JP5799066B2 - Spine fixation device and spinal fixation system - Google Patents

Description

  The present invention relates to a spinal fixation device and a spinal fixation system for fixing a spine.

  Conventionally, for fixing, correcting and stabilizing vertebrae such as cervical vertebra and lumbar vertebra, as a surgical operation, the rod is attached and fixed to a spinal fixation device fixed to the vertebra, and the rod is arranged along the spine. There is a known technique to do this.

  This spinal fixation device, for example, is formed integrally with a holder portion that holds the rod and a bone screw that is embedded in the vertebra so that it can be used properly according to the state of the spinal disease of the patient, the surgical content, etc. A fixed type device in which the holder part and the bone screw are relatively unrotatable, or a rotation type in which the holder part and the bone screw are formed separately and the holder part and the bone screw are relatively rotatable There is a device.

As a rotation type spinal fixation device, a pressure element is arranged in a holder portion that holds a bone screw head and a rod, and the pressure element presses the bone screw head so that the head does not turn. The thing of the structure hold | maintained is known (for example, refer patent document 1). However, since the head of the bone screw is temporarily tightened in the holder, for example, during surgery to correct spinal deformity such as kyphosis, a large load is applied to the holder and bone screw. If this is applied, the relative angle between the bone screw and the holder may change.
Therefore, a ring for maintaining the pressure of the head of the bone screw by the pressure element is arranged in the holder part, and the relative angle between the bone screw and the holder part is fixed, so that it is substantially equivalent to a fixed type device. A spinal fixation device having the above functions has also been proposed.

JP 2011-206538 A

  However, the ring for maintaining the pressure of the head of the bone screw by the pressure element is provided separately from the fixing screw for fixing the rod. For this reason, not only does the number of parts of the spinal fixation device increase and the configuration of the device becomes complicated, but also the device itself becomes large. Furthermore, a dedicated jig for fastening the ring and the fixing screw is also required. As a result, the handling property of the apparatus is deteriorated and the cost is increased.

  This invention is made | formed in view of such a problem, and the subject of this invention is the spinal fixation which can fix appropriately the relative angle of a bone screw and a holding | maintenance part with a simpler structure. An apparatus and spinal fixation system are provided.

In order to solve the above problem, the spinal fixation device of the invention according to claim 1 comprises:
A spinal fixation device connected to a rod to fix the spine,
A long implant member partially embedded in the vertebrae constituting the spine;
A holding portion capable of holding the embedded member and the rod,
The holding part is
An inner member comprising a non-implanted portion placement portion in which a non-implant portion that is not embedded in the vertebra of the implant member is disposed;
An outer member provided on the outer side of the inner member, and having an inner surface portion that can come into contact with substantially the entire outer surface portion of the non-embedded portion arrangement portion,
The non-embedded portion arrangement portion includes a first tapered portion that is gradually reduced in diameter along a predetermined direction on an outer surface portion thereof, and is formed outward from the inner surface portion of the non-embedded portion arrangement portion. It has a thin part formed so that it can be squeezed at a predetermined depth,
The outer member includes a second tapered portion that is gradually reduced in diameter along the predetermined direction on the inner surface thereof.
When the inner member moves in the predetermined direction with respect to the outer member, the second tapered portion of the inner surface portion of the outer member and the first surface of the outer surface portion of the non-embedded portion disposition portion . 1 in contact with the tapered portion, and in this state, the non-embedded portion arranged in the non-embedded portion arranging portion is pressed by the inner surface portion of the non-embedded portion arranged portion, thereby The relative angle between the member and the holding portion is fixed, and the concave portion formed on the outer surface of the non-embedded portion can be locked to the end portion of the thin portion of the non-embedded portion arrangement portion. It is configured as described above.

The invention according to claim 2 is the spinal fixation device according to claim 1 ,
The non-embedded portion arrangement portion is divided into a plurality of circumferential directions around an axis along the predetermined one direction,
When the inner member moves in the predetermined direction with respect to the outer member, the non-embedded portion arrangement portion is arranged on the outer side so as to reduce the interval between the separated portions of the non-embedded portion arrangement portion. The non-embedded portion is pressed by the inner surface portion of the non-embedded portion arrangement portion by being tightened by the inner surface portion of the member.

The invention according to claim 3 is the spinal fixation device according to claim 1 or 2,
The inner member is
A rod arrangement part provided on the opposite side to the side where the non-embedding part arrangement part is provided, and further comprising a rod arrangement part on which the rod is arranged;
When the rod disposed in the rod placement portion is pressed in the predetermined direction, the inner member moves relative to the outer member in the predetermined direction, and the inner surface portion of the outer member moves. The second taper-shaped portion and the first taper-shaped portion of the outer surface portion of the non-embedded portion arrangement portion are in contact with each other.

The invention according to claim 4 is the spinal fixation device according to claim 3 ,
The outer member is
A fixing screwed portion into which a fixing screw for fixing the rod arranged in the rod arrangement portion is screwed;
The fixing screw is screwed into the fixing threaded portion so that the rod is pressed and fixed in the predetermined direction at the tip of the fixing screw. It is said.

The invention according to claim 5 is the spinal fixation device according to claim 4 ,
The fixing member is configured to be able to release the screwing between the fixing screwed portion and the fixing screw while fixing the relative angle between the embedded member and the holding portion.

Moreover, invention of Claim 6 is a spinal fixation apparatus as described in any one of Claims 1-5 ,
The embedded member is characterized in that the non-embedded portion is configured to be detachable from the non-embedded portion arrangement portion.

