Short femoral stem prosthesis for hip joint revision and replacement surgery and manufacturing method of short femoral stem prosthesis

Abstract

The invention relates to the technical field of artificial hip joint prostheses, in particular to a short femoral stem prosthesis for hip joint revision and replacement surgery and a manufacturing method of the short femoral stem prosthesis. Comprising a femoral head cone (1), a femoral neck (2) and a stem body (3) which are sequentially connected. The femoral head cone (1) is used for installing a femoral head prosthesis, and the coronal plane of the femoral neck (2) is gradually increased in the direction from the femoral head cone (1) to the handle body (3); the stem body (3) is configured to be implanted into a femoral medullary cavity and used for replacing an originally implanted ineffective primary replacement femoral stem prosthesis, the stem body (3) comprises a near-end stem body (31) and a far-end stem body (32) which are sequentially connected, the near-end stem body (31) is composed of a porous structure (303) and a stem body base body (315) below the porous structure (303), and the near-end stem body (31) starts from an osteotomy line (307) and ends at a far-end terminating line (308) of the porous structure (303).

Description

Technical Field

[0001] The invention relates to the technical field of artificial hip joint prostheses, and in particular to a short femoral stem prosthesis used for hip joint revision and replacement surgery and a manufacturing method thereof. Background Art

[0002] After the human hip joint has become necrotic, normal human activities can be restored through prosthesis replacement surgery. Specifically, the femoral stem prosthesis is implanted into the femoral medullary cavity, and a ball head is set at the femoral head cone of the femoral stem prosthesis. The ball head is embedded in the acetabulum and rotates with the acetabulum to restore normal human joint activities. If the first implanted hip prosthesis becomes ineffective due to various reasons, a revision surgery is required to replace it with a revised hip prosthesis.

[0003] The revision femoral stem prosthesis currently on sale is usually an extended revision femoral stem prosthesis, and its CT value is usually not less than 200 mm, in order to achieve distal fixation to stabilize and fix the revision femoral stem prosthesis. Since the original failed femoral stem prosthesis needs to be removed during the revision surgery, the proximal trabeculae are lost to a large extent, and the possibility of achieving proximal fixation is reduced. In the prior art, revision femoral stem prostheses are divided into biological type and bone cement type.

[0004] The prior art has the following defects: 1. Further bone loss during distal medullary expansion and reaming. Especially in young patients, one revision is not enough to last until the end of life, and the first revision should not destroy too much bone. 2. Over-reliance on distal fixation leads to proximal stress shielding and accelerated bone resorption; 3. It is necessary to remove the bone and cement base at the distal end of the medullary cavity, which is a cumbersome operation. Sometimes a window is required at the distal end of the femur, and there is a high risk of fracture during the operation.

[0005] Therefore, there is an urgent need for a short femoral stem prosthesis for hip revision replacement surgery and a manufacturing method thereof to solve the above problems. Summary of the invention

[0006] One purpose of the present invention is to provide a short femoral stem prosthesis for hip revision replacement surgery and a method for making the same in order to address the above-mentioned deficiencies. The prosthesis is a biologically fixed revision femoral stem prosthesis with a short stem and a porous structure with a high porosity at the proximal end that is conducive to bone ingrowth. The prerequisite for the biologically fixed femoral stem prosthesis to achieve the expected bone ingrowth and proximal fixation is that the proximal stem body (31) can be press-fitted with the proximal trabeculae after the removal of the primary replacement or revision prosthesis. Under the premise of meeting the strength requirements, the matching degree between the prosthesis and the proximal trabeculae and the distal cortical bone is improved to achieve press-fit and reduce stress shielding.

[0007] To achieve the above-mentioned purpose, the short femoral stem prosthesis for hip joint revision replacement surgery of the present invention adopts the following technical solutions: A short femoral stem prosthesis for hip revision replacement surgery comprises a femoral head cone (1), a femoral neck (2) and a stem body (3) which are connected in sequence; the femoral head cone (1) is used to install the femoral head prosthesis, the coronal plane of the femoral neck (2) is a plane formed by the axes (101) of the femoral head cone (1) and the femoral neck (2) and the axis (310) of the stem body, and the coronal plane of the femoral neck (2) gradually increases in the direction from the femoral head cone (1) to the stem body (3); The handle body (3) is configured to be implanted in the femoral medullary cavity to replace the originally implanted failed primary replacement femoral stem prosthesis, and the handle body (3) comprises a proximal handle body (31) and a distal handle body (32) connected in sequence, wherein the proximal handle body (31) is composed of a porous structure (303) and a handle body base (315) thereunder, and the proximal handle body (31) starts at an osteotomy line (307) and ends at a distal termination line (308) of the porous structure (303); the handle body (3) is composed of the proximal handle body (31) to the distal stem body (33) gradually decreases to adapt to the shape of the proximal femoral medullary; the CT of the femoral stem prosthesis is the maximum distance from the center point of the femoral head (102) installed on the femoral head cone (1) to the most distal arc (309) of the distal stem body (32), the CT of the femoral stem prosthesis is 115 to 145 mm, and the length L of the stem body (3) is 93 to 135 mm, CT and L increase as the specifications of the femoral stem prosthesis increase, and it is a short stem among the existing femoral stem prosthesis design types; The outer wall of the proximal handle body (31) is embedded with a porous structure (303), and the porous structure (303) is configured to contact the trabeculae of the femur. The porous structure (303) covers the proximal end (31), and the length H of the porous structure (303) is 1 / 3-1 / 2 of the length L of the handle body (3), which is conducive to the growth of trabeculae. The femoral head cone (1), the femoral neck (2), the handle (3) and the porous structure (303) are integrally formed.

