A combined femoral stem prosthesis

Abstract

The present application relates to a femoral stem prosthesis, in particular to a modular femoral stem prosthesis. The key points of its technical solution are as follows: It includes a proximal body, a narrow part body, and a distal body arranged in sequence. On the side of the proximal body facing away from the narrow part body, there is a neck part, and a stem taper is formed on the neck part; the neck part, the proximal body, the narrow part body, and the distal body are detachably fixed together; the purpose of improving the applicability of the femoral stem prosthesis to different patients and reducing the upfront design and processing costs of the femoral stem prosthesis is achieved.

Description

Technical Field

[0001] The present application relates to a femoral stem prosthesis, and in particular to a combined femoral stem prosthesis. Background Art

[0002] A femoral stem prosthesis is a surgical implant that replaces the femoral part of the human hip joint. It is used in hemihip replacement surgery and is used in combination with a ball head and a total acetabulum.

[0003] The femoral stem prosthesis recorded in the relevant technology is usually an integrated structure. Before the operation, the femoral stem prosthesis needs to be customized or designed with the corresponding size and shape according to the patient's body structure to achieve customized and serialized adaptability of the femoral stem prosthesis to the body structures of different patients. However, the problem is that due to the diversity of the femoral medullary cavity morphology of patients, the customized and serialized femoral stem prosthesis leads to a small product coverage population. A single femoral stem prosthesis can only meet the needs of patients with a certain femoral medullary cavity morphology, which increases the initial design and processing costs of the femoral stem prosthesis to a certain extent. Summary of the invention

[0004] In order to improve the applicability of a femoral stem prosthesis to different patients and to reduce the initial design and processing costs of the femoral stem prosthesis, the present application provides a combined femoral stem prosthesis.

[0005] The combined femoral stem prosthesis provided in this application adopts the following technical solution:

[0006] A combined femoral stem prosthesis comprises a proximal body, a narrow body and a distal body which are arranged in sequence. A neck is arranged on the side of the proximal body away from the narrow body, and a stem cone is formed on the neck. The neck, the proximal body, the narrow body and the distal body are detachably fixed.

[0007] By adopting the above technical scheme, the femoral stem prosthesis is divided into four mutually detachable parts, the neck and the stem cone are used to install the ball head and the total acetabulum, and the proximal body, the narrow body or the distal body of corresponding size and structure are selected according to the patient's medullary cavity structure before the operation, and then the three are assembled to assemble a femoral stem prosthesis that is more compatible with the patient's medullary cavity structure; compared with custom-making the entire femoral stem prosthesis according to the patient's medullary cavity structure and size before the operation, the present application improves the applicability of the femoral stem prosthesis to different patients, so as to reduce the initial design and processing costs of the femoral stem prosthesis.

[0008] Optionally, a connecting rod is formed on the distal body and passes through the narrow body and the proximal body in sequence, the end face of the distal body abuts against the end face of the narrow body, the connecting rod extends to the inside of the neck, and a fixing screw screwed on the end face of the connecting rod is arranged inside the neck.

[0009] By adopting the above technical solution, the distal body and the neck tend to approach each other during the process of screwing the fixing screw, and the narrow body and the proximal body are then compressed and fixed between the distal body and the neck.

[0010] Optionally, a plug-in hole matching the end of the connecting rod is opened on the surface of the neck near the proximal body, the end of the connecting rod away from the distal body has a taper, and the diameter of the tapered part of the connecting rod gradually decreases along the direction from close to to away from the distal body.

[0011] By adopting the above technical solution, an effective and reliable taper fit is formed between the connecting rod and the neck. When the neck is subjected to pressure from human bones or tissues, the fit between the neck and the connecting rod is more reliable, thereby improving the assembly stability of the entire femoral stem prosthesis.

[0012] Optionally, one end of the distal body facing away from the narrow portion body has a taper, and the diameter of the tapered portion of the distal body gradually decreases along a direction from approaching to away from the narrow portion body.

[0013] By adopting the above technical solution, when inserting the femoral stem prosthesis, since the distal body has a taper, it is easier for the distal body to pass through the osteotomy surface into the medullary cavity and penetrate deeper into the medullary cavity.

