Bone fixing plate system

Abstract

To provide a bone fixing plate system capable of repairing a meniscus in a short time and maintaining a repaired state of the meniscus for a relatively long period.SOLUTION: A bone fixing plate system includes: a plate member 1 that contacts a tibia K; and a screw 2 that fixes the plate member 1 to the tibia K by screwing into the tibia K via the plate member 1. The plate member 1 includes a projection part (pressing force fixation part) 4 that projects toward a lower part of a meniscus H and presses a tissue extending to the tibia K from the meniscus H.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bone fixation plate system for restricting meniscal motion. [Background technology]

[0002] The meniscus is sandwiched between the articular surfaces of the femur and tibia in the knee joint, and acts like a cushion to absorb various stresses on the knee joint, such as body weight and shear force. The meniscus does not contain cells, but is composed of a fibrous structure. Therefore, the meniscus can tear due to deterioration associated with aging, and once torn, it is extremely difficult to repair itself.

[0003] Therefore, as a method for repairing the meniscus, for example, a method of suturing the torn portion with sutures is known (see, for example, Patent Document 1).

[0004] Other methods of meniscal repair include meniscal posterior root repair and meniscal centralization.

[0005] Posterior meniscal root repair is a method in which a hole is formed near the original position of the posterior root of the torn meniscus, and an artificial ligament is sewn to the stump of the meniscus and pulled into the hole to fix it.

[0006] Meniscus centralization involves driving multiple anchors (made of special thread) into the medial or lateral edge of the tibia at regular intervals to pull the damaged meniscus, which has shifted inward or outward, back toward the center of the knee, thereby restoring its cushioning function. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2014-519871 Summary of the Invention [Problem to be solved by the invention]

[0008] However, all of the above conventional methods have the disadvantage of requiring a long time for the procedure because they are performed in a small space using an arthroscope (endoscope).In addition, there are also disadvantages such as the sutures becoming stretched, making it difficult to maintain the repaired state of the meniscus.

[0009] In view of the above-mentioned conventional disadvantages, an object of the present invention is to provide a bone fixation plate system that can repair the meniscus in a short period of time and maintain the repaired state of the meniscus for a relatively long period of time. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention provides a bone fixation plate system including a plate member that is brought into contact with a tibia, and a screw that fixes the plate member to the tibia by being screwed into the tibia through the plate member, the plate member includes a pressing and fixing portion formed from an upper end of the plate member toward a lower portion of the meniscus, and pressing against tissue extending from the meniscus to the tibia to fix the meniscus; When the plate member is abutted against the tibia across an incision formed by a proximal tibial osteotomy or the like, The screw that is screwed into the tibia through the plate member is characterized in that it is screwed into the tibia so as to cross the plane of the notch.

[0011] According to the present invention, simply by fixing the plate member to the tibia with screws, the pressure fixing portion provided on the plate member presses the tissue extending from the meniscus to the tibia, fixing the meniscus to its original position. This allows meniscus repair to be performed in a short time, and the meniscus can be maintained in a fixed state for a relatively long period of time.

[0012] Furthermore, in the present invention, when the plate member is abutted against the tibia across an incision formed by proximal tibial osteotomy or the like, the screw screwed into the tibia through the plate member is screwed into the tibia while crossing the plane of the incision.

[0013] This allows the notched portion of the tibia to be firmly fixed in the most favorable state.

[0014] Furthermore, in the present invention, the plate member has a threaded hole portion through which the screw is inserted and screwed, and the screw has a first threaded portion that screws into the bone and a second threaded portion that screws into the threaded hole portion of the plate member, and the thread pitch of the first threaded portion is larger than the thread pitch of the second threaded portion.

[0015] This allows the screw to be threaded into the bone to a large extent even if the rotation angle of the screw when threading the screw into the plate member is relatively small, and the plate member and bone can be sufficiently pressed together.

[0016] In addition, in the present invention, the plate member is characterized in that it has a communicating threaded hole portion having two adjacent holes that communicate with each other, and the communicating threaded hole portion is formed so that the two holes guide the insertion of the screw in different directions.