The invention according to claim 7
And vertebrate fixing device, a spinal fixation system comprising a solid and a constant release device, a
The spinal fixation device comprises:
It is connected to the rod to fix the spine,
A long implant member partially embedded in the vertebrae constituting the spine;
A holding portion capable of holding the embedded member and the rod,
The holding part is
An inner member comprising a non-implanted portion placement portion in which a non-implant portion that is not embedded in the vertebra of the implant member is disposed;
An outer member provided on the outer side of the inner member, and having an inner surface portion that can come into contact with an outer surface portion of the non-embedded portion arrangement portion,
In a state where the inner surface portion of the outer member and the outer surface portion of the non-embedded portion arrangement portion are in contact with each other, the non-embedded portion arranged in the non-embedded portion arrangement portion is changed to the non-embedded portion arrangement portion. It is configured to press the inner surface portion to fix the relative angle between the embedded member and the holding portion,
The fixing release device is
The fixing of the relative angle between the embedded member and the holding part is released,
A positioning member that contacts and positions an end of the outer member opposite to the embedded member;
A screwing member to be screwed into a release screwed part provided on the side opposite to the side on which the non-embedded part arrangement part of the inner member is provided,
When the fixing member is positioned with respect to the outer member by the positioning member, the screw member is screwed into the release screwed portion of the inner member, so that the inner member is moved to the outer member. It is configured to move in a direction opposite to the predetermined one direction with respect to the member, and to release contact between the inner surface portion of the outer member and the outer surface portion of the non-embedded portion arrangement portion. .

  According to the present invention, the relative angle between the bone screw and the holding portion can be appropriately fixed with a simpler configuration.

It is a perspective view showing a schematic structure of a spinal fixation device illustrated as a preferred embodiment to which the present invention is applied. FIG. 2 is an exploded perspective view of the spinal fixation device of FIG. 1. It is sectional drawing of the spinal fixation apparatus in the III-III line of FIG. It is a figure which shows the inner member of the holder part which comprises the spinal fixation apparatus of FIG. It is a figure which shows the outer member of the holder part which comprises the spinal fixation apparatus of FIG. It is a figure which shows the screw for fixation which comprises the spinal fixation apparatus of FIG. It is a figure explaining the fixing method of the relative angle of the bone screw which comprises the spinal fixation apparatus of FIG. 1, and a holder part. It is a figure explaining the usage method of the said spinal fixation apparatus in the state with which the relative angle of the bone screw and holder part which comprises the spinal fixation apparatus of FIG. 1 was fixed. 1 is an exploded perspective view of a fixing release device exemplified as a preferred embodiment to which the present invention is applied. FIG. 10 is a one-side cross-sectional view illustrating the unlocking of the relative angle between the bone screw and the holder using the unlocking device of FIG. 9.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.
FIG. 1 is a perspective view showing a schematic configuration of a spinal fixation device 100 exemplified as a preferred embodiment to which the present invention is applied. 2 is an exploded perspective view of the spinal fixation device 100, and FIG. 3 is a cross-sectional view of the spinal fixation device 100 taken along line III-III in FIG.
In the following description, in a state where the spinal fixation device 100 is attached to the vertebra B of the spine V (see FIG. 8), the direction along the extending direction of the spine V (the alignment direction of the vertebra B) is defined as the Y-axis direction. One direction substantially perpendicular to the Y-axis direction and substantially parallel to the left-right direction of the human body is taken as the X-axis direction, and one direction (vertical direction) substantially perpendicular to the X-axis direction and the Y-axis direction is taken as the Z-axis direction.

The spinal fixation device 100 according to the present embodiment is substantially fixed by fixing two to each of a plurality of vertebrae B arranged in the Y-axis direction in order to fix, correct and stabilize the spine V such as a lumbar vertebra. Two cylindrical rods R are arranged along the spine V.
Specifically, as shown in FIGS. 1 to 3, the spinal fixation device 100 includes a bone screw 1 screwed into the vertebra B, a holder portion 2 to which the bone screw 1 and the rod R are attached and fixed, A fixing screw 3 to be screwed into the holder portion 2 is provided.

  The bone screw 1 is at least partially embedded in the vertebra B. Specifically, the bone screw 1 is formed in a long shape so as to be along the embedding direction (for example, the Z-axis direction), and has a screw main body portion 11 that is screwed into the vertebra B. A screw head that is not embedded in the vertebra B (non-embedded) on one end side in the longitudinal direction of the screw main body 11, that is, on the skin side opposite to the vertebra B when the spinal fixation device 100 is attached to the spine V. ) 12 is formed.

  The screw head 12 is formed, for example, from a part obtained by cutting a sphere formed continuously with the screw main body 11 along a plane substantially orthogonal to the axial direction of the bone screw 1. In addition, a mounting portion 13 to which an implanting device (not shown) for rotating the bone screw 1 to be embedded in the vertebra B is attached to the plane portion opposite to the screw main body portion 11 of the screw head 12. ing.

A plurality of annular recesses 14 are provided on the outer peripheral surface of the screw head 12.
The plurality of recesses 14 are formed so as to extend in the circumferential direction around the central axis of the bone screw 1. Specifically, the plurality of recesses 14,... Are formed by a predetermined number of bone screws 1 on the screw main body 11 side and the attachment portion 13 side from the substantially central portion in the axial direction of the bone screw 1 of the screw head 12. They are formed at predetermined intervals in the axial direction. That is, the vicinity of the axial direction of the bone screw 1 of the screw head 12 in the axial direction, in particular, the region near the mounting portion 13 from the central portion is formed in a curved surface shape without the concave portion 14 being formed.
Thereby, the contact area of the part formed in the curved surface shape of the outer peripheral surface of the screw head 12, and the curved surface part 211a (after-mentioned) of the screw head arrangement | positioning part 211 can be ensured more widely.

  The holder portion 2 is configured to be able to hold the bone screw 1 and the rod R as a holding portion. Specifically, the holder portion 2 includes an inner member 21 (see FIG. 4A and the like) in which the screw head 12 of the bone screw 1 is disposed, and an outer member 22 (see FIG. 4A). 5 (a) and the like).

4A is a perspective view showing the inner member 21 constituting the holder portion 2, and FIG. 4B is a cross-sectional view of the inner member 21 taken along line IV-IV in FIG. 4A.
As shown in FIGS. 4A and 4B, the inner member 21 is formed in a substantially cylindrical shape as a whole, for example, and a screw head 12 that is not embedded in the vertebra B of the bone screw 1 is disposed. A screw head arrangement portion (non-embedding portion arrangement portion) 211, an inner rod arrangement portion 212 in which the rod R is arranged on the inner side, and a release female screw portion 213 into which the screwing member 201 of the fixing release device 200 is screwed. Have.

