CN219289655U - Anterior cervical spine nailing plate system - Google Patents

Abstract

The utility model discloses a front cervical spine screw plate system, which belongs to the technical field of orthopedic implants, wherein at least two pairs of screw holes are arranged on the left side and the right side of the front cervical spine screw plate, a locking groove intersecting the pair of screw holes is arranged between each pair of screw holes, and a lock is rotationally assembled in the locking groove, wherein: a lock catch limiting table is arranged at one side of the lock catch groove away from the corresponding pair of screw holes, the lock catch comprises a split type pressing plate and a hinge shaft positioned in the middle of the pressing plate, and limiting grooves which are clamped with the lock catch limiting tables are formed in the lower surface of each split type of the pressing plate; the two sides of the lock catch limiting table are provided with first guide inclined planes, and the edge of the lower surface of the pressing plate between each split is provided with a second guide inclined plane matched with the first guide inclined planes. The anterior cervical spine nail plate system is firmly fixed, the lock catch can be used for multiple times, the selection of doctors is multiple, and the diversity of operation schemes can be met.

Description

Anterior cervical spine nailing plate system

Technical Field

The utility model relates to the technical field of orthopedic implants, in particular to a cervical spine anterior approach nail plate system.

Background

The anterior cervical decompression operation has been widely applied to cervical degeneration, cervical trauma, tumor, spine instability and other diseases, and has been increasingly widely applied to the fixation of bone grafting after the secondary total excision of intervertebral discs and vertebral bodies. The anterior cervical decompression and fusion operation has obvious advantages in treating cervical spondylosis, cervical fracture dislocation, spinal cord injury and the like, and has ideal curative effect. The anterior cervical surgery is convenient to operate and is beneficial to postoperative recovery.

In the intraspinal fixation of the cervical spine, it is often necessary to connect bone plates to two or more segments of the upper and lower vertebral bodies with spinal screws to achieve fixation. However, the cervical vertebra of the human body has a large activity, and the esophagus and surrounding tissues are in front of the vertebral body. The anterior cervical bone plate in the prior art has at least the following problems: the spine screw is not thoroughly fixed to the anterior cervical bone plate, or the lock catch can not effectively prevent the spine screw from withdrawing, so that the selection of doctors is less, and the diversity of operation schemes can not be met.

Disclosure of Invention

The utility model aims to solve the technical problem of providing a cervical spine forward nailing plate system which is firmly fixed and can be used repeatedly by a lock catch.

In order to solve the technical problems, the utility model provides the following technical scheme:

the utility model provides a way nail board system before cervical vertebra, includes way bone board before the cervical vertebra, the left and right sides of way bone board before the cervical vertebra is equipped with two at least pairs of screw holes, all is equipped with the hasp groove crossing with this pair of screw hole between every pair of screw hole, the hasp inslot internal rotation is equipped with the hasp that is used for preventing screw withdrawal in the screw hole, wherein:

a lock catch limiting table is arranged at one side of the lock catch groove away from the corresponding pair of screw holes, the lock catch comprises a split type pressing plate and a hinge shaft positioned in the middle of the pressing plate, and limiting grooves which are clamped with the lock catch limiting table are formed in the lower surface of each split type of the pressing plate;

the two sides of the lock catch limiting table are provided with first guide inclined planes, and the edge of the lower surface of the pressing plate between each split is provided with a second guide inclined plane matched with the first guide inclined planes.

Further, the latch groove is positioned at the part between the corresponding pair of screw holes, and the edge of the latch groove is provided with a transition inclined plane;

and/or the hinge shaft of the lock catch is a riveting hole, and the lock catch is connected in the lock catch groove by flanging the riveting hole in a riveting way;

and/or the pressing plates of the lock catches are of a three-flap structure which is uniformly distributed;

and/or the number of the driving holes of the lock catch is one and is positioned in the middle of the pressing plate, or the number of the driving holes of the lock catch is at least two and is positioned on the split of the pressing plate.

