CN213156366U - Dynamic locking screw and dynamic locking bone fracture plate system - Google Patents

Abstract

The utility model relates to a dynamic locking bone fracture plate system and a dynamic locking screw thereof, wherein the dynamic locking screw comprises a screw head with external threads; the screw rod, one end of the screw rod is inserted in the screwhead and is in clearance fit with the screwhead, the screw rod with be connected through the fixed pin between the screwhead, wherein the fixed pin with screwhead fastening connection, the fixed pin with leave the clearance between the screw rod. After the dynamic locking screw is implanted into a broken bone, the screw rod is connected with the broken bone, the screw head is in threaded connection with the bone fracture plate, and the screw rod is connected with the screw head through the fixing pin. When the bone fracture plate is stressed by soft tissue or external force, the fixing pin can deform and can drive the screw rod to move relative to the screw head.

Description

Dynamic locking screw and dynamic locking bone fracture plate system

Technical Field

The utility model relates to a broken bone connection fixation technical field during orthopedic surgery, in particular to a dynamic locking screw and a dynamic locking bone fracture plate system with the same.

Background

At present, most of the operation internal fixation modes for fracture patients in orthopedics clinic are based on AO theory, and strong internal fixation is emphasized in AO theory, namely, the fracture part is not allowed to move after fracture operation. The traditional multi-purpose locking metal bone fracture plate system for treating the fracture is used for curing the fracture, the locking plate system is composed of a locking nail and a locking plate, the locking nail and the locking plate are connected through threads, the locking nail is implanted into a bone, and the locking nail is connected with internal threads which are pre-tapped on the bone to form a stable internal fixing system.

However, recent studies have found that there are direct healing and indirect healing of fracture, in which callus formation at the fracture end is beneficial to fracture healing, and callus generation is stimulated by stress and relative movement between fracture blocks, but in the conventional locking plate system, the locking plate, the locking nail and the bone are connected by screw threads, which form a stable internal fixation system, so that relative movement between fracture blocks cannot be formed during fracture healing, which is not beneficial to callus formation and fracture healing.

SUMMERY OF THE UTILITY MODEL

Based on this, in order to solve the problem that the traditional nail locking plate system is not beneficial to the formation of callus and the healing of fracture due to the formation of stable internal fixation in the indirect healing process, it is necessary to provide a dynamic locking screw which can make the fracture end form a certain micro-motion under the action of soft tissue stress or external force after being implanted into the human body so as to promote the formation of callus and the healing of fracture. A dynamic locking bone plate system having the dynamic locking screw is also provided.

A dynamic locking screw comprising: a screw head having an external thread; the screw rod, one end of the screw rod is inserted in the screwhead and is in clearance fit with the screwhead, the screw rod with be connected through the fixed pin between the screwhead, wherein the fixed pin with screwhead fastening connection, the fixed pin with leave the clearance between the screw rod.

After the dynamic locking screw is implanted into the broken bone, the screw rod is in threaded connection with the broken bone, the screw head is in threaded connection with the bone fracture plate, and the screw rod is connected with the screw head through the fixing pin; when receiving soft tissue stress or exogenic action, because have the space that allows the fixed pin deformation in the screw pole, the screw pole can move about for the screwhead, and the fixed pin takes place to deform and can drive the relative screwhead activity of screw pole, because screwhead and coaptation board fixed connection, screw pole and broken bone fixed connection, so the screw pole drives the broken bone and produces the activity for the coaptation board, therefore above-mentioned dynamic locking screw produces the fine motion effect when using, makes the relative folded plate of bone activity of broken bone, can promote the formation of callus and the healing of fracture.

In one embodiment, the screw shaft and the screw head are connected by two or more fixing pins, the two or more fixing pins are offset in the axial direction of the screw shaft, and the axes of the two or more fixing pins are offset in phase in the circumferential direction of the screw head.

In one embodiment, the screw shaft and the screw head are connected by two fixing pins, the two fixing pins are staggered in the axial direction of the screw shaft, and the axes of the two fixing pins are perpendicular to each other.

