Minimally invasive degradable reduction device for thoracolumbar vertebral fracture

Abstract

The invention discloses a minimally invasive degradable reduction device for thoracolumbar vertebral fracture, and relates to the technical field of medical instruments. The mounting mechanism is mounted on the outer wall of the connecting rod in a sleeving manner; the pedicle screw is movably inserted into the middle of the top end of the mounting mechanism; an implantation mechanism; through cooperative work of the connecting rod, the mounting mechanism, the pedicle screw and the connecting mechanism, the whole reduction device adapts to minimally invasive approach modes such as percutaneous puncture and can be implanted into the body of a patient through a percutaneous puncture channel, a skin incision of the minimally invasive approach is small, damage to surrounding tissue is greatly reduced, and the reduction effect is good. Due to the layered design of the screw body in the pedicle screw, bone tissue ingrowth is promoted while the supporting strength is kept, and the reduction device is made of degradable materials, can be gradually degraded along with fracture healing after an operation and is metabolized and absorbed by an organism, and does not need to be taken out through a secondary operation, so that physical and mental pain of a patient is relieved; and the medical cost and the potential risk of the secondary operation are also reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a thoracolumbar fracture minimally invasive degradable reduction device. BACKGROUND

[0002] Thoracolumbar fracture refers to the fracture of the spinal column occurring in the thoracic and lumbar segments. This part is the connecting area of the thoracic and lumbar segments of the spinal column, which supports the thoracic bone and transmits the weight of the lumbar vertebrae. It is not only the concentration point of the mechanical stress of the spinal column, but also one of the most common sites of clinical spinal fractures. The causes of the disease are mainly divided into two types: traumatic and pathological. Traumatic factors are mainly direct or indirect violent impact such as falling from a high place, being hit by a heavy object, and traffic accidents. Pathological factors are often caused by bone destruction of the vertebral body due to diseases such as osteoporosis, spinal tumors, and tuberculosis. A slight external force can cause a fracture. For the minimally invasive treatment needs of such fractures, special medical devices are used to achieve fracture reduction and fixation. The reduction device is a core instrument unit designed for thoracolumbar fracture minimally invasive treatment, which has the functions of fracture end alignment correction and temporary fixation and can achieve in vivo biodegradation.

[0003] In the Chinese patent with publication number CN204033455U, a thoracolumbar fracture, slippage anatomical type of spinal column reduction fixator is disclosed. The anatomical type of spinal column reduction fixator is specially used for open surgery treatment of severe thoracolumbar compression, burst fracture, and lumbar spinal stenosis, lumbar instability / slippage. It is suitable for thoracolumbar fracture injured vertebral body compression collapse more than 1 / 3 of the vertebral body height and burst fracture with spinal cord and nerve compression symptoms. It is also suitable for old thoracolumbar fracture without regular treatment with kyphosis deformity, lumbar disc herniation, and spinal stenosis with lumbar instability / slippage.

[0004] The existing reduction device needs a large surgical channel or extensive dissection of the paravertebral muscle, which often has the disadvantages of large trauma, excessive bleeding, and slow postoperative recovery of the patient. At the same time, the in vivo fixation of such devices is mostly made of non-degradable materials, which requires a second surgery to remove it after the operation, which not only increases the physical and mental pain of the patient, but also increases the overall medical cost and potential risk of the second surgery. SUMMARY

[0005] The purpose of the present application is to provide a thoracolumbar fracture minimally invasive degradable reduction device to solve the problems of large trauma and the need for secondary surgery to remove the fixation of the existing reduction device.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: a thoracolumbar fracture minimally invasive degradable reduction device, comprising a connecting rod;

[0007] A mounting mechanism is sleeved and mounted on the outer wall of the connecting rod;

[0008] A pedicle screw movably inserted into the middle of the top end of the mounting mechanism;

[0009] An implanting mechanism movably inserted into the middle of the top end of the pedicle screw;

[0010] A connecting mechanism movably mounted on both ends of the connecting rod;

[0011] The connecting rod, the mounting mechanism, the pedicle screw and the connecting mechanism are all provided with a plurality of the pedicle screws corresponding to the distribution of the pedicle positions of the upper and lower vertebral bodies of the injured vertebrae;

[0012] The pedicle screw comprises a screw body, a reinforcing leaf and a screw ball head, the reinforcing leaf is arranged at the lower part of the outer wall of the screw body, the screw ball head is arranged at the top end of the screw body, and the screw ball head is connected with the mounting mechanism;

[0013] The screw body comprises a core layer, a transition layer, a surface layer and a delayed degradation coating, the transition layer is arranged on the outer wall of the core layer, the surface layer is arranged on the outer wall of the transition layer, and the delayed degradation coating is coated on the outer wall of the surface layer.

