A hip joint femoral stem and a hip joint prosthesis

Abstract

The femoral stem of the hip joint provided by the present invention has an adjustable stem body, which includes an upper end portion, a connecting portion and a lower end portion. The upper end portion and the lower end portion are respectively threadedly connected to the connecting portion. The setting of the protruding portion at the lower end of the upper end portion, the setting of the first step and the second step of the connecting portion, and the setting of the outer thread lengths of the upper end portion and the lower end portion all play crucial roles in adjusting the length of the stem body. Scale marks for facilitating the display of the adjusted length are also provided on the outer surfaces of the connecting portion and the lower end portion. After the upper end portion, the connecting portion and the lower end portion are threadedly connected, the diameter of the stem body as a whole decreases step by step from top to bottom. The femoral stem of the present invention is more stable after the length adjustment and fitting, has stronger adaptability, is convenient for assembly and disassembly, is beneficial to conventional replacement and postoperative revision, and can meet the personalized needs of different patients.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and more particularly, to a hip femoral stem and a hip joint prosthesis, which can be used to replace a damaged human hip joint, facilitate postoperative revision, and meet the personalized needs of patients for artificial hip joint prostheses. Background Art

[0002] The hip joint is an important hub connecting the human torso and the lower body, which is related to the degree of freedom of movement of the lower limbs. However, if the hip joint develops diseases or degenerates, such as degenerative arthritis, rheumatoid arthritis, avascular necrosis of the femoral head, femoral neck fracture, hip dysplasia, hip bone tumor, etc., it often causes limited limb movement and pain in patients, affecting the quality of life of patients, and even seriously losing the ability to work. At this time, artificial hip joint replacement surgery is usually performed. Artificial hip joint replacement surgery refers to the method of implanting an artificial joint prosthesis made of materials with good biocompatibility and mechanical properties into the body through surgery to replace the femoral head and / or acetabular joint surface damaged by diseases or injuries. Its purpose is to remove the lesion, relieve or eliminate joint pain, reconstruct the anatomical structure of the human hip joint, and restore the joint movement and original physiological function.

[0003] An artificial hip joint implanted in the human body generally consists of components such as a femoral stem, an acetabular cup, and a femoral head. Among them, the femoral stem, as a connecting component between the human femur and the distal end of the human body, plays a role of fixation and support in the human body. There are various forms of the femoral stem, and the straight stem type and the curved stem type are widely used. Their structural design and material properties directly affect the treatment effect of hip joint replacement surgery. For example, the Chinese patent document with the application number 201210043649.2 relates to a femoral stem of an artificial hip joint, which is an integral structure. There is an opening at the lower end of the stem body, and bone fragments are filled in the stem body. There is a rough surface at the upper end of the stem body, so as to achieve a good surgical effect; however, the shape of the collar at the upper end of its stem body is in a right-angle form, which does not conform to the morphological characteristics of the corresponding collar of the natural hip joint. There are various forms of the femoral stem, and the straight stem type and the curved stem type are widely used. After hip joint prosthesis replacement, there may be persistent pain, limited range of motion, and even phenomena such as prosthesis loosening and sinking; in addition, the Chinese patent document with the application number 201711133821.2 relates to a femoral stem prosthesis of a hip joint, which is also an integral structure, including a stem body formed by the proximal end of the femoral stem and the distal end of the femoral stem. A neck head is formed by the upward inclination of one side edge at the top of the proximal end of the femoral stem. A plurality of hemispherical protrusions are evenly distributed on the outer surface of the proximal end of the femoral stem. Autologous bone fragments are filled and pressed into the gaps between the plurality of protrusions. The outer surface of the stem body in contact with the femoral medullary cavity is covered with a sprayed coating, so as to achieve a good surgical effect. The prostheses involved in the above two patent documents are all general conventional artificial hip joint prostheses, and due to factors such as height, body shape, age, and race, the artificial hip joint cannot meet the needs of different patients with a single size and angle, and the stability and self-locking properties are not ideal, and it is also impossible to perform postoperative revision better and more quickly, and cannot meet the personalized needs of different patients. Therefore, how to solve the above technical problems is an urgent research topic in this field.

