Artificial lamina and spinal fixation device

Abstract

The application discloses an artificial lamina, which comprises a lamina body and a lamina fixing device; at least two fixing holes are formed on both sides of the lamina body, and the fixing holes on the two sides are correspondingly arranged; an internal thread is arranged in the fixing hole; a receiving groove is formed at each corner of the lamina body; the lamina fixing device comprises a fixing block, a screw rod, a nut and a jackscrew, the fixing block is provided with a transverse through hole, a longitudinal hole formed on the upper surface and a groove capable of engaging with a titanium rod, the transverse through hole and the longitudinal hole are communicated, and internal threads are arranged in the transverse through hole and the longitudinal hole; an external thread on the screw rod is matched with the internal thread of the transverse through hole and can pass through the transverse through hole; an external thread of the jackscrew is matched with the internal thread of the longitudinal hole and can be screwed into the longitudinal hole; an external thread of the screw rod is matched with the internal thread of the nut and can pass through the nut; the external thread on the screw rod is matched with the internal thread of the fixing hole, and the screw rod passes through the corresponding fixing hole. The application further discloses a spinal internal fixation device comprising the artificial lamina.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to an artificial lamina and a spinal internal fixation device. BACKGROUND

[0002] Laminectomy is a common surgical procedure for some spinal degenerative diseases and part of the posterior column trauma. The symptoms of most patients can be relieved for a long time after the operation, but some patients have recurrent pain after the operation. One of the main reasons is the fibrosis around the dura mater and nerve root after the removal of the lamina. A large amount of scar tissue causes the dura mater and nerve root to adhere to the surrounding tissue, especially the dorsal sacrospinal muscle, which causes traction and compression of the nerve and makes the reoperation difficult. In recent years, artificial lamina has been used in posterior spinal surgery to prevent scar formation and maintain the stability of the posterior spine.

[0003] The existing lamina usually needs to be fixed by special screws or wires. For example, the artificial lamina of patent CN2880012Y and the artificial lamina for use after laminectomy of the spinal column of patent application CN201710483156.3 increase the complexity of the operation or cause unnecessary damage to the patient. Although the buckle fixing of patent CN107411854A avoids unnecessary damage to the patient caused by re-drilling and installation, the contact area is small and the fixation is not stable enough, and the buckle is easy to loosen from the titanium rod under stress. SUMMARY

[0004] The purpose of the present application is to provide an artificial lamina that can be easily fixed and stably connected with the existing nail rod system.

[0005] In one aspect of the present application, an artificial lamina is provided, comprising a lamina body and a lamina fixing device.

[0006] At least two fixing holes are formed on both sides of the lamina body, and the fixing holes on both sides are correspondingly arranged. An internal thread is arranged in the fixing hole. The fixing hole can be formed with multiple holes as needed, but the number of holes should not affect the firmness of the lamina body.

[0007] A receiving groove is formed at each corner of the lamina body.

[0008] The lamina fixing device comprises a fixing block, a screw rod, a nut and a jackscrew. The fixing block is provided with a transverse through hole, a longitudinal hole formed from the upper surface and a groove capable of engaging the titanium rod. The transverse through hole and the longitudinal hole are in communication, and both have an internal thread. Preferably, the inner diameter of the groove is the same as the diameter of the titanium rod in the nail rod system, so that the titanium rod can be firmly engaged.

[0009] The outer thread on the screw rod is matched with the inner thread of the transverse through hole, and can pass through the transverse through hole; the outer thread of the jack screw is matched with the inner thread of the longitudinal hole, and can be screwed into the longitudinal hole; the outer thread of the screw rod is matched with the inner thread of the nut, and can pass through the nut.

[0010] The outer thread on the screw rod is matched with the inner thread of the fixing hole, and the screw rod passes through the corresponding fixing hole.

[0011] Preferably, the lamina is an arch-shaped structure with a middle convex part. More preferably, the convex part has the same convex curvature as that of a normal human lamina.

[0012] Preferably, the corners of the lamina are all round-angled structures, which can reduce the weight of the vertebral body and avoid injury to surrounding tissues during implantation.

[0013] Preferably, the screw rod is further provided with a plurality of longitudinal fine grooves at one end, which can increase the friction when the screw rod is rotated.

[0014] Preferably, the accommodating groove can partially accommodate the head part of the pedicle screw.

