity of the cone, reducing the breakage rate of the ceramic ball head, and increasing the pull-out force after the ceramic ball head and the cone head are assembled.

[0006] To achieve the above objectives, the present invention provides a hollow conical head for the femoral stem of a hip joint, which is implemented using the following technical solution:

[0007] A hollow cone-shaped femoral stem for hip joints comprises a cone-shaped surface (1), a cone-shaped side surface (2), an inner cavity (3), and a powder cleaning channel (5) connected in sequence. The cone-shaped surface (1) is used to seal the inner cavity (3). The cone-shaped side surface (2) mates with a ceramic ball head or a metal ball head. The cone-shaped side surface (2) has several small protrusions (4) to make the femoral stem cone-shaped femoral stem and the ceramic ball head or the metal ball head fit more tightly. The inner cavity (3) is used to increase the elastic deformation of the cone-shaped femoral stem, making the cone-shaped femoral stem and the ceramic ball head or the metal ball head fit more tightly, while reducing the maximum principal stress during the assembly of the ceramic ball head, thus significantly reducing the breakage rate of the ceramic ball head. The small protrusions (4) generate plastic deformation during the assembly of the ceramic ball head or the metal ball head and the cone-shaped femoral stem, increasing the contact area between the ball head and the cone-shaped femoral stem and increasing the friction. The powder cleaning channel (5) is used to clean the unmelted powder in the hollow cavity during additive manufacturing.

[0008] The cone-shaped cavity (3) is provided with an upper cavity (3-1), a middle cavity (3-2), and a lower cavity (3-3), which are connected to each other. The lower cavity (3-3) is provided with a powder cleaning channel (5) at its lower part, which is connected to the cone-shaped cavity (3) and is used to clean the unmelted powder in the cavity during additive manufacturing.

[0009] The upper cavity (3-1) of a hollow femoral stem conical head of a hip joint has a conical surface (2) that contacts and fits with the inner conical hole of a metal / ceramic ball head. This is the main functional cavity, and its purpose is to reduce the overall rigidity of the conical head, increase the elastic deformation of the conical head, thereby increasing the contact area between the conical head and the ball head, reducing the contact stress of the ball head, significantly reducing the breakage rate of the ceramic ball head, and increasing the pull-out force after the conical head and the ball head are assembled. The middle cavity (3-2) is located below the upper cavity (3-1) and smoothly transitions to it. It can also be designed as the same cavity. This is a secondary functional cavity. In addition to trying to meet the functions described in the upper cavity (3-1), its main function is to accommodate the gradually increasing bending moment of the hollow femoral stem conical head starting from the upper conical surface. The increase in the section modulus of the section should not be less than the increase in the bending moment. The lower cavity (3-3) is located below the middle cavity (3-2) and smoothly transitions to it. Its main function is to guide the unmelted powder in the hollow cavity of the additive manufacturing process into the powder cleaning channel (5).

[0010] The conical side surface (2) has several small protrusions (4) with a height of 0.01-0.05 mm.

[0011] The hollow cone of the femoral stem of the hip joint is provided with a cavity containing a reinforcing structure, and the cavity contains a reinforcing structure and a supporting structure.

[0012] The hollow cone of the femoral stem of the hip joint is characterized in that the reinforcing structure can be set in the cavity of the femoral stem according to the requirements of strength and increased elastic deformation. The reinforcing structure is located in the cavity (3) of the cone along the part with poor mechanical properties. The cross section of the reinforcing structure is not limited to the reinforcing structure, but can be a ring reinforcing structure (6), a cross reinforcing structure (7), a single reinforcing structure (8), a porous reinforcing structure (9), etc.

[0013] The reinforcing structure can be installed in the upper cavity (3-1) and the middle cavity (3-2).

[0014] The reinforcing structure includes, depending on the mechanical performance requirements, a distribution in which no additional or at least one or more reinforcing structures are needed.

[0015] The hollow cone-shaped femoral stem of the hip joint is made of titanium alloy.

[0016] The hollow femoral stem cone of the hip joint is used as the cone of the femoral stem prosthesis. The femoral stem prosthesis and the cone are integrally formed using laser additive manufacturing technology and titanium alloy material.

[0017] The femoral stem prosthesis with a hollow conical head is made of titanium alloy.

[0018] The beneficial effects of this utility model of a hollow conical head for the femoral stem of the hip joint are as follows:

[0019] A hollow femoral stem cone for hip joints is reasonably designed. The use of a hollow femoral stem cone increases the elastic deformation of the cone, making the cone fit more tightly with the ceramic or metal ball head. At the same time, it reduces the maximum principal stress of the ceramic ball head, thus significantly reducing the breakage rate of the ceramic ball head.

