JP2010046463A - Interspinous spacer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent ingression into a spine and to reduce surgical invasion in an interspinal spacer instrument which is used in surgical treatment for lumbar spinal canal stenosis. <P>SOLUTION: The instrument includes: a bag which has an accordion structure based on a variable molding material; and an insertion auxiliary portion based on a hard material surrounding its lateral face. When a bone cement is injected into the bag, it stretches in a craniocaudal direction, broadens an interspinal space, and forms a contacting face fitting to the form of the spine. Thus, stress can be dispersed to prevent ingression into a bone. Because of the accordion structure of the bag, it is thin in insertion, so that insertion is not impaired. In addition, the insertion auxiliary portion allows insertion by deploy of only one side of the interspinal space, reduces invasion, and prevents expansion to another side of the bag in injection. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an interspinous process spacer device intended to suppress the lordosis between the vertebrae by inserting it between the spinous processes of the lumbar spine for lumbar spinal canal stenosis.

  Lumbar spinal canal stenosis is a disease characterized by intermittent claudication in which the symptoms of lower limbs worsen during standing or walking and improve in a sitting or lumbar flexion position. This is because the spinal canal narrows due to enlargement of the facet joint, thickening of the yellow ligament, swelling of the intervertebral disc, etc. It is considered as a disease state that exacerbation of crystallization.

  There are already devices that are inserted between spinous processes for the purpose of suppressing the lumbar lordosis and suppressing the increase in the thickness of the yellow ligament and preventing the onset of symptoms even when standing or walking. There are Wallis system (Abbott Spine), X-STOP (Kyphon Inc.), Coflex (Paradigm Spine), DIAM (Meditronic Sofam Danek) and the like.

  Since the instrument inserted between the spinous processes supports a large load with a small area of the cranial and caudal edges of the spinous processes in contact with the instrument, there is a problem that the load on the bone is too large.

  We compared X-STOP images immediately after surgery and one month after surgery, and as a result, the enlargement between the spinous processes obtained by surgery lost a significant percentage after one month. I found out. In other words, it is considered that the spinous processes are biting at the contact portion between the spinous processes and the instrument.

  X-STOP is made of metal, but in the Wallis system, it is made of a flexible material called PEEK (polyetherethertone), which is intended to reduce the impact on the spinous process. DIAM is also made of silicone covered with polyester, and Coflex is also trying to mitigate impacts due to its U-shape. However, since it is flexible, the interspinous process enlargement effect is reduced when a load is applied. Since the spinous process spacer is subjected to a considerable load over a long period of time, even if it is a flexible material, if the surface compatibility is poor, it bites into the bone, and there is also a problem of durability, and the debris generated by wear is inflamed May cause. In addition, if plasticity is lost, the interspinous process enlargement effect is further reduced.

  Furthermore, these have the problem of excising an important tissue called the supraspinatus ligament depending on the material, shape and insertion method.

  Moreover, it is necessary for Wallis system, X-STOP, Coflex, and DIAM to expand on both sides of the spinous process, which is highly invasive and causes postoperative pain.

  Therefore, an object of the present invention is to reduce the biting into the spinous process and reduce the surgical invasion in the interspinous process spacer device for the purpose of suppressing the lordosis between affected vertebrae for lumbar spinal canal stenosis.

  The main structure is composed of a bag portion having a bellows structure made of a deformable material and an insertion assisting portion made of metal or the like. An infusion tube is attached to the bag.

  The insertion assisting portion surrounds the outer periphery of the side surface of the bag portion with respect to the head-to-tail direction, has a pointed structure on the insertion direction side, and can be inserted while expanding a narrow space when inserted between the spinous processes. After the insertion, the bag portion is filled with a curable substance such as polymethyl methacrylate (PMMA) used as a medical bone cement to spread between the spinous processes, and after curing, the shape of the spinous processes It becomes a hard spacer that forms a contact surface that matches the above.

  If the bag is too soft, when a curable substance is injected into the bag, it does not extend to the head and tail, but it swells to the left and right to squeeze the paraspinal muscles, or to pinch the left and right spinous processes. Then, it interferes with the rotational movement. The bag part is made of a material that is not highly flexible, or the thickness of the material is increased to reduce the flexibility, but it must be stretchable in the head-to-tail direction. I made it. Thereby, the variable formability is small in the left and right abdominal back direction, the variable formability can be increased in the head-to-tail direction, and the pressure resistance can be increased. Further, the insertion assisting portion surrounding the side surface of the bag portion suppresses lateral spread.

  In the surgical procedure, only one of the left and right sides of the interspinous process is expanded, the interspinous ligament is perforated from the side, and the curettage is moderately scraped. The supraspinatus ligament preserves. After the contents of the bag portion of the device of the present invention are sucked from the tube and squeezed, the device of the present invention is inserted between the spinous processes from the side from the deployment side. After insertion, after having the patient bend the trunk, PMMA is injected into the bag part from the tube and pressurized until the supraspinatus ligament is stretched. When the PMMA is cured, cut off the tube.

  When the bag portion is squeezed and thinned due to the bellows structure, insertion does not hinder insertion, and the insertion assisting portion facilitates insertion into a narrow space. At the time of PMMA injection, it expands in the cranial and caudal direction and opens between the spinous processes. Due to the deformability of the bag portion, a contact surface that matches the shape of the contact surface with the spinous process is formed, so that stress can be dispersed and biting into the bone can be suppressed.

