A self-expanding angled bone plate fixation system and method for femoral neck fractures

Abstract

The application provides a self-expanding angle type bone plate fixing system and method for femoral neck fracture, and belongs to the technical field of orthopedic medical instruments, and comprises an angle type bone plate, a self-expanding compression screw, a self-expanding locking screw and a visible and controllable self-expanding platform; the self-expanding compression screw is inserted into a pre-hole formed in the femoral neck; one end of the angle type bone plate is fixedly connected with the self-expanding compression screw; the self-expanding locking screw is used for fixing the angle type bone plate and the femur; and the visible and controllable self-expanding platform is used for controlling the expansion size of the self-expanding compression screw. The self-expanding compression screw and the self-expanding locking screw can firmly fix the angle type bone plate on the femur, the situation of screw backout and femoral head rotation can be avoided, the size of the self-expanding can be accurately controlled by using the visible and controllable self-expanding platform, and the expansion is prevented from being too large to damage the blood supply of the medullary cavity.

Description

Technical Field

[0001] This invention relates to the field of orthopedic medical device technology, specifically to a self-expanding angled bone plate fixation system and method for femoral neck fractures. Background Technology

[0002] Femoral neck fractures are a common type of fracture in clinical practice, and are generally treated with internal fixation. Angled plate fixation is a technique used in internal fixation of fractures. This technique uses angled plates in conjunction with compression screws and locking screws to form a unified structure with the proximal femur. This can control rotation and shear forces at the fracture ends to a certain extent, preventing rotational displacement at the fracture site, increasing the stability of fracture fixation, improving fracture healing rates, and reducing infection rates, thus providing a more biologically sound approach to fracture treatment. However, conventional clinical treatment of long bone fractures of the femoral neck still has the following limitations:

[0003] 1. Using three hollow nails for treatment can easily lead to nail retraction, protrusion, and Z-shaped effects, resulting in surgical failure and causing secondary harm to the patient.

[0004] 2. Although the conventional angle plate treatment method does not cause screw retraction, its anti-rotation effect is weak. The femoral head is prone to rotation during the recovery process, leading to femoral deformity and seriously affecting the patient's life.

[0005] 3. Intramedullary nailing can effectively prevent nail retraction and rotation, but it requires opening and reaming the medullary cavity before inserting the intramedullary nail. This puts significant pressure on the patient's medullary cavity, affecting blood supply to the medulla and potentially causing respiratory distress. In addition, intramedullary nailing involves more instruments and is a more complex procedure, requiring a higher level of skill from the surgeon.

[0006] To address the aforementioned problems, this invention provides a self-expanding angled bone plate fixation system for femoral neck fractures and its method of use. Summary of the Invention

[0007] The purpose of this invention is to provide a controllable self-expanding intramedullary nail internal fixation system and method for long bone fractures.

[0008] To solve the above-mentioned technical problems, the objective of this invention is achieved as follows:

[0009] A self-expanding angled bone plate fixation system for femoral neck fractures includes: an angled bone plate, a self-expanding compression screw, a self-expanding locking screw, and a visually controllable self-expanding platform;

[0010] The angled bone plate includes a mating section and a plate body that are fixedly connected; the mating section has a hollow columnar structure and the cross-section of the hollow part is not circular; the plate body is provided with a plurality of screw mating holes evenly distributed on it.

[0011] One end of the self-expanding compression screw is adapted to be inserted into the mating section; the other end is inserted into the pre-hole of the femoral neck and is provided with an expandable part.

[0012] The self-expanding locking screw engages with the screw hole to secure the angled bone plate;

[0013] One end of the visual and controllable self-expanding platform is connected to the self-expanding pressure screw, and a display mechanism is provided to display the expansion size of the self-expanding pressure screw.

