Hallux valgus intramedullary nail plate

Abstract

The utility model discloses a hallux valgus intramedullary nail plate, which belongs to the technical field of medical instruments and comprises an intramedullary nail used for being inserted into a metatarsal bone fragment medullary cavity and a fixing plate used for being attached to the inner side of a metatarsal bone head fragment, and the intramedullary nail is cylindrical and extends along the longitudinal axis of a metatarsal bone. A first screw hole used for containing a first bone screw is formed in the middle of the intramedullary nail, and the first screw hole is an inclined screw hole so that the first bone screw can sequentially penetrate through the metatarsal bone shaft fragment and the metatarsal bone head fragment to fix the metatarsal bone shaft fragment and the metatarsal bone head fragment together in a pressurized mode. The plane where the fixing plate is located is parallel to the axis of the intramedullary nail, a second screw hole used for containing a second bone screw to fix metatarsal bone fragments is formed in the fixing plate, the far end of the intramedullary nail is designed in an offset mode, and a preset distance is formed between the plane where the fixing plate is located and the axis of the intramedullary nail. The hallux valgus intramedullary nail plate is firmly fixed, the axial rotation of the metatarsal bone head can be adjusted, and osteonecrosis is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of orthopedic implants, in particular to a hallux valgus intramedullary nail plate. Background Technique

[0002] Hallux valgus is a common foot disorder. Usually, certain factors exert extra pressure on the big toe, causing it to deviate from its natural position and move towards other toes. Specifically, it corresponds to an "inward" deviation of the first metatarsal bone (that is, towards the other foot) and an "outward" deviation of the proximal phalanx of the big toe (that is, towards other toes). The result of this deformation is the formation of a bone prominence from the end of the first metatarsal bone to the medial edge of the foot, commonly known as "hallux valgus". There are various treatment methods for hallux valgus. When non-surgical treatment cannot control the pain, surgical treatment should be considered. Osteotomy is one of the most commonly used methods.

[0003] A typical osteotomy is the transverse osteotomy (also known as the "Bosch osteotomy"). During the operation, the metatarsal bone needs to be cut perpendicular to its longitudinal axis, thus forming two bone fragments: the metatarsal shaft (fragment) and the metatarsal head (fragment). Then, the cut metatarsal head is translated transversely relative to the metatarsal shaft to correct the deformation and realign the metatarsal bone and the proximal phalanx of the big toe. The implants used for this surgical procedure usually consist of two parts: a proximal part inserted into the intramedullary canal of the metatarsal (bone) shaft and a distal part fixed to the metatarsal head. However, currently known implants, such as the locking plate intramedullary nail fixation device disclosed in the utility model patent CN213098242U and the minimally invasive intramedullary fixation device for hallux valgus disclosed in CN218943479U, have poor firmness after being inserted into the metatarsal intramedullary canal. Some of them cannot adjust the axial rotation of the metatarsal head. Therefore, the positioning requirements during the operation are extremely high, and there may be gaps between the bone fragments after the operation, resulting in poor blood supply to the bone blocks and leading to the occurrence of postoperative osteonecrosis. Content of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a hallux valgus intramedullary nail plate that can be firmly fixed, can adjust the axial rotation of the metatarsal head, and can prevent osteonecrosis.

[0005] To solve the above technical problem, the utility model provides the following technical solutions:

[0006] A hallux valgus intramedullary nail plate includes an intramedullary nail for inserting into the intramedullary cavity of the metatarsal shaft fragment and a fixing plate for attaching to the inner side of the metatarsal head fragment, wherein:

[0007] The intramedullary nail is cylindrical and extends along the longitudinal axis of the metatarsal bone. A first screw hole for accommodating a first bone screw is provided in the middle of the intramedullary nail. The first screw hole is an inclined screw hole so that the first bone screw sequentially passes through the metatarsal shaft fragment and the metatarsal head fragment to press and fix the two together;

[0008] The plane where the fixing plate is located is parallel to the axis of the intramedullary nail. The fixing plate is provided with second screw holes for accommodating second bone screws to fix the metatarsal head fragment. The distal end of the intramedullary nail is designed to be offset, so that a preset distance is formed between the plane where the fixing plate is located and the axis of the intramedullary nail.

[0009] Further, the proximal end of the intramedullary nail gradually tapers proximally;

[0010] And / or, the middle part of the intramedullary nail has a smaller size than the distal part.

