JP2008284300A - Cement injector for reconstruction of vertebral body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inject bone cement in such a way that bone cement injected from the side of a pedicle of arch of vertebra is hard to leak from a crack or the like existing in a side wall of the vertebral body out of the vertebral body. <P>SOLUTION: The cement injector 1 for reconstruction of the vertebral body is provided with an insert tube 4 to be inserted into the vertebral body through an introducing hole formed in the pedicle of arch of vertebra, and a cement feed part 2 to feed fluid bone cement into the vertebral body through the inert tube 4. The tip of the insert tube 4 is closed, while more than one delivery ports 6 are provided at a tip part of the insert tube 4 in the radial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cement injection tool for vertebral body reconstruction.

Conventionally, as a bone cement injection tool for vertebral body reconstruction, one that injects fluid bone cement from the tip of an insertion tube inserted through an introduction hole formed in a pedicle is known ( For example, see Patent Document 1.)
In order to inject bone cement with this injection tool, a balloon attached to the distal end of the insertion tube is inflated in the vertebral body to secure a bone cement injection space, and then the balloon is removed and the bone cement is placed in the secured injection space. There are a method for injecting bone and a method for inflating by injecting bone cement into the balloon.

JP 2006-263184 A

  However, since the collapsed vertebral body has cracks and breakage on the side wall opposite to the pedicle, in the method of removing the balloon and injecting bone cement, the bone cement injected from the pedicle side is There is an inconvenience that it is easy to leak out of the vertebral body from a crack or the like existing in front of the injection direction. In addition, the method of inflating the bone cement by injecting it into the balloon has few such inconveniences, but it is difficult to realize a balloon that can inject the bone cement to the end without breaking it. If it is broken, the same inconvenience occurs as when the balloon is removed.

  The present invention has been made in view of the above-described circumstances, and the bone cement injected from the pedicle side is not easily leaked out of the vertebral body from a crack or the like existing on the side wall of the vertebral body. It aims at providing the cement injection tool for vertebral body reconstruction which can inject | pour cement.

In order to achieve the above object, the present invention provides the following means.
The present invention includes an insertion tube that is inserted into the vertebral body through an introduction hole formed in the pedicle, and a cement supply unit that supplies fluid bone cement to the vertebral body through the insertion tube. And a vertebral body reconstruction cement injection tool in which the distal end of the insertion tube is closed and at least one discharge port that opens in the radial direction is provided at the distal end of the insertion tube.

  According to the present invention, the bone cement is inserted into the insertion tube by operating the cement supply unit in a state where the insertion tube is inserted into the introduction hole formed in the pedicle and the distal end thereof is disposed in the space in the vertebral body. It is supplied to the vertebral body via Since the distal end of the insertion tube is closed, the supplied bone cement is not discharged in the longitudinal direction from the distal end in the longitudinal direction of the insertion tube. Therefore, it is possible to prevent the bone cement from being discharged directly toward the crack of the vertebral body existing in the longitudinal direction of the insertion tube, and to suppress leakage of the bone cement to the outside of the vertebral body through the crack. be able to.

  In addition, since one or more discharge ports are opened in the radial direction at the distal end portion of the insertion tube, the bone cement supplied through the insertion tube passes through these discharge ports in the radial direction of the insertion tube. Discharged. Since the end plate of the collapsed vertebral body is close in the radial direction of the insertion tube, it is possible to apply pressure in the direction of widening the interval between the end plates by discharging bone cement in the radial direction of the insertion tube. , Vertebral body reconstruction can be facilitated.

In the above invention, the distal end of the insertion tube may be closed with a cap made of an elastic material, and the discharge port may be provided in the cap.
By doing so, the cap made of an elastic material is expanded by the pressure of the bone cement supplied in the insertion tube, and pushes away the cancellous bone and the like existing in the vertebral body to make a space for filling the bone cement. Form. Further, when the cap made of an elastic material is expanded by the pressure of the bone cement, the discharge port provided in the cap is enlarged, and the discharge of the bone cement can be facilitated. Accordingly, the vertebral body can be reduced by pressing the end plate of the vertebral body in a direction in which the endplate of the vertebral body is expanded by the bone cement discharged radially outward from the cap.

