An interosseous bone lengthening aid with a telescopic mesh support

Abstract

A bone lengthening auxiliary device with a telescopic mesh support for assisting interosseous growth, on the basis of the current bone lengthening external fixation device, a mesh telescopic support made of magnesium material is fixed between the two ends of the osteotomy by the first bone external fixation needle or steel needle, and the first bone external fixation needle or steel needle for fixation is installed on the external fixation frame. The support can gradually expand with the lengthening of the two ends of the osteotomy, forming a mesh structure, providing a porous mesh support for guiding interosseous tissue regeneration between the two ends of the osteotomy, and improving the osteogenesis efficiency and strength during bone lengthening. The magnesium metal material can be degraded automatically in the later stage, and the degradation process can promote osteogenesis. The bone lengthening external fixation device is simple and convenient to operate during adjustment, with scales to ensure the adjustment accuracy; the support is prepared by 3D printing, which can be designed individually for different patients and different parts of the bone shape, and the mesh pore size can be controlled, with good adaptability and good bone lengthening effect.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a bone lengthening auxiliary device with a retractable mesh support for assisting interbone growth. Background Art

[0002] Bone lengthening is also called distraction osteogenesis, which involves cutting the bone while preserving the soft tissue and blood supply. A special traction device is used to fix the two ends, and the tensile stress law is applied to gradually apply tension to slowly stretch the bone segments, continuously stimulating the body's tissues, stimulating the regenerative potential of human tissues, and forming new bone in the osteotomy gap, thus achieving the purpose of bone regeneration.

[0003] The instruments used for lengthening surgeries currently operate on essentially the same principle: a primary external fixator secures the two broken bones and adjusts the distance between them to achieve interosseous distance adjustment. Once interosseous regeneration is complete, bone lengthening is achieved. However, during the lengthening process, bone tissue regeneration is slow, weak, and even nonunion is a common complication, making it a major complication of bone lengthening surgery. Prolonged nonunion or fibrous healing of the cut ends can make it impossible to remove the external fixator, resulting in weight-bearing problems or the need for additional surgery, placing a significant burden on patients, their families, and society. Summary of the Invention

[0004] In response to the problems existing in the above-mentioned background technology, the present invention proposes a bone lengthening auxiliary device with a retractable mesh support member to assist interbone growth. The mesh support member ensures the stability of the bone gap, while promoting the growth of interbone tissue and improving the therapeutic effect of bone lengthening.

[0005] A bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth, comprising an external fixator, a first external bone fixation pin, a second external bone fixation pin, and a mesh support member, wherein the first external bone fixation pin and the second external bone fixation pin are respectively arranged on the external fixator, and both ends of the mesh support member are connected to the second external bone fixation pin;

[0006] The bone lengthening auxiliary device is fixed to the bone to be lengthened via a first external bone fixation pin, and the mesh support is placed in the bone gap via a second external bone fixation pin;

[0007] The mesh support member includes a mesh outer wall and a support structure, the support structure is compressible and extendable, and is arranged on the inner side of the mesh outer wall. Both ends of the support structure are provided with connecting ends, which are connected to the second external bone fixation pin to fix the mesh support member;

[0008] The mesh support member is made of magnesium material.

[0009] Furthermore, the first external bone fixation pin and the second external bone fixation pin are both mounted on the external fixator via a sliding fixing member.

[0010] Furthermore, the sliding fixing member cooperates with the graduated sliding groove of the external fixator, and is fixed after being adjusted left and right according to the position of the bone, so that the first external bone fixation pin and the second external bone fixation pin are installed at corresponding positions of the bone.

[0011] Furthermore, the support structure of the mesh support member is a telescopic structure, which is telescopic according to the movement of the second external bone fixation pins connected at both ends on the external fixator, and at the same time, the support structure drives the mesh outer wall to expand.

[0012] Furthermore, the connection end of the mesh support is a circular hole.

[0013] Furthermore, the top end of the second external bone fixation pin is provided with a hook-shaped structure, which cooperates with the circular hole at the connecting end of the mesh support member to achieve connection and fixation.

[0014] Furthermore, the mesh holes on the mesh outer wall have a diameter of 600 μm-1000 μm.

[0015] Furthermore, the external fixator is a single-arm fixator or a ring fixator.

[0016] Furthermore, the mesh support is personalized according to the actual bone structure using 3D printing.

[0017] The beneficial effects achieved by the present invention are as follows: (1) the device is fixed to the two separated bone segments by the first external bone fixation pin, and the second external bone fixation pin is fixedly arranged corresponding to the bone gap, and the mesh support is placed in the gap of the osteotomy to achieve support between the two bone segments; (2) due to the use of magnesium material, bone cells can grow on the porous mesh scaffold formed by the mesh support, guiding the regeneration of interosseous tissue, growing faster, improving the growth efficiency and effect during bone lengthening, and ensuring the strength of the growing bone structure; (3) through the design of the retractable mesh support, when the width of the bone gap is adjusted, the mesh support is retracted and retracted together, and the two ends remain in a state of resisting the broken bone section, ensuring the support effect and interosseous tissue growth; (4) the first external bone fixation pin and the second external bone fixation pin are movably installed on the external fixator, and the operation is simple and convenient when adjusting, and the scale is provided to ensure the adjustment accuracy; (5) each component is prepared by 3D printing, so that the device can be designed for different conditions of different patients, with good adaptability and good final bone lengthening effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the bone lengthening auxiliary device described in an embodiment of the present invention.

