JP5184971B2 - Spacer - Google Patents

Description

  The present invention relates to a spacer.

For example, as a treatment for cervical spondylotic myelopathy, posterior longitudinal ligament ossification, yellow ligament ossification, intervertebral disc herniation, etc., a median longitudinal split cervical vertebral laminoplasty is performed.
In midline longitudinal split laminoplasty, the midline (center) of the vertebral arch and spinous process is cut, and the vertebral arches on both sides are opened like a hinge with the midline as the boundary. Enlarge the tube. At this time, a spacer is inserted into a gap formed by cutting a vertebral arch or spinous process (see, for example, Patent Document 1).

In such median longitudinal split laminoplasty, the spinous process is separated from the vertebral arch with the ligaments, supraspinous / interspinous ligaments, and muscles attached, and the vertebrae are expanded. Return the protrusion to the center. Attempts have been made to attempt to unite the dissected spinous process with the enlarged vertebral arch.
However, when using conventional vertebral arch spacers, the position of the spinous process cannot be reliably maintained. Therefore, after the operation, the spinal process may be misaligned due to cervical flexion and extension, or bone fusion may be delayed. There was a problem that.

JP 2007-301244 A

  An object of the present invention is to provide a spacer that can reliably hold the position of the spinous process separated from the vertebral arch.

Such an object is achieved by the present inventions (1) to (15) below.
(1) The spinous process is separated from the vertebral arch, and the vertebral arch is cut at a portion where the spinous process is separated and inserted into a gap formed by cutting the vertebral arch to expand the spinal canal. A spacer used for
Two vertebral abutment surfaces with which both ends of the cut portion of the vertebral abutment are in contact with each other, a spinous process attachment surface for attaching the separated spinous process, and a penetration between the two vertebral abutment surfaces to the average inner diameter and a first through hole and the average inner diameter of said average inner diameter φ0.5~5mm greater than the first through-hole the second through hole of Fai0.3～3Mm,
A linear first fixing member is inserted into the first through-hole to fix the spinous process to the spinous process attachment surface, and a linear second fixing member to the second through-hole. The spacer is configured to be inserted and fixed in the gap in a state in which the two vertebral abutment surfaces are in contact with both ends of the portion where the vertebral arch is cut.

  As a result, the enlarged formation of the vertebral arch can be reliably performed, and the position of the separated spinous process can be reliably maintained.

  (2) The spacer according to (1), wherein the spacer is inserted into the gap formed between the both ends so that the spinous process attachment surface faces the outside of the vertebral arch.

  Thereby, an enlarged vertebral arch is formed by the patient's vertebra and the spacer, and as a result, the spinal canal is enlarged. Since the spinous process attachment surface is attached to the spinous process attachment surface, the patient's appearance after operation is more natural if it is inserted into the gap so that the spinous process attachment surface is on the outside. It will be something.

  (3) The spacer according to (1) or (2), wherein an area of the spinous process attachment surface is larger than an area of a cut surface of the spinous process.

  Accordingly, when the separated spinous process is to be bone-bonded with the spinous process attachment surface, it is possible to suitably prevent the positional displacement of the spinous process with respect to the spinous process attachment surface and to contact the spinous process attachment surface with the spinous process. Since the area increases, this bone fusion can be achieved early. As a result, the spinous process can be reliably and early fixed to the vertebral arch via the spacer.

  (4) In the state in which the spacer is inserted in the gap, the two end portions of the vertebral arch contact surface located outside the vertebral arch and the both end portions of the spinous process attachment surface are adjacent to each other The spacer according to any one of (1) to (3).

  (5) In the state where the spacer is inserted into the gap, the first through hole is located outside the vertebral arch with respect to the second through hole. The spacer described.

  Thereby, the separation distance with respect to the thickness direction of the spacer between the spinous process attachment surface and the first through hole is shortened, and displacement and loosening of the first fixing member can be more effectively prevented. Furthermore, since there are fewer portions where the first fixing member and the both ends of the part where the vertebral arch is cut are in direct contact, the bone fusion between the vertebral abutment surface and the both ends is made stronger. can do.

  (6) In the state where the spacer is inserted into the gap, the first through hole and the second through hole are arranged side by side from the patient's back to the abdomen. Thru | or the spacer in any one of (5).

  Thereby, since the spinous process and the spacer can be fixed without dispersing the fixing force by the first fixing member and the second fixing member, respectively, in the first fixing member and the second fixing member, It is possible to reliably prevent the deviation and loosening from occurring.

