Femoral stem and hip joint prosthesis

Abstract

The invention relates to a femoral stem and a hip joint prosthesis. The femoral stem comprises a near-end prosthesis stem, a far-end prosthesis stem and a locking rod. A mounting channel is arranged in the near-end prosthesis handle, the mounting channel penetrates through the near-end prosthesis handle in the direction from the near end of the near-end prosthesis handle to the far end of the near-end prosthesis handle, and a crimping surface is arranged on the near-end prosthesis handle; the far-end prosthesis handle is detachably mounted at the far end of the near-end prosthesis handle, and the far-end prosthesis handle is provided with an anti-retreating structure; one end of the locking rod penetrates through the mounting channel and abuts against the crimping surface, and the other end of the locking rod is connected with the far-end prosthesis handle. The femoral stem can pressurize a human body femoral metaphyseal osteotomy surface and a human body femoral shaft osteotomy surface, so that the contact area between the two osteotomy surfaces is increased, and the stability and the healing speed after the femoral stem is implanted are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a femoral stem and a hip joint prosthesis. Background Art

[0002] In THA (total hip arthroplasty), the femoral stem is a component connecting the artificial femoral head and the human femur. It needs to have sufficient strength, stability and biocompatibility to ensure tight bonding with the human femur after implantation and prevent complications such as loosening, infection or rejection.

[0003] When treating CROWE type IV DDH (congenital hip dysplasia), due to excessive upward displacement of the patient's femoral head, problems such as a smaller inner diameter of the human femoral shaft, shape variation, and increased anteversion angle occur. These problems bring great difficulties and risks to the implantation of traditional femoral stems. To solve these problems, a common method is to truncate the human femur below the lesser trochanter, then dock the truncated metaphyseal end of the human femoral shaft and the human femoral shaft together, and then implant the femoral stem into it.

[0004] However, after implanting the femoral stem in the prior art, it cannot be ensured that the osteotomy surfaces of the human femoral metaphyseal end and the human femoral shaft are in complete contact. When there is a large gap between the two osteotomy surfaces, it will affect the formation of new bone tissue between the two osteotomy surfaces, thereby affecting the healing speed and quality after femoral stem implantation. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to some extent.

[0006] To this end, in a first aspect, an embodiment of the present invention provides a femoral stem, which can apply pressure to the osteotomy surfaces of the human femoral metaphyseal end and the human femoral shaft to increase the contact area between the two osteotomy surfaces, facilitating the improvement of the stability and healing speed after femoral stem implantation.

[0007] The femoral stem of an embodiment of the present invention includes: a proximal prosthesis stem, an installation channel is provided in the proximal prosthesis stem, the installation channel penetrates the proximal prosthesis stem in the direction from the proximal end to the distal end of the proximal prosthesis stem, and a crimping surface is provided on the proximal prosthesis stem; a distal prosthesis stem, the distal prosthesis stem is detachably installed at the distal end of the proximal prosthesis stem, and the distal prosthesis stem is provided with an anti-retreat structure; one end of the distal prosthesis stem is inserted into the installation channel, a tab is provided on one of the outer wall of the distal prosthesis stem and the proximal prosthesis stem, and a slot is provided on the other, and the tab is snap-fitted with the slot; a locking rod, one end of the locking rod penetrates through the installation channel and abuts against the crimping surface, the other end of the locking rod is connected to the distal prosthesis stem, and the proximal prosthesis stem and the distal prosthesis stem are pressed and fitted together by the locking rod.

[0008] For the femoral stem according to an embodiment of the present invention, when installing the femoral stem, the distal prosthesis stem can be first implanted into the intramedullary cavity of the femoral diaphysis of the human body, and then the proximal prosthesis stem can be implanted into the intramedullary cavity of the femoral metaphysis of the human body, and the locking rod penetrates into the distal prosthesis stem from the installation channel. The locking rod can connect the proximal prosthesis stem and the distal prosthesis stem to form a whole. Since the distal prosthesis stem is provided with an anti-retreat structure, the problem of loosening of the femoral stem can be avoided. On the other hand, since the locking rod can abut against the crimping surface, when the locking rod gradually moves towards the distal end of the femur, the distal prosthesis stem remains fixed to the distal end of the femur under the action of the anti-retreat structure, and the locking rod can drive the proximal prosthesis stem and the femoral metaphysis of the human body to move towards the direction of the femoral diaphysis of the human body under the action of pressure, so as to press the osteotomy surface of the femoral metaphysis of the human body and the osteotomy surface of the femoral diaphysis of the human body. Thereby increasing the contact area between the two osteotomy surfaces, which is beneficial to improving the stability and healing speed after the femoral stem is implanted.