[0014] Optionally, a plurality of deformation grooves are provided on the peripheral wall of the distal body, which allow the distal body to deform in a direction close to its own axis, and the deformation grooves are distributed at intervals along the circumference of the distal body.

[0015] By adopting the above technical solution, when the femoral stem prosthesis is to be inserted into the medullary cavity, the peripheral wall of the distal body is pressed to deform toward its own axis, thereby facilitating the distal body to pass through the osteotomy surface and enter the medullary cavity.

[0016] Optionally, the diameter of the narrow portion body gradually increases along the direction from the distal body to the proximal body.

[0017] By adopting the above technical solution, the narrow part body corresponds to the narrowest part of the medullary cavity, and the narrow part body has a taper so that it can better adapt to this part of the medullary cavity, thereby improving the postoperative stability of the prosthesis body.

[0018] Optionally, the handle cone is inclined toward one side of the proximal body along a direction from approaching to moving away from the proximal body, and a bionic protrusion is formed on one side of the proximal body, and the bionic protrusion protrudes in a direction away from the handle cone.

[0019] By adopting the above technical solution, the bionic protrusion is adapted to the shape of the wall of the proximal femoral medullary cavity, and the wall of the medullary cavity can further improve the overall stability of the prosthesis body by supporting the bionic protrusion.

[0020] Optionally, the proximal body includes two oppositely arranged first mating surfaces, and the bionic protrusions are formed on the first mating surfaces facing away from the shank taper; the distance between the two first mating surfaces gradually increases along the direction from near to far from the narrow body.

[0021] By adopting the above technical solution, the two sides of the proximal body are better adapted to the internal shape of the tapered medullary cavity. When the femoral stem prosthesis is under the pressure of the human bone or tissue, a press fit is formed between the first mating surface and the medullary cavity wall, which promotes the bone ingrowth effect of the first mating surface.

[0022] Optionally, the proximal body further includes two oppositely arranged second mating surfaces, and the distance between the planes where the two second mating surfaces are located gradually increases along the direction from near to far from the narrow body; there is an included angle between the sides of the two second mating surfaces close to the shank taper, and the distance between the two sides gradually decreases along the direction from near to far from the bionic protrusion.

[0023] By adopting the above technical solution, the other two sides of the proximal body are better adapted to the internal shape of the tapered medullary cavity. When the femoral stem prosthesis is under the pressure of the human bone or tissue, a press fit is formed between the second mating surface and the medullary cavity wall, which promotes the bone ingrowth effect of the second mating surface.

[0024] Optionally, part or all of the proximal body, the narrow body, and the distal body are 3D printed trabecular bone structures.

[0025] By adopting the above technical solution, the proximal body, the narrow body, and the distal body have trabecular bone structures with good bone ingrowth effects on their surfaces, so that the femoral stem prosthesis can obtain good postoperative stability after being inserted into the medullary cavity.

[0026] In summary, the present application has the following technical effects:

[0027] 1. By providing a neck portion, a proximal body, a narrow body, and a distal body that are detachably connected to each other, compared with customizing and processing the entire femoral stem prosthesis according to the patient's medullary cavity structure and size before surgery, the present application improves the applicability of the femoral stem prosthesis to different patients, reduces the upfront design and processing costs of the femoral stem prosthesis, and also simplifies the subsequent femoral stem prosthesis revision operation;

[0028] 2. By providing a distal body that can generate elastic deformation, it is convenient for the distal body to pass through the osteotomy surface and enter the medullary cavity. In addition, after the distal body is inserted into the medullary cavity, by making the distal body generate elastic deformation so that the medullary cavity wall exerts a certain pressure on the peripheral surface of the distal body, the distal body then deforms to better adapt to the shape of the medullary cavity and improve the postoperative stability of the femoral stem prosthesis in the medullary cavity;

[0029] 3. By making the proximal body have a certain taper, the proximal body can better adapt to the tapered internal shape of the medullary cavity. When the femoral stem prosthesis is subjected to pressure from human bones or tissues, a pressure fit is formed between the surface of the proximal body and the wall of the medullary cavity, thereby promoting the bone ingrowth effect on the surface of the proximal body. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the overall structure of the femoral stem prosthesis in an embodiment of the present application;

[0031] Figure 2 is a cross-sectional view of a femoral stem prosthesis in an embodiment of the present application;

[0032] Figure 3 is a side view of a femoral stem prosthesis in an embodiment of the present application;

[0033] Figure 4 It is a top view of the femoral stem prosthesis in an embodiment of the present application.

