Hip stem and hip replacement system

Abstract

The present invention provides a hip replacement stem and hip replacement system. The hip replacement stem comprises a stem body, comprising a proximal segment and a distal segment connected to the proximal segment, and having a proximal end and a distal end; a stem neck, obliquely disposed above and obliquely above the proximal end of the stem, with the base of the stem neck smoothly connected to the proximal end of the stem, and a tapered head disposed at the free end of the stem neck; and a protrusion, circumferentially disposed around the outer periphery of the proximal segment of the stem and the outer periphery of the connection between the stem and the stem neck; the protrusion having a proximal surface, an outer side surface, and a distal surface, each connected in sequence, the proximal and distal surfaces being respectively connected to the outer surface of the stem body; the proximal surface of the protrusion forming an angle of 83° to 85° with the axis of the stem body. The hip replacement stem has strong anti-sinking capability and a wide range of applications.

Description

Technical Field

[0001] The invention belongs to the field of medical devices and relates to a hip handle and a hip replacement system. Background Art

[0002] During hip surgery, the stem prosthesis is a key component that bears gravity. After implantation, the stem may sink due to gravity, stress, and other factors. In severe cases, revision surgery is required. Therefore, how to prevent the stem from sinking after implantation has become a key research topic for many people. Traditional stem designs use a proximal tapered design and spray coating on the surface to prevent postoperative sinking. The principle is that the cone is larger at the top and smaller at the bottom. The cone can make the stem contact with the medullary cavity closer during the sinking process, thereby preventing the continuation of sinking. However, this design cannot completely and effectively prevent sinking. As the bone becomes porous and the gap increases, sinking will still occur. Summary of the Invention

[0003] In view of the deficiencies in the prior art, the present invention aims to provide a hip stem and a hip replacement system, wherein the hip stem has a strong anti-sinking ability.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] One of the purposes of the present invention is to provide a hip handle comprising:

[0006] The handle body comprises a handle body proximal section and a handle body distal section connected to the handle body proximal section, and has a handle body proximal end and a handle body distal end, and is used for implantation into the medullary cavity;

[0007] A handle neck is obliquely arranged above the proximal end of the handle body, with the base of the handle neck smoothly connected to the proximal end of the handle body and a cone head provided at the free end of the handle neck; and

[0008] A protrusion is provided on the proximal end section of the handle body and / or the connection portion between the handle body and the handle neck; the protrusion has a proximal end surface, an outer side surface and a distal end surface connected in sequence, and the proximal end surface and the distal end surface are respectively connected to the outer surface of the handle body;

[0009] The proximal surface of the protrusion forms an angle of 83° to 85° with the axis of the handle body.

[0010] Furthermore, the protrusion is arranged around the proximal end section of the handle body and the outer circumference of the connection portion between the handle body and the handle neck.

[0011] Preferably, there are multiple protrusions, and the multiple protrusions are distributed in a stepped manner from the proximal end to the distal end.

[0012] Furthermore, the plurality of protrusions include a first protrusion and a second protrusion adjacent to each other and arranged from the proximal end to the distal end, and the lower end surface of the first protrusion is radially contracted relative to the upper end surface of the second protrusion.

[0013] Furthermore, the spacing between adjacent protrusions is 1.5-5.0 mm.

[0014] Furthermore, the distance between the outer side surface and the outer surface of the handle body is 0.4~0.8mm.

[0015] Furthermore, the handle body is conical, and the cross-sectional area gradually decreases from the proximal end to the distal end of the handle body, and the taper of the handle body is 4°~6°.

[0016] Furthermore, the proximal end section of the handle body is provided with a plasma coating.

[0017] Preferably, the plasma coating has a thickness of 0.15-0.30 mm and a porosity of 20%-30%.

[0018] Furthermore, a ridge is provided on the distal end section of the handle body from the proximal end to the distal end.

[0019] Furthermore, the central axis of the handle neck intersects with the central axis of the handle body, and the angle formed by the central axis of the handle neck and the central axis of the handle body is 40°~50°.

[0020] Preferably, the length of the handle neck is 47-49 mm, the length of the handle body is 128-132 mm, and the length of the proximal section of the handle body is 34-36 mm.

