JP2004216056A - Implant member for thigh bone fracture treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an implant member for thigh bone fracture treatment which allows the angle between a capital shaft member and a plate to be adjustable, with an angle adjusting part of the smallest possible structure, and can resist heavier load than conventional angle-adjustable implant members. <P>SOLUTION: The lower end part of a capital shaft member 32 is rotatably connected with the upper end part of a plate 11 through a connecting shaft 123, with a male screw member 136 being screwed into a screw hole 135 formed on a plate 11, where the lower end part 32a of the capital shaft member 32 is directly fitted thereto. With the rotary operation (A) of the male screw member 136, the capital shaft member 32 can be rotated (D) around the connecting shaft 123 as a center to change the connection angle. As the angle adjusting part is made compact with fewer components than the conventional one, using only the integrated male screw member 136, this implant member can resist heavier load than the conventional implant members. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to an implant member used for fixation treatment of a bone in a treatment when a fracture near a femoral head is performed.
[0002]
[Prior art]
Conventionally, fractures occur frequently in the vicinity of the femoral head where a large load is applied. Therefore, using an implant member in which the shaft member for the head and the plate are connected in a く shape, the fractured bone is formed into a desired shape. Retention treatment has been performed.
[0003]
FIG. 8 is a cross-sectional view illustrating a state in which an implant member is attached near the fractured femoral head, in which the femoral head 15 and the femoral shaft 16 are fractured at the femoral neck 18. The shaft member 10 for the head of the head is inserted into the head 15 of the fractured femur, and the plate 11 connected to the shaft member 10 of the head is fixed along the shaft 16 by the screw member 13. The neck 18 is connected and fixed (conventional example 1).
[0004]
In the implant member of Conventional Example 1, the angle formed between the shaft member 10 for the head of the head and the plate 11 is fixed. However, the angle formed between the head of the femur and the diaphyseal part varies from person to person. It was necessary to prepare implant members at various angles. Therefore, various implant members have been proposed in which the angle between the shaft member for the head and the plate is variable (for example, see Patent Documents 1 to 3).
[0005]
Above all, in the implant member disclosed by the present inventors in Patent Document 3, as shown in FIG. 9, the angle formed by the femoral tube 32 and the plate 11, which constitute a part of the shaft member for the head, is formed. It is connected via a connecting shaft 34 so as to be changeable, and as shown in FIGS. 10A to 10C, the first operating member 35 (male screw 35b) is rotated to operate the second operating member 36 ( Since the female screw 36b and the convex portion 36a) are moved, and the concave portion 36c is moved by this movement, the femoral tube 32 is rotated around the connection shaft 34, and the angle (connection angle) is changed. In addition, the connection angle can be finely adjusted during the operation, and the portion that projects outside the bone is small, so that the patient's burden such as discomfort and pain when pressed is reduced, and the large load on the head of the bone after the operation can be reduced. Can resist An excellent implant member (Conventional Example 2).
[0006]
However, there is a demand for further miniaturizing the structure of the angle adjusting portion compared to the implant member of the above-mentioned conventional example 2 in order to reduce as much as possible the discomfort and the pain when the patient is squeezed after being placed in the body. In addition, in order to extend the life of the implant member, there is a demand for a structure of an angle adjusting portion capable of resisting a larger load. However, in the implant member of Conventional Example 2 described above, simply reducing the structure of the angle adjusting unit to a size smaller than the current state cannot resist a large load from the bone head, and shortens the life of the device. On the other hand, if the structure of the angle adjusting section is increased to resist a larger load, the discomfort given to the patient and the pain when pressed are increased. Therefore, the above two requirements could not be satisfied at the same time.
[0007]
[Patent Document 1]
Japanese Patent Publication No. 7-509621 [Patent Document 2]
US Pat. No. 3,554,193 [Patent Document 3]
Japanese Patent No. 3137905 [0008]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to make the angle formed by the shaft member for the head and the plate variable, and to reduce the structure of the angle adjusting section as much as possible while resisting a larger load than the conventional variable angle implant member. It is an object of the present invention to provide an implant member for treating a femoral fracture.