[0014] Based on the above scheme and as a preferred embodiment, the self-expanding pressure screw includes a proximal section, an expandable support, and a distal section; the expandable support is disposed between the proximal section and the distal section; the proximal section and the distal section are hollow to form an operating cavity, and a distal internal thread is formed on the inner wall of the operating cavity of the distal section, and a proximal internal thread is formed on the inner wall of the operating cavity of the proximal section; a drive screw is disposed inside the operating cavity; the two ends of the drive screw are provided with opposite threads that connect to the proximal internal thread and the distal internal thread respectively; the proximal section is adaptedly inserted into the mating section.

[0015] Based on the above scheme and as a preferred embodiment of the above scheme, the visible and controllable self-expanding platform includes a worm, a worm wheel, and a housing; the worm and the worm wheel are meshed inside the housing; both ends of the worm extend outside the housing, one end is connected to the self-expanding pressure screw, and the other end is used to control rotation; a worm wheel shaft is fixedly provided at the center of the worm wheel, and a pointer is fixedly provided at the other end of the worm wheel shaft, with a corresponding scale on the pointer.

[0016] Based on the above solution and as a preferred embodiment, a limit rod is provided on the housing; the limit rod can lock the worm gear.

[0017] Based on the above scheme and as a preferred embodiment of the above scheme, the expandable support includes several expandable connecting plates, each of which includes two connecting plates. The two connecting plates are flexibly connected, and the ends of the two connecting plates are respectively flexibly connected to the proximal segment and the distal segment.

[0018] Based on the above scheme and as a preferred embodiment of the above scheme, the self-expanding locking screw includes a screw body and an opening bracket; the opening bracket is disposed at the end of the screw body and is driven to expand by a screw core disposed inside the screw body; the opening bracket is provided with a drug release hole.

[0019] A method of using the above-mentioned self-expanding angled plate fixation system for femoral neck fractures includes the following steps:

[0020] Step 1: Preoperative preparation: Examine the length of the patient's femoral head and neck under CT or X-ray, and select an appropriate compression screw for surgery based on the length of the patient's femoral head and neck;

[0021] Step 2: Creating pre-holes: During the surgery, a drill bit is used to create pre-holes of appropriate diameter in the femoral neck and femoral head;

[0022] Step 3: Calculation of the expansion and compression distance: After the self-expanding compression screw is implanted into the femoral head in its unexpanded natural state, assuming the expansion portion is a straight line, the length of a single arm of the expandable support is R, the depth of the drive screw is △, the distance the center point moves backward relative to its original position during the expansion process is x, and the height h1 of the self-expanding compression screw expanded inside the pre-hole is equal to half the diameter h of the pre-hole. The depth △ can be calculated using the following formula:

[0023] (R-△+x) 2 +h1 2 =R 2

[0024] (Rx) 2 +h1 2 =R 2

[0025] After calculating the depth Δ of the drive screw, the expansion size of the expandable bracket can be precisely controlled according to the dial.

[0026] Step 4: Insert the self-expanding compression screw: After the hole has been enlarged, insert the self-expanding compression screw into the pre-hole using a special instrument;

[0027] Step 5: Angled bone plate implantation: Insert the mating segment of the angled bone plate onto the proximal segment of the self-expanding compression screw, so that the main body of the angled bone plate fits against the outer surface of the femur;

[0028] Step Six: Implantation of Self-Expanding Locking Screw: Align the self-expanding locking screw with the screw fitting and implant it into the femur;

[0029] Step 7: Expanding the self-expanding pressure screw: Use a worm gear to connect to the drive screw, then rotate the worm gear through the rotating end of the worm gear to drive the drive screw to rotate. Through the cooperation of the drive screw and the distal internal thread, the expandable bracket is gradually expanded to the predetermined size, and then the worm gear is removed; the predetermined size is read through the dial.

[0030] The beneficial effects of this invention are:

[0031] It effectively solves the problems of easy nail removal and weak anti-rotation effect of existing products. It can also use a visual and controllable self-expansion platform to precisely control the distance of expansion and pressure, so as to avoid excessive expansion and excessive pressure on the patient's medullary cavity, which would affect the patient's intramedullary blood supply.