[0009] In some embodiments, a transverse hole is provided in the distal prosthesis stem, the transverse hole penetrates the distal prosthesis stem along a direction orthogonal to the length direction of the distal prosthesis stem, the anti-retreat structure is an anti-retreat nail, and the anti-retreat nail penetrates and protrudes from the transverse hole; and / or, vertical ridges are provided on the outer wall of the distal prosthesis stem, and the vertical ridges extend along the length direction of the distal prosthesis stem; and / or, the anti-retreat structure is an annular protrusion provided on the outer wall of the distal prosthesis stem, and the annular protrusion is arranged around the circumference of the distal prosthesis stem.

[0010] In some embodiments, the distal prosthesis stem is provided with a threaded hole, the locking rod includes a threaded section, and the threaded section is in threaded cooperation with the threaded hole. When the locking rod moves axially through threaded connection, the distal prosthesis stem and the proximal prosthesis stem can be connected.

[0011] In some embodiments, there are multiple card slots and multiple inserts. The multiple card slots are arranged at intervals along the circumferential direction of the distal prosthesis stem on the side wall of the distal prosthesis stem. The multiple inserts are arranged at intervals around the circumferential direction of the installation channel and all extend along the length direction of the installation channel. The multiple inserts are snap-connected to the multiple card slots in one-to-one correspondence; and / or, the mating length between the insert and the card slot is L, where 5 mm ≤ L ≤ 10 mm.

[0012] In some embodiments, an expansion channel is provided in the distal prosthesis stem, and the locking rod passes through the expansion channel and can press the distal prosthesis stem to deform radially towards the expansion channel.

[0013] In some embodiments, the distal prosthesis stem includes a connection section and an expansion section. The expansion section includes multiple expansion sheets. One end of the connection section is detachably connected to the proximal prosthesis stem, and the other end of the connection section is connected to the multiple expansion sheets. The multiple expansion sheets are arranged around the circumferential direction of the connection section to enclose the expansion channel, and the locking rod can press the expansion sheets to move radially towards the expansion channel.

[0014] In some embodiments, a tapered thread surface is provided in the expansion channel. The inner diameter of the tapered thread surface gradually decreases in the direction away from the proximal prosthesis stem. At least part of the tapered thread surface is formed on the inner wall of the expansion sheet. The locking rod includes a threaded section, and the threaded section is in threaded cooperation with the tapered thread surface.

[0015] In some embodiments, the proximal prosthesis stem includes a proximal end portion and a neck. The neck is connected to the proximal end portion. The installation channel and the proximal end portion are both provided on the proximal end portion. In the direction from the proximal end to the distal end of the proximal end portion, the thickness of the proximal end portion gradually decreases.

[0016] In some embodiments, the proximal end portion has a first side surface and a second side surface that are arranged opposite to each other in the thickness direction. The included angle between the first side surface and the second side surface is A, where 1° ≤ A ≤ 5°; and / or, the thickness of the proximal end of the proximal end portion is B, where 11 mm ≤ B ≤ 24 mm; and / or, the installation channel includes a first hole section, a second hole section, and a third hole section that communicate with each other. The first hole section, the second hole section, and the third hole section are arranged in sequence in the direction from the proximal end to the distal end of the proximal end portion. The inner diameter of the second hole section is smaller than the inner diameters of the first hole section and the third hole section. The crimping surface is formed at one end of the first hole section adjacent to the second hole section, and the distal prosthesis stem is inserted into the third hole section.

[0017] In a second aspect, a hip joint prosthesis according to another embodiment of the present invention includes the femoral stem described in the first aspect of the present invention.

[0018] Among them, for the hip joint prosthesis according to an embodiment of the present invention, when installing the femoral stem, the distal prosthesis stem can be first implanted into the intramedullary cavity of the femoral diaphysis of the human body, and then the proximal prosthesis stem can be implanted into the intramedullary cavity of the femoral metaphysis of the human body. The locking rod passes through the installation channel and penetrates into the distal prosthesis stem. The locking rod can connect the proximal prosthesis stem and the distal prosthesis stem to form an integral body. Since the distal prosthesis stem is provided with an anti-retreat structure, the problem of loosening of the femoral stem can be avoided. On the other hand, since the locking rod can abut against the crimping surface, when the locking rod gradually moves towards the direction of the distal femur, the distal prosthesis stem is fixed to the distal femur under the action of the anti-retreat structure, and the locking rod can drive the proximal prosthesis stem and the femoral metaphysis of the human body to move towards the direction of the femoral diaphysis of the human body under the action of pressure, so as to pressurize the osteotomy surface of the femoral metaphysis of the human body and the osteotomy surface of the femoral diaphysis of the human body. Thereby increasing the contact area between the two osteotomy surfaces, which is beneficial to improving the stability and healing speed after the femoral stem is implanted.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The structure is simple and reasonable. By setting an anti-retreat structure on the distal prosthesis stem to improve the bonding force between the distal prosthesis stem and the proximal prosthesis stem, and by setting the pressurization of the promoting end face to achieve the rapid healing of the bone block of the femur after resection, enhancing the stability of the femoral stem after replacement; by setting the mutually cooperating inserts and card slots between the distal prosthesis stem and the proximal prosthesis stem to improve the anti-rotation effect of the femoral stem, thereby further enhancing the pressurization effect between the two. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is an exploded view of the femoral stem according to an embodiment of the present invention.

