Spinal immobilization mechanism and lumbar disc herniation model construction method using same

Abstract

The application discloses a lumbar disc herniation model construction method and a spine limiting mechanism. The spine limiting mechanism comprises a fixing mechanism, the fixing mechanism comprises a first fixing group, a second fixing group and a third fixing group, further comprises a activity degree adjusting mechanism, the activity degree adjusting mechanism comprises a first connecting plate and a second connecting plate, the top of the two clamps of the first fixing group is connected through the first bolt passing through the round hole of the first connecting plate, the top of the two clamps of the second fixing group is connected through the second bolt passing through the adjusting hole of the first connecting plate and the round hole of the second connecting plate, and the top of the two clamps of the third fixing group is connected through the third bolt passing through the adjusting hole of the second connecting plate. Through the setting of the activity degree adjusting mechanism, the three adjacent spines have the activity degree.

Description

Technical Field

[0001] This invention relates to the field of animal experimental instruments, specifically to a lumbar spine fixation device. Background Technology

[0002] The chronic compression of the dorsal root ganglion (CCD) model is currently one of the recognized models for studying lumbar disc herniation. This model requires inserting a titanium alloy rod into the intervertebral foramen to mechanically compress the dorsal root ganglion. However, this model only simulates the peripheral nerve entrapment state and cannot simulate the "muscle-muscle imbalance" state of lumbar disc herniation.

[0003] Chinese Patent Publication No. CN211213442U discloses an external connection and fixation device for a rat model of subluxation of the spine. The device consists of two pairs of spinous process connecting plates, two pairs of connecting plates, and four pairs of screws and nuts. After installation, the spinal vertebrae are completely fixed, losing all mobility, which is detrimental to simulating lumbar disc herniation. Currently, there is a lack of an animal model for lumbar disc herniation that can simulate a state of "muscle-bone imbalance." Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a spinal restraint mechanism, which has solved at least one of the above-mentioned technical problems.

[0005] This invention provides a method for constructing a lumbar disc herniation model using a spinal positioning mechanism, which solves at least one of the above-mentioned technical problems.

[0006] The technical solution of the present invention is: a spinal limiting mechanism, including a fixing mechanism, characterized in that the fixing mechanism includes a first fixing group for fixing to the spinous process of the fourth lumbar vertebra of an experimental mouse, a second fixing group for fixing to the spinous process of the fifth lumbar vertebra of an experimental mouse, and a third fixing group for fixing to the spinous process of the sixth lumbar vertebra of an experimental mouse.

[0007] The first fixing group, the second fixing group and the third fixing group each include two clamping plates arranged side by side. The bottom of the two clamping plates is provided with mounting holes. The bottom of the two clamping plates is clamped to the opposite side of the corresponding ratchet by mounting bolts passing through the mounting holes.

[0008] It also includes a range of motion adjustment mechanism, which includes a first connecting plate for connecting the first fixing group and the second fixing group and a second connecting plate for connecting the second fixing group and the third fixing group; the first connecting plate and the second connecting plate are respectively provided with a round hole and an adjustment hole at both ends;

[0009] The tops of the two clamping plates of the first fixing group are clamped on both sides of one end of the first connecting plate and connected by a first bolt passing through the round hole of the first connecting plate.

[0010] The tops of the two clamping plates of the second fixing group are clamped on both sides of the other end of the first connecting plate and one end of the second connecting plate, and are connected by a second bolt passing through the adjustment hole of the first connecting plate and the round hole of the second connecting plate.

[0011] The tops of the two clamping plates of the third fixing group are clamped on both sides of the second connecting plate and connected by a third bolt passing through the adjustment hole of the second connecting plate.

[0012] This invention achieves mobility between three adjacent vertebrae by setting up a range of motion adjustment mechanism, thus avoiding relative fixation between the three adjacent vertebrae.

[0013] This invention enables the vertebral body to move slightly, which better reflects the reduced mobility of lumbar disc herniation rather than the complete loss of mobility in clinical manifestations. It can more realistically simulate lumbar disc herniation and achieve the simulation of the "muscle and bone imbalance" state.