[0008] The sagittal plane of the distal stem body (32) of the stem body (3) has an included angle α between the front and rear sides of 1° to 3°, gradually increasing from the distal end to the proximal end, while the included angle β between the front and rear sides of the proximal stem body (31) is 3° to 5°, and β of the femoral stem prosthesis of the same specification is greater than α by at least 1°.

[0009] The distal end of the distal handle body (32) is provided with a distal arc (309), and the distal arc (309) is tangentially connected to the front and rear sides through the front and rear arcs (311), so as to avoid stress concentration on the femoral cortical bone that the front and rear sides of the distal handle body (32) may contact.

[0010] The angle θ between the outer and inner sides of the proximal handle body (31) of the coronal plane of the handle body (3) is 5° to 6°, and the outer side extends to the porous structure (303) area of ​​the proximal handle body (31). In order to retain the trabecular bone volume of the proximal femur, the proximal handle body (31) is shoulder-eliminated, and the proximal outer shoulder (304) is cut, and its angle γ is 12° to 15°. The inner side of the proximal handle body (31) is a femoral arc (306) with a radius of 110 mm to 125 mm, and extends to the inner side of the distal handle body (32) and is tangent to the inner side of the distal handle body.

[0011] The farthest end of the distal handle body (32) is the farthest arc (309), which is tangent to the inner side and is tangently connected to the outer side through the distal outer arc (305) to avoid stress concentration in the femoral cortical bone with which the outer distal handle body contacts.

[0012] In the short femoral stem prosthesis used for hip joint revision replacement surgery, the angle ε between the porous structure cutoff line (308) of the proximal stem body (31) and the stem body axis (310) is 45° to 90°.

[0013] In the short femoral stem prosthesis used for hip joint revision replacement surgery, the radius of the inner arc (312) of the cross section AA and the cross section BB of the stem body (3) gradually decreases from the proximal end to the distal end.

[0014] The short femoral stem prosthesis used for hip revision replacement surgery has a cross-section of the distal stem body (32) which is formed by a cross-section line of the anterior and posterior side surfaces (313) tangent to the inner arc (312), a cross-section line of the distal outer anterior and posterior inclined surface (302), and a cross-section line of the distal outer side surface (314), wherein the distal outer anterior and posterior inclined surface (302) extends to the proximal stem body (31).

[0015] The cross section of the proximal handle body (31) is closed by the front and rear side section lines (313) tangent to the circular arc (312), the section lines of the proximal outer front and rear inclined surfaces (301) and the section lines of the proximal outer shoulder surface (304); the proximal handle body (31) is composed of a curved surface formed by the inner circular arc (312) and a handle body base (315) and a porous structure (303) formed by a straight-line surface including the front and rear side surfaces (313), the proximal outer front and rear inclined surfaces (301), the proximal outer shoulder surface (304), part of the distal outer side surface (314) and part of the distal outer front and rear inclined surfaces (302).

[0016] The short femoral stem prosthesis used for hip revision replacement surgery has a proximal stem body (31) that has an increased lateral anterior-posterior inclined surface (301) and a portion of the distal lateral anterior-posterior inclined surface (302) and a porous structure (303) compared to the traditional circular or rectangular designs, thereby increasing the contact area between the proximal femoral trabeculae and the proximal femoral trabeculae, resulting in increased stability after bone ingrowth and increased torsional resistance. The proximal thickness A of the cross section CC of the proximal stem body (31) is greater than the distal thickness B, and the proximal stem body (31) gradually increases from the proximal end to the distal end in order to increase the compressive stress after implantation and promote bone ingrowth.

[0017] The short femoral stem prosthesis used in hip joint revision replacement surgery has a porous structure (303) that is an irregular three-dimensional grid-like structure, and a thickness of the porous structure (303) of 0.7 to 3 mm.

[0018] In the short femoral stem prosthesis for hip revision replacement surgery, the distal stem body (32) is roughened by adjusting the additive manufacturing process parameters to obtain a rough surface with a surface roughness of Ra2-20, thereby increasing the roughness of the stem body and preventing the prosthesis from sinking in the long term.

[0019] The short femoral stem prosthesis used for hip joint revision replacement surgery is made of titanium alloy material.