Further, the transition bevel comprises an upper bevel portion and a lower fillet portion, wherein the angle between the bevel portion and the root portion plane is 15-25 degrees.

Further, the screw hole sequentially comprises a screw guide ball socket, a screw matching ball socket and a safe straight surface from top to bottom, the inner diameter of the screw guide ball socket is larger than that of the screw matching ball socket, and the inner diameter of the safe straight surface is smaller than that of the screw matching ball socket.

Further, the inner diameter of the screw guide ball socket is 0.5-2mm larger than the inner diameter of the screw matched ball socket;

and/or the ball center distance between the screw guide ball socket and the screw matching ball socket is 1-3mm;

and/or the length of the safety straight surface is 0.3-0.8mm;

and/or the inner diameter of the safe straight surface is 0.4-1mm smaller than the inner diameter of the screw matched ball socket;

and/or the screw hole further comprises a dovetail clearance structure positioned below the safety straight face.

Further, a perspective window is arranged on the anterior cervical bone plate;

and/or the lower surface of the cervical vertebra anterior bone plate in the length direction is a sagittal arc;

and/or the lower surface of the cervical vertebra anterior bone plate in the width direction is a crown surface arc;

and/or the edge of the anterior cervical vertebra bone plate is provided with a peripheral round corner, and the peripheral round corner sequentially comprises an upper round corner, a transition straight line and a lower round corner from top to bottom.

Further, the screw in the screw hole comprises at least one of a variable angle self-drilling screw, a fixed angle self-drilling screw, a variable angle self-tapping screw and a fixed angle self-tapping screw.

Further, the pin head of screw in the screw hole all includes the cooperation sphere, is located the cooperation axial plane of cooperation sphere below, be located prevent moving back the face of cooperation sphere top, and be located prevent moving back the empty face of preventing moving back the face top, wherein:

the matched spherical surface is used for being matched with the screw matched ball socket, and the outer diameter of the matched spherical surface is the same as the inner diameter of the screw matched ball socket;

the matching shaft surface is used for matching with the safety straight surface, and the outer diameter of the matching shaft surface is smaller than or equal to the inner diameter of the safety straight surface;

the anti-withdrawal surface is used for being matched with a pressing plate of the lock catch.

Further, the shank of the screw in the screw hole is provided with an upper section of thread and a lower section of thread, and the difference between the major diameter and the minor diameter of the upper section of thread is smaller than the difference between the major diameter and the minor diameter of the lower section of thread.

Further, the screw in the screw hole is a self-drilling screw, and a self-drilling screw tip is arranged at the tail end of a screw rod of the self-drilling screw;

or the screw in the screw hole is a self-tapping screw, the tail end of the screw rod of the self-tapping screw is provided with a self-tapping top circle, and the diameter of the self-tapping top circle is the same as the large diameter of the thread of the lower section of thread;

or, a self-tapping groove is formed in the side face of the tail end of the screw rod of the screw in the screw hole.

The utility model has the following beneficial effects:

according to the cervical vertebra anterior approach nail plate system, firstly, the lock catch groove is provided with the lock catch limiting table, and the lower surface of each split of the pressure plate of the lock catch is provided with the limiting groove which is clamped with the lock catch limiting table, so that the lock catch can be limited from freely rotating after covering a screw, the blocking effect of the pressure plate can be ensured, and the anti-withdrawal effect on the screw is improved; secondly, the both sides of the spacing platform of hasp are equipped with first direction inclined plane, and the clamp plate is equipped with the second direction inclined plane with first direction inclined plane matched with at the lower surface edge between each split, and resistance when these two direction inclined planes can reduce the hasp and rotate, avoid damaging the rotation assembly of hasp, avoid the hasp to drop from the bone plate, can also avoid damaging spacing recess and the spacing platform edge of hasp, ensure that the hasp can reuse when repairing or adjusting anterior cervical vertebra bone plate.