[0034] In the figure, 1, proximal body; 11, first mating surface; 12, second mating surface; 2, narrow body; 3, distal body; 31, deformation groove; 4, neck; 41, insertion hole; 5, handle cone; 6, connecting rod; 7, fixing screw; 8, bionic protrusion. DETAILED DESCRIPTION

[0035] The present application is further described in detail below in conjunction with the accompanying drawings.

[0036] Reference Figure 1 The present application provides a combined femoral stem prosthesis, comprising a proximal body 1, a narrow body 2 and a distal body 3 arranged in sequence, wherein a neck portion 4 is fixed to the side of the proximal body 1 away from the narrow body 2, a stem cone 5 is formed on the neck portion 4, and the axial direction of the stem cone 5 is inclined toward one side of the proximal body 1 along a direction from approaching to moving away from the proximal body 1; wherein the proximal body 1, the narrow body 2, the distal body 3 and the neck portion 4 are all pre-designed and processed into a variety of different models, that is, they have different structural proportions or sizes.

[0037] The proximal body 1, the narrow body 2 and the distal body 3 are inserted into the medullary cavity and cooperate with the medullary cavity. Since the shape of the medullary cavity is irregular and the medullary cavity structure varies greatly from person to person, the proximal body 1, the narrow body 2 or the distal body 3 of the corresponding size and structure are selected according to the patient's medullary cavity structure before surgery, and then the three are assembled to form a femoral stem prosthesis that is more compatible with the patient's medullary cavity structure; if the length, structure, etc. of the femoral stem prosthesis needs to be adjusted during postoperative revision, it is only necessary to replace the proximal body 1, the narrow body 2 or the distal body 3 of the corresponding model; in addition, if the length, inclination angle, etc. of the stem cone 5 needs to be adjusted during postoperative revision, it is only necessary to replace the neck 4 of the corresponding model; compared with the customized processing of the entire femoral stem prosthesis according to the patient's medullary cavity structure and size before surgery, the present application improves the applicability of the femoral stem prosthesis to different patients, so as to reduce the initial design and processing costs of the femoral stem prosthesis, and also simplifies the subsequent femoral stem prosthesis revision operation.

[0038] Specifically, refer to Figure 1 and Figure 2 The neck portion 4, the proximal body 1, the narrow body 2 and the distal body 3 are arranged in a fixed relationship, and the end of the distal body 3 close to the narrow body 2 is formed with a connecting rod 6 that is penetrated through the narrow body 2 and the inside of the distal body 3, the diameter of the connecting rod 6 is smaller than the end face diameter of the distal body 3 close to the connecting rod 6, and the end face of the distal body 3 is pressed against the end face of the narrow body 2, and the end of the connecting rod 6 facing away from the distal body 3 is inserted into the neck portion 4; the end face of the neck portion 4 close to the proximal body 1 is provided with an insertion hole 41 for inserting the end of the connecting rod 6, and the side of the neck portion 4 facing away from the proximal body 1 is penetrated with a fixing screw 7 screwed into the end face of the connecting rod 6.

[0039] When the entire femoral stem prosthesis needs to be assembled, the connecting rod 6 is passed through the neck 4, the proximal body 1 and the narrow body 2, and the fixing screw 7 is screwed so that the distal body 3 and the neck 4 tend to move toward each other until the distal body 3 and the neck 4 jointly clamp the proximal body 1 and the narrow body 2, thereby fixing the positions of the neck 4, the proximal body 1, the narrow body 2 and the distal body 3; in order to ensure the structural stability of the entire femoral stem prosthesis after assembly, the end of the connecting rod 6 facing away from the distal body 3 has a taper, and the diameter of this end of the connecting rod 6 gradually decreases along the direction from approaching to away from the distal body 3, and the insertion hole 41 is adapted to the connecting rod 6, thereby forming a reliable taper fit between the connecting rod 6 and the neck 4.

