CN116439882A - Reverse hip joint prosthesis system capable of reducing dislocation risk - Google Patents

Abstract

The application relates to a reverse hip joint prosthesis system capable of reducing dislocation risk, which comprises a femur stem, a femur cup, a polyethylene lining, a ball head and an acetabular cup which are sequentially arranged from a femur to a hip joint; the femur cup is installed on the femur handle, the polyethylene lining is installed inside the femur cup, the ball head comprises an arc supporting surface and a connecting surface, the connecting surface is connected with the acetabulum cup, the relative positions of the ball head and the acetabulum cup are fixed, bone screw holes are formed in the acetabulum cup, the acetabulum cup is fixed in the hip joint through bone screws, gaps exist between the acetabulum cup and the ball head, the wall thickness sum of the femur cup and the polyethylene lining is smaller than the gap between the acetabulum cup and the ball head, the femur cup and the polyethylene lining are constantly supported by the ball head, and rotate around the spherical center of the ball head in the gap between the acetabulum cup and the ball head. The ball joint and the femur cup are in constant contact with the acetabulum cup, the polyethylene lining is uniformly stressed all the time, and the dislocation risk of the hip joint is reduced in a reasonable movement range.

Description

A reverse hip prosthesis system that reduces the risk of dislocation

technical field

This application relates to the field of medical devices, in particular to a reverse hip joint prosthesis system that can reduce the risk of dislocation.

Background technique

Dislocation is one of the most common complications of total hip arthroplasty (THA). Specifically, dislocation rates can be as high as 10% after primary surgery and as high as 25% after revision surgery. Recurrent instability is a difficult problem to overcome, although traditional approaches include implant repositioning, use of raised marginal liners, removal of impingement sources, trochanter advancement, and abductor repair. Surgical stabilization using these traditional methods is unpredictable, with a success rate of only 60 - 80%, depending on the type of dislocation, etiology, and surgical technique used.

At present, the product structure of traditional hip joint prosthesis mainly includes four parts: femoral stem, ball head, polyethylene liner and acetabular cup. The extrusion force of the acetabular cup is concentrated on a certain part, causing the ball head and the acetabular cup to be unable to maintain constant contact, resulting in concentrated wear of a certain part of the polyethylene lining, shortening the service life of the hip prosthesis, and improving the stability of the hip prosthesis Poor, there is a risk of acetabular dislocation.

Contents of the invention

In order to prolong the service life of the hip joint prosthesis within a reasonable range of motion, improve the stability of the hip joint, and reduce the risk of hip dislocation, the present application provides a reverse hip joint prosthesis system that can reduce the risk of dislocation.

A reverse hip joint prosthesis system that can reduce the risk of dislocation provided by this application adopts the following technical scheme:

A reverse hip prosthesis system that can reduce the risk of dislocation, including a femoral stem, femoral cup, polyethylene liner, ball head and acetabular cup that are arranged sequentially from the femur to the hip joint;

The femoral cup is installed on the femoral stem, the polyethylene liner is installed inside the femoral cup,

The ball head includes an arc support surface and a connection surface, the connection surface is connected to the acetabular cup, the relative position of the ball head and the acetabular cup is fixed, and bone screws are provided on the acetabular cup holes, the acetabular cup is fixed in the hip joint by bone screws,

There is a gap between the acetabular cup and the ball head, and the wall thickness sum of the femoral cup and the polyethylene liner is smaller than the gap between the acetabular cup and the ball head, and the femoral The cup and the polyethylene liner are constantly supported by the head and rotate about the center of the head in the gap between the acetabular cup and the head.

By adopting the above-mentioned technical scheme, the hip joint prosthesis system is reversed, and the original force between the ball head and the acetabular cup is transformed into the force between the ball head and the femoral cup. The acetabular cup remains relatively fixed, so whether in the normal range of motion or when standing or squatting, the ball head can maintain constant contact with the femoral cup and acetabular cup; this setting not only reduces the squeeze on the acetabular cup Compression reduces the high contact stress of the hip joint, allowing wear to be evenly distributed across the contact surface of the polyethylene liner while minimizing edge loading. Moreover, the uneven wear of the polyethylene lining will aggravate the generation of polyethylene particles, and these debris particles can produce different degrees of macrophage reactions in the body, resulting in bone resorption, osteolysis, and aseptic loosening around the prosthesis , ensuring the wear uniformity of the polyethylene lining, and reducing the wear rate of the polyethylene lining have great significance for the use effect and service life of the hip joint prosthesis.