[0014] Further, the pedicle screw further comprises a plurality of expansion grooves, a positioning clamping groove, an expansion screw and a limiting clamping groove, the plurality of expansion grooves are all arranged on the lower side of the outer wall of the screw body, the positioning clamping groove is arranged in the middle of the top end of the screw ball head, the expansion screw is screw-mounted in the interior of the screw body, and the limiting clamping groove is arranged in the middle of the top end of the expansion screw.

[0015] Further, the implanting mechanism comprises an implanting cylinder, a positioning clamping block, a rotating ring, an implanting rod, a limiting clamping block and a rotating handle, the positioning clamping block is mounted on the bottom end of the implanting cylinder, the rotating ring is mounted on the upper side of the outer wall of the implanting cylinder, the implanting rod is movably inserted into the interior of the implanting cylinder, the limiting clamping block is mounted on the bottom end of the implanting rod, and the rotating handle is mounted on the top end of the implanting rod.

[0016] Further, the mounting mechanism comprises a mounting seat, a plurality of mounting grooves, a cushion block, a mounting block and an adjusting groove, the mounting seat is sleeved on the outer surface of the connecting rod, the plurality of mounting grooves are respectively arranged on the inner walls of both sides of the mounting seat, the cushion block is placed in the middle of the bottom inner wall of the mounting seat, the mounting block is screw-mounted between the inner walls of both sides of the mounting seat, and the adjusting groove is arranged in the middle of the top end of the mounting block.

[0017] Further, the connecting mechanism comprises a connecting sleeve, two locking bolts, a connecting groove, a universal ball head, a locking sleeve and a locking groove, the connecting sleeve is installed at one end of the connecting rod, the two locking bolts are respectively embeddedly installed at the two side outer walls of the connecting sleeve, the connecting groove is opened at the right side of the outer wall of the connecting sleeve, the universal ball head is installed at the other end of the connecting rod and is clamped with the connecting sleeve, the locking sleeve is sleeved on the outer surface of the universal ball head, and the locking groove is opened at the left side of the inner wall of the locking sleeve.

[0018] Further, the connecting rod, the mounting mechanism, the pedicle screw and the connecting mechanism are all made of PLGA, polylactic acid or magnesium alloy material, the surfaces of the connecting rod, the mounting mechanism and the connecting mechanism are all coated with a coating layer which is consistent with the delayed degradation coating material of the screw body, the core layer is provided as a high-strength dense matrix, the porosity gradient of the transition layer increases from inside to outside, and the grain size of the transition layer is correspondingly refined, and the surface layer is provided as a nano-scale porous structure.

[0019] Further, the positioning clamping groove and the limiting clamping groove are both provided as regular hexagonal structures, the screw body is designed as a hollow structure, the inner lower side of the hollow cavity of the screw body and the lower part of the outer surface of the expansion screw are both provided as conical structures, and the reinforcing leaves are provided as spiral structures.

[0020] Further, the positioning clamping block and the limiting clamping block are both provided as regular hexagonal structures, the positioning clamping block is clamped with the positioning clamping groove, the limiting clamping block is clamped with the limiting clamping groove, and the lower part of the outer surface of the limiting clamping block is provided as a hexagonal pyramid structure.

[0021] Further, U-shaped notches are opened at the other two side inner walls of the mounting seat, an arc-shaped groove is opened at the top middle part of the pad, and the outer wall of the mounting block is provided with a spiral strip matched with the mounting groove.

[0022] Further, recesses matched with the universal ball head are arranged in the interiors of the connecting sleeve and the locking sleeve, the locking sleeve is threadedly connected with the connecting groove on the connecting sleeve through the locking groove, and a plurality of anti-skid grooves are opened at the outer wall of the locking sleeve.

[0023] Compared with the prior art, the beneficial effects of the present application are:

[0024] (1) The present application is through the cooperation of the connecting rod, the mounting mechanism, the pedicle screw and the connecting mechanism, the whole reset device is suitable for minimally invasive access such as percutaneous puncture, can be implanted into the patient's body through the percutaneous puncture channel, the skin incision of minimally invasive access is small, greatly reducing the damage to the surrounding tissue, and the layered design of the screw body in the pedicle screw promotes bone tissue ingrowth while maintaining support strength, and the reset device is made of degradable material, which can be gradually degraded and metabolized by the body after fracture healing, without the need for secondary surgery to remove, which not only reduces the physical and mental pain of the patient, but also reduces the medical cost and potential risk of secondary surgery.

