A femoral stem prosthesis

Abstract

The application provides a femoral stem prosthesis, which comprises a femoral stem, an expansion component and a sleeve. The femoral stem is composed of an upper stem body and a replaceable lower stem body, and is internally provided with a thread. The expansion component is located in the upper stem body and comprises a screw, a rotating disc and a multi-layer pushing structure. The screw is connected with the upper and lower stem bodies through the thread; the rotating disc is in threaded engagement with the screw and can drive a first pushing part along a first guide rail when rotating. The rail component contains a ratchet, which is in engagement with a pawl of a second pushing part, and the second pushing part is laterally provided with an opening. The sleeve is linked with the expansion component through a fifth pushing part, a fourth pushing part and a third pushing part. When implanted, the second pushing part pushes the sleeve outward to adhere to the wall of the medullary cavity, and the reaction force makes the internal pushing structure act successively, so that the first pushing part is finally separated from the second pushing part. Then, bone cement is injected through the micropore of the sleeve, so as to enhance the stability of the prosthesis. The design realizes intraoperative adaptation and stable filling.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, and in particular, to a femoral stem prosthesis. BACKGROUND

[0002] Total hip arthroplasty is an effective means to treat end-stage hip diseases (such as osteonecrosis of the femoral head, osteoarthritis, femoral neck fracture, etc.), and its core goal is to relieve pain, restore joint function, and achieve long-term stability. The initial stability and long-term biomechanical performance of the femoral stem prosthesis after implantation are important factors that determine the success or failure of the surgery.

[0003] At present, the femoral stem prostheses commonly used in clinical practice mainly include cemented and non-cemented (biological) types. Non-cemented prostheses rely on the tight press-fit between the prosthesis and the host bone to achieve initial stability, and obtain long-term stability through bone growth. To achieve this goal, the design of the prosthesis must be highly matched with the anatomical morphology of the proximal femoral medullary cavity.

[0004] However, the human femoral medullary cavity, especially the proximal medullary cavity, has a large individual variability in anatomy. Standard conical or cylindrical femoral stem prostheses, while meeting the needs of most routine cases, face serious challenges in matching and stability when faced with the following situations:

[0005] Developmental deformity: In patients with congenital hip dysplasia (DDH), the proximal femoral medullary cavity often has irregular shapes such as narrowness, abnormal anteversion angle, or shallowness.

[0006] Revision surgery: After the failure of the initial joint replacement, due to the removal of the original prosthesis, bone resorption, bone defects, and other reasons, the medullary cavity structure has been severely damaged and is extremely irregular in shape.

[0007] Pathological bone: In patients with rheumatoid arthritis or advanced osteoporosis, the bone quality is poor, the medullary cavity is wide, and the cortical bone is not thin, which cannot provide sufficient support for standard prostheses.

[0008] Specific population: Some Asian women or short-statured patients have small and special-shaped medullary cavities, making it difficult for standard prostheses to completely fit.

[0009] The existing technology mainly adopts two approaches to solve the above problems:

[0010] Increase the number of prostheses: By providing more sizes and shapes of prostheses to cover a wider range of anatomical variations. However, this method has limitations such as complex inventory management and high cost, and still cannot cover all extreme or irregular medullary cavity shapes.

[0011] Using modular prostheses: combining through modular proximal and distal components to fit different medullary cavities. However, such prostheses are usually structurally complex, there is a risk of micromotion and corrosion at the connection site, and their adaptability is still limited to the preset modular component morphology.

[0012] In the anatomy of the proximal femur, the lateral region of the medullary cavity (femoral condyle region) is a key site for load bearing and stress transmission. The fit of standard femoral stem prostheses at this site is often insufficient, leading to two major problems:

[0013] First, the "lateral gap" appears: there is a gap between the lateral cortex of the femur and the lateral side of the prosthesis, so that stress cannot be effectively transmitted to the bone in this area through the prosthesis, violating the physiological principle of stress transmission, which may cause stress shielding, and in turn lead to bone resorption and bone loss in this area, long-term affecting the stability of the prosthesis.