[0015] More preferably, the accommodating groove has a shape suitable for the shape of the head of the pedicle screw.

[0016] Preferably, the two ends of the lamina body are provided with clamping grooves, and the clamping grooves at the two ends are correspondingly arranged, and the clamping grooves can be seamlessly spliced when the two lamina bodies are spliced.

[0017] Preferably, the lamina body is made of degradable material; preferably, natural biodegradable material is used; more preferably, artificial synthetic biodegradable material is used.

[0018] Another aspect of the present application also provides a spinal internal fixation device comprising the artificial lamina as described above.

[0019] Advantages

[0020] The present application discloses an artificial lamina, which comprises a lamina body and a lamina fixing device. The lamina body is provided with fixing holes on both sides, and the fixing holes are provided with inner threads. The outer thread on the screw rod of the lamina fixing device is matched with the inner thread of the transverse through hole in the fixing block, passes through the transverse through hole, and then passes through the fixing hole of the lamina body. The passing-in end is pressed and fixed in place by the jack screw screwed into the longitudinal hole of the fixing block, and the passing-out end of the lamina body is fixed by the nut. Meanwhile, the groove for engaging the titanium rod on the fixing block also engages the titanium rod. By tightening the nut, the engagement force is increased, and the lamina is also pressed to the side surface of the fixing block. As a result, the lamina fixing block and the nail-rod system are combined into an integrated whole, the stress is uniformly distributed on the entire nail-rod system and the lamina, and the stability and effectiveness of the three-dimensional fixation are ensured.

[0021] The lamina in the application is connected to the existing spinal fixation nail rod system through the lamina fixing device, the screw rod in the lamina fixing device realizes the function of the existing transverse connection in the spinal fixation nail rod system, the lamina body is firmly installed, the lamina installation step is simplified, the operation time is saved, and the harm to the patient caused by repeated fixation is avoided. The artificial lamina of the application also designs a clamping groove structure at both ends of the lamina body, so that when multiple laminae need to be connected and fixed, the laminae can be clamped and seamlessly connected with each other, preventing scar crawling or autologous bone graft fragments from falling into the spinal canal. The artificial lamina of the application also uses biodegradable materials, which can be absorbed and decomposed by the human body after being implanted in the human body for a period of time, thereby preventing the adverse effects of scar on the spine and not hindering the growth of new bone. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic view of the artificial lamina of the application;

[0023] Figure 2 It is a left view of the artificial lamina of the application;

[0024] Figure 3 It is a front view of the artificial lamina of the application;

[0025] Figure 4 It is a top view of the artificial lamina of the application;

[0026] Figure 5 It is a front view of the screw rod of the application;

[0027] Figure 6 It is a structural schematic view of the spinal internal fixation device of the application;

[0028] Figure 7 It is an exploded view of the spinal internal fixation device of the application;

[0029] Figure 8 It is a structural schematic view of the artificial lamina of embodiment 2 of the application;

[0030] Figure 9 It is a structural schematic view of the artificial lamina of embodiment 2 of the application in a spliced state.

[0031] The reference signs are as follows:

[0032] Lamina body 1, fixing hole 11, accommodating groove 12, clamping groove 13, lamina fixing device 2, fixing block 21, longitudinal hole 211, transverse through hole 212, recess 213, jackscrew 22, screw rod 23, longitudinal fine groove 231, nut 24, pedicle screw 3, titanium rod 4. DETAILED DESCRIPTION

[0033] The following examples are intended to illustrate the present application and are not intended to limit the scope of the present application. If not specifically stated, the technical means used in the examples are conventional means known to those skilled in the art.

[0034] Example 1

[0035] Referring to Figures 1 to 7 As shown in the drawings, the present embodiment provides an artificial lamina for use in conjunction with an internal fixation pin-rod system of a spinal column to fix a spinal column site where a lamina has been removed and to prevent scar tissue from adhering the dura mater and the nerve root to the surrounding tissue, particularly the dorsal sacrospinal muscle, and to pull and compress the nerve. It also facilitates secondary surgery.

[0036] The artificial lamina in the present embodiment comprises a lamina body 1 and a lamina fixing device 2. The lamina body 1 is an arched structure with a convex middle (the lamina body can also be a flat structure, which can block scar tissue). The curvature of the arch is the same as that of a normal human lamina. Preferably, the curvature can also be designed to be selectable in multiple curvatures as needed to adapt to the needs of different human bodies.

