KR20040022602A - Cage for intervertebral body fusion - Google Patents

Abstract

Cages for intervertebral fusion surgery have been disclosed that facilitate intervertebral interbody insertion, prevent movement after insertion, and facilitate surgical procedures. The front part with the central opening is formed to facilitate the fusion of tissues and bones of adjacent vertebral bodies, the left and right sides with a plurality of side openings extending from the anterior part and connected to the central opening to facilitate bone fusion. It is formed on the upper and lower surfaces of the left and right sides, respectively, the upper and lower surfaces formed with one or more threaded protrusions for contact with the vertebral body to prevent movement during intervertebral body insertion, and extend from the left and right sides and face the anterior part, intervertebral interbody insertion. There is provided a cage for intervertebral fusion surgery in which a rear portion formed with one or more fixing pins on the upper or lower surface to prevent movement during vision is integrally formed. It is easy to insert between the vertebral bodies, and after the insertion, it is possible to prevent the departure from outside the intervertebral body and the movement of the front and rear, left and right positions in the intervertebral body, reducing the pain of the patient and smoothly progressing the bone fusion, and ultimately effective treatment is possible.

Description

Cage FOR INTERVERTEBRAL BODY FUSION}

The present invention relates to a cage for use in intervertebral fusion. More specifically, it relates to a cage for intervertebral fusion surgery that can be smoothly fused by inserting between the intervertebral bodies.

The human spine consists of the vertebral body (vertebrae) and fibrocartilaginous discs (disks) between them, which are strengthened by strong ligaments and muscles from the skull to the pelvis, supporting the body and maintaining equilibrium. The intervertebral disc is composed of the annulus fibrosus and the nucleus pulposus, and its shape and size vary depending on the position.

Since there are no blood vessels in the intervertebral discs of adults, the cells in the intervertebral discs are nutrientd by diffusion through the hole in the center of the vertebral epiphyseal plate. In general, lower back pain is caused by rupture or weakening of the lumbar disc.

Therapeutics usually include removal of the sciatica and leg pain by removing the part of the disc that compresses the spinal nerve, posterior fusion after the removal of the damaged disc, intervertebral fusion after the removal of the damaged disc, intervertebral fusion after the removal of the damaged disc. Fusing and the like. In this procedure, the pain caused by the degenerative disc is alleviated by inserting a joint of a solid bone between the vertebral bodies to prevent further disc collapse. Since their bones are difficult to obtain in large quantities, grafts of the same type are usually used a lot, but these implanted bones take longer to grow, and they themselves are not enough to carry a moderate load and have a long fixation time. It has about three times the failure rate than surgery on its own bone.

In order to solve this drawback, Japanese Patent Laid-Open Publication No. Hei 10-234755 has a locking means inserted into the intervertebral bodies to prevent movement between the vertebrae, and cage-like intervertebral bones in which bone fusion between adjacent vertebral bodies can occur smoothly. Artificial prostheses for joint fixation are disclosed.

However, in the case of the present invention, the movement preventing lock means is formed only in part, so that the effect of preventing the left and right movement of the prosthetic intervertebral intervertebral body is insufficient, and because the prosthesis side surface is blocked, it is difficult to smoothly cause fusion.

In order to solve the problems of the above-described invention, Korean Utility Model Registration No. 20-0188509 has an inner passage formed in the insertion direction from the rear end surface in which part or all of the cage is opened, the upper and lower left and right surfaces in the insertion space and A plurality of locking projections are formed on the outer circumferential surface to be brought into contact with each other, and a cylindrical or polygonal pillar-shaped body having a plurality of through holes communicating with the inner passage is connected to the front side of the body, and the entrance front portion first enters the insertion space. In the spine cage, the locking projections are easily inserted into the spine cage by varying the angle of the inclined surface in the front and rear direction of the body, so that they do not fall out once inserted, and the locking grooves or the locking jaws in the left and right directions to some or all of the locking projections. After forming the body into the insertion space by further forming a left and right It discloses a prosthesis for a vertebra in order to prevent the plug from moving.

However, since the plurality of raised projections formed from the surface of the cage are formed uniformly, when inserted into the intervertebral body having a different shape for each individual, it is sufficient to prevent the position fixation of the front and rear of the cage or to prevent the movement to the left and right. There is a disadvantage that can not be. In addition, the shape of the front entrance portion is not easy to insert, there is a problem that increases the surgical surgical time due to difficulty in fixing the final position.

Accordingly, an object of the present invention is to provide a cage for intervertebral fusion surgery, which is easy to intervertebral insertion and prevents the departure or movement of the front and rear, left and right after insertion, and easy surgical operation.