In one embodiment, the screw head comprises a threaded part and a shaft sleeve connected with the threaded part, a connecting hole is formed in the end face, far away from the threaded part, of the shaft sleeve, a first pin hole and a second pin hole are formed in the outer wall of the connecting hole and are arranged along the axial direction of the connecting hole, and the axis of the first pin hole is perpendicular to the axis of the second pin hole; the screw rod comprises a screw shaft and a polished rod connected with the screw shaft, wherein the screw shaft is provided with external threads, the polished rod is provided with a third pin hole and a fourth pin hole which are arranged along the axial direction of the polished rod, the polished rod is inserted into the connecting hole and is in clearance fit with the connecting hole, the third pin hole is matched with the first pin hole, and the fourth pin hole is matched with the second pin hole; the fixing pins comprise a first fixing pin and a second fixing pin, wherein the first fixing pin is connected with the first pin hole and the third pin hole, the first fixing pin is in fastening fit with the first pin hole, the first fixing pin is in clearance fit with the third pin hole, the second fixing pin is connected with the second pin hole and the fourth pin hole, the second fixing pin is in fastening fit with the second pin hole, and the second fixing pin is in clearance fit with the fourth pin hole.

In one embodiment, the third pin hole and/or the fourth pin hole have a shape of: the middle part is cylindrical, and the two ends are horn-shaped with the diameter gradually enlarged to the end parts.

In one embodiment, the first pin hole and/or the second pin hole are blind holes or through holes, and the third pin hole and the fourth pin hole are through holes.

In one embodiment, the fixing pin penetrates through the screw head, and both ends of the fixing pin are exposed out of the outer surface of the shaft sleeve.

In one embodiment, both ends of the fixing pin are not higher than the outer surface of the bushing.

In one embodiment, the two ends of the fixing pin and the screw head are respectively welded together.

Also provided is a dynamic locking bone plate system, which comprises a bone plate and the dynamic locking screw of any one of the embodiments.

Above-mentioned developments locking coaptation board system, when receiving soft tissue stress effect or exogenic action, the fixed pin can take place deformation and can drive the relative screwhead activity of screw pole, because screwhead and coaptation board fixed connection, screw pole and broken bone fixed connection, so the screw pole drives the activity that the broken bone produced for the coaptation board, can promote the formation of callus and the healing of fracture.

Drawings

Fig. 1 is a structural diagram of a dynamic locking screw according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a dynamic locking screw.

Fig. 3 is a perspective view of the head of the dynamic locking screw.

FIG. 4 is a cross-sectional view of the screw head of the dynamic locking screw.

Fig. 5 is a structural view of a fixing pin of the dynamic locking screw.

FIG. 6 is a block diagram of the shaft of the dynamic locking screw.

FIG. 7 is a cross-sectional view of the shaft of the dynamic locking screw.

Fig. 8 is a schematic view of a dynamic locking bone plate system according to an embodiment of the present invention.

The relevant elements in the figures are numbered correspondingly as follows:

100. a dynamic locking screw; 10. a screw head; 110. a threaded portion; 120. a shaft sleeve; 130. connecting holes; 140. a first pin hole; 150. a second pin hole; 20. a screw shaft; 210. a nail shaft; 211. chamfering; 220. a polish rod; 230. a third pin hole; 240. a fourth pin hole; 30. a fixing pin; 310. a first fixing pin; 311. a first axis; 320. a second fixing pin; 321. a second axis; 200. a bone plate; 300. and (5) breaking bones.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

The following describes preferred embodiments of the present invention with reference to the accompanying drawings.

Referring to fig. 1 and 2, a dynamic locking screw 100 according to an embodiment of the present invention includes a screw head 10 having an external thread (not numbered) and a screw shaft 20 having an external thread (not numbered). As shown in FIG. 8, the dynamic locking screw 100 described above may be used with a bone plate 200 to form a dynamic locking bone plate system in which the screw head 10 is threadedly connected to the bone plate 200 and the screw shaft 20 is threadedly connected to the fractured bone 300.

As shown in fig. 2, one end of the screw shaft 20 is inserted into the screw head 10 and forms a clearance fit with the screw head 10, and the two are movable relative to each other. The screw shaft 20 and the screw head 10 are connected by a fixing pin 30, wherein the fixing pin 30 is tightly connected with the screw head 10, and a gap is left between the fixing pin 30 and the screw shaft 20. During specific implementation, the screw rod 20 and the screw head 10 can be respectively provided with a pin hole and connected through a fixing pin 30, the fixing pin 30 and the screw head 10 can be fastened and connected through a welding mode, the size of the fixing pin 30 is slightly smaller than that of the pin hole in the screw rod 20, so that a small gap is formed between the fixing pin 30 and the screw rod 20, and a space allowing the fixing pin 30 to deform is formed in the screw rod 20. Alternatively, the fixing pin 30 and the screw head 10 may be in an interference fit. The axis of the fixing pin 30 extends in the radial direction of the screw shaft 20.

