Hip joint femoral stem prosthesis compounded with proximal femoral locking screw

Abstract

The utility model relates to a hip joint femoral stem prosthesis compounded with a proximal femoral locking screw. The hip joint femoral stem prosthesis is provided with a femoral stem body. The femoral stem body is provided with two threaded through holes which are not communicated with each other, projections of the threaded through holes on an XZ plane are staggered, a locking screw is arranged in each threaded through hole and comprises a screw head and a screw rod, the screw head is provided with head threads, the screw rod is provided with rod threads, the threaded through holes are provided with head sinking grooves, and the head sinking grooves are communicated with the threaded through holes. Sinking groove threads are arranged on the side wall of the head sinking groove, through hole threads are arranged in the threaded through hole, and one end of each locking screw penetrates through and extends out of the threaded through hole through thread fit of the rod threads and the through hole threads to be connected with the thighbone. The other end of each locking screw extends into the head countersunk groove through thread fit of the head threads and the countersunk groove threads and is fixedly connected with the femoral stem, and the locking screws lock the femoral stem body and meanwhile lock the thighbone through thread fit. The device is ingenious in structure, convenient and efficient.

Description

Technical Field

[0001] The utility model relates to the field of hip femoral stem prostheses, and particularly relates to a hip femoral stem prosthesis combined with a proximal femoral locking screw. Background Art

[0002] With the continuous development of medical technology, total hip arthroplasty has become an important means for treating hip diseases. However, postoperative prosthesis loosening is one of the main problems faced by total hip arthroplasty. Existing femoral stem prostheses mainly rely on bone cement or screws for fixation, but due to reasons such as materials and designs, their long-term stability is not ideal. Therefore, developing a new type of hip femoral stem prosthesis to improve its stability after installation has important clinical significance and practical value.

[0003] For complex hip diseases, such as Crowe type IV developmental dysplasia of the hip (DDH), due to the abnormal femoral anteversion angle of patients, and many patients need to undergo subtrochanteric osteotomy. Therefore, when performing total hip arthroplasty, a prosthesis with an adjustable anteversion angle needs to be prepared. However, during the long-term use of the prosthesis, nonunion of the femoral osteotomy site occurs, and the gap becomes larger. Once proximal loosening of the prosthesis occurs, the consequence may be revision surgery, which will increase the operation time, further increase the incidence of complications, and greatly reduce the quality of life of the patient, which is very inconvenient. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a hip femoral stem prosthesis combined with a proximal femoral locking screw, which effectively solves the problem that the femoral stem prosthesis is prone to loosening after installation, greatly improves the connection strength, stability and firmness between the femoral stem body and the femur, and has a clever structure, and is convenient and practical.

[0005] The technical solution for achieving the object of the present utility model is as follows: The present utility model has a femoral stem body; two non-communicating threaded through holes are provided on the femoral stem body, and the projections of each threaded through hole on the XZ plane are staggered and symmetrically arranged. A locking screw is disposed in each threaded through hole. The locking screw includes a screw head and a screw rod portion. A head thread is provided on the screw head, and a rod thread is provided on the screw rod portion. A head counterbore for the screw head to extend into is provided on the threaded through hole. A counterbore thread that can be threadedly engaged with the head thread is provided on the side wall of the head counterbore. A through hole thread that is threadedly engaged with the rod thread is provided in the threaded through hole. One end of each locking screw passes through and extends out of the threaded through hole through the threaded engagement between the rod thread of the screw rod portion and the through hole thread in the threaded through hole and then is connected to the femur. The other end of each locking screw extends into the head counterbore through the threaded engagement between the head thread of the screw head and the counterbore thread in the head counterbore and is fixedly connected to the femoral stem body. Each locking screw locks the femoral stem body through threaded engagement and locks the femur at the same time.

[0006] Further, the included angle of the projections of each locking screw on the XY plane is 90°, the included angle of the projections of each locking screw on the XZ plane is 60°, the included angle between each locking screw and the axis of the femoral stem body on the XZ plane is 30°, and the included angle between each locking screw and the axis of the femoral stem body on the YZ plane is 30°.

