Length-adjustable spinal internal fixing device

Abstract

The invention discloses a length-adjustable spinal internal fixing device, and particularly relates to the field of medical instruments. Comprising a connecting pipe; the two connecting pieces are connected to the two sides of the connecting pipe in a sliding mode respectively; the two positioning sleeves are respectively connected to the free ends of the corresponding connecting pieces in a sliding manner; the two flexible casing pipes are arranged in the corresponding positioning sleeves respectively, the inner diameter of the flexible casing pipes is the same as that of the openings in the positioning sleeves, and the flexible casing pipes are connected with the corresponding connecting pieces in a sliding and sealing mode; the two positioning rings are connected to the outer walls of the corresponding positioning sleeves in a sliding mode, and each positioning ring is provided with a limiting hole; the two bone nails are arranged in the limiting holes of the corresponding positioning rings in a penetrating manner; and the driving piece can drive the two connecting pieces to move towards the interior of the positioning sleeve. By the adoption of the technical scheme, the problem that the length of an existing spine internal fixing device cannot be adjusted is solved, and self-adaptive adjustment of the length can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a length-adjustable spinal internal fixation device. BACKGROUND

[0002] In the field of spinal surgery, spinal internal fixation system has undergone significant changes from the early Harrington instrument to the modern three-dimensional orthopedic system based on pedicle screw. Pedicle screw rod internal fixation is usually composed of pedicle screw, longitudinal connecting rod or transverse connector. The screw is implanted into the vertebral body through the bony channel, and the connecting rod is locked with the screw head after pre-bending to form a rigid fixed structure. Once the internal fixation is installed, the overall length is fixed, which can provide mechanical stability to the spinal segment, promote bone fusion and restore anatomical sequence, and is an indispensable core instrument for the treatment of various spinal diseases.

[0003] However, this rigid fixed structure has obvious limitations. Because the spinal biomechanical environment has dynamic stability characteristics, the geometric relationship of the fixed segment may change after surgery due to the following factors: (1) absorption or subsidence of the intervertebral bone graft, causing the intervertebral space height to decrease; (2) screw loosening or displacement caused by micro-motion of the bone-screw interface in osteoporotic patients; (3) adaptive remodeling of the instrument-bone interface caused by stress redistribution under physiological load of the spine; (4) lateral bending orthopedics or physiological spinal growth in children. At this time, the spinal internal fixation device cannot adapt to the above changes to adjust the length, which will cause the internal plant to bear abnormal stress, showing mechanical complications such as screw stress concentration, broken nails, broken rods, etc., or delayed healing or even pseudoarthrosis formation of the bone fusion / healing interface due to stress shielding effect.

[0004] In summary, the existing spinal nail rod system is difficult to adapt to the dynamic changes of the postoperative spinal biomechanical environment due to the fixed length, resulting in a high incidence of mechanical complications. There is an urgent need for a new internal fixation device that can achieve postoperative self-regulation or controlled length adjustment. SUMMARY

[0005] The present application aims to provide a length-adjustable spinal internal fixation device, which solves the problem that the length of the existing spinal internal fixation device cannot be adjusted.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows: a length-adjustable spinal internal fixation device, comprising:

[0007] a connecting tube;

[0008] two connecting pieces, the two connecting pieces are respectively connected to the two sides of the connecting tube in a sliding manner;

[0009] two positioning sleeves, the two positioning sleeves are respectively connected to the free ends of the corresponding connecting pieces in a sliding manner;

[0010] Two flexible sleeves, two said flexible sleeves are arranged in the corresponding positioning sleeve respectively, two ends of the flexible sleeve are connected between the left and right two inner walls of the positioning sleeve, the inner diameter of the flexible sleeve is the same as the inner diameter of the opening of the positioning sleeve, the flexible sleeve is in sliding sealing connection with the corresponding connecting piece;

[0011] Two positioning rings, each said positioning ring is in sliding connection on the outer wall of the corresponding positioning sleeve, a through hole is formed in the top of each said positioning ring, a limiting hole is formed in the bottom of each said positioning ring;

[0012] Two bone nails, each said bone nail is arranged in the limiting hole of the corresponding positioning ring.