[0021] Figure 2 is a schematic diagram of the femoral stem according to an embodiment of the present invention.

[0022] Figure 3 is a cross-sectional view of the installation of the femoral stem according to an embodiment of the present invention and the human femur.

[0023] Figure 4 is a cross-sectional view of the installation of the femoral stem (removing the locking rod) according to an embodiment of the present invention and the human femur.

[0024] Figure 5 is a schematic diagram of the proximal prosthesis stem of the femoral stem according to an embodiment of the present invention.

[0025] Figure 6 is a schematic diagram of the distal prosthesis stem of the femoral stem according to an embodiment of the present invention.

[0026] Figure 7 is a schematic diagram of the locking rod of the distal prosthesis stem of the femoral stem according to an embodiment of the present invention.

[0027] Figure 8 It is a schematic diagram of the femoral stem of another embodiment of the present invention.

[0028] Figure 9 It is a cross-sectional view of the femoral stem of another embodiment of the present invention.

[0029] Figure 10 It is a side view of the proximal prosthesis stem of the femoral stem of another embodiment of the present invention.

[0030] Reference numerals: 1. Proximal prosthesis stem; 11. Proximal end; 111. Installation channel; 1111. First hole section; 1112. Second hole section; 113. Third hole section; 112. Crimping surface; 113. Insert; 12. Neck; 13. Anti-rotation part; 2. Distal prosthesis stem; 21. Connection section; 211. Card slot; 22. Expansion section; 221. Expansion piece; 23. Expansion channel; 24. Transverse hole; 25. Vertical ridge; 26. Annular protrusion; 27. Gap groove; 3. Locking rod; 31. Thread section; 32. Crimping section; 4. Anti-retreat nail; 5. Human femoral shaft; 6. Human femoral metaphysis. Detailed implementation manners

[0031] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0032] Below, refer to the attached Figures 1 to 10 Describe the femoral stem and hip joint prosthesis according to the embodiments of the present invention.

[0033] As Figures 1 to 4 shown, the femoral stem of the embodiment of the present invention includes: a proximal prosthesis stem 1, a distal prosthesis stem 2, and a locking rod 3. An installation channel 111 is provided in the proximal prosthesis stem 1. The installation channel 111 penetrates the proximal prosthesis stem 1 in the direction from the proximal end to the distal end of the proximal prosthesis stem 1, and a crimping surface 112 is provided on the proximal prosthesis stem 1.

[0034] The distal prosthesis stem 2 is detachably installed at the distal end of the proximal prosthesis stem 1. The distal prosthesis stem 2 is provided with an anti-retreat structure. One end of the locking rod 3 passes through the installation channel 111 and abuts against the crimping surface 112, and the other end of the locking rod 3 is connected to the distal prosthesis stem 2.

[0035] According to the femoral stem of an embodiment of the present invention, when installing the femoral stem, the distal prosthesis stem 2 can be first implanted into the medullary cavity of the femoral diaphysis 5 of the human body, and then the proximal prosthesis stem 1 can be implanted into the medullary cavity of the femoral metaphysis 6 of the human body. The locking rod 3 passes through the installation channel 111 and penetrates into the distal prosthesis stem 2. The locking rod 3 can connect the proximal prosthesis stem 1 and the distal prosthesis stem 2 to form an integral body. Since the distal prosthesis stem 2 is provided with an anti-retreat structure, the problem of loosening of the femoral stem can be avoided. On the other hand, since the locking rod 3 can abut against the crimping surface 112, when the locking rod 3 gradually moves towards the distal femur direction, the distal prosthesis stem 2 remains fixed to the distal femur under the action of the anti-retreat structure. The locking rod 3 can drive the proximal prosthesis stem 1 and the femoral metaphysis 6 of the human body to move towards the femoral diaphysis 5 of the human body under the action of pressure, so as to press the osteotomy surfaces of the femoral metaphysis 6 of the human body and the femoral diaphysis 5 of the human body. Thereby increasing the contact area between the two osteotomy surfaces, which is beneficial to improving the stability and healing speed after the femoral stem is implanted.

