Nested assembly internal fixation device for intra-articular distal radius fractures

Abstract

The present invention discloses a nested assembly type internal fixation device for distal radial intra-articular fractures, the internal fixation device comprises a titanium alloy steel plate designed based on the palmar anatomical morphology of the distal radius, a distal absorbable module and an absorbable support rod, the distal lower edge of the titanium alloy steel plate can be closely attached to the watershed edge of the distal radius, a fracture window top pressure reduction area corresponding to the collapsed area of ​​the distal radial articular surface is provided on the titanium alloy steel plate, a steel plate distal locking hole is provided on the distal side of the fracture window top pressure reduction area, and a steel plate proximal locking groove is provided on the proximal side, at least one absorbable support rod is implanted in the collapsed area of ​​the distal radial articular surface and the front end of the absorbable support rod is located in the severe collapsed area, a distal absorbable module is fixedly installed in the fracture window top pressure reduction area, and the bottom of the distal absorbable module is in close contact with the upper edge of the tail of the absorbable support rod. The internal fixation device of the present invention can be ultra-distal fixed, convenient for window top pressure reduction of the articular surface and can effectively maintain fixation.

Description

Technical Field

[0001] The invention belongs to the technical field of orthopedic medical instruments, in particular to a nested assembly type internal fixation device for intra-articular fractures of distal radius. Background Art

[0002] Distal radius fracture is a common fracture type, among which the fracture type with fracture line close to the articular surface and comminuted and collapsed articular surface is particularly complex. Traditional treatment methods often have problems of weak fixation and easy displacement, resulting in slow or poor fracture healing, affecting the patient's rehabilitation and quality of life. With the continuous development of materials science and biomedical engineering, more and more new biomaterials and internal fixation devices are used in fracture treatment; at the same time, with the continuous updating of fracture treatment concepts, more emphasis is placed on individualized treatment and optimization of the mechanical environment. Among them, absorbable materials, as a material with good biocompatibility and in vivo degradation, have gradually attracted attention. They can be degraded in the body and gradually replaced by human tissue, thus avoiding the need for secondary surgery. Polylactic acid, as a degradable material, has good biocompatibility and degradability and is widely used in the field of medical devices; the application of polylactic acid materials in fracture internal fixation devices can have a good supporting role in the early stage of fracture healing process, and then gradually degrade and fuse with surrounding bones to reduce local tissue irritation. Biological fixation technology emphasizes the biological environment of fracture treatment, reduces mechanical interference to the fracture site, and promotes the natural healing process of the fracture; therefore, biological fixation technology has developed rapidly as one of the important means of fracture treatment.

[0003] At present, due to the limitations of existing traditional fixation methods and existing materials, the technologies and fixation products for treating distal radial intra-articular fractures have the following objective disadvantages:

[0004] 1. Insecure fixation: For distal radius fractures, especially those with fracture lines close to the articular surface and comminuted and collapsed articular surface, due to the special anatomical structure and complex biomechanical environment of the fracture site, traditional methods such as plaster fixation and splint fixation are difficult to provide stable and reliable fixation, which can easily lead to fracture displacement and poor healing;

[0005] 2. Insufficient material strength: Since the strength of polylactic acid steel plates made of polylactic acid materials is limited, polylactic acid steel plates are currently only suitable for non-weight-bearing areas; at the same time, polylactic acid steel plates are regular in shape, while the area around the radiocarpal joint is complex and irregular in shape, making it impossible to use polylactic acid steel plates;

[0006] 3. Limitations of metal materials: Traditional materials will produce stress shielding effect in the body, affecting the healing of fracture sites; in addition, metal materials also have risks such as allergies and infections, posing a potential threat to patients' health; and during the fracture healing process, the stiffness of the internal fixation device changes, and the constant mechanical properties of metal materials may cause bending, fracture, etc., resulting in fixation failure;

[0007] 4. Second surgery is required: Metal materials are not easily degraded in the body, and metal internal fixation devices need to be removed by a second surgery after the fracture heals, which brings certain pain and financial burden to the patient;

[0008] 5. Mechanical environment that is not conducive to fracture healing: Traditional internal fixation devices often cannot provide a good mechanical environment for the fracture site, affecting fracture healing; for example, rigid metal internal fixation devices will produce a stress shielding effect when bearing loads, making it difficult for the fracture site to heal.

[0009] Therefore, it is particularly important to develop an internal fixation device that comprehensively utilizes the advantages of existing materials for distal radius fractures, especially those in which the fracture line is close to the articular surface and the articular surface is comminuted and collapsed. Summary of the invention

[0010] The purpose of the present invention is to provide a nested assembly internal fixation device for distal radial intra-articular fractures, which has ultra-distal fixation, is convenient for opening windows and pressing the joint surface to reduce the joint surface, and can effectively maintain fixation, in order to solve the problems existing in the prior art.