[0014] More preferably, the first fixing group, the second fixing group, and the third fixing group are arranged from front to back;

[0015] The fixing plate includes a base, and the bottom of the base is provided with an inclined portion that slopes downward from back to front, and the inclined portion is provided with the mounting hole;

[0016] The angle between the inclined portion of the fixing plate of the first fixing group and the base is greater than the angle between the inclined portion of the fixing plate of the second fixing group and the base, and the angle between the inclined portion of the fixing plate of the second fixing group and the base is greater than the angle between the inclined portion of the fixing plate of the third fixing group and the base.

[0017] A further preferred embodiment includes a titanium alloy rod for insertion into the intervertebral foramen;

[0018] It also includes a linkage mechanism, which includes a washer passing through the second bolt, a transmission wire, a tensioning reel, and a transmission wheel;

[0019] The tightening reel is installed at the end of the second fixing group adjacent to the mounting bolt;

[0020] One end of the transmission wire is wound around the winding reel, and the winding reel is equipped with a reset mechanism for tightening the transmission wire.

[0021] The other end of the transmission wire is mounted on the gasket, and the transmission wire is sleeved on the transmission wheel;

[0022] The transmission wire is provided with toothed protrusions, and the transmission wheel is provided with meshing teeth that match the toothed protrusions. The inner side of the transmission wheel is threadedly connected to the titanium alloy rod.

[0023] The winding reel is mounted on the base, and the drive wheel is rotatably mounted on the base.

[0024] This allows the movement of the titanium alloy rod to be driven by spinal movement, thereby compressing the experimental mouse.

[0025] When the spine of the experimental rats moved, the second fixed group swung, pulling the transmission wire, which drove the transmission wheel to rotate, and then drove the titanium alloy rod to move axially and insert into the intervertebral foramen.

[0026] More preferably, the transmission wheel includes a transmission part and a bearing part arranged adjacent to each other in the axial direction, and the transmission part is provided with the meshing teeth and a threaded hole for threaded connection of the titanium alloy rod;

[0027] The bearing portion is rotatably connected to the base.

[0028] More preferably, the length of the first fixed group is less than the length of the second fixed group and the length of the third fixed group;

[0029] The length of the third fixed group is less than the length of the second fixed group.

[0030] The method for constructing a lumbar disc herniation model using the aforementioned spinal positioning mechanism is characterized by comprising the following steps:

[0031] Step 1: Drill holes in the spinous processes of the fourth, fifth, and sixth lumbar vertebrae, and connect the first, second, and third fixation groups to the spinous processes of the fourth, fifth, and sixth lumbar vertebrae of the experimental mouse using bolts.

[0032] Step 2: Connect the first fixing group and the second fixing group using the first connecting plate;

[0033] Step 3: Connect the second fixing group and the third fixing group using the second connecting plate.

[0034] More preferably, in step four, a titanium alloy rod is inserted, the titanium alloy rod being threaded with a guide wheel, and the base is installed near the mounting bolts of the second fixing group;

[0035] Install the gasket onto the second bolt of the second fixing group.

[0036] Beneficial effects:

[0037] This invention can better simulate the pathological state of lumbar disc herniation with "muscle and bone imbalance" accompanied by nerve root compression, and extends it to the field of magnetic resonance imaging research, thus expanding the practical application scope of the model. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a specific embodiment 1 of the present invention;

[0039] Figure 2 This is a schematic diagram of a structure from another perspective of a specific embodiment 1 of the present invention;

[0040] Figure 3 This is a partial exploded view of a specific embodiment 1 of the present invention;

[0041] Figure 4 This is a schematic diagram showing the changes in rat spinal stiffness in a specific embodiment 3 of the present invention;

[0042] Figure 5 This is a partial structural schematic diagram of a specific embodiment 2 of the present invention.

[0043] In the diagram: 1 is the first fixing group, 2 is the second fixing group, 3 is the third fixing group, 4 is the first connecting plate, 5 is the second connecting plate, 61 is the transmission wire, 62 is the transmission wheel, 63 is the titanium alloy rod, 64 is the base, and 65 is the tensioning reel. Detailed Implementation

[0044] The present invention will now be further described with reference to the accompanying drawings.