[0004] In view of the problems existing in the above-mentioned prior art, there is an urgent need for an improved femoral stem of an artificial hip joint and its hip joint prosthesis that is easy to adjust, has high stability, strong adaptability, is conducive to revision, and is safe and reliable, so as to make up for the deficiencies in the prior art and meet the personalized needs of different patients. Summary of the Invention

[0005] In the description of the present invention, it should be understood that the terms "both ends", "upper", "lower", "axial direction", "circumferential direction", "top", "bottom", "middle", "length", "inner", "outer", etc. indicating the orientation or position relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present invention.

[0006] The object of the present invention is to propose a hip joint femoral stem and a hip joint prosthesis for replacing a damaged human hip joint in view of the above technical problems. The femoral stem can be adjusted according to factors such as the patient's height, body type, age, race, etc., to meet the personalized needs of the patient for the artificial hip joint prosthesis, with good stability and being conducive to postoperative revision, improving the applicability of the hip joint prosthesis and the surgical success rate, reducing the surgical risk, and achieving an ideal therapeutic effect.

[0007] To achieve the above object, the hip joint femoral stem provided by the present invention includes a top joint part configured as a frustum of a cone, a neck and head integrally formed with the top joint part and configured to be inclined, and a stem body. Among them, the top joint part is configured as a frustum of a cone, the stem body is an adjustable stem body and includes an upper end part integrally formed with the neck and head, a connecting part and a lower end part. The upper end part, the connecting part and the lower end part are coaxial and are arranged at an angle of 120 - 135° with the neck and head. The lower end of the upper end part has a hollow inner cavity, and a protruding part axially extending from the bottom of the hollow inner cavity. An annular groove is formed between the outer wall of the hollow inner cavity and the protruding part. The length of the protruding part extends beyond the outer wall, and at least the part exceeding the outer wall has an external thread. The thickness of the end of the outer wall gradually becomes thinner from top to bottom, so that the outer surface of the end of the hollow inner cavity is tapered. The inner surface of the hollow inner cavity is an overall smooth and flat plane; the connecting part is a hollow cylinder, and a first step protruding inward is provided on the inner wall in the middle and upper part. The surface of the first step has a thread structure that is in threaded connection with the external thread of the protruding part, so that the upper end part and the connecting part form a threaded connection. When the protruding part and the connecting part are in threaded connection, the upper end of the connecting part just inserts into the annular groove of the upper end part, so as to form a tight and stable fit. A second step protruding inward is provided on the inner wall in the middle and lower part of the connecting part. The surface of the second step has a thread structure that cooperates with the lower end part. The thickness of the lower end of the connecting part gradually becomes thinner from top to bottom, so that the outer surface of the lower end of the connecting part is tapered; the lower end part is cylindrical and has an external thread at the upper end that cooperates with the thread structure of the second step, so that the lower end part and the connecting part form a threaded connection. When the lower end part and the connecting part are in threaded connection, the lower end of the connecting part just wraps the outer wall of the lower end part, so as to form a tight and stable fit. The bottom of the lower end part is tapered. After the upper end part, the connecting part and the lower end part are mutually in threaded connection and cooperate, the diameter of the stem body as a whole becomes smaller step by step from top to bottom, and the transition is in a natural transition state without protruding edges or shoulders.

[0008] Preferably, the connecting portion has a smooth inner wall between the first step and the second step, and a hollow chamber is formed between the first step and the second step after the upper end portion, the connecting portion, and the lower end portion are threadedly connected. The hollow chamber becomes smaller as the external thread of the protruding portion and the external thread of the lower end portion are screwed in.

[0009] Furthermore, threaded holes are respectively provided at the first step and the second step of the connecting portion in a direction perpendicular to the axis. The threaded holes are used to cooperate with screws or bolts to limit and fix the adjusted adjustable handle body.