  (7) In any one of the above (1) to (6), each of the two vertebral arch contact surfaces is provided with an engaging portion that can be engaged with both ends of a portion where the vertebral arch is cut. The spacer described.

  This prevents the spacer from moving to the spinal canal side, and can reliably prevent the spinal nerve from being compressed by the spacer, so that safety is high.

  (8) The spacer according to (7), wherein the engaging portion is provided so as to protrude from the arch contact surface.

  This prevents the spacer from moving to the spinal canal side, and can reliably prevent the spinal nerve from being compressed by the spacer, so that safety is high.

  (9) The spacer according to (8), wherein the engaging portion is provided so as to form one flat surface continuous with the spinous process attachment surface.

  Thereby, the spacer can be inserted into the gap without the spinous process attachment surface protruding to the rear side of the vertebral arch.

  Thus, when the spacer is inserted in the gap without protruding the spinous process attachment surface to the back side of the vertebral arch, the spinous process attachment surface is adjusted without adjusting the height of the spinous process separated from the vertebral arch Even if attached to the spinous process, it can be returned to the spinous process attachment surface without increasing its height as compared with the adjacent spinous process. As a result, the patient's appearance after surgery can be made more natural and the patient's mental burden can be reduced, as well as ensuring that external pressure is applied alone to the attached spinous process. Therefore, peeling of the attached spinous process is preferably prevented.

  (10) The spacer according to any one of (7) to (9), wherein the engaging portion includes a notch or a hole through which at least one of the first fixing member and the second fixing member is inserted. .

  By inserting and locking the first fixing member in the notch or the hole, the spinous process can be fixed to the spacer more easily and reliably. Furthermore, it is possible to prevent the first fixing member from being displaced or loosened during and after the operation, and to maintain the fixed state of the spinous process reliably. Further, by inserting and locking the second fixing member in the notch or the hole, the spacer can be more easily and reliably fixed to the vertebral arch. Furthermore, it is possible to prevent the second fixing member from being displaced or loosened during and after the operation, and to maintain the fixed state of the spacer with certainty.

  (11) The spacer according to (10), wherein the notch or the hole is located in the vicinity of the opening of the first through hole.

  Thereby, the separation distance with respect to the thickness direction of the spacer between the notch or the hole and the first through hole is shortened, and displacement and loosening of the first fixing member can be more effectively prevented. Furthermore, since there are fewer portions where the first fixing member and the both ends of the part where the vertebral arch is cut are in direct contact, the bone fusion between the vertebral abutment surface and the both ends is made stronger. can do.

  (12) When the two contact surfaces are viewed from the front, the opening of the first through hole, the opening of the second through hole, and the notch or the hole are aligned in a straight line. The spacer according to (10) or (11) above.

  Thereby, since the spinous process and the spacer can be fixed without dispersing the fixing force by the first fixing member and the second fixing member, respectively, in the first fixing member and the second fixing member, It is possible to reliably prevent the deviation and loosening from occurring.

(13) The spacer according to any one of (1) to (12), wherein the spacer is made of a ceramic material.
Thereby, the spacer excellent in workability can be obtained.

(14) The spacer according to (13), wherein the ceramic material is made of a calcium phosphate compound.
Thereby, the spacer which has the outstanding biocompatibility can be obtained.

(15) The spacer according to (13) or (14), wherein the ceramic has a porosity of 0 to 90%.
This promotes the fusion of the spacer to the bone tissue.

  According to the present invention, the spinous process is fixed to the spinous process mounting surface by the linear first fixing member, and the spacer is fixed to the gap formed by cutting the vertebral arch by the linear second fixing member. As a result, the vertebral arch can be reliably enlarged and the position of the separated spinous process can be reliably maintained.

  Moreover, if the engaging part which can engage with the both ends of the site | part which cut | disconnected the vertebral arch was provided so that one flat surface continuous with the spinous process attachment surface which a spacer had might be comprised, it cut away from the vertebral arch Even if it is attached to the spinous process attachment surface without adjusting the height of the spinous process, it can be returned without increasing its height as compared with the adjacent spinous process. This not only makes the patient's appearance more natural after surgery, reduces the patient's mental burden, but also ensures that external pressure is applied alone to the attached spinous process. Since it can prevent, peeling of the attached spinous process is prevented suitably.