[0021] A second object of the present invention is to provide a hip replacement system comprising the hip stem as described above.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The hip stem and hip replacement system provided by the present invention are provided with a protrusion on the proximal end section of the handle body of the hip stem and / or the connection part between the handle body and the handle neck. The proximal end surface of the protrusion forms an angle of 83°~85° with the axis of the handle body, which reduces the shaking of the handle body in the medullary cavity, thereby reducing the scraping and wear of the handle body coating on the medullary cavity bone, so that the femoral medullary cavity has sufficient bone to resist the sinking of the hip stem, and ultimately improves the anti-sinking ability of the hip stem; in addition, the protrusions are arranged around the outer circumference and distributed in a stepped manner, and the spacing between the protrusions is reasonably set, further improving the anti-sinking ability of the hip stem; and because the handle body of the hip stem is provided with a ridge extending from the proximal end to the distal end, it can prevent the handle body from deflecting in the medullary cavity; finally, the handle neck and handle body of the hip stem are reasonably set and have a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a stereoscopic view of a hip handle provided by one embodiment of the invention.

[0025] Figure 2 It is a front view of a hip handle provided by one embodiment of the invention.

[0026] Figure 3 yes Figure 2 Magnified view of section I.

[0027] Figure 4 yes Figure 2 Middle AA section view.

[0028] in:

[0029] 1. Hip handle first;

[0030] 110, handle; 111, handle proximal end; 112, handle proximal segment; 113, handle distal end; 114, handle distal segment; 115, handle axis;

[0031] 120, handle neck; 121, connecting portion; 122, cone head; 123, handle neck axis;

[0032] 130, convex; 131, proximal surface; 132, lateral surface; 133, distal surface;

[0033] 140, ridge. DETAILED DESCRIPTION

[0034] The invention will be described in further detail below with reference to the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0035] It should be understood that terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or other elements or combinations thereof.

[0036] The "proximal end", "distal end", "proximal segment", "distal segment", "proximal surface 131" and "distal surface" mentioned in the present invention are distinguished according to the distance between the hip stem and the heart after the hip stem is implanted into the medullary cavity. "Proximal end", "proximal segment" and "proximal surface" refer to the end, a segment or a surface that is closer to the heart after the hip stem is implanted into the medullary cavity, and "distal end", "distal segment" and "distal surface" refer to the end, a segment or a surface that is farther from the heart after the hip stem is implanted into the medullary cavity.

[0037] In order to solve the technical problem that the anti-sinking ability of the hip stem 1 in the prior art is not high enough after being implanted into the medullary cavity, the present invention provides a hip stem 1 and a hip replacement system including the hip stem 1. The hip stem 1 includes:

[0038] The handle body 110 includes a handle body proximal section 112 and a handle body distal section 114 connected to the handle body proximal section 112, and has a handle body proximal end 111 and a handle body distal end 113, and is used for implantation into the medullary cavity;

[0039] A handle neck is obliquely arranged above the proximal end 111 of the handle body. The base of the handle neck 120 is smoothly connected to the proximal end 111 of the handle body. A cone head 122 is provided at the free end of the handle neck 120; and

[0040] A protrusion 130 is provided on the periphery of the proximal end section 112 of the handle body and / or on the connecting portion 121 between the handle body 110 and the handle neck 120. The protrusion 130 has a proximal end surface 131, an outer side surface 132, and a distal end surface 133 connected in sequence. The proximal end surface 131 and the distal end surface 133 are respectively connected to the outer surface of the handle body 110;

[0041] The proximal end surface 131 of the protrusion 130 forms an angle of 83° to 85° with the handle body axis 115 .

[0042] Since the proximal end section 112 of the handle body of the hip stem 1 and / or the connecting portion 121 between the handle body 110 and the handle neck 120 are provided with a protrusion 130, the proximal surface 131 of the protrusion 130 forms an angle of 83°~85° with the axis of the handle body 110, which can reduce the shaking of the handle body 110 in the medullary cavity, thereby reducing the scraping and wear of the coating of the handle body 110 on the medullary cavity bone, so that the femoral medullary cavity has sufficient bone to resist the sinking of the hip stem 1, and ultimately improve the anti-sinking ability of the hip stem 1.