[0010] Furthermore, an elastic pad or ratchet teeth are fixed to the bottom of the screw or bolt, so as to prevent the protruding portion or the lower end portion from continuing to be screwed in or out along the threaded structure of the first step or the second step when abutting against the external thread of the protruding portion or the lower end portion, thereby limiting and fixing the adjusted adjustable handle body.

[0011] Preferably, a compression spring is connected between the protruding portion and the lower end portion after the upper end portion, the connecting portion, and the lower end portion are threadedly connected. The compression spring is compressed as the external thread of the protruding portion and the external thread of the lower end portion are screwed into the connecting portion.

[0012] Preferably, the threaded portion of the lower end portion accounts for one-fourth to one-third of its total length. The free end at the bottom of the lower end portion is conical and has a cross-shaped through groove. The length of the cross-shaped through groove extending axially accounts for about one-fourth of the total length of the lower end portion, which can further prevent rotation to ensure the stability of the bottom of the handle body after implantation.

[0013] Furthermore, an anti-rotation member is provided on the outer surface of the upper end portion or the connecting portion. The anti-rotation member is a plurality of ribs arranged axially (not shown in the figure), or a plurality of elongated grooves arranged axially.

[0014] Furthermore, the inner wall of the bottom of the lower end portion gradually approaches the axis direction from top to bottom, so that a triangular cavity with a downward tip is formed between the lower end portion and the lower end of the connecting portion.

[0015] In addition, the present invention also provides a hip joint prosthesis, which includes the above-mentioned hip joint femoral stem, a ball head connected to the femoral stem in a matching manner, an acetabular liner wrapping the ball head, and an acetabular outer cup fixedly connected to the acetabular liner. The concave inner surface of the acetabular outer cup is used to receive the acetabular liner and is fixedly connected by means of nesting, connection or snap-fastening, etc. A plurality of through holes for screwing to fix the acetabular outer cup to the pelvis are provided at the bottom of the acetabular outer cup; the polished concave inner surface of the acetabular liner is used to cooperate with the outer surface of the ball head and is used to receive the outer spherical surface of the ball head. The ball head includes a polished sphere, an outer spherical surface that cooperates with the inner surface of the acetabular liner, a horizontal end face milled out of the sphere, and an inner conical frustum that is concave along the horizontal end face of the sphere and is used to receive the top joint part of the femoral stem.

[0016] The femoral stem and the ball head are firmly connected through a conical frustum. Specifically, the round table-shaped top joint part of the femoral stem is inserted into the inner conical frustum-shaped concave surface of the ball head and fixed into an integral structure, and the ball head can rotate within the acetabular liner.

[0017] The materials of the acetabular outer cup and the femoral stem are tantalum, tantalum alloy or other medical metal materials. The acetabular outer cup has a porous surface structure. The acetabular liner can be made of alumina ceramic, polyethylene, polyether ether ketone or metal materials, etc. The material of the ball head is alumina ceramic or medical metal material.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] The present invention solves many problems existing in the hip joint femoral stem in the prior art, such as the length cannot be adjusted, the stability is poor, the applicability is low, it is not conducive to postoperative revision, the surgical risk is high, it cannot meet the personalized needs of patients for artificial hip joint prostheses, and the ideal treatment effect cannot be achieved. The present invention creatively proposes an adjustable hip joint femoral stem, which includes a round table-shaped top joint part, a head-neck part, and a stem body. Among them, the stem body includes an upper end part integrally formed with the head-neck, a connecting part and a lower end part. The upper end part and the lower end part are respectively threadedly connected to the connecting part. The setting of the protruding part at the lower end of the upper end part, the setting of the specific structure of the connecting part, and the setting of the external thread lengths of the upper end part and the lower end part all play crucial roles in adjusting the length of the stem body. After the upper end part, the connecting part and the lower end part are threadedly connected in cooperation, the diameter of the stem body as a whole decreases step by step from top to bottom, and the transition is in a natural transition state without protruding edges or shoulders. The femoral stem of the present invention is convenient for length adjustment, more stable after adjustment and adaptation, has strong adaptability, is convenient for assembly and disassembly, is conducive to conventional replacement and postoperative revision, is safe and reliable, can meet the personalized needs of different patients, and achieves the expected effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure after the hip joint femoral stem of the present invention is assembled.