Referring to fig. 8, after the dynamic locking screw 100 is implanted into the fractured bone 300, the screw shaft 20 is threadedly coupled to the fractured bone 300, the screw head 10 is threadedly coupled to the bone plate 200, and the screw shaft 20 and the screw head 10 are coupled to each other by the fixing pin 30. When the soft tissue stress acts on the screw rod, because the space which allows the fixing pin 30 to deform is arranged in the screw rod, and the screw rod 20 can move relative to the screw head 10, the fixing pin 30 deforms under the stress action, and then the screw rod 20 can be driven to move relative to the screw head 10. It can be seen in fig. 8 that due to the deformation of the fixing pin 30, the screw shank 20 is moved relative to the screw head 10 such that the axes of the two no longer coincide. At this time, since the screw head 10 is fixedly connected to the bone plate 200 and the screw shaft 20 is fixedly connected to the fractured bone 300, the screw shaft 20 moves the fractured bone 300 relative to the bone plate 200. Typically, as shown, the screw shaft 20 moves relative to one another, thereby moving the fractured bones 300 relative to one another, resulting in a slight reduction in the fracture gap. As described in the background art, the relative movement of the fractured bone 300 and the bone plate 200 promotes callus formation and fracture healing during fracture healing, so that the dynamic locking screw 100 generates a micro-motion effect during use, so that the fractured bone 300 moves relative to the fracture plate, and callus formation and fracture healing can be promoted.

In practice, the required micro-motion direction of the dynamic locking screw 100 is circumferential, and in order to achieve the above purpose, in some embodiments of the present invention, the screw shaft 20 is connected to the screw head 10 by two fixing pins, and the axes of the two fixing pins are perpendicular to each other.

As shown in fig. 1 and 2, the two fixing pins are defined as a first fixing pin 310 and a second fixing pin 320, which are arranged in a staggered manner in the axial direction of the screw head 10 (which may be referred to as the screw shaft 20), that is, in a staggered manner in the axial direction, and in a phase difference of 90 ° in the circumferential direction of the screw head 10. As such, the first axis 311 of the first fixing pin 310 is perpendicular to the second axis 321 of the second fixing pin 320.

The axis of the first fixing pin 310 and the axis of the second fixing pin 320 are perpendicular to each other, and when the fine movement direction is along the axial direction of one of the fixing pins, the fixing pin is forced but not deformed, and only the other fixing pin is deformed. If the fine movement direction is along the axial direction of the first fixing pin 310, the first fixing pin 310 is not deformed, and the second fixing pin 320 is deformed. But when the micromotion direction is not along the axial or radial direction of either of the fixed pins, then both pins will be deformed. Therefore, the fixing pins are deformed regardless of the direction of the stress applied to the soft tissue, and a micro-motion effect is formed.

It is understood that in other embodiments, the axis of the first fixing pin 310 and the axis of the second fixing pin 320 may not be perpendicular to each other, as long as they are at an angle, i.e., they are out of phase in the circumferential direction of the screw head 10. Thus, the fixing pin can deform according to the stress, and a micro-motion effect is achieved. In other embodiments, 3 or more than 3 fixing pins may be provided in one dynamic locking screw 100, and if they are staggered in the axial height and in the circumferential direction, the deformation of the fixing pins can be realized, resulting in a micro-motion effect.

In some embodiments, referring to fig. 3 and 4, the screw head 10 includes a threaded portion 110 having an external thread, and a shaft sleeve 120 connected to the threaded portion 110, an end surface of the shaft sleeve 120 away from the threaded portion 110 is opened with a connection hole 130, an outer wall of the connection hole 130 is opened with a first pin hole 140 and a second pin hole 150 arranged along an axial direction of the connection hole 130, and the first pin hole 140 and the second pin hole 150 are arranged at an angle of 90 ° offset in a circumferential direction of the connection hole 130 such that an axis of the first pin hole 140 is perpendicular to an axis of the second pin hole 150. The axis of the boss 120 coincides with the axis of the threaded portion 110. The connection between the sleeve 120 and the threaded portion 110 is not limited, and may be formed integrally, screwed, welded, or the like. The external threads on threaded portion 110 may be tapered threads, cylindrical threads, or both. The threaded portion 110 is adapted to be fixedly coupled to internal threads of the bone plate 200.