1 is a perspective view of a cage for intervertebral fusion surgery according to a first embodiment of the present invention.

FIG. 2 is a front view of the cage for intervertebral fusion surgery shown in FIG. 1. FIG.

3 is a side view of the cage for intervertebral fusion surgery shown in FIG.

4 is a cross-sectional plan view of the cage for intervertebral fusion surgery shown in FIG.

5 is a perspective view of a cage for intervertebral fusion surgery according to a second embodiment of the present invention.

6 is a perspective view of a cage for intervertebral fusion surgery according to a third embodiment of the present invention.

7A is a plan view of a cage for intervertebral fusion surgery according to a fourth embodiment of the present invention.

7B is a side view of the cage for intervertebral fusion surgery shown in FIG. 7A.

8 is a cross-sectional view of the cage inserted into the intervertebral body according to the present invention.

* Description of the symbols for the main parts of the drawings *

10, 11, 12, 13: cage for intervertebral fusion

20: front 21: central opening

22: female thread 30: left side

31 side opening 35 right side

40: upper surface 41: projection of the thread

42: locking groove 43: locking jaw

45: lower surface 50: rear

51: fixing pin 60: trimming part

70: vertebral body

In order to achieve the above object of the present invention, the present invention has a central opening is formed so that the bone and fusion of the adjacent vertebral body can be easily formed, the front portion that enters for the first time when the intervertebral body is inserted, extending from the anterior portion Facing and formed on each of the left and right sides, the upper and lower surfaces of the left and right sides formed with a plurality of side openings connected to the central opening, one or more threaded projections to prevent movement by contact with the vertebral body during intervertebral insertion Is formed on the upper and lower sides, and extending from the left and right sides facing the front portion, one or more fixing pins for preventing movement during intervertebral interbody insertion, the elongated hexahedral shape intervertebral fusion of the elongated hexahedral shape formed integrally Provide the cage.

Here, the front part is curved to facilitate intervertebral insertion of the cage, and the upper and lower surfaces are preferably formed at an inclination angle of 0 to 8 ° with each other. In addition, the central opening formed in the front portion communicates with the rear portion and forms a female screw inside the central opening, thereby facilitating bone fusion and intervertebral interbody insertion. In addition, in order to prevent the separation between the vertebral bodies and the movement of the vertebrae, the inclination of the front and rear portions of the protrusion of the thread is differently formed, or the locking groove or the locking jaw is formed in some or all of the protrusions of the thread. It is also possible to form a slit in the front part, the rear part, or a part of the left and right sides of the cage so as to absorb the elasticity in the vertical direction between the vertebral bodies. The cage may use a variety of biocompatible materials conventionally used, it is most preferred to use Poly Ether Ether Ketone (PEEK).

According to the present invention, it is easy to insert the intervertebral body, and after the insertion, it is possible to prevent the departure to the outside of the intervertebral body and the movement of the front and rear and left and right positions in the intervertebral body, thereby reducing the pain of the patient and smoothly progressing the bone fusion ultimately effective. Treatment is possible.

Hereinafter, with reference to the accompanying drawings of the present invention will be described in detail.

1 is a perspective view of a cage for intervertebral fusion surgery according to a first embodiment of the present invention, Figure 2 is a front view of the cage for intervertebral fusion surgery shown in FIG.

1 and 2, the intervertebral fusion fusion cage 10 according to an embodiment of the present invention in the form of an elongated hexahedron as a whole, the front portion 20, the left and right sides (30, 35), the upper and lower surfaces ( 40 and 45 and the rear part 50 are integrally formed.

The anterior portion 20 is a portion into which the intervertebral fusion fusion cage is inserted for the first time, and its shape is not in the shape of a quadrangle as in the conventional invention, but in front of the left and right sides 30 and 35 and the upper and lower surfaces 40 and 45. It is formed with a curved outline to the inlet of the central opening part 21 of the edge part 20. Accordingly, when the cage according to the present invention is inserted between the vertebral bodies, the friction with the vertebral bodies is reduced as compared with the conventional invention, so that the insertion can be made more easily.

In addition, the front portion 20 has a central opening 21 is formed to facilitate the bone fusion and tissue of the adjacent vertebral body. Specifically, the central opening 21 formed in the anterior part 20 serves to receive the bone graft and to make the bone fusion with the tissue of the adjacent vertebrae well. Therefore, the central opening 21 is preferably formed in a wide range to withstand the load between the vertebral bodies.