Drawings

FIG. 1 is a schematic view of a partial structure of a cervical anterior bone plate according to the prior art, in which (a) is a perspective view in one direction and (b) is a perspective view in the other direction;

FIG. 2 is a schematic view showing the structure of the anterior cervical plate system of the present utility model, wherein (a) is a side view and (b) is a top view;

FIG. 3 is a schematic view of the anterior cervical plate (with buckle) of FIG. 2, wherein (a) is a cross-sectional view in the longitudinal direction, (b) is a side view, (c) is a top view, and (d) is a cross-sectional view in the width direction;

FIG. 4 is a schematic view of the anterior cervical plate of FIG. 2 (without the locking device), wherein (a) is a top view and (b) is an E-E cross-sectional view;

FIG. 5 is a schematic structural view of the latch of FIG. 2, wherein (a) is a perspective view of one direction of the first structural form, (b) is a perspective view of the other direction of the first structural form, (c) is a perspective view of one direction of the second structural form, and (d) is a perspective view of the other direction of the second structural form;

FIG. 6 is a schematic view of the anterior cervical plate of FIG. 2 in different sizes;

FIG. 7 is a schematic view of one embodiment of the screw in the screw hole of FIG. 2, wherein (a) is a front view and (b) is a top view of the head;

FIG. 8 is a schematic view of another embodiment of the screw in the screw hole of FIG. 2, wherein (a) is a front view and (b) is a top view of the head;

FIG. 9 is a schematic view of another embodiment of the screw in the screw hole of FIG. 2, wherein (a) is a front view and (b) is a top view of the head;

fig. 10 is a schematic view of another embodiment of the screw in the screw hole of fig. 2, wherein (a) is a front view and (b) is a top view of the head.

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved more apparent, the following detailed description will be given with reference to the accompanying drawings and specific embodiments.

The utility model provides a cervical spine anterior approach nail plate system, as shown in fig. 2-10, comprising a cervical spine anterior approach bone plate 10, wherein at least two pairs of screw holes 14 (3 pairs in the embodiment shown in fig. 2-4, the specific number can be flexibly set according to the length and the requirement of the bone plate) are arranged at the left side and the right side of the cervical spine anterior approach bone plate 10, a locking groove 19 intersecting with the pair of screw holes 14 is arranged between each pair of screw holes 14, a locking buckle 11 for preventing the screw in the screw hole 14 from withdrawing is rotationally assembled in the locking groove 19, wherein:

a latch stopper 16 is provided on one side of the latch groove 19 away from the corresponding pair of screw holes 14 (see fig. 4 (a), for the left pair of screw holes, on the right side of the corresponding latch groove, for the middle pair of screw holes and the right pair of screw holes, on the left side of the corresponding latch groove), the latch 11 includes a split-type pressing plate 111 and a hinge shaft located in the middle of the pressing plate 111, and a stopper groove 112 engaged with the latch stopper 16 is provided on the lower surface of each split of the pressing plate 111;

the two sides of the lock catch limiting table 16 (the upper side and the lower side in fig. 4 (a)) are provided with first guide inclined planes 161, the edge of the lower surface of the pressing plate 111 between each split is provided with a second guide inclined plane 113 matched with the first guide inclined planes 161, the two guide inclined planes are the first main characteristics of the application, the conventional products are right-angle straight sides, the resistance is relatively large when the lock catch 11 is rotated, the rotating assembly of the lock catch 11 is damaged, the lock catch 11 is caused to fall off from a bone plate, and the limit groove 112 and the edge of the lock catch limiting table 16 are damaged and cannot be reused when repairing or adjusting the cervical vertebra front bone plate 10.