Optionally, the bottom of the femoral cup is integrally formed with a femoral neck, and the end of the femoral stem is provided with a jack that fits with the femoral neck, and the femoral neck fits with the taper of the jack;

The femoral neck is in the shape of a flat column with a smooth transition edge, the thickness of the femoral neck is 8-13mm, and the width is 10-15mm.

By adopting the above technical scheme, the femoral neck adopts a flat columnar shape, which is easy to operate during surgery and has minimal trauma to human tissue. The flat columnar femoral neck prevents the relative rotation between the femoral cup and the femoral stem; the thickness of the femoral neck is designed to be 8-13mm. The width is designed to be 10-15mm, which can minimize the obstruction caused by the femoral neck to the rotation of the femoral stem on the basis of ensuring the support strength of the femoral neck.

Optionally, the diameter of the acetabular cup is 50-72 mm, the diameter of the ball head is 22-36 mm, and the diameter of the femoral cup is 10-12 mm smaller than the diameter of the acetabular cup.

By adopting the above technical scheme, a reasonable gap is reserved between the acetabular cup and the femoral cup, and the probability of blocking between the femoral cup and the acetabular cup is reduced.

Optionally, an insertion portion is integrally formed at the inner apex of the acetabular cup, and an insertion hole taper-fitted with the insertion portion is opened on the connection surface of the ball head.

By adopting the above-mentioned technical solution, the insertion part is mated with the ball head, so that the ball head and the acetabular cup remain relatively fixed, and the replacement of the ball head is facilitated.

Optionally, the inner surface of the polyethylene liner is a smooth hemispherical surface, and the outer surface of the polyethylene liner is integrally formed with a supporting part, a connecting part and a limiting part; from one end away from the ball head to The end close to the ball head is successively a supporting part, a connecting part and a limiting part;

External threads are processed on the connecting part, and the limiting part includes a number of limiting blocks arranged on the outer wall of the polyethylene lining, and the limiting blocks are arranged at intervals around the axis of the polyethylene lining. The inner wall of the femoral cup is provided with an internal thread and a limiting sinker matched with the limiting block.

By adopting the above technical scheme, the connecting part and the femoral cup are screwed together, and the connection is convenient. After the connecting part and the femoral cup are connected, the limiting block sinks into the limiting sinker, reducing the probability of relative rotation between the polyethylene liner and the femoral cup , the connection part is located in the middle of the polyethylene liner, and the limit part is located at the opening end of the polyethylene liner to ensure that each part of the polyethylene liner fits evenly with the inner surface of the femoral stem. When moving, the polyethylene Uniform stress on liner and femoral cup.

Optionally, the connecting portion is located outside the supporting portion, there is a certain gap between the connecting portion and the supporting portion, a number of notches are opened on the connecting portion, and one end of each notch passes through the connecting part.

By adopting the above technical solution, several notches provide a certain deformation capacity for the connecting part. When the connecting part is deformed, it can be installed more closely with the femoral cup. At the same time, it can make the polyethylene lining have a certain tension and reduce the polyethylene lining. The probability.

Optionally, several capillary structures are opened on the inner surface of the polyethylene lining, and the several capillary structures are uniformly distributed around the axis of the polyethylene lining.

By adopting the above technical scheme, several capillary structures form the inner surface of the polyethylene lining and maintain a relatively smooth and humid environment, ensuring the smooth rotation between the ball head and the polyethylene lining, making the human body more flexible and slowing down the damage to the polyethylene lining. Abrasion caused by polyethylene lining.

Optionally, several serrated grooves are processed on both sides of the femoral stem, and the extension direction of the several serrated grooves is perpendicular to the length direction of the femoral stem.

By adopting the above technical solution, the setting of the serrated groove can increase the friction force between the femoral stem and the femoral head of the human body, and reduce the probability of the femoral stem prolapse.