Hereinafter, the spacer of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<First Embodiment>
FIG. 1 is a view showing a first embodiment of a spacer of the present invention ((a) front view, (b) plan view, (c) side view), and FIGS. It is a figure for explaining laminoplasty step by step.

<< Medium longitudinal split-type laminoplasty >>
First, prior to describing the first embodiment of the spacer of the present invention, the median longitudinal split-type laminoplasty will be described with reference to FIGS. 2 to 6, the upper side is the patient's back side (rear), and the lower side is the patient's ventral side (front).

  As shown in FIG. 2, the vertebra 100 includes a vertebral body 110, a vertebral arch 120 that extends behind the vertebral body 110 (upper side in FIG. 2) and forms a spinal canal (vertebral foramen) 140, And a spinous process 130 protruding backward from the central portion.

  [1] First, as shown in FIG. 2, the spinous process 130 in the vertebra 100 is separated (cut) from the vertebral arch 120 so that a cutting plane 132 is formed at the cutting line 131.

  [2] Next, as shown in FIG. 3, the central portion (median portion) of the vertebral arch 120 from which the spinous processes 130 have been separated is cut using, for example, an air drill. Thereby, the cutting | disconnection edge part 120a, 120b (both ends) is formed in the site | part from which this vertebral arch 120 was cut | disconnected.

  Further, grooves 121a and 121b are formed on the outer side of the root portion of the vertebral arch 120 with the median plane 200 as a boundary, for example, using an air drill or the like.

  The depths of the grooves 121a and 121b are set such that only the outer plate is cut and the inner plate is not cut. The portions where the grooves 121a and 121b are formed are hinge portions (hinges) 122a and 122b.

  [3] Next, as shown in FIG. 4, the vertebral arch 120 is rotated around the hinges 122a and 122b, and the cut portion of the vertebral arch 120 is expanded. Thereby, the gap 150 is formed. As described above, the gap 150 is formed by cutting the vertebral arch 120.

  Further, through holes 123a and 123b through which the thread 302 for fixing the spacer 1 in the gap 150 is inserted in the cut ends 120a and 120b, respectively, in the post-process [5], for example, using an air drill or the like. (See FIG. 4).

  Further, in the next step [4], a through-hole 133 through which the thread 301 for fixing the spinous process 130 to the spacer 1 is inserted is formed near the cutting surface 132 of the cut spinous process 130 using, for example, an air drill or the like. (Not shown).

  If necessary, the cut ends 120a and 120b facing the gap 150 of the vertebral arch 120 are shaped.

  [4] Next, as shown in FIG. 5, the spinous process 130 separated in the step [1] is returned to the center (median) of the rear surface (spinous process attachment surface) 13 of the spacer 1, and then the spinous process is performed. A thread 301 as a fixing member (first fixing member) is inserted and tied (sewn) into the through hole 133 of the protrusion 130 and the through hole (first through hole) 51 of the spacer 1, thereby binding the spine. The protrusion 130 is fixed to the spacer 1 (rear surface 13). Thereby, when the spacer 1 to which the spinous process 130 is fixed is fixed in the gap 150 in the next step [5], the position of the spinous process 130 can be reliably held. Therefore, the spinous process 130 is prevented from being displaced with respect to the spacer 1, the patient's appearance after the operation becomes more natural, and the bone fusion between the spinous process 130 and the spacer 1 is quickly and reliably performed. Can be generated. As a result, physiological reconstruction can be achieved at an early stage, and postoperative external fixation period and exercise restriction period can be shortened.

  [5] Next, as shown in FIG. 6, the spacer 1 to which the spinous process 130 is fixed is inserted into the gap 150 so that the rear surface 13 faces outward, that is, the spinous process 130 faces outward. Thereafter, the thread 302 as a fixing member (second fixing member) is inserted into the through holes 123a and 123b provided in the cut ends 120a and 120b, respectively, and the through hole (second through hole) 52 of the spacer 1. The spacer 1 is fixed in the gap 150 by being inserted and tied (sewn). Thus, an enlarged vertebral arch 160 is formed by the patient's vertebral arch 120 and the spacer 1, and as a result, the spinal canal is expanded.

  As described above, the spacer 1 and the cut ends 120a and 120b are tied with the thread 302, and the spacer 1 is fixed in the gap 150, so that the spacer 1 can be attached to the vertebral arch 120 early after the operation. Misalignment can be prevented, and bone fusion between the cut ends 120a and 120b and the side surface 12 can be reliably caused.