[0040] Reference Figure 1 and Figure 2In order to make the femoral stem prosthesis have a good bionic structure, the proximal body 1 has two oppositely arranged first mating surfaces 11 and two oppositely arranged second mating surfaces 12, the first mating surface 11 and the second mating surface 12 are adjacent to each other, and the axis of the stem cone 5 is located between the two second mating surfaces 12; wherein, a bionic protrusion 8 is formed on the first mating surface 11 which is farther away from the stem cone 5, and the bionic protrusion 8 is located at the end of the proximal body 1 away from the narrow body 2, and the bionic protrusion 8 protrudes toward the side away from the stem cone 5; in this way, the proximal body 1 can better adapt to the proximal shape of the medullary cavity after being inserted into the medullary cavity, and the medullary cavity wall can support the proximal body 1 by supporting the bionic protrusion 8, thereby making the entire femoral stem prosthesis have an anti-sinking effect, that is, it has good stability after surgery.

[0041] Further, see Figure 2 and Figure 3 The first mating surface 11 is an arc surface and there is a taper between the two first mating surfaces 11, and the distance between the two first mating surfaces 11 gradually increases from approaching to away from the narrow portion body 2; there is a taper between the planes where the two second mating surfaces 12 are located, and the distance between the two planes gradually increases from approaching to away from the narrow portion body 2; in addition, combined with Figure 4 There is an angle between the sides of the two second mating surfaces 12 close to the handle cone 5, and the distance between the two sides gradually decreases along the direction from close to to far away from the bionic protrusion 8; in this way, the proximal body 1 forms a wedge-shaped structure in three directions. When the proximal body 1 is inserted into the medullary cavity, each surface of the proximal body 1 forms a taper fit with the wall of the medullary cavity. When the proximal body 1 is subjected to pressure from human bones or tissues, the bone ingrowth effect on the surface of the proximal body 1 is effectively improved.

[0042] In order to further improve the bone ingrowth effect of the entire femoral stem prosthesis, the proximal body 1, the narrow body 2 and the distal body 3 are all made of 3D printed trabecular structures, so that the surfaces of the three components have a good bone ingrowth effect, thereby improving the postoperative stability of the femoral stem prosthesis.

[0043] Reference Figure 1 and Figure 2 The circumferential surface of the narrow portion body 2 also has a taper, and the diameter of the narrow portion body 2 gradually decreases along the direction from approaching to away from the proximal body 1, and the diameter of the large diameter end of the narrow portion body 2 is equal to or smaller than the end face diameter of the proximal body 1 close to the narrow portion body 2; when the femoral stem prosthesis is inserted into the medullary cavity, the narrow portion body 2 should correspond to the narrowest part of the medullary cavity, and the medullary cavity wall radially limits the circumferential surface of the narrow portion body 2, and because the circumferential surface of the narrow portion body 2 has a taper, a taper fit is formed between the narrow portion body 2 and the medullary cavity wall, which further improves the postoperative stability of the femoral stem prosthesis.

[0044] In order to facilitate the insertion of the femoral stem prosthesis into the medullary cavity, the end of the distal body 3 away from the narrow portion body 2 has a taper, and the diameter of this end of the distal body 3 gradually decreases along the direction from close to to away from the narrow portion body 2, so that when inserted into the medullary cavity, the pressure caused by the end face of the distal body 3 on the medullary cavity can be effectively reduced, and the resistance received during the insertion of the femoral stem prosthesis can be reduced; in addition, during subsequent patient movement, if the distal end of the femoral stem prosthesis moves inside the medullary cavity, the tapered end can effectively reduce the possibility of the distal body 3 colliding with the medullary cavity wall and causing pain to the patient.