In summary, the present application includes at least one of the following beneficial technical effects:

1. This application realizes the reverse setting of the hip joint prosthesis by adding the femoral cup, keeping the ball head and the acetabular cup relatively fixed, and the acetabular cup and the femoral cup surround the ball head, so that the ball head can be connected with the acetabular cup and The femoral cup maintains constant contact, reducing the risk of dislocation; during human activities, the force can be consistently and uniformly placed on the inner surface of the polyethylene liner, reducing the high contact stress of the hip joint and minimizing the edge load, which also reduces the risk of dislocation;

2. The setting of the limiting part can reduce the probability of relative rotation between the polyethylene liner and the femoral cup;

3. Several capillary structures arranged on the inner surface of the polyethylene lining can make the inner surface of the polyethylene lining form and maintain a smooth and moist environment, and ensure the smooth rotation of the ball head and the polyethylene lining.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the present application.

Fig. 2 is a schematic cross-sectional view of the present application.

Explanation of reference signs: 1, femoral stem; 11, socket; 12, serrated groove; 2, femoral cup; 21, limit sink; 22, second step; 3, polyethylene lining; 31, capillary structure ; 32, support portion; 33, connection portion; 331, external thread; 332, notch; 34, limit portion; 341, limit block; 35, first step; 4, ball head; 41, arc support surface; 42. Connection surface; 43. Insertion hole; 5. Acetabular cup; 51. Bone screw hole; 52. Insertion part; 6. Femoral neck.

Detailed ways

The present application will be described in further detail below in conjunction with accompanying drawings 1-2.

The embodiment of the present application discloses a reverse hip joint prosthesis system that can reduce the risk of dislocation. Referring to FIG. 1 , the reverse hip joint prosthesis system that can reduce the risk of dislocation includes a femoral stem 1 , a femoral cup 2 , a polyethylene liner 3 , a ball head 4 and an acetabular cup 5 arranged sequentially from the femur to the hip joint. The femoral cup 2 is mounted on the femoral stem 1 , and the polyethylene liner 3 is detachably connected to the inside of the femoral cup 2 . The acetabular cup 5 is provided with several bone screw holes 51, and the acetabular cup 5 is fixed in the hip joint of the human body through the bone screws. The ball head 4 includes an arc support surface 41 and a connection surface 42 , the connection surface 42 is connected with the acetabular cup 5 to keep the ball head 4 and the acetabular cup 5 relatively fixed. The ball head 4 is made of wear-resistant and corrosion-resistant materials such as ceramics or cobalt-chromium-molybdenum alloy materials.

Both the acetabular cup 5 and the femoral cup 2 are in the shape of a hemispherical shell, and there is a gap between the acetabular cup 5 and the ball head 4 , which is greater than the sum of the wall thicknesses of the polyethylene liner 3 and the femoral cup 2 . When the human body performs daily activities, the femoral cup 2 and the polyethylene liner 3 are constantly supported by the ball head 4, and the force of the femoral stem 1 will be fully and uniformly applied to the polyethylene liner 3, reducing the height of the hip joint. The contact stress reduces the probability of the femoral cup 2 coming out of the acetabular cup 5 . Due to the reverse hip joint prosthesis system of the present application, the wear is evenly distributed on the contact surface of the polyethylene liner 3, which can reduce the probability of accelerated generation of polyethylene particles due to uneven wear, thereby causing different degrees of macrophages Cellular reaction, leading to bone resorption, osteolysis, resulting in aseptic loosening around the prosthesis.

The femoral cup 2 is detachably connected to the femoral stem 1, the bottom of the femoral stem 1 is integrally formed with a femoral neck 6, and the end of the femoral stem 1 is provided with a socket 11 that matches the femoral neck 6, and the femoral neck 6 and the socket 11 are tapered. . The ball head 4 and the acetabular cup 5 can also be detachably connected. Specifically, the inner wall of the apex of the acetabular cup 5 is integrally formed with an insertion part 52, and the connection surface 42 of the ball head 4 is provided with a taper fitting with the insertion part 52. socket.

The acetabular cup 5 is provided with different sizes according to different human development conditions. When in use, the femoral cup 2 and the ball head 4 need to be matched and replaced according to the size of the acetabular cup 5 used. The diameter of the acetabular cup 5 is 50-72mm, the diameter of the ball head 4 is 22-36mm, and the diameter of the femoral cup 2 is 10-12mm smaller than that of the acetabular cup 5 .