Moreover, in the said invention, the said discharge outlet is good also as consisting of the slit formed in the surrounding wall of the said cap along the axial direction.
By doing in this way, when a cap deform | transforms with the pressure of bone cement, the discharge outlet consisting of a slit opens and a large amount of bone cement can be discharged radially outward of the cap.

Moreover, in the said invention, it is good also as a plurality of the said discharge outlets being provided in the circumferential direction at intervals.
In this way, the cap can be easily deformed, the discharge port can be opened widely, and a large amount of bone cement can be discharged radially outward.

In the above invention, the discharge port may be opened and closed by a cantilevered valve body having a swing end on the insertion tube side.
By doing so, when the bone cement supplied from the cement supply section through the insertion tube is discharged from the discharge port of the cap, the rocking end of the valve body is displaced by the pressure of the bone cement. The discharge port can be greatly opened. Since the swinging end of the valve body is located on the insertion tube side, the bone cement that is about to be discharged to the tip end side of the cap is blocked and the discharge of bone cement in the direction in which cracks etc. exist is avoided. Therefore, leakage outside the vertebral body can be prevented more reliably.

  According to the present invention, there is an effect that the bone cement injected from the pedicle side can be injected by a method in which it is difficult to leak out from the vertebral body due to a crack or the like existing on the side wall of the vertebral body. .

A cement injection tool 1 for vertebral body reconstruction according to an embodiment of the present invention will be described below with reference to FIGS. 1 and 2.
As shown in FIG. 1, the vertebral body reconstruction cement injection tool 1 according to the present embodiment can accommodate and discharge fluid bone cement such as acrylic cement (PMMA) or calcium phosphate cement (CPC). A syringe-shaped cement supply unit 2, an elongated insertion tube 4 connected to the discharge port 3 of the cement supply unit 2, and a cap 5 attached to the distal end of the insertion tube 4 are provided.

The cement supply unit 2 can push out the bone cement contained therein from the discharge port 3 by pushing the piston 2b into the cylinder 2a.
The insertion tube 4 is an elongated straight tubular member having an outer diameter smaller than the diameter of the introduction hole formed through the pedicle, and one end of the insertion tube 4 is connected to the discharge port 3 of the cement supply unit 2. It is connected.

The cap 5 is a cylindrical member made of, for example, silicone rubber and closed at one end, and is attached to the other end of the insertion tube 4 to close the opening.
In addition, the cap 5 is provided with a plurality of, for example, four, outlets 6 formed of slits formed along the longitudinal direction at intervals in the circumferential direction on the peripheral wall.

The operation of the cement injection tool 1 for vertebral body reconstruction according to the present embodiment configured as described above will be described below.
In order to reconstruct a collapsed vertebral body using the cement injection tool 1 for vertebral body reconstruction according to the present embodiment, first, an introduction hole is formed through the pedicle by a known method, The cancellous bone and the like present in the medullary cavity are removed while preserving the rear wall.

  Next, the insertion tube 4 of the cement injection tool 1 for vertebral body reconstruction according to the present embodiment is inserted into the vertebral body through the introduction hole. Thereby, the cap 5 attached to the tip of the insertion tube 4 is disposed in the medullary cavity.

  In this state, by pushing the piston 2b into the cylinder 2a, the bone cement accommodated in the cement supply unit 2 is discharged. The bone cement discharged from the discharge port 3 of the cement supply unit 2 is guided through the insertion tube 4 connected to the discharge port 3 toward the medullary cavity. When reaching the cap 5 at the distal end of the insertion tube 4, the bone cement is blocked by the cap 5, and further movement along the longitudinal direction of the insertion tube 4 is restricted.

  Since the cap 5 is made of an elastic material such as silicone rubber, when the pressure of the blocked bone cement A is increased, the cap 5 is elastically deformed and radially outward as shown in FIG. The discharge port 6 made of a slit is expanded. Since the discharge ports 6 are provided in the peripheral wall at intervals in the circumferential direction, the bone cement A is discharged radially outward as indicated by an arrow B in FIG.

  In the direction further forward from the tip of the cap 5 indicated by the arrow C in FIG. 2, a region where many cracks and the like exist in the vertebral body is arranged. According to the cement injection tool for vertebral body reconstruction according to the present embodiment, since the bone cement A discharged from the distal end of the insertion tube 4 in the direction of the arrow C is blocked by the cap 5, there are many cracks and the like. Direct ejection toward the region is prevented. As a result, it is possible to prevent a disadvantage that the bone cement A discharged vigorously leaks out of the vertebral body due to a crack in the vertebral body or the like.