In order to facilitate the fusion between adjacent vertebral bodies, the central opening 21 communicates from the front portion 20 to the rear portion 50, which will be described later, and the side opening portions formed on the left and right side surfaces 30 and 35. It is preferable to also communicate with 31).

Cage for intervertebral fusion surgery according to an embodiment of the present invention includes a left side 30 and a right side 35. The left and right side surfaces 30 and 35 are extended from the front portion 20 to face each other, and a plurality of side opening portions 31 are formed. The side openings 31 formed on the left and right side surfaces 30 and 35 may be deformed as needed in various forms such as circular, elliptical, and rectangular, and communicate with the central opening 21.

The side opening 31 also communicates with the central opening 21 and serves to smoothly fuse the grafted bone fragments present in the central opening 21 to enable rapid and effective treatment.

In addition, the cage for intervertebral fusion includes an upper surface 40 and a lower surface 45. The central openings 21 are formed on the upper and lower surfaces of the left and right side surfaces 30 and 35, respectively, and the central openings 21 communicating from the front part 20 to the rear part 50 are formed without clogging. (21) There are no upper and lower surfaces 40 and 45 above and below.

One or more threaded protrusions 41 are formed on the upper surface 40 or the lower surface 45. The number, shape, and the like of the threaded protrusions 41 may be variously modified. The larger the number of threaded protrusions 41, the greater the movement prevention effect of the intervertebral cages, but may be difficult to process, and by changing the shape of the threaded protrusions 41, the cage is prevented from leaving and moving after intervertebral insertion. Although the effect is large, there may be machining problems, etc., so that the number and shape of the projections 41 of the thread are determined in consideration of this point. In addition, the threaded protrusion 41 may be formed on both the upper surface 40 and the lower surface 45, or may be formed on only one surface of the upper surface 40 or the lower surface 45, if necessary.

The threaded protrusion 41 stimulates the inner wall of the insertion space made of bone tissue during intervertebral interbody insertion, releasing bone fragments and blood, bone growth material, to promote bone fusion, and at the final fixation of the bone tissue and threads of the wall. The projections 41 are engaged with each other to stabilize the fixing position. In other words, this prevents the problem of nerve compression or blood vessel damage when the cage moves after surgery.

Cage for intervertebral fusion surgery according to the present invention includes a rear portion (50). The rear portion 50 extends from the left and right side surfaces 30 and 35 and faces the front portion 20, and one or more fixing pins 51 are formed on the upper or lower surface of the rear portion 50.

Cages for intervertebral fusion surgery according to the present invention are not coupled to the inter-hole discs with threaded grooves, but are used in the form of direct insertion. Therefore, there is a need for an apparatus for fixing the optimal position between the vertebral bodies. In the prior art, since only a screw protrusion was formed, the fixing effect was insufficient, and when the cage stimulated the nerve by deviating from the initial position, the patient brought a great pain and a fatal problem that the therapeutic effect could not be expected. have. However, in the case of the present invention by using a separate fixing pin 51 exerts an excellent effect to prevent the intervertebral fusion between the intervertebral fusion surgery, intervertebral vertebral body, and eventually serves to double the therapeutic effect.

3 is a side view of the cage for intervertebral fusion surgery shown in FIG.

Referring to FIG. 3, the upper and lower surfaces 40 and 45 are formed to be inclined to converge in the direction from the front part 20 to the rear part 50. In the intervertebral fusion procedure, the inclination angle can be changed to facilitate insertion according to the shape of the bone of each patient. Specifically, the line B connecting the ends of the projections 41 of the thread and the cage for intervertebral fusion surgery The angle θ with the lines A and A ′ penetrating the central portion of is preferably formed at an inclination angle of 0 to 8 °, in consideration of the structure of a general human bone.

Since the upper and lower surfaces 40 and 45 are not formed horizontally and are inclined as mentioned above, insertion of the intervertebral bodies is facilitated, and the cage has a shape similar to that of the vertebral disc, thereby maximizing the contact surface with the vertebral plate. It is possible to maximize the bone fusion to achieve the therapeutic effect early.

In addition, it is preferable that the inclinations in the direction of the front portion 20 and the rear portion 50 of the projection 41 of the thread are formed differently. For example, the inclination in the direction of the front part 20 is gentle, and the inclination in the direction of the rear part 50 can be formed rapidly.

When using the intervertebral fusion fusion cage in which the above-described threaded projection is formed, it is relatively easy to insert into the intervertebral body. On the contrary, once it is inserted to the desired position, the departure to the rear part occurs due to the inclination of the sudden protrusion of the thread. It is difficult to help fix the position of the cage. In addition, in the case of using the conventional vertical parallel cage, there may be a case in which more space than necessary when forming the insertion space within the vertebral body spacing may occur, and efficiency may also be reduced in terms of supporting the upper and lower weights. The problem can be solved.