In order to facilitate the hip joint replacement operation, the femoral neck 6 is preferably in the shape of a flat column with smooth edges. In order to ensure the supporting strength of the femoral neck 6 and avoid the fracture of the femoral neck 6 as much as possible to reduce the blocking of the rotation range of the femoral cup 2, the thickness of the femoral neck 6 is 8-13mm, and the width is 10-15mm. Preferably, the femoral neck 6 of the present application has a thickness of 11 mm and a width of 13 mm.

The polyethylene liner 3 is detachably connected to the inner surface of the femoral cup 2 . The inner surface of the polyethylene liner 3 is a smooth hemispherical surface, and the outer surface of the polyethylene liner 3 is integrally formed with a supporting portion 32 , a connecting portion 33 and a limiting portion 34 . The supporting part 32 , the connecting part 33 and the limiting part 34 are sequentially arranged from an end close to the ball head 4 to an end far away from the ball head 4 . The support part 32 is used to realize close contact with the inner wall of the femoral cup 2, and the connecting part 33 is processed with an external thread 331, and the inner wall of the femoral cup 2 is processed with an internal thread that is threadedly matched with the connecting part 33, so as to realize the connection with the femoral cup 2. Quick connection. The limiting portion 34 is used to prevent the polyethylene liner 3 and the femoral cup 2 from rotating relative to each other during normal human activities. Specifically, the limiting portion 34 includes a plurality of limiting blocks 341 arranged at intervals around the axis of the polyethylene liner 3 , and a plurality of limiting sinks 21 corresponding to the limiting blocks 341 are opened on the inner wall of the femoral cup 2 . In order to ensure that all parts of the polyethylene liner 3 are kept in contact with the inner wall of the femoral cup 2 and reduce the probability that the polyethylene liner 3 shakes in the femoral cup 2, the limiting part 34 is located in the middle of the polyethylene liner 3, The limiting portion 34 is located at the opening end of the polyethylene liner 3 .

The connecting portion 33 is located on the outside of the supporting portion 32, and there is a certain gap between the connecting portion 33 and the supporting portion 32. The connecting portion 33 is provided with a number of notches 332, and one end of each notch 332 runs through the connecting portion 33, and several notches 332 surround the polyethylene The axis of the inner liner 3 is evenly arranged on the connecting portion 33, so that the connecting portion 33 has a certain deformation capacity, which is convenient for installing the polyethylene inner liner 3 in a squeezed state inside the femoral cup 2, and further reduces the polyethylene liner 3 prolapse The probability. A first step 35 is formed between the connecting part 33 and the supporting part 32, and a second step 22 matching the first step 35 is formed on the inner wall of the femoral cup 2 to ensure the contact between the outer surface of the polyethylene liner 3 and the femoral cup 2. Inner surface fits snugly.

The inner surface of the polyethylene lining 3 is provided with a plurality of capillary structures 31 , and the plurality of capillary structures 31 are evenly distributed around the axis of the polyethylene lining 3 . Specifically, the capillary structure 31 is a storage tank opened on the inner surface of the polyethylene liner 3 . The capillary structure 31 keeps the inner surface of the polyethylene liner 3 in a smooth and moist environment, reduces the frictional resistance between the ball head 4 and the polyethylene liner 3, and enables the femoral stem 1 and the polyethylene liner 3 to surround the ball head 4 smoothly Rotation slows down the period of wear and tear of the polyethylene liner 3, and improves flexibility during human activities.

After the reverse hip joint prosthesis of the present application is implanted into the human body, in order to increase the connection stability between the femoral stem 1 and the human femur, several serrated grooves 12 are processed on both sides of the femoral stem 1, and the extension direction of the several serrated grooves 12 is consistent with the The length direction of the femoral stem 1 is vertical.

The implementation principle of a reverse hip joint prosthesis system that can reduce the risk of dislocation in the embodiment of the present application is: when the human body performs a reasonable range of activities or when standing or squatting at a large scale, the ball head 4, the femoral cup 2, and the acetabulum The cups 5 can maintain constant contact, which reduces the extrusion of the acetabular cup 5, reduces the high contact stress of the hip joint, and makes the wear evenly distributed on the contact surface of the polyethylene liner 3, while minimizing the edge load. Within a reasonable range of motion, the service life of the hip prosthesis is extended, the stability of the hip joint is improved, and the risk of hip dislocation is reduced.