[0007] Further, the femoral stem body includes a stem body and a connecting portion. The stem body and the connecting portion are integrally formed. The stem body is conical. One end of each threaded through hole is provided on the upper end surface of the stem body, and the other end of each threaded through hole is provided on the side wall of the stem body. One end of each locking screw extends into the stem body from the upper end surface of the stem body and extends out from the side wall of the stem body and then is connected to the femur.

[0008] Further, a plurality of ridges are provided on the side wall of the stem body, and each ridge is circumferentially distributed on the outer wall of the stem body along the axis of the stem body.

[0009] Further, there are eight ridges on the side wall of the stem body.

[0010] The utility model has positive effects: (1) In the utility model, two through threaded holes with symmetrical projections are arranged on the femoral stem body, and locking screws are arranged in each through threaded hole. The screw rod parts on each locking screw pass through and extend out of the through threaded hole through the thread of the rod part and the through hole thread in the through threaded hole and are connected to the femur. The screw head parts on each locking screw ensure the firmness and stability of the connection between each locking screw rod and the femoral stem body through the cooperation of the head thread and the counterbore thread. At the same time, when each locking screw is locked and connected to the femoral stem body, the femoral stem body and the femur are also locked and connected, effectively avoiding the phenomenon that the screw loosens due to long-term stress in the prior art, ensuring the firmness and strength of the connection between the locking screw, the femoral stem body, and the femur. The structure is ingenious, efficient, and convenient.

[0011] (2) In the utility model, specific angles are set for each locking screw in the XY plane, XZ plane, and YZ plane. Combining with the anatomical structure and mechanical properties of the human femur, the screws can disperse stress more evenly after implantation, achieving a powerful supporting and fixing effect, and further preventing loosening between the femoral stem body and the femur. It is safe and practical.

[0012] (3) In the utility model, the handle body is set to be conical, which can ensure the axial stability during the connection of the femoral stem.

[0013] (4) In the utility model, multiple ridges are arranged on the side wall of the handle body, which can effectively ensure the rotational stability of the handle body on the femoral stem. It is safe and practical. Description of the Drawings

[0014] In order to make the content of the utility model easier to be clearly understood, the following further details the utility model according to specific embodiments and in combination with the drawings, where

[0015] Figure 1 is the front view of the overall structure of the hip joint femoral stem prosthesis with a composite femoral proximal locking screw in the utility model;

[0016] Figure 2 is the top view of the overall structure of the hip joint femoral stem prosthesis with a composite femoral proximal locking screw in the utility model;

[0017] Figure 3 is the left view of the overall structure of the hip joint femoral stem prosthesis with a composite femoral proximal locking screw in the utility model;

[0018] Figure 4 is the schematic diagram of the overall structure of the femoral stem body in the utility model;

[0019] Figure 5 is the schematic diagram of the overall structure of the locking screw in the utility model;

[0020] Figure 6 It is a cross-sectional view of the overall structure of the femoral stem body in the utility model;

[0021] Figure 7 It is Figure 6 an enlarged view of part A in Specific embodiments

[0022] See Figures 1 to 7 , the utility model relates to a hip femoral stem prosthesis with a composite proximal femoral locking screw 2, having a femoral stem body 1; two non-communicating threaded through holes 13 are provided on the femoral stem body 1, and the projections of each threaded through hole 13 on the XZ plane are staggered and symmetrically arranged. A locking screw 2 is disposed in each threaded through hole 13. The locking screw 2 includes a screw head 21 and a screw rod portion 22. A head thread 23 is provided on the screw head 21, and a rod thread 24 is provided on the screw rod portion 22. A head counterbore 14 for the screw head 21 to extend into is provided on the threaded through hole 13. A counterbore thread 15 that can be threadedly engaged with the head thread 23 is provided on the side wall of the head counterbore 14. A through hole thread 16 that is threadedly engaged with the rod thread 24 is provided in the threaded through hole 13. One end of each locking screw 2 passes through and extends out of the threaded through hole 13 through the threaded engagement between the rod thread 24 of the screw rod portion 22 and the through hole thread 16 in the threaded through hole 13 and is connected to the femur. The other end of each locking screw 2 extends into the head counterbore 14 through the threaded engagement between the head thread 23 of the screw head 21 and the counterbore thread 15 in the head counterbore 14 and is fixedly connected to the femoral stem body 1. Each locking screw 2 locks the femoral stem body 1 while locking the femur through threaded engagement.