[0037] Two fixing holes 11 are formed on each side (the fixing holes can be formed in multiple numbers as needed, but the number should not affect the strength of the lamina body). The fixing holes 11 on the two sides are arranged in corresponding positions. The fixing holes 11 are internally threaded. The four corners of the lamina body 1 are provided with receiving grooves 12, which can be used to accommodate the head of a pedicle screw 3 when the lamina body 1 is fixed in a pin-rod system. The receiving grooves 12 in the present embodiment are square, and preferably can also be designed as semicircular grooves or arc-shaped grooves that are adapted to the head of the pedicle screw 3 to make the combination of the lamina body 1 and the pin-rod system more compact. The receiving grooves 12 can partially accommodate the head part of the pedicle screw 3.

[0038] The lamina fixation device 2 comprises a fixing block 21, a screw rod 23, a nut 24 and a jackscrew 22. The fixing block 21 is provided with a transverse through hole 212, a longitudinal hole 211 opened from the upper surface and a recess 213 capable of engaging the titanium rod 4. The transverse through hole 212 and the longitudinal hole 211 are communicated and both are provided with internal threads. The inner diameter of the recess 213 is the same as the diameter of the titanium rod 4 in the nail-rod system, so that the titanium rod 4 can be firmly engaged. The external thread of the screw rod 23 is matched with the internal thread of the transverse through hole 212, so that the screw rod 23 can pass through the transverse through hole 212. The external thread of the jackscrew 22 is matched with the internal thread of the longitudinal hole 211, so that the jackscrew 22 can be screwed into the longitudinal hole 211. The external thread of the screw rod 23 is matched with the internal thread of the nut 24, so that the screw rod 23 can pass through the nut 24. The external thread of the screw rod 23 is matched with the internal thread of the fixing hole 11, so that the screw rod 23 passes through the corresponding fixing hole 11. After the screw rod 23 passes through the transverse through hole 212, it passes through the fixing hole 11 of the lamina body 1. The passing-in end is pressed down to the fixed position by the jackscrew 22 screwed into the longitudinal hole 211 of the fixing block 21. The passing-out end of the lamina body 1 is fixed by the nut 24. At the same time, the recess 213 capable of engaging the rod opened on the fixing block 21 also engages the titanium rod 4. By tightening the nut 24, the engagement force is increased, and at the same time, the lamina body 1 is pressed to the side surface of the fixing block 21, so that the lamina body 1, the fixing block 21 and the nail-rod system are combined into one.

[0039] In the embodiment, the screw rod 23 is further provided with a plurality of longitudinal fine grooves 231 at one end, which can increase the friction when the screw rod 23 is rotated, and facilitate the user to operate when installing the screw rod 23.

[0040] The lamina body 1 is made of degradable materials, which can be natural biological degradable materials or artificially synthesized biological degradable materials. The natural biological degradable materials include chitin, chitosan, fibrin, collagen and cellulose derivatives, etc. The artificially synthesized biological degradable materials include polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxybutyrate, poly anhydride or copolymer thereof. In the embodiment, the artificially synthesized biological degradable materials are used.

[0041] In use, take the total lamina spinal canal exposure way of lumbar internal fixation surgery as an example, cut off the spinous process at the root with a spinous process scissors, cut off the interlamina ligament with a sharp knife, and remove the lamina with a rongeur to expose the dura mater and nerve roots of the thoracolumbar segment. Push the dura mater and nerve roots to one side with a nerve stripper to expose the posterior longitudinal ligament, vertebral body and posterior intervertebral disc, determine the entry point of the pedicle screw 3, remove the articular process, and use a pathfinder to attack the pedicle screw 3 into the vertebral body through the bilateral pedicle. Place the titanium rod 4, press the titanium rod 4 in the head of the pedicle screw 3 by fixing the top wire 22 of the pedicle screw 3, fix the artificial lamina body 1 at the lamina defect, hold the screw rod 23 with a longitudinal slot at one end, pass the other end through the fixing hole 11 of the lamina body 1, rotate in the threaded direction, pass out of the fixing hole 11, and fix the passing end with the nut 24. The passing end is pressed down to the fixed position by the top wire 22 screwed into the longitudinal hole 211 of the fixing block 21, the passing end of the lamina body 1 is fixed with the nut 24, and the groove 213 for clamping the rod on the fixing block 21 clamps the titanium rod 4. Adjust the tightness of the lamina body 1 by tightening the nut 24, increase the clamping force, and press the lamina body 1 to the side of the fixing block. Then, rinse the wound with a large amount of normal saline, place a drainage tube after hemostasis, and suture layer by layer.

