Skull flap fixation device with overload protection mechanism

Abstract

The utility model relates to medical instrument technical field discloses a skull bone flap fixing device with overload protection mechanism, including screw rod, and set up the lock piece and the lower lock piece on screw rod, the upper lock piece is connected with screw rod thread, the lower lock piece installs in the bottom of screw rod, the driving tool that still sets up with driving the upper lock piece rotation on screw rod, be equipped with overload protection mechanism in driving tool, this device can be in short time to multiple skull bone flap fixing device applies accurate clamping force, makes skull bone flap receive each upper lock piece's clamping force consistent, not only effectively improves the installation and dismounting efficiency of driving tool, and can eliminate the safety hidden danger that the indefiniteness caused by human factor brought in the process of screwing, has improved the security of installation process obviously, has effectively protected skull bone flap.

Description

Technical Field

[0001] This utility model relates to a cranial bone flap fixation device, and more particularly to a cranial bone flap fixation device with an overload protection mechanism. Background Technology

[0002] Cranioplasty is a common neurosurgical procedure. To ensure the stability and safety of cranial replantation, additional medical instruments are often used to fix the skull and bone flap, in order to restore the integrity of the skull, protect intracranial tissues, and promote the healing of the bone flap and skull.

[0003] Currently, common fixation medical devices on the market include titanium screws, titanium plates, and cranial locks. Traditional titanium screws and plates remain in the body after the skull has healed, requiring additional surgery for removal. Furthermore, failure to remove them promptly after they have served their purpose can lead to problems such as affecting the development of a child's skull and causing tissue burns due to their high thermal conductivity during outdoor activities.

[0004] Cranial locks: Tools used to fix skull bone flaps. The lower locking plate is placed on the inner side of the skull, outside the dura mater, and the upper locking plate is placed on the outer side of the skull. The two locking plates clamp the skull and bone flap for fixation. To ensure even force distribution, multiple cranial locks are used, and the angles between each lock must be equal. Currently, most commercially available cranial locks are made of biodegradable materials such as polylactic acid, which solves the problem of titanium screws and sheets remaining in the body. However, cranial locks have drawbacks during surgery, including uneven force distribution leading to poor fixation and affecting patient healing, complex operation that is not conducive to the surgeon's work, and the surgeon cannot determine whether the upper plate is tightened during the operation. Excessive or insufficient force exerted by the upper plate on the skull bone flap can pose a risk to the safety of the skull bone flap fixation. Utility Model Content

[0005] Therefore, the technical problem to be solved by this utility model is to provide a cranial bone flap fixation device with an overload protection mechanism to solve the above-mentioned technical problem.

[0006] The technical solution of this utility model is implemented as follows:

[0007] This utility model provides a cranial bone flap fixation device with an overload protection mechanism, including a screw, and an upper locking plate and a lower locking plate disposed on the screw. The upper locking plate is threadedly connected to the screw, and the lower locking plate is installed at the bottom of the screw. A driving tool for driving the upper locking plate to rotate is also sleeved on the screw, and the driving tool is provided with an overload protection mechanism.

[0008] Preferably, the driving tool includes a driving handle and a driving housing. The driving handle is rotatably disposed on the top of the driving housing. The rotating handle drives the driving housing to rotate. A driving post is provided at the bottom of the driving housing. A driving fastening hole is provided at the top of the upper locking plate. The size of the driving post matches the size of the driving fastening. The driving housing is inserted into the driving fastening hole through the driving post, and the driving handle drives the driving housing and the upper locking plate to rotate.

[0009] Preferably, the drive handle has a first channel at its center for the screw to pass through, the inner diameter of the first channel is larger than the outer diameter of the screw, and the outer wall of the drive handle has an annular groove, through which the drive handle is rotatably connected to the inner wall of the drive housing.

[0010] Preferably, the drive housing includes an upper latch, a middle main chamber, and a bottom second channel. The latch is disposed on the top inner wall of the drive housing. The drive handle is rotatably connected to the inner wall of the drive housing via an annular groove and the latch. The overload protection mechanism is installed in the main chamber, which communicates with the drive handle. The second channel is opened at the bottom of the drive housing, and the inner diameter of the second channel is larger than the outer diameter of the screw.

[0011] Preferably, the overload protection mechanism includes a lower gear, a lower meshing tooth, and a spring. The bottom of the drive handle is provided with an upper meshing tooth. The lower gear is located below the upper meshing tooth and is slidably connected to the inner wall of the drive housing. The lower meshing tooth is located at the top of the lower gear. The upper and lower meshing teeth mesh. The spring is located at the bottom of the lower gear, and the bottom end of the spring abuts against the inner bottom wall of the main chamber.

