Screw drive module and intervertebral fusion cage including the same

Abstract

A screw driving module and an intervertebral body fusion cage including the same are disclosed. The screw driving module according to an embodiment of the present invention may include a screw including a screw head and a screw body extending from the screw head and having a screw thread on an outer peripheral surface, a housing in which the screw head is rotatably accommodated, and a limit torque setting member disposed in the housing, which prevents the screw head from rotating when a torque less than a limit torque set for the screw head is applied, and allows the screw head to rotate when a torque equal to or greater than the limit torque is applied.

Description

Technical Field

[0001] The present invention relates to a screw drive module and an intervertebral fusion cage including the same, and more particularly, to a screw drive module applicable to an implant that requires in-vivo expansion and an intervertebral fusion cage including the same.

Background Art

[0002] Generally, an implant that requires in-vivo expansion is provided with a drive system for expansion. As a driving method of such a drive system, a screw drive method is often adopted. For example, an expandable intervertebral fusion cage having a structure in which a plate can be displaced upward or downward by rotation of a screw in the body has been disclosed.

[0003] Most conventional screw drive structures do not have another configuration for preventing loosening of the screw, and only provide the pressure applied to the implant in the body as the sole fixing means. As a result, when a patient with the implant is subjected to an impact above a certain level due to an accident or the like, or when continuous fatigue accumulates on the implant during the life process of the patient after implant transplantation, there may occur a problem that the expansion state of the implant collapses while the screw loosens. In order to solve such a problem, development of a structure for preventing loosening of the screw is required so that an implant expanded in the body by a screw drive method can stably maintain the expanded state after transplantation.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention is for solving the problems of the above-described prior art, and an object of the present invention is to provide a screw drive module that prevents unintentional loosening of a screw by adding a mechanical minimum threshold torque to the screw drive, and an intervertebral body fusion cage including the same.

[0006] The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from the following description.

Means for Solving the Problems

[0007] According to one aspect of the present invention, there is provided a screw drive module including a screw including a screw head and a screw body extending from the screw head and having a thread on an outer peripheral surface, a housing in which the screw head is rotatably accommodated, and a limit torque setting member disposed in the housing and preventing rotation of the screw head with respect to a torque less than a limit torque set for the screw head and allowing rotation of the screw head when a torque equal to or greater than the limit torque is applied.

[0008] In the screw drive module according to an embodiment of the present invention, the screw head has one or more first grooves on an outer peripheral surface, and the limit torque setting member, in a state of being inserted into the first groove of the screw head, prevents rotation of the screw head before a set limit torque is applied, and when a torque equal to or greater than the limit torque is applied, can disengage from the first groove and allow rotation of the screw head.

[0009] In the screw drive module according to an embodiment of the present invention, the first groove may be formed along the longitudinal direction of the screw.

[0010] In the screw drive module according to an embodiment of the present invention, a plurality of the first grooves may be arranged at regular intervals along the circumferential direction of the screw head.

[0011] In a screw drive module according to an embodiment of the present invention, the limit torque setting member may include a member body disposed so as to surround at least a part around the screw head, and a locking portion protruding from the member body toward the screw head so as to be inserted into the first groove.

[0012] In a screw drive module according to an embodiment of the present invention, the screw head further includes a second groove continuously recessed along the circumferential direction, and the screw drive module may further include a detachment prevention member fixedly disposed in the housing in a state of being inserted into a part of the second groove to prevent the screw from detaching from the housing.

[0013] In a screw drive module according to an embodiment of the present invention, the deviation prevention member may be formed in a pin shape and disposed perpendicular to the screw.

[0014] According to another aspect of the present invention, a screw drive module includes a screw including a screw head and a screw body extending from the screw head and having a thread on an outer peripheral surface, a housing in which the screw head is rotatably accommodated, and a limit torque setting member disposed in the housing, which prevents rotation of the screw head with respect to a torque less than a limit torque set for the screw head and allows rotation of the screw head when a torque equal to or greater than the limit torque is applied, a guide member to which the screw body of the screw is threadably coupled, and one or more plates movably connected to the housing and displaced by relative movement between the screw drive module and the guide member, and when the screw rotates, a vertebral body fusion cage is provided in which the screw drive module moves relative to the guide member forward or backward and the plate is displaced by the guide member.

[0015] In a vertebral body fusion cage according to an embodiment of the present invention, the guide member includes a guide body formed to penetrate vertically, and the screw drive module may be disposed inside the guide body.

[0016] In the vertebral body fusion cage according to an embodiment of the present invention, the guide member is provided with a screw hole formed in the front, and the screw body of the screw can be screwed into the screw hole.

[0017] In the vertebral body fusion cage according to an embodiment of the present invention, the guide member further includes a rear hole formed to penetrate rearward in communication with the guide body, and a driving tool passing through the rear hole can reach the screw head.