  Further, in the present invention, the spinous process 130 is separated from the vertebral arch 120 with the ligaments, supraspinous / interspinous ligaments and muscle groups attached thereto, and the spinous processes 130 can be attached to the rear surface 13. The formed spinous process 130 can surely promote the bone fusion between the spacer 1 and the spinous process 130 and the bone fusion between the spacer 1 and the vertebral arch 120.

  Each fixing member (the first fixing member and the second fixing member) only needs to form a linear body, and is not limited to the threads 302 and 301 as described above. A linear body can also be used.

<< Spacer >>
Next, a first embodiment of the spacer of the present invention will be described with reference to FIG. 1 and FIG.

  In the following description, unless otherwise specified, the direction is specified based on the state in which the spacer 1 is inserted (attached) into the treatment site (gap 150) of the patient. That is, the patient's ventral side (vertebral canal 140 side) is called “front”, the dorsal side (opposite to the spinal canal 140) is called “rear”, the patient's head side is “up”, and the patient's leg side is “down”. "

  As shown in FIGS. 1 and 6, the spacer 1 according to the present embodiment engages with the spacer main body 2 inserted into the gap 150 and the cut ends (both ends) 120 a and 120 b of the vertebral arch 120. And an engaging portion 3.

  As shown in FIGS. 1 and 6, the spacer main body 2 has a substantially trapezoidal shape as a whole. The front surface 11 and the rear surface 13, the upper surface 14 and the lower surface 15, and the pair of side surfaces 12 are opposed to each other. The structure is surrounded mainly by. Each of these surfaces 11, 12, 13, 14, and 15 is a flat surface.

  By making the spacer body 2 have such a trapezoidal shape, the spinal canal 140 can be enlarged larger (wider) when inserted into the gap 150 formed by cutting the vertebral arch 120, It is possible to reliably prevent spinal nerve compression.

  In such a spacer main body 2, the posterior surface 13 constitutes a spinous process attachment surface for attaching the spinous process 130 separated from the vertebral arch 120. In this embodiment, the area of the rear surface 13 is larger than the area of the cut surface 132 of the spinous process 130. Accordingly, when the separated spinous process 130 is intended for bone fusion with the rear surface 13, the positional displacement of the spinous process 130 with respect to the rear surface 13 can be suitably prevented, and the contact area between the rear surface 13 and the spinous process 130 increases. Therefore, this bone fusion can be achieved at an early stage. As a result, the spinous process 130 can be fixed to the vertebral arch 160 that is expanded reliably and early via the spacer 1.

  The pair of (two) side surfaces 12 are contact surfaces with which the cut end portions (both end portions) 120a and 120b of the portion where the vertebral arch 120 is cut contact with the spacer 1 inserted into the gap 150, respectively. Configure.

  In addition, in such a spacer main body 2 of this embodiment, it has the structure which the edge part of the rear side of the two side surfaces 12 and the both ends of the rear surface 13 adjoin.

  As shown in FIGS. 1 and 6, the spacer main body 2 has a space between a pair of side surfaces (two vertebral abutment surfaces) 12 in the left-right direction of the spacer main body 2 (direction substantially orthogonal to the front-rear direction). A first through hole 51 and a second through hole 52 that penetrate therethrough are provided.

  The first through-hole 51 and the second through-hole 52 can be inserted with the above-described thread 301 and thread 302, respectively.

  As shown in FIG. 5, a through-hole 133 is formed in the vicinity of the cut surface 132 of the spinous process 130, and a thread 301 is inserted and tied (sewn) to the first through-hole 51 and the through-hole 133, thereby The protrusion 130 can be fixed to the rear surface 13. Accordingly, when the spacer 1 to which the spinous process 130 is fixed is fixed in the gap 150, the position of the spinous process 130 with respect to the rear surface 13 can be reliably held. Misalignment is prevented, and bone fusion between the spinous process 130 and the rear surface 13 (spacer 1) can be generated quickly and reliably.

  As shown in FIG. 6, through holes 123a and 123b are formed in the cut ends 120a and 120b of the vertebral arch 120, respectively, and a thread 302 is inserted into the second through hole 52 and the through holes 123a and 123b. By tying (stitching), the spacer 1 can be fixed to the vertebral arch 120 with the pair of side surfaces 12 in contact with the cut ends 120a and 120b. Thereby, it is possible to prevent the spacer 1 from being displaced with respect to the vertebral arch 120 early after the operation, and the cut ends 120a, 120b and It is possible to more reliably cause bone fusion between the two.