[0036] It should be noted that the usage scenario of the femoral stem of the embodiment of the present invention is that the femur of the patient has been osteotomized at a certain position below the lesser trochanter of the femur, that is, the femoral metaphysis 6 of the human body and the femoral diaphysis 5 of the human body are separated by a transverse osteotomy. First, the doctor implants the distal prosthesis stem 2 into the medullary cavity of the femoral diaphysis 5 of the human body, implants the proximal prosthesis stem 1 into the femoral metaphysis 6 of the human body, then docks the truncated femoral metaphysis 6 of the human body and the femoral diaphysis 5 of the human body together, and finally passes the locking rod 3 through the installation channel 111 of the proximal prosthesis stem 1 and moves it downward into the distal prosthesis stem 2. Due to the arrangement of the anti-retreat structure, the problem of loosening of the distal prosthesis stem 2 from the femoral diaphysis 5 of the human body is avoided, and at the same time, the pressing effect can be ensured.

[0037] Optionally, the distal prosthesis stem 2 is provided with a threaded hole, and the locking rod 3 includes a threaded section 31, and the threaded section 31 is in threaded cooperation with the threaded hole. It can be understood that the locking rod 3 is connected to the distal prosthesis stem 2 through the threaded section 32 to ensure the reliability of the connection between the two. When the locking rod 3 is screwed, due to the existence of the anti-retreat structure, there is no movement between the distal prosthesis stem 2 and the femoral diaphysis 5 of the human body. Under the blocking action of the crimping surface 112, the locking rod 3 will drive the proximal prosthesis stem 1 to move downward, and the proximal prosthesis stem 1 drives the femoral metaphysis 6 of the human body cooperating with it to move downward, so as to achieve the effect of pressing the femoral metaphysis 6 of the human body onto the femoral diaphysis 5 of the human body, so as to promote the rapid healing of the osteotomy surfaces of the two femurs.

[0038] In some embodiments, as Figures 1 to 4 shown, an expansion channel 23 is provided in the distal prosthesis stem 2, and the locking rod 3 penetrates through the expansion channel 23 and can compress the distal prosthesis stem 2 to deform radially towards the expansion channel 23. It can be understood that the distal prosthesis stem 2 deforms radially towards the expansion channel 23 to further improve the reliability of the connection between the distal prosthesis stem 2 and the distal femur.

[0039] When the locking rod 3 penetrates into the expansion channel 23, the distal prosthetic stem 2 can undergo radial deformation under the extrusion of the locking rod 3, so that the outer wall surface of the distal prosthetic stem 2 is closely attached to the medullary cavity of the human femoral shaft 5, avoiding the problem of loosening between the distal prosthetic stem 2 and the human femoral shaft 5.

[0040] Optionally, as Figure 4 shown, the distal prosthetic stem 2 includes a connecting section 21 and an expansion section 22. The expansion section 22 includes a plurality of expansion sheets 221. One end of the connecting section 21 is detachably connected to the proximal prosthetic stem 1, and the other end of the connecting section 21 is connected to the plurality of expansion sheets 221. The plurality of expansion sheets 221 are arranged circumferentially around the connecting section 21 to enclose an expansion channel 23. A gap groove 27 is provided between two adjacent expansion sheets 221. The locking rod 3 can press the expansion sheets 221 to move radially toward the expansion channel 23. It can be understood that when the locking rod 3 is screwed downward, the locking rod 3 can simultaneously squeeze a plurality of expansion sheets 221, and the plurality of expansion sheets 221 can synchronously deform toward the direction of the medullary cavity wall of the human femoral shaft 5, so that the distal prosthetic stem 2 is in closer contact with the medullary cavity of the human femoral shaft 5 and the fixation is more stable.

[0041] Optionally, the expansion channel 23 has a tapered thread surface, and the inner diameter of the tapered thread surface gradually decreases in the direction away from the proximal prosthetic stem 1. At least part of the tapered thread surface is formed on the inner wall of the expansion sheet 221. The locking rod 3 includes a threaded section 31, and the threaded section 31 is in threaded cooperation with the tapered thread surface. It can be understood that when the threaded section 31 is gradually screwed downward, since the inner diameter of the tapered thread surface gradually decreases in the direction away from the proximal prosthetic stem 1, the expansion sheet 221 can be gradually pushed to deform toward the direction of the medullary cavity wall of the human femoral shaft 5, so that the distal prosthetic stem 2 is in closer contact with the medullary cavity of the human femoral shaft 5 and the fixation is more stable.

[0042] And because the locking rod 3 is in threaded cooperation with the expansion channel 23, the probability of loosening between the locking rod 3 and the distal prosthetic stem 2 can be reduced, and the firmness of the connection between the locking rod 3 and the distal prosthetic stem 2 can be improved.