[0017] This allows the screw to be inserted through one of the two holes of the communicating threaded hole portion, and the screw can be easily screwed in in a preferred direction by this selection. [Brief explanation of the drawings]

[0018] [Figure 1] 1A and 1B are explanatory views showing a state in which the bone fixation plate system according to an embodiment of the present invention is used. [Figure 2] FIG. [Figure 3] FIG. 3A shows the first screw, and FIG. 3B shows the second screw. [Figure 4] FIG. [Figure 5] FIG. 10 is an explanatory plan view showing a modified example of the protrusion. [Figure 6] FIG. 10 is an explanatory plan view showing another modified example of the protrusion. [Figure 7] FIG. 10 is an explanatory diagram showing another example of mounting the plate member. [Figure 8] FIG. 6 is an explanatory diagram showing a communicating screw hole portion of a plate member. [Figure 9] 9A is an explanatory diagram schematically showing a screw-insertion posture using one of the threaded hole portions in FIG. 8, and FIG. 9B is an explanatory diagram schematically showing a screw-insertion posture using one of the threaded hole portions in FIG. 8. FIG. [Figure 10] FIG. 10 is an explanatory diagram showing a modified example of the plate member. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described with reference to the drawings. As shown in Figure 1, the bone fixation plate system according to this embodiment is composed of a plate member 1 and a plurality of screws 2, and is used by fixing it to the higher lateral surface of the tibia K.

[0020] The plate member 1 is a plate-like member that is fixed to the high medial surface of the tibia K after osteotomy in proximal tibial osteotomy for knee osteoarthritis, and is formed in a generally T-shape overall. Note that, although the present embodiment shows an example in which the plate member 1 is fixed to the high medial surface of the tibia K, proximal tibial osteotomy may also be performed from the outside, in which case the plate member 1 is fixed to the high lateral surface of the tibia K.

[0021] 2, the plate member 1 is formed with a plurality of screw holes 3 through which screws 2 can be inserted. In addition, the upper end of the plate member 1 is provided with a protrusion 4 (corresponding to the pressing and fixing portion of the present invention).

[0022] As is well known, there are several types of screws 2, and the screw 2 can be appropriately selected depending on the position to be screwed in. For example, a first screw 2A shown in FIG. 3A or a second screw 2B shown in FIG. 3B can be used.

[0023] As shown in Figure 3A, the first screw 2A has a small-diameter body portion 6 with a first screw portion 5 formed on its outer peripheral surface, and a large-diameter head portion 8 with a second screw portion 7 formed on its outer peripheral surface, and the thread pitch 5P of the first screw portion 5 and the thread pitch 7P of the second screw portion 7 are formed to be the same dimension.

[0024] As shown in Figure 3B, the second screw 2B has a small-diameter body 10 with a first thread portion 9 formed on its outer surface and a large-diameter head 12 with a second thread portion 11 formed on its outer surface, and the thread pitch 9P of the first thread portion 9 is formed to be larger than the thread pitch 11P of the second thread portion 11.

[0025] In both the first screw 2A and the second screw 2B, the main body portions 6, 10 are screwed into the bone, and the head portions 8, 12 are screwed into the screw hole portion 3 of the plate member 1.

[0026] When the first screw 2A is used, the screwing depth of the main body 6 into the bone and the screwing depth of the head 8 into the plate member 1 become the same depending on the rotation angle of the first screw 2A.

[0027] On the other hand, when the second screw 2B is used, when the second screw 2B is rotated, the depth of penetration of the main body 10 into the bone becomes deeper than the depth of penetration of the head 12 into the plate member 1. This reduces the number of rotations of the second screw 2B, allowing the main body 10 to be quickly screwed into the bone, and also increasing the degree of pressure contact of the plate member 1 against the bone.

[0028] Furthermore, by forming the thread pitch 7P of the second screw portion 7 of the first screw 2A and the thread pitch 9P of the first screw portion 9 of the second screw 2B to the same dimensions, the thread pitch of the threaded hole portion 3 of the plate member 1 can be made common, and the first screw 2A and the second screw 2B can be freely selected and replaced.

[0029] In this embodiment, as shown in Figures 3A and 3B, both the first screw 2A and the second screw 2B have first thread portions 5, 9 formed over approximately the entire length of the main body portions 6, 10, but this is not limited to this, and although not shown, a type of screw called a half thread, in which the first thread portion is provided in the tip half of the main body portions 6, 10, can be used as needed.

[0030] As shown in FIG. 1, the protruding portion 4 of the plate member 1 is formed in a shape that protrudes toward the lower portion of the meniscus H when the plate member 1 is fixed to the tibia K.

