Acetabular cup-acetabular cushion block system for 3D printing of tantalum coating

Abstract

The invention discloses a tantalum coating 3D printing acetabular cup-acetabular cushion block system, and belongs to the technical field of medical prostheses. The acetabular cushion block and the acetabular cup are firmly combined with the hip bone through screws, and the porous tantalum coating promotes bone ingrowth and achieves a better biological fixation effect. The radian of the acetabular cushion block is customized according to the bone defect position of a patient, the combination position of the acetabular cushion block and the acetabular cup can be selected, the angle can be flexibly adjusted, the acetabular cushion block is combined with the acetabular cup through a bottom adjustable lock catch, a self-locking structure is arranged, and uneven stress of the acetabular cup caused by looseness is prevented.

Description

Technical Field

[0001] This invention relates to the field of medical prosthesis technology, and in particular to a tantalum-coated 3D-printed acetabular cup-acetabular pad system. Background Technology

[0002] Total hip arthroplasty has been developed for several years and is now widely used and proven to effectively restore hip joint function. With the increasing number of hip surgeries and the growing number of years since prostheses were implanted, the number of revision surgeries has also increased. Common reasons for requiring hip revision surgery include prosthesis wear, mechanical loosening, hip instability, and infection, with many cases involving acetabular defects. To address this challenge, the combined use of acetabular cup and acetabular cup pad design for fixation is a rapidly developing field, providing a practical and effective solution for prosthesis fixation and acetabular bone defect reconstruction.

[0003] 3D-printed titanium bone implants have been widely developed in the field of orthopedic implants due to their excellent biocompatibility and mechanical properties. They possess characteristics similar to cortical bone, such as low elastic modulus, low density, high corrosion resistance, and good biocompatibility, and have therefore been developed into medical devices such as knee / hip joint prostheses, spinal implants, and bone plates and screws. The trabecular bone structures fabricated using 3D printing technology have a diameter of approximately 150 μm, close to the 100–140 μm size of natural trabecular bone. Simultaneously, the rough scaffold structure promotes osteoblast adhesion and proliferation, achieving bio-fixation between the implant and bone tissue. During the 3D printing process, the density, strength, and elastic modulus of the prosthesis can be adjusted by modifying the pore size and porosity, achieving a dual adaptation of the prosthesis's external surface morphology and mechanical properties to the patient's own bone.

[0004] 1. The shape of the existing pad cannot fit the shape of the acetabulum, and there are gaps on the contact surface with the acetabulum, which can easily lead to loosening. The position and shape of the acetabular pad cannot be freely adjusted. Cases of acetabular defects are complex and cannot be widely applied to acetabular repair in multiple cases.

[0005] 2. The acetabular cup has a chamfer on only the outer surface of the porous layer, which makes it impossible to connect with other auxiliary prostheses such as pads. In cases of severe acetabular defects, the bone contact area is small, which cannot achieve a good biological fixation and osseointegration effect. Summary of the Invention

[0006] In view of this, the present invention proposes a tantalum-coated 3D-printed acetabular cup-acetabular pad system. The acetabular pad and the acetabular cup are firmly attached to the hip bone by screws. The porous tantalum coating promotes bone ingrowth and provides better biological fixation. The curvature of the acetabular pad is customized according to the location of the patient's bone defect and the engagement position with the acetabular cup can be selected, allowing for flexible angle adjustment. It engages with the acetabular cup via an adjustable locking buckle at the bottom and has a self-locking structure to prevent loosening that could lead to uneven stress on the acetabular cup.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A tantalum-coated 3D-printed acetabular cup-acetabular pad system includes an acetabular cup and an acetabular pad.

[0009] The acetabular cup has a multi-layered hemispherical structure, including an acetabular cup liner, an intermediate layer, and a tantalum coating layered sequentially from the inside to the outside; the acetabular cup liner has an annular rim, and the two are coaxial and integral; the intermediate layer and the tantalum coating are both connected to the annular rim;

[0010] The inner side of the annular edge is provided with a locking base; the outer side of the locking base and the inner side of the annular edge are respectively provided with a wave-shaped protrusion and a wave-shaped groove;

[0011] One end of the acetabular pad is provided with a wave-shaped buckle; the wave-shaped buckle is embedded between the annular edge and the locking base; the wave-shaped protrusion is adapted to one side of the wave-shaped buckle, and the wave-shaped groove is adapted to the other side of the wave-shaped buckle.