[0009]
[Means for Solving the Problems]
An implant member for treating a femoral fracture according to the present invention (the first invention) includes a shaft member for a head to be embedded in a head of a femur and a shaft member connected to a lower end portion of the shaft member for a femur and an outer surface of a shaft portion of the femur. A plate fixed along with the implant member connected via a connecting shaft so that an angle between the plate and the plate fixed to the plate can be changed, wherein the plate has a screw hole extending from the non-contact surface side to the femur shaft side. A male screw member that is moved by a rotation operation from the opposite contact surface side is screwed into the screw hole, and the male screw member is moved relative to the plate in conjunction with the movement of the male screw member. The head member is fitted so that an angle formed by the head member changes.
[0010]
The “opposite surface” refers to a surface on the opposite side to the surface in contact with the femoral shaft when the plate is fixed along the outer surface of the femoral shaft, that is, the outer surface.
[0011]
According to the present invention (first invention), since the shaft member for the head is fitted so that the angle formed by the shaft member for the head with respect to the plate in conjunction with the movement of the male screw member, the conventional example 2 Like the implant member, the angle between the plate and the shaft member for the head can be adjusted during the operation according to the angle between the bone head and the diaphyseal part, which has individual differences. Further, while the implant member of Conventional Example 2 requires two actuating members (first actuating member 35 and second actuating member 36 in FIG. 10) as angle adjusting means, according to the present invention, these functions are male Since the number of parts is reduced by consolidating the screw members, the size can be further reduced as compared with the angle adjusting unit of the second conventional example. Further, since the number of parts of the angle adjusting section is omitted and the male screw member is concentrated, the diameter of the male screw member can be made larger than the diameter of the first operating member (male screw) of Conventional Example 2, and the load can be reduced. The supporting area is increased, so that a larger load can be resisted.
[0012]
In the implant member for treating a femoral fracture according to the present invention (the second invention), in the first invention, the male screw member has a concave portion in which a part of the male screw member is cut out over the entire circumference, while the shaft member for the head is It has a convex portion at its lower end, and the convex portion is slidably fitted in the concave portion.
[0013]
Since the concave portion obtained by cutting out a part of the male screw member over the entire circumference and the convex portion provided at the lower end of the shaft member for the head are slidably fitted, the shaft member for the head from the male screw member There is no risk of coming off, and in conjunction with the movement of the male screw member, the head shaft member rotates smoothly around the connection shaft, and the angle formed by the head head shaft member with respect to the plate can be accurately changed. (1) The effect of the invention can be made more reliable.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an implant member for femur osteosynthesis according to the present invention will be described in detail with reference to the drawings. FIGS. 1A and 1B are views showing the entire femoral osteosynthesis implant member according to the embodiment of the present invention, wherein FIG. 1A is a front view and FIG. 1B is a side view. FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG. 3 is a cross-sectional view illustrating the structure of the angle adjustment unit. FIG. 4 is a view for explaining an angle fixing mechanism which is not an essential component of the present invention. FIG. 4 (a) is a side view of the femoral shaft, and FIG. 4 (b) shows a state before the angle is fixed. FIG. 3C is a cross-sectional view showing a state after the angle is fixed.
[0015]
The implant member of the present embodiment is made of a biocompatible material, for example, a titanium alloy or the like because it is embedded in a living body, and as shown in FIGS. The femoral shaft member 10 is formed by the femoral tube 32 into which the lower end of the lag screw 33 is inserted, and the angle between the upper end of the plate 11 and the lower end of the femoral tube 32 is changed so that the angle between them can be changed. It is connected in the shape of a “ku” through the adjustment unit 20.
