A reverse hip prosthesis for severe acetabular defects

Abstract

The present application relates to the field of medical devices, in particular to a reverse hip joint prosthesis for severe acetabular defects. The present application provides a reverse hip joint prosthesis, comprising a femoral side prosthesis and an acetabular side prosthesis, the femoral side prosthesis comprising a femoral cup and a femoral stem, the femoral cup and the femoral stem being connected by a connecting neck, the acetabular side prosthesis comprising an acetabular head and a bone body fitting part, the acetabular head and the bone body fitting part being connected by a head support, the femoral cup and the acetabular head being matched. The reverse hip joint prosthesis provided by the present application is used to help the subject to achieve the best surgical effect.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and in particular to a reverse hip joint prosthesis for severe acetabular defects. Background Technology

[0002] Currently, revision hip surgery for acetabular defects primarily relies on the Paprosky classification, with the key to successful treatment being the restoration of stable fixation of the acetabular cup and remaining acetabular bone. Depending on the severity and location of the defect, common acetabular reconstruction strategies include: raising the center of rotation, elliptical cup reconstruction, trabecular bone reconstruction cups with electrical control, bipolar cups, structural bone grafting, cemented cups, uncemented cups (including the extra-large Jumbo cup), acetabular reinforcement materials (such as augmentation blocks, cup cages, etc.), and cup-in-cup or cup-by-cup techniques. For extremely severe bone defects, 3D-printed hemipelvic prostheses are also used. All these techniques aim to restore an acetabular structure closely resembling the human body's structure, requiring extensive experience to select the appropriate surgical strategy and demanding a high level of surgical skill.

[0003] The existing acetabular reconstruction techniques have the following problems:

[0004] (1) Reconstructing the acetabulum on the pelvic side is difficult and requires advanced techniques:

[0005] Reconstructing the acetabulum on the pelvic side with severe bone defects requires numerous implants, such as autologous bone, allogeneic bone, bone cement, or metal implants, to obtain a hemispherical surface with relative strength. This procedure demands extremely high levels of surgeon experience and surgical skill, and increases the risk of infection and surgical costs.

[0006] (2) Poor stability of the reconstructed hip joint:

[0007] Due to the influence of residual bone, the size and direction of the acetabulum are limited, and the compromised position of the acetabulum often cannot provide sufficient stability. Secondly, the reconstructed acetabulum is often large, even using a jumbo cup, resulting in an excessively large ball-acetabulum diameter ratio, limited range of motion of the hip joint, and a relatively increased risk of dislocation due to impact. Summary of the Invention

[0008] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a reverse hip joint prosthesis for severe acetabular defects, in order to solve the problems in the prior art.

[0009] To achieve the above and other related objectives, the present invention provides a reverse hip joint prosthesis, comprising a femoral prosthesis and an acetabular prosthesis. The femoral prosthesis includes a femoral cup and a femoral stem, which are connected by a connecting neck. The acetabular prosthesis includes an acetabular head and a bone-body fitting portion, which are connected by a head support. The femoral cup and the acetabular head cooperate with each other.

[0010] In some embodiments of the present invention, the contact surface of the bone body fitting portion is a rough surface.

[0011] In some embodiments of the present invention, the acetabular prosthesis includes a plurality of bone-fitting portions, at least a portion of which are used to fit one or more of the following combinations: the acetabular bone body in the ischial ramus direction, the acetabular bone body in the pubic ramus direction, or the acetabular bone body in the iliac direction.

[0012] In some embodiments of the present invention, the bone-fitting portion further includes a fitting extension portion.

[0013] In some embodiments of the present invention, the bone-fitting portion is provided with through holes.

[0014] In some embodiments of the present invention, the acetabular prosthesis further includes a pelvic fixation member that mates with the through hole.

[0015] In some embodiments of the present invention, the ball head support includes a central portion, and the acetabular ball head and each bone body fitting portion are respectively connected to the central portion.

[0016] In some embodiments of the present invention, the neck-shaft angle between the connecting neck and the femoral stem is 125-140°, the perpendicular distance from the center of the acetabular ball head to the axis of the femoral stem is 30-40 mm, and the center of the femoral cup is located on the extension line of the connecting neck.

[0017] In some embodiments of the present invention, the femoral cup is further provided with a gasket.