[0011] The purpose of the present invention is to be solved by the following technical solutions:

[0012] A nested assembly type internal fixation device for intra-articular fracture of distal radius, characterized in that: the internal fixation device comprises a titanium alloy steel plate designed based on the palmar anatomical morphology of the distal radius, a distal absorbable module and an absorbable support rod, the distal lower edge of the titanium alloy steel plate can be tightly attached to the watershed edge of the distal radius, a fracture window top pressure reduction area corresponding to the collapsed area of ​​the distal articular surface of the radius is provided on the titanium alloy steel plate, a steel plate distal locking hole is provided on the distal side of the fracture window top pressure reduction area, and a steel plate proximal locking groove is provided on the proximal side, at least one absorbable support rod is implanted in the collapsed area of ​​the distal articular surface of the radius and the front end of the absorbable support rod is located in the severe collapsed area of ​​the collapsed area of ​​the distal articular surface of the radius, a distal absorbable module is fixedly installed in the fracture window top pressure reduction area, and the bottom of the distal absorbable module is in close contact with the upper edge of the tail of the absorbable support rod.

[0013] The upper edge of the tail of the absorbable support rod is located at 1 / 3 of the distance from the proximal end to the distal end of the distal absorbable module.

[0014] The implantation angle of the absorbable support rod is 45° to 75° to achieve the best top pressure reduction effect; the absorbable support rod as the osteogenic induction component adopts a hexagonal cross-sectional structure.

[0015] A distal module locking hole is provided on the proximal side of the distal absorbable module, and the distal module locking hole is used to implant a titanium alloy locking screw with a titanium alloy spring ring to appropriately apply pressure and maintain close contact between the absorbable support rod and the distal absorbable module; distal Kirschner wire holes are provided on both sides of the distal module locking hole, and the distal Kirschner wire holes are used to temporarily lock the distal absorbable module in the fracture window top pressure reduction area.

[0016] The distal outer edge of the distal absorbable module is provided with a distal module absorbable groove, and a steel plate distal absorption groove is provided on the titanium alloy steel plate on the distal side of the fracture window top pressure reduction area. The relatively arranged distal module absorbable groove and the steel plate distal absorption groove constitute a distal absorbable hole, and the distal absorbable hole is used to implant an absorbable screw with an absorbable polylactic acid ring or a titanium alloy screw with an absorbable polylactic acid ring.

[0017] The width of the distal absorbable module is 12 mm to 22 mm, and the edge width of the titanium alloy steel plates on both sides of the distal absorbable module is 3 mm to 4 mm.

[0018] The distal locking hole and the proximal locking groove of the steel plate can be respectively implanted with titanium alloy screws to fix the titanium alloy steel plate; the proximal locking groove of the steel plate is a U-shaped groove structure, so that the titanium alloy screw at the proximal locking groove of the steel plate can adjust its position.

[0019] A plurality of proximal articular surface Kirschner wire holes are arranged on the distal outer edge of the titanium alloy steel plate. The proximal articular surface Kirschner wire holes opening outward are used for implanting proximal articular surface Kirschner wires. The proximal articular surface Kirschner wires are used to temporarily position the titanium alloy steel plate and guide the titanium alloy screws implanted at the distal locking holes of the steel plate; a spare Kirschner wire hole is provided on the titanium alloy steel plate on the proximal side of the distal locking holes of the steel plate, a spare Kirschner wire hole is provided on the titanium alloy steel plate between the fracture window top pressure reduction area and the proximal locking groove of the steel plate, and a spare Kirschner wire hole is provided on the proximal tail of the titanium alloy steel plate.

[0020] The proximal side of the proximal locking groove of the steel plate is provided with a strip-shaped proximal locking area of ​​the steel plate, and the distal side of the proximal locking area of ​​the steel plate is connected with the proximal locking groove of the steel plate; the proximal locking area of ​​the steel plate is used to embed a proximal absorbable module with a proximal module locking hole, and the proximal module locking hole opening at the distal end of the proximal absorbable module is connected to the proximal locking groove of the steel plate, and titanium alloy screws and / or absorbable screws are implanted in the proximal module locking hole to position and fix the proximal absorbable module in the proximal locking area of ​​the steel plate.

[0021] The edge width of the titanium alloy steel plate on both sides of the distal end of the proximal locking zone of the steel plate is 1mm to 2mm, and the edge width of the titanium alloy steel plate on both sides of the proximal end is less than 1mm, so that the proximal locking zone of the steel plate presents a strip-shaped groove that gradually expands from the distal end to the proximal end of the titanium alloy steel plate.

[0022] The distal absorbable module, the proximal absorbable module, the absorbable polylactic acid ring, the absorbable screw and the absorbable support rod are all made of polylactic acid absorbable material.

[0023] In the above scheme, the distal end of the radius is near the wrist joint, and one end of the titanium alloy steel plate near the wrist joint is defined as the distal end of the titanium alloy steel plate, and the other end of the titanium alloy steel plate is defined as the proximal end of the titanium alloy steel plate. All "distal sides" involved in the technical scheme refer to the side relatively close to the wrist joint, and "proximal sides" refer to the side relatively far away from the wrist joint.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The nested assembly type internal fixation device provided by the present invention has a design of ultra-distal fixation and convenient window opening, top pressure reduction of the joint surface and effective maintenance of fixation. By compounding the absorbable parts made of polylactic acid material on the titanium alloy steel plate, the use of metal materials is reduced. At the same time, the absorbable support rod as the osteogenic induction component helps the rapid healing of the fracture site. Thus, the problems of weak fixation and easy displacement existing in traditional treatment methods are solved, and the device has broad application prospects and important social significance.

