JP4581097B2 - Interspinous process spacer, extraction screwdriver, internal screw for fixation, surgical kit and method of extracting interspinous process spacer - Google Patents

Description

  The present invention relates to a minimally invasive implant for the purpose of enlargement between spinous processes, and in particular, interspinous process spacer for expanding the spinal canal, removal driver, internal screw for fixation, surgical kit, and interspinous process spacer. It is related to the method of removing.

  The spinal canal is a longitudinal cylindrical space in the center of the spine (vertebra), in which the spinal cord and the tail (nerve) are contained and firmly protected. Spinal canal stenosis, where the spinal canal is narrowed due to various causes such as deformation of bones, cartilage, ligaments, etc., and the nerve inside is compressed, the number of patients increases with the aging society, It is a big social problem.

  Lumbar spinal canal stenosis, in particular, causes deformation and thickening of the lumbar vertebrae and facet joints, as well as degeneration and swelling of the soft disc, and thickening of the ligaments, which narrows the spinal canal and narrows the nerves and blood vessels. A state of pressing or tightening. Symptoms are typically gait disturbances such as nervous intermittent claudication, and these symptoms are characterized by the fact that the lower limbs do not appear forward after walking for a few minutes, and if you take a break and rest, you can walk again. . In addition, lower limb symptoms such as sciatica, numbness of the lower limbs, coldness and weakness, low back pain, bladder rectal disorder (disturbation of urination and defecation) are lumbar spinal canal stenosis.

  The present inventor has developed an interspinous process spacer as a minimally invasive implant for the purpose of dilating between the spinous processes in order to cope with lumbar spinal canal symptoms caused by such lumbar spinal canal stenosis (Patent Document 1). In such an interspinous process spacer, a substantially conical screw part screwed between the spinous processes, a spacer part formed in the longitudinal direction of the screw part, an appropriate tool can be engaged, or an appropriate connecting member can be attached. And a through-hole is formed in the axial center of the screw portion, the spacer portion, and the head, and the outer contour of the overall shape has an elliptical shape (see Patent Document 1).

A method for percutaneously expanding the interspinous process using this interspinous process spacer will be described.
First, the position where the spinal canal is constricted is confirmed by a fluoroscopic technique such as X-ray, and then the guide member is introduced from the posterior outer side through the skin of the patient's back to the position. Thereafter, the guide member is inserted into the through hole of the interspinous process spacer, and the screw portion of the interspinous process spacer is rotated and inserted using a tool such as a screwdriver. By rotating and inserting the screw part, the space between the spinous processes is enlarged, then the screw part is passed through, the spacer part is sandwiched between the spinous processes to fix the space between the spinous processes, and finally the guide member and the tool are removed.

  Also, in other interspinous process spacers, in order to insert the spacer between the spinous processes, a guide pin is first inserted from the skin incision site, and then an obturator covering it is inserted, This obturator is used to expand the spinous processes and finally insert a spacer (see Patent Document 2).

PCT / JP2006 / 315382 WO 2005/073021 International Publication

However, once the interspinous process spacer described above is fitted between the spinous processes, it is not easy to remove it from the body. That is, in order to take out the interspinous process spacer from the body, a skin incision of a certain size is required, which causes a surgical invasion to the patient.
An object of the present invention is to provide a device and a method capable of taking out the interspinous process spacer from the body to the outside for the purpose of realizing a minimally invasive treatment method for spinal stenosis.

The present inventor has invented the interspinous process spacer according to the present invention and the method for removing the spinal process spacer through many clinical experiences for spinal canal stenosis.
In order to achieve the above object, the interspinous process spacer of the present invention is a device for maintaining a predetermined distance between adjacent spinous processes, and has a generally conical screw part screwed between the spinous processes, It has a spacer part formed in the longitudinal direction of the screw part and a head part that can be appropriately engaged with a tool or can be appropriately attached with a connecting member, and a through-hole is formed in the axial center of the screw part, the spacer part, and the head part. In the interspinous process spacer,
A first recess into which the extraction driver can be fitted to the rear end of the head;
A structure in which a second recess is formed in the bottom of the first recess, which is smaller than the diameter of the first recess, and is provided with a thread that can be screwed into the fixing internal screw. It is.