[0014] Second, the stability of the prosthesis decreases: the prosthesis lacking lateral support is prone to varus displacement or micromotion under weight-bearing, affecting the initial stability and hindering the process of bone growth, increasing the risk of aseptic loosening.

[0015] Therefore, there is an urgent need in the art for a new design of femoral stem prosthesis that can actively and effectively adapt to irregular medullary cavities, especially one that can closely fit and support the key lateral cortex of the femur, to overcome the above-mentioned deficiencies of the prior art. SUMMARY

[0016] The main purpose of the present application is to provide a femoral stem prosthesis to solve the problem that the proximal end of the femoral stem prosthesis in the prior art cannot fit irregular medullary cavities.

[0017] In order to achieve the above object, the present application provides a femoral stem prosthesis, which specifically comprises: a femoral stem, which comprises an upper stem body and a lower stem body, the inside of the upper stem body is partially hollow, the top of the upper stem body is provided with a circular first opening hole penetrating into the inside of the upper stem body, and the side of the upper stem body is also uniformly provided with six rectangular second opening holes; an expansion component, which is arranged in the hollow inside of the upper stem body, the expansion component comprises: a screw, which is inserted into the upper stem body through the first opening hole, and the lower part of the screw is provided with a second thread; a rotating disc, which is a disc, the middle part of the rotating disc is provided with a penetrating third thread, the third thread is engaged with the second thread of the screw, the screw drives the rotating disc to rotate when the screw rotates, and the rotating disc is also uniformly provided with six first guide rails, the guide rails are provided with first pushing parts inside, the lower part of the rotating disc is provided with a track component, the middle part of the track component is a rectangular hole penetrating the upper part thereof, and the inner walls of the two sides of the track component are symmetrically provided with ratchets; the track component is correspondingly provided with a second pushing part inside, the two sides of the second pushing part are symmetrically provided with first recesses, the first recesses are provided with ratchet pawl parts engaged with the ratchets, the upper part of the second pushing part is provided with a circular third opening hole, the first pushing parts can be inserted into the second pushing parts through the third opening hole, the side of the second pushing part is also provided with a rectangular fourth opening hole, and the inside of the second pushing part is also provided with a first hole; a sleeve, which is sleeved on the neck of the femoral stem, the sleeve comprises a combined body composed of a third pushing part, a first connecting part, a fourth pushing part and a fifth pushing part, and a sleeve unit connected with the combined body, the combined body is placed in the first hole of the second pushing part, the third pushing part is a cylindrical body with a height and a diameter matched with the third opening hole, the fourth pushing part is an elastic component with an arc shape, the fifth pushing part is arranged between the fourth pushing part and the sleeve, the fifth pushing part extends out of the second opening hole and is connected with the sleeve, and the sleeve is pushed to expand outward to realize adhesion with the medullary cavity.

[0018] Further, the diameter of the first opening hole is consistent with the diameter of the screw, the screw can extend into the upper stem body of the femoral stem through the first opening hole, the middle part of the solid part in the inside of the upper stem body is provided with a first thread, and the first thread is engaged with the second thread on the screw.

[0019] Further, the lower stem body is a solid stem body, the lower stem body is also provided with a first thread, the screw can realize the connection of the upper stem body and the lower stem body through the mutual engagement of the second thread and the first thread, and the lower stem body is replaceable, has different specifications and sizes, is provided with the first thread, and different specifications of the lower stem body can adapt to different situations.

[0020] Further, the first guide rail is circular arc-shaped and penetrates the rotating disc, and the rotating disc can drive the first pushing part placed in the first guide rail to move when the rotating disc rotates; the first pushing part comprises an upper pushing block and a lower pushing block, both of which are cylindrical, the diameter of the upper pushing block is larger than that of the lower pushing block, the diameter of the lower pushing block is consistent with the width of the first guide rail, the height of the lower pushing block is larger than the height of the first guide rail, so that the first pushing part can be placed in the first guide rail and will not fall into the first guide rail completely, and the diameter of the lower pushing block is consistent with the diameter of the third opening, so that the lower pushing block can extend into the second pushing part through the third opening.