[0011] Further, the first bone screw is a compression locking screw;

[0012] And / or, the tail of the first bone screw is provided with a tapered enlarged section;

[0013] And / or, the first bone screw is of a hollow design, and a Kirschner wire hole is arranged inside the first bone screw;

[0014] And / or, the included angle between the axis of the first screw hole and the axis of the intramedullary nail is 20 - 40 degrees.

[0015] Further, the front part of the first bone screw is provided with a first external thread for cooperating with the metatarsal head fragment, the middle and rear part of the first bone screw is provided with a second external thread for cooperating with the metatarsal shaft fragment, and a smooth rod section is arranged on the first bone screw between the first external thread and the second external thread;

[0016] Or, the first bone screw is provided with a thread with a gradually changing and continuous pitch.

[0017] Further, the distal end of the intramedullary nail is a cone that gradually widens distally.

[0018] Further, when viewed from a side view, the distal end of the intramedullary nail is provided with an inclined cutting surface, and the fixing plate is connected to the end of the inclined cutting surface, thereby forming the offset design.

[0019] Further, the preset distance is 1 mm - 10 mm.

[0020] Further, the intramedullary nail is of a hollow design, and a Kirschner wire hole extending along the axial direction is arranged at the proximal end of the intramedullary nail.

[0021] Further, the width of the fixing plate is the same as the width of the distal end of the intramedullary nail.

[0022] Further, the second bone screw is a locking screw;

[0023] And / or, the second screw hole is a countersunk hole;

[0024] And / or, the number of the second screw holes is one or two and they are arranged at intervals along the length direction of the fixing plate.

[0025] The utility model has the following beneficial effects:

[0026] The hallux valgus intramedullary nail plate of the utility model includes an intramedullary nail for inserting into the medullary cavity of the metatarsal shaft fragment and a fixing plate for attaching to the inner side of the metatarsal head fragment. The intramedullary nail is cylindrical and extends along the longitudinal axis of the metatarsal bone, realizing a simpler axial rotation adjustment after the intramedullary nail is inserted into the medullary cavity, capable of adjusting the axial rotation of the metatarsal head, reducing the positioning requirements during the operation, and the shape of the intramedullary nail does not change when it undergoes axial rotation, so that when the intramedullary nail rotates in the medullary cavity during the operation, it will not cause additional shape changes to the surrounding bone; a first screw hole for accommodating a first bone screw is provided in the middle of the intramedullary nail, and the first screw hole is an inclined screw hole so that the first bone screw sequentially passes through the metatarsal shaft fragment and the metatarsal head fragment to press and fix the two together. Compared with the traditional transverse osteotomy technique of driving a single screw, the first bone screw sequentially passes through the metatarsal shaft fragment and the metatarsal head fragment, preventing the intramedullary nail from rotating and displacing after obtaining a suitable position, and realizing a certain amount of pressurization, being more stable and firmly fixed, preventing the generation of gaps between the two fragments, ensuring the contact between the two fragments, avoiding poor blood supply, and preventing bone necrosis; the plane where the fixing plate is located is parallel to the axis of the intramedullary nail, and a second screw hole for accommodating a second bone screw to fix the metatarsal head fragment is provided on the fixing plate, facilitating the fixing of the metatarsal head fragment by the fixing plate, and being firmly fixed with only a few bone screws, controlling the bone mass loss; the distal end of the intramedullary nail is of an offset design, so that a preset distance is formed between the plane where the fixing plate is located and the axis of the intramedullary nail. Considering the different conditions of the patient's metatarsal bone, the distal end of the intramedullary nail is of an offset design. The increase in the offset amount (i.e., the preset distance) will make the metatarsal head away from the longitudinal axis of the intramedullary nail, facilitating the use during the operation. Description of the Drawings

[0027] Figure 1 is a three-dimensional structural schematic diagram of the hallux valgus intramedullary nail plate of the utility model;

[0028] Figure 2 is a side view of the hallux valgus intramedullary nail plate of the utility model;

[0029] Figure 3 is a front view of the hallux valgus intramedullary nail plate of the utility model;

[0030] Figure 4 is a schematic diagram of the use state of the hallux valgus intramedullary nail plate of the utility model. Detailed Embodiments

[0031] To make the technical problems, technical solutions and advantages to be solved by the utility model clearer, the following will be described in detail with reference to the drawings and specific embodiments.

