Internal fixation bone nail device capable of crossing fracture line

Abstract

The invention discloses an internal fixation bone nail device capable of crossing a fracture line. The internal fixation bone nail device comprises an expansion tube, an expansion core arranged in the expansion tube, a locking sleeve located behind the expansion tube and a fixing plate located behind the locking sleeve. An expansion part is arranged at the front end of the expansion tube; the expansion core comprises an expansion part for expanding the expansion part and a connecting rod part fixed at the rear end of the expansion part; the expansion core penetrates through the expansion pipe in a sliding manner; the rear end of the connecting rod part extends out of the expansion pipe and is in threaded connection with the front end of the locking sleeve; and the fixing plate is fixed at the rear end of the locking sleeve through a fixing bolt. The expansion part is occluded on a cortical bone on one side of a fracture part, and the fixing plate is used for pressurizing and fixing the cortical bone on the opposite side, so that the fracture part is firmly fixed by the two ends of the device, and the fracture part is prevented from shifting; according to the invention, the drilling requirement on the fracture part can be completed by only one drill bit, and two drill bits with different specifications do not need to be switched for drilling, so that the drilling operation is simplified, and the drilling failure rate is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of orthopedic auxiliary instruments, and in particular to an internal fixation bone screw device capable of crossing a fracture line. Background Art

[0002] Bone screws are non-active surgical metal implants for bone joining, commonly used in orthopedic internal fixation surgery, fixation of fracture ends, reduction or bone puncture and bone traction, etc. In the prior art, commonly used bone screws are mainly used for internal fixation with matching fixation plates or for compression fixation of fracture ends.

[0003] Specifically, for spiral fractures and butterfly fractures, lag screws are usually inserted to fix the fracture site. The steps for inserting the lag screw are as follows: cut the skin on one side of the patient's fracture site to form an incision; first use a larger drill bit to drill a hole in the cortical bone on that side through the incision; insert a sleeve to fix the direction; then use a smaller drill bit to pass through the above-mentioned drill hole and penetrate the cortical bone on the opposite side, thereby forming a drill hole across the fracture line; insert the lag screw. The lag screw needs to be perpendicular to the fracture line to achieve a better pressure effect.

[0004] Among them, since a larger drill bit is used to drill a hole in the cortical bone on one side, the inserted tension screw has no bite force on the cortical bone on that side, so the inserted tension screw is more likely to loosen. Once the inserted tension screw loosens, the tension screw cannot effectively pressurize the fracture site, which leads to poor stability of the tension screw fixing the fracture site and is prone to displacement again.

[0005] In addition, during the process of drilling the fracture site, it is necessary to switch between two drill bits of different specifications, which is complicated to operate and prone to failure, thus causing secondary injuries to the patient. Summary of the invention

[0006] The purpose of the present invention is to provide an internal fixation bone screw device that can cross the fracture line, so that only one drill bit is needed to meet the requirement of inserting the device into the fracture site. One end of the device bites into the cortical bone on one side through the expansion part, and the other end effectively pressurizes the cortical bone on the opposite side through the fixing plate, so that the two ends of the device can firmly fix the fracture site to prevent the fracture site from displacement.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] An internal fixation bone nail device capable of crossing a fracture line comprises an expansion tube, an expansion core placed in the expansion tube, a locking sleeve located behind the expansion tube, and a fixing plate located behind the locking sleeve;

[0009] An expansion part is provided at the front end of the expansion tube, and the expansion core includes an expansion part for expanding the expansion part and a connecting rod part fixed at the rear end of the expansion part; the expansion core is slidably penetrated through the expansion tube, and the rear end of the connecting rod part extends outside the expansion tube and is threadedly connected to the front end of the locking sleeve; the fixing plate is fixed to the rear end of the locking sleeve by fixing bolts.

[0010] The expansion part is engaged with the expansion part through cooperation with the expansion part, and the fixing plate is effectively pressurized on the opposite cortical bone through cooperation with the locking sleeve, so that the device can firmly fix the fracture site and prevent the fracture site from displacement.