[0012] Furthermore, the intermediate layer is a titanium alloy trabecular structure with a thickness of 0.5-3 mm and a porosity of 50%-80%; the tantalum coating has a thickness of 5-30 μm and a porosity of 60-80%.

[0013] Furthermore, both the acetabular cup and the acetabular pad are connected to the human hip bone by screws; both the acetabular cup and the acetabular pad are provided with fixing screw holes and auxiliary mounting screw holes;

[0014] Furthermore, the acetabular cup liner is made of ultra-high molecular weight polyethylene, which is tightly bonded to the titanium alloy trabecular bone layer using a hot-pressing method.

[0015] Furthermore, the annular rim coincides with the circular edge of the acetabular cup liner.

[0016] Furthermore, the locking base is a split structure; the central angle of the arc of each part is less than 180°.

[0017] Furthermore, both ends of the locking base are locked to the inner side of the annular edge by bolt assemblies.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. This technology combines a porous tantalum coating with 3D-printed titanium bone implants, integrating the advantages of both. 3D-printed all-tantalum implants suffer from high production costs and significant impacts on mechanical properties due to the molding process; while porous titanium has mature processing technology. Applying a porous tantalum coating (5-30μm) to the surface of titanium alloy trabecular bone via vapor deposition is more conducive to osteoblast ingrowth and attachment; this reduces production costs and improves the osseointegration performance of the prosthesis. After initial good biointegration, osteoblasts can continue to grow into the titanium alloy trabecular bone layer, achieving a more stable integration effect.

[0020] 2. This technology features an adjustable locking structure where the annular rim and acetabular cup liner are integrally manufactured. The snap-fit ​​at the lower end of the acetabular pad matches the fixing groove structure, and the rough inner surface prevents the pad from dislodging. Bolt assemblies are used to apply pressure to ensure a secure connection between the annular rim and the locking base. This acetabular cup-acetabular pad system allows for flexible selection of the pad insertion position and number to meet the needs of patients with different hip bone defects. Furthermore, when adjustments are required, the entire structure can be freely reassembled by disassembling the locking base and screws, eliminating the need for repeated manufacturing. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the outer surface of the acetabular cup in an embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional view of the acetabular cup in an embodiment of the present invention.

[0023] Figure 3 This is a front structural diagram of the acetabular pad in an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the side structure of the acetabular pad in an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the assembly of the acetabular pad and acetabular cup in an embodiment of the present invention.

[0026] Figure 6 This is a partial schematic diagram of the structure of the acetabular cup bottom ring and the locking base after assembly in an embodiment of the present invention.

[0027] In the diagram: 1. Fixed pin hole a, 2. Auxiliary pin mounting pin hole a, 3. Tantalum coating, 4. Intermediate layer, 5. Acetabular cup liner, 7. Fixed pin hole b, 8. Auxiliary pin mounting pin hole b, 9. Clip, 6. Fixing groove, 10. Locking bolt. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be fully described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] This embodiment includes an acetabular cup and an acetabular pad. The acetabular pad and the acetabular cup are firmly attached to the hip bone by screws. The porous tantalum coating promotes bone ingrowth and provides better biological fixation. The curvature of the acetabular pad is customized according to the location of the patient's bone defect and the position of engagement with the acetabular cup can be selected. The angle can be flexibly adjusted. It is engaged with the acetabular cup through an adjustable buckle at the bottom and has a self-locking structure to prevent loosening that could lead to uneven force on the acetabular cup.

[0030] The acetabular cup has a multi-layered hemispherical structure, including an acetabular cup liner, an intermediate layer, and a tantalum coating layered sequentially from the inside out; the acetabular cup liner has an annular rim, and the two are coaxial and integral; the intermediate layer and the tantalum coating are both connected to the annular rim; for details, refer to [reference needed]. Figures 1 to 2 The main body consists of three parts. The outermost layer is a tantalum coating prepared by chemical vapor deposition, with a thickness of 5-30 μm and a porosity of 60-80%. The middle layer is a titanium alloy trabecular bone structure with a thickness of 0.5-3 mm and a porosity of 50%-80%, which can be adjusted according to the patient's needs. The inner layer is the acetabular cup liner, which is made of ultra-high molecular weight polyethylene and is tightly bonded to the titanium alloy trabecular bone layer by hot pressing.