  The interspinous process spacer of the present invention uses the opening force generated when the screw part is inserted while being screwed between the spinous processes, so that the space between the spinous processes is easily expanded, and the screw part passes between the spinous processes. In this way, the spacer portion is sandwiched between the adjacent spinous processes to expand and fix (maintain a predetermined interval). The head that can be appropriately engaged with the tool or can be appropriately connected with the connecting member is, for example, having a hole for a hexagonal screwdriver tool. Using a driver tool, the interspinous process spacer of the present invention can be pushed in from the small incision site toward the internal spinous process while rotating. In addition, since the through hole is formed in the axial center of the screw part and the spacer part, it is possible to connect with a guide member such as a guide wire through the through hole. By the guide member, the interspinous process spacer can be guided between the spinous processes from the small incision site toward the internal spinous processes.

In such an interspinous process spacer, a first recessed portion into which a removal driver can be fitted to the rear end portion of the head and a bottom portion of the first recessed portion are smaller than the diameter of the first recessed portion, and are used for fixing. By forming the second concave portion provided with a thread that can be screwed with the inner screw, the interspinous process spacer can be taken out from the body by a minimally invasive procedure.
Here, the extraction driver is a device that fits with the head of the interspinous process spacer and rotates the screw part of the interspinous process spacer in the direction of taking out the interspinous process spacer from the body to the outside.
The fixing internal screw is screwed with the head portion of the interspinous process spacer to be integrated with each other, and functions as a pulling rod of the interspinous process spacer.
Here, in the head of the interspinous process spacer, a second recess is provided at the bottom of the first recess that can be fitted with the extraction driver, and the second recess is smaller than the first recess diameter. Threads that can be screwed onto the fixing internal screw are provided by inserting the fixing internal screw through the hole passing through the inside of the removal driver in the longitudinal direction as a guide. This is for screwing the head of the spacer between the protrusions.

  Here, in the shape of the first recess of the interspinous process spacer described above, it is preferable that the opening is wider than the bottom and is a polygonal, reverse-tapered truncated pyramid or elliptical truncated cone. By making the opening portion wider than the bottom portion, it is easy to insert an extraction driver into the head, and the burden on the operator is reduced. In addition, by using a reverse-tapered truncated pyramid or elliptical truncated cone, it is possible to rotate the screw portion of the interspinous process spacer using the extraction screwdriver. The shape of the 1st recessed part which the extraction driver can fit in the rear-end part of the head of the interspinous process spacer is shown more concretely.

  In addition, the interspinous process spacer is preferably formed so that the first recess, the second recess, and the axis of the through hole are coaxial. This is because the insertion center of the removal driver, the fixing internal screw, and the guide wire into the body can be made uniform because the first concave portion, the second concave portion, and the axis of the through hole are coaxial.

Further, the interspinous process spacer has an oval outer contour of the overall shape, a boundary portion between the screw portion and the spacer portion, and a boundary portion between the spacer portion and the head portion are formed in a tapered shape, and the screw of the screw portion More preferably, the crest is formed over the boundary portion between the screw portion and the spacer portion.
The reason why the outer contour of the overall shape of the interspinous spacer is made elliptical is that, based on the accumulation of clinical experience, it has been found that the interspinous spacer is generally easier to fit between the vertebral arches if it is elliptical as a whole. .
In addition, the boundary part between the screw part and the spacer part and the boundary part between the spacer part and the head are formed in a taper shape, and the thread of the screw part is formed over the boundary part between the screw part and the spacer part. This is to make it easier for the spacer portion sandwiched between the spinous processes to come out from between the spinous processes when the spacer is rotated backward to retract the interspinous spacer to be removed from the body.

