JP5568787B2 - Implants used in canine cervical ventral decompression - Google Patents

Description

The present invention relates to an implant for use in cervical ventral decompression that is used as a surgical treatment for canine cervical intervertebral disc protrusion, prolapse.

  Canine cervical disc protrusion / prolapse is mainly due to cervical disc disease that occurs in cartilage dystrophic dogs such as dachshund and beagle and small dogs, and Doberman and Great called Wobbler syndrome. -It may be due to a spinal cord injury disease that occurs in the lower cervical spine region of large dog breeds such as Dane.

  In cervical disc protrusion / deviation, degenerated nucleus pulposus material flows into the spinal canal due to complete tearing of the dorsal side of the annulus (deviation), or the dorsal side of the annulus bulges into a dome shape due to degeneration of the intervertebral disc ( Protrusion) compresses the spinal nerve and causes spinal cord injury.

  Therefore, in the treatment of cervical disc protrusion / prolapse, it is important to surgically remove the disc material that presses the spinal nerve and decompress the spinal cord. For this reason, dorsal decompression (for example, dorsal decompression) Surgical treatment methods such as lateral laminectomy and ventral decompression (for example, cervical ventral decompression) have been proposed (see, for example, Non-Patent Document 1).

  In these decompression procedures, when decompression is performed alone, the intervertebral disc space is left by the removal of the intervertebral disc material, thereby increasing instability between the vertebrae after the operation and new spinal cord disorders. There is a risk of complications such as

  Therefore, at the same time as the decompression treatment, a distraction fixation treatment for fixing and stabilizing the intervertebral portion after the disc material extraction is performed. As this distraction fixation treatment, for example, a method in which pins are inserted into vertebrae before and after the intervertebral vertebrae and the pins are joined together by bone cement, or as an implant between the vertebrae that have been interstitial. A method of fixing with a pin and bone cement after inserting cancellous bone, methyl methacrylate bone cement or stainless steel washer is known (for example, see Non-Patent Document 2).

However, the load applied to the spinal cord of the dog is larger than expected, and in these conventional distraction fixation procedures, after the operation, the large load applied to the spinal cord gradually causes loosening of the fixed part, resulting in unstable intervertebral part. There is a risk of complications that are difficult to treat, such as collapse of the vertebrae in extreme cases.
In addition, the conventional intervertebral stabilization treatment requires a long time, and the entire operation time including decompression is increased, resulting in a large surgical invasion.

Yasuharu Izumisawa, 2 others, “Neck ventral decompression”, Interzoo, Inc., July 1, 1999, Volume 3, Issue 4, p. 18-p. 24 Yasushi Hara, “Wobler Syndrome”, Interzoo Co., Ltd., September 1, 2005, Vol. 9, No. 5, p. 33-p. 48

  The object of the present invention is to securely fix and stabilize the intervertebral part after the removal of the disc material in the cervical ventral decompression of the dog, thereby preventing postoperative complications and shortening the operation time. It is to reduce the surgical invasion.

In order to solve the above problems, according to the present invention, a midline of the neck and abdomen of a dog having cervical disc protrusion / deviation is incised over a predetermined length centering on the target vertebra, and the intervertebral space is sandwiched. A pair of vertebral bodies located at the front and back are exposed, and a ventral slot having a predetermined width and length extending in the body axis direction across the vertebrae is formed in the pair of vertebral bodies, and the ventral slot and An implant to be used in a ventral decompression of a cervix of a dog, which is subjected to a distraction fixation process for extracting a disc material from the intervertebral disc, fixing the pair of intervertebral segments, and suturing the incision, and has been bioactivated. The ventral slot is made of a single piece of titanium or titanium alloy having a cross-shaped cross section having a certain length, and is designed based on a CT image obtained by photographing the affected area before surgery for each dog to be operated on. Interior space A longitudinal portion of corresponding shape, extending across the central portion of the longitudinal portion, and a lateral portion having a shape corresponding to the internal space of the intervertebral gap, during the distraction fixed procedure, the disc As a result of the extraction of the substance, the cross-shaped longitudinal hole formed from the ventral slot and the intervertebral space extending from the ventral side toward the spinal cord has one end of the cruciform facing the spinal cord, An implant is provided that is driven so that the end face is exposed to the ventral side of the neck .

In this case, the bioactivation process includes, for example, sequentially executing alkali treatment and heat treatment, or sequentially executing acid treatment and heat treatment.