[0032] It also overcomes the disadvantages of intramedullary nail surgery, such as complicated operation, multiple surgical incisions, complex supporting instruments, and static fixation. It has the advantages of simple operation, relatively small damage, no need for special equipment, and low manufacturing cost, and is suitable for widespread use. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the self-expanding pressure screw of the present invention in its natural state;

[0034] Figure 2 This is a schematic diagram of the self-expanding pressure screw of the present invention in its expanded state;

[0035] Figure 3 This is a schematic diagram of the self-expanding locking screw of the present invention in its natural state;

[0036] Figure 4 This is a schematic diagram of the self-expanding tension locking screw in its expanded state according to the present invention;

[0037] Figure 5 This is a schematic cross-sectional view of the self-expanding locking screw of the present invention.

[0038] Figure 6 This is a schematic diagram of the structure of the bone plate of the present invention;

[0039] Figure 7 This is a schematic diagram of the self-expanding angled bone plate system of the present invention;

[0040] Figure 8 This is a front view of the visible and controllable self-expanding platform structure of the present invention;

[0041] Figure 9 This is a cross-sectional view of the visible and controllable self-expanding platform structure of the present invention;

[0042] Figure 10 This is a partially enlarged view of the self-expansion process structure of the present invention;

[0043] Figure 11 This is a schematic diagram of the self-expansion implementation scheme of the present invention;

[0044] Figure 12 This is a schematic diagram of the structure of the self-expanding angled bone plate of the present invention after implantation;

[0045] In the diagram: 1. Angled bone plate; 11. Fitting section; 12. Plate body; 13. Screw fitting hole; 2. Self-expanding compression screw; 21. Proximal segment; 22. Expandable support; 221. Expandable connecting plate; 2211. Connecting plate; 23. Distal segment; 3. Self-expanding locking screw; 31. Screw body; 32. Opening support; 33. Screw inner core; 34. Drug release hole; 4. Visual and controllable self-expanding platform; 41. Worm gear; 42. Worm wheel; 43. Housing; 44. Worm wheel shaft; 45. Pointer; 46. Dial; 47. Limiting rod; 48. Bearing; 49. Key; 5. Drive screw. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0047] A self-expanding angled bone plate fixation system for femoral neck fractures includes: an angled bone plate 1, a self-expanding compression screw 2, a self-expanding locking screw 3, and a visually controllable self-expanding platform 4.

[0048] like Figure 12 As shown, the self-expanding compression screw 2 is inserted into pre-drilled holes in the femoral neck and femoral head during use. One end of the angled bone plate 1 is fixedly connected to the self-expanding compression screw 2. The self-expanding locking screw 3 is used to fix the angled bone plate 1 to the femur. The visual and controllable self-expanding platform 4 is used to control the expansion size of the self-expanding compression screw 2.

[0049] like Figure 6 and Figure 7 As shown, the angled bone plate 1 includes a mating section 11 and a plate body 12 that are fixedly connected. The mating section 11 has a hollow columnar structure, and the cross-section of the hollow part is not circular. The plate body 12 has a plate-like structure with a plurality of screw mating holes 13 evenly distributed on it to accommodate self-expanding locking screws 3. The hollow mating section 11 allows the self-expanding compression screw 2 to be inserted into the hollow part. Because the cross-sectional shape of the hollow part is not circular, the mating section 11 and the self-expanding compression screw 2 will not rotate relative to each other after insertion, avoiding rotation of the femoral head during surgery and recovery, and thus better promoting fracture healing. Preferably, the cross-sectional shape of the hollow part of the mating section 11 is waist-shaped with planes on both sides, and correspondingly, the cross-section of the self-expanding compression screw 2 is also waist-shaped with planes on both sides.

[0050] One end of the self-expanding compression screw 2 is adapted to be inserted into the mating section 11; the other end is inserted into the pre-hole of the femoral neck and is provided with an expandable part.