[0045] See Figures 1 to 3Specific embodiment 1, a spinal limiting mechanism, includes a fixation mechanism comprising a first fixation group 1 for fixing to the spinous process of the fourth lumbar vertebra of a laboratory mouse, a second fixation group 2 for fixing to the spinous process of the fifth lumbar vertebra of a laboratory mouse, and a third fixation group 3 for fixing to the spinous process of the sixth lumbar vertebra of a laboratory mouse; each of the first fixation group 1, the second fixation group 2, and the third fixation group 3 includes two clamping plates arranged side by side, with mounting holes at the bottom of the two clamping plates, and the bottoms of the two clamping plates are clamped to the opposite sides of the corresponding spinous processes by mounting bolts passing through the mounting holes; it also includes a range of motion adjustment mechanism, which includes a first connecting plate 4 for connecting the first fixation group 1 and the second fixation group 2 and A second connecting plate 5 is used to connect the second fixing group 2 and the third fixing group 3; the first connecting plate 4 and the second connecting plate 5 have round holes and adjustment holes at both ends respectively; the tops of the two clamping plates of the first fixing group 1 are clamped on both sides of one end of the first connecting plate 4 and connected by a first bolt passing through the round hole of the first connecting plate 4; the tops of the two clamping plates of the second fixing group 2 are clamped on both sides of the other end of the first connecting plate 4 and one end of the second connecting plate 5 and connected by a second bolt passing through the adjustment hole of the first connecting plate 4 and the round hole of the second connecting plate 5; the tops of the two clamping plates of the third fixing group 3 are clamped on both sides of the second connecting plate 5 and connected by a third bolt passing through the adjustment hole of the second connecting plate 5. This invention, through the setting of the mobility adjustment mechanism, achieves mobility between three adjacent vertebrae, avoiding relative fixation between the three adjacent vertebrae. This invention allows the vertebral body to move slightly, which is more in line with the reduced mobility of lumbar disc herniation, rather than the complete loss of mobility, and can more realistically simulate lumbar disc herniation, achieving the simulation of a "musculoskeletal imbalance" state.

[0046] The adjusting hole is either oblong or arc-shaped. The length of the oblong hole is parallel to the length direction of both the first and second connecting plates. At least three limiting protrusions can be provided on the inner side of the adjusting hole along its length direction to facilitate bolt positioning.

[0047] The first fixing group 1, the second fixing group 2, and the third fixing group 3 are arranged from front to back; the fixing plate includes a base, and the bottom of the base is provided with an inclined part that is inclined downward from back to front, and the inclined part is provided with a mounting hole; the angle between the inclined part of the fixing plate of the first fixing group 1 and the base is greater than the angle between the inclined part of the fixing plate of the second fixing group 2 and the base, and the angle between the inclined part of the fixing plate of the second fixing group 2 and the base is greater than the angle between the inclined part of the fixing plate of the third fixing group 3 and the base.

[0048] The angle between the inclined part of the first fixing group 1 and the substrate is 137°-138°; the angle between the inclined part of the second fixing group 2 and the substrate is 142°-143°; and the angle between the inclined part of the third fixing group 3 and the substrate is 154°-155°.

[0049] The length of the first fixing group 1 is less than the length of the second fixing group 2 and the third fixing group 3; the length of the third fixing group 3 is less than the length of the second fixing group 2. Specifically, the length of the fixing plate of the first fixing group 1 in the extension direction of the substrate is 19.5mm-21mm; the length of the fixing plate of the second fixing group 2 in the extension direction of the substrate is 20.5mm-22mm; and the length of the fixing plate of the third fixing group 3 in the extension direction of the substrate is 20mm-21mm. The width of the fixing plate is 3.8mm-4.2mm. The thickness of the fixing plate is 1mm-1.1mm.

[0050] The center distance between the circular hole and the adjustment hole of the first connecting plate 4 is 7.3mm-7.5mm. The longitudinal width of the first connecting plate 4 and the second connecting plate 5 is 4.8mm-5.1mm.