Referring to fig. 6 and 7, the screw rod 20 includes a screw shaft 210, a polish rod 220 connected to the screw shaft 210, wherein the screw shaft 210 has an external thread, the polish rod 220 is formed with a third pin hole 230 and a fourth pin hole 240 arranged along an axial direction of the polish rod 220, the polish rod 220 is inserted into the connection hole 130 and is in clearance fit with the connection hole 130, the third pin hole 230 is fitted with the first pin hole 140, and the fourth pin hole 240 is fitted with the second pin hole 150. The third pin hole 230 and the fourth pin hole 240 may have a cylindrical shape, a prismatic shape, or the like, but preferably have a cylindrical shape in the middle and a flared shape with a diameter gradually increasing toward the ends, as shown in fig. 2. The pin hole increases the movable length range of the fixing pin, and the fixing pin is convenient to deform. Further, the end of the nail shaft 210 far away from the polish rod 220 is further provided with a chamfer 211, and the chamfer 211 can facilitate the insertion of the nail shaft 210 into the fractured bone 300. The number of chamfers 211 is not limited.

The fixing pins 30 include a first fixing pin 310 and a second fixing pin 320, wherein the first fixing pin 310 connects the first pin hole 140 and the third pin hole 230, the first fixing pin 310 is tightly fitted with the first pin hole 140, the first fixing pin 310 is in clearance fit with the third pin hole 230, the second fixing pin 320 connects the second pin hole 150 and the fourth pin hole 240, the second fixing pin 320 is tightly fitted with the second pin hole 150, and the second fixing pin 320 is in clearance fit with the fourth pin hole 240. Specifically, when the arrangement is performed, the first fixing pin 310 and the second fixing pin 320 are both cylindrical, and as shown in fig. 5, the structure of the first fixing pin 310 is specifically a cylindrical pin; the second fixing pin 320 has the same structure as the first fixing pin 310. The first fixing pin 310 has an outer diameter slightly smaller than the inner diameter of the third pin hole 230, and the second fixing pin 320 has an outer diameter slightly smaller than the inner diameter of the fourth pin hole 240. However, it should be noted that the structure of the first fixing pin 310 and the second fixing pin 320 is not limited as long as both the first fixing pin 310 and the second fixing pin 320 can be deformed by stress.

After the screw head 10 and the screw rod 20 are connected by the first fixing pin 310 and the second fixing pin 320, the axis of the polish rod 220 coincides with the axis of the connecting hole 130, the first axis 311 of the first fixing pin 310 is perpendicular to the second axis 321 of the second fixing pin 320, and both the first fixing pin 310 and the second fixing pin 320 can deform under the action of stress, so that the requirement of circumferential micro-motion can be met.

In specific implementation, the sizes of the first pin hole 140, the second pin hole 140, the third pin hole 230, and the fourth pin hole 240 are set to be identical, and the sizes of the first fixing pin 310 and the second fixing pin 320 are set to be identical. When the screw head 10 and the screw shaft 20 are connected by the first fixing pin 310 and the second fixing pin 320, the first fixing pin 310 and the second fixing pin 320 can be used as they are, and the versatility is good.

It is to be understood that in other embodiments, the sizes of the first pin hole 140, the second pin hole 150, the third pin hole 230, and the fourth pin hole 240 may be different, and the sizes of the first fixing pin 310 and the second fixing pin 320 may be different, provided that the first fixing pin 310 and the second fixing pin 320 are both capable of deforming under stress. For example, the inner diameter of the first pin hole 140 is smaller than the inner diameter of the second pin hole 150, and the outer diameter of the first fixing pin 310 is smaller than the inner diameter of the second fixing pin 320.

In the above embodiment, the connection hole 130 is specifically configured as a blind hole, and the inner diameter thereof is larger than the outer diameter of the polish rod 220 of the screw rod 20. The end surface of the shaft sleeve 120 far away from the threaded portion 110 is provided with a blind hole, and the end surface of the screw head 10 far away from the shaft sleeve 120 does not need to be changed in structure, and the end surface of the screw head 10 can be normally provided with a cross groove, an inner hexagonal groove and other structures so as to be matched with a wrench. In other embodiments, the connecting hole 130 may be a stepped through hole, for example, the inner diameters of two ends of the through hole are different, so as to meet the requirements of matching with the polish rod 220 and matching with a wrench.