  In the present embodiment, the first through hole 51 is located outside the second through hole 52. Thereby, the separation distance with respect to the thickness direction of the spacer main body 2 of the rear surface 13 and the 1st through-hole 51 becomes short, and the shift | offset | difference and loosening of the thread | yarn 301 can be prevented more effectively. Furthermore, since the part which the thread | yarn 301 and the cutting | disconnection edge part 120a, 120b contact directly decreases, the bone fusion between the side surface 12 and the cutting | disconnection edge part 120a, 120b can be made stronger.

  Furthermore, as shown in FIG. 1C, the first through hole 51 and the second through hole 52 are arranged side by side from the rear side to the front side. Thereby, the spinous process 130 and the spacer 1 can be fixed without dispersing the fixing force by the yarns 301 and 302, so that the yarns 301 and 302 are reliably prevented from being displaced or loosened. be able to.

  Further, since the first through hole 51 and the second through hole 52 are provided independently, that is, the first through hole 51 and the second through hole 52 are not communicated with each other, the entire spacer 1 is provided. As a result, it is possible to prevent a decrease in mechanical strength.

  Furthermore, the total opening area of the first through hole 51 and the second through hole 52 on the side surface (contact surface) 12 is preferably about 0.1 to 20% of the area of the side surface 12. More preferably, it is about 1 to 5%. Thereby, the thread 301 and the thread 302 can be more reliably and easily inserted into the first through hole 51 and the second through hole 52, and the mechanical strength of the spacer body 2 (spacer 1) is reduced. Thus, the bone fusion between the side surface 12 and the cut end portions 120a and 120b can be caused earlier.

  In the configuration shown in the figure, the first through hole 51 and the second through hole 52 have a substantially circular cross-sectional shape, but for example, an ellipse, a rectangle, a square such as a square, a triangle, and the like. You can also

  The two end portions on the rear side of the spacer body 2, that is, the end portions on the rear side of the two side surfaces 12, are each composed of two plate-like flanges 31 projecting sideways from the spacer body 2. An engaging portion 3 is provided.

  When the spacer 1 is inserted into the gap 150, the two flanges 31 abut (engage) with the rear sides of the cut ends 120a and 120b at the site where the vertebral arch 120 is cut. Accordingly, the spacer 1 is prevented from moving to the spinal canal 140 (anterior) side, and compression of the spinal nerve by the spacer 1 can be surely prevented, so that safety is high.

  Further, as in the present embodiment, the flange 31 is configured to protrude from the spacer body 2 along the rear surface 13 configured by a plane, that is, the flange 31 and the rear surface 13 are configured by one flat surface. Is preferred. Thereby, the spacer 1 can be inserted into the gap 150 without the rear surface 13 projecting extremely rearward. That is, in the enlarged vertebral arch 160 composed of the patient's vertebral arch 120 and the spacer 1, it is possible to accurately prevent a portion projecting rearward from the portion composed of the spacer 1. .

  In this way, when the spacer 1 is inserted into the gap 150 without the rear surface 13 protruding rearward, it is attached to the rear surface 13 without adjusting the height of the spinous process 130 separated from the vertebral arch 120. Even so, it can be returned without increasing its height compared to the adjacent spinous processes. As a result, not only can the patient's appearance after surgery be more natural and the patient's mental burden can be reduced, but also external pressure can be applied to the attached spinous process 130 alone. Since it can prevent reliably, peeling of the attached spinous process 130 is prevented suitably.

  When the rear surface 13 protrudes rearward, the height of the adjacent spinous process and the height of the spinous process 130 can be adjusted by cutting the cut surface 132 of the separated spinous process 130 and adjusting its height. However, in this case, there is a problem that the operation time becomes longer and the burden on the patient increases because the process of cutting the cut surface 132 increases.

  Moreover, in this embodiment, each flange 31 is provided with the notch 32 in the approximate center part of the longitudinal direction, respectively. By inserting and locking the thread 301 into the notch 32, the spinous process 130 can be fixed to the spacer 1 more easily and reliably. Further, it is possible to prevent the thread 301 from being displaced or loosened during and after the operation, and the fixed state of the spinous process 130 can be reliably maintained. Further, by inserting and locking the thread 302 into the notch 32, the spacer 1 can be more easily and reliably fixed to the vertebral arch 120. Further, the thread 302 can be prevented from being displaced or loosened during and after the operation, and the fixed state of the spacer 1 can be reliably maintained.