[0051] The fixing plate is made of plastic. Suitable for use in MRI settings, its lightweight material minimizes the impact of weight on the rat's lumbar spine. The bolts are made of titanium alloy. The first connecting plate 4 and the second connecting plate 5 are made of plastic.

[0052] The fixing plates of the three fixing assemblies have different marking structures, including at least one of the following: printed coating, grooves, and holes. This facilitates identification and prevents incorrect assembly. For example... Figure 1 as well as Figure 3 The fixing plate has marking structures to indicate L4, L5, and L6. These markings are used to identify the positions of the spikes fixed by different fixing plates.

[0053] See Figure 5In specific embodiment 2, based on specific embodiment 1, it further includes a titanium alloy rod 63 for insertion into the intervertebral foramen; it also includes a linkage mechanism, which includes a washer passing through the second bolt, a transmission wire 61, a tightening reel 65, and a transmission wheel 62; the tightening reel 65 is installed at the end of the second fixing group adjacent to the mounting bolt; one end of the transmission wire 61 is wound around the tightening reel 65, and a reset mechanism for tightening the transmission wire 61 is installed on the tightening reel 65; the other end of the transmission wire 61 is installed on the washer, and the transmission wire 61 is sleeved on the transmission wheel 62; the transmission wire 61 has toothed protrusions, and the transmission wheel 62 has meshing teeth that match the toothed protrusions; the inner side of the transmission wheel 62 is threadedly connected to the titanium alloy rod 63; the tightening reel 65 is installed on the base 64, and the transmission wheel 62 is rotatably installed on the base 64. This facilitates the movement of the titanium alloy rod 63 during spinal movement, thereby achieving compression on the experimental mouse. When the mouse's spine moves, the second fixation group swings, pulling the transmission wire 61, which in turn rotates the transmission wheel 62, causing the titanium alloy rod 63 to move axially and extend into the intervertebral foramen. The base has mounting holes. The base is mounted on the end of the second fixation group near the mounting bolt through the mounting holes. The second fixation group swings around the mounting holes.

[0054] The transmission wheel 62 includes a transmission part and a bearing part arranged adjacent to each other in the axial direction. The transmission part is provided with meshing teeth and a threaded hole for threaded connection of titanium alloy rod 63; the bearing part is rotatably connected to the base 64.

[0055] Specific embodiment 3, the method for constructing a lumbar disc herniation model using the aforementioned spinal positioning mechanism, includes the following steps:

[0056] Step 1: Drill holes in the spinous processes of the fourth, fifth, and sixth lumbar vertebrae, and connect the first, second, and third fixation groups to the spinous processes of the fourth, fifth, and sixth lumbar vertebrae of the experimental mouse using bolts.

[0057] Step 2: Connect the first fixing group and the second fixing group using the first connecting plate;

[0058] Step 3: Connect the second fixing group and the third fixing group using the second connecting plate.

[0059] To verify the success of the rat model of lumbar disc herniation caused by "muscle and bone imbalance", three experimental groups were prepared:

[0060] 1. Naive group: This group is not processed.

[0061] 2. "Musculoskeletal Imbalance" Group (TBI): The skin was cut open, and the soft tissue around the spinous processes and articular processes was dissected. An auxiliary fixation mechanism was constructed and connected to the spinous processes of the fourth, fifth, and sixth lumbar vertebrae. No titanium alloy rods were placed.

[0062] 3. "Musculoskeletal Imbalance" LDH Group (TBILDH): Using the above steps, the auxiliary fixation mechanism was connected to the spinous processes of the fourth, fifth, and sixth lumbar vertebrae, and a titanium alloy rod was inserted into the intervertebral foramen.

[0063] The experiment used pain behavior and spinal stiffness testing for cross-validation, and the relevant results are as follows:

[0064] 1. Pain Behavioral Science

[0065] 1.1 Changes in Paw Withdraw Threshold (PWT)

[0066] Before the experiment, behavioral tests were performed on rats in each group, and baseline values ​​were collected. After modeling, rats were observed for 3 days, and post-modeling weight loss (PWT) was measured in the right hind paw of the rats starting 3 days later. The tests were conducted on days 3, 7, 10, and 14 after modeling (inclusive). Results are expressed as mean ± standard deviation (X ± SD). Changes in PWT in each group are shown in Table 1-1.