[0018] In the vertebral body fusion cage according to an embodiment of the present invention, the housing is provided with a first connecting portion formed in the vertical direction, and the plate can be provided with a second connecting portion movably connected to the first connecting portion in the vertical direction.

[0019] In the vertebral body fusion cage according to an embodiment of the present invention, the screw head has one or more first grooves on the outer peripheral surface, and the limit torque setting member, in a state of being inserted into the first groove of the screw head, prevents the rotation of the screw head before the set limit torque is applied, and when a torque equal to or greater than the limit torque is applied, it can disengage from the first groove and allow the rotation of the screw head.

[0020] In the vertebral body fusion cage according to an embodiment of the present invention, the first groove can be formed along the longitudinal direction of the screw.

[0021] In the vertebral body fusion cage according to an embodiment of the present invention, a plurality of the first grooves can be arranged at regular intervals along the circumferential direction of the screw head.

[0022] In the vertebral body fusion cage according to an embodiment of the present invention, the limit torque setting member can include a member body disposed to surround at least a part around the screw head, and a locking portion protruding from the member body toward the screw head so as to be inserted into the first groove.

[0023] In the vertebral body fusion cage according to an embodiment of the present invention, the screw head further includes a second groove continuously recessed along the circumferential direction, and a detachment prevention member that is fixedly arranged in the housing in a state of being inserted into a part of the second groove and prevents the screw from detaching from the housing can be further included.

[0024] In the vertebral body fusion cage according to an embodiment of the present invention, the detachment prevention member is formed in a pin shape and can be arranged perpendicular to the screw.

[0025] In the vertebral body fusion cage according to an embodiment of the present invention, the guide member further includes side guide portions formed in the front-rear direction on both side walls of the guide body, and the detachment prevention member is arranged to penetrate both sides of the housing, and one end portion and the other end portion can be seated on the side guide portions respectively.

Advantages of the Invention

[0026] According to an embodiment of the present invention, by adding a mechanically minimum threshold torque to the screw drive by the limit toggle setting member, it is possible to prevent the unintentional loosening of the screw in the screw drive module, and after the expandable vertebral body fusion cage is transplanted into the patient's body through the screw drive module having such a structure, the expanded state can be stably maintained.

[0027] The effects of the present invention are not limited to the above effects, and it should be understood that the effects include all effects inferable from the configuration of the invention described in the detailed description or claims of the present invention.

Brief Description of the Drawings

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Figure 2

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Figure 8

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[0037]

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[0038]

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[0040]

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[0042]

Figure 15

Mode for Carrying Out the Invention

[0043] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them. The present invention can be implemented in various different forms and is not limited to the embodiments described in this specification. In the drawings, in order to clearly explain the present invention, parts not related to the explanation are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0044] The words and terms used in this specification and the claims are not limited to their ordinary or dictionary meanings, and must be interpreted as meanings and concepts that conform to the technical idea of the present invention in accordance with the principle that the inventor can define terms and concepts in order to best explain his own invention.

[0045] In this specification, terms such as "including" or "having" are intended to describe the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should not be construed as precluding the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0046] When a component is "in front of", "behind", "lateral to", "above", or "below" another component, unless there are special circumstances, it not only means being directly in contact with the other component and being arranged "in front of", "behind", "lateral to", "above", or "below", but also includes the case where other components are arranged in between. Also, when a component is "connected" to another component, unless there are special circumstances, it not only means being directly connected to each other, but also includes the case of being indirectly connected to each other.

[0047] Hereinafter, a screw drive module according to an embodiment of the present invention will be described with reference to the drawings.

[0048] FIG. 1 is a front perspective view of a screw drive module according to an embodiment of the present invention, and FIG. 2 is a rear perspective view of a screw drive module according to an embodiment of the present invention. Also, FIG. 3 is a view showing the housing of the screw drive module according to an embodiment of the present invention transparently, and FIG. 4 is an exploded perspective view of the screw drive module according to an embodiment of the present invention.

[0049] A screw drive module 100 according to an embodiment of the present invention provides a driving force by the rotation of a screw. For example, the screw drive module 100 can move relatively forward or backward in relation to an object meshed with the screw when the screw rotates.

[0050] Referring to FIGS. 1 to 4, a screw drive module 100 according to an embodiment of the present invention can include a screw 110, a housing 120, a limit torque setting member 130, and a deviation prevention member 140.

[0051] The screw 110 includes a screw head 111 and a screw body 112 extending from the screw head 111 and having a thread 112a on the outer peripheral surface. The screw 110 is rotatably disposed in the housing 120 and is screwed to a counterpart (not shown). When the screw 110 rotates, the housing 120 and the counterpart can move relative to each other such that the distance between the housing 120 and the counterpart approaches or separates along the longitudinal direction of the screw 110.

[0052] The screw head 111 has one or more first grooves 111a on the outer peripheral surface. The first groove 111a can be formed along the longitudinal direction of the screw 110. Also, a plurality of the first grooves 111a can be arranged at regular intervals along the circumferential direction of the screw head 111. Further, a first protrusion 111b that protrudes relatively outward in the radial direction compared to the first groove 111a is formed between adjacent first grooves 111a.