  According to the present invention, in the cervical ventral decompression of a dog, from the ventral side formed from ventral slots and intervertebral spaces that extend along the body axis across the target vertebra after the removal of the intervertebral disc material An implant with a cruciform cross section adapted to the longitudinal hole is driven into the longitudinal hole extending toward the spinal cord, and the intervertebral portion is fixed, so that the intervertebral disc defect is filled with the implant and the vertebral bodies before and after the intervertebral The cross-shaped implants are joined without being displaced in the body axis direction and the direction perpendicular thereto. As a result, even if a large load is applied to the post-operative intervertebral portion, the intervertebral portion is securely fixed, and postoperative complications are prevented from occurring.

Further, according to the present invention, the distraction fixation treatment is completed simply by driving the implant into the longitudinal hole of the cross-shaped cross section left after the disc material is removed, so that the operation time is significantly shortened compared to the conventional method, and the surgical invasion Becomes smaller.
Furthermore, if a bioactively treated implant is used, this implant is excellent in apatite-forming ability, so that it is firmly bonded to adjacent vertebral bodies (living bones) before and after that, so that the disc defect portion is It is repaired quickly and the intervertebral part is securely fixed.

1 is a flow diagram of a dog's cervical ventral decompression according to the present invention. It is a figure explaining a series of procedures of the cervical ventral decompression of a dog according to the present invention. It is a top view which shows the ventral slot formed in the vertebral body before and behind the intervertebral. It is a figure which shows the shape of an implant, A is the perspective view seen from the back side, B is the perspective view seen from the front side, C is a back view. It is a side view which shows the state by which the implant was driven into the intervertebral part.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a flow diagram of a dog's cervical ventral decompression according to the present invention, and FIG. 2 is a diagram illustrating a series of procedures for a dog's cervical ventral decompression according to the present invention. 2A to 2G, the left side of the drawing is the head side and the right side is the caudal side.
In addition, the cervical ventral decompression of the dog according to the present invention has the same configuration as the conventional cervical ventral decompression of the dog except for the configuration of the distraction fixation treatment for fixing the intervertebral portion after the removal of the intervertebral material. Yes.

  With reference to FIG. 1 and FIG. 2, according to the method of the present invention, first, a dog having cervical disc protrusion / prolapse is anesthetized, and as shown in FIG. While lying on the bed 1 in a supine position, the forelimbs 3a, 3b are pulled to the caudal side and held so that there is no left and right rolling during the operation (S1 in FIG. 1). At that time, a mat 4 is laid on the neck 3 c to extend the neck 3 c, and the lower jaw is fixed to the surgical bed 1 with the adhesive tape 5.

Next, as shown in FIG. 2B, the midline of the dog's neck and abdomen is incised subcutaneously over a predetermined length (5 to 10 cm) with the target intervertebral center (S2 in FIG. 1). This subcutaneous incision is advanced until a pair of left and right sternohyoid muscles 6 and sternum mastoid muscle 7 appear.
Then, as shown in FIG. 2C, the fascia at the center of the sternohyoid muscle 6 and the sternomastomas 7 is incised and separated to expose the trachea 8 (S3 in FIG. 1), and as shown in FIG. 2D. Then, the retractor 10 is inserted in the center of the sternohyoid muscle 6 and the sternomastomas 7 and spreads left and right (S4 in FIG. 1). At this time, on both sides of the trachea 8, there is a carotid sheath 12 to which the recurrent nerve is attached on the dorsal side, and the esophagus 9 is located on the dorsal side. Then, as shown in FIG. 2E, the trachea 8 and the right carotid artery sheath 13 are bluntly separated, and the trachea 8 and the esophagus 9 are displaced by the rake retractor 14 or the like (S5 in FIG. 1).

Next, as shown in FIG. 2F, after palpating the center of the cervical long muscle to palpate the abdominal nodule 15 of the cervical vertebra and confirming the target vertebra, the tendon of the cervical long muscle immediately after the anterior cervical abdominal nodule A slight transverse incision is made, and the cervical long muscle fibers adhering to the cervical spine are peeled off using a sharply curved Metzenbaum scissors 16 or the like (S6 in FIG. 1).
Thereafter, as shown in FIG. 2G, the tendon origin of the cervical longus 11 attached to the abdominal nodule 17 is bluntly separated from the cervical longus 11 to the left and right, and a Gerpy retractor is placed between them to open (see FIG. 2G). 1 S7). In this case, the vertebral bodies 20 and 21 before and after the intervertebral disc 19 are widely exposed to form a ventral slot.