When the screw locking device is used, the lock catch 11 is rotated to enable each split of the pressing plate 111 of the lock catch 11 to be completely separated from the intersection of the lock catch groove 19 and the corresponding pair of screw holes 14, so that interference between the screw and the split of the pressing plate 111 when the screw is installed in the screw hole 14 can be avoided, and the screw can be smoothly installed in the screw hole 14; when the screw is mounted to the screw hole 14, the rotation of the locker 11 causes the split of the pressing plate 111 of the locker 11 to be caught at the intersection of the locker groove 19 and the corresponding pair of screw holes 14, thus preventing the screw from being withdrawn from the screw hole 14. When the split of the pressing plate 111 of the latch 11 is clamped into the intersection of the latch groove 19 and the corresponding pair of screw holes 14, the latch limiting table 16 in the latch groove 19 is clamped with the limiting groove 112 on the lower split surface of the pressing plate 111 of the latch 11, so as to prevent the latch 11 and the anterior cervical bone plate 10 from rotating relatively (i.e., limit the latch 11 from rotating freely after covering the screw), thereby ensuring the blocking effect of the pressing plate 111 and improving the anti-withdrawal effect on the screw.

According to the cervical vertebra anterior approach nail plate system, firstly, the lock catch groove is provided with the lock catch limiting table, and the lower surface of each split of the pressure plate of the lock catch is provided with the limiting groove which is clamped with the lock catch limiting table, so that the lock catch can be limited from freely rotating after covering a screw, the blocking effect of the pressure plate can be ensured, and the anti-withdrawal effect on the screw is improved; secondly, the both sides of the spacing platform of hasp are equipped with first direction inclined plane, and the clamp plate is equipped with the second direction inclined plane with first direction inclined plane matched with at the lower surface edge between each split, and resistance when these two direction inclined planes can reduce the hasp and rotate, avoid damaging the rotation assembly of hasp, avoid the hasp to drop from the bone plate, can also avoid damaging spacing recess and the spacing platform edge of hasp, ensure that the hasp can reuse when repairing or adjusting anterior cervical vertebra bone plate. Therefore, the anterior cervical spine nail plate system has firm fixation of the bone plate, can be repeatedly used, has multiple choices for doctors, and can meet the diversity of operation schemes. The utility model is suitable for being used as a nail plate system for spine cervical vertebra decompression fusion fixation.

The inventor finds that the anterior cervical bone plate in the prior art has the following problems in the research process: (1) Usually, the thickness of the bone plate is large, and dysphagia and pain of patients are easy to cause after operation; (2) The structural design of the anterior cervical bone plate is that the bone plate is easy to break after operation, so that implantation fails.

To solve this problem, preferably, the portion of the locking groove 19 located between the corresponding pair of screw holes 14 has a transition slope 12 at the edge thereof, and the transition slope 12 is a second main feature of the present application, where the anterior cervical plate 10 is designed and verified to reduce or avoid dysphagia and pain of the patient after surgery, and to meet the structural strength requirement of the anterior cervical plate 10. The conventional anterior cervical bone plate is either thick, which causes postoperative dysphagia and pain to patients, or the locking position is a right-angled straight edge 19' (shown in fig. 1), which cannot withstand mechanical fatigue test, and thus cannot be used clinically, or causes risk hidden trouble of plate breakage to clinic.

Like this, because the hasp groove intersects with a pair of screw hole, the part that causes between a pair of screw hole is the relative weak area of bone plate, and the edge that the hasp groove is located the part between a pair of corresponding screw hole in this application is equipped with the transition inclined plane to stress is removed to this relative weak area, and reinforced structure design makes the bone plate satisfy the structural strength requirement, and the bone plate can design thinness, reduces or avoids postoperative patient dysphagia, pain, and greatly reduced the cracked risk of bone plate. Therefore, the anterior cervical approach nail plate system of the utility model, the bone plate meets the structural strength requirement, can be designed thinner, reduces or avoids dysphagia and pain of postoperative patients, and greatly reduces the risk of fracture of the bone plate.

The lock catch 11 is an assembly component on the anterior cervical plate 10, for facilitating the rotation assembly of the lock catch 11, as shown in fig. 5, the hinge shaft of the lock catch 11 may be a riveting hole 115, and the lock catch 11 is riveted and connected in the lock catch groove 19 by flanging (specifically, pressing or punching) the riveting hole 115. In specific implementation, the hole diameter of the riveting hole 115 and the outer diameter can form a wall thickness of 0.15-0.35mm, and the depth of the hole can be 0.5-0.8mm, so that after the lock catch 11 is riveted, the lock catch 11 can be rotated around the center of the lock catch 11.