[0053] In one embodiment of the present invention, the screw head 111 can further include a second groove 111c that is continuously recessed along the circumferential direction. The second groove 111c is formed so that a detachment prevention member 140 can be inserted. On the other hand, the screw head 111 can be provided with a drive tool coupling portion 111d for coupling a drive tool (not shown) at an end in the opposite direction to the portion where the screw body 112 extends.

[0054] The screw body 112 is connected to the screw head 111 and has a thread 112a on the outer peripheral surface. The thread 112a of the screw body 112 meshes with the counterpart and transmits the rotational force of the screw to the counterpart when the screw 110 rotates. The rotational force of the screw transmitted to the counterpart is converted into a driving force for linear displacement between the housing 120 and the counterpart.

[0055] The housing 120 rotatably accommodates the screw head 111. When the screw body 112 of the screw 110 is screwed to a counterpart (not shown) and screw rotation is generated by a drive tool (not shown) coupled to the screw head 111, the housing 120 and the counterpart approach or separate from each other.

[0056] In one embodiment of the present invention, the housing 120 can include a housing body 121, a screw head arrangement portion 122, a limit torque setting member arrangement portion 123, and a deviation prevention member arrangement portion 124.

[0057] The housing body 121 can have various shapes on the premise that the screw head 111 can be accommodated. In one embodiment of the present invention, the housing body 121 has a square box shape.

[0058] The screw head arrangement portion 122 is formed to penetrate the housing body 121 in the front - rear direction. Thereby, with the screw head 111 arranged in the screw head arrangement portion 122, a driving tool for rotating the screw head 111 can be coupled to the screw head 111, and the screw body 112 can protrude forward of the housing body 121.

[0059] The limit torque setting member arrangement portion 123 is formed on the housing body 121 so that the limit torque setting member 130 can be arranged. In one embodiment of the present invention, the limit torque setting member arrangement portion 123 is formed in a shape that wraps at least a part of the screw head arrangement portion 122. More specifically, the limit torque setting member arrangement portion 123 has a slot shape that penetrates both sides so that the limit torque setting member 130 can penetrate the side surface of the housing body 121 and be arranged.

[0060] The deviation prevention member arrangement portion 124 is formed on the housing body 121 so that the deviation prevention member 140 can be arranged. In one embodiment of the present invention, the deviation prevention member arrangement portion 124 is formed as a through - hole that penetrates both sides of the housing body 121, but is formed so that at least a part of the deviation prevention member 140 can be inserted into the second groove 112c of the screw head 111.

[0061] The limit torque setting member 130 is disposed in the housing 120, and prevents rotation of the screw head 111 with respect to a torque less than the limit torque set for the screw head 111, and allows rotation of the screw head 111 when a torque equal to or greater than the limit torque is applied. The limit torque setting member 130 suppresses rotation of the screw head 111 before the set limit torque is applied while being inserted into the first groove 111a of the screw head 111, and allows rotation of the screw head 111 by disengaging from the first groove 111a when a torque equal to or greater than the limit torque is applied.

[0062] In one embodiment of the present invention, the limit torque setting member 130 can include a member body 131 disposed so as to surround at least a part around the screw head 111, and a locking portion 132 protruding from the member body 131 toward the screw head 111 so as to be inserted into the first groove 111a. More specifically, the member body 131 is disposed so as to wrap around about half of the screw head 111 along the circumferential direction, and the locking portion 132 can protrude from one end portion of the member body 131 toward the screw head 111. The locking portion 132 restricts rotation of the screw head 111 until a torque equal to or greater than the limit torque acts on the screw 110 while being inserted into the first groove 111a, and can be pressed by the adjacent first protrusion 111b and disengaged from the first groove 111a when a torque equal to or greater than the limit torque acts on the screw 110. In relation to this, when a torque equal to or greater than the limit torque is applied to the screw 110, the member body 131 can be elastically deformed.

[0063] The detachment prevention member 140 is fixedly disposed in the housing 120 while being inserted into a part of the second groove 111c, and prevents the screw 110 from detaching from the housing 120. In one embodiment of the present invention, the deviation prevention member 140 can be formed in a pin shape. More specifically, the detachment prevention member 140 can have at least a part inserted into the second groove 112c of the screw head 111 while being inserted into a detachment prevention member arrangement portion 124 formed as a through hole penetrating both sides of the housing body 121. Further, the detachment prevention member 140 can be disposed perpendicular to the screw 110.

[0064] FIG. 5 is a perspective view of an intervertebral fusion cage according to an embodiment of the present invention, and FIG. 6 is a perspective view of the intervertebral fusion cage according to an embodiment of the present invention shown from another direction. Further, FIG. 7 is an exploded perspective view of the intervertebral fusion cage according to an embodiment of the present invention.