[0012] Preferably, the lower gear includes a positioning boss and a third channel. The positioning boss is located on both sides of the lower gear, and positioning chambers are formed on the inner walls of both sides of the drive housing. The positioning boss and the positioning chamber are slidably connected vertically. The lower gear is slidably connected vertically to the inner wall of the drive housing through the positioning boss and the positioning chamber. The third channel is located at the center of the lower gear, and the inner diameter of the third channel is larger than the outer diameter of the screw.

[0013] Preferably, the outer side of the drive housing is provided with anti-slip strips.

[0014] Preferably, the locking plate includes a first tooth, a first groove, a fourth channel, and a first thread. The first tooth is located at the bottom of the locking plate, the first groove is located at the top center of the locking plate, the fourth channel is located at the center of the first groove, and the first thread is located on the inner wall of the fourth channel.

[0015] Preferably, the screw includes a baffle, a second thread, and a rod body. The baffle is disposed at the bottom of the rod body, the second thread is disposed on the lower outer wall of the rod body, and the first thread and the second thread are threadedly connected.

[0016] Preferably, the lower locking piece includes a second groove, a second tooth, and a fifth channel. The second groove is located at the bottom center of the lower locking piece, the second tooth is located at the top of the lower locking piece, the fifth channel is located at the center of the second groove, the inner diameter of the fifth channel is larger than the outer diameter of the screw, the lower locking piece is sleeved on the bottom of the screw, and the baffle is installed in the second groove.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] This invention provides a cranial bone flap fixation device with an overload protection mechanism. With this structure, doctors do not need to judge the torque during use. They only need to apply a torque exceeding the threshold value to apply a precise clamping force to multiple cranial bone flap fixation devices in a short time. This ensures that the cranial bone flap is clamped by each locking plate with a consistent clamping force. This not only effectively improves the installation and disassembly efficiency of the driving tool, but also eliminates the safety hazards caused by the uncertainty of human factors during the tightening process. It significantly improves the safety of the installation process and effectively protects the cranial bone flap. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only preferred embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the internal structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal structure of the drive handle of this utility model;

[0022] Figure 3 This is a partial cross-sectional view of the drive housing of this utility model;

[0023] Figure 4 This is a schematic diagram of the internal structure of the drive housing of this utility model;

[0024] Figure 5 This is a schematic diagram of the internal structure of the lower gear of this utility model;

[0025] Figure 6 This is a three-dimensional structural diagram of the locking plate of this utility model;

[0026] Figure 7 This is a three-dimensional structural diagram of the screw of this utility model;

[0027] Figure 8 This is a three-dimensional structural diagram of the lower locking piece of this utility model;

[0028] Figure 9 This is an exploded view of the present invention;

[0029] Figure 10 This is a schematic diagram of the internal structure of the present invention when the torque threshold value is reached;

[0030] Figure 11 This is a schematic diagram of the structure of the present invention when the driving tool is removed after the bone flap fixation is completed;

[0031] Figure 12 In order to be in Figure 11 A schematic diagram of the structure for cutting the screw based on the above;

[0032] Figure 13 In order to be in Figure 12 The diagram shows the structure of the hot-pressed screw.

[0033] In the diagram, 1. Screw; 11. Baffle; 12. Second thread; 13. Rod body; 2. Upper locking plate; 21. Drive fastening hole; 22. First tooth; 23. First groove; 24. Fourth channel; 25. First thread; 3. Lower locking plate; 31. Second groove; 32. Second tooth; 33. Fifth channel; 4. Drive tool; 41. Drive handle; 411. First channel; 412. Annular groove; 413. Upper meshing tooth; 42. Drive housing; 421. Locking protrusion; 422. Main chamber; 423. Second channel; 424. Positioning chamber; 425. Anti-slip strip; 43. Drive column; 5. Overload protection mechanism; 51. Lower gear; 52. Lower meshing tooth; 53. Spring; 54. Positioning boss; 55. Third channel. Detailed Implementation

[0034] To better understand the technical content of this utility model, specific embodiments are provided below, and the utility model will be further described in conjunction with the accompanying drawings.

[0035] See Figures 1 to 13 This utility model provides a cranial bone flap fixation device with an overload protection mechanism 5, including a screw 1, and an upper locking plate 2 and a lower locking plate 3 disposed on the screw 1. The upper locking plate 2 is threadedly connected to the screw 1, and the lower locking plate 3 is installed at the bottom of the screw 1. A driving tool 4 for driving the upper locking plate 2 to rotate is also sleeved on the screw 1, and the driving tool 4 is provided with an overload protection mechanism 5.