[0032] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0033] In patients with hallux valgus, the metatarsal head deflects toward the medial side of the foot, causing bone protrusion and causing pain in the patient. Therefore, the metatarsal can be cut transversely to form a metatarsal shaft fragment 10 and a metatarsal head fragment 20. After the positions of the two bone fragments are rearranged, the longitudinal axis of the metatarsal is roughly in line with the first phalanx. In order to fix this arrangement, the hallux valgus intramedullary nail plate of the utility model can be used.

[0034] The utility model provides a hallux valgus intramedullary nail plate, such as Figures 1-4 As shown, it includes an intramedullary nail 1 for inserting into the medullary cavity of the metatarsal shaft fragment 10 and a fixing plate 2 for attaching to the inner side of the metatarsal head fragment 20, wherein:

[0035] The intramedullary nail 1 is cylindrical and extends along the longitudinal axis of the metatarsal bone. A first screw hole 11 for accommodating a first bone screw 3 is provided in the middle of the intramedullary nail 1. The first screw hole 11 is an oblique screw hole so that the first bone screw 3 sequentially passes through the metatarsal shaft fragment 10 and the metatarsal head fragment 20 to pressurize and fix the two together.

[0036] The plane where the fixing plate 2 is located is parallel to the axis of the intramedullary nail 1 (that is, the normal line of the plane where the fixing plate 2 is located is orthogonal to the longitudinal axis of the metatarsal bone). The fixing plate 2 is provided with a second screw hole 21 for accommodating a second bone screw 4 to fix the metatarsal head fragment 20. The distal end of the intramedullary nail 1 is offset so that a preset distance L is formed between the plane where the fixing plate 2 is located and the axis of the intramedullary nail 1.

[0037] During the operation, the metatarsal bone is firstly transversely divided into two parts, the metatarsal shaft fragment 10 and the metatarsal head fragment 20, and the metatarsal head fragment 20 is translated to reduce the protrusion of the first metatarsophalangeal joint and make the longitudinal axis of the metatarsal shaft fragment 10 roughly colinear with the first phalanx. In order to fix this positional relationship for a long time, the hallux valgus intramedullary nail plate of the utility model is required, that is, the intramedullary nail 1 is inserted into the medullary cavity of the metatarsal shaft fragment 10, and is rotated and adjusted to a suitable position so that the fixing plate 2 is attached to the inner side of the metatarsal head fragment 20, and then the second bone screw 4 is taken and driven into the designated position along the second screw hole 21 to fix the metatarsal head fragment 20, and then the first bone screw 3 is taken and passed through the proximal end of the metatarsal shaft fragment 10 and the first screw hole 11 in sequence, and then the metatarsal shaft fragment 10 is passed out from the distal end and penetrated into the metatarsal head fragment 20, so that the metatarsal shaft fragment 10 and the metatarsal head fragment 20 are pressurized and fixed together, and the implantation is completed (see Figure 4). In the present utility model, the positions and directions of the first bone screw 3 and the second bone screw 4 are calculated in advance to prevent interference after the bone screws are inserted.

[0038] The hallux valgus intramedullary nail plate of the present utility model includes an intramedullary nail for inserting into the medullary cavity of the metatarsal shaft fragment and a fixing plate for attaching to the inner side of the metatarsal head fragment. The intramedullary nail is cylindrical and extends along the longitudinal axis of the metatarsal bone, realizing a simpler axial rotation adjustment after the intramedullary nail is inserted into the medullary cavity, capable of adjusting the axial rotation of the metatarsal head, reducing the positioning requirements during the operation, and the shape of the intramedullary nail does not change when it undergoes axial rotation, so that when the intramedullary nail rotates in the medullary cavity during the operation, it will not cause additional shape changes to the surrounding bone; a first screw hole for accommodating the first bone screw is provided in the middle of the intramedullary nail, and the first screw hole is an inclined screw hole so that the first bone screw sequentially passes through the metatarsal shaft fragment and the metatarsal head fragment to press-fix the two together. Compared with the traditional transverse osteotomy technique of driving a single screw, the first bone screw sequentially passes through the two parts of the metatarsal shaft fragment and the metatarsal head fragment, preventing the intramedullary nail from rotating and displacing after obtaining the appropriate position, and achieving a certain amount of compression, being more stable and firmly fixed, preventing the generation of gaps between the two fragments, ensuring contact between the two fragments, avoiding poor blood supply, and preventing bone necrosis; the plane where the fixing plate is located is parallel to the axis of the intramedullary nail, and a second screw hole for accommodating the second bone screw to fix the metatarsal head fragment is provided on the fixing plate, facilitating the fixing of the metatarsal head fragment by the fixing plate, and being firmly fixed with only a few bone screws, controlling bone mass loss; the distal end of the intramedullary nail is an offset design, so that a preset distance is formed between the plane where the fixing plate is located and the axis of the intramedullary nail. Considering the different metatarsal conditions of patients, the distal end of the intramedullary nail is an offset design, and an increase in the offset amount (i.e., the preset distance) will make the metatarsal head away from the longitudinal axis of the intramedullary nail, facilitating intraoperative use. The present utility model is applicable to hallux valgus osteotomy orthopedic surgery.