[0026] The nested assembly internal fixation device provided by the present invention adopts an anatomical design, which can better adapt to the anatomical morphology of the palmar side of the distal radius, improve the stability of fixation and the treatment effect; use Kirschner wires near the articular surface for 3 / 4 hole fixation, and perform positioning and guiding subchondral titanium alloy screw fixation to ensure the stability of the device; the positioning and guiding subchondral titanium alloy screws can accurately fix the fracture collapse area and improve the treatment effect; the fracture window opening and top pressure reduction area is convenient for window opening and top pressure reduction of the articular surface and can effectively maintain the special design of fixation, avoids damage to the radiocarpal joint, and reduces the occurrence of postoperative complications; at the same time, the structure made of a composite of titanium alloy material and polylactic acid material can gradually degrade during the fracture healing process, reducing the burden on patients.

[0027] The nested assembly type internal fixation device provided by the present invention provides more support through multiple rows of screws, thereby achieving fixation of the distal end of the radius and improving the stability and reliability of fixation.

[0028] The osteogenic induction component used in the nested assembly internal fixation device provided by the present invention is conducive to the rapid healing of the fracture site. The polylactic acid absorbable material can grow with the callus in a permeable manner and fuse tightly, which can avoid the re-collapse after the internal fixation is removed and improve the stability of the treatment; the absorbable material reduces the need for secondary surgery and alleviates the pain and economic burden of the patient.

[0029] The nested assembly type internal fixation device provided by the present invention is composed of a composite of polylactic acid absorbable material and titanium alloy, and has a micro-motion connection and a nested assembly structure design. It can adjust the fixation strength and micro-motion according to the different stages of fracture healing to promote fracture healing and reduce the stress shielding effect; the polylactic acid absorbable material can reduce the stress shielding of the titanium alloy steel plate, which is mainly distributed in the low-stress area of ​​the device. Due to the presence of the nested micro-motion structure, it can promote fracture healing. With the complete absorption of the polylactic acid absorbable material, the internal fixation device can be regarded as an internal fixation bracket structure to further reduce complications. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Attached Figure 1 A schematic diagram of the main structure of the nested assembly type internal fixation device for intra-articular fracture of distal radius provided by the present invention;

[0031] Attached Figure 2 A schematic diagram of the combined structure of the titanium alloy steel plate and the titanium alloy spring ring provided by the present invention;

[0032] Attached Figure 3 A schematic diagram of the structure of the distal absorbable module provided by the present invention;

[0033] Attached Figure 4 A schematic diagram of the structure of the proximal absorbable module provided by the present invention;

[0034] Attached Figure 5 A schematic diagram of the structure of the absorbable support rod provided by the present invention;

[0035] Attached Figure 6 A schematic diagram of the combined structure of the titanium alloy steel plate, the distal absorbable module, the proximal absorbable module, and the implanted absorbable support rod provided by the present invention;

[0036] Attached Figure 7 A schematic diagram of the structure of the absorbable polylactic acid ring provided by the present invention;

[0037] Attached Figure 8 A schematic diagram of the structure of a titanium alloy spring ring provided by the present invention;

[0038] Attached Fig. 9 The present invention provides Figure 1 Schematic diagram of the structure mounted on the radius;

[0039] Attached Fig.10The present invention is a perspective view of the use state of the nested assembly type internal fixation device for intra-articular fracture of distal radius provided by the present invention.

[0040] Among them: 1—titanium alloy steel plate; 11—Kirschner wire hole at the proximal joint surface; 12—distal locking hole of the steel plate; 13—distal absorption groove of the steel plate; 14—fracture window top pressure reduction area; 15—proximal locking groove of the steel plate; 16—proximal locking area of ​​the steel plate; 17—spare Kirschner wire hole; 2—distal absorbable module; 21—distal module absorbable groove; 22—distal module locking hole; 23—distal Kirschner wire hole; 24—distal absorbable hole; 3—proximal absorbable module; 31—proximal module locking hole; 4—titanium alloy screw; 5—titanium alloy spring ring; 6—absorbable polylactic acid ring; 7—absorbable screw; 8—titanium alloy locking screw; 9—absorbable support rod. DETAILED DESCRIPTION

[0041] In order to explain the technical content, structural features, objectives and effects of the invention in detail, the technical solutions in the embodiments of the present invention will be described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0042] In the present invention, spatial orientation terms such as "horizontal", "vertical", "front", "rear", "left", "right", "top", "on", "inside", "one side", etc. are used to describe the positional relationship, orientation or movement direction of components as shown in the accompanying drawings. This is only for the convenience of describing the present invention, and does not imply or indicate that the referred device or component must have a specific orientation or be constructed or operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium; "fixation" can be a full fixation in all directions, or it can be fixed in a certain direction so that the component cannot be offset or displaced in that direction, but can be moved in other directions.