All of the above are preferred embodiments of the application, and are not intended to limit the protection scope of the application. Therefore, all equivalent changes made according to the structure, shape, and principle of the application should be covered by the protection scope of the application. Inside.

Claims (8)

1. A reverse hip joint prosthesis system that can reduce the risk of dislocation is characterized in that: it comprises a femoral stem (1), a femoral cup (2), a polyethylene liner (3), Ball head (4) and acetabular cup (5); The femoral cup (2) is installed on the femoral stem (1), the polyethylene liner (3) is installed inside the femoral cup (2), The ball head (4) includes an arc support surface (41) and a connection surface (42), the connection surface (42) is connected to the acetabular cup (5), and the ball head (4) is connected to the acetabular cup (5). The relative position of the acetabular cup (5) is fixed, the acetabular cup (5) is provided with bone screw holes (51), and the acetabular cup (5) is fixed in the hip joint by bone screws, There is a gap between the acetabular cup (5) and the ball head (4), and the sum of the wall thicknesses of the femoral cup (2) and the polyethylene liner (3) is smaller than that of the acetabular cup ( 5) The gap between the ball head (4), the femoral cup (2) and the polyethylene liner (3) are constantly supported by the ball head (4), and around the ball head The ball center of (4) rotates in the gap between the acetabular cup (5) and the ball head (4). 2. The reverse hip joint prosthesis system capable of reducing the risk of dislocation according to claim 1, characterized in that: the bottom of the femoral cup (2) is integrally formed with a femoral neck (6), and the femoral stem (1) The end is provided with a socket (11) matching with the femoral neck (6), and the femoral neck (6) is taper-fitted with the socket (11); The femoral neck (6) is flat columnar with a smooth transition edge, the thickness of the femoral neck (6) is 8-13mm, and the width is 10-15mm. 3. The reverse hip joint prosthesis system capable of reducing the risk of dislocation according to claim 1, characterized in that: the diameter of the acetabular cup (5) is 50-72mm, and the diameter of the ball head (4) The diameter of the femoral cup (2) is 10-12mm smaller than that of the acetabular cup (5). 4. The reverse hip joint prosthesis system capable of reducing the risk of dislocation according to claim 1, characterized in that: the inner apex of the acetabular cup (5) is integrally formed with an insertion part (52), the The connection surface (42) of the ball head (4) is provided with an insertion hole (43) which is taper matched with the insertion portion (52). 5. The reverse hip joint prosthesis system capable of reducing the risk of dislocation according to claim 1, characterized in that: the inner surface of the polyethylene lining (3) is a smooth hemispherical surface, and the polyethylene lining (3) The outer surface of (3) is integrally formed with a supporting part (32), a connecting part (33) and a limiting part (34); from an end far away from the ball head (4) to an end close to the ball head (4) The supporting part (32), the connecting part (33), and the limiting part (34) are in order; External threads (331) are processed on the connecting portion (33), and the limiting portion (34) includes several limiting blocks (341) arranged on the outer wall of the polyethylene liner (3). Blocks (341) are arranged at intervals around the axis of the polyethylene liner (3), and the inner wall of the femoral cup (2) is provided with an internal thread and a limit sink that cooperates with the limit block (341) (twenty one). 6. The reverse hip joint prosthesis system capable of reducing the risk of dislocation according to claim 5, characterized in that: the connecting part (33) is located outside the supporting part (32), and the connecting part (33) ) and the support portion (32), there are some gaps (332) on the connection portion (33), and one end of each of the gaps (332) passes through the connection portion (33). 7. The reverse hip joint prosthesis system capable of reducing the risk of dislocation according to claim 1, characterized in that: the inner surface of the polyethylene lining (3) is provided with several capillary structures (31), and several The capillary structures (31) are evenly distributed around the axis of the polyethylene lining (3). 8. The reverse hip joint prosthesis system capable of reducing the risk of dislocation according to claim 1, characterized in that: several serrated grooves (12) are processed on both sides of the femoral stem (1), and several serrated grooves The extension direction of (12) is perpendicular to the length direction of the femoral stem (1).