[0036] After removing the skull flap, place the skull flap fixation device along the bone window line. The lower locking plate 3 should be located between the dura mater and the skull. Then, reposition the bone flap and use the driving tool 4 to tighten the upper locking plate 2 downwards. This allows the upper locking plate 2 and the lower locking plate 3 to clamp and fix the bone flap. Under the action of the overload protection mechanism 5, it can prevent the upper locking plate 2 from exerting too much or too little force on the skull flap, which could cause hidden dangers to the safety of the skull flap fixation. Finally, use an electrocautery pen to heat-melt and cut off the excess screw 1, and flatten it to complete the fixation of the entire skull flap.

[0037] The driving tool 4 includes a driving handle 41 and a driving housing 42. The driving handle 41 is rotatably disposed on the top of the driving housing 42. The rotating handle drives the driving housing 42 to rotate. A driving post 43 is provided at the bottom of the driving housing 42. A driving fastening hole 21 is provided on the top of the upper locking plate 2. The size of the driving post 43 matches the size of the driving fastening. The driving housing 42 is inserted into the driving fastening hole 21 through the driving post 43, and the driving handle 41 drives the driving housing 42 and the upper locking plate 2 to rotate.

[0038] The drive handle 41 has a first channel 411 at its center for the screw 1 to pass through. The inner diameter of the first channel 411 is larger than the outer diameter of the screw 1. The outer wall of the drive handle 41 has an annular groove 412. The drive handle 41 is rotatably connected to the inner wall of the drive housing 42 through the annular groove 412.

[0039] The drive housing 42 includes an upper locking protrusion 421, a middle main chamber 422, and a bottom second channel 423. The locking protrusion 421 is located on the top inner wall of the drive housing 42 and engages with the annular groove 412 of the drive handle 41, thereby restricting the drive handle 41 from moving independently in the vertical direction. The drive handle 41 is rotatably connected to the inner wall of the drive housing 42 through the annular groove 412 and the locking protrusion 421. The contact surfaces of the locking protrusion 421 and the annular groove 412 are smooth surfaces to reduce friction. The overload protection mechanism 5 is installed in the main chamber 422, which communicates with the drive handle 41. The second channel 423 is located at the bottom of the drive housing 42, and the inner diameter of the second channel 423 is larger than the outer diameter of the screw 1.

[0040] The overload protection mechanism 5 includes a lower gear 51, a lower meshing tooth 52, and a spring 53. The bottom of the drive handle 41 is provided with an upper meshing tooth 413. The lower gear 51 is located below the upper meshing tooth 413 and is slidably connected to the inner wall of the drive housing 42. The lower meshing tooth 52 is located at the top of the lower gear 51. The upper meshing tooth 413 and the lower meshing tooth 52 mesh. The spring 53 is located at the bottom of the lower gear 51, and the bottom end of the spring 53 abuts against the inner bottom wall of the main chamber 422.

[0041] The lower gear 51 includes a positioning boss 54 and a third channel 55. The positioning boss 54 is located on both sides of the lower gear 51. Positioning chambers 424 are formed on the inner walls of both sides of the drive housing 42. The positioning boss 54 and the positioning chambers 424 are slidably connected vertically. The lower gear 51 is slidably connected vertically to the inner wall of the drive housing 42 through the positioning boss 54 and the positioning chambers 424. The third channel 55 is located at the center of the lower gear 51. The inner diameter of the third channel 55 is larger than the outer diameter of the screw 1.

[0042] The outer side of the drive housing 42 is provided with anti-slip strips 425.

[0043] The upper locking plate 2 includes a first tooth 22, a first groove 23, a fourth channel 24 and a first thread 25. The first tooth 22 is located at the bottom of the upper locking plate 2, the first groove 23 is located at the top center of the upper locking plate 2, the fourth channel 24 is located at the center of the first groove 23, and the first thread 25 is located on the inner wall of the fourth channel 24.

[0044] The screw 1 includes a baffle 11, a second thread 12, and a rod body 13. The baffle 11 is located at the bottom of the rod body 13, and the second thread 12 is located on the lower outer wall of the rod body 13. The first thread 25 is threadedly connected to the second thread 12.