[0043] In other examples, the lower end of the locking rod 3 is a pin structure, and the pin has a certain taper. When the locking rod 3 gradually penetrates downward through the expansion channel 23, the tapered pin can gradually squeeze the expansion sheet 221, so that the expansion sheet 221 deforms toward the direction of the medullary cavity wall of the human femoral shaft 5.

[0044] Such as Figure 1 and Figure 3As shown, when installing the femoral stem, the distal prosthesis stem 2 can be first implanted into the medullary cavity of the human femoral diaphysis, and then the proximal prosthesis stem 1 can be implanted into the medullary cavity of the metaphysis of the human femoral diaphysis. The locking rod 3 penetrates through the installation channel 111 into the expansion channel 23. Since the locking rod 3 can press the expansion piece 221 to deform in the direction away from the expansion channel 23, the distal prosthesis stem 2 can be firmly fixed in the medullary cavity of the human femoral diaphysis. Since the locking rod 3 can abut against the crimping surface 112, when the locking rod 3 gradually moves towards the distal femur, the locking rod 3 can drive the proximal prosthesis stem 1 and the metaphysis of the human femoral diaphysis 6 to move towards the human femoral diaphysis 5 under the action of pressure, so as to pressurize the osteotomy surfaces of the metaphysis of the human femoral diaphysis 6 and the human femoral diaphysis 5, thereby increasing the contact area between the two osteotomy surfaces, which is beneficial to improving the stability and healing speed after the femoral stem is implanted.

[0045] Optionally, as Figure 3 shown, one end of the distal prosthesis stem 2 is inserted into the installation channel 111. An insertion piece 113 is provided on one of the outer wall of the distal prosthesis stem 2 and the proximal prosthesis stem 1, and a card slot 211 is provided on the other. The insertion piece 113 is engaged with the card slot 211. It can be understood that the connecting section 21 is inserted and fixed with the installation channel 111, so that the doctor can pre-fix the proximal prosthesis stem 1 and the distal prosthesis stem 2 before installing the locking rod 3. After the connecting section 21 is inserted and fixed with the installation channel 111, the installation channel 111 and the expansion channel 23 are on the same axis, which is convenient for the installation work of the locking rod 3.

[0046] Since an insertion piece 113 is provided on one of the outer wall of the connecting section 21 and the proximal prosthesis stem 1, and a card slot 211 is provided on the other, and the insertion piece 113 is engaged with the card slot 211, the problem of relative rotation between the proximal prosthesis stem 1 and the distal prosthesis stem 2 can be avoided, the anti-rotation effect of the femoral stem can be improved, and further the pressurization effect between the two can be enhanced.

[0047] In one example, both the card slot 211 and the insertion piece 113 are multiple. The multiple card slots 211 are arranged at intervals along the circumferential direction of the distal prosthesis stem 2 on the side wall of the distal prosthesis stem 2. The multiple insertion pieces 113 are arranged at intervals around the circumferential direction of the installation channel 111 and all extend along the length direction of the installation channel 111. The multiple insertion pieces 113 are engaged with the multiple card slots 211 one by one. Thus, different insertion pieces 113 can be engaged with card slots 211 at different angles, so that the proximal prosthesis stem 1 and the distal prosthesis stem 2 have different installation angles. And since the multiple insertion pieces 113 are engaged with the multiple card slots 211 one by one, the firmness of the connection between the proximal prosthesis stem 1 and the distal prosthesis stem 2 can be ensured, and the anti-rotation effect of the femoral stem is further improved.

[0048] For example, the insert piece 113 can be arranged within the installation channel 111. As another example, the insert piece 113 can extend downward in a direction away from the installation channel 111. The present application does not limit the specific position of the insert piece 113.

[0049] Optionally, the mating length of the insert piece 113 and the card slot 211 is L, where 5 mm ≤ L ≤ 10 mm. For example, the mating length L of the insert piece 113 and the card slot 211 is 5 mm, 7 mm, 9 mm, or 10 mm. Thereby, the structural strength after the assembly of the insert piece 113 can be improved, and the problem that the insert piece 113 is deformed due to excessive torsional force between the proximal prosthesis stem 1 and the distal prosthesis stem 2 can be avoided.

[0050] In some embodiments, the proximal prosthesis stem 1 includes a proximal end portion 11 and a neck portion 12. The neck portion 12 is connected to the proximal end portion 11. The installation channel 111 and the proximal end portion 11 are both provided on the proximal end portion 11. In the direction from the proximal end (upper end) to the distal end (lower end) of the proximal end portion 11, the thickness of the proximal end portion 11 gradually decreases.