[0045] Further, see Figure 1 and Figure 2 The circumferential surface of the distal body 3 is provided with a plurality of deformation grooves 31 penetrating the end surface of the distal body 3 away from the narrow body 2. The deformation grooves 31 are provided through the circumferential surface of the distal body 3 and the plurality of deformation grooves 31 are distributed at intervals along the circumference of the distal body 3. The deformation grooves 31 are interconnected so that the distal body 3 can produce elastic deformation when subjected to radial pressure. In this embodiment, four deformation grooves 31 are provided and are distributed at equal intervals around the axis of the distal body 3. The four deformation grooves 31 together form a "cross"-shaped groove; on the one hand, by reducing the end surface area of ​​the distal body 3 to further reduce The end surface of the distal body 3 exerts pressure on the medullary cavity, thereby facilitating the penetration of the distal body 3; on the other hand, when the femoral stem prosthesis is to be inserted into the medullary cavity, the peripheral wall of the distal body 3 is pressed to deform the distal body 3, thereby facilitating the distal body 3 to pass through the osteotomy surface and enter the medullary cavity; after the distal body 3 is inserted into the medullary cavity, the medullary cavity wall exerts a certain pressure on the peripheral surface of the distal body 3 by causing the distal body 3 to produce elastic deformation, and the distal body 3 is then deformed to better adapt to the shape of the medullary cavity, thereby improving the postoperative stability of the femoral stem prosthesis in the medullary cavity.

[0046] In summary, the use process of the present application is: the neck 4, the proximal body 1, the narrow body 2 and the distal body 3 are detachably connected to each other. Compared with the customized processing of the entire femoral stem prosthesis according to the patient's medullary cavity structure and size before surgery, the present application improves the applicability of the femoral stem prosthesis to different patients, so as to reduce the initial design and processing costs of the femoral stem prosthesis, and also simplifies the subsequent femoral stem prosthesis revision operation.

[0047] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A combined femoral stem prosthesis, characterized in that: It includes a proximal body (1), a narrow part body (2), and a distal body (3) arranged in sequence. A neck part (4) is provided on one side of the proximal body (1) facing away from the narrow part body (2), and a shank taper (5) is formed on the neck part (4); the neck part (4), the proximal body (1), the narrow part body (2), and the distal body (3) are detachably fixed together; The shank taper (5) inclines towards one side of the proximal body (1) along the direction from close to far away from the proximal body (1). A bionic protrusion (8) is formed on one side of the proximal body (1), and the bionic protrusion (8) protrudes towards the direction away from the direction towards which the shank taper (5) faces; The proximal body (1) includes two relatively arranged first mating surfaces (11), and the bionic protrusion (8) is formed on the first mating surface (11) facing away from the shank taper (5); the distance between the two first mating surfaces (11) gradually increases along the direction from close to far away from the narrow part body (2); The proximal body (1) further includes two relatively arranged second mating surfaces (12), and the distance between the planes where the two second mating surfaces (12) are located gradually increases along the direction from close to far away from the narrow part body (2); there is an included angle between the sides of the two second mating surfaces (12) close to the shank taper (5), and the distance between the two sides gradually decreases along the direction from close to far away from the bionic protrusion (8); A connecting rod (6) that sequentially penetrates the narrow part body (2) and the proximal body (1) is formed on the distal body (3). The end face of the distal body (3) abuts against the end face of the narrow part body (2). The connecting rod (6) extends into the neck part (4), and a fixing screw (7) screwed on the end face of the connecting rod (6) is arranged inside the neck part (4).

2. The modular femoral stem prosthesis according to claim 1, wherein: An insertion hole (41) adapted to the end of the connecting rod (6) is formed on the surface of the neck part (4) close to the proximal body (1). One end of the connecting rod (6) facing away from the distal body (3) has a taper, and the diameter of the part of the connecting rod (6) with a taper gradually decreases along the direction from close to far away from the distal body (3).

3. The modular femoral stem prosthesis according to claim 1, wherein: One end of the distal body (3) facing away from the narrow part body (2) has a taper, and the diameter of the part of the distal body (3) with a taper gradually decreases along the direction from close to far away from the narrow part body (2).

4. A combined femoral stem prosthesis according to claim 1 or 3, characterized in that: A plurality of deformation grooves (31) for the distal body (3) to deform towards the direction close to its own axis are formed on the peripheral wall of the distal body (3), and the deformation grooves (31) are distributed at intervals along the circumferential direction of the distal body (3).

5. A combined femoral stem prosthesis according to claim 1, characterized in that: The diameter of the narrow part body (2) gradually increases along the direction from the distal body (3) to the proximal body (1).

6. The modular femoral stem prosthesis according to claim 1, characterized in that: Part or all of the proximal body (1), the narrow part body (2), and the distal body (3) are 3D printed trabecular bone structures.

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