[0021] Figure 2 It is a schematic diagram of the upper end structure of the present invention with a cylindrical protrusion.

[0022] Figure 3 It is a schematic diagram of the upper end structure of the present invention with a stepped protrusion.

[0023] Figure 4 It is a schematic diagram of the overall structure of the hip joint femoral stem of another embodiment of the present invention.

[0024] Figure 5 It is a schematic diagram of the structure after the hip joint prosthesis provided by the embodiment of the present invention is assembled. Detailed implementation manners

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other related embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] Embodiment 1

[0027] Refer to the appendix Figure 1-2As shown in the figure, a hip joint femoral stem provided by the present invention includes a top joint portion 1 configured as a frustum of a cone, a neck 2 integrally formed with the top joint portion 1 and configured to be inclined, and a stem body 3. Among them, the stem body 3 is an adjustable stem body and includes an upper end portion 4, a connecting portion 5 and a lower end portion 6 integrally formed with the neck 2. The upper end portion 4, the connecting portion 5 and the lower end portion 6 are coaxial and are arranged at an angle of 120 - 135° with the neck 2. This angle conforms to the anatomical parameters of the Chinese hip joint and can be customized according to individual differences. The lower end of the upper end portion 4 has a hollow inner cavity and a protruding portion 7 axially extending from the bottom of the hollow inner cavity. An annular groove 8 is formed between the outer wall of the hollow inner cavity and the protruding portion 7. The protruding portion 7 extends beyond the outer wall, and at least the part exceeding the outer wall has an external thread 9. The thickness of the end of the outer wall gradually thins from top to bottom, so that the outer surface of the end of the hollow inner cavity is tapered. The inner surface of the hollow inner cavity is an overall smooth and flat plane; the connecting portion 5 is a hollow cylinder and has a first step 10 protruding inward at the inner wall in the upper middle part. The surface of the first step 10 has a thread structure that mates with the external thread 9 of the protruding portion 7, so that the upper end portion 4 and the connecting portion 5 form a threaded connection. When the protruding portion 7 and the connecting portion 5 are threaded together, the upper end of the connecting portion 5 just inserts into the annular groove 8 of the upper end portion 4, thus forming a tight and stable fit. The inner wall of the middle and lower part of the connecting portion 5 has a second step 11 protruding inward. The surface of the second step 11 has a thread structure that mates with the lower end portion 6. The thickness of the lower end of the connecting portion 5 gradually thins from top to bottom, so that the outer surface of the lower end of the connecting portion 5 is tapered; the lower end portion 6 is cylindrical and has an external thread 12 at the upper end that mates with the thread structure of the second step 11, so that the lower end portion 6 and the connecting portion 5 form a threaded connection. When the lower end portion 6 and the connecting portion 5 are threaded together, the lower end of the connecting portion 5 just wraps the outer wall of the lower end portion 6, thus forming a tight and stable fit. Scale marks are provided on the outer surfaces of the connecting portion 5 and the lower end portion 6 to more intuitively display the adjusted length of the stem body. The bottom of the lower end portion 6 is tapered. After the upper end portion 4, the connecting portion 5 and the lower end portion 6 are threaded together, the diameter of the stem body 3 as a whole gradually becomes smaller in a stepped manner from top to bottom, and the transition is in a natural transition state without protruding edges or shoulders.

[0028] Further, the total length of the adjustable stem body 3 is 100 - 190 mm, and its length can be adjusted according to the needs of the patient. Among them, the external thread 9 of the protruding portion 7 in the upper end portion 4 accounts for one-third to one-half of the entire length of the protruding portion 7, or the protruding portion 7 exceeding the end of the outer wall has an external thread 9, while the protruding portion 7 located in the hollow inner cavity does not have an external thread.