The pressing plate 111 of the lock catch 11 may have a three-lobe structure which is uniformly distributed, and each lobe is equally divided into a circle at 120 degrees. During operation, a doctor can insert a tool into the driving hole 114 to rotate the lock catch 11, rotate the pressing plate 111 to the screw hole 14 of the cervical vertebra anterior approach bone plate 10, and in the rotating process, one split of the pressing plate 111 is clamped with the lock catch limiting table 16 in the lock catch groove 19, and the other two split can cover the anti-withdrawal surface 23 of the screw, and can avoid the anti-withdrawal empty surface 24.

As shown in (a) - (b) of fig. 5, the driving hole 114 of the latch 11 may be one and located at the middle of the pressing plate 111, and in this case, the driving hole 114 may be in the form of a quincuncial hole pattern; as shown in fig. 5 (c) - (d), the driving holes 114 of the lock catch 11 may be at least two and located on the split of the pressing plate 111, and in this case, the driving holes 114 may be in the form of three (round) holes uniformly distributed on the pressing plate 111. The quincuncial hole pattern may facilitate the aiming and insertion of the tool into the driving hole 114; the driving force of the uniformly distributed three-hole type is smaller and the stress is more uniform. The arrangement of the driving hole 114 is convenient for aiming the tool during operation, can reduce the repetition of the operation process, shorten the operation time and reduce the potential safety hazard of the operation.

As shown in fig. 3-4, the transition chamfer 12 preferably includes an upper chamfer portion 121 and a lower rounded portion 122, with the angle between the chamfer portion 121 and its root plane being 15-25 degrees. Rounded portions 122 may be R0.1-R0.5mm. Thus, the stress concentration can be effectively avoided through the inclined surface part 121 and the round corner part 122, the strength and the safety performance of the product are improved, and doctors and patients are more relieved before, during and after the operation.

Screw hole 14 cooperates with the screw of the assembly on anterior cervical plate 10, for the convenience of screw fixation, screw hole 14 preferably includes screw guide ball socket 141, screw cooperation ball socket 142 and safe straight face 143 in proper order from top to bottom, wherein:

the inner diameter of the screw guiding ball socket 141 is larger than that of the screw matching ball socket 142, and can be 0.5-2mm larger, and the screw guiding ball socket 141 is used for guiding the screw to enter the screw matching ball socket 142;

the distance between the center of the screw guide ball socket 141 and the center of the screw matching ball socket 142 can be 1-3mm, and the complete arc under the center of the screw matching ball socket 142 is ensured;

the inner diameter of the safety straight face 143 is smaller than that of the screw-fit ball socket 142, and can be specifically 0.4-1mm smaller; the safety straight face 143 is the primary safety feature of the screw hole 14 and may have an (axial) length of 0.3-0.8mm, which ensures that the screw does not become dislodged from the screw hole when it is engaged with the bone plate. Compared with the conventional products, the ball head part of the screw often falls out of the screw hole of the bone plate, so that the operation fails or the potential safety hazard after the operation is increased.

Screw hole 14 may also include a dovetail clearance feature 144 below safety straight face 143, which facilitates a greater "universal" angle of the variable angle screw, and a smoother, non-interfering.

As shown in fig. 3 (c), the anterior cervical bone plate 10 may be provided with a perspective window 13, where the perspective window 13 is convenient for a doctor to observe during operation, and reduces the weight of the anterior cervical bone plate 10, and meanwhile, the clearance can be increased on the basis of thinness of the bone plate, so that the anterior cervical bone plate has a good effect of reducing or avoiding dysphagia and pain of a patient after operation.