The extraction driver of the present invention is an instrument used to remove the interspinous process spacer from between the spinous processes, and is composed of a main body part having a long structure and a grip part, and a distal end part of the main body part A convex portion that can be fitted to the first concave portion of the interspinous process spacer is formed, and a through hole is formed in the axial center from the gripping portion to the distal end portion of the main body portion.
Here, specifically, the shape of the tip portion of the extraction driver is preferably a tapered pyramid or an elliptic frustum having a polygonal cross section. The screw driver of the interspinous process spacer can be rotated by the extraction driver. The shape of the tip of the extraction driver is, for example, a hexagonal screwdriver.

An internal screw for fixation according to the present invention is an instrument used to remove the interspinous process spacer from the interspinous process, and is composed of a main body part having a long structure and a grip part, and the distal end of the main body part A thread that can be screwed into the second recess of the interspinous process spacer.
Here, when a stopper portion is further provided between the main body portion of the fixing inner screw and the grip portion, and the fixing inner screw is inserted until the stopper portion comes into contact with the through hole of the above-described removal driver. The stopper is preferably formed so that the tip of the fixing internal screw protrudes from the tip of the removal driver. By providing such a stopper portion, it becomes easier to grasp the timing of turning the fixing inner screw after the fixing inner screw is inserted into the through hole of the removal driver, and excessive insertion of the screw can be avoided. It becomes possible.

Further, the removal kit of the present invention is composed of the extraction driver and the fixing internal screw. The surgical kit of the present invention includes the interspinous process spacer, the removal driver, and the fixing internal screw.

The method for removing the interspinous spacer of the present invention includes the following steps (1) to (5).
(1) A step of lifting the head portion of the interspinous process spacer fitted between the spinous processes with a guide member to change the axial direction of the interspinous process spacer. Step (3) Inserting the fixing internal screw into the through hole of the extraction driver (4) Supporting the gripping part of the extraction driver and inserting the fixing internal screw Rotating and completely screwing the tip of the fixing internal screw into the second recess of the head of the interspinous process spacer (5) Simultaneously reverse rotating both the fixing internal screw and the removal screwdriver Reversing and reversing the screw part of the interspinous process spacer

According to the internal screw for fixation , the extraction screwdriver , the extraction kit , the operation kit, and the interspinous process spacer extraction method according to the present invention, the interspinous process spacer is removed from the body with a minimally invasive procedure. It has the effect that it can take out from the outside.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1A shows a configuration diagram of a configuration diagram of the interspinous process spacer of the present invention. The interspinous process spacer 1 of the present invention includes a substantially conical screw part 2 (range A in FIG. 1) screwed between the spinous processes, and a spacer part 3 (FIG. 1) formed in the longitudinal direction of the screw part. B) and a head 4 (range C in FIG. 1) that can be appropriately engaged with a tool or that can be appropriately connected with a connecting member, and has an axial center of the screw portion 2, the spacer portion 3, and the head 4. A through hole 5 is formed in the bottom.

FIG. 1B is a front view of the rear end of the head of the interspinous process spacer 1.
As shown in FIGS. 1 (a) and 1 (b), a first recess 6 into which an extraction driver (not shown) can be fitted at the rear end of the head 4 of the interspinous process spacer 1 is shown. And a second recess 7 provided with a screw thread on the bottom of the first recess, which is smaller than the diameter of the first recess, and can be screwed into an internal fixing screw (not shown). Is formed. The second recess 7 has a thread cut so as to be a reverse screw for screwing with the fixing internal screw.
The size of the first concave portion 6 and the second concave portion 7 provided in the rear end portion of the head 4 of the interspinous process spacer 1 and the through hole 5 provided in the axial center of the interspinous process spacer 1. The relationship is shown in FIG.
Moreover, in the shape of the 1st recessed part 6 of the spacer between spinous processes, the opening part is large compared with the bottom part, and the cross section is a hexagonal truncated cone of a reverse taper shape with a polygon. As will be described later, the shape of the tip of the driver for removing the interspinous process spacer 1 is a hexagonal screwdriver.