  Further, the notch 32 may be provided at any position on the flange 31, but is preferably located near the opening of the first through hole 51. Thereby, the distance of the notch 32 and the 1st through-hole 51 becomes short, and the shift | offset | difference and loosening of the thread | yarn 301 can be prevented more effectively. Furthermore, since the part which the thread | yarn 301 and the cutting | disconnection edge part 120a, 120b contact directly decreases, the bone fusion between the side surface 12 and the cutting | disconnection edge part 120a, 120b can be made stronger.

  Further, the opening of the first through hole 51, the opening of the second through hole 52, and the notch 32 are aligned in a straight line when the two side surfaces 12 are viewed from the front as in the present embodiment. It is preferable. Thereby, the spinous process 130 and the spacer 1 can be fixed without dispersing the fixing force by the yarns 301 and 302, so that the yarns 301 and 302 are reliably prevented from being displaced or loosened. be able to.

  The spacer 1 has a rounded corner at the end of the flange 31 (R is attached). With this configuration, there is an advantage that it is possible to prevent the surrounding tissue from being damaged when the spacer 1 is inserted into the gap 150.

  In such a spacer 1 (spacer main body 2), the dimensions of each part are set as follows.

The length in the front-rear direction (L _{1 in} FIG. 1) of the spacer 1 (spacer main body 2) is preferably about 5 to 12 mm, and more preferably about 5 to 7 mm.

  Further, the length in the vertical direction (H in FIG. 1) of the spacer 1 (spacer body 2) is preferably about 5 to 12 mm, and more preferably about 5 to 7 mm.

Moreover, it is preferable that the length (W1 in FIG. ₁ ) of the left-right direction of the spacer main body 2 is about 6-27 mm, and it is more preferable that it is about 13-25 mm.

Also, the left-right direction of the length of the spacer main body 2 (in FIG. 1 _{W 2)} is preferably about 4～21Mm, more preferably about 6～18Mm.

Further, the average inner diameter (r _{1 in} FIG. ₁ ) of the first through-hole 51 is preferably about Φ0.3 to Φ3 mm, and more preferably about Φ0.7 to Φ1.2 mm.

The average inner diameter (r _{2 in} FIG. 1) of the second through-hole 52 is preferably about Φ0.5 to Φ5 mm, and more preferably about Φ1.0 to Φ2.0 mm.

Further, the separation distance (L _{2 in} FIG. 1) between the notch 32 and the first through hole 51 is preferably about 0.1 to 2 mm, and more preferably about 0.3 to 1 mm.

  By setting the dimensions of each part in the spacer 1 within the above-described range, the spinal canal 140 can be enlarged to an appropriate size, and the machine excellent in the spacer 1 while preventing its thickness from increasing. The mechanical strength can be imparted more reliably.

  In addition, by making the through holes 51 and 52 have a relatively small inner diameter as described above, the invasion of osteoblasts into the through holes 51 and 52 is promoted, and osteogenesis occurs in the through holes 51 and 52. There is also an advantage that the fusion between the spacer 1 and the cut ends 120a and 120b can be further promoted.

  Such a spacer 1 is preferably made of a ceramic material as a main material. Since the ceramic material is excellent in workability, in the manufacturing process of the spacer 1, it is easy to adjust its shape, size, etc. by cutting using a lathe, a drill or the like.

  Examples of the ceramic material include various materials, and bioceramics such as alumina, zirconia, and calcium phosphate compounds are particularly preferable. Among these, a calcium phosphate compound is particularly preferable as a constituent material of the spacer 1 because it has excellent biocompatibility.

  Examples of the calcium phosphate compound include apatites such as hydroxyapatite, fluorapatite, and carbonate apatite, dicalcium phosphate, tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, and the like. Species or a combination of two or more can be used. Of these calcium phosphate compounds, those having a Ca / P ratio of 1.0 to 2.0 are preferably used.

  Of such calcium phosphate compounds, hydroxyapatite is more preferable. Hydroxyapatite has an excellent biocompatibility because it has the same structure as the mineral main component of bone. Further, it is possible to expect the fusion between the spacer 1 itself and the cut ends 120a and 120b.