[0013] Further, the internal fixation device further comprises a driving member, the driving member is arranged in the connecting pipe, and the driving member can drive the two connecting pieces to move into the positioning sleeve respectively.

[0014] Through the above setting, the connecting pipe can be moved to the predetermined position by the driving member, which is helpful to improve the positioning accuracy of the connecting pipe.

[0015] Further, a sliding groove is formed in the side wall of the flexible sleeve, and a limiting rod is arranged on the connecting piece and in sliding connection in the sliding groove.

[0016] Through the above setting, the stability of the connecting piece can be kept by the limiting rod.

[0017] Further, the limiting hole is a stepped hole or a conical hole.

[0018] Through the above setting, the end of the bone nail can be supported by the limiting hole, so that the bone nail can be quickly installed and positioned, and the effective positioning of the bone nail can be realized in cooperation with the positioning sleeve, so as to ensure the fixing effect of the device.

[0019] Further, the positioning sleeve is provided with an annular groove in communication with the inside, the annular groove is arranged close to one side of the stop ring, a ventilation hole in communication with the inside of the positioning sleeve is formed in the annular groove, an air cushion flush with the outer surface of the positioning sleeve is arranged at the edge of the annular groove, the width of the air cushion is smaller than the width of the positioning ring, and the thickness of the air cushion is smaller than the depth of the annular groove.

[0020] Further, the positioning sleeve is provided with a stop ring, the stop ring is located on one side of the limiting hole and close to the limiting hole.

[0021] Through the above arrangement, the positioning ring can be accurately positioned by the blocking ring, the limiting hole can be located inside the air cushion, and the air in the positioning sleeve can be expanded into the limiting hole to further resist and limit the bone pin under the condition that the air flows, so that the reliability of the scheme is improved.

[0022] Further, the driving member includes a first magnet and two second magnets, the first magnet is arranged at the middle of the connecting pipe, and the two second magnets are respectively embedded at the ends of the connecting member, and the two second magnets generate repulsion with the first magnet, and under the premise of no other force, the repulsion generated by the first magnet and the second magnet can drive the connecting member to move to the middle of the positioning sleeve.

[0023] Through the above arrangement, the connecting member can be driven to move by the repulsion between the magnets, so as to change the pressure of the air in the positioning sleeve, so as to maintain the stability of the positioning of the positioning sleeve, the positioning ring and the bone pin, and the repulsion between the magnets can be dynamically adjusted according to the biomechanical environment of the patient's spine, thereby enhancing the flexibility and stability of the fixation of the scheme.

[0024] Further, the driving member is a bidirectional electric push rod, and the two push rods of the bidirectional electric push rod respectively abut against the ends of the two connecting members.

[0025] Through the above arrangement, the bidirectional electric push rod can be used to drive the two connecting members to move to the predetermined position.

[0026] Further, the inner wall of each positioning sleeve is embedded with a pressure sensor, and the pressure sensor is electrically connected with the bidirectional electric push rod.

[0027] Through the above arrangement, the pressure value in the positioning sleeve is monitored in real time by the pressure sensor, so that the initial value of the connecting member entering the positioning sleeve is adjusted by the pressure value, and the two connecting members are dynamically adjusted according to the biomechanical environment of the patient's spine.

[0028] Further, the end of each positioning sleeve is provided with an air inlet hole, and a one-way valve is installed in the air inlet hole.

[0029] Through the above arrangement, in order to improve the positioning and fixing effect of the bone pin, a small amount of gas can be filled in the positioning sleeve through the air inlet hole and the one-way valve to maintain a small positive pressure environment inside the positioning sleeve, so that the resistance of the air cushion to the bone pin can be improved when the connecting member moves, and the stability of the bone pin is further improved.

[0030] Compared with the prior art, the beneficial effects of the scheme are:

[0031] 1. The length-adjustable spinal internal fixation device provided in the scheme is capable of changing the stability of the connection between the positioning sleeve and the positioning ring and the relative position of the connecting member by driving the connecting member to push the air in the positioning sleeve to move and change the pressure in the positioning sleeve.