[0029] Furthermore, as Figure 1-2 shown, the protruding part 7 is cylindrical, and the external thread 9 of the protruding part 7 is threadedly connected to the first step 10 of the connecting part 5. The maximum adjustable degree is such that the top end of the connecting part 5 abuts against the bottom of the annular groove 8.

[0030] Preferably, the connecting part 5 has a smooth inner wall between the first step 10 and the second step 11, and a hollow chamber 13 is formed between the first step 10 and the second step 11 after the upper end part 4, the connecting part 5, and the lower end part 6 are threadedly connected. The hollow chamber 13 becomes smaller as the external thread 9 of the protruding part 7 is screwed into the external thread 12 of the lower end part 6.

[0031] Furthermore, as Figure 1 shown, threaded holes 14 are provided at the first step 10 and the second step 11 of the connecting part 5 respectively along a direction perpendicular to the axis. The threaded holes 14 are used to cooperate with screws or bolts to limit the adjustable handle body 3 after adjustment, so as to avoid unnecessary changes in the length of the adjustable handle body 3 after adjustment.

[0032] In this embodiment, the material of the hip joint femoral stem is tantalum, tantalum alloy or other suitable medical metal materials, and the materials of the top combining part 1, the head and neck 2, and the handle body 3 are the same or different.

[0033] Furthermore, an elastic pad or a ratchet is fixed to the bottom of the screw or bolt, so as to prevent the protruding part 7 or the lower end part 6 from continuing to be screwed into or out of the threaded structure of the first step 10 or the second step 11 when abutting against the external thread of the protruding part 7 or the lower end part 6, thereby limiting and fixing the adjustable handle body 3 after adjustment.

[0034] Preferably, the external thread 12 of the lower end part 6 accounts for one-fourth to one-third of its total length. The free end 15 at the bottom of the lower end part 6 is conical and has a cross-shaped through groove 16. The length of the cross-shaped through groove 16 extending along the axis accounts for about one-fourth of the total length of the lower end part 6, making it more convenient to insert the lower end part 6 into the femoral cavity and facilitating the surrounding tissue to enter the cross-shaped through groove 16. The cross-shaped through groove 16 has a frustum-shaped cross-section that is narrower at the top and wider at the bottom along the axis, thereby further preventing rotation to ensure the stability of the bottom of the handle body after implantation; and it is also beneficial for vertical removal when revision is needed.

[0035] Furthermore, an anti-rotation member is provided on the outer surface of the upper end part 4 or the connecting part 5. The anti-rotation member is a plurality of rib strips (not shown in the figure) arranged along the axis, or a plurality of elongated grooves arranged along the axis.

[0036] Furthermore, as Figure 1As shown, the bottom inner wall of the lower end portion 6 gradually approaches the axis direction from top to bottom, so that a triangular cavity 17 with a pointed end facing downwards is formed between the lower end portion 6 and the lower end of the connecting portion 5.

[0037] Embodiment 2

[0038] Refer to the appendix Figure 3-4 As shown, the structure of this embodiment is basically the same as that of Embodiment 1. The difference is that in this embodiment, the protruding portion 7 is stepped.

[0039] Specifically, as Figure 3 shown, the protruding portion 7 is stepped with a thicker upper part and a thinner lower part. The thicker part has a smooth outer surface, the thinner part has an external thread 9, and there is a step 18 between the thicker part and the thinner part. The external thread 9 located in the thinner part is threadedly connected to the first step 10 of the connecting portion 5, and the maximum adjustable degree is such that the first step 10 of the connecting portion 5 abuts against the step 18; due to the existence of the thicker part, the annular groove 8 in this embodiment is smaller than the annular groove 8 in Embodiment 1.

[0040] In this embodiment, both the upper end portion 4 and the lower end portion 6 are hollow structures, and reinforcing ribs or stiffeners are provided inside the hollow to save materials and play a stable supporting role. After the upper end portion 4, the connecting portion 5 and the lower end portion 6 are threadedly connected, they can form an angle of 120° with the head and neck 2.