[0065] The intervertebral fusion cage 1000 according to an embodiment of the present invention is a device used in a fusion, which is a surgical treatment method for spinal diseases. The intervertebral fusion cage 1000 according to an embodiment of the present invention includes a screw drive module 1100 as a drive system. Further, the intervertebral fusion cage 1000 according to an embodiment of the present invention is inserted between vertebrae from which a degenerated intervertebral disc has been removed and serves to support between vertebral bodies until the vertebrae fuse. The intervertebral fusion cage 1000 according to an embodiment of the present invention enables both the lordosis and height of the spine to be ensured.

[0066] Referring to FIGS. 5 to 7, the intervertebral fusion cage 1000 according to an embodiment of the present invention can include a screw drive module 1100, a guide member 1200, and a plate 1300.

[0067] The screw drive module 1100 moves relative to the guide member 1200 by the rotation of the screw 1110 and causes displacement of the plate 1300. The screw drive module 1100 can include a screw 1110, a housing 1120, a limit torque setting member 1130, and a deviation preventing member 1140.

[0068] The screw 1110 includes a screw head 1111 and a screw body 1112 that extends from the screw head 1111 and has a thread 1112a on the outer peripheral surface.

[0069] The screw head 1111 has one or more first grooves 1111a on its outer peripheral surface. The first grooves 1111a can be formed along the longitudinal direction of the screw 1110. Also, a plurality of the first grooves 1111a can be arranged at regular intervals along the circumferential direction of the screw head 1111. On the other hand, between adjacent first grooves 1111a, a first protrusion 1111b that protrudes relatively outward in the radial direction compared to the first grooves 1111a is formed.

[0070] Further, the screw head 1111 can further include a second groove 1111c that is continuously recessed along the circumferential direction. The second groove 1111c is formed so that a detachment prevention member 1140 can be inserted.

[0071] The screw body 1112 is connected to the screw head 1111 and has a thread 1112a on its outer peripheral surface. The thread 1112a of the screw body 1112 meshes with the guide member 1200 and transmits the rotational force of the screw to the guide member 1200 when the screw 1110 rotates. The rotational force of the screw transmitted to the guide member 1200 is converted into a driving force for linear displacement between the housing 1120 and the guide member 1200.

[0072] The housing 1120 rotatably accommodates the screw head 1111. When the screw body 1112 of the screw 1110 is screw-coupled to the guide member 1200 and screw rotation occurs by a driving tool (not shown) coupled to the screw head 1111, the housing 1120 and the guide member 1200 approach each other or move away from each other.

[0073] In the intervertebral body fusion cage 1000 according to an embodiment of the present invention, the housing 1120 can include a housing body 1121, a screw head arrangement portion 1122, a limit torque setting member arrangement portion 1123, a detachment prevention member arrangement portion 1124, a guide hole 1125, a first connection portion 1126, and a plate portion 1127.

[0074] The housing body 1121 has a box shape that penetrates vertically. The vertically penetrating portion of the housing body 1121 can be filled with a bone graft material. The left - right width of the housing body 1121 can correspond to the left - right width of the vertically penetrating portion of the guide body 1210 of the guide member 1200 described later.

[0075] The screw - head placement portion 1122 is formed by penetrating the housing body 1121 in the front - rear direction. More specifically, the screw - head placement portion 1122 is formed by penetrating the front wall body 1121a of the housing body 1121 in the front - rear direction. With the screw head 1111 placed in the screw - head placement portion 1122, the screw body 1112 can protrude forward of the housing body 1121.

[0076] The limit - torque setting member placement portion 1123 is formed in the housing body 1121 so that the limit - torque setting member 1130 can be placed. More specifically, the limit - torque setting member placement portion 1123 can be formed on the front wall body 1121a of the housing body 1121. In one embodiment of the present invention, the limit - torque setting member placement portion 1123 is formed in a shape that wraps around the screw - head placement portion 1122 along the circumferential direction. Also, the limit - torque setting member placement portion 1123 has a slot shape that penetrates both sides so that the limit - torque setting member 1130 can penetrate and be placed on the side surface of the front wall body 1121a of the housing body 1121.

[0077] The detachment - prevention member placement portion 1124 is formed in the housing body 1121 so that the detachment - prevention member 1140 can be placed. In one embodiment of the present invention, the deviation - prevention member placement portion 1124 is formed as a through - hole that penetrates both sides of the housing body 1121. More specifically, the detachment - prevention member placement portion 1124 penetrates both sides of the front wall body 1121a of the housing body 1121, but is formed so that at least a part of the detachment - prevention member 1140 can be inserted into the second groove 1111c of the screw head 1111.

[0078] The guide hole 1125 is formed by penetrating the rear wall 1121b of the housing body 1121 in the front-rear direction so that a driving tool (not shown) for rotating the screw can pass through the vertically penetrating portion of the housing body 1121 and reach the screw head 1111. The driving tool can reach the screw head 1111 through the guide hole 1125.