[0025] (2) The present application is through the cooperation of the pedicle screw and the implanting mechanism, the positioning block is first clamped with the positioning slot, the screw body can be implanted by rotating the rotating ring, then the limiting block is clamped with the limiting slot, the expansion screw can be driven to move downward by rotating the rotating handle, the expansion slot on the screw body is extruded by the expansion screw, the radial expansion of the lower end of the screw body is realized, the occlusal force with the pedicle bone is further enhanced by the reinforcing leaf, and the anchoring firmness of the pedicle screw in the vertebral body is improved.

[0026] (3) The present application is through the cooperation of the mounting mechanism and the connecting mechanism, the flexible assembly and accurate fitting of the reset device are realized, the pedicle screw is clamped and fixed on the mounting seat, the connecting rod is also placed on the pad, then the connecting rod and the pedicle screw are installed on the mounting seat by rotating the mounting block, the installation adaptability is improved, the angle between the two connecting rods can be freely adjusted through the universal ball head, at the same time, the two connecting rods can be disassembled through the connecting sleeve and the locking sleeve, which is convenient for replacing the connecting rod according to the physiological curvature of the patient's vertebrae, and the adaptability of the reset device to different patient's anatomical structures is improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments, and obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0028] Figure 1 The overall structure schematic diagram provided by the embodiment of the present application is provided.

[0029] Figure 2 The connection diagram one of the pedicle screw and the implanting mechanism provided by the embodiment of the present application is provided.

[0030] Figure 3 The connection diagram two of the pedicle screw and the implanting mechanism provided by the embodiment of the present application is provided.

[0031] Figure 4A structural sectional view of the pedicle screw is provided for the embodiment of the present application.

[0032] Figure 5 A structural layered view of the screw body is provided for the embodiment of the present application.

[0033] Figure 6 A structural exploded view of the mounting mechanism is provided for the embodiment of the present application.

[0034] Figure 7 A structural exploded view of the connecting mechanism is provided for the embodiment of the present application.

[0035] Figure 8 A structural schematic view of the implanting mechanism is provided for the embodiment of the present application.

[0036] Legend of reference signs:

[0037] 1, connecting rod; 2, mounting mechanism; 3, pedicle screw; 4, connecting mechanism; 5, implanting mechanism; 21, mounting seat; 22, mounting groove; 23, cushion block; 24, mounting block; 25, adjusting groove; 31, screw body; 32, reinforcing leaf; 33, expansion groove; 34, screw ball head; 35, positioning clamping groove; 36, expansion screw; 37, limiting clamping groove; 311, core layer; 312, transition layer; 313, surface layer; 314, delayed degradation coating; 41, connecting sleeve; 42, locking bolt; 43, connecting groove; 44, universal ball head; 45, locking sleeve; 46, locking groove; 51, implanting cylinder; 52, positioning clamping block; 53, rotating ring; 54, implanting rod; 55, limiting clamping block; 56, rotating handle. DETAILED DESCRIPTION

[0038] In order for those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below in conjunction with the drawings.

[0039] As shown in the accompanying Figure 1 to the accompanying Figure 8 drawings:

[0040] Example one:

[0041] The present application provides a minimally invasive degradable reduction device for thoracolumbar fracture, which comprises a connecting rod 1, which undertakes the important task of connecting various key components and transmitting mechanical signals, and ensures that the physiological curvature and mechanical balance of the spine can be stably maintained during the operation process and the postoperative recovery stage;

[0042] The mounting mechanism 2 is sleeved and mounted on the outer wall of the connecting rod 1;

[0043] The pedicle screw 3 is movably inserted into the top middle part of the mounting mechanism 2, and is the key mechanical fixing point of the entire reduction device;

[0044] The implanting mechanism 5 is inserted into the middle part of the top end of the pedicle screw 3, and can accurately implant the pedicle screw 3 into the predetermined pedicle position;

[0045] The connecting mechanism 4 is detachably installed at both ends of the connecting rod 1, and during the operation, the doctor can flexibly adjust the connecting mechanism 4 according to the specific situation of the patient to achieve the best reduction effect;