[0044] like Figure 1-10As shown, the present invention provides a nested assembly type internal fixation device for distal radius intra-articular fracture, the nested assembly type internal fixation device comprises a titanium alloy steel plate 1 designed based on the palmar anatomical morphology of the distal radius, a distal absorbable module 2 and an absorbable support rod 9, wherein the distal lower edge of the titanium alloy steel plate 1 can be closely attached to the watershed edge of the distal radius, a fracture window top pressure reduction area 14 corresponding to the collapsed area of ​​the distal radius articular surface is provided on the titanium alloy steel plate 1, and a steel plate distal side is provided with a steel plate distal side. A distal locking hole 12 and a proximal locking groove 15 of the steel plate are provided on the proximal side. The distal locking hole 12 of the steel plate and the proximal locking groove 15 of the steel plate can be respectively implanted with titanium alloy screws 4 to fix the titanium alloy steel plate 1; at least one absorbable support rod 9 is implanted in the collapsed area of ​​the distal articular surface of the radius and the front end of the absorbable support rod 9 is located in the severe collapsed area of ​​the collapsed area of ​​the distal articular surface of the radius, and a distal absorbable module 2 is fixedly installed in the fracture window top pressure reduction area 14, and the bottom of the distal absorbable module 2 is in close contact with the upper edge of the tail of the absorbable support rod 9.

[0045] In the above structure, a plurality of proximal articular surface Kirschner wire holes 11 are arranged on the distal outer edge of the titanium alloy steel plate 1. The proximal articular surface Kirschner wire holes 11 opening outward are used for implanting proximal articular surface Kirschner wires. The proximal articular surface Kirschner wires are used to temporarily position the titanium alloy steel plate 1 and guide the titanium alloy screws 4 implanted at the distal locking holes 12 of the steel plate; a spare Kirschner wire hole 17 is provided on the titanium alloy steel plate 1 on the proximal side of the distal locking holes 12 of the steel plate, a spare Kirschner wire hole 17 is provided on the titanium alloy steel plate 1 between the fracture window top pressure reduction area 14 and the proximal locking groove 15 of the steel plate, and a spare Kirschner wire hole 17 is provided at the proximal tail of the titanium alloy steel plate 1. The spare Kirschner wire hole 17 is used only to position the titanium alloy steel plate 1 with a spare Kirschner wire when surgery requires it.

[0046] In the above structure, a distal module locking hole 22 is provided on the proximal side of the distal absorbable module 2, and the distal module locking hole 22 is used to implant a titanium alloy locking screw 8 with a titanium alloy spring ring 5 to appropriately apply pressure and maintain close contact between the absorbable support rod 9 and the distal absorbable module 2; distal Kirschner wire holes 23 are provided on both sides of the distal module locking hole 22, and the distal Kirschner wire holes 23 are used to temporarily lock the distal absorbable module 2 in the fracture window top pressure reduction area 14. A distal module absorbable groove 21 is provided at the distal outer edge of the distal absorbable module 2, and a steel plate distal absorption groove 13 is provided on the titanium alloy steel plate 1 on the distal side of the fracture window top pressure reduction area 14. The relatively arranged distal module absorbable groove 21 and the steel plate distal absorption groove 13 constitute a distal absorbable hole 24, and the distal absorbable hole 24 is used to implant an absorbable screw 7 with an absorbable polylactic acid ring 6 and / or a titanium alloy screw 4 with an absorbable polylactic acid ring 6, preferably an absorbable screw 7 with an absorbable polylactic acid ring 6. The fracture window top pressure reduction zone 14 where the distal absorbable module 2 is located is located in the central area in the width direction of the titanium alloy steel plate 1. The titanium alloy steel plate 1 on both sides of the fracture window top pressure reduction zone 14 needs to have a 3mm to 4mm titanium metal edge. The widest distal part of the distal absorbable module 2 does not exceed 22mm, and the narrowest proximal part is not less than 12mm, so that the fracture window top pressure reduction zone 14 is as large as possible, thereby expanding the volume of the distal absorbable module 2.

[0047] In the above structure, the proximal locking groove 15 of the steel plate is a U-shaped groove structure, so that the position of the titanium alloy screw 4 at the proximal locking groove 15 of the steel plate can be adjusted.

[0048] In the above structure, a strip-shaped proximal locking area 16 of the steel plate is provided on the proximal side of the proximal locking groove 15 of the steel plate, and the distal side of the proximal locking area 16 of the steel plate is connected with the proximal locking groove 15 of the steel plate; the proximal locking area 16 of the steel plate is used to embed the proximal absorbable module 3 with the proximal module locking hole 31, and the proximal module locking hole 31 at the distal end of the proximal absorbable module 3 is opened and connected with the proximal locking groove 15 of the steel plate, and a titanium alloy screw 4 and / or an absorbable screw 7 is implanted at the proximal module locking hole 31 to position and fix the proximal absorbable module 3 in the proximal locking area 16 of the steel plate. Since the proximal end of the nested assembly internal fixation device is a low stress area, the absorbable parts can be larger as they move toward the proximal end. Therefore, the edge width of the titanium alloy steel plate 1 on both sides of the distal end of the proximal locking zone 16 of the steel plate is 1mm to 2mm, and the edge width of the titanium alloy steel plate 1 on both sides of the proximal end is less than 1mm, so that the proximal locking zone 16 of the steel plate presents a strip-shaped groove that gradually expands from the distal end to the proximal end of the titanium alloy steel plate 1, which can maintain the overall integrity of the structure of the titanium alloy steel plate 1.