  This is possible by deploying only one side of the interspinous process and is less invasive. Also, the supraspinatus ligament can be preserved.

  By controlling how the bag portion swells at the time of injection, the bag portion can be effectively extended in the direction of expanding between the spinous processes, and the shape of the contact surface can be adapted to the bone shape.

  Embodiment 1 of this invention is demonstrated based on FIGS. As shown in FIG. 1, the main structure is composed of a bag portion 1 and an insertion assisting portion 2 which are made of a deformable material and have a bellows structure. The insertion assisting portion 2 is made of a metal such as titanium, surrounds the outer periphery of the side surface of the bag portion 1, and is partially bonded to the bag portion 1. Details of the bag portion 1 will be described with reference to FIG. The bag portion is made of a deformable material such as heat-resistant silicone, and its head side surface 3 and tail side surface 4 form a flat surface or a slightly convex surface, and have a bellows structure on the side surface 5 with respect to the head-tail direction. A tube 6 protrudes from the left edge of the back side surface. Bone cement or the like can be injected from the tube 6 and is made of a flexible material that can be clamped. Details of the insertion assisting portion 2 shown in FIG. 1 will be described with reference to FIG. The right surface of the insertion assisting portion has an outwardly convex pointed structure 7. The left side of the insertion assisting portion has a grasped structure 8 and can be grasped by the insertion instrument 9. Other parts are plate-shaped.

  As a surgical procedure, only one side of the spinous process is expanded, the supraspinatric ligament is preserved, the interspinous ligament is punctured, and a part is excised. After sucking air from the tube 6 of the instrument of the present invention to minimize the bag portion 1, the tube 6 is clamped. The interspinous expander 10 shown in FIG. 5 is inserted on the back side of the interspinous process to widen the interspinous space. It pushes between the spinous processes from the pointed structure 7 of the insertion assisting part 2, and is installed so that the head side surface 3 and the caudal side surface 4 of the bag part 2 are in contact with the spinous processes. By injecting bone cement from the tube 6, the bag portion 1 expands its bellows structure so that the head side surface 3 and the tail side surface 4 expand the upper and lower spinous processes and fit the shape and angle of the contact surface. Deform. While confirming the tension of the supraspinatus ligament, after appropriately injecting bone cement, the tube 6 is clamped and waits until the bone cement is hardened. When the bone cement has hardened, the tube 6 is cut.

  A second embodiment of the present invention will be described with reference to FIG. Although the main structure is the same as that of the first embodiment, the insertion assisting portion penetrates the inside of the inner cylinder of the bag portion 11 so that the bridge portion 12 penetrates left and right, and the pointed structure 13 and the grasped structure 14 on the left and right sides of the bag portion. It is joined. The pointed structure 13 and the grasped structure 14 have hole structures 15 and 16, respectively, through which the artificial ligament can be passed. The artificial ligament is fastened by turning to the adjacent spinous process on the caudal side.

It is a perspective view of Embodiment 1 of the present invention. It is a perspective view of the bag part of Embodiment 1 of the present invention. It is a perspective view of the insertion auxiliary | assistant part of Embodiment 1 of this invention. It is a perspective view of the instrument for insertion of Embodiment 1 of the present invention. It is a perspective view of the interspinous expander of Embodiment 1 of the present invention. It is a side view of Embodiment 2 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bag part 2 Insertion assistance part 3 Bag part head side surface 4 Bag part tail side surface 5 Bag part side surface 6 Tube 7 Insertion assistance part cusp shape structure 8 Insertion assistance part grasping structure 9 Insertion instrument 10 Interspinous expander 11 Bag part 12 Insertion assisting portion bridge portion 13 Insertion assisting portion pointed structure 14 Insertion assisting portion grasped structure 15 Pointed structure portion hole structure 16 Hole grasping structure portion hole structure

Claims (6)

  An instrument that is inserted between the spinous processes and serves as a spacer between the spinous processes, the main structure is composed of a bag part made of deformable material and an insertion assisting part made of a hard material, and the bag part has a side surface in the direction of its head and tail. A device having a bellows-like structure, wherein a part or all of the insertion assisting portion is located near the outside of the side surface of the bag portion with respect to the head-to-tail direction.   2. The interspinous process spacer device according to claim 1, wherein the insertion assisting portion surrounds a side surface of the bag portion with respect to the head-to-tail direction except for the entire circumference or a part thereof.   The interspinous process spacer device according to claim 1, wherein the insertion assisting portion forms a lump structure on the left and right outwards of the bag portion, and penetrates the bag portion or the inner cylindrical structure provided in the bag portion. Is connected to the left and right massive structures.   The interspinous process spacer device according to any one of claims 1 to 3, wherein the right or left side of the insertion assisting part has a pointed structure in which the cross-sectional area decreases toward the outside. Equipment characterized by   The interspinous process spacer device according to any one of claims 1 to 4, wherein an infusion tube for injecting a curable substance such as bone cement is attached to the bag portion.   The interspinous process spacer device according to any one of claims 1 to 5, wherein the insertion assisting portion has a groove structure or a hole structure for inserting a metal plate, a fiber artificial ligament or the like. Instruments.

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