  The screw head arrangement portion 211 is formed on one opening side which is the vertebra B side in a state where the spinal fixation device 100 in the inner member 21 is attached to the spine V. The screw head placement portion 211 includes an annular curved surface portion 211a formed by being curved in a substantially arc shape with a curvature substantially equal to the curvature of the screw head 12 of the bone screw 1, and the vertebra B side from the curved surface portion 211a. Have a plurality of separation piece portions 211b,.

The separation piece portion 211b is substantially equal to the skin side (upper side in FIG. 4B) from the opening end of the screw head placement portion 211 on the vertebra B side (lower side in FIG. 4B) along the Z-axis direction. And a predetermined number (for example, six) is cut out. That is, a plurality of screw head arrangement portions 211 are separated in the circumferential direction around the axis along the Z-axis direction by a plurality of separation piece portions 211b,.
Further, the inner surface portion of the separation piece portion 211b is formed to be curved in a substantially arc shape with a curvature substantially equal to the curvature of the screw head 12 of the bone screw 1.

In addition, a thin portion 211c is formed in a region between the base end portion of the separation piece portion 211b and the curved surface portion 211a. ing. Specifically, the boundary portion between the base end portion of the separation piece portion 211b and the curved surface portion 211a in the screw head arrangement portion 211 is scooped by a predetermined depth from the inner surface thereof in the direction substantially perpendicular to the Z-axis direction. In this way, the thin portion 211c is formed.
Thereby, the front end side of the plurality of separation piece portions 211b,... Can be displaced in a direction substantially orthogonal to the Z-axis direction with the base end side as an axis.

Further, in a state where the plurality of separation piece portions 211b,... Are not displaced, the inner diameter of the opening end on the vertebra B side of the separation piece portion 211b is formed smaller than the outer diameter of the screw head 12 of the bone screw 1. ing. On the other hand, in a state where the plurality of separation piece portions 211b,... Are displaced so as to open outward in a direction substantially perpendicular to the Z-axis direction, the inner diameter of the opening end on the vertebra B side of the separation piece portion 211b is the screw of the bone screw 1. The outer diameter of the head portion 12 is substantially equal to or larger than the outer diameter of the screw head portion 12.
Thus, the screws of the bone screw 1 so as to spread the plurality of separation pieces 211b,... From the opening end side on the vertebra B side of the plurality of separation pieces 211b,. By pushing the head 12, the screw head 12 can be placed inside the screw head placement portion 211. In this state, the screw head 12 is arranged so that the center of the screw head 12 of the bone screw 1 is positioned closer to the curved surface portion 211a than the proximal end portion of the separation piece 211b of the thin portion 211. The plurality of separation piece portions 211b are urged toward the inside in the direction substantially perpendicular to the Z-axis direction, and the screw head 12 is temporarily prevented from coming off.
On the other hand, by pulling out the screw head 12 of the bone screw 1 so that the plurality of separating pieces 211b,... Are spread outward in a direction substantially orthogonal to the Z-axis direction, 12 is removable.

Thus, the bone screw 1 is configured such that the screw head 12 of the bone screw 1 can be attached to and detached from the screw head arrangement portion 211 in a state where the relative angle with respect to the holder portion 2 is not fixed.
A method for fixing the relative angle between the bone screw 1 and the holder portion 2 will be described later.

Further, the outer surface portions 211d of the plurality of separation piece portions 211b,... Of the screw head arrangement portion 211 are formed in such a shape that the distal end side is inclined inward with respect to the proximal end side.
That is, of the inner member 21, the outer shape of the portion on the skin side of the separation piece portion 211b of the screw head arrangement portion 211 is formed in a substantially cylindrical shape having substantially the same outer diameter in a direction substantially perpendicular to the Z-axis direction. On the other hand, the outer surface portions 211d of the plurality of separation piece portions 211b,... Are formed in a tapered shape whose outer diameter is gradually reduced toward the vertebra B side opening along the Z-axis direction.

The inner rod placement portion 212 is formed on the side opposite to the screw head placement portion 211 in the inner member 21, that is, on the skin side opposite to the vertebra B side when the spinal fixation device 100 is attached to the spine V. . In addition, the inner rod placement portion 212 is formed by cutting a predetermined depth from the skin-side opening end of the inner member 21 toward the vertebra B along the Z-axis direction. Specifically, an inner rod in which the rod R is disposed on the inner side by cutting the side wall portion 214 of the inner member 21 having a cylindrical shape into a substantially “U” shape in a cross-sectional view (see FIG. 4B). An arrangement portion 212 is formed.
Further, the interval between the side wall portions 214 arranged substantially orthogonal to the Z-axis direction forming the inner rod arrangement portion 212 is substantially equal to the outer diameter of the rod R or slightly larger than the outer diameter of the rod R. ing. In addition, the inner surface of the end portion on the vertebra B side of the inner rod placement portion 212 is formed in a substantially semicircular shape with a curvature substantially equal to the outer peripheral surface of the rod R so as to be in contact with the outer peripheral surface of the rod R. Has been.

  In addition, a predetermined number (for example, four) of plate-like portions 215 for preventing the outer member 22 from coming off are formed at the skin side end of the inner rod placement portion 212. That is, the plate-like portion 215 is engaged with a guide groove 225 (see FIG. 5A, etc.) formed in the outer member 22 so that the inner member 21 and the outer member 22 extend along the Z-axis direction. It is possible to prevent the inner member 21 from coming out of the outer member 22 while guiding the relative movement.

The internal thread portion 213 for release is substantially “U” in cross-sectional view of the inner surfaces of the two side wall portions 214, 214 that are substantially orthogonal to the Z-axis direction forming the inner rod arrangement portion 212, that is, the side wall portion 214 of the inner member 21. It is formed in the part which is not cut out in the shape. Specifically, the release female thread portion 213 is formed so as to be seated at a predetermined depth from the inner surfaces of the two side wall portions 214 and 214 of the inner rod placement portion 212 on the outer side in a direction substantially perpendicular to the Z-axis direction. And have a predetermined pitch thread.
Then, when the fixation of the relative angle between the bone screw 1 and the holder portion 2 is released using the fixation release device 200 (described later), the release female screw portion 213 is used as the screwing member 201 of the fixation release device 200. The external thread part 201a formed in the outer peripheral surface of is screwed.
The release of the relative angle between the bone screw 1 and the holder portion 2 will be described later.