[0046] The connecting rod 1, the installing mechanism 2, the pedicle screw 3 and the connecting mechanism 4 are all provided with multiple ones, and the multiple pedicle screws 3 are distributed corresponding to the pedicle positions of the upper and lower vertebral bodies of the injured vertebrae, so as to ensure the all-round and multi-angle fixation and reduction of the fractured vertebral body;

[0047] The pedicle screw 3 comprises a screw body 31, a reinforcing leaf 32 and a screw ball head 34, the reinforcing leaf 32 is arranged at the lower part of the outer wall of the screw body 31, and can increase the friction between the screw and the vertebral bone tissue, and improve the stability of the fixation, and the screw ball head 34 is arranged at the top end of the screw body 31, and the screw ball head 34 is connected with the installing mechanism 2;

[0048] The screw body 31 comprises a core layer 311, a transition layer 312, a surface layer 313 and a delayed degradation coating layer 314, the transition layer 312 is arranged at the outer wall of the core layer 311, the surface layer 313 is arranged at the outer wall of the transition layer 312, and the delayed degradation coating layer 314 is coated on the outer wall of the surface layer 313;

[0049] The connecting rod 1, the mounting mechanism 2, the pedicle screw 3 and the connecting mechanism 4 are all made of PLGA, polylactic acid or magnesium alloy material, which has good biocompatibility and degradability, can be gradually degraded and absorbed in the human body, avoids the pain and risk of secondary surgery removal, and the PLGA material is suitable for middle-aged and elderly patients with thoracolumbar compression fractures and mild burst fractures; the polylactic acid material is suitable for young patients with simple thoracolumbar fractures (without serious mechanical load requirements) and patients with limited economic conditions; the magnesium alloy material is suitable for young and middle-aged patients with thoracolumbar burst fractures and severe vertebral instability requiring strong mechanical support, and the surfaces of the connecting rod 1, the mounting mechanism 2 and the connecting mechanism 4 are coated with a coating layer consistent with the material of the delayed degradation coating layer 314 of the screw body 31, which further delays the degradation rate of the device, ensures that the device can provide sufficient support force in the early stage of fracture healing, the core layer 311 is set as a high-strength dense matrix, which provides a solid mechanical support for the pedicle screw 3 and ensures that it can withstand a large mechanical load during implantation and fixation, the porosity of the transition layer 312 increases from inside to outside, and the grain size of the transition layer 312 is correspondingly refined, this unique design makes the transition layer 312 achieve a good balance between mechanical properties and biocompatibility, which can ensure the strength of the screw and is also conducive to the growth and fusion of bone tissue, the surface layer 313 is set as a nano-scale porous structure, which further improves the bonding force between the screw and the bone tissue and promotes the rapid growth and healing of the bone tissue.

[0050] Working principle: First, install the pedicle screw 3 on the installation mechanism 2, and then according to the anatomical position of the pedicle of the upper and lower vertebral bodies of the injured vertebra, the multiple pedicle screws 3 are implanted into the corresponding pedicle of the vertebral body through the percutaneous puncture channel one by one, wherein the spiral reinforcing leaf 32 designed on the lower part of the outer wall of the screw body 31 can effectively enhance the occlusion force between the screw and the bone, ensure the stability of the implant, at the same time, the core layer 311 of the screw body 31 can bear the initial fixed load and provide stable and reliable support for the injured vertebra, then the connecting rod 1 is implanted across the injured vertebra through the same percutaneous puncture channel and adjusted to the position that fits the physiological curvature of the spine, and accurately placed in the installation mechanism 2, the preliminary stable fixation of the connecting rod 1 and the pedicle screw 3 is realized through the installation mechanism 2, which ensures the stability of the connection and prevents the displacement of the components, then the multiple connecting rods 1 are firmly connected together by the connecting mechanism 4, further expanding the fixed range and significantly improving the overall support effect of the device on the spine, the whole reduction device is designed for minimally invasive approaches such as percutaneous puncture, all components can be implanted into the patient's body through a small skin incision, greatly reducing the damage to the surrounding tissues, the layered design of the screw body 31 in the pedicle screw 3 maintains high strength support while effectively promoting bone tissue ingrowth, the connecting rod 1, the installation mechanism 2, the pedicle screw 3 and the connecting mechanism 4 are all made of high-quality degradable materials such as PLGA, polylactic acid or magnesium alloy, and the surface coating is made of the same material as the delayed degradation coating 314 of the screw body 31, ensuring the synchronization of the degradation period, during the postoperative bone healing process, the transition layer 312 of the screw body 31 has a clever design of increasing porosity from inside to outside and refining the grain size gradient, which realizes the smooth transition of the elastic modulus from the core layer 311 to the surface layer 313, effectively reduces the stress shielding problem and avoids bone loss, the nano-scale porous structure of the surface layer 313 greatly promotes cell adhesion and bone tissue ingrowth, accelerates the bone healing process, and the delayed degradation coating 314 ensures that the device maintains sufficient strength during the early stage of bone healing, the degradable material gradually transfers the mechanical strength to the healing vertebra during the in vivo degradation process, avoiding stress shielding, and has excellent biocompatibility, significantly preventing the occurrence of foreign body-related complications, at the same time, the degradable material has good osteoconductivity, which can effectively promote new bone ingrowth and improve the quality of fracture healing, and the degradation product is non-toxic and fully meets the physiological metabolic needs of the human body, after the fracture is completely healed, the components will be gradually degraded and absorbed by the body metabolism, without the need for secondary surgery to remove them, which greatly reduces the physical and mental pain of the patient, significantly reduces the medical cost and potential risk of secondary surgery, at the same time, the device is suitable for minimally invasive approaches such as percutaneous puncture, effectively reducing the dissection and tissue damage of the paravertebral muscles during surgery, reducing the risk of postoperative infection and pain, and significantly improving the clinical application effect of minimally invasive treatment of thoracolumbar fractures.

