Patent ID: 12251323

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily implement the present invention. However, the present invention may be implemented in various ways and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

In addition, the terms or words used in the specification and claims should not be construed as being limited to conventional or dictionary meanings, but should be interpreted as having meanings and concepts consistent with the technical spirit of the present invention based on the principle that the inventor may appropriately define concepts of the terms in order to describe his or her invention in the best mode.

FIGS.1A-1Bare views showing the overall appearance of a height-expandable spinal cage according to an embodiment of the present invention, andFIG.2is a view showing the exploded state of each component of the height-expandable spinal cage according to the embodiment of the present invention.

FIG.1Ais a view showing the state before the height of the height-expandable spinal cage according to the embodiment of the present invention is increased, andFIG.1Bis a view showing the state after the height of the height-expandable spinal cage according to the embodiment of the present invention is increased.

As shown inFIGS.1A-1B, the height-expandable spinal cage according to the present invention includes an upper plate100, a lower plate200, a frame300, a block400, and a driving bolt500.

The upper plate100is disposed at the upper portion of the frame300, and the lower plate200is disposed at the lower portion of the frame300. A plurality of teeth are formed on the upper surface of the upper plate100and the lower surface of the lower plate200. Here, the plurality of teeth dig into an upper vertebral body and a lower vertebral body so that the spinal cage has a constant fixing force between the vertebral bodies. The plurality of teeth allow the spinal cage to stably maintain the position thereof at the initial stage of spinal fusion procedures.

Each of the upper plate100and the lower plate200has a hollow formed therein. The hollow is filled with an autograft, allograft, or synthetic bone to accelerate bone growth.

In the embodiment, the upper plate100, the lower plate200, and the frame300are together formed in a long bullet shape in the forward-and-rearward direction, but are not limited thereto. The same may be formed in various shapes such as a flat shape, a curved shape, or a disk shape.

The frame300is disposed between the upper plate100and the lower plate200. Specifically, the frame300includes a front part310having a front hole311formed therein, a connection part320extending in the longitudinal direction from the rear end of the front part310, and a rear part330coupled to the rear end of the connection part320. A pair of connection parts320is provided, and an internal space321is defined between the pair of connection parts320in the longitudinal direction.

The block400is disposed between the upper plate100and the lower plate200, and may move in the longitudinal direction (the forward-and-rearward direction) in the internal space321defined by the pair of connection parts320of the frame300.

The driving bolt500has the rear end thereof connected to the block400, and may move in the forward-and-rearward direction to move the block400. The driving bolt500is formed of a bolt body510, having male threads511formed on the outer circumferential surface thereof, and a bolt head520formed at the end of the bolt body510, the bolt head520having a diameter larger than that of the bolt body510.

The front end of the bolt body510is rotatably inserted into the front hole311in the frame300to be movable forwards and rearwards, and the bolt head520is accommodated in the block400to pull the block400forwards and rearwards.

Normally, when the driving bolt500moves rearwards, the block400also moves rearwards, and the upper plate100and the lower plate200maintain a minimum height therebetween, as shown inFIG.1A.

After the height-expandable spinal cage is implanted into an affected area and the driving bolt500is moved forwards, the block400also moves forwards, thereby moving the upper plate100and the lower plate200forwards. Accordingly, as shown inFIG.1B, the distance between the upper plate100and the lower plate200is increased, thereby making it possible to increase the vertical distance between the vertebral bodies.

As described above, according to the present invention, the height-expandable spinal cage may be implanted into the affected area while occupying the minimum height thereof and may then be expanded between the vertebral bodies, thereby having an effect of being usefully used for minimally invasive surgery.

FIG.3is a view showing the block according to the embodiment of the present invention,FIG.4is a view sequentially showing a process in which the block according to the embodiment of the present invention is inserted into the frame,FIG.5is a view showing the state in which the height-expandable spinal cage according to the embodiment of the present invention is cut in the forward-and-rearward direction,FIG.6is a cross-sectional view of the height-expandable spinal cage according to the embodiment of the present invention, andFIGS.7A-7Bare views showing the state in which a restraint pin is inserted into the block according to the embodiment of the present invention.

As shown inFIG.3, the block400includes a block body410having a block hole411formed in the center thereof, an upper protrusion420protruding from one surface of the block body410toward the upper plate100, and a lower protrusion430protruding from the other surface of the block body410toward the lower plate200.