[0039] As Figures 1-3 shown, the proximal end of the intramedullary nail 1 can gradually taper proximally, facilitating insertion into the medullary cavity of the metatarsal shaft fragment 10. The middle dimension of the intramedullary nail 1 can be smaller than the distal dimension to form a press fit at the distal end of the intramedullary nail 1, making it not easy to have prosthesis loosening and having a good postoperative effect. The distal end of the intramedullary nail 1 can be a (circular) conical shape that gradually widens distally, better forming a press fit at the distal end of the intramedullary nail 1 and having a better postoperative effect.

[0040] As Figures 1-4 shown, the first bone screw 3 is preferably a compression locking screw, having better firmness and better pressing and fixing the metatarsal shaft fragment 10 and the metatarsal head fragment 20 together; in some embodiments, an ordinary screw can also be used instead of the compression locking screw. A tapered swelling section 31 can be provided at the tail of the first bone screw 3 to preferably provide a pressing force and better press-fix the metatarsal shaft fragment 10 and the metatarsal head fragment 20 together.

[0041] The first bone screw 3 can be of a hollow design. A Kirschner wire hole (not shown) is provided inside the first bone screw 3 to facilitate positioning by passing a Kirschner wire through it. The angle α between the axis of the first screw hole 11 and the axis of the intramedullary nail 1 can be 20 - 40 degrees, such as 30 degrees, 35 degrees, 38 degrees, etc., which is convenient for the first bone screw 3 to penetrate through the distal end of the metatarsal shaft fragment 10 and into the metatarsal head fragment 20, and has good firmness.

[0042] Preferably, the front part of the first bone screw 3 is provided with a first external thread 32 for cooperating with the metatarsal head fragment 20, and the middle and rear parts of the first bone screw 3 are provided with a second external thread 33 for cooperating with the metatarsal shaft fragment 10. A smooth rod section 34 can be provided between the first external thread 32 and the second external thread 33 on the first bone screw 3 to achieve compression. And when the first bone screw 3 is driven into the designated position and there is an exposure between the metatarsal head fragment 20 and the metatarsal shaft fragment 10, the setting of the smooth rod section 34 can preferably avoid soft tissue irritation. It can be imagined that the first bone screw 3 can also be provided with a thread with a gradually changing and continuous pitch, so that compression can also be achieved when passing through the two bone fragments.

[0043] The offset design of the distal end of the intramedullary nail 1 can adopt various implementation methods that are easy to think of by those skilled in the art. For example, the distal end of the intramedullary nail is spiral-shaped, etc. However, for the convenience of implementation, the present utility model preferably adopts the following structural form:

[0044] As Figure 2 shown, from the side view, the distal end of the intramedullary nail 1 is provided with an inclined cutting surface 12, and the fixing plate 2 is connected to the end of the inclined cutting surface 12, thereby forming an offset design. This design method is convenient for processing and manufacturing and has good firmness.

[0045] As Figure 4 shown, the preset distance L can be 1 mm - 10 mm, such as 3 mm, 5 mm, 7 mm, etc., with a wider adaptation range. As Figure 1 shown, the intramedullary nail 1 can be of a hollow design. The proximal end of the intramedullary nail 1 is provided with a Kirschner wire hole (not shown) extending along the axis direction to facilitate guiding the placement of the intramedullary nail 1. During the operation, a Kirschner wire can be used to locate the appropriate position and direction first, and then the intramedullary nail 1 is driven through the Kirschner wire into the medullary cavity of the metatarsal shaft fragment 10 along the Kirschner wire hole.