[0051] Example two:

[0052] The embodiment is basically the same as the previous embodiment, and the difference is that the pedicle screw 3 further comprises a plurality of expansion grooves 33, a positioning clamping groove 35, an expansion screw 36 and a limiting clamping groove 37. The plurality of expansion grooves 33 are all arranged on the lower side of the outer wall of the screw body 31. The positioning clamping groove 35 is arranged in the middle of the top end of the screw ball 34. The expansion screw 36 is screw-mounted in the interior of the screw body 31. The limiting clamping groove 37 is arranged in the middle of the top end of the expansion screw 36.

[0053] The implanting mechanism 5 comprises an implanting cylinder 51, a positioning clamping block 52, a rotating ring 53, an implanting rod 54, a limiting clamping block 55 and a rotating handle 56. The positioning clamping block 52 is mounted at the bottom end of the implanting cylinder 51. The rotating ring 53 is mounted on the upper side of the outer wall of the implanting cylinder 51. The implanting rod 54 is movably inserted into the interior of the implanting cylinder 51. The limiting clamping block 55 is mounted at the bottom end of the implanting rod 54. The rotating handle 56 is mounted at the top end of the implanting rod 54.

[0054] The positioning clamping groove 35 and the limiting clamping groove 37 are both arranged in a regular hexagonal structure, which has high positioning accuracy and stability, can ensure the accurate clamping and stable connection between the implanting mechanism 5 and the pedicle screw 3, the screw body 31 is designed in a hollow structure, and the interior lower side of the hollow cavity of the screw body 31 and the lower part of the outer surface of the expansion screw 36 are both arranged in a conical structure. When the expansion screw 36 is rotated, the conical structure can make the screw body 31 uniformly expand at the expansion groove 33, increase the fixing force between the screw and the vertebral body, and the reinforcing leaf 32 is arranged in a spiral structure, which can increase the friction force between the screw and the vertebral bone tissue, improve the stability of the fixation, and is also beneficial to the growth and climbing of the bone tissue.

[0055] The positioning clamping block 52 and the limiting clamping block 55 are both arranged in a regular hexagonal structure, which matches the regular hexagonal structure of the positioning clamping groove 35 and the limiting clamping groove 37, ensures the accurate clamping and stable connection between the implanting mechanism 5 and the pedicle screw 3, the positioning clamping block 52 is clamped with the positioning clamping groove 35, which can realize the implantation of the pedicle screw 3, the limiting clamping block 55 is clamped with the limiting clamping groove 37, and the lower part of the outer surface of the limiting clamping block 55 is arranged in a hexagonal pyramid structure, which can further increase the clamping stability between the limiting clamping block 55 and the limiting clamping groove 37, and prevent the limiting clamping block 55 from being pulled out of the limiting clamping groove 37 during the rotation of the expansion screw 36.