The block body410is formed in a hexahedral shape overall, and the block hole411is formed through the center of the block body410in the forward-and-rearward direction. The bolt head520of the driving bolt500is accommodated in the block hole411. A pair of upper protrusions420is formed on the upper surface of the block body410, and a pair of lower protrusions430is formed on the lower surface of the block body410.

A restraint groove440is formed at the side portion of the block body410. The restraint groove440is disposed between the upper protrusion420and the lower protrusion430, and has the connection part320of the frame300inserted thereinto and held therein. In the embodiment, a pair of restraint grooves440is provided.

As shown inFIG.4, the width between the pair of restraint grooves440formed in the respective side portions of the block body410is the same as the width of the internal space321between the pair of connection parts320, and the outermost widths of the upper protrusion420and the lower protrusion430are greater than the width of the internal space321between the pair of connection parts320. Accordingly, the block400may move in the forward-and-rearward direction without being separated from the internal space321between the pair of connection parts320.

A fusion passage460is perforated between the pair of upper protrusions420or between the pair of lower protrusions430. The fusion passage460provides a passage to allow autogenous bone, allograft bone, or synthetic bone to pass therethrough. The fusion passage460may be formed in the upper surface of the block body410, the lower surface thereof, or both the upper and lower surfaces thereof.

A round-shaped rotation-inducing part450is disposed between the block hole411and the restraint groove440in the block body410. The rotation-inducing part450is formed to be recessed into the side surface of the block body410, and connects the block hole411to the restraint groove440.

As shown inFIG.4, the block400is formed to have a length in the leftward-and-rightward direction greater than a length in the forward-and-rearward direction due to the upper protrusion420or the lower protrusion430.

Accordingly, in order to position the block400in the internal space321between the connection parts320of the frame300, first, the upper protrusion420and the lower protrusion430of the block400are disposed so as to be oriented in the longitudinal direction (the forward-and-rearward direction) (step1).

Then, the block400is inserted into the internal space321in the frame300so that the block400is disposed between the connection parts320(step2). The block400is rotated so that the upper protrusion420and the lower protrusion430are disposed orthogonal to the longitudinal direction (the leftward-and-rightward direction) (step3).

In this case, the rotation-inducing part450is in contact with the inner surface of the connection part320so that the connection part320is located in the restraint groove440between the upper protrusion420and the lower protrusion430. When the block400is completely rotated by 90 degrees, the connection part320of the frame300is inserted into and held in the restraint groove440.

As shown inFIGS.5and6, the upper plate100has an upper penetration part110formed therein and configured to allow the upper protrusion420to be inserted thereinto and accommodated therein, and the lower plate200has a lower penetration part210formed therein and configured to allow the lower protrusion430to be inserted thereinto and accommodated therein.

When the driving bolt500rotates and moves forwards and rearwards, the block400coupled to the rear end of the driving bolt500also moves forwards and rearwards. In this case, since the upper protrusion420and the lower protrusion430are inserted into and accommodated in the upper penetration part110and the lower penetration part210, respectively, the upper plate100and the lower plate200may be pulled forwards and rearwards together with the block400.

The upper penetration part110and the lower penetration part210are disposed to be orthogonal to the longitudinal direction (the forward-and-rearward direction) of the frame300, and the upper protrusion420and the lower protrusion430are also disposed to be orthogonal to the longitudinal direction of the frame300.

FIG.7Ais a view showing the state in which a restraint pin is coupled to the block according to the embodiment of the present invention, andFIG.7Bis a view showing the state in which the restraint pin according to the embodiment of the present invention is inserted into a long hole.

As shown in the drawings, a restraint pin470is formed at the side portion of the upper protrusion420or the lower protrusion430so as to protrude toward the outside of the frame300. A long hole120or220, which is elongated in the vertical direction, is formed in a side portion of the upper plate100or the lower plate200so as to be aligned with the position of the restraint pin470.

The restraint pin470is slidably inserted into and accommodated in the long hole120or220. Accordingly, the distance that the upper plate100or the lower plate200is capable of moving vertically may be limited. When the restraint pin470is located at the lowermost end of the long hole120in the upper plate100, the upper plate100has the maximum height, that is, the upper plate100is raised as far as possible.