[0042] The artificial lamina of the present embodiment fixes the lamina body 1 in the existing nail rod system through the lamina fixing device 2, so that the artificial lamina can be combined with the existing spinal fixation nail rod system. The screw rod 23, nut 24 and fixing block 21 in the fixing device are used for fixation, so that the lamina is easy to install and the harm to the patient caused by repeated fixation is avoided. The lamina of the present embodiment also uses artificial synthetic biodegradable materials. Compared with natural biodegradable materials, the microstructure, mechanical energy, shape and degradation time of artificial synthetic biodegradable materials can be pre-set during production, so that they can be completely degraded in the human body without affecting new bone formation, and can be mass-produced according to standards.

[0043] Embodiment 2

[0044] Referring to Figure 8 and Figure 9 The artificial lamina in the present embodiment includes a lamina body 1 and a lamina fixing device 2. The lamina body 1 is an arched structure with a middle protrusion, and the curvature of the arch is the same as that of the normal lamina of the human body.

[0045] Two fixing holes 11 are arranged on both sides, and the fixing holes 11 on both sides are arranged in corresponding positions; the fixing holes 11 are internally provided with internal threads. The four corners of the lamina body 1 are respectively provided with accommodating grooves 12, which can be used to accommodate the screw caps of the pedicle screws 3 when the lamina is fixed into the nail-rod system. In the embodiment, the accommodating grooves 12 are square, and preferably, can also be designed into semicircular grooves or arc grooves which are adapted to the screw caps of the pedicle screws 3, so that the combination of the lamina body and the nail-rod system is more compact. The accommodating grooves 12 can partially accommodate the screw cap portions of the pedicle screws 3. Preferably, the corners of the lamina body 1 are all round corner structures (not shown in the figure). The round corner structures can reduce the weight of the vertebral body and can also avoid the surrounding tissues from being injured during implantation.

[0046] The lamina fixing device 2 comprises a fixing block 21, a screw rod 23, a nut 24 and a jackscrew 22. The fixing block 21 is provided with a transverse through hole 212, a longitudinal hole 211 which is arranged on the upper surface and a groove 213 which can engage with the rod. The transverse through hole 212 and the longitudinal hole 211 are communicated, and both are internally provided with internal threads. The inner diameter of the groove 213 is the same as the diameter of the titanium rod 4 in the nail-rod system, and the groove 213 can tightly engage with the titanium rod 4. The external threads on the screw rod 23 are matched with the internal threads of the transverse through hole 212, and the screw rod 23 can pass through the transverse through hole 212. The external threads of the jackscrew 22 are matched with the internal threads of the longitudinal hole 211, and the jackscrew 22 can be screwed into the longitudinal hole 211. The external threads of the screw rod 23 are matched with the internal threads of the nut 24, and the screw rod 23 can pass through the nut 24. The external threads on the screw rod 23 are matched with the internal threads of the fixing hole 11, and the screw rod 23 passes through the corresponding fixing hole 11. After the screw rod 23 passes through the transverse through hole 212 and then passes through the fixing hole 11 of the lamina body 1, the penetrating end is pressed and fixed downward by the jackscrew 22 which is screwed into the longitudinal hole 211 of the fixing block 21, and the penetrating end which penetrates out of the lamina body 1 is fixed by the nut 24. At the same time, the groove 213 which is arranged on the fixing block 21 and can engage with the rod also engages with the titanium rod 4. By tightening the nut 24, the engagement force is increased, and at the same time, the lamina body 1 is pressed tightly to the side surface of the fixing block 21, so that the lamina body 1, the fixing block 21 and the nail-rod system are combined into an integrated whole.