Cage for intervertebral fusion surgery according to an embodiment of the present invention can be manufactured by processing, injection molding using a biocompatible material and harmless to the human body. Generally, carbon, carbon composite material, titanium, titanium composite material, or SUS (steel use stainless) 316L according to Japanese Industrial Standards (JIS) is used as a material having such characteristics, but it is more preferable to use polyether ether ketone. desirable. PEEK is suitable for semiconductor materials and medical materials because it has a high continuous use temperature, excellent chemical resistance, combustion resistance, radiation resistance, and excellent mechanical properties such as tensile and bending strength, toughness, creep resistance, and fatigue properties. The use of PEEK can provide a superior therapeutic effect than that of other materials.

4 is a cross-sectional plan view of the cage for intervertebral fusion surgery shown in FIG.

Referring to FIG. 4, the central opening 21 formed in the front part 20 communicates with the rear part 50. The central opening 21 is not blocked, and communicates from the front part 20 to the rear part 50 so that an empty space is secured and bone fragments are accumulated in the empty space so that bone fusion can occur smoothly.

In addition, a female screw 22 is formed inside the central opening 21. During intervertebral fusion, a drill is used between adjacent spine of the lumbar spine, which forms the insertion space in the dorsal, abdominal, and flank directions of the patient. The insertion space is sufficient to contain a solid cortical bone. It must be wide and deep. Inserted from the front portion 20 of the cage into the formed insertion space, at this time can be easily inserted by inserting the insertion aid tool to the female screw 22.

5 is a perspective view of a cage 11 for intervertebral fusion surgery according to a second embodiment of the present invention.

Referring to FIG. 5, a locking groove 42 or a locking jaw 43 is further formed in the protrusion 41 of the screw thread. The locking groove 42 or the locking jaw 43 may be formed in all or a part of the projections 41 of each thread, the position is also formed in the left groove 30 as shown in FIG. The locking jaw 43 may be formed on the right side 35, but may be modified in various forms, such as taking a structure in which the locking groove 42 and the locking jaw 43 are alternately formed. Can be. The locking jaw 43 and the locking groove 42 serve to prevent movement of the intervertebral fusion fusion cage, in particular, left and right movement together with the fixing pin.

6 is a perspective view of the cage 12 for intervertebral fusion surgery according to the third embodiment of the present invention.

Referring to FIG. 6, a trimming portion 60 is formed in a portion of the front portion 20, the rear portion 50, or the left and right side surfaces 30 and 35 of the cage for intervertebral fusion surgery shown in FIG. 5. The trim 60 may be formed over the left and right side surfaces 30 and 35 and the rear surface as shown in FIG. 6, and is formed over the left and right side surfaces 30 and 35 and the front portion 20 as an application example. Alternatively, it may be formed from a portion of the front portion 20 to a portion of the rear portion 50 via the left side surface 30 or the right side surface 35 of the body. In any case, in order to have elasticity up and down, the upper and lower ends cut by the trimming part 60 should be close to each other by the impact in the vertical direction and then move away again.

Bone remodeling can also be caused by physical forces or microelectrical stimuli, where stress, ie areas of high stress (forces per unit area) and appropriate mechanical stimulation, such as micromotion, occur. Where bones are produced, bones are absorbed at sites with less load (load). According to this bone remodeling mechanism, firm fixation can change bone remodeling and cause osteplysis of the surrounding bone tissue due to the difference in hardness between the bone tissue and the prosthesis. For example, steel is ten times stronger than bone tissue. In the case of fixing with a metal of such a high strength, when a load is applied, normal stress is not transmitted to the bone tissue, and bone absorption occurs locally. Because of this, the structure of the generated bone is weakened, so there is a high risk of fracture. This phenomenon is called stress shielding. In addition, a large difference in strength between the bone and the cage is likely to cause dissociation between the bone tissue and the cage, that is, weakening of the fixation between the bone and the cage.

Therefore, as shown in FIG. 6, by forming the trimming portion 60 on the left and right sides 30 and 35 or the front and rear portions 50 of the intervertebral fusion fusion cage, even if an impact is applied to the vertebra in the vertical direction, the cage is fixed to a certain degree. When the strain is possible, sufficient load and appropriate mechanical stimulus are transferred to the bone pieces filled in the cage, thereby creating an environment favorable for bone remodeling.