FIG.8is a view showing the driving bolt according to the embodiment of the present invention,FIG.9is a view showing a fixing ring according to the embodiment of the present invention,FIG.10is a view showing the state in which the fixing ring is coupled to the driving bolt according to the embodiment of the present invention,FIG.11is a view showing a fixing cap according to the embodiment of the present invention,FIGS.12A-12Bare partial cross-sectional views showing the state in which the fixing cap according to the embodiment of the present invention is inserted into the block, andFIG.13is a partial cross-sectional view showing the state in which a fixing end of the fixing cap according to the embodiment of the present invention is in contact with and supported by a block end.

As shown in the drawings, the driving bolt500includes the bolt body510, the bolt head520, and a fixing groove530. The bolt body510is formed in a cylindrical shape, and has the male threads511formed on the outer circumferential surface thereof. The bolt head520is coupled to the rear end of the bolt body510, and has a diameter larger than that of the bolt body510. The fixing groove530is formed between the bolt body510and the bolt head520, and has a diameter smaller than that of the bolt body510.

As shown inFIGS.9and10, a fixing ring540is coupled to the fixing groove530. The fixing ring540is formed in a ‘C’ shape with one side thereof open, and may be inserted into and accommodated in the fixing groove530, or may be separated from the fixing groove530.

When the fixing ring540is coupled to the fixing groove530, the rear surface of the fixing ring540is in contact with the front surface of the block400. The bolt head520, having a diameter larger than that of the bolt body510, is accommodated in the block400, and the fixing ring540is in contact with the front surface of the block400. Accordingly, the driving bolt500is rotatably coupled to the block400to pull the block400.

As shown inFIGS.11and12A-12B, a fixing cap550to come into contact with the rear end of the bolt head520may be further accommodated in the block hole411in the block400so as to be rotatable therein.

FIG.12Ais a partial cross-sectional view showing the state in which the fixing cap according to the embodiment of the present invention is in contact with the rear end of the bolt head, andFIG.12Bis a partial cross-sectional view showing the state in which the fixing cap according to the embodiment of the present invention rotates to be in close contact with the rear end of the bolt head.

A bolt inclined surface521inclined at a predetermined inclination angle is formed at the rear end of the bolt head520. A fixing inclined surface551is formed at the front end of the fixing cap550to come into contact with the rear end of the bolt head520, the fixing inclined surface551being formed so as to correspond to the shape of the bolt inclined surface521.

When the vertical distance between the upper plate100and the lower plate200is set by operating the driving bolt500as shown inFIG.12A, the fixing inclined surface551presses the bolt inclined surface521by rotating the fixing cap550inserted into the block hole411, and the fixing inclined surface551and the bolt inclined surface521are kept in close contact with each other, as shown inFIG.12B. Accordingly, the driving bolt500is firmly fixed without loosening.

In this case, the fixing cap550includes a fixing hole552opening in the longitudinal direction (the forward-and-rearward direction) of the frame300, and a plurality of fixing rotation grooves553are recessed into a side portion of the fixing cap550so as to hold and rotate the fixing cap550. In the embodiment, the number of fixing rotation grooves553is four, but the number thereof is not limited thereto.

A fixing end554is formed to protrude in the shape of a ring from the side portion of the fixing cap550. As shown inFIG.13, the fixing end554is in contact with and supported by a block end412formed to protrude from the inside of the block hole411. Accordingly, the fixing cap550is prevented from becoming separated from the block hole411.

FIG.14is a view showing the frame according to the embodiment of the present invention,FIG.15is a partial cross-sectional view showing the state in which the driving bolt is inserted into a front part of the frame according to the embodiment of the present invention,FIG.16are views showing the state in which the vertical distance between the upper plate and the lower plate according to the embodiment of the present invention is increased,FIG.17is a view showing the state in which the vertical distance between the upper plate and the lower plate according to the embodiment of the present invention is increased, seen from the rear,FIG.18is a cross-sectional view showing the state in which the vertical distance between the upper plate and the lower plate according to the embodiment of the present invention is increased, andFIG.19is a cross-sectional view showing the state in which the vertical distance between the upper plate and the lower plate according to the embodiment of the present invention is decreased.

FIG.16Ais a view showing the state in which the vertical distance between the upper plate and the lower plate according to the embodiment of the present invention is increased, seen from above, andFIG.16Bis a view showing the state in which the vertical distance between the upper plate and the lower plate according to the embodiment of the present invention is increased, seen from below.