[0018] In some embodiments of the present invention, when the reverse hip joint prosthesis is matched to the corresponding human body part, the projection of the center of the acetabular head on the vertical axis does not fall outside the femoral cup when the hip is flexed at 110-120°, abducted at 45° to adducted at 15°, internally rotated at 30° to externally rotated at 30° when the hip is flexed at 90°, and externally rotated at 90° when the hip is extended. Attached Figure Description

[0019] Figure 1 The diagram shown is a schematic representation of the overall structure of the reverse hip joint prosthesis provided by the present invention.

[0020] Figure 2The diagram shown is an exploded view of the reverse hip joint prosthesis provided by the present invention.

[0021] Figure 3 The diagram shows a partial structural schematic of the femoral side prosthesis in the reverse hip joint prosthesis provided by the present invention.

[0022] Figure 4 The diagram shows a partial structural schematic of the femoral side prosthesis in the reverse hip joint prosthesis provided by the present invention.

[0023] Figure 5 The diagram shows a schematic of the acetabular side prosthesis structure in the reverse hip joint prosthesis provided by the present invention.

[0024] Figure 6 The diagram shows the use of the reverse hip joint prosthesis provided by the present invention.

[0025] Component designation explanation

[0026] 1. Femoral prosthesis

[0027] 11 Femoral Cup

[0028] 12 Femoral stem

[0029] 13 Connecting neck

[0030] 14 Gaskets

[0031] 2. Acetabular side prosthesis

[0032] 21 Acetabular head

[0033] 22. Bone-body apposition

[0034] 221 Fitting Extension Section

[0035] 23 Ball head support component

[0036] 231 Central Department

[0037] 24 Pelvic Fixation Components

[0038] 3. Femur

[0039] 4. Pelvis Detailed Implementation

[0040] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0041] Please see Figures 1-6It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0042] See Figures 1-5 This invention provides a reverse hip joint prosthesis, comprising a femoral prosthesis 1 and an acetabular prosthesis 2. The femoral prosthesis 1 includes a femoral cup 11 and a femoral stem 12, which are connected by a connecting neck 13. The acetabular prosthesis 2 includes an acetabular ball head 21 and a bone-body fitting portion 22, which are connected by a ball head support 23. The femoral cup 11 and the acetabular ball head 21 mate with each other. Figure 6 As shown, the reverse hip joint prosthesis provided by the present invention can be securely connected to the human acetabulum through the bone body fitting part 22, the femoral cup 11 and the acetabular ball head 21 can cooperate with each other, while the femoral stem 12 usually cooperates with the human femoral medullary cavity.

[0043] The reverse hip joint prosthesis provided by this invention may include a femoral side prosthesis 1, which is designed for installation into the femoral medullary cavity of the human body. The femoral side prosthesis 1 can be personalized using 3D printing technology, thereby achieving better fit with the femoral medullary cavity of different patients and ensuring appropriate angular fit between various components.

[0044] The aforementioned femoral prosthesis 1 may include a femoral stem 12. The femoral stem 12 is typically used to fit into the medullary canal of the femur, primarily serving to fix and support the femoral cup 11. The femoral stem 12 usually has a smooth outer surface and a suitable cross-sectional shape to ensure a proper fit between the femoral stem 12 and the medullary canal. For example, the femoral stem 12 may be a truncated cone with a certain taper, and its cross-section may be elliptical.

[0045] The aforementioned femoral prosthesis 1 may include a connecting neck 13. The connection angle between the connecting neck 13 and the femoral cup 11 and femoral stem 12, as well as its own length, largely depends on the position of the femoral cup 11 relative to the femoral stem 12. Generally, the connecting neck 13 typically has a smooth outer surface and a suitable cross-sectional shape to ensure that the angle of the femoral cup remains constant and does not change during movement. For example, the connecting neck 13 can be a cylinder or a frustum with a certain taper, and its cross-section can be elliptical, etc.