[0079] The first connecting portion 1126 is formed on the housing body 1121 so that the plate 1300 can be movably connected in the vertical direction. In one embodiment of the present invention, the first connecting portion 1126 is provided on the left and right side walls 1121c of the housing body 1121. The first connecting portion 1126 meshes with the second connecting portion 1340 of the plate 1300 described later. For example, the first connecting portion 1126 can include a groove shape recessed in the vertical direction.

[0080] The plate portion 1127 is connected to the lower side of the housing body 1121. The plate portion 1127 can be disposed opposite to the plate 1300 described later. The plate portion 1127 can extend forward, backward, and on both sides of the housing body 1121. Thereby, the plate portion 1127 can form the lower surface of the intervertebral body fusion cage 1000. On the other hand, the central portion of the plate portion 1127 can have a vertically penetrating shape so as to communicate with the vertically penetrating portion of the housing body 1121. Further, guide grooves 1127a may be provided on both sides of the plate portion 1127 so as to guide the insertion of the limit torque setting member 1130 into the limit torque setting member arrangement portion 1123 from the corners to the limit torque setting member arrangement portion 1123 side.

[0081] The limit torque setting member 1130 is disposed in the housing 1120, and prevents the rotation of the screw head 1111 with respect to a torque less than the limit torque set in the screw head 1111, and allows the rotation of the screw head 1111 when a torque equal to or greater than the limit torque is applied. In one embodiment of the present invention, the limit torque setting member 1130 suppresses the rotation of the screw head 1111 before the set limit torque is applied, while being inserted into the first groove 1111a of the screw head 1111, and when a torque equal to or greater than the limit torque is applied, it can be disengaged from the first groove 1111a by the adjacent first protrusion 1111b to allow the rotation of the screw head 1111.

[0082] The limit torque setting member 1130 may include a member body 1131 disposed so as to surround at least a part around the screw head 1111, and a locking portion 1132 protruding from the member body 1131 toward the screw head 1111 so as to be inserted into the first groove 1111a. For example, the member body 1131 may be disposed to wrap around about half of the screw head 1111 along the circumferential direction, and the locking portion 1132 may protrude from one end of the member body 1131 toward the screw head 1111. In this connection, when a torque equal to or greater than the limit torque is applied to the screw 1110, the member body 1131 may be elastically deformed.

[0083] The disengagement prevention member 1140 is fixedly disposed in the housing 1120 while being inserted into a part of the second groove 1111c, and prevents the screw 1110 from disengaging from the housing 1120. In one embodiment of the present invention, the deviation prevention member 1140 may be formed in a pin shape. More specifically, the disengagement prevention member 1140 may be inserted into a disengagement prevention member arrangement portion 1124 formed as a through hole penetrating both sides of the housing body 1121, and at least a part thereof may be inserted into the second groove 1111c of the screw head 1111. Further, the disengagement prevention member 1140 may be disposed perpendicular to the screw 1110.

[0084] FIG. 8 is a diagram showing a driving state of a screw drive module of an intervertebral body fusion cage according to an embodiment of the present invention.

[0085] Referring to FIG. 8, with the locking portion 1132 of the limit torque setting member 1130 inserted into the first groove 1111a, the rotation of the screw 1110 is restricted by the locking portion 1132 until a torque equal to or greater than the limit torque is applied. The protruding portion 1111b adjacent to the first groove 1111a into which the locking portion 1132 is inserted is locked to the locking portion 1132 to suppress the rotation of the screw. On the other hand, when a torque equal to or greater than the limit torque is applied to the screw 1110, the protruding portion 1111b of the screw head 1111 pushes the locking portion 1132 radially outward from the first groove 1111a. As a result, the screw 1110 rotates while the screw head 1111 rotates. The rotation of the screw 1110 can cause the behavior of the guide member 1200 engaged with the screw 1110.

[0086] The guide member 1200 is rotatably coupled to the screw body 1112 of the screw 1110. The guide member 1200 is displaced forward or backward relative to the screw drive module 1100, and the displacement of the plate 1300 is caused by the relative position change between the guide member 1200 and the screw drive module 1100. The guide member 1200 may include a guide body 1210, a front guide portion 1220, a rear guide portion 1230, a screw hole 1240, and a rear hole 1250.

[0087] The guide body 1210 is formed to penetrate vertically. The guide body 1210 can have a frame shape with a central portion penetrated. Also, the guide body 1210 can have a generally rectangular shape. The housing body 1121 of the housing 1120 of the screw drive module 1100 is disposed inside the guide body 1210, and the housing 1120 moves relative to the guide member 1200 within the guide body 1210 by the rotation of the screw 1110 rotatably coupled to the housing 1120. As described above, the vertically penetrating portion of the guide body 1210 can have a left-right width corresponding to the left-right width of the housing body 1211 of the housing 1120 of the screw drive module 1100.