[0016]
The angle adjusting unit 20 has a configuration shown in FIG. That is, the lower end of the femoral tube 32 and the upper end of the plate 11 are rotatably connected via the connection shaft 123. A screw hole (first screw hole) 135 is formed in the plate 11 from the non-contact surface 11a side to the femur shaft side (11b side), and the first screw hole 135 has a male screw member (first screw hole). (1 male screw member) 136 is screwed together, and is configured to move in the first screw hole 135 by a rotation operation from the non-contact surface 11a side. Further, as shown in FIG. 3, for example, a concave portion 136a is formed by cutting a part of the first male screw member 136 over the entire circumference, and a convex portion slightly smaller than the concave portion 136a is formed at the lower end of the femoral tube 32. 32a is formed, and the convex portion 32a is fitted into the concave portion 136a. Thus, the first male screw member 136 moves in the first screw hole 135 by the rotation operation (A) (B), and the projection 32a also moves in the same direction (C), and the femoral tube 32, that is, the head of the femur. The shaft member 10 for rotation rotates about the connecting shaft 123 (D), and the angle between the plate 11 and the shaft member 10 for the head changes. According to the present invention, since the number of components is reduced compared to the implant member of the conventional example 2, the portion where the first male screw member 136 and the first screw hole 135 are screwed becomes wider, and this screwing is performed. The whole portion receives the load from the bone, and can sufficiently resist even the load larger than that of the implant member of the conventional example 2.
[0017]
It is preferable to provide the implant member of the present invention with an angle fixing mechanism. That is, since the implant member of Conventional Example 2 does not have an angle fixing mechanism, there is a possibility that the angle adjustment unit may become loose due to frequent load fluctuations or vibrations in daily life after the implant member is installed in the patient. This is because there is a possibility that the connection angle may change.
[0018]
FIG. 4 shows an example of the angle fixing mechanism. In the first male screw member 136, another screw hole (second screw hole) 137 is formed from the non-contact surface 11a side to the femur shaft side (11b side). Another male screw member (second male screw member) 138 that is moved by a rotation operation from the non-contact surface 11a side is screwed together. Then, for example, as shown in FIG. 4B, one end side of the second screw hole 137 (in FIG. 4B, the side of the femur shaft [11b side]) is at least smaller than the diameter of the second male screw member 138. A tapered portion 137b tapered to a diameter is formed, and a slit 136c is provided radially from the center axis of the male screw member 136 on the tapered portion 137b side of the male screw member 136. As a result, the second male screw member 138 moves in the second screw hole 137 by the rotation operation (E) from the opposite contact surface 11a side, and the distal end portion 138a of the second male screw member 138 comes into contact with the tapered portion 137b. Further, by continuing the rotation operation (E), the distal end portion 138a is pushed into the tapered portion 137b, thereby expanding the gap of the slit 136c and expanding the diameter of the tapered portion 137b side of the first male screw member 136 (φd ₁ → φd ₂ ; where d ₁ <d ₂ ), which is pressed against the inner surface of the first screw hole 135 and fixed by frictional force.
[0019]
As shown in FIGS. 4B and 4C, it is preferable that the distal end portion 138a of the second male screw member 138 is formed in a tapered shape along the tapered portion 137b of the second screw hole 137. Accordingly, when the second male screw member 138 is tightened, the tapered portion 137b and the tip 138a of the second male screw member 138 come into contact with each other over a wide area, so that it can be fixed with a strong frictional force.
[0020]
If the depth of the slit 136c is too shallow, it is difficult to increase the diameter. On the other hand, if it is too deep, the strength of the first male screw member 136 is reduced. About / 4 is a preferable range. If the number of the slits 136c is one or more, the above-described effects can be obtained. However, the diameter of the first male screw member is increased as uniformly as possible in the circumferential direction to increase the contact area with the first screw hole 135. It is recommended that the number be about 3 to 6 in consideration of the processing time of the slit 136c and the strength of the first male screw member (four in FIG. 4A).