[0046] The aforementioned femoral prosthesis 1 may include a femoral cup 11. The femoral cup 11 is typically connected to a connecting neck 13, forming a single unit. Compared to traditional hip replacement, this is a reverse-mounted prosthesis cup, connected to the femoral stem 12 via the connecting neck 13. The orientation of the femoral cup 11 corresponds to the orientation of the acetabular head 21 and needs to meet the limitation of non-dislocation within the normal range of rotational angles during human activity. Generally, the anteversion angle of the femoral cup 11 needs to match the anteversion angle of the femur to improve hip joint stability and prevent misalignment between the acetabular head 21 and the femoral cup 11 when the subject is subjected to external forces (e.g., impacts during exercise). For example, the neck-shaft angle between the connecting neck 13 and the femoral stem 12 can be 125–140°, 125–130°, 130–135°, or 135–140°. For example, the perpendicular distance from the center of the acetabular head 21 to the axis of the femoral stem 12 can be 30–40 mm, 30–32 mm, 32–34 mm, 34–36 mm, 36–38 mm, or 38–40 mm. For example, the center of the femoral cup 11 is usually located on the extension line connecting the neck 13. For example, when a reverse hip joint prosthesis is fitted to the corresponding human body part, under the following conditions: flexion of 110-120° (the angle formed by the thigh and the vertical axis when the affected thigh is bent close to the chest in the sagittal plane in a normal supine position), abduction of 45° to adduction of 15° (the angle formed by the affected thigh and the vertical axis when it rotates laterally and medially in the coronal plane in a normal supine position), hip flexion of 90° with internal rotation of 30° to external rotation of 30° (the angle formed by the affected lower leg and the vertical axis when it rotates laterally and medially in the coronal plane in a normal sitting position), and hip extension with external rotation to 90° (the angle formed by the sagittal axis when it rotates laterally in the horizontal plane in a normal prone position), the projection of the center of the acetabular head 21 onto the vertical axis (of the human body) does not fall outside the femoral cup 11.

[0047] In the aforementioned femoral prosthesis 1, a spacer 14 may also be provided in the femoral cup 11. The spacer 14 is mainly used for buffering between the acetabular ball head 21 and the cup body of the femoral cup 11 to improve the fit between the two. The spacer 14 is usually made of high molecular weight polyethylene, ceramic, etc.

[0048] In the aforementioned femoral prosthesis 1, the various components of the femoral prosthesis 1 can be assembled in a suitable manner to facilitate preparation and carrying. For example, the femoral cup 11 and the connecting neck 13 can be connected by interference fit or sleeve, or by press fit, to achieve locking of freedom in all directions.

[0049] The reverse hip joint prosthesis provided by this invention may include an acetabular-side prosthesis 2, which is designed for use with severe acetabular defects. The acetabular-side prosthesis 2 can be customized using 3D printing technology, thereby enabling better fit with the defective acetabulum of different patients and meeting the requirements for angular fit with the femoral cup 11.

[0050] The aforementioned acetabular prosthesis 2 may include an acetabular ball head 21. The acetabular ball head 21 is typically a suitable spherical shape that matches the femoral cup 11. In this invention, the installation position of the acetabular ball head 21 is opposite to that of a conventional ball head, primarily achieving a reverse fit between the acetabular ball head 21 and the femoral cup 11.

[0051] The aforementioned acetabular prosthesis 2 may include a bone-fitting portion 22. This portion primarily serves as the base of the acetabular prosthesis 2, providing a forceful connection with a severely damaged acetabulum. The fitting surface of the bone-fitting portion 22 is typically rough, and its shape is usually adapted to the acetabulum to ensure a tight fit. The bone-fitting portion 22 is typically used to fit the best bone tissue of the subject for a forceful connection. For example, at least a portion of the bone-fitting portion 22 may be used to fit areas of dense bone, specifically fitting one or more of the following combinations: the acetabular body in the ischial ramus direction, the acetabular body in the pubic ramus direction, or the acetabular body in the iliac direction. Generally, the bone-fitting portion 22 may have suitable structures to facilitate its connection with the acetabulum. For example, the bone-fitting portion 22 may have a through hole, and the acetabular prosthesis 2 may also include a pelvic fixation member 24 (e.g., a fixing screw), which typically mates with the through hole to connect the bone-fitting portion 22 to the acetabulum. As another example, the bone-fitting portion 22 may also include a fitting extension portion 221, which further increases the fitting area between the bone-fitting portion 22 and the acetabulum to reinforce the connection. The fitting extension portion 221 may form an integral part with the bone-fitting portion 22.

[0052] The aforementioned acetabular prosthesis 2 may include a ball-head support 23. The ball-head support 23 is mainly used to connect the force-bearing positions in the acetabular prosthesis 2 (e.g., the acetabular ball head 21 and the bone-body fitting portion 22) to form suitable support. For example, the ball-head support 23 may include a central portion 231, which may be the junction of the connection between the acetabular ball head 21 and each bone-body fitting portion 22. The bone-body fitting portion 22 may be connected to the central portion 231, thereby providing a suitable force-bearing position for the ball-head support 23. The acetabular ball head 21 may be connected to the central portion 231 for cooperation with the acetabular ball head 21, and the overall relative position of the ball-head support 23 may be adjusted according to the angular relationship between the connection between the acetabular ball head 21 and the central portion 231 and the femoral cup 11. Each part of the ball head support 23 typically has a smooth outer surface. For example, the central part 231 can be spherical, and the connection between the acetabular ball head 21 and / or the bone body fitting part 22 and the central part 231 can be a column or a truncated platform with a certain taper, etc., and its cross-section can be circular or elliptical, etc.