[0020] The method for manufacturing a short femoral stem prosthesis for hip revision replacement surgery comprises the following steps: S1. Designing the size and shape of the short femoral stem prosthesis for hip revision replacement surgery, and establishing a mechanical model; S2, finding the stress concentration position and the dangerous section of the mechanical model, and optimizing the stress concentration position and the dangerous section; The fatigue strength of the dangerous section and neck of the distal end of the femoral stem was investigated under the action of concentrated load. The stress condition can be simplified to an eccentric compression model. By simplifying the force system, the eccentric compression model can be simplified to a combined compression-bending deformation. The compressive stress , Maximum bending stress , Design requirements should meet , Among them, F is the concentrated force of the test loading. When investigating the fatigue strength of the dangerous section at the distal end of the femoral stem, , when investigating the fatigue strength of the femoral neck, ; is the area of ​​the dangerous section; is the horizontal distance from the danger point to the loading point; is the bending section coefficient of the dangerous section, which is related to the shape and cross-section of the section; The allowable fatigue strength of the femoral stem manufacturing material.

[0021] S3, processing and forming the short femoral stem prosthesis blank for hip joint revision replacement surgery; Titanium alloy powder is used as raw material, in which aluminum Al is 5.5%-6.75%, vanadium V is 3.5%-4.5%, and the rest is titanium Ti (weight percentage). Laser additive manufacturing technology is used to form a femoral stem prosthesis blank, and the head cone and neck are left with processing allowances. Dry ice is used to remove the residual powder in the porous structure of the proximal end of the femoral stem prosthesis blank, and then it is placed in a vacuum sintering equipment for vacuum sintering. The vacuum sintering temperature is 750-850°C and the vacuum degree is 10 -2 Pa, the vacuum sintering time is 30-60 minutes, and the femoral stem prosthesis blank is sintered.

[0022] S4. The short femoral stem prosthesis blank for hip joint revision and replacement surgery is subjected to precision machining, the head cone and other parts are machined, and then the neck is polished, the product is cleaned, and the package is sterilized to produce a finished short femoral stem prosthesis for hip joint revision and replacement surgery.

[0023] The method for manufacturing a short femoral stem prosthesis for hip joint revision replacement surgery is characterized in that: In step S1 , the shape and size of the proximal handle body can be changed according to the preoperative plan.

[0024] In the method for manufacturing the short femoral stem prosthesis for hip revision and replacement surgery, in step S3, the short femoral stem prosthesis for hip revision and replacement surgery is integrally printed using additive manufacturing equipment (3D printer).

[0025] The handle body (3) is generally multi-conical, and compared with the existing cylindrical, conical or double-conical designs, it increases the possibility of producing a press fit with the trabeculae after proximal bone loss after revision.

[0026] The cross-section of the distal handle body (32) is polygonal, which increases the contact area of ​​trabeculae, the possibility of bone ingrowth and the anti-rotation performance of the implant compared to the existing circular and rectangular designs.

[0027] The femoral head cone (1), the femoral neck (2), the handle (3), the reinforcement structure, the support structure and the porous structure (303) are integrally formed. The porous structure is an irregular three-dimensional grid-like structure.

[0028] The short femoral stem prosthesis for hip revision replacement surgery is manufactured using additive manufacturing. The digitalization and flexibility of its product manufacturing can adjust the design of the proximal stem body (31) through preoperative planning to achieve full matching with the postoperative trabeculae and achieve proximal fixation.

[0029] The beneficial effects of the short femoral stem prosthesis of the present invention for hip joint revision replacement surgery are as follows: 1. Preserve bone mass. The short femoral stem prosthesis of the present invention for hip revision replacement surgery only needs to file the proximal end of the femoral medullary cavity, which can maximize the preservation of bone mass. The revision-type extended femoral stem commonly used in the past will further lose bone mass during the process of distal medullary expansion and filing, causing iatrogenic bone destruction; 2. Reduce proximal femoral stress shielding and help proximal bone remodeling. The short femoral stem prosthesis of the present invention is used for hip joint revision and replacement surgery. It is completely press-fitted proximally, so that the proximal femur is subjected to compressive stress. With the help of the 3D printed trabecular structure and HA coating, it induces bone ingrowth and stimulates bone remodeling. It avoids proximal femoral stress shielding and proximal bone absorption caused by excessive reliance on distal fixation in the past revision long stem; 3. Reduce thigh pain. The short femoral stem prosthesis used for hip joint revision replacement surgery concentrates stress on the proximal femur, completely avoiding irritation to the distal femur and reducing the risk of thigh pain in patients. 4. Reduce the risk of distal isthmus fracture. The short femoral stem prosthesis used in hip revision and replacement surgery does not need to grind the distal femur. In patients with osteoporosis, femoral isthmus obstruction and abnormal femoral anterior arch, the distal fixation revision long stem often causes drill bit penetration, isthmus fracture and other problems due to distal femoral medullary expansion. The short femoral stem prosthesis used in hip revision and replacement surgery can completely avoid these problems. 5. The operation is easy and is exactly the same as the initial hip stem replacement, with almost no learning curve. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a coronal view of a femoral stem prosthesis provided by a specific embodiment of a short femoral stem prosthesis for hip joint revision replacement surgery of the present invention.