[0043] In order to further improve the anti-sinking ability of the hip handle 1, the protrusion 130 is arranged around the outer periphery of the proximal end section 112 of the handle body and the connecting portion 121 of the handle body 110 and the handle neck 120; and a plurality of protrusions 130 are provided on the proximal end section 112 of the handle body and the connecting portion 121 of the handle body 110 and the handle neck 120, and the plurality of protrusions 130 are distributed in a stepped manner from the proximal end to the distal end.

[0044] Preferably, the multiple protrusions 130 include a first protrusion 130 and a second protrusion 130 adjacent to each other from the proximal end to the distal end, and the distal surface 133 of the first protrusion 130 is radially contracted relative to the proximal surface 131 of the second protrusion 130, that is, the radial dimension of the distal surface 133 of the first protrusion 130 is smaller than the radial dimension of the proximal surface 131 of the second protrusion 130.

[0045] Preferably, the distal end surface 133 of the protrusion 130 is an arc surface to facilitate processing and ensure the strength of the protrusion 130 .

[0046] Preferably, the distance between the outer side surface 132 and the outer surface of the handle body 110 is 0.4-0.8 mm, such as 0.5 mm, 0.6 mm or 0.7 mm, that is, the height of the protrusion 130 is 0.4-0.8 mm.

[0047] The protrusion 130 structure described above helps to further ensure the anti-sinking capability of the hip handle 1 .

[0048] Preferably, the spacing between adjacent protrusions 130 is 1.5-5.0 mm. Within this spacing range, both the anti-sinking effect and the excellent mechanical properties of the hip handle 1 can be achieved.

[0049] In order to further improve the anti-sinking ability of the hip handle 1, the handle body 110 is set to be conical, and the cross-sectional area gradually decreases from the proximal end 111 to the distal end 113 of the handle body. The taper of the handle body 110 is 4°~6°, such as 4.5°, 5° or 5.5°.

[0050] In order to facilitate bone ingrowth of the hip stem 1, improve the fixation effect between the hip stem 1 and the femur, and prevent the hip stem 1 from sinking, the proximal end section 112 of the stem body is provided with a plasma spray coating. The plasma spray coating can be a biocompatible material commonly used in the art that is conducive to bone ingrowth, such as a pure titanium coating, a hydroxyapatite coating, etc. The preferred coating thickness is 0.15~0.30mm, such as 0.18mm, 0.20mm or 0.25mm, and the porosity of the coating is 20%~30%, such as 22%, 25%, 28% or 29%.

[0051] Ridges 140 are provided along the midsection and distal section 114 of the handle body 110 from proximal to distal. The ridges 140 effectively prevent prosthesis rotation and ensure the central positioning of the hip stem 1 within the medullary cavity. The number of ridges 140 is preferably 4-12, such as 6, 7, 9, or 10, with 8 being most preferred. Furthermore, multiple ridges 140 are preferably evenly distributed along the midsection and distal section 114 of the handle body 110.

[0052] The central axis of the handle neck 120 intersects with the central axis of the handle body 110, and the angle β formed by the central axis of the handle neck 120 and the central axis of the handle body 110 is 40°~50°, such as 42°, 45°, 48° or 49°, so as to be suitable for different patients.

[0053] In order to further expand the application scope of the hip handle 1, the length of the handle neck 120 is 47~49 mm, the length of the handle body 110 is 128~132 mm, and the length of the proximal section 112 of the handle body is 34~36 mm.

[0054] The handle body 110 and the handle neck 120 are integrally formed.

[0055] The distal end 113 of the handle is provided with a rounded structure.

[0056] In addition, this embodiment also provides a hip replacement system, which includes the hip handle 1 as described above. The hip replacement system may also include a ball head, an acetabular cup, etc. The acetabular cup may be a single cup or double cup type.

[0057] The method of using the femoral stem provided in this embodiment is as follows: the stem body 110 is implanted into the patient's medullary cavity. Since the base of the stem neck 120 is smoothly connected to the proximal end 111 of the stem body, the connecting portion 121 formed by the base of the stem neck 120 and the proximal end 111 of the stem body protrudes from the outer surface of the stem body 110, so it is more firmly combined with the medullary cavity and can avoid shaking. At the same time, the proximal end surface 131 of the protrusion 130 is at an angle of 83~85° to the axis of the stem body 110. Within this angle range, the protrusion 130 can reduce the shaking of the stem body 110 in the medullary cavity, thereby reducing the scraping and wear of the coating of the stem body 110 on the medullary cavity bone, so that the femoral medullary cavity has sufficient bone to resist the sinking of the hip stem 1, and ultimately improve the anti-sinking ability of the hip stem 1.