[0067] There were no statistically significant differences in baseline PWT values ​​among the three groups of rats before modeling (P>0.05). The Naive group showed no significant change in PWT (P>0.05); the TBILDH group showed a significant decrease in PWT on day 3 after modeling, with a marked difference compared to the Naive group (P<0.01), reaching its lowest point between days 10 and 14. Compared to the Naive group, the TBI group showed a decrease in PWT post-surgery, with a similar trend to the TBILDH group, but its PWT values ​​at all post-surgery time points were higher than those in the TBILDH group (P<0.05).

[0068] Table 1-1 Changes in PWT in the right hind paw of rats with the "muscle-bone imbalance" LDH model

[0069]

[0070] Note: Compared with the TBILDH group, *P<0.05, **P<0.01. Compared with the TBILDH group, ##P<0.01, ###P<0.001.

[0071] 1.2 Changes in PawWithdraw Latency (PWL) of Heat Shrink Foot Reflex

[0072] The time points and data presentation methods for PWL testing are the same as for PWT. The changes in PWL in each group of rats are shown in Table 1-2.

[0073] There were no statistically significant differences in baseline PWL values ​​among the three groups of rats before modeling (P>0.05). After modeling, the PWL in the TBILDH group showed a decreasing trend, reaching its lowest level on day 14. On days 7 and 14 post-surgery, the PWL in the TBILDH group was significantly lower than that in the Naive group (P<0.01). The TBI group showed a similar decreasing trend to the TBILDH group post-surgery, but remained higher than the TBILDH group. On days 10 and 14 post-surgery, the differences between the TBI group and the TBILDH group were statistically significant (P<0.05).

[0074] Table 1-2 Changes in PWL in the right hind paw of rats in the LDH model of "musculoskeletal imbalance"

[0075]

[0076] Note: Compared with the TBILDH group, *P<0.05, **P<0.01; compared with the Naive group, ##P<0.01, ###P<0.01.

[0077] 2. Spinal stiffness test

[0078] The results of spinal stiffness testing showed that there were no significant differences in baseline values ​​among the three groups of rats before modeling (P>0.05). Seven days after modeling, the spinal stiffness of the TBI and TBILDH groups increased significantly, showing an increasing trend over time. Significant differences were observed between the TBI and TBILDH groups at 7 and 14 days compared to the Naive group (P<0.05). There were no significant differences between the TBI and TBILDH groups at any time point (P<0.05). The results are shown in Tables 1-3 and... Figure 4 .

[0079] Table 1-3 Changes in spinal stiffness in the LDH model of "musculoskeletal imbalance"

[0080]

[0081] Note: *P<0.05 compared with the Naive group.

[0082] The results showed that the "musculoskeletal imbalance" LDH model could reduce the mechanical paw reflex threshold and thermal constriction reflex latency in rats, and the pain behavior could persist and remain stable after modeling. Furthermore, the "musculoskeletal imbalance" LDH model could increase spinal stiffness in rats, simulating the clinical pathological condition of "muscle misalignment and bone displacement." In conclusion, the "musculoskeletal imbalance" LDH model is an ideal animal model for lumbar disc herniation.

[0083] Specific embodiment 4, based on specific embodiment 2, describes a method for constructing a lumbar disc herniation model using a spinal positioning mechanism, comprising the following steps:

[0084] Step 1: Drill holes in the spinous processes of the fourth, fifth, and sixth lumbar vertebrae, and connect the first, second, and third fixation groups to the spinous processes of the fourth, fifth, and sixth lumbar vertebrae of the experimental mouse using bolts.

[0085] Step 2: Connect the first fixing group and the second fixing group using the first connecting plate;

[0086] Step 3: Connect the second fixing group and the third fixing group using the second connecting plate;

[0087] Step 4: Insert the titanium alloy rod, which has a guide wheel threaded onto it, and install the base near the mounting bolts of the second fixing group.

[0088] Install the gasket onto the second bolt of the second fixing group.