[0023] The included angle of the projections of each locking screw 2 on the XY plane is 90°, the included angle of the projections of each locking screw 2 on the XZ plane is 60°, the included angle between each locking screw 2 and the axis of the femoral stem body 1 on the XZ plane is 30°, and the included angle between each locking screw 2 and the axis of the femoral stem body 1 on the YZ plane is 30°.

[0024] The femoral stem body 1 includes a stem body 11 and a connecting portion 12. The stem body 11 and the connecting portion 12 are integrally formed. The stem body 11 is conical with a taper of 5°. One end of each threaded through hole 13 is provided on the upper end surface of the stem body 11, and the other end of each threaded through hole 13 is provided on the side wall of the stem body 11. One end of each locking screw 2 extends into the stem body 11 from the upper end surface of the stem body 11 and extends out from the side wall of the stem body 11 and is connected to the femur.

[0025] A plurality of ridges 3 are provided on the side wall of the stem body 11, and each ridge 3 is circumferentially distributed on the outer wall of the stem body 11 along the axis of the stem body 11.

[0026] Eight ridges 3 are provided on the side wall of the handle body 11.

[0027] The working principle of the present utility model: During the use of the present utility model, one end of each locking screw 2 passes through and extends out of the threaded through hole 13 through the thread fit between the rod thread 24 of the screw rod part 22 and the through hole thread 16 in the threaded through hole 13 and is connected to the femur. The other end of each locking screw 2 extends into the head counterbore 14 through the thread fit between the head thread 23 of the screw head 21 and the counterbore thread 15 in the head counterbore 14 and is fixedly connected to the femoral stem. Each locking screw 2 locks the femoral stem body 1 while locking the femur through thread fit;

[0028] Traditional femoral stem prostheses usually use single-direction screws or rely on bone cement for fixation. The present utility model adopts a composite proximal femoral locking screw 2 design, and the directions of the two locking screws 2 and the directions with respect to the axis of the femoral stem body 1 incorporate the anatomical structure and mechanical properties of the human femur, enabling the screws to more evenly disperse stress after implantation and providing a stronger support and fixation effect;

[0029] Since the hip joint bears complex forces and torques during daily activities, a stable fixation system is crucial for the long-term stability of the prosthesis and the rehabilitation of the patient. Based on this requirement, by optimizing the number, direction, and angle of the locking screws 2, a stronger fixation effect is achieved, thereby effectively preventing prosthesis loosening.

[0030] During the installation process, first implant the femoral stem body 1 into the patient's body, and then fix the femoral stem body 1 to the femur through the locking screws 2. When the locking screws 2 are tightened, the cooperation between the head thread 23 and the counterbore thread 15 on the locking screws 2 and the cooperation between the rod thread 24 and the through hole thread 16 form a stable locking mechanism, thereby effectively preventing the loosening of the frame body;

[0031] The mutual cooperation and interlocking between the locking screws 2 and the femoral stem body 1 form a stable lock. This locking method not only enhances the connection strength between the locking screws 2 and the femoral stem body 1 but also prevents the loosening and displacement of the screws through mechanical interlocking. The traditional screw fixation method may loosen due to long-term stress and fatigue, while the present utility model improves the additional fixing force through mechanical interlocking and improves the overall stability of the system, enabling it to resist the influence of long-term stress and fatigue and ensuring that the frame body remains stable for a long time.