[0021] Further, the first recesses on both sides of the second pushing part are aligned with the first fixing blocks, the middle of the first fixing blocks is provided with a rotating rod, the pawl part is hingedly connected with the first fixing blocks through the rotating rod, and the second pushing part can be prevented from being retreated through the engagement of the pawl part and the ratchet on the track part.

[0022] Further, the middle of the first hole is a semicircular hole with a height larger than that of the fourth pushing part, the left side of the first hole is a rectangular hole, and the right side of the first hole is a rectangular hole penetrating to the fourth opening; the first hole is connected with the third opening and the fourth opening, so that the first pushing part can extend into the first hole through the third opening.

[0023] Further, the sleeve is composed of six sleeve units, the sleeve has a certain ductility, so that the sleeve can be pushed to be attached to the medullary cavity, and the sleeve is provided with a micro-hole at the top, bone cement can be injected into the sleeve through the micro-hole; meanwhile, the fourth pushing part is provided with a first connecting part on the side away from the sleeve, the third pushing part is arranged at the top of the fourth pushing part and is connected and fixed with the fourth pushing part, and when the fourth pushing part is extruded and pushed, the third pushing part can be lifted.

[0024] Further, the combination of the third pushing part, the first connecting part, the fourth pushing part and the fifth pushing part is placed in the first hole, and since the fourth pushing part is an elastic part, the fourth pushing part can be extruded in the first hole to lift the third pushing part.

[0025] The application discloses a femoral stem prosthesis, which comprises a femoral stem, an expansion component and a sleeve.The femoral stem comprises an upper stem body and a lower stem body, the upper stem body is provided with a circular first opening at the upper part and six rectangular second openings at the side surface, the upper stem body and the lower stem body are provided with a first thread inside, and the lower stem body is replaceable and has different specifications.The expansion component is arranged in the hollow inside of the upper stem body, and the expansion component comprises a screw, a rotating disc, a first pushing part, a track component and a second pushing part, the screw is provided with a second thread at the lower part, the second thread is engaged with the first thread inside the upper stem body and the lower stem body, the screw is connected and combined with the upper stem body and the lower stem body to form the femoral stem prosthesis through the engagement of the threads, the rotating disc is provided with a third thread at the middle part, the third thread is engaged with the second thread of the screw, the screw can drive the rotating disc to rotate when being screwed in, the rotating disc is uniformly provided with six arc-shaped first guide rails on the upper part, the first pushing part is inserted into the first guide rail, the track component is arranged at the lower part of the rotating disc and corresponds to the first guide rail, the track component is provided with a rectangular hole at the middle part and is provided with ratchet teeth on the inner walls of the two sides, the second pushing part is arranged inside the track component, the second pushing part is provided with a first recess on the two sides, the first recess is provided with a pawl part, the pawl part is engaged with the ratchet teeth inside the track component, the second pushing part is provided with a circular second opening at the upper part and a rectangular fourth opening at the side surface, the first pushing part can be inserted into the second pushing part through the second opening, the second pushing part is provided with a first hole, the middle part of the first hole is a semicircular hole with a height greater than that of the fourth pushing part, the left side is a rectangular hole, and the right side is a rectangular hole penetrating the fourth opening.The sleeve is arranged on the neck of the femoral stem, the sleeve is connected with a fifth pushing part extending from the second opening, the fifth pushing part is connected with a fourth pushing part away from the sleeve, the fourth pushing part is an arc-shaped elastic component, a third pushing part is arranged on the top of the fourth pushing part, the third pushing part is a cylindrical body with a height and a diameter matched with the third opening, the third pushing part can be lifted into the third opening by the fourth pushing part, the fourth pushing part is provided with a first connecting part, one end of the first connecting part away from the fourth pushing part is connected with the second pushing part to play a fixing role, and the combination of the first connecting part, the third pushing part, the fourth pushing part and the fifth pushing part is placed in the first hole, the sleeve can be moved to the marrow cavity wall when the second pushing part is pushed out, when the sleeve collides with the marrow cavity wall, the reaction force makes the fifth pushing part move inward to press the fourth pushing part, the fourth pushing part is lifted to lift the third pushing part, the third pushing part is lifted to move the first pushing part out of the third opening, the first pushing part is separated from the second pushing part, the sleeve is provided with a micro hole, and the sleeve is filled with bone cement through the micro hole when the movement of the sleeve is completed, so that the femoral stem prosthesis is more stable.