[0051] It can be understood that the proximal end portion 11 has a certain draft angle, that is, the thickness of the proximal end (upper end) of the proximal end portion 11 is larger, and the thickness of the distal end (lower end) of the proximal end portion 11 is smaller, so that the proximal end portion 11 has a certain taper. Therefore, when the proximal end portion 11 moves downward, due to the certain taper of the proximal end portion 11 itself, a downward component force can be provided to the metaphysis 6 of the human femoral shaft, so as to drive the metaphysis 6 of the human femoral shaft to move downward and press against the human femoral shaft 5. On the other hand, the proximal end portion 11 with a certain taper is more matched with the medullary cavity of the human femur, which is beneficial to improving the stability after the implantation of the femoral stem.

[0052] For example, the cross-section of the proximal end portion 11 can be circular or rectangular. That is, the outer shape of the proximal end portion 11 is generally a tapered cylindrical structure or can also be a tapered cuboid structure.

[0053] Optionally, as Figure 10 shown, the proximal end portion 11 has a first side surface and a second side surface that are oppositely arranged along its thickness direction. The included angle between the first side surface and the second side surface is A, where 1° ≤ A ≤ 5°. It can be understood that the draft angle of the proximal end portion 11 is 1° - 5°. For example, the included angle A between the first side surface and the second side surface is 1°, 3°, or 5°. The inventors of the present application have found through research that when the draft angle A of the proximal end portion 11 satisfies the above range, the proximal prosthesis stem 1 can be more matched with the shape of the medullary cavity of the femoral bone of patients with congenital hip dislocation, and can provide a downward pressure to the metaphysis 6 of the human femoral shaft, which is beneficial to improving the healing speed and quality after the implantation of the femoral stem.

[0054] In an example, as Figure 2As shown, the proximal prosthesis stem 1 further includes an anti-rotation portion 13. The anti-rotation portion 13 is disposed inside the proximal end portion 11 and is connected to the proximal end portion 11 and the neck portion 12. In the direction from the distal end of the femoral stem to the proximal end of the proximal end portion 11, the width between the inner side surface of the anti-rotation portion 13 and the outer side surface of the proximal end portion 11 gradually increases. It can be understood that in the projection plane parallel to the human body coronal plane, the anti-rotation portion 13 is generally triangular. Since the anti-rotation portion 13 is located in the femoral medullary cavity of the metaphysis 6 of the human femoral shaft, the anti-rotation performance of the femoral stem can be greatly improved, ensuring the stability of the femoral stem after implantation.

[0055] Optionally, as Figure 10 shown, the thickness of the proximal end of the proximal end portion 11 is B, where 11 mm ≤ B ≤ 24 mm. For example, the thickness B of the proximal end of the proximal end portion 11 can be 11 mm, 14 mm, 17 mm, 20 mm, 24 mm. The inventors of the present application found through research that the medullary cavity size of patients with congenital hip dislocation is much thinner than that of normal people. Therefore, the size of the proximal prosthesis stem 1 is also relatively small. The size of the uppermost end of the proximal prosthesis stem 1 (i.e., the thickness B of the proximal end of the proximal end portion 11) in the range of 11 mm - 24 mm can meet the usage requirements of most patients and has a good implantation effect.

[0056] In some embodiments, as Figure 3 shown, the installation channel 111 includes a first hole section 1111, a second hole section 1112, and a third hole section 113 that are interconnected. The first hole section 1111, the second hole section 1112, and the third hole section 113 are arranged in sequence in the direction from the proximal end of the proximal end portion 11 to the distal end of the proximal end portion 11. The inner diameter of the second hole section 1112 is smaller than the inner diameters of the first hole section 1111 and the third hole section 113. The crimping surface 112 is formed at one end of the first hole section 1111 adjacent to the second hole section 1112. The distal prosthesis stem 2 is inserted into the third hole section 113. It can be understood that the first hole section 1111, the second hole section 1112, and the third hole section 113 are connected in sequence and coaxially arranged in the up-down direction. Since the inner diameter of the second hole section 1112 is smaller than the inner diameter of the first hole section 1111, a stepped surface can be formed at the connection position between the first hole section 1111 and the second hole section 1112, and the stepped surface is the crimping surface 112.

[0057] Specifically, as Figure 3 shown, the locking rod 3 has a crimping section 32. The crimping section 32 is disposed at the upper end of the threaded section 31. The outer diameter of the crimping section 32 is larger than the inner diameter of the second hole section 1112, thereby ensuring that the crimping section 32 and the crimping surface 112 can be in mutual contact.

[0058] In addition, as Figure 3As shown, since the inner diameter of the second hole section 1112 is smaller than that of the third hole section 113, a stepped surface can be formed at the positions of the second hole section 1112 and the third hole section 113. The upper end of the distal prosthesis stem 2 can abut against this stepped surface, thereby limiting the axial direction of the proximal prosthesis stem 1.