[0047] In the embodiment, the lamina body 1 is further provided with clamping grooves 13 at both ends, and the clamping grooves 13 at both ends are arranged in staggered positions (for example, the clamping groove at one end is arranged in the upper half, and the clamping groove at the opposite end is arranged in the lower half). When multiple artificial laminae need to be connected and fixed, the lamina bodies 1 can be clamped and seamlessly connected with each other, so as to prevent the scar from entering or the autograft fragments from falling into the spinal canal.

[0048] The edge portion of the lamina body 1 is designed as a round corner structure as far as possible without affecting the seamless splicing (not shown in the figure).

[0049] The use method and advantages of the artificial lamina in the embodiment are the same as those in the embodiment 1, and the artificial lamina in the embodiment is designed as a round corner structure, so that the surrounding tissues can be prevented from being injured during installation.

[0050] Embodiment 3

[0051] Embodiment 3 provides a spinal internal fixation device, which comprises a nail-rod system and an artificial lamina. Figure 6 and Figure 7 This embodiment comprises the artificial lamina as described in Embodiment 1, and the technical features of the artificial lamina disclosed in Embodiment 1 are also applicable to this embodiment. The technical features of the artificial lamina disclosed in Embodiment 1 are not repeated here.

[0052] The spinal internal fixation device provided in this embodiment comprises a nail-rod system and an artificial lamina.

[0053] The nail-rod system and the artificial lamina are fixed on the titanium rod 4 through the lamina fixing device 2 of the artificial lamina. This spinal internal fixation device simplifies the installation steps of the artificial lamina, reduces the excessive damage to the patient's vertebral body, improves the firmness of the lamina installation, and increases the stability of the spinal internal fixation system.

[0054] Although the present application has been described in detail with general description and specific embodiments above, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application are within the scope of the present application.

Claims

1. An artificial vertebral plate, characterized in that: It includes a lamina body and a lamina fixation device; At least two fixing holes are provided on both sides of the lamina body, and the fixing holes on both sides are provided correspondingly; internal threads are provided in the fixing holes; and accommodating grooves are provided at the four corners of the lamina body; The vertebral plate fixation device includes a fixing block, a screw, a nut and a top screw. The fixing block is provided with a transverse through hole, a longitudinal hole opened from the upper surface and a groove capable of engaging with a titanium rod. The transverse through hole and the longitudinal hole are connected and are internally provided with internal threads. The external thread on the screw matches the internal thread of the transverse through hole and can pass through the transverse through hole. The external thread of the top screw matches the internal thread of the longitudinal hole and can be screwed into the longitudinal hole. The external thread of the screw matches the internal thread of the nut and can pass through the nut. The external thread on the screw rod matches the internal thread of the fixing hole, and the screw rod passes through the corresponding fixing hole; The vertebral plate is an arched structure with a convex middle; The screw rod passes through the transverse through hole of the fixing block and then passes through the fixing hole of the vertebral plate body. The inserted end is pressed downward and fixed in position by screwing into the top screw in the longitudinal hole of the fixing block. The exit end passing through the vertebral plate body is fixed by a nut. At the same time, the groove for biting the rod on the fixing block also bites the titanium rod. By tightening the nut to increase the biting force, the vertebral plate body is pressed against the side of the fixing block, so that the vertebral plate body, the fixing block and the nail-rod system are integrated into one. The vertebral plate fixing device is respectively connected to the vertebral plate body and the two sides of the nail rod system in a central symmetrical manner, so that the stress is evenly distributed throughout the nail rod system and the vertebral plate.

2. The artificial vertebral plate according to claim 1, wherein: The edges and corners of the vertebral plate are all rounded structures.

3. The artificial vertebral plate according to claim 1, wherein: One end of the screw rod is also provided with a plurality of longitudinal slots.

4. The artificial vertebral plate according to claim 1, wherein: The receiving groove can partially receive the screw head portion of the pedicle screw.

5. The artificial vertebral plate according to claim 1, wherein: The shape of the accommodating groove is adapted to the shape of the pedicle screw head.

6. The artificial vertebral plate according to claim 1, wherein: The two ends of the vertebral plate body are provided with clamping grooves, which are arranged correspondingly. When two vertebral plate bodies are spliced ​​together, the clamping grooves can be seamlessly spliced.

7. The artificial vertebral plate according to claim 1, wherein: The lamina body is made of biodegradable material.

8. A spinal internal fixation device, characterized in that: The method comprises the artificial vertebral plate according to any one of claims 1 to 7.

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