[0026] Therefore, the technical scheme of the present application can solve the problem that the prior art cannot actively and effectively adapt to irregular marrow cavities, especially cannot closely fit and support the key lateral cortex of the femur. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which form a part of the present description, illustrate the present application and together with the written description serve to explain the application. In the drawings:

[0028] Figure 1 A schematic diagram of the femoral stem prosthesis is shown;

[0029] Figure 2 A schematic diagram of the combination of the upper stem body and the lower stem body is shown;

[0030] Figure 3 A sectional view of the femoral stem prosthesis is shown;

[0031] Figure 4 A schematic diagram of the expansion component is shown;

[0032] Figure 5 A sectional view of the combination of the track component, the second pushing part and the sleeve is shown;

[0033] Figure 6 A schematic diagram of the second pushing part is shown;

[0034] Figure 7 A sectional view of the second pushing part is shown;

[0035] Figure 8 A schematic diagram of the sleeve is shown;

[0036] In the above drawings, the following reference signs are used: 1, femoral stem; 10, upper stem body; 100, first opening; 101, second opening; 11, lower stem body; 12, first thread; 2, expansion component; 20, screw; 200, second thread; 21, rotating disc; 210, third thread; 211, first guide rail; 22, first pushing part; 220, upper pushing block; 221, lower pushing block; 23, track component; 230, ratchet; 24, second pushing part; 240, first recess; 241, pawl part; 242, first fixing block; 243, rotating rod; 244, third opening; 245, fourth opening; 246, first hole; 3, sleeve; 30, third pushing part; 31, first connecting part; 32, fourth pushing part; 33, fifth pushing part; 34, micropore. DETAILED DESCRIPTION

[0037] Clearly, the described embodiments are only some, but not all, embodiments of the present application. Various modifications and changes can be made thereto by those skilled in the art which freelyproceed from the concepts disclosed herein without departing from the spirit of the application. It is therefore intended that the disclosed application be considered as in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0038] It is also noted that the embodiments can be described as a process, which is depicted as a flowchart, a flow diagram, a flow chart, a flow diagram, and / or a sequence diagram. Although a variety of elements are presented with respect to the method, the order in which the elements are presented on the flow diagram is not meant to be limiting and only suggests one ordering of the elements. The method can be practiced with more or fewer steps or elements described, and with additional or different elements than those described or shown. The method can be implemented with computer-executable instructions. The computer-executable instructions can be in the form of a program which can be executable by a computer.

[0039] Unless specifically stated otherwise, the relative arrangements of the components and steps exemplified in the embodiments and the numerical expressions and values set forth herein are not limiting and are intended to be illustrative only. It is to be understood that the various techniques and methods described herein are exemplary in nature, and that these techniques and methods can be utilized in various combinations, sequences or orders of deployment, and / or with other techniques and methods, without departing from the scope of the present application. Also, the description as set forth herein is not intended to be complete description of all features of the application and thus, various embodiments can not be described in detail. It is also to be understood that the terminology used herein is for the purpose of describing the embodiments only and the technology can be practiced with other terms. Furthermore, as used herein, the term "and / or" means "and" or "or", for example, "A and / or B" means "A and B" or "A or B".