[0020] A hollow cone head for the femoral stem of a hip joint adopts a hollow design, which can reduce weight and manufacturing costs.

[0021] Because the cone side (2) has several small protrusions (4) that make the femoral stem cone and the ceramic ball or metal ball fit more tightly, the cone cavity (3) is used to increase the elastic deformation of the cone, making the cone and the ceramic ball or metal ball fit more tightly, while reducing the maximum principal stress when assembling the ceramic ball, thus greatly reducing the breakage rate of the ceramic ball. The small protrusions (4) produce plastic deformation when the ceramic ball or metal ball and the cone are assembled, increasing the contact area between the ball and the cone and increasing the friction. Attached Figure Description

[0022] Figure 1 This is a coronal section view of the femoral stem where the hollow cone head of the femoral stem is located, provided in a specific embodiment of this utility model.

[0023] Figure 2 This is a cross-sectional view of the structure of a hollow cone-shaped femoral stem for hip joints provided in a specific embodiment of this utility model;

[0024] Figure 3 yes Figure 2 An enlarged view of a small protrusion 4 in a hollow cone-shaped femoral stem of a hip joint;

[0025] Figure 4 This is a schematic diagram of a ring-shaped reinforcing structure 6 for a hollow cone-shaped femoral stem of a hip joint;

[0026] Figure 5 This is a schematic diagram of a cross-shaped reinforcing structure 7 of a hollow cone-shaped femoral stem in a hip joint;

[0027] Figure 6 This is a schematic diagram of a single-line reinforcing structure 8 of a hollow cone-shaped femoral stem in a hip joint;

[0028] Figure 7This is a schematic diagram of a porous reinforced structure 9 of a hollow cone-shaped femoral stem in a hip joint.

[0029] In the picture:

[0030] 1. Conical head surface; 2. Conical side surface; 3. Conical internal cavity; 3-1. Upper cavity; 3-2. Middle cavity; 3-3. Lower cavity; 4. Fine thread; 5. Powder clearing channel; 6. Annular reinforcement structure; 7. Cross reinforcement structure; 8. Straight reinforcement structure; 9. Porous reinforcement structure; 10. Femoral stem prosthesis. Detailed Implementation

[0031] See attached document Figure 1-7 A hollow cone for the femoral stem of a hip joint includes a cone face (1), a cone side surface (2), an inner cavity (3), and a powder cleaning channel (5) connected in sequence. The cone face (1) is used to seal the inner cavity (3). The cone side surface (2) mates with a ceramic ball head or a metal ball head. The cone side surface (2) has several small protrusions (4) to make the femoral stem cone fit more tightly with the ceramic ball head or the metal ball head. The inner cavity (3) is used to increase the elastic deformation of the cone, making the cone fit more tightly with the ceramic ball head or the metal ball head, while reducing the maximum principal stress during the assembly of the ceramic ball head, thus significantly reducing the breakage rate of the ceramic ball head. The small protrusions (4) generate plastic deformation during the assembly of the ceramic ball head or the metal ball head and the cone, increasing the contact area between the ball head and the cone and increasing the friction. The powder cleaning channel (5) is used to clean the unmelted powder in the hollow cavity during additive manufacturing.

[0032] The cone-shaped cavity (3) is provided with an upper cavity (3-1), a middle cavity (3-2), and a lower cavity (3-3), which are connected to each other. The lower cavity (3-3) is provided with a powder cleaning channel (5) at its lower part, which is connected to the cone-shaped cavity (3) and is used to clean the unmelted powder in the cavity during additive manufacturing.

[0033] The upper cavity (3-1) of a hollow femoral stem cone of a hip joint has a conical side surface (2) that contacts and fits with the inner conical hole of the metal / ceramic ball head. This is the main functional cavity, which aims to reduce the overall rigidity of the cone head, increase the elastic deformation of the cone head, thereby increasing the contact area between the cone head and the ball head, reducing the contact stress of the ball head, significantly reducing the breakage rate of the ceramic ball head, and increasing the pull-out force after the cone head and the ball head are assembled. The middle cavity (3-2) is located below the upper cavity (3-1) and smoothly transitions with it. It can also be designed as the same cavity. This is a secondary functional cavity. In addition to trying to meet the functions described in the upper cavity (3-1), its main function is to adapt to the gradually increasing bending moment of the hollow femoral stem cone starting from the upper conical surface. The increase in the section modulus of the section should not be less than the increase in the bending moment. The lower cavity (3-3) is located below the middle cavity (3-2) and smoothly transitions to it. Its main function is to guide the unmelted powder in the hollow cavity of the additive manufacturing process into the powder cleaning channel (5).