Fig.5 (a) is a perspective view which shows the outer member 22 which comprises the holder part 2, FIG.5 (b) is sectional drawing of the outer member 22 in the VV line | wire of Fig.5 (a).
As shown in FIGS. 5A and 5B, the outer member 22 is formed, for example, in a substantially cylindrical shape as a whole, and a storage portion 221 that stores the inner member 21 and a rod R disposed inside. And a fixing female screw portion 223 into which the fixing screw 3 is screwed.

The storage part 221 has an inner surface part 221 a having a shape substantially equal to the shape of the outer surface part of the inner member 21. Specifically, of the inner surface portion 221a of the storage portion 221, the portion on the opening side on the vertebra B side is shaped to be inclined inward corresponding to the plurality of separation piece portions 211b of the inner member 21. Is formed. That is, the inner surface portion 221a of the storage portion 221 is formed in a tapered shape whose inner diameter is gradually reduced toward the vertebra B side opening along the Z-axis direction.
Further, in the inner surface portion 221a of the storage portion 221, the portion on the skin side with respect to the tapered portion has an inner diameter in a direction substantially orthogonal to the Z-axis direction corresponding to the cylindrical portion of the inner member 21. It is formed to be substantially equal in the Z-axis direction.

Further, the length in the Z-axis direction of the inner surface portion 221 a of the storage portion 221 is longer than the length in the same direction of the inner member 21. Moreover, the inner diameter of the tapered portion on the opening side on the vertebra B side of the inner surface portion 221a of the storage portion 221 is substantially equal to the outer diameter of the plurality of separation piece portions 211b of the inner member 21, or the While being slightly larger than the outer diameter, the inner diameter of the inner surface portion 221a of the storage portion 221 on the skin side with respect to the tapered portion is substantially equal to the outer diameter of the cylindrical portion of the inner member 21. Alternatively, it is slightly larger than the outer diameter of the inner member 21.
Thereby, the inner member 21 accommodated in the accommodating portion 221 can move relative to the outer member 22 in the Z-axis direction while sliding the outer surface portion of the inner member 21 to the inner surface portion 221a of the accommodating portion 221. It has become. That is, the inner surface portion 221a of the storage portion 221 and the outer surface portion 211d of the screw head arrangement portion 211 of the inner member 21 can be contacted.

The outer rod placement portion 222 is formed by cutting out a predetermined depth from the skin-side opening end of the outer member 22 to the vertebra B side along the Z-axis direction. Specifically, the outer side rod 224 is arranged on the inner side by cutting the side wall 224 of the cylindrical outer member 22 into a substantially “U” shape in cross section (see FIG. 5B). An arrangement portion 222 is formed.
In addition, the interval between the side wall portions 224 arranged substantially orthogonal to the Z-axis direction of the outer rod arrangement portion 222 is substantially equal to the outer diameter of the rod R, or slightly larger than the outer diameter of the rod R. Yes. Further, the inner surface of the end portion on the vertebra B side of the outer rod arrangement portion 222 is formed to be curved in a substantially semicircular shape with substantially the same curvature as the outer peripheral surface of the rod R so as to be able to contact the outer peripheral surface of the rod R. Has been.

The internal thread portion 223 for fixing is substantially “U” -shaped in cross-sectional view of the inner surfaces of the two side wall portions 224 and 224 that are substantially orthogonal to the Z-axis direction forming the outer rod arrangement portion 222, that is, the side wall portion 224 of the outer member 22. It is formed in the part which is not cut out in the shape. Specifically, the fixing female screw portion 223 is formed continuously from the skin-side end portion of the storage portion 221, and is substantially orthogonal to the Z-axis direction from the inner surfaces of the two side wall portions 224 and 224 of the outer rod placement portion 222. A thread having a predetermined pitch formed so as to be squeezed at a predetermined depth on the outer side in the direction in which it is made.
And the external thread part 31 (after-mentioned) formed in the outer peripheral surface of the fixation screw 3 is screwed in the internal thread part 223 for fixation.

6A is a side view showing the fixing screw 3 viewed in a direction substantially perpendicular to the Z-axis direction (for example, the Y-axis direction), and FIG. 6B is a side view showing the fixing screw 3 in the Z-axis direction. It is a bottom view shown from the vertebra B side (lower side) in the direction.
As shown in FIG. 6A and FIG. 6B, the fixing screw 3 has a male screw portion 31 that is screwed with the fixing female screw portion 223 of the outer member 22 of the holder portion 2 on the outer peripheral surface thereof. Yes.

The male thread portion 31 has a thread with a predetermined pitch, and can be screwed with the thread of the female thread portion 223 for fixing. In addition, the front end portion (the front end portion of the incomplete screw thread portion) that becomes the screwing start position of the male screw portion 31 with respect to the fixing female screw portion 223 is recessed in the circumferential direction around the axis along the Z-axis direction. It is cut away (see FIG. 6B). Thereby, the male screw portion 31 of the fixing screw 3 can be easily screwed into the fixing female screw portion 223.
Note that the cross-sectional shapes of the male screw portion 31 and the corresponding fixing female screw portion 223 may be formed in a so-called dovetail shape, for example, so that the fastening by the fixing screw 3 can be made difficult to loosen. In particular, for example, when the lumbar vertebra is fixed using the spine fixing device 100, the cross-sectional shape of the fixing female screw portion 223 is preferably formed in a dovetail shape.

  Further, a rotation member attachment portion 32 to which a predetermined rotation member such as a screw driver for rotating the fixation screw 3 is attached is provided at the skin side end of the fixation screw 3 (FIG. 3 and the like). reference).