Further, the boss 120 is cylindrical, and the coupling hole 130 is formed in a circular shape in cross section. After the polish rod 220 is inserted into the connection hole 130, the axis of the polish rod 220 coincides with the axis of the connection hole 130, and the distance of the polish rod 220 jogging is consistent in the circumferential direction when the fixing pin 30 is deformed, thereby realizing uniform jogging. And, the appearance of axle sleeve 120 sets up to be cylindrical, and connecting hole 130 is the circular port, and then all wall thickness of pore wall is unanimous, and axle sleeve 120 structural strength is even, is difficult to the fracture. The shape of the connection hole 130 is not limited to the above-described circular shape, but may be other shapes such as a polygonal shape in cross section.

In some embodiments, the fixing pin 30 penetrates the screw head 10, and both ends of the fixing pin 30 are exposed to the outer surface of the shaft sleeve 120. In specific implementation, the first pin hole 140 and the second pin hole 150 both penetrate through the shaft sleeve 120 along the radial direction of the shaft sleeve 120; the third pin hole 230 and the fourth pin hole 240 both penetrate through the polish rod 220 along the radial direction of the polish rod 220, and after the screw head 10 and the screw rod 20 are connected by the first fixing pin 310 and the second fixing pin 320, both ends of the first fixing pin 310 are exposed on the outer surface of the shaft sleeve 120, and both ends of the second fixing pin 320 are also exposed on the outer surface of the shaft sleeve 120. Thus, both ends of the first fixing pin 310 are fixedly connected with the screw head 10, and the fixing is reliable. Similarly, the two ends of the second fixing pin 320 are fixedly connected with the screw head 10, and the fixing is reliable.

In a preferred embodiment, the first fixing pin 310 is connected to the bushing 120, more specifically, the first pin hole 140, at both ends thereof by welding. The size of the first fixing pin 310 may be set to be slightly smaller than the size of the first pin hole 140 by welding, so as to facilitate the insertion of the first fixing pin 310. Similarly, the two ends of the second fixing pin 320 are connected to the screw head 10 by welding, and the size of the second fixing pin 320 may be slightly smaller than the size of the second pin hole 150, so as to facilitate the insertion of the second fixing pin 320.

In a specific embodiment, both ends of the fixing pin 30 are disposed not higher than the outer surface of the sleeve 120. More specifically, both ends of the first fixing pin 310 are integrated with the outer surface of the sleeve 120 or slightly lower than the outer surface of the sleeve 120; both ends of the second fixing pin 320 are integrated with the outer surface of the sleeve 120 or slightly lower than the outer surface of the sleeve 120. The two ends of the fixing pin 30 are not higher than the surface of the screw head 10, so that when the dynamic locking screw 100 is implanted into the fractured bone 300, the two fixing pins 30 do not interfere with the fractured bone 300, and the phenomenon that micro motion cannot be formed due to interference is avoided.

In other embodiments, the first pin hole 140 and the second pin hole 150 both extend along the radial direction of the sleeve 120 but do not extend through the sleeve 120, and the first pin hole 140 and the second pin hole 150 are both blind holes. After the screw head 10 and the screw shaft 20 are connected by the first fixing pin 310 and the second fixing pin 320, one end of the first fixing pin 310 is inserted into the first pin hole 140, the other end is fixedly connected to the first pin hole 140, one end of the second fixing pin 320 is inserted into the second pin hole 150, and the other end is fixedly connected to the second pin hole 150.

In addition to the above embodiments, the axis of the fixation pin 30 extends in the radial direction of the screw shaft 20. In specific implementation, the first pin hole 140 and the second pin hole 150 both penetrate through the shaft sleeve 120 along the radial direction of the shaft sleeve 120; the third pin hole 230 and the fourth pin hole 240 both penetrate through the polish rod 220 in the radial direction of the polish rod 220, the four pin holes are arranged in the radial direction to facilitate processing, and when the first fixing pin 310 and the second fixing pin 320 are used for connecting the screw head 10 and the screw rod 20, the first fixing pin 310 and the second fixing pin 320 are relatively convenient to align and assemble. However, it should be noted that in other embodiments, the fixing pin 30 may be disposed obliquely, i.e. the first fixing pin 310 and the second fixing pin 320 are not perpendicular to the axial direction of the shaft sleeve 120, and the implementation of the micro-motion effect is not affected.