[0021]
Further, as shown in FIG. 4, when the tapered portion 137b is formed on the femur shaft side (11b side), the second male screw member 138 can be screwed in while being pressed against the femur shaft side (11b side). Therefore, the operability is good and desirable. However, the present invention is not necessarily limited to this. Even if the tapered portion 137b is provided on the side opposite to the contact surface 11a, the same operation and effect can be obtained.
[0022]
Further, as shown in FIGS. 2 and 3, the lag screw 33 is slidably inserted in the axial direction of the femoral tube 32 in the cylinder, so that the fusion of the head and the diaphysis can be promoted. it can. Further, in order to prevent a so-called cutout in which the lag screw 33 breaks through the head of the bone, it is preferable that the tip of the lag screw 33 on the side of the head be spherical.
[0023]
FIG. 5 is a cross-sectional view showing a state in which the thus configured implant member according to the present invention is attached to a femur (a case in which a greater trochanter is fixed with a screw member). The procedure for attaching the implant member according to the present invention to the femur will be described with reference to FIG. In this example, it is assumed that a fracture has occurred in the neck 18. The bone head 15 separated from the diaphyseal part 16 by the fracture is pressed against the diaphyseal part 16, drilled at a predetermined angle using a drill and a tap, and a lag screw 33 fitted into the femoral tube 32 is inserted into the hole. Screw it into the bone head 15. The plate 11 is integrally attached to the lower end of the femoral tube 32 via an adjustable unit (angle adjustment unit) 20. Before completely tightening the lag screw 33, the angle of the plate 11 is adjusted by rotating the angle adjusting screw (first male screw member) 136 of the adjustable unit (angle adjusting unit) 20 left and right using a driver or the like. After confirming that the plate 11 has become parallel to the surface of the diaphyseal part 16, the angle fixing screw (second male screw member) 138 is tightened to fix the angle adjusting screw (first male screw member) 136. The lag screw 33 is completely tightened to bring the plate 11 into close contact with the surface of the diaphysis 16, and a cortical screw (screw member 13) is screwed into the diaphysis 16 through a screw fitting hole 14 formed in advance in the plate 11. 11 is fixed along the surface of the diaphysis 16.
[0024]
Thus, by using the implant member of the present invention, the connection angle between the conventional femoral tube and the plate does not rise from the diaphyseal portion of the plate, which becomes a problem when using a fixed implant member. There is no need to prepare a plurality of implant members during the operation, and it is not necessary to replace the members during the operation. Therefore, it is possible to easily and quickly mount the implant members in an optimal state (close to the bone). .
[0025]
Further, in addition to omitting the number of components as compared with the implant member of Conventional Example 2, in addition to having a structure in which the second male screw member serving as the angle fixing means is incorporated in the first male screw member serving as the angle adjusting means. Despite the addition of the angle fixing function, further miniaturization has become possible.
[0026]
Further, by the addition of the angle fixing function, the angle adjusting section does not become loose after the operation, and the change of the connection angle is prevented, thereby enabling early and stable healing.
[0027]
The angle fixing mechanism is not limited to the structure shown in FIG. 4, but may be, for example, a structure shown in FIGS.
[0028]
The angle fixing mechanism shown in FIG. 6 is configured as follows. That is, a notch 139 is provided on the side surface of the first screw hole 135 along the axial direction, and another screw hole (second screw hole) 140 is formed so as to penetrate both side surfaces 139 a of the notch 139. Is provided. An angle fixing screw (second male screw member) 141 is screwed into the second screw hole 140. After adjusting the angle of the plate 11 by rotating the first male screw 136, the angle fixing screw (second male screw member) 141 is tightened. As a result, the gap between both side surfaces 139a of the cutout portion 139 is reduced to reduce the diameter of the first screw hole 135, so that the first male screw 136 is tightened and fixed in the first screw hole 135.