[0056] Working principle: during operation, first, according to the position of the upper and lower vertebral body pedicle of the injured vertebra, the pedicle screw 3 is implanted through the percutaneous puncture channel, then the positioning block 52 of the implanting mechanism 5 is accurately inserted into the positioning slot 35 at the top of the screw ball head 34 of the pedicle screw 3, then the rotating ring 53 on the outer wall of the implanting cylinder 51 is rotated, driving the implanting cylinder 51 and the internal pedicle screw 3 to rotate synchronously, thereby the pedicle screw 3 is initially implanted into the patient's body, at this time, the spiral reinforcing leaf 32 on the lower side of the outer wall of the pedicle screw 3 plays a role, effectively enhancing the initial occlusion with the bone, then the implanting rod 54 is pushed to move downward along the inside of the implanting cylinder 51 until the limiting block 55 at the bottom of the implanting rod 54 is firmly clamped with the limiting slot 37 at the top of the expansion screw 36, at this time, the rotating handle 56 at the top of the implanting rod 54 is rotated, which can drive the implanting rod 54 and the expansion screw 36 threaded with it to rotate synchronously, since the expansion screw 36 is threaded with the screw body 31, and the lower side of the hollow cavity inside the screw body 31 and the lower part of the outer surface of the expansion screw 36 are designed as a conical structure, when the expansion screw 36 rotates and moves downward, the conical lower part will extrude the conical inner wall of the hollow cavity of the screw body 31, forcing the multiple expansion slots 33 on the lower side of the outer wall of the screw body 31 to open, making the lower end of the screw body 31 radially expand, further tightly occluding the pedicle bone, this design greatly improves the anchoring firmness of the pedicle screw 3 in the vertebral body, effectively avoids the problem of reduction failure caused by screw loosening and displacement after operation, provides reliable guarantee for long-term stability after fracture reduction, while ensuring minimally invasive and biodegradable, successfully solves the problem of easy loosening of traditional screws, and creates a more stable mechanical environment for fracture healing.

[0057] Embodiment three

[0058] This embodiment is basically the same as the previous embodiment, the difference is that the mounting mechanism 2 includes a mounting seat 21, a plurality of mounting grooves 22, a pad 23, a mounting block 24 and an adjusting groove 25, the mounting seat 21 is sleeved on the outer surface of the connecting rod 1, the plurality of mounting grooves 22 are respectively arranged on the inner walls of the two sides of the mounting seat 21, the pad 23 is placed in the middle of the bottom inner wall of the mounting seat 21, the mounting block 24 is threadedly mounted between the inner walls of the two sides of the mounting seat 21, and the adjusting groove 25 is arranged in the middle of the top of the mounting block 24.

[0059] The connecting mechanism 4 includes a connecting sleeve 41, two locking bolts 42, a connecting groove 43, a universal ball head 44, a locking sleeve 45 and a locking groove 46, the connecting sleeve 41 is mounted on one end of the connecting rod 1, the two locking bolts 42 are respectively embeddedly mounted on the outer walls of the two sides of the connecting sleeve 41, the connecting groove 43 is arranged on the right outer wall of the connecting sleeve 41, the universal ball head 44 is mounted on the other end of the connecting rod 1, and the universal ball head 44 is clamped with the connecting sleeve 41, the locking sleeve 45 is sleeved on the outer surface of the universal ball head 44, and the locking groove 46 is arranged on the left inner wall of the locking sleeve 45.

[0060] The inner walls on both sides of the mounting base 21 are provided with U-shaped notches, which facilitates the installation and adjustment of the connecting rod 1. The top center of the pad 23 is provided with an arc-shaped groove, which can better fit the outer surface of the connecting rod 1, increase the stability of the installation, and reduce the relative sliding between the connecting rod 1 and the mounting base 21. The outer wall of the mounting block 24 is provided with a spiral strip that matches the mounting groove 22. Through the cooperation of the spiral strip and the mounting groove 22, the mounting block 24 is threadedly installed in the mounting base 21.

[0061] The connecting sleeve 41 and the locking sleeve 45 have grooves inside that match the universal ball head 44, ensuring that the universal ball head 44 can rotate flexibly within the connecting sleeve 41 and the locking sleeve 45 to adapt to different spinal physiological curvatures and repositioning requirements. The locking sleeve 45 is threadedly connected to the connecting groove 43 on the connecting sleeve 41 through the locking groove 46. This threaded connection method has high connection strength and stability, ensuring a firm connection at both ends of the connecting rod 1. The outer wall of the locking sleeve 45 has multiple anti-slip grooves, which increase the friction when the doctor rotates the locking sleeve 45, making operation easier and improving surgical efficiency.