[0088] The front guide portion 1220 is formed to be inclined at the front portion of the guide body 1210. The front guide portion 1220 guides the front guided portion 1320 of the plate 1300 when the guide member 1200 is displaced, and guides the upward movement of the front portion of the plate 1300. In one embodiment of the present invention, the front guide portion 1220 protrudes from the side walls of the front portion of the guide body 1210 to both sides, but is formed to have a predetermined angle so as to be inclined downward from the rear to the front side.

[0089] The rear guide portion 1230 is formed to be inclined at the rear portion of the guide body 1210. The rear guide portion 1230 guides the rear guided portion 1330 of the plate 1300 when the guide member 1200 is displaced. In other words, the upward movement of the rear portion of the plate 1300 is guided by the rear guide portion 1230. In one embodiment of the present invention, the rear guide portion 1230 protrudes from the side walls of the rear portion of the guide body 1210 to both sides, but is formed to have a predetermined angle so as to be inclined downward from the rear to the front side.

[0090] The screw hole 1240 may be formed in front of the guide body 1210. The screw hole 1240 may be formed to penetrate the front side wall of the guide body 1210 in the front-rear direction. The screw body 1112 of the screw 1110 of the screw drive module 1100 disposed on the guide body 1210 may be engaged with the screw hole 1240. Thereby, when the screw 1110 is driven, the guide member 1200 can move relative to the housing 1120 of the screw drive module 1100 forward or backward.

[0091] The rear hole 1250 is formed at the rear of the guide body 1210 in communication with the guide body 1210. More specifically, the rear hole 1250 may be formed to penetrate the rear side wall of the guide body 1210 in the front-rear direction. The rear hole 1250 allows a drive tool for driving the screw 1110 of the screw drive module 1100 to enter the inside of the guide body 1210. The drive tool that has entered the guide body 1210 through the rear hole 1250 can reach the screw 1110 by passing through the guide hole 1125 of the housing 1120.

[0092] The plate 1300 is movably connected to the housing 1120 and is displaced by the relative movement between the screw drive module 1100 and the guide member 1200. When the screw 1110 rotates, the screw drive module 1100 moves relative to the guide member 1200 forward or backward, and the plate 1300 can be displaced by the guide member 1200. Here, the displacement of the plate 1300 can mean that a part or the whole of the plate 1300 moves upward or downward.

[0093] The plate 1300 can form the anterior curvature angle and height of the intervertebral body fusion cage 1000. In one embodiment of the present invention, the plate 1300 forms the upper surface of the intervertebral body fusion cage 1000. The plate 1300 can include a plate body 1310, a front guided portion 1320, a rear guided portion 1330, and a second connecting portion 1340.

[0094] The plate body 1310 has an overall square shape and penetrates in the vertical direction. The plate body 1310 has side walls extending downward in four directions with respect to the penetrating portion.

[0095] The front guided portion 1320 is guided by the front guide portion 1220 of the guide member 1200. When the plate 1300 moves relative to the guide member 1200 and the front guided portion 1320 is guided by the front guide portion 1220, the front portion of the plate 1300 can rise. In one embodiment of the present invention, the front guided portion 1320 is recessed and formed on the inner surfaces of both side walls of the plate body 1310, but is recessed and formed in a shape inclined downward from the rear to the front side.

[0096] The rear guided portion 1330 is guided by the rear guide portion 1230 of the guide member 1200. When the plate 1300 moves relative to the guide member 1200 and the rear guided portion 1330 is guided by the rear guide portion 1230, the rear portion of the plate 1300 can rise. In one embodiment of the present invention, the rear guided portion 1330 is provided on the rear side wall of the plate body 1310 and is formed to incline downward from the rear to the front side.

[0097] The second connecting portion 1340 is movably connected to the first connecting portion 1126 in the vertical direction. The second connecting portion 1340 connects the plate 1300 to the housing 1120 of the screw drive module 1100. In one embodiment of the present invention, the second connecting portion 1340 can be movably connected to the first connecting portion 1126 of the housing 1120 in the vertical direction. In one embodiment of the present invention, the second connecting portion 1340 protrudes from the inner surfaces of both side walls of the plate body 1310 and can include a portion extending in the vertical direction.

[0098] Hereinafter, the operation of the intervertebral fusion cage 1000 according to one embodiment of the present invention will be described.

[0099] FIG. 9 is a perspective view of a state in which the angle of the plate of the intervertebral fusion cage according to one embodiment of the present invention is enlarged. FIG. 10 is a side view of a state in which the angle of the plate of the intervertebral fusion cage according to one embodiment of the present invention is enlarged, and FIG. 11 is a side sectional view showing the process in which the angles of the front guide portion and the front guided portion of the intervertebral fusion cage according to one embodiment of the present invention coincide.