As shown in the drawings, the frame300includes the front part310, the connection part320, and the rear part330.

A front inclined surface312oriented at a predetermined angle relative to the center of the front part310is formed on the front surface of the front part310, and a rear inclined surface313oriented at a predetermined angle relative to the center thereof is also formed on the rear surface of the front part310.

As shown inFIG.15, the front hole311is formed in the center of the front part310in the longitudinal direction (the forward-and-rearward direction), and female threads311aare formed on the inner surface of the front hole311to be engaged with the male threads511of the driving bolt500.

When the driving bolt500is rotated, the male threads511of the driving bolt500are engaged with the female threads311aof the front hole311. Accordingly, the driving bolt500may move forwards or rearwards with respect to the frame300.

The connection part320extends rearwards from the rear end of the front part310. In the embodiment, a pair of connection parts320is provided, but the number thereof is not limited thereto. The internal space321is defined between the pair of connection parts320, and the block400and the driving bolt500may be accommodated in the internal space321.

A stopper322may be formed to protrude from one side of the connection part320, and the upper protrusion420or the lower protrusion430of the block400may be in contact with and supported by the stopper322.

The rear part330is coupled to the rear end of the connection part320. A frame penetration hole331is formed in the center of the rear part330in the longitudinal direction (the forward-and-rearward direction), and the frame penetration hole331is connected to the internal space32.

A mechanism-coupling groove332is formed to be recessed into a side portion of the rear part330. The mechanism-coupling groove332allows the frame300to be coupled to a predetermined mechanism. In the embodiment, each of the mechanism-coupling grooves332is formed in a corresponding one of opposite sides of the rear part330, but the present invention is not limited thereto.

As shown inFIGS.16A-16B, a first front inclined rail314is formed on the rear inclined surface313of the front part310that is in contact with the upper plate100, and a second front inclined rail315is formed on the rear inclined surface313of the front part310that is in contact with the lower plate200.

An upper inclined rail130is formed on the upper plate100so that the first front inclined rail314may be inserted into and accommodated in the upper plate100. A lower inclined rail230is formed on the lower plate200so that the second front inclined rail315may be inserted into and accommodated in the lower plate200.

When the driving bolt500is moved forwards by rotating the driving bolt500, the block400coupled to the driving bolt500also moves forwards. When the block400moves forwards, the upper plate100and the lower plate200also move forwards.

When the upper plate100and the lower plate200move forwards as shown inFIG.18, the upper inclined rail130moves forwards and upwards in the state of being accommodated in the first front inclined rail314, and the lower inclined rail230moves forwards and downwards in the state of being accommodated in the second front inclined rail315. Accordingly, the distance between the upper plate100and the lower plate200is increased, thereby making it possible to increase the vertical distance between the upper plate100and the lower plate200.

On the other hand, when the driving bolt500is moved rearwards by rotating the driving bolt500, the block400coupled to the driving bolt500also moves rearwards. When the block400moves rearwards, the upper plate100and the lower plate200also move rearwards.

When the upper plate100and the lower plate200move rearwards as shown inFIG.19, the upper inclined rail130moves rearwards and downwards in the state of being accommodated in the first front inclined rail314, and the lower inclined rail230moves rearwards and upwards in the state of being accommodated in the second front inclined rail315. Accordingly, the distance between the upper plate100and the lower plate200is decreased, thereby making it possible to decrease the vertical distance therebetween.

As shown inFIG.17, a first frame protrusion333protruding toward the upper plate100is formed on the upper portion of the rear part330, and a second frame protrusion335protruding toward the lower plate200is formed on the lower portion of the rear part330.

An upper accommodation groove140is formed in the upper plate100to allow the first frame protrusion333to be accommodated in the upper accommodation groove140, and a lower accommodation groove240is formed in the lower plate200to allow the second frame protrusion335to be accommodated in the lower accommodation groove240.

When the vertical distance between the upper plate100and the lower plate200is increased, the first frame protrusion333and the second frame protrusion335are separated from the upper accommodation groove140and the lower accommodation groove240, respectively. On the other hand, when the vertical distance between the upper plate100and the lower plate200is decreased, the first frame protrusion333and the second frame protrusion335are accommodated in the upper accommodation groove140and the lower accommodation groove240, respectively.