Further, when the fixing screw 3 is screwed into the fixing female screw portion 223 of the outer member 22, the inner rod placement portion 212 and the outer rod placement are arranged at the flat portion (tip portion) 33 on the vertebra B side of the fixing screw 3. The rod R arranged in the portion 222 is configured to be pressed and fixed to the Z-axis direction vertebra B side (predetermined one direction).
That is, in a state where the predetermined rotating member is attached to the rotating member attaching portion 32, the fixing screw 3 rotates in a predetermined direction around the axis along the Z-axis direction, whereby the male screw portion of the fixing screw 3 is obtained. 31 is screwed into the fixing female screw portion 223. The flat portion 33 of the fixing screw 3 comes into contact with the surface of the outer peripheral surface of the rod R facing the skin side, and the rod R is pressed toward the vertebra B side, whereby the inner rod placement portion 212 and the outer rod The rod R is fixed to the holder portion 2 by the arrangement portion 222 and the fixing screw 3 (see FIG. 1 and the like).

At this time, the rod R arranged in the inner rod placement portion 212 is pressed toward the Z-axis direction vertebra B, so that the inner member 21 moves relative to the outer member 22 toward the Z-axis direction vertebra B. The inner surface portion 221a on the vertebra B side of the storage portion 221 of the outer member 22 and the outer surface portions 211d of the plurality of separation piece portions 211b of the screw head placement portion 211 are in contact with each other and placed on the screw head placement portion 211. The screw head 12 of the bone screw 1 is pressed by the inner surface of the screw head arrangement portion 211 (see FIG. 7B).
That is, when the rod R is not pressed to the Z-axis direction vertebra B side by the fixing screw 3, the outer peripheral surface of the rod R contacts the inner surface of the end portion of the inner rod placement portion 212 of the inner member 21 on the vertebra B side. However, it is in the state which is not contacting the inner surface of the edge part by the side of the vertebra B of the outer side rod arrangement | positioning part 222 of the outer side member 22 (refer Fig.7 (a)). In this state, when the rod R is pressed toward the Z-axis direction vertebra B by the fixing screw 3, the inner member 21 is moved toward the Z-axis direction vertebra B side with respect to the outer member 22 via the inner rod placement portion 212. Move relative. When the outer peripheral surface of the rod R pressed by the fixing screw 3 comes into contact with the inner surface of the end portion on the vertebra B side of the outer rod placement portion 222, the relative movement of the inner member 21 with respect to the outer member 22 stops.

Further, the inner member 21 moves relative to the outer member 22 in the Z-axis direction vertebra B side, so that the plurality of separation piece portions 211b of the screw head arrangement portion 211 are in the storage portion 221 of the outer member 22. The separation piece portion 211b is pushed into a portion having an inner diameter smaller than the outer diameter. Accordingly, the outer surface portion 211d of the screw head arrangement portion 211 of the inner member 21 is tightened by the inner surface portion 221a of the storage portion 221 so as to narrow the interval between the plurality of separation piece portions 211b,. The screw head 12 of the bone screw 1 is pressed toward the center direction on the inner surface of the curved surface portion 211a and the separation piece portion 211b.
Specifically, the intervals between the plurality of separation piece portions 211b,... Are narrowed so that the screw heads 12 of the bone screw 1 are opposed to each other in the radial direction among the plurality of separation piece portions 211b,. It will be in the state which pressed the said screw head 12 with what is to be performed. Further, when the screw head 12 is pressed by the plurality of separation pieces 211b,..., A force is applied in the direction opposite to the relative movement direction of the inner member 21 (upward direction in FIG. 7B). The part 12 is pressed against the curved surface part 211a (see FIG. 7B). Thereby, the part formed in the curved surface shape of the outer peripheral surface of the screw head 12 is in contact with the curved surface portion 211a, and the concave portion 14 on the outer peripheral surface of the screw head 12 includes a plurality of separation piece portions 211b. ,... Are engaged with the edge on the vertebra B side, the end on the separation piece 211b side of the thin portion 211, the end on the curved surface 211a side of the thin portion 211c, and the like.

  In this way, the screw head 12 of the bone screw 1 arranged in the screw head arrangement portion 211 in the state where the inner surface portion 221a of the outer member 22 and the outer surface portion 211d of the screw head arrangement portion 211 are brought into contact with each other. The relative angle between the bone screw 1 and the holder portion 2 is appropriately fixed by pressing with the inner surface portion of the arrangement portion 211. In this state, it is possible to maintain a state in which the relative angle between the bone screw 1 and the holder portion 2 is fixed even if the screwing between the fixing female screw portion 223 and the fixing screw 3 is released (see FIG. 7 (c)).

  In addition, each part which comprises the said spinal fixation apparatus 100, ie, the bone screw 1, the holder part 2, and the fixing screw 3, is comprised from medical materials, such as an alloy and stainless steel etc. which contain titanium etc. in a predetermined ratio, for example. Yes.

<Spine fixation method>
Next, a method for fixing the spine V using the spinal fixation device 100 will be described in detail with reference to FIGS. 7 and 8.
FIG. 7A to FIG. 7C are diagrams illustrating a method for fixing the relative angle between the bone screw 1 and the holder portion 2. FIG. 8 is a diagram illustrating a method of using the spinal fixation device 100 in a state where the relative angle between the bone screw 1 and the holder portion 2 is fixed.

First, the bone screw 1 is implanted into the vertebra B of the spine V using an implantation device (not shown). Specifically, the implanting device is attached to the attachment portion 13 of the bone screw 1 and the bone screw 1 is rotated in a predetermined direction, thereby being screwed into a predetermined screwing position of the vertebra B (see FIG. 8). . Here, two bone screws 1 are embedded in each of at least two vertebras B and B arranged in the Y-axis direction at predetermined intervals in the X-axis direction.
FIG. 8 schematically shows a state in which the bone screws 1 of the spinal fixation device 100 are embedded in each of the two vertebrae B and B.

Next, the holder part 2 is attached to the bone screw 1. Specifically, the screw head placement portion is formed by pushing the screw head 12 of the bone screw 1 so as to spread the plurality of separation pieces 211b of the inner member 21 outward in a direction substantially orthogonal to the Z-axis direction. The screw head 12 is disposed inside 211. Thereby, the bone screw 1 and the holder part 2 will be in the connected state.
The bone screw 1 and the holder 2 may be connected before the bone screw 1 is embedded in the vertebra B. That is, the bone screw 1 may be embedded in the vertebra B of the spine V while the bone screw 1 and the holder portion 2 are connected.