[0011] The front and rear ends of the device are effectively fixed to the front and rear ends of the fracture site, thereby improving the stability of the device in fixing the fracture site.

[0012] As a further solution of the present invention, the expansion tube includes a fixed part and the expansion part; the center of the fixed part is provided with a first axial through hole for the connecting rod part to pass through, and its inner diameter is smaller than the outer diameter of the locking sleeve; the expansion part includes a plurality of expansion petals arranged along the circumference, and the rear end of the expansion petal is fixedly connected to the front end of the fixed part; the expansion part is a conical head, the small diameter end of the expansion part is located at the rear side and is connected to the connecting rod part, and the maximum outer diameter of the expansion part is larger than the inner diameter of the first axial through hole. The above structure is adopted so that the expansion part supports the expansion petal to expand outward, so as to achieve the purpose of stably fixing the device on the cortical bone.

[0013] As a further solution of the present invention, an axial gap is provided between two adjacent expansion petals, the axial gap extends backward to form a limiting groove, and a limiting protrusion is correspondingly provided on the outer peripheral wall of the expansion part; the limiting protrusion is fixed at the rear end of the expansion part and is located in the corresponding limiting groove. With the above structure, the forward and backward movement of the expansion core is guided.

[0014] As a further solution of the present invention, the outer surface of the expansion flap is provided with a plurality of protrusions for engagement. The above structure is adopted so that the expansion part is firmly engaged on the cortical bone.

[0015] As a further solution of the present invention, a threaded through hole is provided in the central axial direction of the locking sleeve, the front end of the threaded through hole is threadedly connected to the rear end of the connecting rod, and the rear end of the threaded through hole is threadedly connected to the fixing bolt. The above structure simplifies the structure of the locking sleeve.

[0016] As a further solution of the present invention, the fixing bolt is a countersunk bolt; the fixing plate is provided with a corresponding countersunk hole, the countersunk hole being composed of a tapered hole and a round hole connected to the tapered hole. The above solution is adopted to keep the surface of the fixing plate flat.

[0017] As a further solution of the present invention, the internal fixation bone screw device also includes an auxiliary sleeve, the center of which is provided with a second axial through hole for the locking sleeve to pass through, and the length of the auxiliary sleeve is greater than the length of the locking sleeve; the front end surface of the auxiliary sleeve is provided with a hexagonal bayonet, and the hexagonal bayonet is connected to the second axial through hole, and the rear end surface of the expansion tube is correspondingly provided with a hexagonal boss adapted to the hexagonal bayonet; the first axial through hole of the expansion tube is penetrated through the hexagonal boss. The above structure is adopted so that the auxiliary sleeve and the expansion tube can be plugged in.

[0018] As a further solution of the present invention, the rear end outer wall of the auxiliary sleeve is provided with an outer hexagonal structure. The above structure is adopted to facilitate the wrench to clamp.

[0019] As a further solution of the present invention, the rear end surface of the locking sleeve is provided with an inner hexagonal groove, and the threaded through hole of the locking sleeve is coaxially arranged with the inner hexagonal groove and is connected to each other. The above structure is adopted so that the locking sleeve can be twisted by a wrench.

[0020] As a further solution of the present invention, the material of the internal fixation bone screw device is medical stainless steel or medical titanium alloy. The above materials are used to effectively fix the fracture site.

[0021] Beneficial effects of the present invention:

[0022] The expansion part is engaged with the expansion part on one side of the cortical bone by cooperation with the expansion part, and the fixing plate is effectively pressed on the opposite side of the cortical bone by cooperation with the locking sleeve, so that the two ends of the device can firmly fix the fracture site to prevent the fracture site from shifting; compared with the original lag screw, the device strengthens the stability of the fracture site fixation;

[0023] Through the cooperation between the expansion flap and the expansion part, the device can effectively occlude the cortical bone;

[0024] The cooperation between the limiting groove and the limiting protrusion realizes the guidance of the forward and backward movement of the expansion core;

[0025] The difficulty of fixing the expansion pipe by the first wrench is reduced by providing an auxiliary casing;