[0029]
The angle fixing mechanism shown in FIG. 7 is configured as follows. That is, another screw hole (second screw hole) 142 penetrating from the side surface of the first screw hole 135 to the outer surface of the angle adjustment unit 20 is provided, and the second screw hole 142 has an angle fixing screw (second male screw). Member 143 is screwed. Then, after adjusting the angle of the plate 11 by rotating the first male screw 136, the angle fixing screw (second male screw member) 143 is tightened until its tip is pressed against the first male screw 136. Thereby, the first male screw 136 is fixed.
[0030]
【The invention's effect】
According to the present invention, since the angle between the plate and the shaft member for the head can be adjusted, the plate and the head during the operation according to the angle between the bone head and the diaphyseal part, which have individual differences. The angle formed with the shaft member can be adjusted. In addition, compared to the conventional angle-variable implant member, the number of parts is reduced, so the size can be further reduced, the discomfort given to the patient can be greatly reduced, and a large load can be resisted. , The life of the device is extended, and early and stable healing becomes possible.
[Brief description of the drawings]
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an entire femoral bone implant member according to an embodiment of the present invention, wherein (a) is a front view and (b) is a side view.
FIG. 2 is a sectional view taken along line AA of FIG. 1 (b).
FIG. 3 is a cross-sectional view illustrating a structure of an angle adjustment unit.
4A and 4B are diagrams illustrating an angle fixing mechanism, wherein FIG. 4A is a cross-sectional view showing a state before the angle is fixed, and FIG. 4B is a cross-sectional view showing a state after the angle is fixed.
FIG. 5 is a cross-sectional view showing a state in which the implant member according to the present invention is attached to a femur (a case in which a greater trochanter is fixed with a screw member).
6A and 6B are diagrams illustrating another angle fixing mechanism, wherein FIG. 6A is a perspective view and FIG. 6B is a partial cross-sectional view.
7A and 7B are diagrams illustrating another angle fixing mechanism, wherein FIG. 7A is a perspective view and FIG. 7B is a partial cross-sectional view.
FIG. 8 is a cross-sectional view illustrating a state in which the implant member of Conventional Example 1 is attached to a femur.
FIG. 9 is a front view showing an implant member of Conventional Example 2.
10 (a) is a sectional view taken along the line BB of FIG. 9, and FIGS. 10 (b) and 10 (c) are CCs of FIG. 10 (a). It is a line sectional view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Head shaft member 11 ... Plate 11a ... Contact surface, 11b ... Femur shaft side 13 ... Screw member (cancer screw)
14 ... screw engagement hole (screw hole)
15: Femoral head 16: Femoral shaft 17: Greater trochanter 18: Femoral neck 20: Angle adjusting means (adjustable unit)
32 ... Femoral tube 32a ... Protrusion 33 ... Lag screw 123 ... Connection shaft 135 ... Screw hole (first screw hole)
136: male screw member (first male screw member)
136a: recess, 136c: slit 137: second screw hole 137b: taper 138: angle fixing screw (second male screw member)
138a: Tip 139: Notch 139a: Side surface 140: Second screw hole 141: Angle fixing screw (second male screw member)
142: second screw hole 143: angle fixing screw (second male screw member)

Claims (2)

The angle between the shaft member for the head to be embedded in the head of the femur and the plate connected to the lower end of the shaft member for the head and fixed along the outer surface of the femoral shaft can be changed. In the implant member connected via the connection shaft,
A screw hole is formed in the plate from the non-contact surface side toward the femoral shaft, and a male screw member that moves by a rotation operation from the non-contact surface side is screwed into the screw hole. The femoral head shaft member is fitted to the male screw member such that the angle formed by the head head shaft member with respect to the plate changes in conjunction with the movement of the male screw member. An implant member for treating a fracture. The male screw member has a concave portion in which a part thereof is cut out over the entire circumference, while the shaft member for a head has a convex portion at a lower end thereof, and the convex portion is slidable in the concave portion. The implant member for treating a femoral fracture according to claim 1, wherein the implant member is fitted.

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