[0032] 2. The device has simple structure and convenient fixation and positioning operation of the bone nail, and is convenient for clinical popularization and application.

[0033] 3. The scheme also solves the problem that the length between the two bone nails of the fixed segment cannot be changed when the children in the physiological growth period or the patients with spinal scoliosis receive the concave side distraction technique, and the internal fixation device can actively adapt to the change of the patient's spine, which is beneficial to improve the treatment effect and also expands the application range of the scheme. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is an axonometric view of the length-adjustable spinal internal fixation device of Example 1;

[0035] Figure 2 is a top view of the length-adjustable spinal internal fixation device of Example 1;

[0036] Figure 3 is Figure 2 a sectional view of A-A in FIG. 1;

[0037] Figure 4 is Figure 2 a local enlarged view of B in FIG. 1;

[0038] Figure 5 is Figure 2 a sectional view of C-C in FIG. 1;

[0039] Figure 6 is a structural schematic view of the positioning ring in Example 1;

[0040] Figure 7 is a structural schematic view of the connecting rod in Example 1;

[0041] Figure 8 is a structural schematic view of the flexible sleeve of Example 1;

[0042] Figure 9 is a structural schematic view of the positioning sleeve of Example 1;

[0043] Figure 10is an axonometric view of a length-adjustable spinal internal fixation device of Example 2;

[0044] Figure 11 is a top view of a length-adjustable spinal internal fixation device of Example 2;

[0045] Figure 12 is Figure 11 is a sectional view of D-D in FIG. 1;

[0046] Figure 13 is a sectional view of a length-adjustable spinal internal fixation device of Example 5.

[0047] The reference signs in the drawings of the specification include: connecting tube 1, connecting piece 2, positioning sleeve 3, stop ring 4, air cushion 5, annular groove 6, air hole 7, flexible sleeve 8, sliding groove 9, limiting rod 10, positioning ring 11, limiting hole 12, bone screw 13, bidirectional electric push rod 14, pressure sensor 15, one-way valve 16, first magnet 17, second magnet 18. DETAILED DESCRIPTION

[0048] The application will be further described in detail through specific embodiments:

[0049] Example 1

[0050] As shown in FIG. 1, a length-adjustable spinal internal fixation device comprises: Figures 1 to 9

[0051] Connecting tube 1, both left and right ends of connecting tube 1 are provided with openings.

[0052] Two connecting pieces 2, the two connecting pieces 2 are respectively slidably connected at the openings on the left and right sides of connecting tube 1, and one end of connecting piece 2 is located outside connecting tube 1. In the process of fixing the device, connecting piece 2 will not slide out of connecting tube 1 to cause separation of the two.

[0053] Two positioning sleeves 3, the two positioning sleeves 3 are respectively slidably connected at the free ends of the corresponding connecting pieces 2. The outer surface of positioning sleeve 3 is adhered with a stop ring 4, which is arranged on the side close to air cushion 5. The position of positioning ring 11 can be determined by means of stop ring 4, so as to ensure that limiting hole 12 is located in the area corresponding to air cushion 5. Positioning sleeve 3 is provided with an annular groove 6 in communication with the inside. The annular groove 6 is arranged close to one side of stop ring 4. The annular groove 6 is provided with an air hole 7 in communication with the inside of positioning sleeve 3. The edge of annular groove 6 is provided with an air cushion 5 flush with the outer surface of positioning sleeve 3. The width of air cushion 5 is smaller than the width of positioning ring 11, and the thickness of air cushion 5 is smaller than the depth of annular groove 6, so that air cushion 5 is more likely to deform under the change of pressure in positioning sleeve 3 to realize the resistance and compression of bone screw 13 in limiting hole 12. ​