[0026] The present invention requires only one drill bit to complete the drilling of the fracture site, without switching between two drill bits of different specifications for drilling, thus simplifying the drilling operation and reducing the drilling failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings:

[0028] Figure 1 It is a three-dimensional structural schematic diagram of the present invention;

[0029] Figure 2 is a cross-sectional view of the present invention;

[0030] Figure 3 is a schematic diagram of an expansion tube in the present invention;

[0031] Figure 4 is a cross-sectional view of the expansion core of the present invention;

[0032] Figure 5 is a schematic diagram of an expansion core in the present invention;

[0033] Figure 6 It is a partial schematic diagram of the expansion tube and the expansion core in the present invention;

[0034] Figure 7 It is a schematic diagram of the connection between the locking sleeve and the expansion core in the present invention;

[0035] Figure 8 It is a schematic diagram of the connection between the locking sleeve and the auxiliary sleeve in the present invention;

[0036] Fig. 9 It is a cross-sectional view of the connection between the locking sleeve and the auxiliary sleeve in the present invention;

[0037] Fig.10 is a schematic diagram of the present invention being inserted into a bone to be fixed;

[0038] Fig.11 is a schematic diagram of the expansion part of the present invention engaging with the cortical bone of the bone to be fixed;

[0039] Fig.12 is a schematic diagram of the expansion tube and the auxiliary casing after being separated in the present invention;

[0040] Fig.13 It is a schematic diagram of fixing a fixing plate according to the present invention.

[0041] The accompanying drawings are denoted as follows:

[0042] 1. Expansion tube; 11. Expansion flap; 111. First protrusion; 112. Second protrusion; 12. Small diameter section; 13. Conical transition section; 14. Large diameter section; 15. Hexagonal boss; 16. Limiting groove; 2. Expansion core; 21. Expansion section; 22. Connecting rod section; 23. Limiting protrusion; 3. Locking sleeve; 4. Fixing plate; 41. Countersunk hole; 5. Fixing bolt; 6. Auxiliary sleeve; 61. External hexagonal structure; 7. First wrench; 8. Second wrench; 9. Bone to be fixed; 91. Cortical bone. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] An internal fixation bone screw device that can cross the fracture line, which is made of medical stainless steel or medical titanium alloy. Figure 1 and Figure 2 As shown, the internal fixation bone nail device includes an expansion tube 1, an expansion core 2 placed in the expansion tube 1, a locking sleeve 3 located at the rear of the expansion tube 1, and a fixing plate 4 located at the rear of the locking sleeve 3. The expansion tube 1 includes an expansion portion and a fixing portion connected to each other. The expansion portion is located at the front end of the expansion tube 1. The expansion core 2 includes an expansion portion 21 for propping up the expansion portion and a connecting rod portion 22 fixed at the rear end of the expansion portion 21. The expansion core 2 is slidably inserted into the expansion tube 1, and the rear end of the connecting rod portion 22 extends to the outside of the expansion tube 1 and is threadedly connected to the front end of the locking sleeve 3. The fixing plate 4 is located at the rear of the locking sleeve 3, and the fixing plate 4 is fixed to the rear end of the locking sleeve 3 by a fixing bolt 5.

[0045] The internal fixation bone screw device can fix the fracture site of the patient across the fracture line. In this embodiment, the fracture site of the patient is the bone to be fixed 9. The bone to be fixed 9 includes cancellous bone and cortical bone 91 wrapped around the outside of the cancellous bone.

[0046] The expansion core 2 is placed in the expansion tube 1, and the expansion part 21 is placed in the expansion part. When the expansion part 21 does not expand the expansion part, the expansion part is in an unexpanded state; when the expansion part 21 expands the expansion part, the expansion part expands outwards and is in an expanded state.