[0040] As Figures 1-8As shown: a femoral stem prosthesis, comprising a femoral stem 1, the femoral stem 1 comprising an upper stem body 10 and a lower stem body 11, the upper stem body 10 being partially hollow inside, the upper stem body 10 being provided with a circular first opening 100 at the top, and six rectangular second openings 101 being uniformly arranged on the side surface, a first thread 12 being arranged inside the solid part of the upper stem body 10 and the lower stem body 11; an expansion component 2 being arranged in the hollow interior of the upper stem body 10, the expansion component 2 comprising a screw 20 extending into the interior of the upper stem body 10 from the first opening 100, the screw 20 being provided with a second thread 200 at the lower part, the second thread 200 being engaged with the first thread 12, the expansion component 2 further comprising a rotating disc 21, the rotating disc 21 being provided with a third thread 210 penetrating through the middle part, the screw 20 penetrating through the rotating disc 21, the second thread 200 being engaged with the third thread 210, the rotating disc 21 being uniformly provided with six first guide rails 211, the first guide rails 211 being arc-shaped and penetrating through the rotating disc 21 from top to bottom, a first pushing part 22 being arranged in the first guide rail 211, the first pushing part 22 comprising an upper pushing block 220 and a lower pushing block 221, a track component 23 being correspondingly arranged at the lower part of the first guide rail 211, the track component 23 being provided with a rectangular cutout penetrating through the middle part of the upper part, and being provided with symmetrical ratchet teeth 230 on the inner walls of the two sides, a second pushing part 24 being correspondingly arranged inside the track component 23, the second pushing part 24 being provided with symmetrical rectangular first recesses 240 on the two sides, ratchet pawl parts 241 being arranged in the first recesses 240, the ratchet pawl parts 241 being hingedly connected with first fixed blocks 242 through rotating rods 243, the ratchet pawl parts 241 being engaged with the ratchet teeth 230 on the track component 23, the second pushing part 24 being provided with a circular third opening 244 at the upper part, the diameter of the third opening 244 being consistent with the diameter of the lower pushing block 221 of the first pushing part 22, the second pushing part 24 being provided with a rectangular fourth opening 245 on the side surface, the second pushing part 24 being provided with a first cutout 246 inside, the first cutout 246 being a semicircular cutout in the middle part, a rectangular cutout on the left side, and a rectangular cutout penetrating through the fourth opening 245 on the right side, the first cutout 246 being connected with the third opening 244 and the fourth opening 245.A sleeve 3 is fitted around the neck of the femoral stem 1. The sleeve 3 consists of six sleeve units and has a certain degree of extensibility. A micro-hole 34 is provided at the top of the sleeve 3. A fifth pushing part 33 extending from the second opening 101 is connected to the sleeve 3. The fifth pushing part 33 is connected to a fourth pushing part 32, which is an arc-shaped elastic component. A third pushing part 30 is connected to the top of the fourth pushing part 32. The third pushing part 30 is a cylinder with a height and diameter matching the third opening 244. The third pushing part 30 can be lifted into the third opening 244. A first connecting part 31 is connected to the side of the fourth pushing part 32 away from the sleeve 3. The combination of the third pushing part 30, the first connecting part 31, the fourth pushing part 32, and the fifth pushing part 33 is placed in the first hole 246.

[0041] like Figure 1 As shown, a femoral stem prosthesis includes a femoral stem 1, which includes an upper stem body 10 and a lower stem body 11. A sleeve 3 is fitted around the neck of the femoral stem 1. The sleeve 3 is composed of six sleeve units and has a certain degree of extensibility. A screw 20 is inserted into the top of the femoral stem 1 and the screw 20 connects and fixes the upper stem body 10 and the lower stem body 11.