[0054] Two flexible sleeves 8 are respectively arranged in the corresponding positioning sleeves 3, one end of the flexible sleeve 8 is connected to the inner wall at the opening of the positioning sleeve 3, and the other end is connected to the inner wall opposite to the opening of the positioning sleeve 3. The inner diameter of the flexible sleeve 8 is the same as the inner diameter of the opening of the positioning sleeve 3, and the flexible sleeve 8 is in sliding sealing connection with the corresponding connecting piece 2. In the embodiment, a sliding groove 9 penetrating the side wall is formed at the top of each flexible sleeve 8, and a limiting rod 10 integrally formed in the sliding groove 9 is arranged at one end of the connecting piece 2 in the flexible sleeve 8, and the stability of the movement of the connecting piece 2 can be maintained by means of the limiting rod 10.

[0055] In the embodiment, all the retaining rings 4, the positioning sleeves 3, the connecting pieces 2 and the connecting pipes 1 are made of titanium alloy material, and if the two connecting pieces 2 are not in a straight line, the connecting pieces 2 can be pre-bent to meet the connection requirements. The air cushions 5 and the flexible sleeves 8 are made of flexible material, and the air cushions 5 and the flexible sleeves 8 can be driven by air pressure to position the bone nails 13 and the connecting pieces 2.

[0056] Two positioning rings 11 are respectively arranged in sliding connection with the outer wall of the corresponding positioning sleeve 3, and the upper side of each positioning ring 11 is a circular ring with an opening, and the lower side is a square structure integrally formed with the opening of the circular ring. In the embodiment, a limiting hole 12 is formed in the square structure of the positioning ring 11, the limiting hole 12 is a conical hole, and the inner wall of the positioning ring 11 and the outer wall of the positioning sleeve 3 are in clearance fit.

[0057] Two bone nails 13 are arranged in the limiting hole 12 of the corresponding positioning ring 11, and the installation of the bone nail 13 is facilitated by means of the limiting hole 12.

[0058] A driving piece is arranged in the connecting pipe 1, and the driving piece can drive the two connecting pieces 2 to move into the positioning sleeve 3. In the embodiment, the driving piece is a bidirectional electric push rod 14, and the bidirectional electric push rod 14 is fixedly arranged in the middle part of the connecting pipe 1. The two push rods of the bidirectional electric push rod 14 respectively abut against the end parts of the two connecting pieces 2. At the same time, a pressure sensor 15 is embedded in the inner wall of each positioning sleeve 3 away from the opening, and the pressure sensor 15 is electrically connected with the bidirectional electric push rod 14, and the distance of the movement of the connecting piece 2 driven by the bidirectional electric push rod 14 can be controlled by the pressure sensor 15.

[0059] The use method of the device is as follows:

[0060] S1, two bone nails 13 are respectively arranged through the opening and the limiting hole 12 of the corresponding positioning ring 11, and the two bone nails 13 are respectively fixed at the predetermined positions of the spine of the patient.

[0061] S2, one positioning sleeve 3 is inserted into the inside of any positioning ring 11, and the corresponding connecting piece 2 is moved by the bidirectional electric push rod 14, at this time the connecting piece 2 pushes the air in the flexible sleeve 8 into the space between the flexible sleeve 8 and the positioning sleeve 3, so that the pressure in the space increases to promote the air cushion 5 to expand outward, and the gap between the positioning sleeve 3 and the positioning ring 11 is blocked by the expansion of the air cushion 5, so that the relative position of the positioning sleeve 3 and the positioning ring 11 is kept unchanged, and the reliability of the positioning of the bone nail 13 is improved. At the same time, due to the increase of the pressure in the space, the flexible sleeve 8 will cover the connecting piece 2 more tightly, realizing the clamping and limiting of the connecting piece 2.

[0062] When the pressure sensor 15 in the positioning sleeve 3 detects a predetermined pressure value, the pressure sensor 15 controls the bidirectional electric push rod 14 to reset the piston rod on the side, so as to separate from the corresponding connecting piece 2.

[0063] S3, another positioning sleeve 3 is connected with the corresponding positioning ring 11 in the same way as step S2, and after the two positioning rings 11 and the positioning sleeve 3 are positioned, the bidirectional electric push rod 14 does not contact the two connecting pieces 2, and only the flexible sleeve 8 is used to clamp the connecting pieces 2.