[0046] The width of the fixing plate 2 can be different from the width of the distal end of the intramedullary nail 1. However, as Figure 3 shown, to reduce the overall volume and achieve minimally invasive implantation, the width of the fixing plate 2 can be the same as the width of the distal end of the intramedullary nail 1. The second bone screw 4 can be a locking screw. The second screw hole 21 can be a countersunk hole to prevent the head of the second bone screw 4 from protruding from the fixing plate 2 and avoid soft tissue irritation. The number of the second screw holes 21 can be 1 or 2 and are spaced along the length direction of the fixing plate 2 to preferably fix the metatarsal head fragment 20 with good firmness.

[0047] In summary, the present utility model provides a hallux valgus intramedullary nail plate suitable for fixing the metatarsal shaft fragments and metatarsal head fragments generated after transverse osteotomy of the metatarsal bone. The intramedullary nail for insertion into the medullary cavity of the metatarsal shaft fragment is a rotating body centered on the longitudinal axis of the metatarsal bone (i.e., the center line of the intramedullary nail is collinear with the longitudinal axis of the metatarsal bone), and the longitudinal axis of the metatarsal bone is parallel to the plane where the fixing plate is located. The fixing plate is planar and shaped to be fixed to the inner side of the metatarsal head fragment. All screw holes in the present utility model can be in threaded fit with their corresponding bone screws.

[0048] The above is the preferred embodiment of the present utility model. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle described in the present utility model, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present utility model.

Claims

1. An intramedullary nail plate for hallux valgus, characterized in that: The invention comprises an intramedullary nail for inserting into the medullary cavity of the metatarsal shaft fragment and a fixing plate for attaching to the inner side of the metatarsal head fragment, wherein: The intramedullary nail is cylindrical and extends along the longitudinal axis of the metatarsal bone. A first screw hole for accommodating a first bone screw is provided in the middle of the intramedullary nail. The first screw hole is an oblique screw hole so that the first bone screw can sequentially pass through the metatarsal shaft fragment and the metatarsal head fragment to pressurize and fix the two together. The plane where the fixing plate is located is parallel to the axis of the intramedullary nail. The fixing plate is provided with a second screw hole for accommodating a second bone screw to fix the metatarsal head fragment. The distal end of the intramedullary nail is offset so that a preset distance is formed between the plane where the fixing plate is located and the axis of the intramedullary nail.

2. The hallux valgus intramedullary nail plate according to claim 1, characterized in that: The proximal end of the intramedullary nail gradually tapers proximally; And / or, the middle dimension of the intramedullary nail is smaller than the distal dimension.

3. The hallux valgus intramedullary nail plate according to claim 1, characterized in that: The first bone screw is a compression locking screw; And / or, the tail of the first bone screw is provided with a conical expansion section; And / or, the first bone screw is hollow in design, and a Kirschner wire hole is provided in the first bone screw; And / or, the angle between the axis of the first screw hole and the axis of the intramedullary nail is 20-40 degrees.

4. The hallux valgus intramedullary nail plate according to claim 1, characterized in that: The front portion of the first bone screw is provided with a first external thread for matching with the metatarsal head fragment, the middle and rear portion of the first bone screw is provided with a second external thread for matching with the metatarsal shaft fragment, and the first bone screw is provided with a bare rod section between the first external thread and the second external thread; Alternatively, the first bone screw is provided with a continuous thread with a gradually changing pitch.

5. The hallux valgus intramedullary nail plate according to claim 3, characterized in that: The distal end of the intramedullary nail is in a tapered shape that gradually widens toward the distal side.

6. The hallux valgus intramedullary nail plate according to any one of claims 1 to 5, characterized in that: Seen from the side view, the distal end of the intramedullary nail is provided with a chamfered surface, and the fixing plate is connected to the distal end of the chamfered surface, thereby forming the offset design.

7. The hallux valgus intramedullary nail plate according to claim 6, characterized in that: The preset distance is 1mm-10mm.

8. The hallux valgus intramedullary nail plate according to claim 6, characterized in that: The intramedullary nail is hollow in design, and a Kirschner wire hole extending along the axial direction is provided at the proximal end of the intramedullary nail.

9. The hallux valgus intramedullary nail plate according to claim 6, characterized in that: The width of the fixing plate is the same as the distal width of the intramedullary nail.

10. The hallux valgus intramedullary nail plate according to claim 6, characterized in that: The second bone screw is a locking screw; And / or, the second screw hole is a countersunk hole; And / or, the number of the second screw holes is 1 or 2 and they are arranged at intervals along the length direction of the fixing plate.

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