  Next, FIG. 3 shows a configuration diagram of the extraction screwdriver and the fixing internal screw. As shown in FIG. 3 (a), the extraction driver 20 of the present invention is an instrument used to remove the interspinous process spacer 1 from between the spinous processes, and has a main body 22 having a long structure. And a convex portion that can be fitted into the first concave portion 6 of the interspinous process spacer 1 is formed on the distal end portion 21 of the main body portion 22, and the shaft extends from the grasping portion 23 to the distal end portion 21 of the main body portion 22. A through hole 24 is formed in the center. The through hole 24 is a hole for allowing a fixing internal screw to be described later to pass therethrough. The shape of the tip portion of the extraction driver 20 is a tapered hexagonal frustum having a polygonal cross section. The screw driver 2 of the interspinous process spacer 1 can be rotated by the removal driver 20.

Next, the fixing internal screw of the present invention will be described. As shown in FIG. 3 (b), the internal fixing screw 30 of the present invention is an instrument used to remove the interspinous process spacer 1 described above from between the spinous processes, and has a long body structure. 32 and a gripping portion 33, and a thread 35 that can be screwed into the second recess 7 of the interspinous spacer 1 is formed at the tip of the main body.
Further, a stopper portion 34 is provided between the main body portion 32 and the grip portion 33 of the fixing internal screw 30. Thereby, when the fixing internal screw 30 is inserted until the stopper portion 34 comes into contact with the through hole 24 of the extraction driver 20 described above, the distal end portion of the fixing internal screw 30 becomes the distal end portion of the extraction driver 20. It protrudes from 21. As described above, by providing this stopper portion 34, it becomes easier to grasp the timing of turning the fixing inner screw 30 after inserting the fixing inner screw 30 into the through hole 24 of the removal driver 20, and Excessive insertion can be avoided.

Next, the method for removing the interspinous process spacer of the present invention will be described with reference to FIGS.
First, FIG. 4A shows an image diagram in which the interspinous process spacer is fitted between the spinous processes. Next, in FIG. 4-2, the head of the spacer fitted between the spinous processes is lifted with a guide wire (a bonbori type screwdriver may be used), and the axial direction (longitudinal direction) of the interspinous process spacer The state of changing the direction of is shown. Then, as shown in FIG. 4-3, the extraction driver 0 is inserted into the hole in the head of the interspinous process spacer 1. Then, as shown in FIG. 4-4, the fixing internal screw 30 is inserted into the through hole 24 of the removal driver 20. At this time, the fixing internal screw 30 is rotated while supporting the gripping portion 23 of the extraction driver 20, and the thread of the distal end portion of the internal fixing screw 30 is inserted into the second recess 7 of the head 4 of the interspinous process spacer 1. 35 is completely screwed.

  And as shown to FIGS. 4-5, it has the T-shaped holding part 23 of the driver 20 for extraction, and the holding part 33 of the internal screw 20 for fixation, and both reversely rotate simultaneously. As a result, as shown in FIG. 4-6, the interspinous process spacer 1 moves backward while rotating backward, and comes out between the spinous processes and the body.

  As described above, according to the surgical kit provided with the interspinous process spacer, the extraction driver and the fixing internal screw, and the method of removing the interspinous process spacer using the same, it is minimally invasive to the patient. The procedure allows the interspinous spacer to be removed from the body.

  INDUSTRIAL APPLICABILITY The interspinous process spacer, extraction driver, internal screw for fixation, surgical kit, and extraction method of the interspinous process spacer according to the present invention are used as medical instruments useful for minimally invasive surgical treatment for spinal stenosis Can be expected.