[0064] S4, since the connecting piece 2 is not completely fixed and limited, as the biomechanical environment of the patient's spine changes, the two connecting pieces 2 can be driven by the two bone nails 13, the positioning rings 11 and the positioning sleeve 3 to adjust the overall length, so as to realize self-adaptive dynamic adjustment and enhance the function and fixing effect of the device. If the length of the two connecting pieces 2 changes, the pressure sensor 15 detects a smaller pressure value, and the pressure sensor 15 can be used to control the corresponding push rod of the bidirectional electric push rod 14 to push the corresponding connecting piece 2 to move, so as to maintain the internal pressure of the positioning sleeve 3.

[0065] In this embodiment, when the two bone nails 13 move or misalign, the self-adaptive change of the two connecting pieces 2 can meet the small movement demand through the internal fixation device, avoiding the risk of fracture of the two bone nails 13 due to the inability to meet the movement demand.

[0066] Embodiment 2

[0067] As shown in Figures 10-12 The difference between this embodiment and embodiment 1 is that in this embodiment, the end of each positioning sleeve 3 is provided with an air inlet hole, and a one-way valve 16 is installed in the air inlet hole.

[0068] The difference between the usage method of this embodiment and the usage method of embodiment 1 is only that: in order to improve the clamping and resisting effect of the flexible sleeve 8 and the air cushion 5, a certain amount of air can be injected into the interior of the positioning sleeve 3 through the air inlet and the one-way valve 16 before using this device for fixation, so as to keep the interior of the positioning sleeve 3 under a slight positive pressure. At this time, by moving the connector 2 into the flexible sleeve 8, the air pressure inside the positioning sleeve 3 is increased, thereby using the air pressure to enhance the clamping force on the connector 2, as well as the resisting effect of the air cushion 5 on the bone nail 13 after expansion.

[0069] This embodiment can increase the internal pressure of the positioning sleeve 3, thereby reducing the size of the positioning sleeve 3 while maintaining the positive pressure required for clamping and positioning.

[0070] Example 3

[0071] The only difference between this embodiment and Embodiment 1 is that in this embodiment, the limiting hole 12 is a stepped hole.

[0072] Example 4

[0073] like Figure 9 As shown, the only difference between this embodiment and embodiment 2 is that the driving component is different and the pressure sensor 15 is not provided.

[0074] The driving component in this embodiment includes a first magnet 17 and two second magnets 18. The first magnet 17 is disposed in the middle of the connecting tube 1, and the two second magnets 18 are respectively embedded in the ends of the connector 2. Both second magnets 18 generate a repulsive force with the first magnet 17. Under the premise of no other force, the repulsive force generated by the first magnet 17 and the second magnet 18 can push the connector 2 to move to the middle of the positioning sleeve 3.

[0075] The difference between the usage method of this embodiment and that of Embodiment 1 lies only in the following: When the positioning sleeve 3 is engaged with the corresponding positioning ring 11, the repulsive force between the second magnet 18 and the first magnet 17 at the end of the corresponding side connector 2 can be changed by sliding the connecting tube 1, thereby ensuring that the positioning sleeve 3 and the positioning ring 11 are smoothly covered and positioned. Simultaneously, since the repulsive force between the first magnet 17 and the second magnet 18 is always present and can be adjusted by changing the position of the first magnet 17 through the connecting tube 1, the efficiency of installation and operation is improved. For patients in their physiological growth period or those undergoing concave-side stretching techniques due to scoliosis, this embodiment utilizes the repulsive force to actively change the length between the connecting tube 1 and the two connectors 2, thereby enabling adaptive adjustment based on changes in the patient's spine.

[0076] Example 5

[0077] like Figure 13As shown, the difference between the present embodiment and embodiment 2 is that the driving member is not arranged in the structure of the internal fixation device.