[0032] After each locking screw 2 is connected to the femoral stem body 1, the included angle of the projection of each locking screw 2 in the XY plane is 90°, the included angle of the projection of each locking screw 2 in the XZ plane is 60°, the included angle between the axis of each locking screw 2 and the femoral stem body 1 in the XZ plane is 30°, and the included angle between the axis of each locking screw 2 and the femoral stem body 1 in the YZ plane is 30°;

[0033] Through the design of the locking screw 2, the long-term stability of the hip femoral stem prosthesis is significantly improved. The locking screw 2 can disperse stress more evenly, providing a stronger support and fixation effect, thus effectively preventing postoperative prosthesis loosening. The improvement of long-term stability means that patients can resume activities earlier after surgery, reducing the risk of reoperation caused by prosthesis loosening, thereby improving the quality of life of patients.

[0034] Since the stability of the prosthesis is guaranteed, the occurrence of complications caused by prosthesis loosening is reduced. These complications may include infections around the prosthesis, bone resorption or fractures, etc. By reducing the risk of these complications, the postoperative recovery process of patients is smoother, the recovery time is shortened, and postoperative pain and discomfort are also relieved. These factors combined significantly improve the postoperative recovery effect and quality of life of patients;

[0035] In the present utility model, the design of the locking screw 2 not only considers the long-term stability of the prosthesis, but also makes the installation process simpler and faster. This design reduces the complex operations during the surgery, reduces the surgical difficulty, and thus also reduces the surgical risk. For doctors, this means that they can complete the surgery more quickly and safely; for patients, this means a shorter surgery time, less surgical trauma, and faster recovery.

[0036] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present utility model. It should be understood that the above are only specific embodiments of the present utility model and are not used to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A hip femoral stem prosthesis with a composite proximal femoral locking screw, having a femoral stem body; characterized in that: The femoral stem body is provided with two non-communicating threaded through holes, and the projections of the respective threaded through holes on the XZ plane are staggered and symmetrically arranged. A locking screw is disposed in each threaded through hole. The locking screw includes a screw head and a screw rod portion. The screw head is provided with a head thread, and the screw rod portion is provided with a rod thread. The threaded through hole is provided with a head counterbore for the screw head to extend into. The side wall of the head counterbore is provided with a counterbore thread that can be threadedly engaged with the head thread. The threaded through hole is provided with a through hole thread that is threadedly engaged with the rod thread. One end of each locking screw passes through and extends out of the threaded through hole through the threaded engagement between the rod thread of the screw rod portion and the through hole thread in the threaded through hole and then is connected to the femur. The other end of each locking screw extends into the head counterbore through the threaded engagement between the head thread of the screw head and the counterbore thread in the head counterbore and is fixedly connected to the femoral stem body. Each locking screw locks the femoral stem body while locking the femur through threaded engagement.

2. The hip femoral stem prosthesis of a composite proximal femoral locking screw according to claim 1, characterized in that: The included angle of the projections of each locking screw on the XY plane is 90°, the included angle of the projections of each locking screw on the XZ plane is 60°, the included angle between each locking screw and the axis of the femoral stem body on the XZ plane is 30°, and the included angle between each locking screw and the axis of the femoral stem body on the YZ plane is 30°.

3. The hip femoral stem prosthesis of a composite proximal femoral locking screw according to claim 2, wherein: The femoral stem body includes a stem body and a connecting portion. The stem body and the connecting portion are integrally formed. The stem body is conical. One end of each threaded through hole is disposed on the upper end surface of the stem body, and the other end of each threaded through hole is disposed on the side wall of the stem body. One end of each locking screw extends into the stem body from the upper end surface of the stem body and extends out of the side wall of the stem body and then is connected to the femur.

4. The hip femoral stem prosthesis with a composite proximal femoral locking screw according to claim 3, characterized in that: A plurality of ridges are provided on the side wall of the stem body, and each ridge is circumferentially distributed on the outer wall of the stem body along the axis of the stem body.

5. The hip femoral stem prosthesis of a composite proximal femoral locking screw according to claim 4, characterized in that: There are eight ridges on the side wall of the stem body.

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