[0034] The conical side surface (2) has several small protrusions (4) with a height of 0.01-0.05 mm.

[0035] The hollow cone of the femoral stem of the hip joint is provided with a cavity containing a reinforcing structure, and the cavity contains a reinforcing structure and a supporting structure.

[0036] The hollow cone of the femoral stem of the hip joint is characterized in that the reinforcing structure can be set in the cavity of the femoral stem according to the requirements of strength and increased elastic deformation. The reinforcing structure is located in the cavity (3) of the cone along the part with poor mechanical properties. The cross section of the reinforcing structure is not limited to the reinforcing structure.

[0037] The reinforcing structure is configured as a ring-shaped reinforcing structure (6), a cross-shaped reinforcing structure (7), a straight reinforcing structure (8), a porous reinforcing structure (9), etc.

[0038] The reinforcing structure can be installed in the upper cavity (3-1) and the middle cavity (3-2).

[0039] The reinforcing structure includes, depending on the mechanical performance requirements, a distribution in which no additional or at least one or more reinforcing structures are needed.

[0040] The hollow cone-shaped femoral stem of the hip joint is made of titanium alloy.

[0041] The hollow femoral stem cone of the hip joint is used as the cone of the femoral stem prosthesis. The femoral stem prosthesis and the cone are integrally formed using laser additive manufacturing technology and titanium alloy material.

[0042] The femoral stem prosthesis with a hollow conical head is made of titanium alloy.

Claims

1. A hip femoral stem cannulated taper, characterized in that, It comprises a cone head surface (1), a cone side surface (2), a cone inner cavity (3) and a powder cleaning channel (5) connected in sequence; the cone head surface (1) is used for closing the cone inner cavity (3), the cone side surface (2) is matched with a ceramic ball head or a metal ball head, the cone side surface (2) has a plurality of small protrusions (4) to make the femoral stem cone head and the ceramic ball head or the metal ball head match more closely, the cone inner cavity (3) is used for increasing the elastic deformation of the cone head, the small protrusions (4) are plastically deformed when the ceramic ball head or the metal ball head is assembled with the cone head, the contact area of the ball head and the cone head is increased, and the friction force is increased; the powder cleaning channel (5) is used for cleaning the unfused powder in the cavity in additive manufacturing.

2. A hip stem cannulated taper according to claim 1, wherein, The cone inner cavity (3) is provided with an upper cavity (3-1), a middle cavity (3-2) and a lower cavity (3-3), the upper cavity (3-1), the middle cavity (3-2) and the lower cavity (3-3) are in communication with each other, the lower part of the lower cavity (3-3) is provided with a powder cleaning channel (5), the powder cleaning channel (5) is in communication with the cone inner cavity (3), and the powder cleaning channel (5) is used for cleaning the unfused powder in the cavity in additive manufacturing.

3. A hip stem cannulated taper according to claim 2, wherein, The cone side surface (2) of the upper cavity (3-1) of the femoral stem hollow cone head is in contact with the inner cone hole of the metal / ceramic ball head, the overall rigidity of the cone head is reduced, the elastic deformation of the cone head is increased, the contact area of the cone head and the ball head is increased, and the contact stress of the ball head is reduced.

4. A hip stem cannulated taper according to claim 2, wherein, The middle cavity (3-2) is located below the upper cavity (3-1) and is smoothly transitioned therewith; the lower cavity (3-3) is located below the middle cavity (3-2) and is smoothly transitioned therewith, and the action is to guide the unfused powder in the cavity in additive manufacturing into the powder cleaning channel (5).

5. The hip stem cannulated taper according to claim 1, wherein, The cone side surface (2) has a plurality of small protrusions (4) with a height of 0.01-0.05mm.

6. A hip stem cannulated taper according to claim 1, wherein, The femoral stem hollow cone head is provided with a cavity of a reinforcing structure, and the cavity of the reinforcing structure is provided with a reinforcing structure and a supporting structure.

7. A hip stem cannulated taper according to claim 6, wherein, The reinforcing structure can be arranged in the upper cavity (3-1) and the middle cavity (3-2).

8. A hip stem cannulated taper according to claim 6, wherein, The reinforcing structure is arranged in the form of a ring reinforcing structure (6), a cross reinforcing structure (7), a straight-line reinforcing structure (8) or a porous reinforcing structure (9).

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