[0047] See also Figure 3 and Figure 6 As shown, the expansion portion includes six expansion flaps 11 arranged along the circumference. The front end of the expansion flap 11 is a free end, and the rear end of the expansion flap 11 is fixedly connected to the front end of the fixed portion. The six expansion flaps 11 are arranged at intervals around the circumference to form a connecting cavity with an open front end. In order to make the expansion portion firmly bite on the cortical bone 91, the outer surface of the expansion flap 11 is provided with a plurality of protrusions for biting. Specifically, the outer edge of the front end of the expansion flap 11 extends radially outward with a first protrusion 111. When the expansion portion is in an expanded state, the first protrusion 111 can effectively bite on the cortical bone 91.

[0048] In addition, two second protrusions 112 are provided on the outer surface of each expansion flap 11. The two second protrusions 112 are both located behind the first protrusion 111, and the second protrusions 112 are spaced apart from the first protrusion 111. The two second protrusions 112 are spaced apart along the axial direction to increase the contact area between the expansion part and the bone 9 to be fixed. Specifically, when the expansion part is in the expanded state, the second protrusions 112 can effectively bite on the cancellous bone, thereby improving the stability of fixing the bone 9 to be fixed.

[0049] See also Figure 2 and Figure 3 As shown, the fixing part includes a small diameter section 12, a conical transition section 13 and a large diameter section 14 from front to back, and this structure facilitates the smooth insertion of the fixing part into the drilled hole of the bone 9 to be fixed. The small diameter section 12 is fixedly connected to the expansion part. A first axial through hole is provided in the center of the fixing part for the connecting rod part 22 to pass through. The rear end of the connecting cavity is connected to the front end of the first axial through hole. The inner diameter of the first axial through hole is smaller than the outer diameter of the locking sleeve 3, which acts as a limit to the locking sleeve 3 to prevent the locking sleeve 3 from being inserted into the first axial through hole.

[0050] See also Figure 4 and Figure 5 As shown, the expansion portion 21 is a conical head, and its cross section is circular. The small diameter end of the expansion portion 21 is located at the rear side and is connected to the connecting rod portion 22. The expansion portion 21 acts on the connecting cavity from front to back, so that the expansion petals 11 on the expansion portion are all expanded outward, so as to achieve the purpose of stably fixing the device on the cortical bone 91. The maximum outer diameter of the expansion portion 21 is larger than the inner diameter of the first axial through hole, thereby limiting the expansion portion 21 to prevent the expansion portion 21 from being completely placed in the first axial through hole when moving backward.

[0051] See also Figure 4 As shown, the connecting rod portion 22 is divided into a smooth section and a threaded section from front to back. The outer diameter of the smooth section is equal to the outer diameter of the small diameter end of the expansion portion 21. The rear end of the threaded section extends outside the expansion tube 1 and is threadedly connected to the locking sleeve 3.

[0052] In order to ensure that the expansion core 2 only slides forward and backward in the expansion tube 1, and there is no relative rotation between the two, please refer to Figure 5 and Figure 6 As shown, the expansion tube 1 is provided with a limiting groove 16. Specifically, an axial gap is provided between two adjacent expansion petals 11, and the axial gap extends backward to form the limiting groove 16. A limiting protrusion 23 is correspondingly provided on the outer peripheral wall of the expansion part 21. The limiting protrusion 23 is fixed at the rear end of the expansion part 21. The limiting protrusion 23 is located in the corresponding limiting groove 16. The limiting groove 16 guides the forward and backward movement of the expansion core 2.

[0053] See also Figure 2As shown, a threaded through hole is provided in the central axial direction of the locking sleeve 3. The front end of the threaded through hole is threadedly connected to the rear end of the connecting rod portion 22, and the rear end of the threaded through hole is threadedly connected to the fixing bolt 5.

[0054] See also Figure 2 As shown, the fixing bolt 5 is a countersunk bolt so that the surface of the fixing plate 4 remains flat, that is, the head of the fixing bolt 5 does not protrude from the rear end surface of the fixing plate 4. Specifically, the fixing bolt 5 includes a threaded rod and a conical head fixed to the rear end of the threaded rod. A countersunk hole 41 is correspondingly provided on the fixing plate 4. The countersunk hole 41 consists of a conical hole and a circular hole connected to the conical hole. The threaded rod passes through the conical hole and the circular hole in sequence, and then is threadedly connected to the rear end of the locking sleeve 3. The conical head is placed in the conical hole.