[0049] In the above structure, the absorbable support rod 9 made of polylactic acid material is a hexagonal prism structure. At this time, the upper edge of the tail of the absorbable support rod 9 implanted in the collapsed area of ​​the distal radial articular surface only needs at least one edge to be in close contact with the bottom of the distal absorbable module 2; the absorbable support rod 9 serves as an osteogenic induction component, and the window opening for implanting the absorbable support rod 9 is located at 1 / 3 of the distance from the proximal end to the distal end of the distal absorbable module 2, which can maximize the adjustment of the implantation angle of the absorbable support rod 9 (45°~75°) to achieve the best top pressure reduction effect.

[0050] The specific structure of a nested assembly type internal fixation device for distal radial intra-articular fracture provided by the present invention is demonstrated below through specific embodiments.

[0051] like Figure 1-29-10 are nested assembled internal fixation devices for distal radial intra-articular fractures, and are arranged in sequence from the distal end to the proximal end of the titanium alloy steel plate 1. There are four 3 / 4-hole proximal articular surface Kirschner wire holes 11 located at the distal outer edge, four distal locking holes 12 of the steel plate, three distal absorption grooves 13 of the steel plate, a fracture window top pressure reduction area 14, a proximal locking groove 15 of the steel plate, a proximal locking area 16 of the steel plate, and a plurality of spare Kirschner wire holes 17 located on the titanium alloy steel plate 1, and the proximal articular surface opening toward the outside. The Kirschner wire hole 11 is used to implant the proximal articular surface Kirschner wire to temporarily fix the titanium alloy steel plate 1, so that the nested assembly type internal fixation device can be as close to the articular surface as possible. The proximal articular surface Kirschner wire implanted in the proximal articular surface Kirschner wire hole 11 has a positioning and guiding function, which can better control the reduction and fixation of the fracture. It is a special design that is convenient for opening the window and pressing the articular surface to be reduced and can effectively maintain fixation; the distal locking hole 12 of the steel plate is used to implant the titanium alloy screw 4 that fixes the titanium alloy steel plate 1. A row of four titanium alloy screws 4 can provide more support, and can be used for early weight-bearing walking, and can also It can avoid the collapse again after the internal fixation is removed; the distal absorption groove 13 of the steel plate and the absorbable groove 21 of the distal module are combined to form a distal absorbable hole 24, and the distal absorbable hole 24 is used to implant an absorbable screw 7 with an absorbable polylactic acid ring 6, and the absorbable screw 7 with the absorbable polylactic acid ring 6 constitutes a micro-motion structure relative to the distal absorbable module 2 and the titanium alloy steel plate 1; the fracture window top pressure reduction area 14 is used to embed the distal absorbable module 2, and the distal absorbable module 2 is fixed with a titanium alloy locking screw 8 with a titanium alloy spring ring 5, and the titanium alloy The titanium alloy locking screw 8 of the spring ring 5 constitutes a micro-motion structure relative to the distal absorbable module 2; the proximal locking groove 15 of the steel plate is used to implant the titanium alloy screw 4 for fixing the titanium alloy steel plate 1, and the position of the titanium alloy screw 4 can be adjusted; the proximal locking area 16 of the steel plate is used to embed the proximal absorbable module 3, and the proximal absorbable module 3 is fixed with the absorbable screw 7 and / or the titanium alloy screw 4; the spare Kirschner wire hole 17 is used to temporarily implant the Kirschner wire to fix the titanium alloy steel plate 1, and the temporarily implanted Kirschner wire should be removed after the installation of the nested assembly internal fixation device is completed.

[0052] like Figure 3 , 9-10 shows a distal absorbable module 2, which is arranged in sequence from the distal end to the proximal end of the titanium alloy steel plate 1 with three open distal module absorbable grooves 21, a distal module locking hole 22 and two distal Kirschner wire holes 23. The distal module absorbable grooves 21 and the distal absorbable grooves 13 of the steel plate arranged relatively to each other constitute a distal absorbable hole 24 for implanting an absorbable screw 7 with an absorbable polylactic acid ring 6. The micro-motion structure formed by the absorbable screw 7 with the absorbable polylactic acid ring 6 can avoid the collapse again after the removal of the internal fixation in the secondary operation. At the same time, the absorbable polylactic acid ring 6 and the absorbable screw 7 have an osteogenic induction effect. The distal module locking hole 22 is used to implant a titanium alloy locking screw 8 with a titanium alloy spring ring 5 to appropriately pressurize and maintain close contact between the absorbable support rod 9 and the distal absorbable module 2. The distal Kirschner wire hole 23 is used to temporarily lock the distal absorbable module 2 in the fracture window top pressure reduction area 14.

[0053] like Figure 4 , 9 -10 shows a proximal absorbable module 3, on which four proximal module locking holes 31 are provided, wherein the opening of the proximal module locking hole 31 at the distal end of the proximal absorbable module 3 faces the proximal locking groove 15 of the steel plate.

[0054] like Figure 5-6 The absorbable support rod 9 shown in 9-10 is made of polylactic acid material and has a hexagonal prism structure. The absorbable support rod 9 is used to be implanted in the collapsed area of ​​the distal radial articular surface as an osteogenic induction component, and the front end of the absorbable support rod 9 is located in the severely collapsed area of ​​the collapsed area of ​​the distal radial articular surface. When the distal absorbable module 2 is used for positioning, only any side of the upper edge of the tail of the absorbable support rod 9 needs to be against the bottom surface of the distal absorbable module 2.