[0045] The lower locking plate 3 includes a second groove 31, a second tooth 32, and a fifth channel 33. The second groove 31 is located at the bottom center of the lower locking plate 3, the second tooth 32 is located at the top of the lower locking plate 3, and the fifth channel 33 is located at the center of the second groove 31. The inner diameter of the fifth channel 33 is larger than the outer diameter of the screw 1. The lower locking plate 3 is sleeved on the bottom of the screw 1, and the baffle 11 is installed in the second groove 31.

[0046] It should be noted that the inner diameters of the first channel 411, the second channel 423, the third channel 55, and the fifth channel 33 in this device are all larger than the outer diameter of the screw 1, allowing the drive tool 4 to be freely and quickly fitted onto and removed from the screw 1. All structural materials used in this invention are PLGA, which can be absorbed and degraded within the human body.

[0047] The working process of this cranial bone flap fixation device is as follows:

[0048] (1) Placement of cranial locks (i.e., this cranial flap fixation device): After removing the cranial flap, place at least 3 cranial lock products along the bone window line, with the lower lock plate 3 positioned between the dura mater and the skull. (Note: The cranial lock products should be evenly placed around the bone flap. Therefore, if using 3 cranial lock products, they should be placed at a 120° angle; if using 4 cranial lock products, they should be placed at a 90° angle.)

[0049] (2) Reposition the bone flap.

[0050] (3) Rotation and Fixation: Complete the rotation and fixation of all skull locks. Ensure that the axis of screw 1 is perpendicular to the incision. Insert the drive tool 4 from the top of screw 1, so that the drive post 43 at the bottom of the drive housing 42 is inserted into the drive fastening hole 21 of the upper locking plate 2. Gently hold the upper end of screw 1 with one hand to make the lower locking plate 3 fit tightly against the inner surface of the skull. At the same time, rotate the drive handle 41 clockwise with the other hand (two people can also cooperate to operate). At this time, the torque has not yet reached the threshold value. The upper meshing tooth 413 of the drive handle 41 meshes with the lower meshing tooth 52. The lower gear 51 drives the entire drive housing 42 to rotate synchronously, driving the upper locking plate 2 to rotate downward until the upper locking plate 2 fits tightly against the upper surface of the skull and reaches the torque threshold value. A "clicking" sound is emitted when the clamping torque exceeds the threshold. As the upper meshing tooth 413 of the drive handle 41 continues to rotate, the lower meshing tooth 52 will be subjected to the torque applied by the upper meshing tooth 413. The drive housing 42 can no longer move down and therefore cannot rotate. The torque on the lower meshing tooth 52 will act on the lower gear 51 and push the lower gear 51 to move down along the positioning chamber 424 to compress the spring 53. This causes the upper meshing tooth 413 and the lower meshing tooth 52 to slip and no longer apply torque to the upper locking plate 2, and a "clicking" sound is emitted, indicating that the fastening operation is completed, and the drive tool 4 is removed.

[0051] (4) Cut off screw 1: Use an electrostatic precipitator to cut off screw 1, leaving a 2-3 mm tail end, see [link to relevant documentation]. Figure 12 .

[0052] (5) Ironing the tail end: Use an ironing tip to iron the remaining tail end flat into the first groove 23 of the locking plate 2, so that the tail end of the screw 1 is flush with the top of the locking plate 2, while locking the position of the locking plate 2 to prevent the locking plate 2 from rotating upward, thereby better maintaining the fixing effect. See Figure 13 .

[0053] With the aforementioned mechanism, during use, doctors do not need to judge the torque; they only need to apply a torque exceeding the threshold value to apply precise clamping force to multiple skull flap fixation devices in a short time. This ensures that the skull flap is subjected to consistent clamping force from each locking plate 2, effectively improving the installation and disassembly efficiency of the drive tool 4. It also eliminates safety hazards caused by the uncertainty of human factors during tightening, significantly improving the safety of the installation process and effectively protecting the skull flap. Furthermore, by setting different threshold torque values ​​using different spring stiffness coefficients 53, this installation mechanism can be applied to skull flaps of different hardness. Doctors can select an installation tool with an appropriate threshold value before surgery, further improving the stability of clamping.

[0054] Compared to existing products that fail after a single use, the driving tool 4 of this invention can repeatedly switch from the driving state to the failure state, resulting in higher tightening efficiency and the ability to be used multiple times to tighten multiple skull locks.

[0055] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A skull flap fixation device with an overload protection mechanism, characterized in that It includes a screw (1), and an upper locking plate (2) and a lower locking plate (3) disposed on the screw (1). The upper locking plate (2) is threadedly connected to the screw (1), and the lower locking plate (3) is installed at the bottom of the screw (1). A driving tool (4) for driving the upper locking plate (2) to rotate is also sleeved on the screw (1). An overload protection mechanism (5) is provided inside the driving tool (4).