Then, the cranial cervical abdominal nodule is excised with Ronjur, the ventral annulus of the intervertebral disc 19 is cut off with a surgical knife, and further, the round bar is used to extend to the front and rear vertebral bodies 20, 21 across the intervertebral space. A ventral slot 22 having a rectangular cross section is formed (S8 in FIG. 1). This situation is shown in FIG.
In this case, the center of the ventral slot 22 is basically formed in the middle of the vertebral bodies 20 and 21 and slightly on the cranial side of the intervertebral space. This is because the cervical vertebra is tilted from the ventral side toward the dorsal side. Further, in order to avoid damage to the vertebral sinus passing through the ventral side of the spinal canal or the ventral sinus, the ventral slot 22 has a width and a length corresponding to those of the vertebral bodies 20 and 21, respectively. Do not exceed 1/3.

  After the formation of the ventral slot 22, the dorsal annulus and, if necessary, the dorsal longitudinal ligament are excised using an ophthalmic scissors or a surgical knife. Thereafter, the disc material is extracted by pulling the disc material with a nerve root elevator or the like, finely dividing it, sucking the disc material with a small-diameter flanger suction tube, or removing the disc material with a small forceps or the like (Fig. 1 S9).

  After removing the disc material, distraction fixation is performed to fix the intervertebral part. According to the present invention, this distraction fixation procedure results in a cross-shaped longitudinal hole 23 extending from the ventral side toward the spinal cord, formed from the ventral slot 22 and the intervertebral space 19 'as a result of the extraction of the disc material. The implant has a cross-shaped cross section and is shaped to fit the vertical hole 23 (S10 in FIG. 1).

4 is a view showing the shape of the implant, FIG. 4A is a perspective view seen from the back side, FIG. 4B is a perspective view seen from the front side, and FIG. 4C is a back view.
Referring to FIG. 4, the implant 24 is made of a single body made of titanium or a titanium alloy having a certain cross-sectional shape, which has been subjected to bioactivity, and has a shape corresponding to the inner space of the ventral slot 22. It has a longitudinal portion 25 and a transverse portion 26 shaped to correspond to the internal space of the intervertebral space 19 ′ extending across the central portion of the longitudinal portion 25.

  The implant may be a custom-made implant designed and manufactured based on a CT image obtained by imaging the affected area before the operation for each dog to be operated, for example, designed in advance for each dog type and physique The produced general-purpose thing may be used. In the latter case, two or more implants of different sizes are prepared in advance, and the implants are taken in and out of the longitudinal hole one by one, and the suitability of the implant with respect to the longitudinal hole is checked by a CT image each time. It is preferable to determine an implant that best fits and to drive the determined implant into the longitudinal hole.

One method of bioactivity treatment includes a method of sequentially executing alkali treatment and heat treatment. According to this method, for example, a pure titanium implant having the shape shown in FIG. 4 is washed with 2-propanol and ultrapure water, then immersed in a container containing a 5M aqueous sodium hydroxide solution, and placed in an oil bath at 60 ° C. Hold it for 24 hours while shaking at 120 strokes / minute. The implant is washed with ultrapure water and then dried at 40 ° C. Next, the implant is immersed in a 0.5 mM hydrochloric acid aqueous solution for 24 hours, washed with ultrapure water, and dried at 40 ° C. Further, the implant is placed in a heating furnace, heated at a rate of 5 ° C./min in the atmosphere, held at 600 ° C. for 1 hour, then naturally cooled in the heating furnace, and the bioactive treatment is completed.
In this example, in order to further examine the effectiveness of the bioactive treatment, the implant treated by this method was taken out after being immersed in a simulated body fluid at 36.5 ° C. for 1 day, and the surface of the implant was removed using a scanning electron microscope. By observing, it was confirmed that the implant surface was covered with apatite particles.

In addition, as another method of bioactivity treatment, a method of sequentially executing acid treatment and heat treatment can be mentioned. According to this method, a pure titanium implant having the shape shown in FIG. 4 is washed with 2-propanol and ultrapure water, and then a one-to-one ratio of 66.3% sulfuric acid and 10.6% hydrochloric acid is used. It is immersed in a container containing the solution mixed at a ratio, put in an oil bath at 70 ° C., and held for 1 hour while vibrating at 120 strokes / minute. The implant is washed with ultrapure water and then dried at 40 ° C. Next, the implant is placed in a heating furnace, heated at a rate of 5 ° C./min in the atmosphere, held at 600 ° C. for 1 hour, then naturally cooled in the heating furnace, and the bioactive treatment is completed.
In this example, in order to further examine the effectiveness of the bioactive treatment, the implant treated by this method was taken out after being immersed in a simulated body fluid at 36.5 ° C. for 1 day, and the surface of the implant was removed using a scanning electron microscope. By observing, it was confirmed that the implant surface was covered with apatite particles.