[0059] In some embodiments, as Figure 8 and Figure 9 shown, a transverse hole 24 is provided in the distal prosthesis stem 2, and the transverse hole 24 penetrates the distal prosthesis stem 2 along a direction orthogonal to the length direction of the distal prosthesis stem 2. The anti-withdrawal structure is an anti-withdrawal nail 4, and the anti-withdrawal nail 4 penetrates and protrudes from the transverse hole 24. It can be understood that the extending direction of the transverse hole 24 is orthogonal to the length direction of the distal prosthesis stem 2. Since the anti-withdrawal nail 4 penetrates and protrudes from the transverse hole 24 along the extending direction of the transverse hole 24, the problem of the distal prosthesis stem 2 being withdrawn from the femoral medullary cavity of the human body in the vertical direction can be greatly reduced, and the anti-pull-out performance of the femoral stem can be improved.

[0060] Optionally, there are multiple anti-withdrawal nails 4, and the multiple anti-withdrawal nails 4 are arranged at intervals along the length direction of the distal prosthesis stem 2 to further improve the anti-pull-out performance of the femoral stem.

[0061] For example, the anti-withdrawal nail 4 can be a dowel pin or a threaded part, and the present application does not limit this.

[0062] Optionally, vertical ridges 25 are provided on the outer wall of the distal prosthesis stem 2, and the vertical ridges 25 extend along the length direction of the distal prosthesis stem 2. There can be multiple vertical ridges 25, and the multiple vertical ridges 25 are arranged at intervals along the circumferential direction of the distal prosthesis stem 2. The inventors of the present application have found through research that by providing the vertical ridges 25 on the outer wall of the distal prosthesis stem 2, the anti-pull-out and anti-torsion performance of the distal prosthesis stem 2 can be improved, and the stability of the distal prosthesis stem 2 after implantation is better.

[0063] Furthermore, the protruding height of the vertical ridge 25 is between 0.05 mm and 0.75 mm. For example, the protruding height of the vertical ridge 25 is 0.05 mm, 0.2 mm, 0.4 mm, 0.7 mm, 0.75 mm. The inventors of the present application have found through research that when the height of the vertical ridge 25 is less than 0.05 mm, it is not sufficient to ensure the anti-pull-out and anti-torsion effects of the distal prosthesis stem 2, resulting in the problem that the distal prosthesis stem 2 is prone to looseness after implantation. When the height of the vertical ridge 25 is greater than 0.75 mm, stress concentration is likely to occur, and thus the femoral medullary cavity is prone to burst when the distal prosthesis stem 2 is implanted. Therefore, in the femoral stem of the embodiment of the present invention, the protruding height of the vertical ridge 25 is set between 0.05 mm and 0.75 mm, which can not only ensure that the distal prosthesis stem 2 has good anti-pull-out and anti-torsion performance, but also is not prone to the problem of femoral medullary cavity burst during implantation, and the use effect is good.

[0064] Optionally, the anti-retreat structure is an annular protrusion 26 provided on the outer wall of the distal prosthesis stem 2, and the annular protrusion 26 is arranged circumferentially around the distal prosthesis stem 2. For example, there are multiple annular protrusions 26, and the multiple annular protrusions 26 are arranged at intervals along the length direction of the distal prosthesis stem 2. For example, the annular protrusion 26 is barbed, that is, the annular protrusion 26 extends obliquely upward in a direction away from the distal prosthesis stem 2 to further improve the anti-pull-out effect of the distal prosthesis stem 2.

[0065] The femoral stem according to another embodiment of the present invention includes the femoral stem of the embodiment of the present invention.

[0066] For the hip joint prosthesis according to the embodiment of the present invention, when installing the femoral stem, the distal prosthesis stem 2 can be first implanted into the medullary cavity of the femoral shaft 5 of the human body, and then the proximal prosthesis stem 1 can be implanted into the medullary cavity of the metaphysis 6 of the femoral shaft of the human body. The locking rod 3 passes through the installation channel 111 and penetrates into the distal prosthesis stem 2 and is connected to the distal prosthesis stem 2. The anti-retreat structure can firmly fix the distal prosthesis stem 2 in the medullary cavity of the femoral shaft 5 of the human body. After the locking rod 3 is screwed, since the locking rod 3 can abut against the crimping surface 112, when the locking rod 3 gradually moves towards the direction of the distal femur, the locking rod 3 can drive the proximal prosthesis stem 1 and the metaphysis 6 of the femoral shaft of the human body to move towards the direction of the femoral shaft 5 of the human body under the action of pressure, so as to pressurize the osteotomy surfaces of the metaphysis 6 of the femoral shaft of the human body and the osteotomy surface of the femoral shaft 5 of the human body, thereby increasing the contact area between the two osteotomy surfaces, which is beneficial to improving the stability and healing speed after the femoral stem is implanted.