[0031] Figure 2 It is a sagittal view of a femoral stem prosthesis provided by a specific embodiment of the short femoral stem prosthesis of the present invention for hip joint revision replacement surgery.

[0032] Figure 3 yes Figure 1 AA cross-sectional view of the short femoral stem prosthesis of the present invention for hip revision replacement surgery.

[0033] Figure 4 yes Figure 1BB cross-sectional view of the short femoral stem prosthesis of the present invention for hip revision replacement surgery.

[0034] Figure 5 yes Figure 1 A CC cross-sectional view of a short femoral stem prosthesis of the present invention for use in hip revision replacement surgery.

[0035] Figure 6 It is a flow chart of a method for manufacturing a femoral stem prosthesis provided by a specific embodiment of a short femoral stem prosthesis for hip revision replacement surgery of the present invention.

[0036] In the figure: 1. Femoral head cone; 2. Femoral neck; 3. Stem; 31. proximal handle; 32. distal handle; 101. Femoral head cone axis or femoral neck axis; 102. Femoral head center; 301. Proximal outer anterior-posterior inclined surface; 302. Distal outer anterior-posterior inclined surface; 303. Porous structure; 304. Proximal outer shoulder; 305. Distal outer arc; 306. Femoral calcar arc; 307. Osteotomy line; 308. Cut-off line of porous structure; 309. Farthest arc; 310. Axis of handle body; 311. Anterior and posterior arcs; 312. Medial arc; 313. Anterior and posterior side cross-sectional line; 314. Distal outer side cross-sectional line; 315. Handle body base. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0038] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0041] See attached Figure 1-6 A short femoral stem prosthesis for hip revision replacement surgery comprises a femoral head cone (1), a femoral neck (2) and a stem body (3) connected in sequence; the femoral head cone (1) is used to install the femoral head prosthesis, the coronal plane of the femoral neck (2) is a plane formed by the axes (101) of the femoral head cone (1) and the femoral neck (2) and the axis (310) of the stem body, and the coronal plane of the femoral neck (2) gradually increases in the direction from the femoral head cone (1) to the stem body (3); The handle body (3) is configured to be implanted in the femoral medullary cavity to replace the originally implanted failed primary replacement femoral stem prosthesis, and the handle body (3) comprises a proximal handle body (31) and a distal handle body (32) connected in sequence, wherein the proximal handle body (31) is composed of a porous structure (303) and a handle body base (315) thereunder, and the proximal handle body (31) starts at an osteotomy line (307) and ends at a distal termination line (308) of the porous structure (303); the handle body (3) is composed of the proximal handle body (31) to the distal stem body (33) gradually decreases to adapt to the shape of the proximal femoral medullary; the CT of the femoral stem prosthesis is the maximum distance from the center point of the femoral head (102) installed on the femoral head cone (1) to the most distal arc (309) of the distal stem body (32), the CT of the femoral stem prosthesis is 115 to 145 mm, and the length L of the stem body (3) is 93 to 135 mm, CT and L increase as the specifications of the femoral stem prosthesis increase, and it is a short stem among the existing femoral stem prosthesis design types; The outer wall of the proximal handle (31) is embedded with a porous structure (303), and the porous structure (303) is configured to contact the trabeculae of the femur. The porous structure (303) covers the proximal end (31), and the length of the porous structure (303) is 1 / 3-1 / 2 of the length H of the handle (3), which is conducive to the growth of trabeculae. The femoral head cone (1), the femoral neck (2), the handle (3) and the porous structure (303) are integrally formed. The porous structure is an irregular three-dimensional grid-like structure.

[0042] The sagittal plane of the distal stem body (32) of the stem body (3) has an included angle α between the front and rear sides of 1° to 3°, gradually increasing from the distal end to the proximal end, while the included angle β between the front and rear sides of the proximal stem body (31) is 3° to 5°, and β of the femoral stem prosthesis of the same specification is greater than α by at least 1°.

[0043] The distal end of the distal handle body (32) is provided with a distal arc (309), and the distal arc (309) is tangentially connected to the front and rear sides through the front and rear arcs (311), so as to avoid stress concentration on the femoral cortical bone that the front and rear sides of the distal handle body (32) may contact.

[0044] The angle θ between the outer and inner sides of the proximal handle body (31) of the coronal plane of the handle body (3) is 5° to 6°, and the outer side extends to the porous structure (303) area of ​​the proximal handle body (31). In order to retain the trabecular bone volume of the proximal femur, the proximal handle body (31) is shoulder-eliminated, and the proximal outer shoulder (304) is cut, and its angle γ is 12° to 15°. The inner side of the proximal handle body (31) is a femoral arc (306) with a radius of 110 mm to 125 mm, and extends to the inner side of the distal handle body (32) and is tangent to the inner side of the distal handle body.

[0045] The farthest end of the distal handle body (32) is the farthest arc (309), which is tangent to the inner side and is tangently connected to the outer side through the distal outer arc (305) to avoid stress concentration in the femoral cortical bone with which the outer distal handle body contacts.