[0053] In the aforementioned acetabular prosthesis 2, the various components of the acetabular prosthesis 2 can be assembled in a suitable manner to facilitate preparation and carrying. For example, the acetabular ball head 21 and the ball head support 23 can be connected by interference fit or sleeve, etc., to achieve locking of the degrees of freedom in all directions.

[0054] For patients with severe acetabular defects undergoing total hip replacement or revision surgery, the bone retention in the acetabulum is often insufficient to meet the requirements for placing the acetabular cup prosthesis. The acetabulum's suitability for cup placement is poor, making it difficult to achieve the desired surgical outcome. The reverse hip joint prosthesis provided by this invention helps patients achieve optimal surgical results. Furthermore, the femoral cup orientation in this reverse hip joint prosthesis is determined by ensuring the acetabular head does not dislodge in a normal hip joint posture. Therefore, the femoral cup orientation is unique, allowing for mass production of the femoral cup and stem using traditional metalworking processes, resulting in standard parts of various sizes for selection. In the acetabular side prosthesis, the acetabular head typically corresponds to the femoral cup, while the remaining parts can be custom-made for each patient. This ensures both a unique acetabular head orientation and a secure connection between the acetabular side prosthesis and the appropriate location on the patient's acetabulum. Overall, the reverse hip joint prosthesis provided by this invention can avoid various problems when reconstructing a stable acetabular cup on the pelvic side in cases of severe acetabular defects, obtain acetabular cup and ball head sizes that are more suitable for patients, and overcome the limitations of reverse hip in angles such as anteversion and abduction, with relatively greater freedom. It can effectively reduce surgical difficulty and cost, improve surgical structure, and has good industrialization prospects.

[0055] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0056] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A reverse hip joint prosthesis, characterized in that, The device includes a femoral prosthesis (1) and an acetabular prosthesis (2). The femoral prosthesis (1) includes a femoral cup (11) and a femoral stem (12), which are connected by a connecting neck (13). The acetabular prosthesis (2) includes an acetabular ball head (21) and a bone-body fitting portion (22), which are connected by a ball head support (23). The femoral cup (11) and the acetabular ball head... (21) In conjunction with the bone body fitting portion (22), the bone body fitting portion (22) serves as the base of the acetabular side prosthesis (2) and is used to forcefully fit and connect with the severely defective acetabulum; the acetabular side prosthesis (2) includes multiple bone body fitting portions (22), at least a portion of which is used to fit one or more of the acetabular bone body in the direction of the ischial ramus, the acetabular bone body in the direction of the pubic ramus, or the acetabular bone body in the direction of the ilium; the bone body fitting portion (22) also includes a fitting extension portion (221).

2. The reverse hip joint prosthesis as described in claim 1, characterized in that, The bonding surface of the bone body fitting part (22) is a rough surface.

3. The reverse hip joint prosthesis as described in claim 1, characterized in that, The bone-fitting part (22) is provided with a through hole.

4. The reverse hip joint prosthesis as described in claim 3, characterized in that, The acetabular prosthesis (2) also includes a pelvic fixation member (24) which cooperates with the through hole.

5. The reverse hip joint prosthesis as described in claim 1, characterized in that, The ball head support (23) includes a central part (231), and the acetabular ball head (21) and each bone body fitting part (22) are respectively connected to the central part (231).

6. The reverse hip joint prosthesis as described in claim 5, characterized in that, The neck-shaft angle between the connecting neck (13) and the femoral stem (12) is 125-140°, the perpendicular distance from the center of the acetabular ball head (21) to the axis of the femoral stem (12) is 30-40 mm, and the center of the femoral cup (11) is located on the extension line of the connecting neck (13).

7. The reverse hip joint prosthesis as described in claim 1, characterized in that, The femoral cup (11) is also provided with a gasket (14).

8. The reverse hip joint prosthesis as described in claim 1, characterized in that, When the reverse hip joint prosthesis is matched to the corresponding human body part, the projection of the center of the acetabular head (21) on the vertical axis does not fall outside the femoral cup (11) when the hip is flexed at 110-120°, when the hip is abducted at 45° to adducted at 15°, when the hip is flexed at 90° and the thigh is internally rotated at 30° to externally rotated at 30°, and when the hip is extended and externally rotated at 90°.

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