As shown in FIG. 5, the implant 24 has an intervertebral surface so that one cross-shaped end surface (front surface) 27a faces the spinal cord and the other cross-shaped end surface (back surface) 27b is exposed to the ventral side of the neck. It is driven into a vertical hole 23 having a cross-shaped cross section provided in the section. In this case, one through-hole for screw is provided in the implant 24 in advance, the implant 24 is driven into the longitudinal hole 23, and then the screw is inserted into the vertebral body 21 on the rear side through this through-hole. May be fixed to the vertebral body 21 on the rear side.
After the driving of the implant 24 is completed, the incision is sutured (S11 in FIG. 1).

  In the cervical ventral decompression of the dog according to the present invention, after the removal of the intervertebral disc material, the ventral side to the spinal cord is formed from ventral slots and intervertebral spaces that extend along the body axis across the target vertebra. An implant having a cruciform cross section adapted to the longitudinal hole is driven into the longitudinal hole extending toward the longitudinal hole, and the intervertebral portion is fixed. Therefore, the intervertebral disc defect is filled with the implant, and the anteroposterior vertebral bodies are joined by the cruciform cross-section implant without shifting in the body axis direction and the direction orthogonal thereto, so that Even if a large load is applied to the part, the intervertebral part is securely fixed, and postoperative complications are prevented.

Also, according to the cervical ventral decompression of the present invention, the distraction fixation treatment is completed simply by driving the implant into the longitudinal hole of the cruciform cross section left after the removal of the intervertebral disc material. The operation time is greatly shortened and the surgical invasion is also reduced.
In addition, the implants used are bioactive and have excellent apatite-forming ability, so they are firmly bonded to the adjacent vertebral bodies (living bones) in the front and back, thereby quickly repairing the disc defect. And the intervertebral part is securely fixed.

DESCRIPTION OF SYMBOLS 1 Surgical bed 2 Dog 3a, 3b Forelimb 3c Neck part 4 Mat 5 Adhesive tape 6 Sternohyoid muscle 7 Sternomastoid muscle 8 Trachea 10 Esophageal tract 10 Retractor 11 Neck long muscle 12 Carotid sheath 13 Right carotid sheath 14 Rey tractor 15 Abdominal nodule 16 Metzenbaum scissors 17 Abdominal nodule 19 Intervertebral disc 19 'Intervertebral space 20, 21 Vertebral body 22 Ventral slot 23 Vertical hole 24 Implant 25 Longitudinal portion 26 Lateral portion 27a Cross-shaped end face (front surface)
27b Cross-shaped end face (back)

Claims (2)

The midline of the cervical abdomen of a dog with cervical disc protrusion / prolapse is incised over a predetermined length centering on the target vertebra, exposing a pair of vertebral bodies located at the front and back across the intervertebral space, Forming a ventral slot having a predetermined width and length extending in the body axis direction across the intervertebral space in the pair of vertebral bodies, and extracting disc material from the ventral slot and the intervertebral space; An implant for use in a ventral decompression of the neck of a dog that performs a distraction fixation procedure to fix the intervertebral space and sutures the incision ;
It is made of a single body made of titanium or titanium alloy with a cross-shaped cross section that has a certain length, and is designed based on a CT image obtained by imaging the affected area before surgery for each dog to be operated. A longitudinal portion having a shape corresponding to the internal space of the ventral slot, and a lateral portion having a shape corresponding to the internal space of the intervertebral space extending across the central portion of the longitudinal portion,
During the distracting and fixing procedure , as a result of the extraction of the intervertebral disc material, a cross-shaped end hole formed from the ventral slot and the intervertebral space and extending from the ventral side toward the spinal cord has a cross-shaped end surface. An implant characterized by being driven so as to face the spinal cord and to expose the other end face of the cross shape on the ventral side of the neck . The implant according to claim 1, wherein the biological activation treatment includes sequentially performing alkali treatment and heat treatment, or sequentially performing acid treatment and heat treatment.

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