According to the difference of the length of the anterior cervical plate 10 and the number of the screw holes 14, the number of the see-through windows 13 can be flexibly changed, as shown in fig. 6, (a) the corresponding bone plate 10 is provided with four screw holes 14, and the distance between the centers of two screw holes 14 farthest along the length direction of the bone plate 10 is 12mm, which is recorded as 4-12mm (the same applies below), (b) the corresponding screw holes are 4-14 mm-4-16 mm, (c) the corresponding screw holes are 4-18 mm-4-30 mm, (d) the corresponding screw holes are 6-30 mm-6-32 mm, (e) the corresponding screw holes are 6-34 mm-6-44 mm, (f) the corresponding screw holes are 8-42 mm-8-48 mm, (g) the corresponding screw holes are 8-51 mm-8-66 mm, (h) the corresponding screw holes are 10-64mm, (i) the corresponding screw holes 10-68 mm-10-88 mm, wherein the non-see-through windows are arranged in (c), (d) and (f) 1 see-through window are arranged in each of, (e) and (h) 2) the see-through windows are arranged in each of the two.

As further shown in fig. 3-4, the lengthwise lower surface of anterior cervical plate 10 may be a sagittal arc 17 and the widthwise lower surface of anterior cervical plate 10 may be a coronal arc 18. The sagittal plane arc 17 and the coronal plane arc 18 are designed according to the physiological curvature of the sagittal plane and the coronal plane of the vertebral body of the human body at the beginning of the design of the application, and the arcs in two directions can enable the bone plate in the application to be more attached to the cervical vertebra surface of the human body, so that the protruding position is avoided, the operation experience of doctors is improved, and the postoperative comfort of the patient is increased.

The edge of anterior cervical vertebra bone plate 10 can be equipped with circle fillet 15, and circle fillet 15 is another feature of this application, and circle fillet 15 is from last to including fillet 151, transition fillet 152, transition straight line 153 and fillet 154 down in proper order down, and four sections circular arcs altogether, line segment are constituteed. These features allow for smooth, bone-engaging extension of the edges of the anterior cervical plate 10 of the present application, while allowing for a thinner edge portion of the plate relative to the middle portion, while providing for a smooth transition to the cervical spine. The upper edge of the bone plate is similarly cut off with a bevel when seen in cross section, avoiding the thick or sharp edge of the conventional bone plate to stimulate muscles.

As shown in fig. 2, the screws in the screw holes 14 may take various forms, and may include at least one of a variable angle self-drilling screw 20 (fig. 7), a fixed angle self-drilling screw 30 (fig. 8), a variable angle self-tapping screw 40 (fig. 9), and a fixed angle self-tapping screw 50 (fig. 10) according to different forms of their engagement with the anterior cervical plate 10. In practice, one of the screws can be selected to be matched with the anterior cervical plate 10 according to the application and the function.

As shown in fig. 7-10, the heads of the screws 20, 30, 40, 50 within the screw hole 14 may each include a mating spherical surface 22, a mating axial surface 25 below the mating spherical surface 22, a back-out preventing surface 23 above the mating spherical surface 22, and a back-out preventing surface 24 above the back-out preventing surface 23, wherein:

the matched spherical surface 22 is used for being matched with the screw matched ball socket 142 in the screw hole 14, the outer diameter of the matched spherical surface 22 is the same as or similar to the inner diameter of the screw matched ball socket 142, free rotation and swing of the matched spherical surface 22 in the screw matched ball socket 142 can be ensured, and preparation for realizing a universal function is provided;

the mating shaft surface 25 is used for mating with the safe straight surface 143 in the screw hole 14, the outer diameter of the mating shaft surface 25 is smaller than or equal to the inner diameter of the safe straight surface 143, specifically, the outer diameter of the mating shaft surface 25 is smaller than the inner diameter of the safe straight surface 143 (can be smaller than 0.6-1mm in particular), so as to realize the universal function of the variable angle screw, and the outer diameter of the mating shaft surface 25 is close to the inner diameter of the safe straight surface 143 (can be smaller than 0.02-0.1mm in particular), so as to realize the one-way stable fixation of the fixed angle screw;

the anti-back surface 23 is used for matching with the pressing plate 111 of the lock catch 11, and the design of the anti-back surface 23 is that after the screw is beaten on the cervical vertebra, the screw can be covered by the pressing plate 111 of the lock catch 11 to prevent the screw from loosening and backing out along with the movement of the cervical vertebra of the patient after operation, thereby causing the operation failure of the patient and increasing the pain of the patient.