[0058] Example 1

[0059] A hip replacement system includes a hip handle 1, wherein the hip handle 1 includes:

[0060] The handle body 110 is composed of a handle body proximal section 112, a handle body middle section 110 and a handle body distal section 114 connected in sequence, and has a handle body proximal end 111 and a handle body distal end 113, and is used for implantation in the medullary cavity;

[0061] The handle body 110 is conical, and the cross-sectional area gradually decreases from the proximal end 111 to the distal end 113 of the handle body. The taper of the handle body 110 is 5°.

[0062] The length of the handle body 110 is 130 mm, and the length of the handle body proximal end section 112 is 35 mm.

[0063] The handle proximal end section 112 is provided with a plasma titanium coating.

[0064] The coating thickness is 0.20 mm and the porosity of the coating is 25%.

[0065] Eight evenly distributed ridges 140 are provided on the middle section of the handle body 110 and the distal section 114 of the handle body from the proximal end to the distal end.

[0066] The handle neck 120 is obliquely arranged above the proximal end 111 of the handle body. The base of the handle neck 120 is smoothly connected to the proximal end 111 of the handle body. A cone head 122 is provided at the free end of the handle neck 120.

[0067] The length of the handle collar 120 is 48 mm.

[0068] The central axis of the handle collar 120 intersects the central axis of the handle body 110 , and the angle formed between the central axis of the handle collar 120 and the central axis of the handle body 110 is 45°;

[0069] A plurality of protrusions 130 , each protrusion 130 being disposed around the periphery of the handle proximal end section 112 and the periphery of the connecting portion 121 between the handle body 110 and the handle neck 120 ;

[0070] Each protrusion 130 has a proximal surface 131, an outer side surface 132 and a distal surface 133 connected in sequence, and the proximal surface 131 and the distal surface 133 are respectively connected to the outer surface of the handle body 110;

[0071] The proximal end surface 131 of each protrusion 130 forms an angle of 85° with the handle body axis 115; the distance between the outer side surface 132 and the outer surface of the handle body 110 is 0.6 mm;

[0072] The plurality of protrusions 130 include a first protrusion 130 and a second protrusion 130 adjacent to each other and arranged from the proximal end to the distal end. The lower end surface of the first protrusion 130 is narrower than the upper end surface of the second protrusion 130. The spacing between adjacent protrusions 130 is 2.0 mm.

[0073] The plurality of protrusions 130 are distributed in a stepped manner from the proximal end to the distal end.

[0074] Example 2

[0075] A hip replacement system includes a hip handle 1. The proximal surface 131 of each protrusion 130 in the hip handle 1 forms an angle of 84° with the handle body axis 115. The remaining structure is the same as the hip handle 1 described in Example 1.

[0076] Example 3

[0077] A hip replacement system includes a hip handle 1. The proximal surface 131 of each protrusion 130 in the hip handle 1 forms an angle of 83° with the handle body axis 115. The remaining structure is the same as the hip handle 1 described in Example 1.

[0078] Comparative Example 1

[0079] A hip replacement system includes a hip handle 1. The proximal surface 131 of each protrusion 130 in the hip handle 1 forms an angle of 82° with the handle body axis 115. The remaining structure is the same as the hip handle 1 described in Example 1.

[0080] Comparative Example 2

[0081] A hip replacement system includes a hip handle 1, wherein the proximal end surface 131 of each protrusion 130 of the hip handle 1 forms a 90° angle with the handle body axis 115, and the remaining structure is the same as the hip handle 1 described in Example 1.

[0082] Comparative Example 3

[0083] A hip replacement system includes a hip handle 1, wherein the proximal end surface 131 of each protrusion 130 of the hip handle 1 forms an angle of 45° with the handle body axis 115, and the remaining structure is the same as the hip handle 1 described in Example 1.

[0084] Comparative Example 4

[0085] A hip replacement system includes a hip handle 1. The proximal surface 131 of each protrusion 130 in the hip handle 1 forms an angle of 60° with the handle body axis 115. The remaining structure is the same as the hip handle 1 described in Example 1.