[0100] Referring to FIGS. 9 to 11, when the screw 1110 of the screw drive module 1100 rotates in one direction with the plate 1300 not extended relative to the guide member 1200, the guide member 1200 moves forward relative to the screw drive module 1100 while the plate 1300 is displaced. At this time, the front portion of the plate 1300 is preferentially moved in the vertical direction, increasing the angle formed between the plate 1300 and the guide member 1200. In this connection, the rotation of the screw 1110 can be performed when a torque equal to or greater than the limit torque is applied to the screw.

[0101] As shown in FIG. 11, the angular expansion of the front portion of the plate 1300 is performed until the angle α formed by the front guided portion 1320 of the plate 1300 with respect to the ground is equal to the angle β formed by the front guide portion 1220 of the guide member 1200 with respect to the ground. The angle β formed by the front guide portion 1220 with respect to the ground in the non-expanded state of the plate 1300 is formed smaller than the angle α formed by the front guided portion 1320 of the plate 1300 with respect to the ground. Thereby, when the plate 1300 is displaced, the front portion of the plate 1300 rises until the angles formed by the front guide portion 1220 and the front guided portion 1320 with respect to the ground become equal, and an expansion of the lordosis angle may occur. In other words, the angle β formed by the front guide portion 1220 with respect to the ground can correspond to the lordosis angle of the spine that the intervertebral fusion cage 1000 can provide. On the other hand, as the front portion of the plate 1300 rises, the rear guided portion 1330 of the plate 1300 abuts against the rear guide portion 1230 of the guide member 1200 while the plate 1300 moves relatively rearward with respect to the guide member 1200.

[0102] In this way, at the initial stage of displacement of the plate 1300, the front portion of the plate 1300 rises until the angles formed by the front guide portion 1220 and the front guided portion 1320 with respect to the ground become equal. As a result, an expansion of the lordosis angle may occur. Through such a process, the intervertebral fusion cage 1000 can make the lordosis angle of the spine into a preset angle in a state where it is inserted into the intervertebral space of the patient.

[0103] FIG. 12 is a perspective view of a state in which the height of the plate of the vertebral body fusion cage according to an embodiment of the present invention has increased after angular expansion. FIG. 13 is a side view of a state in which the height of the plate of the vertebral body fusion cage according to an embodiment of the present invention has increased after angular expansion.

[0104] Referring to FIGS. 12 and 13, the front portion of the plate 1300 is raised to the maximum, and the angle formed by the front guided portion 1320 of the plate 1300 with respect to the ground is equal to the angle formed by the front guide portion 1220 of the guide member 1200 with respect to the ground. When the screw 1110 of the screw drive module 1100 rotates additionally in one direction in a state where the rear guided portion 1330 of the plate 1300 and the rear guide portion 1230 of the guide member 1200 are in contact with each other, the entire plate 1300 moves vertically while increasing in height. That is, after the angle increases by the set angle, when the screw 1110 rotates additionally, in a state where the front guided portion 1320 and the rear guided portion 1330 of the plate 1300 are in contact with the front guide portion 1220 and the rear guide portion 1230 of the guide member 1200, respectively, as the guide member 1200 moves forward relative to the screw drive module 1100, the plate 1300 moves vertically upward as a whole, whereby the height of the vertebral body fusion cage 1000 is expanded. At this time, the expansion height can be set according to the height of the intervertebral space that the vertebral body fusion cage 1000 is to secure. In this regard, the rotation of the screw 1110 can be performed when a torque equal to or greater than the limit torque is applied to the screw.

[0105] The displacement of the vertebral body fusion cage 1000 according to an embodiment of the present invention is reversible. In other words, when a torque equal to or greater than the limit torque is applied to the screw 1110 in the other direction in a state where the vertebral body fusion cage 1000 is expanded, the displacement of the guide member 1200 and the plate 1300 described above can proceed in the reverse direction.

[0106] On the one hand, in relation to the relative movement between the screw drive module 1100 and the guide member 1200, the guide member 1200 can further include side guide portions 1260 formed in the front - rear direction on both side walls of the guide body 1210. Also, the anti - detachment member 1140 is disposed through both sides of the housing 1120, and one end and the other end thereof can be seated on the side guide portions 1260, respectively.

[0107] In one embodiment of the present invention, the side guide portions 1260 can be provided at the corners of the upper ends of both side walls of the guide body 1210. Also, one end and the other end of the pin - shaped anti - detachment member 1140 protrude from both sides of the housing 1120 and can be guided by the side guide portions 1260 when the screw drive module 1100 moves relative to the guide member 1200.

[0108] FIG. 14 is a diagram showing the process in which the intervertebral body fusion cage according to one embodiment of the present invention is used in PLIF. FIG. 15 is a diagram showing the process in which the intervertebral body fusion cage according to one embodiment of the present invention is used in TLIF.

[0109] Referring to FIGS. 14 and 15, the intervertebral body fusion cage 1000 according to one embodiment of the present invention can be used for both PLIF (Posterior Lumbar Interbody Fusion) and TLIF (Transforaminal Lumbar Interbody Fusion). The intervertebral body fusion cage 1000 is inserted into the space between the upper vertebral body A1 and the lower vertebral body A2 to expand both the lordosis and the height. Also, by being expanded after being inserted into the patient's body, minimally invasive surgery during insertion is made possible.