[0062] Working principle: during operation, first, the cushion block 23 and the mounting block 24 are taken out of the mounting seat 21, then the pedicle screw 3 is precisely inserted into the mounting seat 21, after the implantation and expansion of the pedicle screw 3 are completed, the cushion block 23 is placed in the middle of the bottom inner wall of the mounting seat 21, at this time, the arc-shaped groove at the top end of the cushion block 23 faces upwards, then the connecting rod 1 can be implanted into the patient's body through the percutaneous puncture channel, and its position is adjusted so as to accurately fall into the arc-shaped groove of the cushion block 23 and the U-shaped notch of the other two inner walls of the mounting seat 21, the arc-shaped groove tightly fits the outer wall of the connecting rod 1, which not only provides stable support for the connecting rod 1, but also avoids tissue damage caused by hard contact, then the mounting block 24 is aligned with the mounting groove 22 of the two inner walls of the mounting seat 21, the screw strip structure matched with the outer wall of the mounting block 24 and the mounting groove 22 is used, the mounting block 24 is screwed into the mounting seat 21 by rotating the mounting block 24, so as to firmly fix the connecting rod 1 in the mounting seat 21, thus, the stable connection between the connecting rod 1 and the pedicle screw 3 is realized through the mounting mechanism 2, if multiple connecting rods 1 need to be connected to expand the fixed range, the universal ball head 44 at one end of one connecting rod 1 can be clamped into the matching groove of the connecting sleeve 41 at the other end of another connecting rod 1, at this time, the universal ball head 44 can be flexibly rotated in the groove to adapt to the natural physiological curvature of the spine, after being adjusted to the appropriate angle, the locking sleeve 45 is held by hand to make the locking groove 46 on the inner wall thereof threadedly connected with the connecting groove 43 on the outer wall of the connecting sleeve 41, and then the locking bolts 42 on both sides of the connecting sleeve 41 are screwed in, the angle locking of the universal ball head 44 is realized through the extrusion of the bolts, which effectively avoids the loosening of the connecting part, this design also supports the convenient disassembly of two connecting rods 1, which is convenient for replacing the connecting rod 1 of the appropriate specification according to the actual physiological curvature of the patient's vertebrae, significantly improving the adaptability of the reduction device to different anatomical structures, this modular design enables the device to more accurately fit the patient's spinal shape, which not only reduces the difficulty of operation, but also guarantees the accuracy of fracture reduction, and provides reliable support for long-term stability after operation.

[0063] The foregoing merely describes certain exemplary embodiments of the present application by way of illustration, and it is needless to say that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present application. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present application.

Claims

1. A minimally-invasive, degradable, reduction device for thoracolumbar fractures, characterized in that, Include: Connecting rod (1); Mounting mechanism (2), socketed installed on the outer wall of the connecting rod (1); Pedicle screw (3), movably inserted into the middle of the top of the mounting mechanism (2); Implant mechanism (5), inserted into the middle of the top of the pedicle screw (3); Connecting mechanism (4), detachably mounted on both ends of the connecting rod (1); The connecting rod (1), mounting mechanism (2), pedicle screw (3) and connecting mechanism (4) are provided with a plurality of, a plurality of the pedicle screw (3) corresponds to the distribution of the pedicle of the upper and lower vertebral body of the injured vertebra; The pedicle screw (3) comprises a screw body (31), a reinforcing leaf (32) and a screw ball head (34), the reinforcing leaf (32) is arranged on the lower part of the outer wall of the screw body (31), and the screw ball head (34) is arranged on the top end of the screw body (31), and the screw ball head (34) is connected with the mounting mechanism (2); The screw body (31) comprises a core layer (311), a transition layer (312), a surface layer (313) and a delayed degradation coating (314), the transition layer (312) is arranged on the outer wall of the core layer (311), the surface layer (313) is arranged on the outer wall of the transition layer (312), and the delayed degradation coating (314) is coated on the outer wall of the surface layer (313).

2. A minimally-invasive, degradable reduction device for thoracolumbar fractures as claimed in claim 1, wherein, The pedicle screw (3) further comprises a plurality of expansion grooves (33), a positioning clamping groove (35), an expansion screw (36) and a limiting clamping groove (37), a plurality of the expansion grooves (33) are formed on the lower side of the outer wall of the screw body (31), the positioning clamping groove (35) is formed in the middle of the top of the screw ball head (34), the expansion screw (36) is screwedly installed in the interior of the screw body (31), and the limiting clamping groove (37) is formed in the middle of the top of the expansion screw (36).