[0089] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Spinal immobilization apparatus comprising a fixation apparatus, characterized in that The fixation mechanism includes a first fixation group for fixing to the spinous process of the fourth lumbar vertebra of the experimental mouse, a second fixation group for fixing to the spinous process of the fifth lumbar vertebra of the experimental mouse, and a third fixation group for fixing to the spinous process of the sixth lumbar vertebra of the experimental mouse. The first fixing group, the second fixing group and the third fixing group each include two clamping plates arranged side by side. The bottom of the two clamping plates is provided with mounting holes. The bottom of the two clamping plates is clamped to the opposite side of the corresponding ratchet by mounting bolts passing through the mounting holes. It also includes a range of motion adjustment mechanism, which includes a first connecting plate for connecting the first fixing group and the second fixing group and a second connecting plate for connecting the second fixing group and the third fixing group; the first connecting plate and the second connecting plate are respectively provided with a round hole and an adjustment hole at both ends; The tops of the two clamping plates of the first fixing group are clamped on both sides of one end of the first connecting plate and connected by a first bolt passing through the round hole of the first connecting plate. The tops of the two clamping plates of the second fixing group are clamped on both sides of the other end of the first connecting plate and one end of the second connecting plate, and are connected by a second bolt passing through the adjustment hole of the first connecting plate and the round hole of the second connecting plate. The tops of the two clamping plates of the third fixing group are clamped on both sides of the second connecting plate and connected by a third bolt passing through the adjustment hole of the second connecting plate; It also includes a titanium alloy rod for insertion into the intervertebral foramen; It also includes a linkage mechanism, which includes a washer passing through the second bolt, a transmission wire, a tensioning reel, and a transmission wheel; The tightening reel is installed at the end of the second fixing group adjacent to the mounting bolt; One end of the transmission wire is wound around the winding reel, and the winding reel is equipped with a reset mechanism for tightening the transmission wire. The other end of the transmission wire is mounted on the gasket, and the transmission wire is sleeved on the transmission wheel; The transmission wire is provided with toothed protrusions, and the transmission wheel is provided with meshing teeth that match the toothed protrusions. The inner side of the transmission wheel is threadedly connected to the titanium alloy rod. The winding reel is mounted on the base, and the drive wheel is rotatably mounted on the base.

2. The spinal column limiting mechanism of claim 1 wherein: The first fixing group, the second fixing group, and the third fixing group are arranged from front to back; The clamping plate includes a base, and the bottom of the base is provided with an inclined portion that slopes downward from back to front, and the inclined portion is provided with the mounting hole; The angle between the inclined portion of the clamping plate of the first fixing group and the base is smaller than the angle between the inclined portion of the clamping plate of the second fixing group and the base, and the angle between the inclined portion of the clamping plate of the second fixing group and the base is smaller than the angle between the inclined portion of the clamping plate of the third fixing group and the base.

3. The spinal column limiting mechanism of claim 2 wherein: The angle between the inclined portion of the clamping plate of the first fixing group and the base is 137°-138°; The angle between the inclined portion of the clamping plate of the second fixing group and the base is 142°-143°; The angle between the inclined portion of the clamping plate of the third fixing group and the base is 154°-155°.

4. The spinal column limiting mechanism of claim 1 wherein: When the spine of the experimental rats moved, the second fixed group swung, pulling the transmission wire, which drove the transmission wheel to rotate, and then drove the titanium alloy rod to move axially and insert into the intervertebral foramen.

5. The spinal column positioning mechanism of claim 1 wherein: The transmission wheel includes a transmission part and a bearing part arranged adjacent to each other in the axial direction. The transmission part is provided with the meshing teeth and a threaded hole for threaded connection to the titanium alloy rod. The bearing portion is rotatably connected to the base.

6. The spinal column positioning mechanism of claim 1 wherein: The length of the first fixed group is less than the length of the second fixed group and the length of the third fixed group; The length of the third fixed group is less than the length of the second fixed group.

7. The spinal restraint mechanism according to claim 1, characterized in that: The center distance between the circular hole and the adjustment hole of the first connecting plate is 7.3mm-7.5mm; The center distance between the circular hole and the adjustment hole of the second connecting plate is 7.3mm-7.5mm.

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