  Subsequently, the rod R is arranged inside the inner rod arrangement portion 212 and the outer rod arrangement portion 222 (see FIG. 7A). Specifically, the rod R is disposed inside the inner rod placement portion 212 and the outer rod placement portion 222 of each spinal fixation device 100 corresponding to at least two vertebrae B arranged in the Y-axis direction.

Then, the fixing screw 3 is screwed into the fixing female screw portion 223 of each spinal fixation device 100 with a predetermined torque so that the flat portion 33 of the fixing screw 3 faces the skin side of the outer peripheral surface of the rod R. The rod R is pressed to the vertebra B side via the inner rod placement portion 212 in contact with the contact surface.
As a result, the inner member 21 moves relative to the outer member 22 in the Z-axis direction vertebra B side via the inner rod placement portion 212. At this time, the plurality of separation piece portions 211b of the screw head arrangement portion 211 are pushed into a portion having an inner diameter smaller than the outer diameter of the separation piece portion 211b in the storage portion 221 of the outer member 22. Then, the outer surface portions 211d of the plurality of separation piece portions 211b,... Of the screw head arrangement portion 211 are fastened by the inner surface portion 221a of the storage portion 221, and the screw head 12 of the bone screw 1 on the inner surface portion of the screw head arrangement portion 211 Is pressed toward the center direction.
When the outer peripheral surface of the rod R comes into contact with the inner surface of the end portion on the vertebra B side of the outer rod arrangement portion 222, the relative movement of the inner member 21 with respect to the outer member 22 stops. In this state, the relative angle between the bone screw 1 and the holder portion 2 is fixed (see FIG. 7B).

In the state where the screw head 12 of the bone screw 1 is pressed toward the center direction on the inner surface of the screw head arrangement portion 211 as described above, the screw engagement between the fixing female screw portion 223 and the fixing screw 3 is released. Even if this is done, it is possible to maintain a state in which the relative angle between the bone screw 1 and the holder portion 2 is fixed (see FIG. 7C).
Thereby, when adjusting the distance between the vertebra B so that any one spinal fixation device 100 is moved in the Y-axis direction with respect to the other spinal fixation devices 100, the bone screw 1 and the holder portion 2 can be adjusted. Even when a large load is applied, the relative angle between the bone screw 1 and the holder portion 2 does not change (see FIG. 8).

  After the distance between the vertebra B is adjusted, the fixing screw 3 is screwed into the fixing female screw portion 223 again, so that the spinal fixation device 100 is attached and fixed to the rod R at a desired position. .

Next, a method of releasing the relative angle between the bone screw 1 and the holder portion 2 will be described with reference to FIGS. 9 and 10.
FIG. 9 is an exploded perspective view of the fixing release device 200. 10 (a) and 10 (b) are one-side cross-sectional views for explaining the unlocking of the relative angle between the bone screw 1 and the holder part 2 using the fixing / unlocking device 200. FIG.

First, the fixing release device 200 will be described with reference to FIG.
As shown in FIG. 9, the fixation releasing device 200 includes a screwing member 201 screwed into the releasing female screw part 213, and a cylindrical positioning member 202 containing the screwing member 201.

The screwing member 201 is formed in a substantially cylindrical shape that is long in a predetermined direction, a male screw portion 201a is formed at one end portion, and a gripping portion 201b is provided at the other end portion.
The male screw portion 201a has a screw thread with a predetermined pitch and can be screwed with the screw thread of the release female screw portion 213.
The gripper 201b is gripped by a user who uses the fixation release device 200.

  The positioning member 202 is positioned in contact with the skin side end of the outer member 22. Specifically, the positioning member 202 is formed in a substantially cylindrical shape having a length substantially equal to the portion of the screwing member 201 formed in a substantially cylindrical shape, and has an inner rod placement portion 212 and an outer rod placement portion 222 at one end. And an abutting portion 202b that abuts against the skin-side end portion of the outer member 22 are formed.

  The engaging portion 202a is formed in a substantially “U” shape in sectional view, corresponding to the inner shape of the inner rod placement portion 212. Specifically, by cutting out the side wall portion of the cylindrical positioning member 202, two engagement portions 202a having a substantially “U” shape in cross section are formed in a direction substantially orthogonal to the Z-axis direction. A contact portion 202b is formed between the two engagement portions 202a and 202a.

The length of the engaging portion 202a in the axial direction of the positioning member 202, that is, the length from the contact portion 202b to the distal end of the engaging portion 202a on the spinal fixation device 100 side is larger than the depth of the outer rod placement portion 222. It is getting shorter. Therefore, in a state where the positioning member 202 is attached so that the contact portion 202b is in contact with the skin-side end portion of the outer member 22, the distal end portion of the engagement portion 202a is on the vertebra B side of the outer rod placement portion 222. It is made not to contact the inner surface of the edge part (refer FIG. 10 (a) and FIG.10 (b)).
In addition, the end of the engagement portion 202a on the spinal fixation device 100 side has a substantially arc shape with a curvature substantially equal to the inner surface so as to be in contact with the inner surface of the end of the inner rod placement portion 212 on the vertebra B side. It is curved.
In addition, the thickness of the engaging portion 202a in the direction substantially orthogonal to the axial direction is thicker than the thickness of the outer rod placement portion 222 in the same direction. It is substantially equal to a value obtained by adding the thicknesses in the same direction of the rod arrangement portion 212 or slightly smaller than this value.

  The fixation release device 200 configured as described above constitutes a spinal fixation system to which the present invention is applied together with the spinal fixation device 100.

<Unlocking method>
In the fixation releasing method described below, it is assumed that the fixing screw 3 and the rod R are removed from the holder portion 2 of the spinal fixation device 100 in advance. Further, it is assumed that the screwing member 201 is disposed inside the positioning member 202.

  First, the positioning member 202 is fixed to the spine so that the engagement portion 202a is disposed inside the inner rod placement portion 212 and the outer rod placement portion 222, and the abutment portion 202b is in contact with the skin side end of the outer member 22. Attach to device 100. Thereby, the said fixing release apparatus 200 will be in the state positioned with respect to the outer side member 22 (refer Fig.10 (a)).