[0042] like Figure 2 As shown, the femoral stem 1 includes an upper stem body 10 and a lower stem body 11. The top of the upper stem body 10 is provided with a circular first opening 100, and the side of the upper stem body 10 is provided with six rectangular second openings 101 evenly distributed.

[0043] like Figure 3 As shown, the femoral stem prosthesis includes a femoral stem 1, which comprises an upper stem body 10 and a lower stem body 11. The upper stem body 10 is partially hollow. A first thread 12 is provided inside both the upper stem body 10 and the lower stem body 11. An extension component 2 is provided inside the upper stem body 10. The extension component 2 includes a screw 20, with a second thread 200 at its lower part. The extension component 2 also includes a turntable 21, which includes a third thread 210 and a first guide rail 211. A first pushing part 22 is inserted into the first guide rail 211, and a track component 23 is correspondingly provided at the lower part of the first guide rail 211. The second thread 200 on the screw 20 meshes with the first thread 12 inside the femoral stem 1, thus connecting and fixing the upper stem body 10 and the lower stem body 11. Simultaneously, the second thread 200 on the screw 20 meshes with the third thread inside the turntable 21. Therefore, the screw 20... When rotating, it can drive the turntable 21 to rotate, and at the same time drive the first push part 22 in the first guide rail 211 to move.

[0044] like Figure 4As shown, the expansion component 2 includes a screw 20, the lower part of which is provided with a second thread 200, and a rotating disc 21, the middle part of which is provided with a third thread 210 penetrating through, the screw 20 penetrating through the rotating disc 21 and engaging with the third thread 210, and the rotating disc 21 being able to rotate when the screw 20 rotates, and the rotating disc 21 is further uniformly provided with six first guide rails 211, which are arc-shaped and penetrate through the rotating disc 21, and the first guide rails 211 are correspondingly provided with first pushing parts 22 inside, the upper part of the first pushing part 22 having a larger diameter than the width of the first guide rail 211, and the lower part of the first guide rail 211 is correspondingly provided with a track component 23, the middle part of which is a rectangular hole penetrating through the upper part, and the inner walls on both sides are symmetrically provided with ratchets 230, and the track component 23 is correspondingly provided with a second pushing part 24 inside, and a fifth pushing part 33 extends out of a fourth opening 245 of the second pushing part 24 to be connected with the sleeve 3.

[0045] As shown in Figure 5 the second pushing part 24 is provided in the track component 23, the inner walls on both sides of the track component 23 are symmetrically provided with ratchets 230, the two sides of the pushing part 24 are symmetrically provided with first recesses 240, the two sides of the second pushing part 24 are provided with first fixed blocks 242, the first fixed blocks 242 are provided with rotating rods 243 inside to realize hinged connection with pawl parts 241, the pawl parts 241 and the ratchets 230 are mutually engaged to realize the retreat prevention function of the second pushing part 24; the second pushing part 24 is further provided with a first hole 246 inside, and the fifth pushing part 33 placed in the first hole 246 extends out of the fourth opening 245 of the second pushing part 24 to be connected with the sleeve 3, and the sleeve 3 is provided with a micro-hole 34.

[0046] As shown in Figure 6 the two sides of the second pushing part 24 are symmetrically provided with first recesses 240, the first recesses 240 are correspondingly provided with pawl parts 241 inside, and the pawl parts 241 are hingedly connected with the first fixed blocks 242 through rotating rods 243; the first pushing part 22 includes an upper pushing block 220 and a lower pushing block 221, the diameter of the upper pushing block 220 is larger than that of the lower pushing block 221, the diameter of the lower pushing block 221 is consistent with that of a third pushing part 30, and the first pushing part 22 is placed on the third pushing part 30, and the third pushing part 30 is placed in the first hole 246 inside the second pushing part 24.

[0047] As shown in Figure 7As shown, the second pushing part 24 is provided with a third opening 244, a fourth opening 245 and a first hole 246. The third opening 244 is a circular opening that extends through to the first hole 246. The first hole 246 has a semi-circular hole in the middle with a height greater than that of the fourth pushing part 32, a rectangular hole on the left side and a rectangular hole on the right side that extends through to the fourth opening 245.