[0019] Figure 2 Schematic diagram of the mesh support member described in an embodiment of the present invention.

[0020] Figure 3 Schematic diagram of the support structure of the mesh support member described in an embodiment of the present invention.

[0021] Figure 4 Schematic diagram of the ring-type fixing frame according to an embodiment of the present invention.

[0022] In the figure, 1-external fixator, 2-first external bone fixation pin, 3-second external bone fixation pin, 4-mesh support member, 41-mesh outer wall, 42-support structure, 5-sliding fixation member, 6-sliding groove. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] A bone lengthening assisting device with a retractable mesh support for assisting interbone growth, with reference to Figure 1 , including an external fixator 1, a first external bone fixation pin 2, a second external bone fixation pin 3 and a mesh support member 4. The first external bone fixation pin 2 and the second external bone fixation pin 3 are respectively arranged on the external fixator 1. Specifically, the first external bone fixation pin 2 is divided into two places, each of which contains two screws or fixing steel pins, which are respectively arranged on both sides of the external fixator 1. The second external bone fixation pin 3 is also divided into two sections, which are arranged on the external fixator 1 between the first external bone fixation pins 2 on both sides. The two ends of the mesh support member 4 are respectively connected to the second external bone fixation pins 3 at both ends.

[0025] The bone lengthening auxiliary device is fixed to the two bone segments broken during the bone lengthening operation through the first external bone fixation pin 2 , and the mesh support member 4 is placed in the bone gap of the broken bones through the second external bone fixation pin 3 .

[0026] The first external bone fixation pin 2 and the second external bone fixation pin 3 can both be screws or fixed steel pins.

[0027] Reference Figure 2 The mesh support 4 includes a mesh outer wall 41 and a support structure 42. The support structure 42 can be compressed and extended. Figure 3 The telescopic rod structure shown can also employ other structures that achieve similar functions. These structures are disposed on the inner side of the mesh outer wall 41. The support structure 42 has connecting ends at both ends that connect to the second external fixation pins 3 to secure the mesh support member 4. In this embodiment, the connecting ends are designed as circular holes, and the corresponding hook-shaped structures are provided at the tops of the second external fixation pins 3, which engage with the circular holes of the connecting ends and hook into them to achieve secure connection. Other detachable connection methods, such as snap-fit ​​or interlocking structures, can also be employed.

[0028] The mesh support 4 is made of magnesium material, which is conducive to the growth of bone tissue, and the mesh support 4 can also be used as a framework for bone tissue growth. Since the hollow cylindrical structure is formed by the mesh outer wall 41, and the bone structure is similar, the bone cells can directly adhere to the mesh outer wall 41 for regeneration, and finally directly form regenerated bone.

[0029] During bone lengthening, placing the mesh support 4 between the two ends of the cut bone provides favorable conditions for bone cells to adhere, proliferate, differentiate, and mineralize bone on the basis of pulling the bone, which greatly improves the speed and strength of bone formation. Magnesium metal material has a density and elastic modulus close to that of cortical bone, and greater toughness than ceramic biomaterials. Compared with the currently used inert metals (such as titanium alloy), magnesium metal can effectively avoid the "stress barrier" effect caused by implantation in the body. At the same time, the magnesium ions generated by the degradation of magnesium metal in the body also have biological activity that is conducive to fracture healing. Currently, magnesium metal has been proven to promote osteogenesis and angiogenesis, and it is a biodegradable material that does not require secondary removal. The suitable pore size of the mesh support 4 also promotes the regeneration of bone. Therefore, the stretchable magnesium metal mesh support 4 can significantly improve the efficiency of bone formation and reduce complications such as nonunion and refracture.

[0030] The first bone external fixation needle 2 and the second bone external fixation needle 3 are both installed on the external fixation frame 1 through the sliding fixing piece 5. The sliding fixing piece 5 cooperates with the sliding groove 6 with scales on the external fixation frame 1, and is connected by embedding. At the same time, the two can be fixed by the setting of buckles or other limiting pieces. During use, the positions of the first bone external fixation needle 2 and the second bone external fixation needle 3 are adjusted left and right according to the position of the bone, and then fixed, so that the first bone external fixation needle 2 and the second bone external fixation needle 3 can be installed into the corresponding positions of the bone. Then, during the treatment period, the sliding groove 6 can also be directly adjusted with high precision through the sliding fixing piece 5, and the movement of the first bone external fixation needle 2 is controlled to pull apart the two ends of the fractured bone, and the second bone external fixation needle 3 is moved to further control the stretching of the mesh support 4, so that the two ends of the mesh support 4 remain against the cross section of the fractured bone, ensuring the supporting effect and the promotion effect of the interosseous tissue growth.