Configuration diagram of interspinous spacer View from the front of the fitting hole, screw hole, and through hole in the head of the interspinous process spacer. Configuration diagram of screwdriver for removal and internal screw for fixing Image of interspinous process spacer inserted between spinous processes The figure which shows a mode that the head of the spacer inserted between the spinous processes is lifted with a wire or a bonbon type screwdriver, and the direction of the axial direction (longitudinal direction) of the interspinous process spacer is changed. The figure which shows a mode that the screwdriver for extraction is inserted in the hole of the spacer head part between spinous processes The figure which shows a mode that the internal screw for fixation is inserted in the through-hole of the driver for extraction The figure which shows a mode that hold | grips the T-shaped holding part and fixing internal screw of a driver for extraction, and both reversely rotate simultaneously Figure showing how the interspinous spacer moves backward while rotating backward, and then exits between the spinous processes and the body.

Explanation of symbols

1 Interspinous process spacer
2 Screw part 3 Spacer part 4 Head
5 Through hole (insertion hole for guide wire)
6 1st recessed part 7 2nd recessed part 10 Spinous process 11 Vertebral body (lumbar vertebrae)
DESCRIPTION OF SYMBOLS 12 Vertebral hole 20 Removal driver 21 Tip part 22 Main body part 23 Gripping part 24 Through-hole 30 Fixing screw 31 Tip part 32 Main part 33 Gripping part 34 Stopper part 35 Screw thread 40 Guide wire

Claims (4)

A substantially conical screw part screwed between the spinous processes, a spacer part formed in the longitudinal direction of the screw part, and a head, and a through-hole is formed in the shaft center of the screw part, the spacer part, and the head The head is formed with a first recess into which a removal screwdriver can be fitted at the rear end, and the bottom of the first recess is smaller than the diameter of the first recess, and is threaded. An instrument used to remove the interspinous process spacer formed with a second recess provided with
A driver main body portion having a long structure and a driver gripping portion are formed, and a convex portion that can be fitted with the first concave portion of the interspinous process spacer is formed at the distal end portion of the driver main body portion. Used along with the driver for removal in which a through hole is formed in the axial center over the tip of the driver body,
A screw main body portion having a long structure and a screw gripping portion are formed, and a thread of a male screw that can be screwed with the female screw of the second recess of the interspinous process spacer is formed at the tip of the screw main body portion. When a stopper portion is provided between the screw main body portion and the screw gripping portion and inserted until the stopper portion comes into contact with the through hole of the removal driver, the screw tip portion is the tip portion of the removal driver. An internal screw for fixing, wherein the stopper portion is formed so as to protrude from the inside.
An internal screw for fixing according to claim 1;
A driver main body portion having a long structure and a driver gripping portion are formed, and a convex portion that can be fitted with the first concave portion of the interspinous process spacer is formed at the distal end portion of the driver main body portion. A driver for removal with a through hole formed in the shaft center over the tip of the driver body,
A removal kit for the interspinous process spacer.   In the shape of the first recess of the interspinous spacer, the opening is wider than the bottom, and the cross section is a polygonal reverse-tapered truncated pyramid or elliptical frustum, and the tip of the removal driver The kit for removing an interspinous process spacer according to claim 2, wherein the shape is a tapered pyramid or an elliptical frustum having a polygonal cross section. 1) An internal screw for fixing the interspinous process spacer according to claim 1;
2) A substantially conical screw portion that is screwed between the spinous processes, a spacer portion formed in the longitudinal direction of the screw portion, and a head, and penetrates through the screw portion, the spacer portion, and the axis of the head. A hole is formed, and the head has a first recess into which a removal screwdriver can be fitted at the rear end, and the bottom of the first recess is smaller than the diameter of the first recess, An interspinous process spacer formed with a second recess that can be screwed into the distal end of the fixing internal screw;
3) A driver main body portion having a long structure and a driver gripping portion, and a convex portion that can be fitted to the first concave portion of the interspinous process spacer is formed at the tip of the driver main body portion, and the driver gripping portion. An extraction driver having a through-hole formed in the axial center from the tip of the driver main body to the tip,
A surgical kit for interspinous process spacers.