Then, by rotating the screwing member 201 on which the gripping part 201b is gripped by the user in a predetermined direction with respect to the positioning member 202, the male screw part 201a of the screwing member 201 is screwed into the female screw part 213 for release. . Thereby, the inner member 21 is attracted to the fixing release device 200 side, that is, the inner member 21 moves to the skin side in the Z-axis direction with respect to the outer member 22, and the screw head is arranged by the inner surface portion 221 a of the storage portion 221. The tightening of the outer surface portion 211d of the plurality of separation piece portions 211b of the portion 211 is released (see FIG. 10B).
As a result, the contact between the inner surface portion 221a of the outer member 22 and the outer surface portion 211d of the screw head arrangement portion 211 is released, and the pressing of the screw head 12 of the bone screw 1 by the inner surface portion of the screw head arrangement portion 211 is released. In this state, the fixing of the relative angle between the bone screw 1 and the holder portion 2 is released.

As described above, according to the spinal fixation device 100 of the present embodiment, the holder portion 2 includes the inner member 21 including the screw head placement portion 211 on which the screw head 12 of the bone screw 1 is placed, and the screw head placement. An outer member 22 having an inner surface portion 221a that can come into contact with the outer surface portion 211d of the portion 211, and the inner surface portion 221a of the outer member 22 and the outer surface portion 211d of the screw head arrangement portion 211 are in contact with each other. Since the screw head 12 of the bone screw 1 is pressed by the inner surface portion 221a of the screw head arrangement portion 211, the relative angle between the bone screw 1 and the holder portion 2 is fixed. A member (ring or the like) for fixing the angle between the bone screw 1 and the holder portion 2 in the technology is not required, and the relative angle between the bone screw 1 and the holder portion 2 is appropriately fixed with a simpler configuration. be able to. In particular, the relative angle between the bone screw 1 and the holder portion 2 is more firmly fixed by pressing the screw head 12 of the bone screw 1 toward the center direction on the inner surface of the screw head arrangement portion 211. be able to.
As a result, it is possible not only to suppress the increase in the number of parts and the complexity of the device configuration of the spinal fixation device 100, but also to suppress the deterioration in handling property and cost increase of the spinal fixation device 100.

Further, the rod R arranged in the inner rod placement portion 212 of the inner member 21 is pressed in a predetermined direction (Z-axis direction vertebra B side), whereby the inner member 21 is moved in the predetermined direction to the outer member 22. Since the inner surface portion 221a of the outer member 22 and the outer surface portion 211d of the screw head arrangement portion 211 are in contact with each other, the rod R is fixed to a predetermined amount. The inner surface portion 221a of the outer member 22 and the outer surface portion 211d of the screw head arrangement portion 211 are brought into contact with each other only by pressing in one direction, and the screw head 12 of the bone screw 1 is pressed by the inner surface portion of the screw head arrangement portion 211. State. Specifically, when the inner member 21 moves with respect to the outer member 22 in a predetermined direction, the screw head arrangement portion 211 of the outer member 22 reduces the interval between the plurality of separation piece portions 211b,. The screw head 12 of the bone screw 1 can be pressed by the inner surface portion of the screw head arrangement portion 211 by being tightened by the inner surface portion 221a.
At this time, the fixing screw 3 is screwed into the fixing female screw portion 223 of the outer member 22 so that the rod R is pressed and fixed in a predetermined direction at the tip end portion of the fixing screw 3. Therefore, the rod R can be pressed in a predetermined direction only by screwing the fixing screw 3 into the fixing female screw portion 223, and the screw head 12 of the bone screw 1 can be screwed with a simpler configuration. It can be set as the state pressed by the inner surface part of the head arrangement | positioning part 211. FIG. Furthermore, in this state, even if the fixing screw 3 is removed from the fixing female screw part 223 and the screwing between the fixing female screw part 223 and the fixing screw 3 is released, the bone screw 1 and the holder part 2 It is possible to maintain a state in which the relative angle of each is fixed.

  In addition, the bone screw 1 is configured so that the screw head 12 can be attached to and detached from the screw head placement portion 211 in a state where the relative angle with respect to the holder portion 2 is not fixed. Embedding can be performed more flexibly. That is, after the bone screw 1 not held by the holder portion 2 is embedded in the vertebra B, the screw head 12 may be attached to the screw head arrangement portion 211, or the screw head 12 may be attached to the screw head. The bone screw 1 attached to the placement unit 211 may be embedded in the vertebra B.

Further, by using the fixing release device 200 having the positioning member 202 and the screwing member 201, the relative angle fixing between the bone screw 1 and the holder portion 2 can be released more easily. That is, in a state where the relative angle between the bone screw 1 and the holder portion 2 is fixed, the fixing release device 200 is positioned with respect to the outer member 22 by the positioning member 202, and the screwing member 201 is moved to the inner member 21. By screwing into the release female screw portion 213, the inner member 21 is moved in a direction opposite to the predetermined one direction (Z-axis direction skin side) with respect to the outer member 22, and the inner surface portion 221a of the outer member 22 and the screw head arrangement are arranged. Contact with the outer surface portion 211d of the portion 211 can be released. Thereby, the pressing of the screw head 12 of the bone screw 1 by the inner surface portion of the screw head arrangement portion 211 can be released, and the fixation of the relative angle between the bone screw 1 and the holder portion 2 can be released.
Therefore, for example, when the relative angle between the bone screw 1 and the holder portion 2 is fixed, and then it is desired to adjust the angle again, by using the fixing release device 200, the bone screw 1 and the holder portion 2 The relative angle can be fixed more easily, and the angle can be readjusted more easily.

The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
For example, in the above embodiment, the rod R is pressed in a predetermined direction with the tip of the fixing screw 3 to contact the inner surface 221a of the outer member 22 and the outer surface 211d of the screw head arrangement portion 211. However, the present invention is not limited to this example, and the bone screw 1 is in contact with the inner surface 221a of the outer member 22 and the outer surface 211d of the screw head arrangement portion 211. Any configuration can be used as appropriate as long as the screw head 12 is pressed by the inner surface portion 221a of the screw head arrangement portion 211.