[0051] Specifically, such as Figure 1 and Figure 2As shown, the self-expanding pressure screw 2 includes a proximal section 21, an expandable bracket 22, and a distal section 23. The expandable bracket 22 is disposed between the proximal section 21 and the distal section 23. The proximal section 21 and the distal section 23 are hollow, forming an operating cavity. A distal internal thread is formed on the inner wall of the operating cavity of the distal section 22, and a proximal internal thread is formed on the inner wall of the operating cavity of the proximal section 21. A drive screw 5 is disposed inside the operating cavity. The two ends of the drive screw 5 are provided with opposite threads, which respectively connect to the proximal internal thread and the internal thread. The proximal section 21 can be fitted into the hollow portion inside the mating section 11 and tightly engages with it to prevent rotation.

[0052] The threads on the drive screw 5 corresponding to the proximal internal thread and the distal internal thread are in opposite directions. When the drive screw 5 rotates, the opposite threads cause the proximal section 21 and the distal section 23 to move in opposite or opposite directions, causing the expandable bracket 22 to expand or shrink.

[0053] Preferably, such as Figure 10 As shown, the expandable support 22 includes several expandable connecting plates 221 evenly distributed circumferentially along the self-expanding pressure screw 2. Each expandable connecting plate 221 includes two connecting plates 2211, which are bendably connected. The ends of the two connecting plates 2211 are respectively bendably connected to the proximal segment 21 and the distal segment 23. When the expandable support 22 expands, the two connecting plates 2211 bend together, and simultaneously, the connecting plates 2211 also bend between the proximal segment 21 and the distal segment 23.

[0054] The self-expanding locking screw 3 engages with the screw mating hole 13 to fix the angled bone plate 1 to the femur.

[0055] Preferably, such as Figures 3-5 As shown, the self-expanding locking screw 3 includes a screw body 31 and an opening bracket 32. The opening bracket 32 ​​is located at the end of the screw body 31 and is driven to expand by a screw core 33 located inside the screw body 31. The opening bracket 32 ​​is provided with a drug release hole 34. Specifically, a receiving groove is formed at the front end of the screw body 31, and the opening bracket 32 ​​is slidably disposed in this receiving groove, with one end abutting against the screw core 33. Rotating the screw core 33 pushes the opening bracket 32 ​​to move, causing it to expand forward and expose the drug release hole 34 to release medication. The self-expanding locking screw not only improves the fixation effect, but the drug release hole 34 can also release medications such as those promoting bone growth to improve the intra-articular environment, significantly improving the bone environment inside the humeral head and accelerating healing.

[0056] One end of the visual and controllable self-expanding platform 4 is connected to the self-expanding pressure screw 2, and a display mechanism is provided to display the expansion size of the self-expanding pressure screw 2.

[0057] Specifically, such as Figure 8 and Figure 9 As shown, the visible and controllable self-expanding platform 4 includes a worm gear 41, a worm wheel 42, and a housing 43. The worm gear 41 meshes with the worm wheel 42, and the meshing point is located inside the housing 43. Both ends of the worm gear 41 extend outside the housing 43; one end can extend into the operating cavity and connect to the drive screw 5, driving the drive screw 5 to rotate; the other end is used to control rotation. During operation, the worm gear 41 can be rotated by holding this end to drive the drive screw 5 to rotate. Preferably, the worm gear 41 is rotatably connected to the housing 43 via a bearing 48. The connection between the worm gear 41 and the drive screw 5 is a slot connection, i.e., a polygonal slot is formed at the end of the drive screw 5, and a corresponding pin is provided at the end of the worm gear 41 that can be inserted into the slot to connect the two and achieve torque transmission.