[0031] An example of an acetabular pad is shown below. Figure 3 and Figure 4 As shown, the material is similar to the acetabular cup structure, featuring a double-layer design. The outer layer also uses chemical vapor deposition to prepare a porous tantalum coating, while the inner layer is a 3D-printed titanium alloy trabecular structure with thickness and shape customized according to patient needs. Toothed snaps are printed on the bottom side of the acetabular pad to engage with the acetabular cup's fixing groove (formed by the annular rim and locking base) for a secure fit.

[0032] The inner side of the annular edge is provided with a locking base; the outer side of the locking base and the inner side of the annular edge are respectively provided with a wavy protrusion and a wavy groove; see details below. Figure 6In this embodiment, a space is provided between the wavy protrusion and the wavy groove for the insertion of the snap fastener; the fixing groove consists of an inner locking base and an outer annular edge. The outer annular edge is integrally machined with the acetabular cup liner, and the inner locking base is movable. The fixing groove formed by the two is slightly smaller than the toothed snap fastener. After being locked with screws, it forms a locking structure with the metal snap fastener. The tantalum metal contact surface of the toothed (wavy) snap fastener is rough, increasing the friction of the contact surface and preventing the toothed snap fastener from dislodging. If the position of the assembled pad needs to be adjusted, the fixing screws can be removed and the inner and outer fixing blocks separated and reassembled to meet the needs of different types of patients.

[0033] One end of the acetabular pad is provided with a wave-shaped buckle; the wave-shaped buckle is embedded between the annular edge and the locking base; the wave-shaped protrusion is adapted to one side of the wave-shaped buckle, and the wave-shaped groove is adapted to the other side of the wave-shaped buckle.

Claims

1. A tantalum-coated 3D-printed acetabular cup-acetabular pad system, characterized in that, Includes acetabular cup and acetabular pad, The acetabular cup has a multi-layered hemispherical structure, including an acetabular cup liner, an intermediate layer, and a tantalum coating layered sequentially from the inside to the outside; the acetabular cup liner has an annular rim, and the two are coaxial and integral; the intermediate layer and the tantalum coating are both connected to the annular rim; The inner side of the annular edge is provided with a locking base; the outer side of the locking base and the inner side of the annular edge are respectively provided with a wave-shaped protrusion and a wave-shaped groove; One end of the acetabular pad is provided with a wave-shaped buckle; the wave-shaped buckle is embedded between the annular edge and the locking base; the wave-shaped protrusion is adapted to one side of the wave-shaped buckle, and the wave-shaped groove is adapted to the other side of the wave-shaped buckle.

2. The tantalum-coated 3D-printed acetabular cup-acetabular pad system according to claim 1, characterized in that, The intermediate layer is a titanium alloy trabecular structure with a thickness of 0.5-3 mm and a porosity of 50%-80%; the tantalum coating has a thickness of 5-30 μm and a porosity of 60-80%.

3. The tantalum-coated 3D-printed acetabular cup-acetabular pad system according to claim 1, characterized in that, Both the acetabular cup and the acetabular pad are attached to the human hip bone by screws; both the acetabular cup and the acetabular pad are provided with fixing screw holes and auxiliary installation screw holes.

4. The tantalum-coated 3D-printed acetabular cup-acetabular pad system according to claim 2, characterized in that, The acetabular cup liner is made of ultra-high molecular weight polyethylene, which is tightly bonded to the titanium alloy trabecular bone layer by hot pressing.

5. The tantalum-coated 3D-printed acetabular cup-acetabular pad system according to claim 1, characterized in that, The annular rim coincides with the circular edge of the acetabular cup liner.

6. The tantalum-coated 3D-printed acetabular cup-acetabular pad system according to claim 1, characterized in that, The locking base is a split structure; the central angle of the arc of each part is less than 180°.

7. The tantalum-coated 3D-printed acetabular cup-acetabular pad system according to claim 6, characterized in that, Both ends of the locking base are locked to the inner side of the annular edge by bolt assemblies.

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