As shown in fig. 8, an embodiment of the present invention further provides a dynamic locking bone plate system, comprising a bone plate 200 and the dynamic locking screw 100 of any of the previous embodiments, wherein the screw head 10 is threadedly connected to the bone plate 200, and the screw shaft 20 is threadedly connected to the broken bone 300. The bone plate 200 is overlapped on two bone fragments 300, and each bone fragment 300 is connected with the bone plate 200 through a dynamic locking screw 100.

In FIG. 8, the dynamic locking screw 100 is shown with the fixation pin 30 portion, i.e., the boss 120, partially inserted into the fractured bone 300; in other embodiments, the sleeve 120 of the dynamic locking screw 100 may also be fully advanced into the fractured bone 300. As can be appreciated, the outer diameter of the collar 120 of the dynamic locking screw 100 is less than the inner diameter of the threaded bore in the fractured bone 300, i.e., less than the minor diameter of the screw shaft 20. On the basis, if the shaft sleeve 120 is provided with threads, the realization of the micro-motion effect is not influenced. In addition, the portion of the dynamic locking screw 100 provided with the fixation pin 30 may also be located entirely between the fractured bone 300 and the bone plate 200.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. A dynamic locking screw, comprising:

a screw head;

the screw rod, one end of the screw rod is inserted in the screwhead and is in clearance fit with the screwhead, the screw rod with be connected through the fixed pin between the screwhead, wherein the fixed pin with screwhead fastening connection, the fixed pin with leave the clearance between the screw rod.

2. The dynamic locking screw according to claim 1, wherein the screw shaft and the screw head are connected by two or more fixing pins, the two or more fixing pins are offset in the axial direction of the screw shaft, and the axes of the two or more fixing pins are offset in phase in the circumferential direction of the screw head.

3. The dynamic locking screw of claim 2, wherein the shaft and the head are connected by two fixing pins, the two fixing pins are offset in the axial direction of the shaft, and the axes of the two fixing pins are perpendicular to each other.

4. The dynamic locking screw according to claim 3, wherein the screw head comprises a threaded portion and a shaft sleeve connected with the threaded portion, a connecting hole is formed in an end face, far away from the threaded portion, of the shaft sleeve, a first pin hole and a second pin hole are formed in a hole wall of the connecting hole, the first pin hole and the second pin hole are arranged in the axial direction of the connecting hole, and the axis of the first pin hole is perpendicular to the axis of the second pin hole;

the screw rod comprises a screw shaft and a polished rod connected with the screw shaft, wherein the screw shaft is provided with external threads, the polished rod is provided with a third pin hole and a fourth pin hole which are arranged along the axial direction of the polished rod, the polished rod is inserted into the connecting hole and is in clearance fit with the connecting hole, the third pin hole is matched with the first pin hole, and the fourth pin hole is matched with the second pin hole;

the fixing pins comprise a first fixing pin and a second fixing pin, wherein the first fixing pin is connected with the first pin hole and the third pin hole, the first fixing pin is in fastening fit with the first pin hole, the first fixing pin is in clearance fit with the third pin hole, the second fixing pin is connected with the second pin hole and the fourth pin hole, the second fixing pin is in fastening fit with the second pin hole, and the second fixing pin is in clearance fit with the fourth pin hole.

5. The dynamic locking screw of claim 4, wherein the third and/or fourth pin holes are shaped: the middle part is cylindrical, and the two ends are horn-shaped with the diameter gradually enlarged to the end parts.

6. The dynamic locking screw of claim 4, wherein the first and/or second pin holes are blind holes or through holes and the third and fourth pin holes are through holes.

7. The dynamic locking screw of claim 4, wherein the fixation pin extends through the screw head, and both ends of the fixation pin are exposed at the outer surface of the sleeve.

8. The dynamic locking screw of claim 7, wherein neither end of the fixation pin is raised above the outer surface of the boss.

9. The dynamic locking screw of claim 2 or 3, wherein both ends of the fixing pin and the screw head are welded together, respectively.

10. A dynamic locking bone plate system comprising a bone plate, further comprising a dynamic locking screw as claimed in any one of claims 1 to 9.

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