[0055] like Figure 7 , 9 -10 shows a partially open absorbable polylactic acid ring 6, which has threads inside. The distal absorbable hole 24 is formed by the distal absorbable groove 13 of the titanium alloy steel plate 1 and the distal module absorbable groove 21 of the distal absorbable module 2 to achieve micro-motion connection. The design of the micro-motion structure enables the fracture to have higher rigidity in the early stage of healing. As the fracture heals, the micro-motion of the fracture ends gradually disappears.

[0056] like Figure 8-10 The partially open titanium alloy spring ring 5 shown has a thread inside the ring, and together with the titanium alloy locking screw 8, forms a micro-motion structure relative to the distal absorbable module 2, thereby realizing the micro-motion connection of the distal absorbable module 2. The design of the micro-motion structure enables the micro-motion structure to have higher rigidity in the early stage of fracture healing. As the fracture heals, the micro-motion of the fracture end gradually disappears.

[0057] In the above structure, the micro-motion structure gradually generates micro-motion as the local absorbable material degrades, which can promote fracture healing in the later stage of fracture healing.

[0058] The following further explains the nested assembly internal fixation device for distal radial intra-articular fractures provided by the present invention from eight aspects, including special structure, material selection, avoiding locking nails from entering the radiocarpal joint, stress change and fracture healing, osteogenic induction, avoiding damage to the joint by metal materials, modular design, and universal locking function.

[0059] 1. Special structure: The nested assembly internal fixation device has an ultra-distal fixation design with a Kirschner wire hole 11 near the joint surface, which is convenient for opening a window and pressing the joint surface to be reset, and can effectively maintain fixation; this ultra-distal fixation design helps to accurately reduce and fix the fracture site.

[0060] 2. Material selection: The nested assembly internal fixation device is made of a composite of titanium alloy and polylactic acid absorbable material. Titanium alloy has good biocompatibility and strength, while polylactic acid absorbable material can be naturally degraded by the human body over time, thereby reducing the need for secondary surgery for the implant.

[0061] 3. Prevent locking nails from entering the radiocarpal joint: The nested assembly internal fixation device is designed to fit closely to the watershed edge of the distal end of the radius, which can effectively prevent the titanium alloy screw 4 implanted in the locking hole 12 at the distal end of the steel plate from being driven into the radiocarpal joint, thereby reducing further damage to the joint.

[0062] 4. Stress change and fracture healing: Due to the absorption of the polylactic acid absorbable material in different composite parts, the stress of the titanium alloy steel plate 1 will change during the fracture healing stage. The design of this composite structure is more in line with the mechanical environment of fracture healing.

[0063] 5. Osteogenesis induction: Adding some absorbable polylactic acid material to the bone defect has an osteogenic induction effect (the combination of absorbable polylactic acid ring 6 and absorbable screw 7, and hexagonal absorbable support rod 9), which helps the healing of the fracture site.

[0064] 6. Avoiding damage to joints caused by metal materials: By using absorbable components such as the distal absorbable module 2, the proximal absorbable module 3, the absorbable polylactic acid ring 6, the absorbable screw 7, the absorbable support rod 9, etc., further damage to the joints caused by metal materials can be effectively avoided.

[0065] 7. Modular design: The distal end of the titanium alloy steel plate 1 adopts a nested design of distal absorbable module 2, and the proximal end adopts a nested design of proximal absorbable module 3. This modular design makes the implant more flexible and also helps to reduce damage to surrounding tissues.

[0066] 8. Universal locking function: The hexagonal absorbable support rod 9 and the titanium alloy spring ring 5 are configured. The titanium alloy spring ring 5 has threads inside the ring, which can cooperate with the titanium alloy locking screw 8 to universally lock the absorbable support rod 9, thereby fixing the fracture site to the greatest extent.