  Moreover, in the said embodiment, although the fixing release apparatus 200 of the structure in which the positioning member 202 includes the screwing member 201 was illustrated, the structure of the fixing release apparatus 200 is an example, and is not restricted to this. These can be arbitrarily changed as appropriate. Further, the fixing release device 200 may include a mechanism that prevents the screwing member 201 from coming off from the positioning member 202.

Moreover, in the said embodiment, although what was made into the substantially cylindrical shape with a substantially equal cross-sectional shape was illustrated as the rod R, the external shape of the rod R is not restricted to this.
Here, when the outer shape of the rod R is other than a columnar shape, the vertebra side surfaces of the inner rod arrangement portion 212 and the outer rod arrangement portion 222 are matched with the shape of the outer circumference surface of the rod R to at least the outer circumference surface. What is necessary is just to form in the shape along a part.

  In addition, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

100 Spinal Fixation Device 1 Bone Screw (Implanted Member)
12 Screw head (non-embedded part)
2 Holder part (holding part)
21 Inner member 211 Screw head arrangement part (non-embedding part arrangement part)
211b Separating piece portion 211d Outer surface portion 212 Inner rod placement portion 213 Release female screw portion (release screwed portion)
22 Outer member 221 Storage portion 221a Inner surface portion 223 Fixing female screw portion (fixing screwed portion)
3 Fixing screw 200 Unlocking device 201 Screwing member 201a Male thread portion 202 Positioning member R Rod

Claims (7)

A spinal fixation device connected to a rod to fix the spine,
A long implant member partially embedded in the vertebrae constituting the spine;
A holding portion capable of holding the embedded member and the rod,
The holding part is
An inner member comprising a non-implanted portion placement portion in which a non-implant portion that is not embedded in the vertebra of the implant member is disposed;
An outer member provided on the outer side of the inner member, and having an inner surface portion that can come into contact with substantially the entire outer surface portion of the non-embedded portion arrangement portion,
The non-embedded portion arrangement portion includes a first tapered portion that is gradually reduced in diameter along a predetermined direction on an outer surface portion thereof, and is formed outward from the inner surface portion of the non-embedded portion arrangement portion. It has a thin part formed so that it can be squeezed at a predetermined depth,
The outer member includes a second tapered portion that is gradually reduced in diameter along the predetermined direction on the inner surface thereof.
When the inner member moves in the predetermined direction with respect to the outer member, the second tapered portion of the inner surface portion of the outer member and the first surface of the outer surface portion of the non-embedded portion disposition portion . 1 in contact with the tapered portion, and in this state, the non-embedded portion arranged in the non-embedded portion arranging portion is pressed by the inner surface portion of the non-embedded portion arranged portion, thereby The relative angle between the member and the holding portion is fixed, and the concave portion formed on the outer surface of the non-embedded portion can be locked to the end portion of the thin portion of the non-embedded portion arrangement portion. It is comprised so that the spine fixation apparatus characterized by the above-mentioned. The non-embedded portion arrangement portion is divided into a plurality of circumferential directions around an axis along the predetermined one direction,
When the inner member moves in the predetermined direction with respect to the outer member, the non-embedded portion arrangement portion is arranged on the outer side so as to reduce the interval between the separated portions of the non-embedded portion arrangement portion. The spinal fixation device according to claim 1, wherein the spinal fixation device is pressed by the inner surface portion of the member and pressed by the inner surface portion of the non-implanted portion arrangement portion. The inner member is
A rod arrangement part provided on the opposite side to the side where the non-embedding part arrangement part is provided, and further comprising a rod arrangement part on which the rod is arranged;
When the rod disposed in the rod placement portion is pressed in the predetermined direction, the inner member moves relative to the outer member in the predetermined direction, and the inner surface portion of the outer member moves. 3. The spinal fixation device according to claim 1, wherein the second tapered portion is in contact with the first tapered portion of the outer surface portion of the non-embedded portion arrangement portion. The outer member is
A fixing screwed portion into which a fixing screw for fixing the rod arranged in the rod arrangement portion is screwed;
The fixing screw is screwed into the fixing threaded portion so that the rod is pressed and fixed in the predetermined direction at the tip of the fixing screw. The spinal fixation device according to claim 3.   The screwing between the fixing screwed portion and the fixing screw can be released while the relative angle between the embedded member and the holding portion is fixed. 4. The spinal fixation device according to 4.   The spinal fixation device according to any one of claims 1 to 5, wherein the embedded member is configured such that the non-implanted part can be attached to and detached from the non-implanted part disposition part. A spinal fixation system comprising a spinal fixation device and a fixation release device,
The spinal fixation device comprises:
It is connected to the rod to fix the spine,
A long implant member partially embedded in the vertebrae constituting the spine;
A holding portion capable of holding the embedded member and the rod,
The holding part is
An inner member comprising a non-implanted portion placement portion in which a non-implant portion that is not embedded in the vertebra of the implant member is disposed;
An outer member provided on the outer side of the inner member, and having an inner surface portion that can come into contact with an outer surface portion of the non-embedded portion arrangement portion,
In a state where the inner surface portion of the outer member and the outer surface portion of the non-embedded portion arrangement portion are in contact with each other, the non-embedded portion arranged in the non-embedded portion arrangement portion is changed to the non-embedded portion arrangement portion. It is configured to press the inner surface portion to fix the relative angle between the embedded member and the holding portion,
The fixing release device is
The fixing of the relative angle between the embedded member and the holding part is released,
A positioning member that contacts and positions an end of the outer member opposite to the embedded member;
A screwing member to be screwed into a release screwed part provided on the side opposite to the side on which the non-embedded part arrangement part of the inner member is provided,
When the fixing member is positioned with respect to the outer member by the positioning member, the screw member is screwed into the release screwed portion of the inner member, so that the inner member is moved to the outer member. It is configured to move in a direction opposite to the predetermined one direction with respect to the member, and to release the contact between the inner surface portion of the outer member and the outer surface portion of the non-embedding portion arrangement portion. Spinal fixation system.

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