In other words, the spine is one of the places where the body is subjected to a large load, and the main form of the load applied is also instantaneous (impact load) and repetitive (fatigue load), so the impact and fatigue performance of the cage structure is very important. In one case, the provision of the trimming part 60 can effectively eliminate the adverse effect of this load on bone growth.

FIG. 7A is a plan view of a cage 13 for intervertebral fusion surgery according to a fourth embodiment of the present invention, and FIG. 7B is a side view of the cage for intervertebral fusion surgery shown in FIG. 7A.

In general, the vertebral bodies that form the human spine are often formed at an angle of inclination rather than being completely parallel to each other. 7A and 7B, the sides of the intervertebral fusion fusion cages 30 and 35 of the intervertebral fusion fusion cage are inclined in the form of convergence toward both ends toward the centers to fit the structures of the above-described vertebral bodies.

In supporting the intervertebral body, a conventional cage may cause more space than necessary in forming the insertion space in the vertebral space, and may also be inefficient in supporting the upper and lower weights. As such, when the shape of the cage side maintains the inclination angle and curved shape similar to the shape of the intervertebral disc, the upper and lower vertebral bodies (bones) and the contact surface can be maximized to increase the treatment effect. In this case, in order to effectively prevent the movement of the vertebral body, the fixing pins 51 may be provided on the front part 20 and the upper and lower surfaces 40 and 45 as well as the rear part 50.

The above-described intervertebral fusion cages exemplify exemplary embodiments of the present invention, and can be applied to various intervertebral fusion fusion cages not mentioned above by combining the structures mentioned in the respective embodiments.

8 is a cross-sectional view of the cage inserted into the intervertebral body according to the present invention. The cages shown in each of the above-mentioned embodiments may be installed alone, or may be installed in pairs.

Referring to FIG. 8, a pair of cages is shown in which the spine is inserted between adjacent vertebral bodies 70. The pair of cages may be cages having the same shape as each other, or cages having different structures. By inserting two cages in pairs according to the structure of the vertebral body to be inserted, it is possible to reduce manufacturing costs and to effectively cope with surgical and surgical problems, and the insertion direction may be forward, rearward, and laterally, and thus, operation time Can reduce the risk of the patient.

According to the present invention, it is easy to insert between the vertebral bodies, and after the insertion, it is possible to prevent the departure of the intervertebral body and the displacement of the vertebral body from front to back, left and right, and to reduce the pain of the patient and smoothly progress the bone fusion, ultimately effective. Treatment is possible.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (10)

A central opening is formed to facilitate the fusion of tissues and bones of adjacent vertebral bodies, and the front part that first enters when intervertebral interbody insertion; Left and right sides extending from the front side and facing each other, and having a plurality of side openings connected to the central opening to facilitate bone fusion; Upper and lower surfaces respectively formed on the upper and lower surfaces of the left and right sides, the upper and lower surfaces formed with one or more threaded projections to prevent movement by contact with the vertebral body during intervertebral insertion; And An elongated hexahedral intervertebral fusion cage having an elongated hexahedral shape extending from the left and right sides and facing the front part, and having one or more fixing pins formed on an upper surface or a lower surface to prevent movement during intervertebral insertion. The cage for intervertebral fusion surgery according to claim 1, wherein the anterior portion is curved to facilitate intervertebral insertion. The cage for intervertebral fusion surgery according to claim 1, wherein the upper and lower surfaces are formed to have an inclination angle, and the intervertebral fusion surgery is easy to insert. 4. The cage for interbody fusion surgery according to claim 3, wherein the inclination angle is 0 to 8 degrees. The intervertebral fusion fusion cage according to claim 1, wherein an inclination in the front direction of the screw thread and an inclination in the rear direction of the screw thread are formed differently to facilitate intervertebral interbody insertion. 2. The cage for interbody fusion surgery according to claim 1, wherein the central opening formed in the front portion communicates with the rear portion. The cage for intervertebral fusion surgery according to claim 6, wherein a female screw is formed inside the central opening to facilitate intervertebral insertion. The cage for intervertebral fusion surgery according to claim 1, wherein a locking groove or a locking jaw is formed in part or all of the threads to prevent movement between the vertebral bodies. The intervertebral fusion fusion cage according to claim 1, further comprising a trim formed at a portion of the front portion, the rear portion, or the left and right side surfaces and capable of absorbing elasticity in the vertical direction between the vertebral bodies. 2. The cage for intervertebral fusion surgery according to claim 1, wherein the cage is made of one or more selected from the group consisting of polyether ether ketone, carbon, carbon composite material, titanium, titanium composite material and SUS 316L.