[0067] When the nested assembly internal fixation device for intra-articular fracture of the distal radius provided by the present invention is used, the distal radius fracture is firstly repositioned and aligned, and the fracture end cortex is kept relatively stable after repositioning, and the titanium alloy steel plate 1 assembled with the absorbable polylactic acid ring 6 and the proximal absorbable module 3 is placed close to the bone surface, and it is ensured that the distal lower edge of the titanium alloy steel plate 1 can be close to the watershed edge of the distal end of the radius; the proximal articular surface Kirschner wire hole 11 is close to the articular surface and 2-3 proximal articular surface Kirschner wires are implanted, and the implantation length of the proximal articular surface Kirschner wire does not exceed The distal longitudinal bone cortex is half the depth, and the joint surface is closely attached to the fluoroscopic and pried and reset appropriately; with the Kirschner wire near the joint surface as a parallel reference, 2-4 half-depth titanium alloy screws 4 are implanted through the distal locking hole 12 of the steel plate (parallel and close to the joint surface), and after appropriate adjustment, a titanium alloy screw 4 is implanted through the proximal locking groove 15 of the steel plate; the distal absorbable module 2 is assembled with the titanium alloy spring ring 5 and is not installed for the time being, the fracture window opening and top pressure reduction area 14 is first opened to open the window and top pressure reduction area of ​​the distal radial joint surface, and a hexagonal absorbable support of appropriate length is implanted The front end of the support rod 9 and the absorbable support rod 9 are implanted in the severely collapsed area of ​​the collapsed area of ​​the distal articular surface of the radius. 1-2 absorbable support rods 9 are used according to the collapse range; then the assembly structure of the distal absorbable module 2 and the titanium alloy spring ring 5 is loaded, and two auxiliary Kirschner wires are implanted in the distal Kirschner wire hole 23 for temporary fixation. At this time, only at least one edge of the top of the hexagonal absorbable support rod 9 needs to be in close contact with the bottom of the distal absorbable module 2, and the distal absorption groove 13 of the steel plate with the absorbable polylactic acid ring 6 and the distal module absorbable The receiving groove 21 forms three distal absorbable holes 24; three absorbable screws 7 are respectively implanted in the distal absorbable holes 24, and the top pressure is maintained to reset. Then the titanium alloy locking screw 8 is implanted in the distal module locking hole 22 with the embedded titanium alloy spring ring 5 located between the two distal Kirschner wire holes 23, and the absorbable support rod 9 is appropriately pressurized and the close contact between the absorbable support rod 9 and the distal absorbable module 2 is maintained; finally, the absorbable screw 7 and / or titanium alloy screw 4 of appropriate length are implanted in the proximal module locking hole 31 to fix the proximal absorbable module 3. After completion, the proximal articular surface Kirschner wire implanted in the proximal articular surface Kirschner wire hole 11 and the auxiliary Kirschner wire implanted in the distal Kirschner wire hole 23 are removed.

[0068] The nested assembly internal fixation device provided by the present invention adopts a modular design. The distal end of the titanium alloy steel plate 1 adopts a distal absorbable module 2 which is nested in the fracture window top pressure reduction area 14 of the titanium alloy steel plate 1. A titanium alloy locking screw 8 with a titanium alloy spring ring 5 is implanted for locking, and an absorbable screw 7 with an absorbable polylactic acid ring 6 is configured for fixation. A hexagonal absorbable support rod 9 is configured in the fracture window top pressure reduction area below the distal absorbable module 2. The titanium alloy spring ring 5 with threads in the ring is configured with a titanium alloy locking screw 8 to lock the absorbable support rod 9, and has a universal locking function, which can fix the fracture to the greatest extent. The titanium alloy steel plate 1 is made of titanium alloy material to provide sufficient strength and stability. The special structure of the titanium alloy steel plate 1 designed based on the anatomical morphology of the palmar side of the distal radius can fit closely to the watershed edge of the distal radius, effectively avoiding the risk of the titanium alloy screw 4 entering the radiocarpal joint, and fixing the bone block of the distal radius to the maximum extent; the distal absorbable module 2, the proximal absorbable module 3, the absorbable polylactic acid ring 6, the absorbable screw 7, and the absorbable support rod 9 are all made of polylactic acid absorbable material. By compounding the polylactic acid absorbable material on the titanium alloy steel plate 1, the use of metal materials is reduced. The polylactic acid absorbable material used is degraded in the body and gradually replaced by human tissue, further reducing the patient's pain and economic burden; the internal fixation device appropriately adds part of the polylactic acid absorbable material to the bone defect. The absorbable support rod 9 made of this material serves as an osteogenic induction component, has an osteogenic induction effect, and can promote the healing of the fracture site.

[0069] The nested assembly type internal fixation device provided by the present invention has a design of ultra-distal fixation and convenient window opening and top pressure reduction of the joint surface and can effectively maintain fixation. The nested assembly type internal fixation device constructed by the technology of nested assembly and micro-motion internal fixation can gradually degrade during the fracture healing process, reducing the burden on the patient. First, by nesting and assembling the absorbable parts made of polylactic acid material on the titanium alloy steel plate 1, the use of metal materials is reduced; at the same time, the absorbable material is added to the local component of the locking structure to improve the stress of the internal fixation steel plate during the fracture healing stage, and with the absorption of the degradable materials in different composite parts, the internal fixation steel plate undergoes stress changes during the fracture healing stage, providing a biological fixation steel plate that can micro-move and is more in line with the mechanical environment of fracture healing; in addition, the absorbable support rod 9 made of polylactic acid material is appropriately added to the bone defect to have an osteogenic induction effect; the design of the above-mentioned nested assembly type internal fixation device is simple and easy to use, has better structural support, avoids the re-collapse of the radiocarpal joint, and contributes to the rapid healing of the fracture site. The nested assembly type internal fixation device provided by the present invention solves the problems of weak fixation and easy displacement existing in traditional treatment methods, and has broad application prospects and important social significance.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. Technologies not covered by the present invention can be implemented by existing technologies.