[0048] like Figure 8 As shown, the sleeve 3 is composed of six sleeve units. The sleeve 3 has a certain degree of extensibility. A micro-hole 34 is provided at the top of the sleeve 3. The sleeve 3 is connected to the fifth pushing part 33. The other end of the fifth pushing part 33 is connected to the fourth pushing part 32. The fourth pushing part 32 is an arc-shaped elastic component. A third pushing part 30 is connected to the top of the fourth pushing part 32. A first connecting part 31 is connected to the side of the fourth pushing part 32 away from the sleeve 3. The combination of the third pushing part 30, the first connecting part 31, the fourth pushing part 32 and the fifth pushing part 33 is placed in the first hole 246.

[0049] When the application is used, the specific technical effects brought by the embodiment are as follows: before the operation, a suitable specification of the lower handle body is selected, and during the operation, the lower handle body is implanted first, and then the upper handle body is implanted into the medullary cavity and aligned with the lower handle body; after the position is determined according to the preoperative planning, the screw is slowly screwed into the femoral stem through the first opening of the upper handle body; when the screw is screwed into the rotating disc and contacts the third screw thread in the rotating disc, the rotating disc will rotate slowly at this time, and the first pushing part inserted into the first guide rail will move slowly along the track of the first guide rail; since the first pushing part is inserted into the first digging hole through the third opening on the second pushing part and contacts the third pushing part at this time, the second pushing part is slowly moved outward along the track part along with the movement of the first pushing part, and the pawl parts on both sides of the second pushing part also move at this time; the fifth pushing part in the first digging hole inside the second pushing part moves outward along with the movement of the second pushing part, and then the fifth pushing part pushes the sleeve to move towards the medullary cavity wall; when the sleeve contacts the medullary cavity wall, the medullary cavity wall exerts a reaction force on the sleeve, so that the fifth pushing part moves reversely and extrudes the fourth pushing part; since the fourth pushing part is an elastic part, the fourth pushing part is extruded and bent and is lifted upward, thereby lifting the third pushing part, and the third pushing part lifts the first pushing part until the first pushing part is slowly pushed out of the third opening; at this time, after the first pushing part leaves the second pushing part, the second pushing part loses the driving force and stops moving, and at this time, the pawl parts on both sides of the second pushing part stop moving and mesh with the ratchet teeth of the track part, thereby achieving the overall stop effect of the second pushing part. Since the six second pushing parts work independently, the stop of one second pushing part does not affect the movement of other second pushing parts, and the six sleeves are all attached to the medullary cavity wall, all the first pushing parts are lifted out of the second pushing parts, and all the second pushing parts stop working. Then the screw is continuously screwed into the lower handle body to realize the connection and fixation of the upper handle body and the lower handle body; finally, the bone cement is injected through the micropores on the sleeve to further fill the gap, so that the whole prosthesis is more stable.

[0050] In summary, the femoral stem prosthesis is improved in the application, which can make the femoral stem neck actively and effectively adapt to irregular medullary cavities, especially can closely fit and support the key lateral cortex of the femur, reduce the gap between the femoral stem and the medullary cavity, and enhance the overall stability of the femoral stem prosthesis.

[0051] In the description of the application, it should be understood that the orientation words such as "front, back, upper, lower, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship are generally based on the orientation or position relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0052] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used herein to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0053] In addition, it should be noted that the use of "first", "second" and the like to define parts only facilitates the differentiation of the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as a limitation on the scope of protection of the application.