2. The skull flap fixation device with overload protection mechanism of claim 1, wherein, The driving tool (4) includes a driving handle (41) and a driving housing (42). The driving handle (41) is rotatably disposed on the top of the driving housing (42). The rotating handle drives the driving housing (42) to rotate. A driving post (43) is provided at the bottom of the driving housing (42). A driving fastening hole (21) is provided on the top of the upper locking plate (2). The size of the driving post (43) matches the size of the driving fastening. The driving housing (42) is inserted into the driving fastening hole (21) through the driving post (43), and the driving handle (41) drives the driving housing (42) and the upper locking plate (2) to rotate.

3. A skull flap fixation device with an overload protection mechanism according to claim 2, characterized in that The drive handle (41) has a first channel (411) at its center for the screw (1) to pass through. The inner diameter of the first channel (411) is larger than the outer diameter of the screw (1). The outer wall of the drive handle (41) is provided with an annular groove (412). The drive handle (41) is rotatably connected to the inner wall of the drive housing (42) through the annular groove (412).

4. The skull flap fixation device with overload protection mechanism of claim 3, wherein, The drive housing (42) includes an upper latch (421), a middle main chamber (422), and a bottom second channel (423). The latch (421) is located on the top inner wall of the drive housing (42). The drive handle (41) is rotatably connected to the inner wall of the drive housing (42) through an annular groove (412) and the latch (421). The overload protection mechanism (5) is installed in the main chamber (422), which is connected to the drive handle (41). The second channel (423) is located at the bottom of the drive housing (42), and the inner diameter of the second channel (423) is larger than the outer diameter of the screw (1).

5. A skull flap fixation device with an overload protection mechanism according to claim 4, characterized in that The overload protection mechanism (5) includes a lower gear (51), a lower meshing tooth (52), and a spring (53). The bottom of the drive handle (41) is provided with an upper meshing tooth (413). The lower gear (51) is located below the upper meshing tooth (413) and is slidably connected to the inner wall of the drive housing (42). The lower meshing tooth (52) is located at the top of the lower gear (51). The upper meshing tooth (413) and the lower meshing tooth (52) mesh. The spring (53) is located at the bottom of the lower gear (51). The bottom end of the spring (53) abuts against the inner bottom wall of the main chamber (422).

6. A skull flap fixation device with an overload protection mechanism according to claim 5, characterized in that The lower gear (51) includes a positioning boss (54) and a third channel (55). The positioning boss (54) is located on both sides of the lower gear (51). The inner walls of both sides of the drive housing (42) are provided with positioning chambers (424). The positioning boss (54) and the positioning chambers (424) are slidably connected vertically. The lower gear (51) is slidably connected vertically to the inner wall of the drive housing (42) through the positioning boss (54) and the positioning chambers (424). The third channel (55) is located at the center of the lower gear (51). The inner diameter of the third channel (55) is larger than the outer diameter of the screw (1).

7. A cranial bone flap fixation device with overload protection mechanism according to claim 2, characterized in that, The outer side of the drive housing (42) is provided with anti-slip strips (425).

8. The skull flap fixation device with overload protection mechanism of claim 1, wherein, The upper locking plate (2) includes a first tooth (22), a first groove (23), a fourth channel (24) and a first thread (25). The first tooth (22) is located at the bottom of the upper locking plate (2), the first groove (23) is located at the top center of the upper locking plate (2), the fourth channel (24) is located at the center of the first groove (23), and the first thread (25) is located on the inner wall of the fourth channel (24).

9. A skull flap fixation device with an overload protection mechanism according to claim 8, characterized in that The screw (1) includes a baffle (11), a second thread (12) and a rod (13). The baffle (11) is located at the bottom of the rod (13), and the second thread (12) is located on the lower outer wall of the rod (13). The first thread (25) is threadedly connected to the second thread (12).

10. The skull flap fixation device with overload protection mechanism of claim 9, wherein, The lower locking piece (3) includes a second groove (31), a second tooth (32), and a fifth channel (33). The second groove (31) is located at the bottom center of the lower locking piece (3), the second tooth (32) is located at the top of the lower locking piece (3), and the fifth channel (33) is opened at the center of the second groove (31). The inner diameter of the fifth channel (33) is larger than the outer diameter of the screw (1). The lower locking piece (3) is sleeved on the bottom of the screw (1), and the baffle (11) is installed in the second groove (31).

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