  The spacer 1 may be a dense body or a porous body, but is preferably a porous body. By constituting the spacer 1 with a porous body, it is possible to invade osteoblasts into the spacer 1, and osteogenesis can be performed in the spacer 1. In particular, the spacer 1 is mainly composed of hydroxyapatite. In this case, it is possible to reliably expect the fusion between the spacer 1 itself and the cut ends 120a and 120b and the fusion between the spacer 1 itself and the spinous process 130.

  In the case of a porous body, the porosity is preferably about 0 to 90%, more preferably about 15 to 60%. Thereby, while preventing the mechanical strength of the spacer (porous body) 1 from being lowered, it is possible to allow osteoblasts to enter the spacer 1 more smoothly and to promote osteogenesis in the spacer 1. It becomes. As a result, the bone fusion between the cut ends 120a and 120b and the side surface 12 can be caused more reliably and early.

As a constituent material of the spacer 1, in addition to the above ceramic material, a composite material of the ceramic material and a metal material having a low biological harm such as titanium can be used.
Such a spacer 1 can be manufactured as follows, for example.

  In the following, a case where the spacer 1 made of a ceramic material is manufactured will be described as an example.

[A] First, a molded body having a shape corresponding to the shape of the target spacer 1 is manufactured.
This molded body is, for example, I: a method in which a slurry containing ceramic raw material powder is filled in a predetermined mold and molded, II: a method in which solid content is unevenly distributed to the slurry by precipitation or centrifugation, III : Slurry is put in a predetermined mold and dehydrated to leave the solid content in the mold. IV: Compression molding method (in the case of powder, compacting) V: Ceramic raw material powder and water paste It can be produced by various methods such as mixing, putting it in a mold and drying it.

  The slurry may contain secondary particles granulated in advance by a spray drying method or the like as a ceramic raw material powder.

  Moreover, the porosity of the spacer 1 obtained can be adjusted by adjusting whether or not a binder agent is added to the slurry, the amount of addition when added, the content of bubbles in the slurry, and the like.

  The obtained molded body is dried by, for example, natural drying, hot air drying, freeze drying, vacuum drying, or the like.

  In addition, the dimension of a molded object is set in consideration of the shrinkage | contraction in baking of a post process with respect to the dimension of the spacer 1. FIG.

[B] Next, for example, through holes 51 and through holes 52 are formed in the formed body by machining such as cutting, cutting, grinding, and polishing.
In addition, since the hardness of the molded body is relatively low, machining by machining is easy.

  [C] Next, the molded body thus obtained is fired in, for example, a furnace. Thereby, the molded body is densified and sintered, and the spacer 1 is obtained.

Second Embodiment
Next, a second embodiment of the spacer of the present invention will be described.

  FIG. 7 is a diagram ((a) front view, (b) plan view, (c) side view) showing a second embodiment of the spacer of the present invention.

  Hereinafter, the spacer 1 of the second embodiment will be described focusing on the differences from the spacer 1 of the first embodiment, and the description of the same matters will be omitted.

  The spacer 1 shown in FIG. 7 is the same as the spacer 1 shown in FIG. 1 except that the configuration of the flange 31 is different.

  That is, in the spacer 1 of the second embodiment, the flange 31 includes a hole 34 instead of the notch 32.

  The effect similar to the said 1st Embodiment is acquired also by the spacer 1 of such 2nd Embodiment.

That is, by inserting the thread 301 into the hole 34 and locking it, the spinous process 130 can be fixed to the spacer 1 more easily and reliably. Further, it is possible to prevent the thread 301 from being displaced or loosened during and after the operation, and the fixed state of the spinous process 130 can be reliably maintained. Further, by inserting and locking the thread 302 into the hole 34, the spacer 1 can be more easily and reliably fixed to the vertebral arch 120. Further, the thread 302 can be prevented from being displaced or loosened during and after the operation, and the fixed state of the spacer 1 can be reliably maintained.
In addition, the dimension of each part is the same as that of the spacer 1 of the said 1st Embodiment.

  As mentioned above, although the spacer of this invention was demonstrated based on embodiment of illustration, this invention is not limited to this.

  For example, in the spacer of the present invention, each component can be replaced with any component that can exhibit the same function, or any component can be added.

  For example, in the present invention, any two or more configurations shown in the first and second embodiments may be combined. Specifically, in the spacer 1, one of the flanges 31 may include a notch 32 and the other may include a hole 34.