[0031] The support structure 42 of the mesh support 4 is a telescopic structure, which is telescoped according to the movement of the second bone external fixation needle 3 connected at both ends on the external fixation frame 1, and the mesh outer wall 41 is expanded by the support structure 42. Figure 3 The support structure 42 in the embodiment is a telescopic rod, which has a certain sliding friction on the rod, so that when the second bone external fixation needle 3 is fixed, the length of the telescopic rod does not change, and remains stable to achieve the supporting effect.

[0032] The pore size of the mesh holes on the mesh outer wall is 800-1000 μm.

[0033] The external fixator 1 can be a single-arm type fixator or a ring type fixator. Figure 1 The ring type fixing frame is composed of multiple single-arm fixing frames connected in a ring shape, similar to Figure 2 Although the second external bone fixation pin 3 is not shown, it can be understood that each fixation frame is fixed to the bone in a circumferential manner through the first external bone fixation pin 2, and the second external bone fixation pin 3 is connected to a single mesh support member 4 located in the center of the annular structure. Although more equipment is used, the support effect is better.

[0034] The mesh support member 4 in the bone lengthening auxiliary device is made by 3D printing according to the actual bone lengthening needs, so that the device can be designed according to the different conditions of different patients and the actual bone structure, with good adaptability and good final bone lengthening effect.

[0035] During use, the bone lengthening assist device, a retractable mesh support member 4 made of magnesium material, is secured between the two ends of the osteotomy using a first external fixation pin 2. The first external fixation pin 2 is mounted on an external fixator 1. This mesh support member 4 gradually expands as the osteotomy ends extend, forming a mesh structure. This porous mesh scaffold between the two ends of the osteotomy guides interosseous tissue regeneration, improving the efficiency and strength of bone formation during bone lengthening. The magnesium metal material self-degrades later, promoting bone formation during degradation. Adjustment of the device is simple and convenient, with a scale ensuring precise adjustment. 3D printing allows for personalized design for different bone shapes in different patients, while also controlling the mesh aperture, resulting in excellent adaptability and bone lengthening results.

[0036] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed in the present invention should be included in the protection scope recorded in the claims.

Claims

1. A bone lengthening assisting device with a retractable mesh support member for assisting interosseous growth, characterized in that: The bone lengthening auxiliary device includes an external fixator, a first external bone fixation pin, a second external bone fixation pin and a mesh support member, wherein the first external bone fixation pin and the second external bone fixation pin are respectively arranged on the external fixator, and both ends of the mesh support member are connected to the second external bone fixation pin; The bone lengthening auxiliary device is fixed to the bone to be lengthened via a first external bone fixation pin, and the mesh support is placed in the bone gap at both ends of the osteotomy via a second external bone fixation pin; The mesh support member includes a mesh outer wall and a support structure, which is arranged on the inner side of the mesh outer wall. Both ends of the support structure are provided with connecting ends, which are connected to the second external bone fixation pin to fix the mesh support member; The support structure of the mesh support member is a telescopic structure, which is telescopic according to the movement of the second bone external fixation pins connected at both ends on the external fixator, and at the same time, the support structure drives the mesh outer wall to expand; The mesh support is made of magnesium material and gradually expands as the bone gap at both ends of the osteotomy increases to form a mesh structure, forming a porous mesh scaffold between the two ends of the osteotomy to guide the regeneration of interosseous tissue.

2. A bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth according to claim 1, characterized in that: The first external bone fixation pin and the second external bone fixation pin are screws or fixed steel pins.

3. The bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth according to claim 1, characterized in that: The first external bone fixation pin and the second external bone fixation pin are both slidably mounted on the external fixator.

4. The bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth according to claim 3, characterized in that: The sliding fixing piece cooperates with the sliding groove with scale of the external fixator, and is fixed after being adjusted left and right according to the position of the bone, so that the first external bone fixation pin and the second external bone fixation pin are installed in the corresponding positions of the bone.

5. The bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth according to claim 1, characterized in that: The connection end of the mesh support is a circular hole.

6. The bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth according to claim 5, characterized in that: The top end of the second external bone fixation pin is provided with a hook-shaped structure, which cooperates with the circular hole at the connecting end of the mesh support member to achieve connection and fixation.

7. The bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth according to claim 1, characterized in that: The pores on the mesh outer wall have a diameter of 600 μm to 1000 μm.

8. The bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth according to claim 1, characterized in that: The external fixator is a single-arm fixator or a ring fixator.

9. The bone lengthening auxiliary device with a retractable mesh support member for assisting interbone growth according to claim 1, characterized in that: The mesh support is personalized according to the actual bone structure using 3D printing.

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