[0041] Embodiment 3

[0042] Refer to the appendix Figure 4 As shown, the structure of this embodiment is basically the same as that of Embodiment 1 or Embodiment 2. The difference is that in this embodiment, a compression spring 19 is provided in the hollow chamber 13.

[0043] Specifically, after the upper end portion 4, the connecting portion 5, and the lower end portion 6 are threadedly connected, a compression spring 19 is connected between the protruding portion 7 and the lower end portion 6. The compression spring 19 is compressed as the external thread 9 of the protruding portion 7 and the external thread 12 of the lower end portion 6 are screwed into the connecting portion 5. When renovation is required, the compression spring 19 can pop out more conveniently for renovation; in this embodiment, after the upper end portion, the connecting portion, and the lower end portion are threadedly connected, they can form an angle of 135° with the head and neck.

[0044] In addition, as an alternative, in this embodiment, there is no need to provide threaded holes at the first step 10 and the second step 11 of the connecting portion 5. The elastic force of the compression spring 19 is used to prevent the natural screwing in or out of the external thread, and only by relying on external force can the external thread be screwed in or out. Thus, the adjusted adjustable handle body 3 is limited, avoiding unnecessary changes in the length of the adjustable handle body 3 after the adjustment is determined.

[0045] Example 4

[0046] Refer to the appendix Figure 5 As shown, this embodiment also provides a hip joint prosthesis, which includes the hip joint femoral stem defined in any one of the above-mentioned Embodiments 1-3, a ball head 20 connected to the femoral stem in a matching manner, an acetabular liner 21 wrapping the ball head 20, and an acetabular outer cup 22 fixedly connected to the acetabular liner. The concave surface of the acetabular outer cup 22 is used to receive the acetabular liner 21 and is fixedly connected by means of nesting, connection or snap-fastening, etc. A plurality of through holes 23 for screwing to fix the acetabular outer cup 22 to the pelvis are provided at the bottom of the acetabular outer cup 22; the polished concave surface of the acetabular liner 21 is used to cooperate with the outer surface of the ball head 20 and is used to receive the outer spherical surface of the ball head 20. The ball head 20 includes a polished sphere, an outer spherical surface cooperating with the inner surface of the acetabular liner 21, a horizontal end face milled out of the sphere, and an inner conical frustum recessed along the horizontal end face of the sphere and used to receive the top joint of the femoral stem.

[0047] The femoral stem and the ball head 20 are firmly connected by a conical frustum. Specifically, the round table-shaped top joint 1 of the femoral stem is inserted into the inner conical frustum-shaped concave surface of the ball head 20 and fixed into an integral structure, and the ball head 20 can rotate within the acetabular liner 21.

[0048] The materials of the acetabular outer cup 22 and the femoral stem are tantalum, tantalum alloy or other medical metal materials. The acetabular outer cup 22 has a porous surface structure. The acetabular liner 21 can be made of alumina ceramic, polyethylene, polyether ether ketone or metal material, etc. The material of the ball head 20 is alumina ceramic or medical metal material.

[0049] The number of through holes 23 on the acetabular outer cup 22 is 3-5.

[0050] Further, as is well-known to those skilled in the art, other structures can also be additionally provided in this embodiment to facilitate necessary control and operation during implantation or revision, and to ensure the stability after implantation, without departing from the inventive concept of the present invention and without structural interference between structures, and shall be implemented by those skilled in the art.