[0046] In the short femoral stem prosthesis used for hip joint revision replacement surgery, the angle ε between the porous structure cutoff line (308) of the proximal stem body (31) and the stem body axis (310) is 45° to 90°.

[0047] In the short femoral stem prosthesis used for hip joint revision replacement surgery, the radius of the inner arc (312) of the cross section AA and the cross section BB of the stem body (3) gradually decreases from the proximal end to the distal end.

[0048] The short femoral stem prosthesis used for hip revision replacement surgery has a cross-section of the distal stem body (32) which is formed by a cross-section line of the anterior and posterior side surfaces (313) tangent to the inner arc (312), a cross-section line of the distal outer anterior and posterior inclined surface (302), and a cross-section line of the distal outer side surface (314), wherein the distal outer anterior and posterior inclined surface (302) extends to the proximal stem body (31).

[0049] The cross section of the proximal handle body (31) is closed by the front and rear side section lines (313) tangent to the circular arc (312), the section lines of the proximal outer front and rear inclined surfaces (301) and the section lines of the proximal outer shoulder surface (304); the proximal handle body (31) is composed of a curved surface formed by the inner circular arc (312) and a handle body base (315) and a porous structure (303) formed by a straight-line surface including the front and rear side surfaces (313), the proximal outer front and rear inclined surfaces (301), the proximal outer shoulder surface (304), part of the distal outer side surface (314) and part of the distal outer front and rear inclined surfaces (302).

[0050] The short femoral stem prosthesis used for hip revision replacement surgery has a proximal stem body (31) that has an increased lateral anterior-posterior inclined surface (301) and a portion of the distal lateral anterior-posterior inclined surface (302) and a porous structure (303) compared to the traditional circular or rectangular designs, thereby increasing the contact area between the proximal femoral trabeculae and the proximal femoral trabeculae, resulting in increased stability after bone ingrowth and increased torsional resistance. The proximal thickness A of the cross section CC of the proximal stem body (31) is greater than the distal thickness B, and the proximal stem body (31) gradually increases from the proximal end to the distal end in order to increase the compressive stress after implantation and promote bone ingrowth.

[0051] The short femoral stem prosthesis used in hip joint revision replacement surgery has a porous structure (303) that is an irregular three-dimensional grid-like structure, and a thickness of the porous structure (303) of 0.7 to 3 mm.

[0052] In the short femoral stem prosthesis for hip revision replacement surgery, the distal stem body (32) is roughened by adjusting the additive manufacturing process parameters to obtain a rough surface with a surface roughness of Ra2-20, thereby increasing the roughness of the stem body and preventing the prosthesis from sinking in the long term.

[0053] The short femoral stem prosthesis used for hip joint revision replacement surgery is made of titanium alloy material.

[0054] The method for manufacturing a short femoral stem prosthesis for hip joint revision replacement surgery is characterized in that the method for manufacturing a short femoral stem prosthesis for hip joint revision replacement surgery comprises the following steps: S1. Designing the size and shape of the short femoral stem prosthesis for hip revision replacement surgery, and establishing a mechanical model; S2, finding the stress concentration position and the dangerous section of the mechanical model, and optimizing the stress concentration position and the dangerous section; The fatigue strength of the dangerous section and neck of the distal end of the femoral stem is investigated under the action of concentrated load. The stress condition can be simplified to an eccentric compression model. By simplifying the force system, the eccentric compression model can be simplified to a combined compression-bending deformation. The compressive stress , Maximum bending stress , Design requirements should meet , in, When the fatigue strength of the dangerous section at the distal end of the femoral stem is investigated for the concentrated force of the test load, , when investigating the fatigue strength of the femoral neck, ; is the area of ​​the dangerous section; is the horizontal distance from the danger point to the loading point; is the bending section coefficient of the dangerous section, which is related to the shape and cross-section of the section; The allowable fatigue strength of the femoral stem manufacturing material.

[0055] S3, processing and forming the short femoral stem prosthesis blank for hip joint revision replacement surgery; Titanium alloy powder is used as raw material, in which aluminum Al is 5.5%-6.75%, vanadium V is 3.5%-4.5%, and the rest is titanium Ti (weight percentage). Laser additive manufacturing technology is used to form a femoral stem prosthesis blank, and the head cone and neck are left with processing allowances. Dry ice is used to remove the residual powder in the porous structure of the proximal end of the femoral stem prosthesis blank, and then it is placed in a vacuum sintering equipment for vacuum sintering. The vacuum sintering temperature is 800-850°C and the vacuum degree is 10 -2 Pa, vacuum sintering time is 30-60 minutes (at vacuum degree 10 -2 Pa or less and kept at 800-850°C for 30-60 minutes) to sinter the femoral stem prosthesis blank.

[0056] S4. The short femoral stem prosthesis blank for hip joint revision and replacement surgery is subjected to precision machining, the head cone and other parts are machined, and then the neck is polished, the product is cleaned, and the package is sterilized to produce a finished femoral stem prosthesis.