[0058] A worm gear shaft 44 is fixedly mounted at the center of the worm gear 42. A pointer 45 is fixedly mounted at the other end of the worm gear shaft 44, which is fixedly connected to the worm gear 42. A dial 46 is correspondingly mounted on the pointer 45. Specifically, the worm gear 42 and the worm gear shaft 44 are fixedly connected by a key 49, so that the pointer 45 rotates together with the worm gear 42. Preferably, both the pointer 45 and the dial 46 are located inside the housing 43, and transparent parts are provided at corresponding locations for observation and protection.

[0059] Furthermore, a limit rod 47 is provided on the housing 43; the limit rod 47 can lock the worm gear 42. Specifically, the limit rod 47 is rotatably connected to the housing 43 and can be screwed into the housing 43 to lock the worm gear 42 to prevent the pointer 45 from rotating.

[0060] More preferably, the dial 46 has a value from 1 to 80, with each interval representing 0.1 mm. The large transmission ratio of the worm gear 41 and worm wheel 42 amplifies minute displacements. Specifically, the transmission ratio of the worm gear 41 to the worm wheel 42 is 1:20. The distal expandable stent 22 of the intramedullary nail is expanded by the drive screw 5. After expansion, rotating the limiting rod 47 locks the entire visible and controllable self-expanding platform 2. At this point, the value is read from the dial as the depth to which the drive screw 5 is screwed in.

[0061] A method of using the above-mentioned self-expanding angled plate fixation system for femoral neck fractures includes the following steps:

[0062] Step 1: Preoperative preparation: Examine the length of the patient's femoral head and neck under CT or X-ray, and select an appropriate compression screw for surgery based on the length of the patient's femoral head and neck.

[0063] Step 2: Creating pre-holes: During the operation, a drill is used to create pre-holes of appropriate diameter in the femoral neck and femoral head; the pre-holes include the pre-holes corresponding to the self-expanding compression screw 2 and the self-expanding locking screw 3.

[0064] Step 3: Calculate the distance for applying pressure; for example... Figure 11 As shown, when the self-expanding compression screw 2 is implanted into the femoral head in its unexpanded natural state, assuming the expanded portion is a straight line, the length of a single arm of the expandable support 22 (in this embodiment, the length of the connecting plate 2211) is R, the depth of the drive screw 5 screwed in is Δ, the distance the center point moves backward relative to its original position during the expansion process is x, and the height h1 of the self-expanding compression screw 2 expanded inside the pre-hole is equal to half the diameter h of the pre-hole. The depth Δ of screwing in can be calculated using the following formula:

[0065] (R-△+x) 2 +h1 2 =R 2

[0066] (Rx) 2 +h1 2 =R 2

[0067] After calculating the depth △ of the drive screw 5, the expansion size of the expandable bracket 22 can be precisely controlled according to the dial 46;

[0068] For example, assuming the width of the patient's medullary cavity is 10mm, if a self-expanding intramedullary nail is used, the required expansion height is h1 = 5mm. Given that the expansion scaffold length of the self-expanding intramedullary nail is R = 15mm, Δ = 1.72mm can be calculated according to the above formula. At this point, the depth to which the drive screw 4 needs to be screwed into the self-expanding intramedullary nail 1 can be known before the operation. This screwing depth can be displayed on the dial 26 on the visual and controllable self-tensioning platform 2. This can avoid causing excessive stimulation to the patient's medullary cavity, thereby protecting the blood supply of the endosteal membrane.

[0069] Step 4: Insert self-expanding compression screw 2: After the hole is enlarged, insert the self-expanding compression screw 2 into the pre-hole using a special instrument;

[0070] Step 5: Implantation of angled bone plate 1: Insert the mating segment 11 of angled bone plate 1 into the proximal segment 21 of self-expanding compression screw 2, so that the plate body 12 of angled bone plate 1 fits against the outer surface of the femur.

[0071] Step Six: Implant Self-Expanding Locking Screw 3: Align the self-expanding locking screw 3 with the screw and insert it into the femur through the slot 13;

[0072] Step 7: Expand the self-expanding pressure screw 2: Connect the worm gear 41 to the drive screw 5, and then rotate the worm gear 41 through the rotating end of the worm gear 41 to drive the drive screw 5 to rotate. Through the cooperation of the drive screw 5 with the distal internal thread and the proximal internal thread, the expandable bracket 22 is gradually expanded until the predetermined size is reached. Then remove the worm gear 41. The predetermined size is read through the dial 46.