3. A minimally-invasive, degradable reduction device for thoracolumbar fractures as claimed in claim 2, wherein, The implant mechanism (5) comprises an implant cylinder (51), a positioning clamping block (52), a rotating ring (53), an implant rod (54), a limiting clamping block (55) and a rotating handle (56), the positioning clamping block (52) is mounted on the bottom end of the implant cylinder (51), the rotating ring (53) is mounted on the upper side of the outer wall of the implant cylinder (51), the implant rod (54) is movably inserted into the interior of the implant cylinder (51), the limiting clamping block (55) is mounted on the bottom end of the implant rod (54), and the rotating handle (56) is mounted on the top end of the implant rod (54).

4. A minimally-invasive, degradable reduction device for thoracolumbar fractures as claimed in claim 1, wherein, The mounting mechanism (2) comprises a mounting seat (21), a plurality of mounting grooves (22), a pad (23), a mounting block (24) and an adjusting groove (25), the mounting seat (21) is sleeved on the outer surface of the connecting rod (1), a plurality of the mounting grooves (22) are formed on the inner walls of both sides of the mounting seat (21), respectively, the pad (23) is placed in the middle of the bottom inner wall of the mounting seat (21), the mounting block (24) is screwedly installed between the inner walls of both sides of the mounting seat (21), and the adjusting groove (25) is formed in the middle of the top of the mounting block (24).

5. A minimally-invasive, degradable reduction device for thoracolumbar fractures as defined in claim 1, wherein, The connecting mechanism (4) comprises a connecting sleeve (41), two locking bolts (42), a connecting groove (43), a universal ball head (44), a locking sleeve (45) and a locking groove (46), the connecting sleeve (41) is installed at one end of the connecting rod (1), the two locking bolts (42) are respectively embeddedly installed on the two side outer walls of the connecting sleeve (41), the connecting groove (43) is arranged on the right side of the outer wall of the connecting sleeve (41), the universal ball head (44) is installed at the other end of the connecting rod (1), and the universal ball head (44) is clamped with the connecting sleeve (41), the locking sleeve (45) is sleeved on the outer surface of the universal ball head (44), and the locking groove (46) is arranged on the left side of the inner wall of the locking sleeve (45).

6. A minimally-invasive, degradable reduction device for thoracolumbar fractures as defined in claim 1, wherein, The connecting rod (1), the mounting mechanism (2), the pedicle screw (3) and the connecting mechanism (4) are all made of PLGA, polylactic acid or magnesium alloy material, and the surfaces of the connecting rod (1), the mounting mechanism (2) and the connecting mechanism (4) are all coated with a coating layer made of the same material as the delayed degradation coating layer (314) of the screw body (31), the core layer (311) is arranged as a high-strength dense matrix, the porosity gradient of the transition layer (312) increases from inside to outside, and the grain size of the transition layer (312) is correspondingly refined, and the surface layer (313) is arranged as a nano-scale porous structure.

7. A minimally-invasive, degradable reduction device for thoracolumbar fractures as claimed in claim 2, wherein, The positioning clamping groove (35) and the limiting clamping groove (37) are both arranged as regular hexagonal structures, the screw body (31) is designed as a hollow structure, the inner lower side of the hollow cavity of the screw body (31) and the lower part of the outer surface of the expansion screw rod (36) are both arranged as conical structures, and the reinforcing leaf (32) is arranged as a spiral structure.

8. A minimally-invasive, degradable reduction device for thoracolumbar fractures as defined in claim 3, wherein, The positioning clamping block (52) and the limiting clamping block (55) are both arranged as regular hexagonal structures, the positioning clamping block (52) is clamped with the positioning clamping groove (35), the limiting clamping block (55) is clamped with the limiting clamping groove (37), and the lower part of the outer surface of the limiting clamping block (55) is arranged as a hexagonal pyramid structure.

9. A minimally-invasive, degradable reduction device for thoracolumbar fractures as defined in claim 4, wherein, U-shaped notches are arranged on the other two inner walls of the mounting seat (21), an arc-shaped groove is arranged on the top middle part of the cushion block (23), and a spiral strip matched with the mounting groove (22) is arranged on the outer wall of the mounting block (24).

10. A minimally-invasive, degradable reduction device for thoracolumbar fractures as defined in claim 5, wherein, Grooves matched with the universal ball head (44) are arranged in the connecting sleeve (41) and the locking sleeve (45), the locking sleeve (45) is threadedly connected with the connecting groove (43) on the connecting sleeve (41) through the locking groove (46), and a plurality of anti-skid grooves are arranged on the outer wall of the locking sleeve (45).

Images