The head ends of the screws 20, 30, 40, 50 may be provided with drive slots 21 for holding the screws through the screw holes 14 in the bone plate and onto the vertebral bodies. The driving groove 21 may have various structures such as a quincuncial hole and a polygonal hole.

The anti-back-out surface 23 and the anti-back-out empty surface 24 cooperate to ensure the depth of the screw driving groove 21, increase the strength of the screw driving groove 21, and reduce the notch height of the screw exposed out of the bone plate, and as can be seen from fig. 2 (a), the screw holes 14 at two ends of the bone plate are usually locked with variable angle screws, and the screw holes 14 in the middle are usually locked with fixed angle screws. When locking the variable angle screw, it can be seen that the screw is driven into the cone at an angle, whereby the bulb edge of the screw is cocked, the design of the anti-back-out relief surface 24 reduces the screw notch height to some extent.

The shank of the screws 20, 30, 40, 50 in the screw hole 14 is preferably provided with an upper thread 27 and a lower thread 28, and the difference between the major diameter and the minor diameter of the upper thread 27 is smaller than the difference between the major diameter and the minor diameter of the lower thread 28. The upper thread 27 is close to the ball head/nail head of the screw, and is also at the surface layer of cortical bone of the vertebral body, the fall of the small diameter and the large diameter of the upper thread 27 is smaller, so that the contact area of the upper thread 27 of the screw on the vertebral body is increased, the anti-falling force of the screw from the vertebral body is increased, and the stable fixation of the screw and the bone plate is improved.

The self-drilling screws 20, 30 are distinguished from the self-tapping screws 40, 50 primarily at the point of the nail and the lower thread. The tail end (tip) of the shank of the self- drilling screw 20, 30 can be provided with a self-drilling tip 29, the self-drilling tip 29 is a point, here a taper from small to large, and the difference between the small diameter and the large diameter of the lower thread 28 is larger, so that the screw can be conveniently and rapidly driven into the vertebral body like a drill bit.

The shank ends (spikes) of the self-tapping screws 40, 50 may be provided with self-tapping tip circles 32, the diameter of the self-tapping tip circles 32 being the same as the major diameter of the lower thread 28, and the major diameter of the lower thread 28 being substantially the same as the major diameter of the upper thread 27, although the self-drilling screws 20, 30 are not as convenient to drive in, but the strength of their fixation to the vertebral body is highest. In particular, the self-tapping screws 40, 50 are suitable for use with osteoporotic patients and where the repair procedure has been performed with a hole to enhance fixation of the bone plate, screw and vertebral body.

The side surface of the tail end of the screw rod of the screw 20, 30, 40 and 50 in the screw hole 14 can be provided with a self-tapping groove 26, namely a notch with an increased tip is formed in the self-tapping groove 26, so that when the screw is driven into a vertebral body, the vertebral body is cut by the self-tapping groove 26, and bone fragments and the like are discharged.

While the foregoing is directed to the preferred embodiments of the present utility model, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present utility model, and such modifications and adaptations are intended to be comprehended within the scope of the present utility model.

Claims (10)

1. The anterior cervical spine screw plate system comprises an anterior cervical spine bone plate, at least two pairs of screw holes are arranged on the left side and the right side of the anterior cervical spine bone plate, a locking groove intersecting with the pair of screw holes is arranged between each pair of screw holes, a lock catch for preventing the screw in the screw hole from withdrawing is rotationally assembled in the locking groove,

a lock catch limiting table is arranged at one side of the lock catch groove away from the corresponding pair of screw holes, the lock catch comprises a split type pressing plate and a hinge shaft positioned in the middle of the pressing plate, and limiting grooves which are clamped with the lock catch limiting table are formed in the lower surface of each split type of the pressing plate;

the two sides of the lock catch limiting table are provided with first guide inclined planes, and the edge of the lower surface of the pressing plate between each split is provided with a second guide inclined plane matched with the first guide inclined planes.