[0073] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A self-expanding angled bone plate fixation system for femoral neck fractures, characterized in that, include: Angle-type bone plate (1), self-expanding compression screw (2), self-expanding locking screw (3), visual and controllable self-expanding platform (4). The angled bone plate (1) includes a mating section (11) and a plate body (12) that are fixedly connected; the mating section (11) has a hollow columnar structure and the cross-section of the hollow part is not circular; the plate body (12) is provided with a plurality of screw mating holes (13) evenly. One end of the self-expanding compression screw (2) is adapted to be inserted into the mating section (11); the other end is inserted into the pre-hole of the femoral neck and is provided with an expandable part; The self-expanding locking screw (3) engages with the screw mating hole (13) to fix the angled bone plate (1). One end of the visible and controllable self-expanding platform (4) is connected to the self-expanding pressure screw (2), and a display mechanism is provided to display the expansion size of the self-expanding pressure screw (2); The self-expanding pressure screw (2) includes a proximal section (21), an expandable bracket (22), and a distal section (23); the expandable bracket (22) is disposed between the proximal section (21) and the distal section (23); the proximal section (21) and the distal section (23) are hollow to form an operating cavity, and a distal internal thread is formed on the inner wall of the operating cavity of the distal section (23), and a proximal internal thread is formed on the inner wall of the operating cavity of the proximal section (21); a drive screw (5) is disposed inside the operating cavity; the two ends of the drive screw (5) are provided with opposite threads that are respectively connected to the proximal internal thread and the distal internal thread; the proximal section (21) is adapted to be inserted into the mating section (11); The visible and controllable self-expanding platform (4) includes a worm (41), a worm wheel (42), and a housing (43); the worm (41) meshes with the worm wheel (42), and the meshing point is located inside the housing (43); both ends of the worm (41) extend outside the housing (43), one end is connected to the self-expanding pressure screw (2), and the other end is used to control rotation; a worm wheel shaft (44) is fixedly provided at the center of the worm wheel (42), and a pointer (45) is fixedly provided at the other end of the worm wheel shaft (44), and a scale (46) is provided corresponding to the pointer (45); A limit rod (47) is provided on the housing (43); the limit rod (47) can lock the worm gear (42). When the self-expanding compression screw (2) is implanted into the femoral head in its unexpanded natural state, assuming the expanded portion is a straight line, the single arm length of the expandable support (22) is R, the depth of the drive screw (5) screwed in is △, the distance the center point moves backward relative to its original position during the expansion process is x, and the height h1 of the self-expanding compression screw (2) being expanded inside the pre-hole is equal to half the diameter h of the pre-hole. The depth △ of screwing in can be calculated using the following formula: (R-△+x) 2 +h1 2 =R 2 (Rx) 2 +h1 2 =R 2 After calculating the depth Δ of the drive screw (5) screwing in, the expansion size of the expandable bracket (22) can be precisely controlled according to the dial (46).

2. The self-expanding angled bone plate fixation system for femoral neck fractures according to claim 1, characterized in that, The expandable support (22) includes several expandable connecting plates (221), each of which includes two connecting plates (2211). The two connecting plates (2211) are bendable and connected, and the ends of the two connecting plates (2211) are bendable and connected to the proximal segment (21) and the distal segment (23), respectively.

3. The self-expanding angled bone plate fixation system for femoral neck fractures according to claim 1, characterized in that, The self-expanding locking screw (3) includes a screw body (31) and an opening bracket (32); the opening bracket (32) is disposed at the end of the screw body (31) and is driven to expand by a screw core (33) disposed inside the screw body (31); the opening bracket (32) is provided with a drug release hole (34).

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