[0051] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and can be implemented in other specific forms or combinations without departing from the spirit or basic characteristics of the present invention. Therefore, non-restrictively, the protection scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0052] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A hip joint femoral stem, comprising a truncated cone-shaped top joint portion, a head and neck integrally formed with the top joint portion and configured to be inclined, and a stem body, characterized in that: The handle body is an adjustable handle body and includes an upper end, a connecting part and a lower end integrally formed with the head and neck, the lower end of the upper end having a hollow inner cavity and a protrusion axially extending from the bottom of the hollow inner cavity, an annular groove being formed between the outer wall of the hollow inner cavity and the protrusion, the protrusion extending longer than the outer wall, and at least the part exceeding the outer wall has an external thread, the end of the outer wall gradually becomes thinner from top to bottom, so that the outer surface of the end of the hollow inner cavity is conical and the inner surface of the hollow inner cavity is a smooth and flat plane as a whole; the connecting part is hollow cylindrical and is provided with a first step protruding inwardly at the middle and upper inner wall, the surface of the first step has a threaded structure that cooperates with the external thread of the protrusion, and when the protrusion is threadedly connected to the connecting part, the upper end of the connecting part is just inserted into the annular groove of the upper end, and the middle and lower inner wall of the connecting part has a second step protruding inwardly The lock member is a pair of locks which are connected along the length of the handle to the spring which is coupled to the locking member so that the locking member can be locked in a desired manner.

2. The hip joint femoral stem according to claim 1, wherein the upper end portion, the connecting portion and the lower end portion are coaxial and are arranged at an angle of 120-135 degrees with the head and neck.

3. The hip joint femoral stem according to claim 2, wherein the total length of the adjustable stem is 100-190 mm, and the length can be adjusted according to the patient's needs, wherein: The external thread of the protrusion in the upper end portion occupies one third to one half of the entire length of the protrusion, or the protrusion beyond the outer wall end portion has an external thread, while the protrusion located in the hollow inner cavity has no external thread.

4. The hip joint femoral stem according to claim 2, wherein the connecting part has a smooth inner wall between the first step and the second step, and a hollow chamber is formed between the first step and the second step after the upper end, the connecting part, and the lower end are threadedly connected, and the axial space of the hollow chamber becomes smaller as the external thread of the protrusion and the external thread of the lower end are continuously screwed in.

5. The hip joint femoral stem according to claim 2, wherein the external thread of the lower end portion occupies one quarter to one third of its total length, the lowermost free end of the lower end portion is conical and has a cross groove, the axial extension length of the cross groove occupies about one quarter of the total length of the lower end portion, and the axial cross-section of the cross groove is a frustum shape that is narrow at the top and wide at the bottom.

6. The hip joint femoral stem according to any one of claims 1-5, wherein the protrusion is cylindrical, the external thread of the protrusion is threadedly connected to the first step of the connecting part, and the maximum adjustable degree is to make the top of the connecting part abut against the bottom of the annular groove.

7. The hip joint femoral stem according to any one of claims 1 to 5, wherein the connecting portion is provided with threaded holes at the first step and the second step along a direction perpendicular to the axis, the threaded holes being used to be combined with screws or bolts to limit the adjusted adjustable handle body, wherein: An elastic pad or ratchet is fixed to the bottom of the screw or bolt to prevent the protrusion or lower end from continuing to screw in or out along the thread structure of the first step or the second step when abutting against the external thread of the protrusion or lower end.

8. A hip joint prosthesis containing a hip joint femoral stem according to any one of claims 1 to 7, wherein the hip joint prosthesis comprises a ball head connected to the femoral stem, an acetabulum liner wrapping the ball head, and an acetabulum outer cup fixedly connected to the acetabulum liner, the inner concave surface of the acetabulum outer cup being used to receive the acetabulum liner and being fixedly connected by nesting, connecting or snapping, the bottom of the acetabulum outer cup being provided with a plurality of through holes for screw fixing the acetabulum outer cup and the pelvis; the polished inner concave surface of the acetabulum liner being used to cooperate with the outer surface of the ball head and to receive the outer spherical surface of the ball head, the ball head comprising a polished sphere, an outer spherical surface cooperating with the inner surface of the acetabulum liner, a horizontal end face milled out of the sphere, an inner frustum concave along the horizontal end face of the sphere and used to receive the top joint of the femoral stem, and the femoral stem and the ball head are firmly connected through the frustum.

9. The hip joint prosthesis according to claim 8, wherein the truncated cone-shaped top joint of the femoral stem is inserted into the inner conical concave surface of the ball head and fixed into an integrated structure, the ball head can rotate in the acetabulum liner, and the number of through holes on the acetabulum outer cup is 3-5.

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