Claims

1. A nested assembly type internal fixation device for distal radial intra-articular fracture, characterized in that: The internal fixation device comprises a titanium alloy steel plate (1) designed based on the anatomical morphology of the palmar side of the distal end of the radius, a distal absorbable module (2) and an absorbable support rod (9), wherein the distal lower edge of the titanium alloy steel plate (1) can be closely attached to the watershed edge of the distal end of the radius, a fracture fenestration top pressure reduction area (14) corresponding to the collapsed area of ​​the distal articular surface of the radius is provided on the titanium alloy steel plate (1), a distal locking hole (12) of the steel plate is provided on the distal side of the fracture fenestration top pressure reduction area (14), and a steel plate proximal end is provided. The plate has a proximal locking groove (15), at least one absorbable support rod (9) is implanted in the collapsed area of ​​the distal articular surface of the radius, and the front end of the absorbable support rod (9) is located in the severely collapsed area of ​​the collapsed area of ​​the distal articular surface of the radius, and a distal absorbable module (2) is fixedly installed in the fracture window top pressure reduction area (14), and the bottom of the distal absorbable module (2) is in close contact with the upper edge of the tail of the absorbable support rod (9); the proximal side of the distal absorbable module (2) is provided with a distal module locking hole (22) The distal module locking hole (22) is used to implant a titanium alloy locking screw (8) with a titanium alloy spring ring (5) to appropriately apply pressure and maintain close contact between the absorbable support rod (9) and the distal absorbable module (2); distal Kirschner wire holes (23) are provided on both sides of the distal module locking hole (22), and the distal Kirschner wire holes (23) are used to temporarily lock the distal absorbable module (2) in the fracture window top pressure reduction area (14); the distal end of the distal absorbable module (2) A distal module absorbable groove (21) is provided at the outer edge, and a steel plate distal absorbable groove (13) is provided on the titanium alloy steel plate (1) at the distal side of the fracture window top pressure reduction area (14). The distal module absorbable groove (21) and the steel plate distal absorbable groove (13) arranged opposite to each other constitute a distal absorbable hole (24). The distal absorbable hole (24) is used to implant an absorbable screw (7) with an absorbable polylactic acid ring (6) and / or a titanium alloy screw (4) with an absorbable polylactic acid ring (6).

2. The nested assembly type internal fixation device for distal radial intra-articular fracture according to claim 1, characterized in that: The upper edge of the tail of the absorbable support rod (9) is located at 1 / 3 of the distance from the proximal end to the distal end of the distal absorbable module (2).

3. The nested assembly internal fixation device for distal radial intra-articular fracture according to claim 1 or 2, characterized in that: The implantation angle of the absorbable support rod (9) is 45° to 75°; the absorbable support rod (9) serving as an osteogenic induction component adopts a hexagonal cross-sectional structure.

4. The nested assembly internal fixation device for distal radial intra-articular fracture according to claim 1, characterized in that: The width of the distal absorbable module (2) is 12 mm to 22 mm, and the edge widths of the titanium alloy steel plates (1) on both sides of the distal absorbable module (2) are 3 mm to 4 mm.

5. The nested assembly type internal fixation device for distal radial intra-articular fracture according to claim 1, characterized in that: The distal locking hole (12) and the proximal locking groove (15) of the steel plate can be respectively implanted with titanium alloy screws (4) to fix the titanium alloy steel plate (1); the proximal locking groove (15) of the steel plate is a U-shaped groove structure, so that the position of the titanium alloy screw (4) at the proximal locking groove (15) of the steel plate can be adjusted.

6. The nested assembly internal fixation device for distal radial intra-articular fracture according to claim 1 or 5, characterized in that: The distal outer edge of the titanium alloy steel plate (1) is provided with a plurality of proximal articular surface Kirschner wire holes (11); the proximal articular surface Kirschner wire holes (11) opening outward are used for implanting proximal articular surface Kirschner wires, which are used for temporarily positioning the titanium alloy steel plate (1) and guiding the titanium alloy screws (4) implanted at the distal locking holes (12) of the steel plate; a spare Kirschner wire hole (17) is provided on the titanium alloy steel plate (1) on the proximal side of the distal locking holes (12) of the steel plate; a spare Kirschner wire hole (17) is provided on the titanium alloy steel plate (1) between the fracture window top pressure reduction area (14) and the proximal locking groove (15) of the steel plate; and a spare Kirschner wire hole (17) is provided at the proximal tail of the titanium alloy steel plate (1).

7. The nested assembly internal fixation device for distal radial intra-articular fracture according to any one of claims 1, 2 and 5, characterized in that: The proximal side of the steel plate proximal locking groove (15) is provided with a strip-shaped steel plate proximal locking area (16), and the distal side of the steel plate proximal locking area (16) is connected to the steel plate proximal locking groove (15); the steel plate proximal locking area (16) is used to embed a proximal absorbable module (3) with a proximal module locking hole (31), and the proximal module locking hole (31) at the distal end of the proximal absorbable module (3) is opened and connected to the steel plate proximal locking groove (15), and a titanium alloy screw (4) and / or an absorbable screw (7) is implanted at the proximal module locking hole (31) to position and fix the proximal absorbable module (3) in the steel plate proximal locking area (16).

8. The nested assembly type internal fixation device for distal radial intra-articular fracture according to claim 7, characterized in that: The edge width of the titanium alloy steel plate (1) on both sides of the distal end of the proximal locking zone (16) of the steel plate is 1 mm to 2 mm, and the edge width of the titanium alloy steel plate (1) on both sides of the proximal end is less than 1 mm, so that the proximal locking zone (16) of the steel plate presents a strip-shaped groove that gradually expands from the distal end to the proximal end of the titanium alloy steel plate (1).

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