JPH05277132A - Bone fixing device - Google Patents

Abstract

PURPOSE:To provide the bone fixing device which facilitates the deformation and fine adjustment of a fixing member in a surgery place corresponding to various disease conditions, can firmly fix a bone to be reformed and fixed, does not occur compression fracture of bone, etc., and does not flaw the periphery of bone nor damages blood vessel. CONSTITUTION:A bone is reformed and fixed by the bone fixing device 10 in which a rod 40 being a curing member and a plate 50 being a fixing member are installed in three pieces of screw bodies formed by an outer cylindrical member 20 having a thread ridge screwed to the bone in the outside periphery, and internal screw member 30 which is provided with a bolt for fixing the plate being a holding member and a fixing member for holding and fixing the rod being a curing member by a nut 60, and inserted and provided in the outer cylindrical member 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bone fixing device useful for correcting the curvature of the spine (thoracic vertebrae, lumbar vertebrae, cervical vertebrae) in the field of orthopedic surgery, fixing bones such as for treating spondylolisthesis and the like.

[0002]

2. Description of the Related Art Conventionally, for fixing a bone, a plurality of screw bodies are embedded in a bone, and the screw bodies are connected by a fixing member such as a fixing rod or a plate to fix the bone and correct bone misalignment. Various devices have been proposed.

However, in the conventional bone fixing device, since a plurality of screw bodies are connected and fixed by one fixing member, the fixing member is large in order to exert sufficient fixing strength. However, there is a problem in that it is difficult to deform the fixing member in the surgical field according to various symptoms, because it has to be thick. There is also a problem that fine adjustment is difficult when the bone is installed because the bone is corrected and fixed by one fixing member.

Further, in order to stably screw the screw body to the bone, it is necessary to lengthen the portion of the screw body embedded in the bone. Especially, when the bone to be fixed is osteoporosis or the like, The portion to be embedded in the bone, it is necessary to have a length that penetrates the bone and is applied to both ends of the cortex of the bone,
There is a problem in that there is a high risk of damaging or damaging blood vessels, nerves, etc. located around the bone due to compression fracture by the screw body or penetration of the screw body into the bone.

When the bone fixing device is used for the spine or the like, there is a demand for a device that can be installed by posterior open surgery in order to reduce the burden on the patient and the operator.

[0006]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to easily deform and finely adjust the fixing member in the operating field according to various symptoms, and firmly fix the bone for correction and fixing. The object is to provide a bone fixation device that can be used.

Another object of the present invention is to provide a bone anchoring device which does not cause a compression fracture of the bone or the like and does not damage the periphery of the bone or damage the blood vessel.

[0008]

According to the present invention, there is provided a bone fixing device comprising a plurality of screw bodies screwed to bone and a fixing member for connecting the screw bodies to fix bone. There is provided a bone anchoring device, wherein the member comprises a reduction member and a fixing member.

Further, according to the present invention, there is provided a bone fixing device comprising a plurality of screw bodies screwed to a bone and a fixing member for connecting the screw bodies to fix the bone.
There is provided a device for bone fixation, wherein the screw body has a double structure composed of an outer cylinder member and an internal screw member inserted into the outer cylinder member.

The term "duplexing member" as used in the present invention means that a plurality of screw bodies screwed to a bone are connected to each other in a finely adjustable and form-correctable state to correct bone misalignment, etc. It is a member for temporarily fixing in a state, and a rod shape, a plate shape or the like which is usually used as a fixing member can be used.

Further, in the present invention, the fixing member is a member for firmly fixing the temporarily fixed compounding member and each screw body to maintain the normal state of the bone, and has a rod shape which is usually used. A plate shape or the like can be used.

At this time, the compounding member and the fixing member are
It can be made smaller and thinner than conventional fixing plates or rods, and in particular, the compounding member can be made of a material that can be deformed as desired.

In the present invention, the outer cylinder member of the double-structured screw body may be provided with a plurality of holes for connecting the outer peripheral surface and the inner peripheral surface. As a result, new bone tissue invades the holes to improve the stability of the screw body.

Further, the outer cylinder member may be provided with expanding means for expanding outward by inserting an internal screw member, and the stability of the screw body is improved by the expanding means. You can

The bone fixing device of the present invention can be applied to any bone as long as it is a bone for fixing, but it is particularly effective to use it for fixing the spine.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings, but the present invention is not limited to these.

In FIG. 1, reference numeral 10 denotes an outer cylinder member 20 having a screw thread on its outer periphery to be screwed into a bone for fixing, and a holding member 3 for holding and fixing a rod 40 as a reduction member.
4 and a bolt 32 for fixing a plate 50 as a fixing member with a nut 60, and an inner screw member 30 inserted into the outer cylinder member 20 and formed with 3
This is a bone fixing device in which a rod 40 as a reduction member and a plate 50 as a fixing member are installed on each screw body.

Next, the bone fixing device 10 and each member will be described in detail with reference to FIGS. 1 and 2.

The outer tubular member 20 is a tubular body having a thread 21 on the outer peripheral surface and an opening 22 for inserting the internal screw member 30 in the central portion thereof, and the opening 22 is formed. A screw thread is provided on the inner peripheral surface of the outer tubular member 20.

On the other hand, the internal screw member 30 has an insertion portion 31 for being screwed into the opening 22 of the outer tubular member 20 for insertion, and a hole 33 into which the rod 40 can be inserted. A holding member 34 formed in a rectangular shape having an opening 35 for finely adjusting the state and a bolt 32 for fixing the plate 50 with a nut 60 are provided.
The holding member 34 is formed on the upper portion of the insertion portion 31, and the bolt 32 is provided so as to protrude from the central portion of the upper surface of the holding member 34.