[0057] The method for manufacturing a short femoral stem prosthesis for hip joint revision replacement surgery is characterized in that: In step S2, the method for optimizing the stress concentration position and the dangerous section includes: changing the shape of the reinforcing structure; increasing the number and / or distribution, and / or position, and / or direction of the reinforcing structure; changing the closure or openness of the reinforcing structure and the cavity inside the handle; and increasing the radius of the connection between the reinforcing structure.

[0058] In the method for manufacturing a short femoral stem prosthesis for hip revision replacement surgery, in step S3, the femoral stem prosthesis is integrally printed using an additive manufacturing device (3D printer). Example

[0059] like Figure 1 As shown, this embodiment provides a short femoral stem prosthesis for hip joint revision replacement surgery, comprising a femoral head cone (1), a femoral neck (2) and a stem body (3) connected in sequence. The femoral head cone (1) is configured to be connected to a ball head, which can be rotatably matched with a ball head groove in the acetabulum to form a hip joint. The coronal surface of the femoral neck (2) gradually increases from the femoral head cone (1) to the stem body (3) to transition to the stem body (3), and the outer wall of the femoral neck (2) is arc-shaped, which can achieve an arc transition connection and avoid stress concentration. The stem body 3 is configured to be implanted in the femoral medullary cavity, and the stem body (3) includes a proximal stem body (31) and a distal stem body (32) connected in sequence, and the coronal surface of the stem body (3) gradually decreases from the proximal stem body (31) to the distal stem body (32) to form a taper.

[0060] It should be noted that the above-mentioned coronal plane refers to the front and back section of the human body. The left and right sections of the human body are called sagittal planes.

[0061] In addition, by providing a porous structure (303) at the position where the proximal handle body (31) of the handle body (3) contacts the trabeculae, on the one hand, the roughness of the surface of the femoral stem prosthesis can be increased, so that the static friction between the prosthesis and the trabeculae is increased, thereby preventing the prosthesis from sinking; on the other hand, the provision of the porous structure (303) is conducive to the growth of human bone tissue, so that the prosthesis and the bone tissue are well matched; in addition, the porous structure (303) is integrally formed with the entire prosthesis, and compared with the existing sandblasting and spraying processes, it can avoid the coating from falling off and increase the service life of the prosthesis.

[0062] The changes in the elastic modulus and plasticity of the prosthesis in this embodiment can effectively reduce the impact of stress shielding, and after the prosthesis is implanted, the human bone tissue can obtain sufficient stress stimulation. In addition, the improvement of the prosthesis plasticity allows the prosthesis to have a greater degree of interference fit with the femur, and the stress on the lateral surface of the femur is significantly increased, effectively reducing the risk of osteoporosis on the lateral surface of the femur.

[0063] The short femoral stem prosthesis used for hip joint revision replacement surgery in this embodiment is made of titanium alloy material, which has the advantages of light weight, high strength, high corrosion resistance, etc., ensuring the quality of the prosthesis after production. Specifically, the femoral stem prosthesis is made of titanium alloy powder (Ti6Al4V powder) through additive manufacturing equipment.

[0064] As attached Figure 6 As shown, this embodiment also provides a method for manufacturing a short femoral stem prosthesis for hip joint revision replacement surgery, which is used to manufacture the femoral stem prosthesis as described above. The method for manufacturing a short femoral stem prosthesis for hip joint revision replacement surgery includes the following steps: S1. Design the size and shape of the short femoral stem prosthesis used for hip revision replacement surgery and establish a simulation model; S2, finding the stress concentration position and dangerous section of the simulation model, and optimizing the stress concentration position and dangerous section; S3, processed femoral stem prosthesis; S4, performing surface treatment on the formed femoral stem prosthesis; S5. Test to verify whether the femoral stem prosthesis meets the mechanical requirements.

[0065] In step S1, the patient's condition can be analyzed medically by means of CT, X-rays, etc., and a femoral stem prosthesis simulation model suitable for the patient can be established according to the specific condition.

[0066] In step S3, the femoral stem prosthesis is integrally printed by using additive manufacturing equipment. The integrally molded femoral stem prosthesis has high strength and does not require welding, turning and other processes.

[0067] In step S4, the surface treatment of the femoral stem prosthesis includes but is not limited to removing surface burrs, improving surface quality, and further processing transition fillets.

[0068] In step S5, the state of the femoral stem prosthesis after implantation in the human body can be simulated, external force can be applied to the femoral stem prosthesis, and it can be monitored whether the prosthesis meets the mechanical requirements.

[0069] The method for making a short femoral stem prosthesis for revision hip replacement surgery provided in this embodiment sets the size and shape of the short femoral stem prosthesis for revision hip replacement surgery according to the individual conditions of the patient, and establishes a simulation model for analysis, so as to optimize the stress concentration position and dangerous cross-section of the prosthesis to ensure that the prosthesis has sufficient strength. After the surface treatment of the prosthesis, it is necessary to test and verify whether the molded prosthesis meets the mechanical requirements. The prosthesis can only be implanted in the human body after being tested and verified to be qualified. Compared with the standardized femoral stem prosthesis in the prior art, this method can customize the prosthesis according to patient differences and personalized needs, so that the prosthesis is more compatible with the patient's bone tissue and speeds up the running-in speed between the patient and the prosthesis.