[0031] By providing the protrusions 4 on the plate member 1, when the plate member 1 is fixed to the tibia K, the protrusions 4 simultaneously press against the tissue extending from the meniscus H to the tibia K, thereby fixing the meniscus H to its original position. This allows the meniscus H to be repaired in a short time, and the fixed state of the meniscus H can be maintained for a relatively long period of time.

[0032] The protrusion 4 may be composed of a plurality of projections 13 with sharp tips, as shown in Figure 2 and Figure 4, or may be composed of a plurality of projections 14 with blunt tips, as shown in Figure 5. Alternatively, the protrusion 4 may be composed of a continuous ridge 15, as shown in Figure 6.

[0033] 7, the screw 2 may be screwed into the tibia K so as to cross the plane Ka of the bone notch. In proximal tibia osteotomy, the plate member 1 is brought into contact with the high medial surface (or lateral surface) of the tibia K so as to straddle the notch after the osteotomy, and the plate member 1 can be firmly compressed and fixed to the tibia K by the screw 2 that crosses the bone notch surface Ka.

[0034] This allows the tibiae K to be pressed against each other via the incisions made after the osteotomy, increasing the degree of adhesion, and at the same time, a state in which the tissues extending from the meniscus H to the tibiae K are strongly compressed can be created.

[0035] 8, a communicating threaded hole portion 16 having two communicating holes may be provided in the plate member 1. The communicating threaded hole portion 15 is formed so that two holes 16a, 16b guide the insertion of the screw 2 in different directions.

[0036] That is, as shown in Figure 9a, when a screw 2 is inserted into one hole 16a of the communicating threaded hole portion 16 and screwed, the screw 2 is screwed diagonally downward into the bone, and as shown in Figure 9b, when a screw 2 is inserted into the other hole 16b of the communicating threaded hole portion 16 and screwed, the screw 2 is screwed diagonally upward into the bone.

[0037] As shown in Figure 8, both of the two holes 16a, 16b of the communicating threaded hole portion 16 are formed with female threads (not shown), but this is not limited to this, and either or both of the two holes 16a, 16b may not have threads depending on the screw to be used.

[0038] As described above, according to the bone fixation plate system of this embodiment, as is clear from Fig. 1, by providing the protrusions 4 on the plate member 1, simply fixing the plate member 1 to the tibia K allows the protrusions 4 to press against the tissue extending from the meniscus H to the tibia K, thereby fixing the meniscus H to its original position. Therefore, the meniscus H can be repaired in a short time, and the fixed state of the meniscus H can be maintained for a relatively long period of time. Furthermore, movement of the meniscus H can be restricted, preventing the meniscus H from escaping.

[0039] In this embodiment, the description has been given taking the plate member 1 having a vertically long shape as an example, but instead, as shown in Fig. 10, a short plate member 17 may be adopted and the plate member 17 may be fixed with, for example, one screw 2. This also allows the protrusion 4 provided on the plate member 1B to press against the tissues extending from the meniscus H to the tibia K. [Explanation of symbols]

[0040] K...tibia, H...meniscus, Ka...notch surface, 1, 17...plate member, 2...screw, 2A...first screw (screw), 2B...second screw (screw), 3...screw-engaging hole portion, 4...protrusion portion (pressure fixing portion), 5...first screw portion, 7...second screw portion, 16...communicating screw-engaging hole portion, 16a, 16b...holes.

Claims

1. A bone fixation plate system comprising a plate member to be brought into contact with a tibia, and a screw for fixing the plate member to the tibia by being screwed into the tibia through the plate member, the plate member includes a pressing and fixing portion formed from an upper end of the plate member toward a lower portion of the meniscus, and pressing against tissue extending from the meniscus to the tibia to fix the meniscus; When the plate member is abutted against the tibia across an incision formed by a proximal tibial osteotomy or the like, A bone fixation plate system, characterized in that the screw that is screwed into the tibia through the plate member is screwed into the tibia crossing the plane of the notch.

2. the plate member has a threaded hole portion into which the screw is inserted and threadedly engaged; The screw includes a first screw portion that is screwed into a bone and a second screw portion that is screwed into a screw hole portion of the plate member, 2. The bone fixation plate system according to claim 1, wherein the thread pitch of the first threaded portion is greater than the thread pitch of the second threaded portion.

3. the plate member includes a communicating threaded hole portion having two adjacent holes communicating with each other; 3. The bone fixation plate system according to claim 1, wherein the communicating threaded hole portion is formed so that two holes guide the insertion of the screw in different directions.

Images