[0055] A tightening groove is provided on the conical head of the fixing bolt 5. The tightening groove includes but is not limited to a straight shape, a cross shape, a hexagonal shape, a plum blossom shape, a pentagonal shape, etc. Preferably, the tightening groove of the fixing bolt 5 is a hexagonal shape, that is, the fixing bolt 5 can be tightened by a hexagonal wrench.

[0056] See also Figure 8 and Fig. 9 As shown, the internal fixation bone screw device also includes an auxiliary sleeve 6. A second axial through hole for the locking sleeve 3 to pass through is provided at the center of the auxiliary sleeve 6. The length of the auxiliary sleeve 6 is greater than the length of the locking sleeve 3. A hexagonal bayonet is provided on the front end surface of the auxiliary sleeve 6, and the hexagonal bayonet is connected to the second axial through hole. A hexagonal boss 15 adapted to the hexagonal bayonet is correspondingly provided on the rear end surface of the large diameter section 14. The first axial through hole of the expansion tube 1 is penetrated by the hexagonal boss 15.

[0057] When the hexagonal bayonet is plugged into the hexagonal boss 15, the auxiliary sleeve 6 is covered on the outside of the locking sleeve 3, and the locking sleeve 3 is completely located in the second axial through hole of the auxiliary sleeve 6. At this time, the outer wall of the auxiliary sleeve 6 is flush with the outer wall of the expansion tube 1, so that the auxiliary sleeve 6 and the expansion tube 1 can be smoothly inserted into the drilled hole of the bone 9 to be fixed. After the auxiliary sleeve 6 and the expansion tube 1 are inserted into the drilled hole, the rear end of the auxiliary sleeve 6 is exposed to the bone 9 to be fixed, so that the first wrench 7 clamps the rear end of the auxiliary sleeve 6, and the second wrench 8 extends into the second axial through hole to screw the locking sleeve 3.

[0058] Preferably, the first wrench 7 is an open-end wrench for easy removal. Fig. 9 and Fig.11 As shown, the rear end outer wall of the auxiliary sleeve 6 is provided with a corresponding outer hexagonal structure 61. When the auxiliary sleeve 6 and the expansion tube 1 are inserted into the drilled hole, the outer hexagonal structure 61 is exposed to the bone 9 to be fixed. The first wrench 7 fixes the auxiliary sleeve 6 by clamping the outer hexagonal structure 61, and then fixes the expansion tube 1 inserted in the hexagonal bayonet to prevent the expansion tube 1 from rotating.

[0059] Preferably, the second wrench 8 is a hexagonal wrench. Fig.10 and Fig.11 As shown, a corresponding hexagonal groove is formed on the rear end surface of the locking sleeve 3. The second wrench 8 is inserted into the hexagonal groove to twist the locking sleeve 3, thereby rotating the locking sleeve 3. The threaded through hole of the locking sleeve 3 is coaxially arranged with the hexagonal groove and communicated with each other. In addition, in order to allow the fixing bolt 5 to smoothly pass through the hexagonal groove and connect with the threaded through hole, the inner diameter of the hexagonal groove is larger than the inner diameter of the threaded through hole.

[0060] The above-mentioned internal fixation bone screw device is suitable for orthopedic internal fixation surgery on unilateral wound surface. The steps of the surgery are: cut the unilateral skin outside the bone 9 to be fixed (i.e. the fracture site) to form an incision; drill the bone 9 to be fixed through the incision, and the drill hole crosses the fracture line and penetrates the cortical bone 91 on the front and back sides of the bone 9 to be fixed; the internal fixation bone screw device is inserted into the inside of the bone 9 to be fixed through the drill hole and penetrates to the opposite bone surface, and the front and back ends of the internal fixation bone screw device are respectively fixed on the cortical bone 91 on the front and back sides of the bone 9 to be fixed, so as to reposition the bone 9 to be fixed; suture the incision.

[0061] Compared with the prior art, the internal fixation bone screw device only needs one drill bit to drill holes on the bone 9 to be fixed, without switching two drill bits of different specifications for drilling, thus simplifying the drilling operation and reducing the drilling failure rate.