2. The anterior cervical plating system of claim 1, wherein the portion of the locking groove between the corresponding pair of screw holes has a transition bevel at an edge thereof;

and/or the hinge shaft of the lock catch is a riveting hole, and the lock catch is connected in the lock catch groove by flanging the riveting hole in a riveting way;

and/or the pressing plates of the lock catches are of a three-flap structure which is uniformly distributed;

and/or the number of the driving holes of the lock catch is one and is positioned in the middle of the pressing plate, or the number of the driving holes of the lock catch is at least two and is positioned on the split of the pressing plate.

3. The anterior cervical plate system of claim 2, wherein the transition chamfer comprises an upwardly located chamfer portion and a downwardly located rounded corner portion, the angle between the chamfer portion and its root plane being 15-25 degrees.

4. The anterior cervical plating system of any of claims 1-3, wherein the screw hole comprises, in order from top to bottom, a screw guiding socket, a screw mating socket, and a safety straight surface, the inner diameter of the screw guiding socket being greater than the inner diameter of the screw mating socket, the inner diameter of the safety straight surface being less than the inner diameter of the screw mating socket.

5. The anterior cervical plate system of claim 4, wherein the screw-guiding socket has an inner diameter that is 0.5-2mm greater than an inner diameter of the screw-mating socket;

and/or the ball center distance between the screw guide ball socket and the screw matching ball socket is 1-3mm;

and/or the length of the safety straight surface is 0.3-0.8mm;

and/or the inner diameter of the safe straight surface is 0.4-1mm smaller than the inner diameter of the screw matched ball socket;

and/or the screw hole further comprises a dovetail clearance structure positioned below the safety straight face.

6. The anterior cervical plate system of claim 4, wherein the anterior cervical plate has a perspective window;

and/or the lower surface of the cervical vertebra anterior bone plate in the length direction is a sagittal arc;

and/or the lower surface of the cervical vertebra anterior bone plate in the width direction is a crown surface arc;

and/or the edge of the anterior cervical vertebra bone plate is provided with a peripheral round corner, and the peripheral round corner sequentially comprises an upper round corner, a transition straight line and a lower round corner from top to bottom.

7. The anterior cervical plating system of claim 4, wherein the screw within the screw hole comprises at least one of a variable angle self-drilling screw, a fixed angle self-drilling screw, a variable angle self-tapping screw, a fixed angle self-tapping screw.

8. The anterior cervical plating system of claim 4, wherein the heads of the screws in the screw holes each comprise a mating spherical surface, a mating axial surface below the mating spherical surface, an anti-back surface above the mating spherical surface, and an anti-back void surface above the anti-back surface, wherein:

the matched spherical surface is used for being matched with the screw matched ball socket, and the outer diameter of the matched spherical surface is the same as the inner diameter of the screw matched ball socket;

the matching shaft surface is used for matching with the safety straight surface, and the outer diameter of the matching shaft surface is smaller than or equal to the inner diameter of the safety straight surface;

the anti-withdrawal surface is used for being matched with a pressing plate of the lock catch.

9. The anterior cervical plating system of claim 8, wherein the shanks of the screws in the screw holes are each provided with an upper thread and a lower thread, and the difference between the major and minor diameters of the upper thread is smaller than the difference between the major and minor diameters of the lower thread.

10. The anterior cervical plating system of claim 9, wherein the screw in the screw hole is a self-drilling screw having a self-drilling spike at a shank end thereof;

or the screw in the screw hole is a self-tapping screw, the tail end of the screw rod of the self-tapping screw is provided with a self-tapping top circle, and the diameter of the self-tapping top circle is the same as the large diameter of the thread of the lower section of thread;

or, a self-tapping groove is formed in the side face of the tail end of the screw rod of the screw in the screw hole.

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