The rod 40 has a cylindrical shape so that it can be held by the holding member 34 of the internal screw member 30. Further, the plate 50 is provided with a continuous hole 51 into which the bolt 32 provided on the internal screw member 30 is fitted and which is fixed to the bolt 32 by the nut 60. That is, in order to form the bone fixation device 10 as shown in FIG. 1, first, each outer cylinder member 20 is attached to the bone for fixation.
Is screwed and embedded, and the insertion portion 31 of the internal screw member 30 is screwed into the opening 22 of the outer tubular member 20. At this time, in order to further increase the stability of the internal screw member 30, the insertion portion 31 may be inserted after the biocement is injected through the opening 22 of the outer tubular member 20. As the biological cement, conventionally used polymethylmethacrylate, calcium phosphate cement, a mixture of calcium phosphate cement and hydroxyapatite granules and the like can be preferably used, and particularly calcium phosphate cement and hydroxyapatite capable of forming a porous body. A mixture with is preferred. Then, the holes 33 of each holding member 34
After that, the rod 40 is inserted, and fine adjustment such as correction of the bone to be fixed is performed to temporarily fix it, and then the plate 50 is fixed. The plate 50 can be fixed by inserting the bolts 32 into the corresponding holes 51 and fixing the nuts 60.
At this time, since the opening 35 of the holding member 34 is tightened by fixing the bolt 32, the temporarily fixed rod 40 is fixed.
Are completely fixed together with the plate 50.

FIG. 3 is a partially transparent perspective view of the bone fixing device 10 fixed to the lumbar spine by the above procedure.

In FIG. 4, reference numeral 20a denotes another embodiment of the outer tubular member 20 shown in FIGS. 1 to 3, which is provided with a plurality of holes 23 through which the outer peripheral surface provided with threads and the inner peripheral surface communicate with each other. It is a tubular member. By using such an outer cylinder member 20a, new bone tissue penetrates into the plurality of holes 23, and the fixability of the screw body is further improved. Further, with such a shape, the length of the screw body can be made shorter than in the conventional case, and therefore, the screw body can be operated under direct view during surgery.

Further, in FIG. 5, reference numeral 20b designates a further embodiment of the outer tubular member 20 shown in FIGS. is there. The outer cylinder member 20b is expanded outward along the gradual taper portion 26 by screwing and inserting the inner screw member 30, so that the stability of the screw body against bone is further improved. Can be made.

The above-described bone anchoring device of FIGS.
Although a reduction member and a fixing member as a fixing member and a screw body having a double structure are provided, each single fixing member or screw body may be combined with a conventional fixing member or screw body.

Next, in order to compare the bone fixing device shown in FIG. 1 with a conventional Utrell type bone fixing device, each was fixed to the thoracic vertebra of a pig, and four weeks later, the pig was sacrificed,
The insertion part was visually observed. As a result, no difference was observed, but when the pull-out strength was measured with a universal testing machine manufactured by Instron, the bone fixation device shown in FIG. 1 showed a value 20% higher.

[0027]

EFFECTS OF THE INVENTION In the bone fixing device of the present invention, the fixing member has a double structure including a reduction member for correcting bone misalignment and the like and temporarily fixing it, and a fixing member for fixing the corrected bone. Therefore, it is possible to easily correct the shape during the operation and finely adjust it, and further, it is possible to reduce the weight of the fixing member.

Further, in the bone fixing device of the present invention, since the screw body screwed into the bone has a double structure of the outer cylinder member and the inner screw member, the fixation to the bone can be made firm and the screw itself. The length of can be shortened. Therefore, the screw body can be stably screwed onto the bone without damaging the tissue around the bone. Further, by providing the outer cylinder member with a plurality of holes and expansion means, the effect of fixing to the bone can be further enhanced.

[Brief description of drawings]

FIG. 1 is a perspective view of a bone anchoring device of the present invention.

FIG. 2 is a partially exploded perspective view of the bone anchoring device of the present invention.

FIG. 3 is a partially transparent perspective view showing an example in which the bone fixing device shown in FIG. 1 is used for fixing the lumbar spine.

FIG. 4 is a perspective view showing another example of an outer cylinder member having a plurality of holes.

FIG. 5 is a cross-sectional view showing an example in which an internal screw member is installed on an outer cylinder member provided with a spreading means. 10 Bone Fixing Device 20 Outer Cylinder Member 30 Internal Screw Member 40 Rod 50 Plate 60 Nut

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Hirano 2270 Yokoze, Yokose-cho, Chichibu-gun, Saitama Sanritsu Materials Co., Ltd., Ceramics Laboratory (72) Inventor Moto Sakai 1-297 Kitabukuro, Omiya-shi, Saitama Mitsubishi Central Research Institute, Material Co., Ltd. (72) Inventor Takeaki Sahira 1-297 Kitabukuro-cho, Omiya City, Saitama Prefecture Mitsubishi Materials Co., Ltd. Central Research Center

Claims (4)

[Claims] 1. A plurality of screw bodies screwed to a bone,
A bone fixing device comprising a fixing member for connecting the screw body to fix bone, wherein the fixing member comprises a reduction member and a fixing member. 2. A plurality of screw bodies screwed to a bone,
In a bone fixation device comprising a fixing member that connects the screw bodies to fix bones, the screw body is
A bone fixing device having a double structure comprising an outer cylinder member and an internal screw member inserted into the outer cylinder member. 3. The bone fixing device according to claim 2, wherein the outer cylinder member has a plurality of holes that connect the outer peripheral surface and the inner peripheral surface. 4. The bone fixing device according to claim 2, wherein the outer cylinder member has an expanding means that expands outward by inserting an internal screw.