  In addition, in the direction indicated by arrow B in FIG. 2, there are upper and lower endplates that are close to each other due to the collapse of the vertebral body. By discharging bone cement A in that direction, The end plate can be pressed from the medullary cavity of the vertebral body by the pressurized bone cement A to reduce the plate. In this case, the cap 5 is made of an elastically deformable material, whereby the cap 5 is elastically deformed by the pressure of the bone cement A to widen the discharge port, and the bone cement A can be smoothly discharged with a small flow resistance. it can.

In the present embodiment, the case of having the linear slit-like discharge port 6 is described as an example, but instead of this, as shown in FIG. The discharge port 6 having the cantilever-like valve body 8 having the swing end 8a on the insertion tube 4 side may be constituted by the U-shaped cut 7.
In this case, it is preferable to employ a cap 5 made of a material that is elastically deformed at the base end side of the valve body 8 and that is not elastically deformed at other portions.

  By doing in this way, when the pressure of the bone cement A in the cap 5 increases, the valve body 8 is elastically deformed and the discharge port 6 is opened as shown in FIG. Is discharged outward in the radial direction of the cap 5. In this case, the valve body 8 opens the discharge port 6 by swinging the swing end 8 a on the insertion tube 4 side, so that the discharge port 6 is opened from the rear end side of the cap 5.

  Accordingly, since the bone cement A once blocked by the cap 5 is discharged from the opened discharge port 6, the bone cement A is discharged toward the obliquely rearward in the radial direction as indicated by the arrow B ′. Is done. Thereby, the discharge of the bone cement A in the direction of the arrow C, that is, the direction where there is a region where there are many cracks or the like is further effectively suppressed, and the leakage of the bone cement A outside the vertebral body is prevented. Can do.

  Also, with this configuration, the discharge port 6 is opened by the pressure of the bone cement A, so that the flow resistance when the bone cement A is discharged is reduced and the discharge can be smoothly performed. is there.

In the present embodiment, the cap 5 is made of an elastic material such as silicone rubber. Silicone rubber is preferable because it has biocompatibility. However, the present invention is not limited to this, and it goes without saying that other resin materials having biocompatibility and elasticity may be employed.
Moreover, you may employ | adopt what is equipped with the cap 5 which has the discharge outlet 6 which does not change a magnitude | size without elastically deforming. Moreover, the cap 5 and the insertion tube 4 may be comprised integrally.
In addition, although four discharge ports 6 are provided at intervals in the circumferential direction, the present invention is not limited to this, and another arbitrary number of discharge ports 6 may be provided.

It is a perspective view which shows the cement injection tool for vertebral body reconstruction which concerns on one Embodiment of this invention. It is a partial perspective view which shows the mode of discharge of the bone cement from the front-end | tip of the cement injection tool for vertebral body reconstruction of FIG. It is a partial perspective view which shows the modification of the cement injection tool for vertebral body reconstruction of FIG. 1, (a) The state in which the discharge outlet was closed, (b) The figure which showed the state in which the discharge outlet was opened, respectively. .

Explanation of symbols

A Bone cement 1 Cement injection tool for vertebral body reconstruction 2 Cement supply part 4 Insertion tube 5 Cap 6 Discharge port 8 Valve body 8a Swing end

Claims (5)

An insertion tube that is inserted into the vertebral body through an introduction hole formed in the pedicle;
A cement supply unit for supplying fluid bone cement into the vertebral body through the insertion tube,
A cement injection tool for vertebral body reconstruction, wherein the distal end of the insertion tube is closed and at least one discharge port opening in the radial direction is provided at the distal end portion of the insertion tube.   The cement injection tool for vertebral body reconstruction according to claim 1, wherein the distal end of the insertion tube is closed by a cap made of an elastic material, and the discharge port is provided in the cap.   The cement injection tool for vertebral body reconstruction according to claim 2, wherein the discharge port includes a slit formed in an axial direction on a peripheral wall of the cap.   The cement injection tool for vertebral body reconstruction according to claim 3, wherein a plurality of the discharge ports are provided at intervals in the circumferential direction.   The cement injection tool for vertebral body reconstruction according to any one of claims 2 to 4, wherein the discharge port is opened and closed by a cantilevered valve body having a swing end on the insertion tube side.

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