A first frame inclined surface334inclined at a predetermined inclination angle is formed on the rear surface of the first frame protrusion333, and a second frame inclined surface336inclined at a predetermined inclination angle is formed on the rear surface of the second frame protrusion335.

An upper inclined surface141is formed in the upper accommodation groove140of the upper plate100so as to correspond to the shape of the first frame inclined surface334. Accordingly, the upper inclined surface141may contact the first frame inclined surface334. Further, a lower inclined surface241is formed in the lower accommodation groove240of the lower plate200so as to correspond to the shape of the second frame inclined surface336. Accordingly, the lower inclined surface241may contact the second frame inclined surface336.

When the upper plate100and the lower plate200move forwards, the upper inclined surface141moves forwards and upwards while riding over the first frame inclined surface334, and the lower inclined surface241moves forwards and downwards while riding over the second frame inclined surface336. As a result, the distance between the upper plate100and the lower plate200is increased, thereby making it possible to increase the vertical distance between the upper plate100and the lower plate200.

On the other hand, when the upper plate100and the lower plate200move rearwards, the upper inclined surface141moves rearwards and downwards while riding down the first frame inclined surface334, and the lower inclined surface241moves rearwards and upwards while riding down the second frame inclined surface336. As a result, the distance between the upper plate100and the lower plate200is decreased, thereby making it possible to decrease the vertical distance therebetween.

FIG.20are views showing the overall appearance of a height-expandable spinal cage according to another embodiment of the present invention, andFIGS.21A-21Bare views showing the overall appearance of a height-expandable spinal cage according to still another embodiment of the present invention.

FIG.20Ais a view showing the state before the height of the height-expandable spinal cage according to another embodiment of the present invention is increased, andFIG.20Bis a view showing the state after the height of the height-expandable spinal cage according to another embodiment of the present invention is increased.FIG.21Ais a view showing the state before the height of the height-expandable spinal cage according to still another embodiment of the present invention is increased, andFIG.21Bis a view showing the state after the height of the height-expandable spinal cage according to still another embodiment of the present invention is increased.

As shown inFIGS.20A-20B, the height-expandable spinal cage according to another embodiment of the present invention includes the upper plate100, the lower plate200, the frame300, the block400, and the driving bolt500, as in the case of the height-expandable spinal cage according to the embodiment of the present invention shown inFIGS.1A-1B.

In the height-expandable spinal cage according to another embodiment of the present invention, both the upper portion of the upper accommodation groove140and the lower portion of the lower accommodation groove240are open, and as such, the upper end of the first frame protrusion333and the lower end of the second frame protrusion335are exposed to the outside. On the other hand, the height-expandable spinal cage according to the embodiment of the present invention shown inFIGS.1A-1Bis different in that the lower portion of the lower accommodation groove240is closed, and as such, the lower end of the second frame protrusion335is not exposed to the outside.

As shown inFIGS.21A-21B, the height-expandable spinal cage according to still another embodiment of the present invention also includes the upper plate100, the lower plate200, the frame300, the block400, and the driving bolt500, as in the case of the height-expandable spinal cage according to the embodiment of the present invention shown inFIG.1.

In the height-expandable spinal cage according to still another embodiment of the present invention, both the upper portion of the upper accommodation groove140and the lower portion of the lower accommodation groove240are also open, and as such, the upper end of the first frame protrusion333and the lower end of the second frame protrusion335are exposed to the outside, as in the case of the height-expandable spinal cage according to another embodiment of the present invention shown inFIGS.20A-20B.

Meanwhile, the first frame protrusion333of the height-expandable spinal cage according to still another embodiment of the present invention is further connected to the mechanism-coupling groove332through an additional connection member340. On the other hand, the height-expandable spinal cage according to the embodiment of the present invention shown inFIGS.1A-1Bis different in that there is no additional connection member between the first frame protrusion333and the mechanism-coupling groove332other than the rear part330.

As is apparent from the above description, a height-expandable spinal cage of the present invention having the above-described configuration has an effect of making it possible to increase or decrease the vertical distance between an upper plate and a lower plate by moving a block forwards or rearwards in the longitudinal direction inside a frame.

In other words, according to the present invention, the height-expandable spinal cage may be implanted into an affected area of a patient suffering from a spinal injury in the state in which the height is reduced to the minimum height thereof, and the height of the height-expandable spinal cage may be expanded in the affected area, thereby having an effect of being usefully used for minimally invasive surgery.

Although preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.