[0062] The specific surgical method using the internal fixation bone screw device is:

[0063] S1, insert the rear end of the expansion core 2 into the expansion tube 1, so that the front and rear ends of the expansion core 2 are exposed outside the expansion tube 1, and then the rear end of the expansion core 2 is threadedly connected to the locking sleeve 3. At this time, the expansion part is in an unexpanded state. Figure 7 Then the auxiliary casing 6 is connected to the expansion pipe 1 as a whole, as shown in FIG. Figure 8 As shown;

[0064] S2, cutting the skin on one side of the patient near the bone 9 to be fixed, and then drilling the bone 9 to be fixed from that side, so that the drill hole crosses the fracture line and passes through both sides of the bone 9 to be fixed;

[0065] S3. Please refer to Fig.10 As shown, the front end of the component assembled in S1 is inserted into the drill hole, and the expansion portion of the expansion tube 1 first passes through the cortical bone 91 on one side of the bone 9 to be fixed through the drill hole, and then is placed in the cortical bone 91 on the other side of the bone 9 to be fixed, and at the same time, the rear end of the auxiliary sleeve 6 is exposed to the bone 9 to be fixed;

[0066] S4. Please refer to Fig.11As shown, one hand holds the first wrench 7 and fixes the expansion tube 1 by the first wrench 7; the other hand rotates the second wrench 8 and rotates the locking sleeve 3 by the second wrench 8, and the locking sleeve 3 drives the expansion core 2 to slide backward, so that the expansion petals 11 on the expansion part are all expanded outward, that is, the expansion part in the expanded state is stably fixed on the cortical bone 91 on the front side of the bone 9 to be fixed; wherein, during the rotation of the locking sleeve 3, since the expansion core 2 is limited by the guiding effect of the limit groove 16, it only moves forward and backward, and therefore does not rotate relative to the expansion tube 1.

[0067] S5, remove the first wrench 7 and the second wrench 8; pull the auxiliary sleeve 6 off the expansion tube 1, and remove the auxiliary sleeve 6 from the drill hole of the bone 9 to be fixed. Fig.12 As shown, only the expansion tube 1, the expansion core 2 and the locking sleeve 3 are fixed in the borehole;

[0068] S6. Please refer to Fig.13 As shown, the fixing plate 4 is placed behind the drill hole and fits on the outer surface of the bone 9 to be fixed, and the fixing plate 4 is fixed to the locking sleeve 3 by tightening the fixing bolt 5, that is, a pressurization effect is formed between the fracture fragments; wherein, since the expansion part is stably fixed on the cortical bone 91, the expansion part is limited by the cortical bone 91 and is in a static state. At the same time, the expansion core 2 is limited by the expansion part and cannot move, so that the expansion core 2 is also in a static state, and then the locking sleeve 3 threadedly locked with the expansion core 2 is also in a static state accordingly. Therefore, in the process of tightening the fixing bolt 5, the expansion tube 1, the expansion core 2 and the locking sleeve 3 are all in a static state and will not be affected by the rotation of the fixing bolt 5. Therefore, at this time, the expansion tube 1, the expansion core 2 and the locking sleeve 3 can be regarded as one, that is, the internal fixation bone nail device is connected between the fixing plate 4 and the expansion part to achieve a pressurization effect between the fracture fragments, thereby achieving effective fixation of the bone 9 to be fixed.

[0069] S7. Suture the incised wound.

[0070] The present invention achieves effective engagement of the device with the cortical bone 91 by cooperating between the expansion part and the expansion part 21, and enables the fixing plate 4 to effectively pressurize the opposite cortical bone 91 by cooperating between the fixing plate 4 and the locking sleeve 3, thereby enabling the two ends of the device to firmly fix the fracture site to prevent displacement of the fracture site; effective engagement of the device with the cortical bone 91 is achieved by cooperating between the expansion flap 11 and the expansion part 21; guidance of the forward and backward movement of the expansion core 2 is achieved by cooperating between the limiting groove 16 and the limiting protrusion 23; and the difficulty of fixing the expansion tube 1 by the first wrench 7 is reduced by the auxiliary sleeve 6.