[0078] The difference between the use method of the present embodiment and the use method of embodiment 2 is that for the adjustment of the position of the connecting member 2, the positioning of the connecting member 2 is completed by directly moving the connecting member 2 to the predetermined position by the hand of the medical staff.

[0079] The above is only an embodiment of the present application, and the common knowledge of the specific structure and / or characteristics in the scheme is not described in detail. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can also be made, which should also be considered as the protection scope of the present application, and these will not affect the effect and practicality of the patent. The protection scope claimed in the present application should be subject to the content of its claims, and the specific implementation mode and the like recorded in the specification can be used to explain the content of the claims.

Claims

1. A length-adjustable spinal internal fixation device, characterized in that, include: Connecting pipe (1); Two connectors (2) are slidably connected to both sides of the connecting pipe (1); Two positioning sleeves (3) are slidably connected to the free ends of the corresponding connectors (2); Two flexible sleeves (8) are respectively set in the corresponding positioning sleeves (3). The two ends of the flexible sleeves (8) are connected between the left and right inner walls of the positioning sleeves (3). The inner diameter of the flexible sleeves (8) is the same as the inner diameter of the opening on the positioning sleeves (3). The flexible sleeves (8) are slidably sealed to the corresponding connectors (2). Two positioning rings (11) are slidably connected to the outer wall of the corresponding positioning sleeve (3). Each positioning ring (11) has a through hole at the top and a limit hole (12) at the bottom. Two bone screws (13), each of which is inserted into the limiting hole (12) of the corresponding positioning ring (11).

2. The length-adjustable spinal internal fixation device according to claim 1, characterized in that: The internal fixing device also includes a driving component, which is disposed inside the connecting tube (1). The driving component can drive the two connecting components (2) to move into the positioning sleeve (3) respectively.

3. The length-adjustable spinal internal fixation device according to claim 2, characterized in that: The flexible sleeve (8) has a groove (9) on its side wall, and the connector (2) has a limiting rod (10) that is slidably connected in the groove (9).

4. The length-adjustable spinal internal fixation device according to claim 2, characterized in that: The limiting hole (12) is a stepped hole or a conical hole.

5. The length-adjustable spinal internal fixation device according to claim 4, characterized in that: The positioning sleeve (3) has an annular groove (6) that communicates with the interior. The annular groove (6) is closely attached to one side of the retaining ring (4). The annular groove (6) has a vent hole (7) that communicates with the interior of the positioning sleeve (3). The edge of the annular groove (6) has an air cushion (5) that is flush with the outer surface of the positioning sleeve (3). The width of the air cushion (5) is smaller than the width of the positioning ring (11), and the thickness of the air cushion (5) is smaller than the depth of the annular groove (6).

6. The length-adjustable spinal internal fixation device according to claim 5, characterized in that: The positioning sleeve (3) is provided with a retaining ring (4), which is located on one side of the limiting hole (12) and close to the limiting hole (12).

7. A length-adjustable spinal internal fixation device according to any one of claims 2-6, characterized in that: The driving component includes a first magnet (17) and two second magnets (18). The first magnet (17) is located in the middle of the connecting tube (1), and the two second magnets (18) are respectively embedded in the ends of the connector (2). Both second magnets (18) generate a repulsive force with the first magnet (17). Under the premise of no other force, the repulsive force generated by the first magnet (17) and the second magnets (18) can push the connector (2) to move to the middle of the positioning sleeve (3).

8. A length-adjustable spinal internal fixation device according to any one of claims 2-6, characterized in that: The driving component is a bidirectional electric push rod (14), and the two push rods of the bidirectional electric push rod (14) abut against the ends of the two connecting parts (2) respectively.

9. The length-adjustable spinal internal fixation device according to claim 8, characterized in that: Each of the positioning sleeves (3) has a pressure sensor (15) embedded in its inner wall, and the pressure sensor (15) is electrically connected to the bidirectional electric push rod (14).

10. The length-adjustable spinal internal fixation device according to claim 9, characterized in that: Each of the positioning sleeves (3) has an air inlet at its end, and a one-way valve (16) is installed in the air inlet.

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