[0070] The short femoral stem prosthesis of the present invention for hip joint revision replacement surgery and its manufacturing method manufacturing femoral stem prosthesis product test table: Molding product performance:

[0071] Porous structure performance:

[0072] Product pass test:

[0073] GB / T recommended national standards ASTM American Society for Testing and Materials DIN EN ISO are German standards, British standards and international standards. YY / T Pharmaceutical Industry Standard From the analysis of the test table of mechanical properties and fatigue strength test of the femoral stem prosthesis product verified by the above test, the test verifies that the mechanical technical parameters of the femoral stem prosthesis product meet the requirements of relevant national specifications, German standards, British standards, international standards, American Society for Materials and Testing, and pharmaceutical industry standards, and the fatigue strength meets the YY / T0809.4 and YY / T0809.6 pharmaceutical industry standards.

[0074] The present invention belongs to the technical field of artificial hip joint prosthesis, and discloses a short femoral stem prosthesis for hip joint revision replacement surgery and a manufacturing method thereof. The short femoral stem prosthesis for hip joint revision replacement surgery comprises a femoral head cone, a femoral neck and a stem body connected in sequence, and the stem body comprises a proximal end, a middle section structure and a distal end connected in sequence; the outer wall of the proximal end is embedded with a porous structure, and the porous structure contacts the trabeculae of the femur. The entire prosthesis is formed in one piece.

[0075] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A short femoral stem prosthesis for hip joint revision replacement surgery, characterized in that: It comprises a femoral head cone (1), a femoral neck (2) and a handle body (3) which are connected in sequence; the femoral head cone (1) is used to install a femoral head prosthesis, the coronal plane of the femoral neck (2) is a plane formed by the axes (101) of the femoral head cone (1) and the femoral neck (2) and the axis (310) of the handle body, and the coronal plane of the femoral neck (2) gradually increases in the direction from the femoral head cone (1) to the handle body (3); The handle body (3) is configured to be implanted in the femoral medullary cavity to replace the failed primary replacement femoral stem prosthesis that was originally implanted. The handle body (3) comprises a proximal handle body (31) and a distal handle body (32) that are connected in sequence, wherein the proximal handle body (31) is composed of a porous structure (303) and a handle body base (315) thereunder, and the proximal handle body (31) starts at an osteotomy line (307) and ends at a distal termination line (308) of the porous structure (303); the handle body (3) is composed of the proximal handle body ( 31) to the distal stem body (32) gradually decreases to adapt to the shape of the proximal femoral medullary; the CT of the femoral stem prosthesis is the maximum distance from the center point of the femoral head (102) installed on the femoral head cone (1) to the most distal arc (309) of the distal stem body (32), the CT of the femoral stem prosthesis is 115 to 145 mm, and the length L of the stem body (3) is 93 to 135 mm, CT and L increase as the specifications of the femoral stem prosthesis increase, and it is a short stem among the existing femoral stem prosthesis design types; The outer wall of the proximal handle (31) is embedded with a porous structure (303), and the porous structure (303) is configured to contact the trabeculae of the femur. The porous structure (303) covers the proximal end (31), and the length H of the porous structure (303) is 1 / 3-1 / 2 of the length L of the handle (3), which is conducive to the growth of trabeculae. The femoral head cone (1), the femoral neck (2), the handle body (3) and the porous structure (303) are integrally formed.

2. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The sagittal plane of the stem body (3) is a plane perpendicular to the coronal plane, and the angle α between the front and rear sides of the distal stem body (32) of the sagittal plane of the stem body (3) is 1° to 3°, gradually increasing from the distal end to the proximal end, while the angle β between the front and rear sides of the proximal stem body (31) is 3° to 5°, and β of the femoral stem prosthesis of the same specification is greater than α by at least 1°.

3. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1 or 2, characterized in that: The distal end of the distal handle body (32) is provided with a distal arc (309), and the distal arc (309) is tangentially connected to the front and rear sides through the front and rear arcs (311), so as to avoid stress concentration on the femoral cortical bone that the front and rear sides of the distal handle body (32) may contact.

4. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The angle θ between the outer and inner sides of the distal handle body (32) is 5° to 6°, and the outer side extends to the porous structure (303) area of ​​the proximal handle body (31). In order to retain the trabecular bone volume of the proximal femur, the proximal handle body (31) is shoulder-reduced, and the proximal outer shoulder (304) is cut, and its angle γ is 12° to 15°. The inner side of the proximal handle body (31) is a femoral arc (306) with a radius of 95 mm to 125 mm, which extends to the inner side of the distal handle body (32) and is tangent to the inner side of the distal handle body.

5. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 4, characterized in that: The farthest end of the distal handle body (32) is the farthest arc (309), which is tangent to the inner side and is tangently connected to the outer side through the distal outer arc (305) to avoid stress concentration on the femoral cortical bone with which the outer distal handle body contacts.

6. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The angle ε between the porous structure cutoff line (308) of the proximal handle body (31) and the handle body axis (310) is 45° to 90°.

7. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The radius of the inner circular arc (312) of the cross sections AA and BB of the handle body (3) gradually decreases from the proximal end to the distal end.

8. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The cross section of the distal handle body (32) is formed by the cross-sectional lines of the front and rear side surfaces (313) tangent to the inner circular arc (312), the cross-sectional lines of the distal outer front and rear inclined surfaces (302), and the cross-sectional lines of the distal outer side surfaces (314), wherein the distal outer front and rear inclined surfaces (302) extend to the proximal handle body (31).

9. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The cross section of the proximal handle body (31) is closed by the front and rear side section lines (313) tangent to the circular arc (312), the section lines of the proximal outer front and rear inclined surfaces (301) and the section lines of the proximal outer shoulder surface (304); the proximal handle body (31) is composed of a curved surface formed by the inner circular arc (312) and a handle body base (315) and a porous structure (303) formed by a straight-line surface including the front and rear side surfaces (313), the proximal outer front and rear inclined surfaces (301), the proximal outer shoulder surface (304), part of the distal outer side surface (314) and part of the distal outer front and rear inclined surfaces (302).

10. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 8 or 9, characterized in that: Compared with the traditional circular or rectangular designs, the proximal handle body (31) has an increased outer anterior-posterior inclined surface (301) and a portion of the distal outer anterior-posterior inclined surface (302) and a porous structure (303) in contact with the proximal femoral trabeculae, resulting in increased stability after bone ingrowth and increased torsional resistance. The proximal thickness A of the cross section CC of the proximal handle body (31) is greater than the distal thickness B, and the proximal handle body (31) gradually increases from the distal end to the proximal end in order to increase the compressive stress after implantation and promote bone ingrowth.

11. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The porous structure (303) is an irregular three-dimensional grid-like structure, and the thickness δ of the porous structure (303) is 0.7 to 3 mm.

12. The short femoral stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The distal handle body (32) is provided with a rough surface having a surface roughness of Ra2-20 by adjusting additive manufacturing process parameters, thereby increasing the roughness of the handle body and preventing the prosthesis from sinking in the long term.

13. The short femoral stem prosthesis for hip joint revision replacement surgery according to any one of claims 1 to 12, characterized in that: The short femoral stem prosthesis used for hip joint revision replacement surgery is made of titanium alloy material.

14. The method for manufacturing a short-stem prosthesis for hip joint revision replacement surgery according to claim 1, characterized in that: The method for manufacturing a short femoral stem prosthesis for hip joint revision replacement surgery comprises the following steps: S1. Designing the size and shape of the short femoral stem prosthesis for hip revision replacement surgery, and establishing a mechanical model; S2, finding the stress concentration position and the dangerous section of the mechanical model, and optimizing the stress concentration position and the dangerous section; The fatigue strength of the dangerous section and neck of the distal end of the femoral stem was investigated under the action of concentrated load. The stress condition can be simplified to an eccentric compression model. By simplifying the force system, the eccentric compression model can be simplified to a combined compression-bending deformation. The compressive stress , Maximum bending stress , Design requirements should meet , in When the fatigue strength of the dangerous section at the distal end of the femoral stem is investigated for the concentrated force of the test load, , when investigating the fatigue strength of the femoral neck, ; is the area of ​​the dangerous section; is the horizontal distance from the danger point to the loading point; is the bending section coefficient of the dangerous section, which is related to the shape and cross-section of the section; The allowable fatigue strength of the material used to make the femoral stem; S3, processing and forming the short femoral stem prosthesis blank for hip joint revision replacement surgery; Titanium alloy powder is used as raw material, in which aluminum Al is 5.5%-6.75%, vanadium V is 3.5%-4.5%, and the rest is titanium Ti (weight percentage). Laser additive manufacturing technology is used to form a femoral stem prosthesis blank, and the head cone and neck are left with processing allowances. Dry ice is used to remove the residual powder in the porous structure of the proximal end of the femoral stem prosthesis blank, and then it is placed in a vacuum sintering equipment for vacuum sintering. The vacuum sintering temperature is 750-850°C and the vacuum degree is 10 -2 Pa below, the vacuum sintering time is 30-60 minutes, and the femoral stem prosthesis blank is sintered; S4. The short femoral stem prosthesis blank for hip joint revision and replacement surgery is subjected to precision machining, the head cone and other parts are machined, and then the neck is polished, the product is cleaned, and the package is sterilized to produce a finished short femoral stem prosthesis for hip joint revision and replacement surgery.

15. The method for manufacturing a short femoral stem prosthesis for hip joint revision replacement surgery according to claim 14, characterized in that: In step S3, the short femoral stem prosthesis for hip revision replacement surgery is printed in one piece using additive manufacturing equipment (3D printer).

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