[0071] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of patent protection of the present invention.

Claims

1. An internal fixation bone screw device capable of crossing a fracture line, characterized in that: It comprises an expansion pipe (1), an expansion core (2) disposed in the expansion pipe (1), a locking sleeve (3) located behind the expansion pipe (1), and a fixing plate (4) located behind the locking sleeve (3); The expansion tube (1) is provided with an expansion portion at the front end, and the expansion core (2) comprises an expansion portion (21) for expanding the expansion portion and a connecting rod portion (22) fixed to the rear end of the expansion portion (21); the expansion core (2) is slidably inserted into the expansion tube (1), and the rear end of the connecting rod portion (22) extends outside the expansion tube (1) and is threadedly connected to the front end of the locking sleeve (3); the fixing plate (4) is fixed to the rear end of the locking sleeve (3) by fixing bolts (5).

2. The internal fixation bone screw device according to claim 1, characterized in that: The expansion tube (1) comprises a fixed portion and an expansion portion; a first axial through hole for the connecting rod portion (22) to pass through is provided at the center of the fixed portion, and the inner diameter of the first axial through hole is smaller than the outer diameter of the locking sleeve (3); the expansion portion comprises a plurality of expansion petals (11) arranged along the circumference, and the rear end of the expansion petals (11) is fixedly connected to the front end of the fixed portion; the expansion portion (21) is a conical head, the small diameter end of the expansion portion (21) is located at the rear side and is connected to the connecting rod portion (22), and the maximum outer diameter of the expansion portion (21) is larger than the inner diameter of the first axial through hole.

3. The internal fixation bone screw device according to claim 2, characterized in that: An axial gap is provided between two adjacent expansion flaps (11), and the axial gap extends rearward to form a limiting groove (16). A limiting protrusion (23) is correspondingly provided on the outer peripheral wall of the expansion portion (21); the limiting protrusion (23) is fixed at the rear end of the expansion portion (21) and is located in the corresponding limiting groove (16).

4. The internal fixation bone screw device according to claim 2, characterized in that: The outer surface of the expansion flap (11) is provided with a plurality of protrusions for biting.

5. The internal fixation bone screw device according to claim 1, characterized in that: The locking sleeve (3) has a threaded through hole axially disposed in the center thereof, the front end of the threaded through hole being threadedly connected to the rear end of the connecting rod portion (22), and the rear end of the threaded through hole being threadedly connected to the fixing bolt (5).

6. The internal fixation bone screw device according to claim 1, characterized in that: The fixing bolt (5) is a countersunk bolt; a countersunk hole (41) is correspondingly opened on the fixing plate (4), and the countersunk hole (41) consists of a tapered hole and a circular hole connected to the tapered hole.

7. The internal fixation bone screw device according to claim 1, characterized in that: It also includes an auxiliary sleeve (6), the center of which is provided with a second axial through hole for the locking sleeve (3) to pass through, and the length of the auxiliary sleeve (6) is greater than the length of the locking sleeve (3); the front end surface of the auxiliary sleeve (6) is provided with a hexagonal bayonet, and the hexagonal bayonet is connected to the second axial through hole; the rear end surface of the expansion tube (1) is correspondingly provided with a hexagonal boss (15) adapted to the hexagonal bayonet, and the first axial through hole of the expansion tube (1) is penetrated by the hexagonal boss (15).

8. The internal fixation bone screw device according to claim 7, characterized in that: The rear end outer wall of the auxiliary sleeve (6) is provided with an outer hexagonal structure (61).

9. The internal fixation bone screw device according to claim 1, characterized in that: The rear end surface of the locking sleeve (3) is provided with an inner hexagonal groove, and the threaded through hole of the locking sleeve (3) is coaxially arranged with the inner hexagonal groove and is in communication with each other.

10. The internal fixation bone screw device according to claim 1, characterized in that: Its material is medical stainless steel or medical titanium alloy.

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