[0086] The hip handle 1 provided in Examples 1 to 3 and Comparative Examples 1 to 4 was tested and verified (finite element analysis), and the verification results are as follows:

[0087] When the angle between the proximal end surface 131 of the protrusion 130 and the handle body axis 115 is 85°, the distance that the hip handle 1 sinks is 6.210×10 -2 mm;

[0088] When the angle between the proximal end surface 131 of the protrusion 130 and the handle body axis 115 is 84°, the distance the hip handle 1 sinks is 6.241×10 -2 mm;

[0089] When the angle between the proximal end surface 131 of the protrusion 130 and the handle body axis 115 is 83°, the distance the hip handle 1 sinks is 6.263×10 -2 mm;

[0090] When the angle between the proximal end surface 131 of the protrusion 130 and the stem body axis 115 is 82°, the distance the femoral stem sinks is 6.371×10 -2 mm;

[0091] When the angle between the proximal end surface 131 of the protrusion 130 and the handle body axis 115 is 90°, the distance that the hip handle 1 sinks is 6.369×10 -2 mm;

[0092] When the angle between the proximal end surface 131 of the protrusion 130 and the handle body axis 115 is 45°, the distance that the hip handle 1 sinks is 6.630×10 -2 mm;

[0093] When the angle between the proximal end surface 131 of the protrusion 130 and the axis 115 of the handle body is 60°, the distance that the hip handle 1 sinks is 6.503×10 -2 mm.

[0094] It can be seen from the above test results that when the angle between the proximal end surface 131 of the protrusion 130 and the handle body axis 115 is 83°~85°, the sinking distance of the hip handle 1 is smaller than the sinking distance at other angles, that is, when the angle between the proximal end surface 131 of the protrusion 130 and the handle body axis 115 is 83°~85°, the hip handle 1 has the strongest anti-sinking ability.

[0095] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A hip handle, characterized in that include: The handle body comprises a handle body proximal section and a handle body distal section connected to the handle body proximal section, and has a handle body proximal end and a handle body distal end, and is used for implantation into the medullary cavity; a handle neck, which is obliquely arranged above the proximal end of the handle body, with the base of the handle neck smoothly connected to the proximal end of the handle body, and a cone head provided at the free end of the handle neck; and a protrusion, which is arranged on the proximal end section of the handle body and / or the connection between the handle body and the handle neck; the protrusion has a proximal end surface, an outer side surface and a distal end surface connected in sequence, and the proximal end surface and the distal end surface are respectively connected to the outer surface of the handle body; The proximal surface of the protrusion forms an angle of 83° to 85° with the axis of the handle; The distal end surface of the convexity is an arc surface; The protrusions are arranged around the proximal end of the handle body and the outer periphery of the connection between the handle body and the handle neck; there are multiple protrusions, and the multiple protrusions are distributed in a stepped manner from the proximal end to the distal end; The plurality of protrusions include a first protrusion and a second protrusion adjacent to each other and arranged from the proximal end to the distal end. The lower end surface of the first protrusion is radially contracted relative to the upper end surface of the second protrusion.

2. The hip handle according to claim 1, characterized in that: The distance between adjacent protrusions is 1.5-5.0 mm.

3. The hip handle according to claim 1, characterized in that: The distance between the outer side surface and the outer surface of the handle body is 0.4~0.8mm.

4. The hip handle according to any one of claims 1 to 3, characterized in that: The handle body is conical, and the cross-sectional area gradually decreases from the proximal end to the distal end of the handle body. The taper of the handle body is 4° to 6°.

5. The hip handle according to claim 1, characterized in that: The proximal end section of the handle body is provided with a plasma coating; the plasma coating has a thickness of 0.15-0.30 mm and a porosity of 20%-30%.

6. The hip handle according to claim 1, characterized in that: A ridge is provided on the distal end section of the handle body from the proximal end to the distal end.

7. The hip handle according to claim 1, characterized in that: The central axis of the handle neck intersects with the central axis of the handle body, and the angle formed by the central axis of the handle neck and the central axis of the handle body is 40°~50°; the length of the handle neck is 47~49mm, the length of the handle body is 128~132mm, and the length of the proximal section of the handle body is 34~36mm.

8. A hip joint replacement system comprising the hip stem according to any one of claims 1 to 7.

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