[0110] Although one embodiment of the present invention has been described, the idea of the present invention is not limited by the embodiments presented in this specification. Those skilled in the art who understand the idea of the present invention can easily propose other embodiments by adding, changing, deleting, adding components, etc. within the scope of the same idea, and this is also within the scope of the idea of the present invention.

Claims

1. A screw including a screw head and a screw body extending from the screw head and having a thread on an outer peripheral surface, a housing in which the screw head is rotatably accommodated, a limit torque setting member disposed in the housing, preventing rotation of the screw head against a torque less than a limit torque set for the screw head, and allowing rotation of the screw head when a torque equal to or greater than the limit torque is applied, wherein the screw head has one or more first grooves on an outer peripheral surface, wherein the limit torque setting member, when inserted into the first groove of the screw head, prevents rotation of the screw head before the set limit torque is applied, and when a torque equal to or greater than the limit torque is applied, disengages from the first groove to allow rotation of the screw head, wherein the limit torque setting member includes a member body disposed so as to surround at least a part around the screw head, and a locking portion protruding from the member body toward the screw head so as to be inserted into the first groove, wherein when a torque equal to or greater than the limit torque is applied to the screw, the member body elastically deforms and the locking portion separates from the first groove, a screw drive module.

2. The screw drive module according to claim 1, wherein the first groove is formed along a longitudinal direction of the screw.

3. The screw drive module according to claim 1, wherein a plurality of the first grooves are arranged at regular intervals along a circumferential direction of the screw head.

4. wherein the screw head further includes a second groove continuously recessed along a circumferential direction, and further includes a detachment prevention member fixedly disposed in the housing in a state of being inserted into a part of the second groove, preventing the screw from detaching from the housing.

5. The screw drive module according to claim 4, wherein the detachment prevention member is formed in a pin shape and is disposed perpendicular to the screw.

6. A screw drive module including a screw including a screw head and a screw body extending from the screw head and having a thread on an outer peripheral surface, a housing in which the screw head is rotatably accommodated, and a limit torque setting member disposed in the housing, preventing rotation of the screw head against a torque less than a limit torque set for the screw head, and allowing rotation of the screw head when a torque equal to or greater than the limit torque is applied, A guide member to which the screw body of the screw is rotatably coupled; One or more plates movably coupled to the housing and displaced by relative movement between the screw drive module and the guide member; A vertebral body fusion cage in which when the screw rotates, the screw drive module moves relative to the guide member forward or backward, and the plate is displaced by the guide member; The screw head has one or more first grooves on its outer peripheral surface; The limit torque setting member, when inserted into the first groove of the screw head, prevents rotation of the screw head before the set limit torque is applied, and when a torque equal to or greater than the limit torque is applied, disengages from the first groove and allows rotation of the screw head; The limit torque setting member includes a member body disposed so as to surround at least a part around the screw head, and a locking portion protruding from the member body toward the screw head so as to be inserted into the first groove; When a torque equal to or greater than the limit torque is applied to the screw, the member body elastically deforms and the locking portion separates from the first groove; Vertebral body fusion cage.

7. The guide member includes a guide body formed to penetrate vertically; The screw drive module is disposed inside the guide body, and the vertebral body fusion cage according to claim 6;

8. The guide member includes a screw hole formed in the front; The screw body of the screw is screw-coupled to the screw hole, and the vertebral body fusion cage according to claim 7;

9. The guide member further includes a rear hole formed to penetrate rearward in communication with the guide body; The vertebral body fusion cage according to claim 7, wherein a drive tool passing through the rear hole can reach the screw head;

10. The housing includes a first connecting portion formed in the vertical direction, and the plate includes a second connecting portion movably connected to the first connecting portion in the vertical direction, and the vertebral body fusion cage according to claim 6;

11. The first groove is formed along the longitudinal direction of the screw, and the vertebral body fusion cage according to claim 6;

12. A plurality of the first grooves are arranged at regular intervals along the circumferential direction of the screw head, and the vertebral body fusion cage according to claim 11;

13. The screw head further includes a second groove continuously recessed along the circumferential direction; The intervertebral body fusion cage according to claim 7, further comprising a detachment prevention member that is fixedly disposed in the housing in a state of being inserted into a part of the second groove to prevent the screw from detaching from the housing.

14. The intervertebral body fusion cage according to claim 13, wherein the detachment prevention member is formed in a pin shape and is disposed perpendicular to the screw.

15. The guide member further includes side guide portions formed in the front-rear direction on both side walls of the guide body. The intervertebral body fusion cage according to claim 14, wherein the detachment prevention member is disposed through both sides of the housing, and one end portion and the other end portion are respectively seated on the side guide portions.

Images