[0067] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0068] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0069] In the present invention, unless otherwise clearly specified or limited, terms such as "install", "connect", "link", "fix", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or capable of communicating with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is less than that of the second feature.

[0071] In the present invention, terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0072] Although the above embodiments have been shown and described, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made by those of ordinary skill in the art to the above embodiments are within the protection scope of the present invention.

Claims

1. A femoral stem, characterized in that, Comprising: A proximal prosthesis stem, an installation channel is provided in the proximal prosthesis stem, the installation channel penetrates the proximal prosthesis stem in the direction from the proximal end to the distal end of the proximal prosthesis stem, and a crimping surface is provided on the proximal prosthesis stem; A distal prosthesis stem, the distal prosthesis stem is detachably installed at the distal end of the proximal prosthesis stem, and the distal prosthesis stem is provided with an anti-retreat structure; One end of the distal prosthesis stem is inserted into the installation channel, a tab is provided on one of the outer wall of the distal prosthesis stem and the proximal prosthesis stem, and a slot is provided on the other, and the tab is snap-fitted with the slot; A locking rod, one end of the locking rod passes through the installation channel and abuts against the crimping surface, the other end of the locking rod is connected to the distal prosthesis stem, and the proximal prosthesis stem and the distal prosthesis stem are pressed and fitted together by the locking rod.

2. The femoral stem according to claim 1, wherein, A transverse hole is provided in the distal prosthesis stem, the transverse hole penetrates the distal prosthesis stem along a direction orthogonal to the length direction of the distal prosthesis stem, and the anti-retreat structure is an anti-retreat nail, and the anti-retreat nail penetrates and protrudes from the transverse hole; And / or, vertical ridges are provided on the outer wall of the distal prosthesis stem, and the vertical ridges extend along the length direction of the distal prosthesis stem.

3. The femoral stem according to claim 1, wherein The distal prosthesis stem is provided with a threaded hole, and the locking rod includes a threaded section, and the threaded section is in threaded cooperation with the threaded hole.

4. The femoral stem according to claim 1, characterized in that Both the slot and the tab are multiple, the multiple slots are arranged at intervals along the circumferential direction of the distal prosthesis stem on the side wall of the distal prosthesis stem, the multiple tabs are arranged at intervals around the circumferential direction of the installation channel, and all extend along the length direction of the installation channel, and the multiple tabs are snap-fitted with the multiple slots one by one; And / or, the mating length of the tab and the slot is L, where 5mm ≤ L ≤ 10mm.

5. The femoral stem according to claim 1, characterized in that, An expansion channel is provided in the distal prosthesis stem, and the locking rod passes through the expansion channel and can press the distal prosthesis stem to deform radially towards the expansion channel.

6. The femoral stem according to claim 5, characterized in that, The distal prosthesis stem includes a connecting section and an expansion section, the expansion section includes a plurality of expansion sheets, one end of the connecting section is detachably connected to the proximal prosthesis stem, the other end of the connecting section is axially connected to the plurality of expansion sheets, and the plurality of expansion sheets are arranged around the circumferential direction of the connecting section to enclose the expansion channel, and when the locking rod moves axially, it can press the expansion sheets to move radially towards the expansion channel.

7. The femoral stem according to claim 6, wherein A tapered thread surface is provided in the expansion channel, the inner diameter of the tapered thread surface gradually decreases in the direction away from the proximal prosthesis stem, at least part of the tapered thread surface is formed on the inner wall of the expansion sheet, and the locking rod includes a threaded section, and the threaded section is in threaded cooperation with the tapered thread surface.

8. The femoral stem according to claim 1, characterized in that, The proximal prosthesis stem includes a proximal end portion and a neck portion, the neck portion is connected to the proximal end portion, the installation channel and the proximal end portion are both provided on the proximal end portion, and in the direction from the proximal end to the distal end of the proximal end portion, the thickness of the proximal end portion gradually decreases.

9. The femoral stem according to claim 8, characterized in that, The proximal end portion has a first side surface and a second side surface arranged opposite to each other in the thickness direction thereof, and the included angle between the first side surface and the second side surface is A, where 1° ≤ A ≤ 5°; And / or, the thickness of the proximal end of the proximal portion is B, where 11 mm ≤ B ≤ 24 mm; And / or, the installation channel includes a first hole section, a second hole section, and a third hole section that communicate with each other. The first hole section, the second hole section, and the third hole section are arranged in sequence along the direction from the proximal end to the distal end of the proximal portion. The inner diameter of the second hole section is smaller than the inner diameters of the first hole section and the third hole section. The crimping surface is formed at one end of the first hole section adjacent to the second hole section, and the distal prosthesis stem is inserted into the third hole section.

10. A hip joint prosthesis, characterized in that, Comprising the femoral stem according to any one of claims 1-9.

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