[0054] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A femoral stem prosthesis, characterized by, The femoral stem (1) comprises an upper stem body (10) and a lower stem body (11), the upper stem body (10) is partially hollow inside, the top of the upper stem body (10) is provided with a circular first opening (100), and the side of the upper stem body (10) is uniformly provided with six second openings (101); The expansion component (2) is arranged in the hollow inside of the upper stem body (10), and the expansion component (2) comprises: The screw (20) is provided with a second thread (200) at the lower part, The rotating disc (21) is provided with a third thread (210) at the middle part, the third thread (210) is engaged with the second thread (200), the rotating disc (21) is uniformly provided with six first guide rails (211) on the upper part, The first pushing part (22) is inserted into the first guide rail (211), The track component (23) is arranged at the lower part of the rotating disc (21), the middle part of the track component (23) is a rectangular hole, and the inner walls of the two sides of the track component (23) are symmetrically provided with ratchets (230), The second pushing part (24) is arranged inside the track component (23), the two sides of the second pushing part (24) are symmetrically provided with first recesses (240), the first recesses (240) are provided with pawl parts (241), the pawl parts (241) are engaged with the ratchets (230), the upper part of the second pushing part (24) is provided with a circular third opening (244), the side of the second pushing part (24) is provided with a fourth opening (245), and the inside of the second pushing part (24) is provided with a first hole (246); The sleeve (3) is sleeved on the neck of the femoral stem (1) and comprises: The third pushing part (30) is a cylindrical body with a height and a diameter matched with the third opening (244), The fourth pushing part (32) is an elastic component with an arc shape, The fifth pushing part (33) is arranged between the fourth pushing part (32) and the sleeve (3), and the fifth pushing part (33) is connected with the sleeve (3) and extends out of the second opening (101). The diameter of the first opening (100) is consistent with the diameter of the screw (20), the screw (20) extends into the femoral stem (1) from the first opening (100), the inside of the upper stem body (10) is provided with a first thread (12), and the first thread (12) is engaged with the second thread (200).

2. A femoral stem prosthesis according to claim 1, wherein, The inside of the lower stem body (11) is also provided with the first thread (12), the lower stem body (11) is replaceable and has different specifications and sizes, and the screw (20) can connect the upper stem body (10) and the lower stem body (11).

3. A femoral stem prosthesis according to claim 2, wherein, ​ 4. The femoral stem prosthesis of claim 1 wherein, The first guide rail (211) is circular arc-shaped and penetrates the rotating disc (21), the first pushing part (22) comprises an upper pushing block (220) and a lower pushing block (221), the upper pushing block (220) and the lower pushing block (221) are cylindrical, the diameter of the upper pushing block (220) is greater than that of the lower pushing block (221), the diameter of the lower pushing block (221) is consistent with the track width of the first guide rail (211), the height of the lower pushing block (221) is greater than that of the first guide rail (211), and the diameter of the lower pushing block (221) is consistent with that of the third opening (244).

5. The femoral stem prosthesis of claim 1 wherein, The second pushing part (24) is symmetrically provided with first fixing blocks (242) on both sides, the first fixing blocks (242) are provided with rotating rods (243) in the middle, and the pawl parts (241) are hingedly connected with the first fixing blocks (242) through the rotating rods (243).

6. The femoral stem prosthesis of claim 1 wherein, The middle part of the first hole (246) is a semicircular hole with a height greater than that of the fourth pushing part (32), the left side is a rectangular hole, the right side is a rectangular hole penetrating to the fourth opening (245), and the first hole (246) is connected with the third opening (244) and the fourth opening (245).

7. The femoral stem prosthesis of claim 1 wherein, The sleeve (3) is composed of six sleeve units, the sleeve (3) has a certain ductility, the top of the sleeve (3) is provided with a micropore (34), the side, away from the sleeve (3), of the fourth pushing part (32) is connected with a first connecting part (31), and the third pushing part (30) is arranged on the top of the fourth pushing part (32).

8. A femoral stem prosthesis according to claim 7, wherein, The combination of the third pushing part (30), the first connecting part (31), the fourth pushing part (32) and the fifth pushing part (33) is placed in the first hole (246).

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