  Moreover, in the spacer of the said embodiment, although all showed about the structure provided with the flange which functions as an engaging part, in the spacer of this invention, an engaging part may be abbreviate | omitted, and the position is also in the case of providing. For example, the central portion of the side surface 12 may be provided.

  In addition, in the spacers of the above-described embodiments, the shape of the insertion portion when viewed from the top is substantially trapezoidal. However, the spacer according to the present invention has an overall shape of the insertion portion such as a columnar shape or a rectangular column shape. It may be a columnar shape.

It is a figure which shows 1st Embodiment of the spacer of this invention. It is a figure for explaining the midline longitudinal split type laminoplasty step by step. It is a figure for explaining the midline longitudinal split type laminoplasty step by step. It is a figure for explaining the midline longitudinal split type laminoplasty step by step. It is a figure for explaining the midline longitudinal split type laminoplasty step by step. It is a figure for explaining the midline longitudinal split type laminoplasty step by step. It is a figure which shows 2nd Embodiment of the spacer of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spacer 11 Front surface 12 Side surface 13 Rear surface 14 Upper surface 15 Lower surface 2 Spacer main body 3 Engagement part 31 Flange 32 Notch 34 Hole 51 First through-hole 52 Second through-hole 100 Vertebral 110 Vertebral body 120 Lumbar 120a, 120b Cutting End portion 121a, 121b Groove 122a, 122b Hinge portion 123a, 123b Through hole 130 Spinous process 131 Cutting line 132 Cutting surface 133 Through hole 140 Spinal canal 150 Gap 160 Enlarged vertebra 200 Midline surface 301, 302 Thread

Claims (15)

Used to dissect the spinous process from the vertebral arch, and to cut the vertebral arch at the part where the spinous process has been separated and inserted into the gap formed by cutting the vertebral arch to expand the spinal canal A spacer,
Two vertebral abutment surfaces with which both ends of the cut portion of the vertebral abutment are in contact with each other, a spinous process attachment surface for attaching the separated spinous process, and a penetration between the two vertebral abutment surfaces to the average inner diameter and a first through hole and the average inner diameter of said average inner diameter φ0.5~5mm greater than the first through-hole the second through hole of Fai0.3～3Mm,
A linear first fixing member is inserted into the first through-hole to fix the spinous process to the spinous process attachment surface, and a linear second fixing member to the second through-hole. The spacer is configured to be inserted and fixed in the gap in a state in which the two vertebral abutment surfaces are in contact with both ends of the portion where the vertebral arch is cut.   The spacer according to claim 1, wherein the spacer is inserted into the gap formed between the both ends so that the spinous process attachment surface faces the outside of the vertebral arch.   The spacer according to claim 1, wherein an area of the spinous process attachment surface is larger than an area of a cut surface of the spinous process.   2. The end portions of the two arch contact surfaces located outside the vertebral arch and the both end portions of the spinous process attachment surface are adjacent to each other with the spacer inserted in the gap. 4. The spacer according to any one of 3.   The spacer according to any one of claims 1 to 4, wherein the first through hole is located outside the vertebral arch with respect to the second through hole in a state where the spacer is inserted into the gap.   6. The device according to claim 1, wherein the first through hole and the second through hole are arranged side by side from the patient's back to the stomach while the spacer is inserted into the gap. The spacer according to crab.   The spacer according to any one of claims 1 to 6, wherein each of the two vertebral abutment surfaces is provided with an engaging part capable of engaging with both ends of a portion where the vertebral arch is cut.   The spacer according to claim 7, wherein the engaging portion is provided so as to protrude from the arch contact surface.   The spacer according to claim 8, wherein the engaging portion is provided so as to constitute one flat surface continuous with the spinous process attachment surface.   The spacer according to claim 7, wherein the engaging portion includes a notch or a hole into which at least one of the first fixing member and the second fixing member is inserted.   The spacer according to claim 10, wherein the notch or the hole is located in the vicinity of an opening of the first through hole.   The opening of the first through hole, the opening of the second through hole, and the notch or the hole are aligned in a straight line when the two contact surfaces are viewed from the front. Item 12. The spacer according to Item 10 or 11.   The spacer according to claim 1, wherein the spacer is made of a ceramic material.   The spacer according to claim 13, wherein the ceramic material is made of a calcium phosphate compound.   The spacer according to claim 13 or 14, wherein the ceramic has a porosity of 0 to 90%.

Images