JP2692922B2 - Bone fixation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a bone fixing device used as an orthopedic instrument for fixing a fracture or extending a bone.

[Conventional technology]

In general, in the case of a fracture or the like, a bone fixing device is used as a surgical instrument to fix a fracture, and the bone fixing device is telescopic and can be used to adjust the elongation of the bone. Can be used.

As such a bone fixing device, as shown in FIG. 10, an expandable and contractible main body 70 is provided, and an adjusting screw mechanism 73 is provided outside the main body 70, and the adjusting screw mechanism 73 has an adjusting knob.
74 are provided. At the left and right of the main body 70, a holding body 7
1, 72 are provided, and each holder 71, 72 has a pin support 75, 76.
Each of the pin supports 75, 76 holds a plurality of insertion pins 77,... 77 inserted into the bone 100.
The pin supports 75 and 76 for holding the insertion pin 77 and the holding bodies 71 and 72 for supporting the pin supports are connected by ball joins J and J, respectively, and the ball joint J is a fixing bolt b. Fixed by. Further, the expansion / contraction operation of the main body 70 is also fixed by the fixing bolts b, and the fixing bolts b, b, ... There is.

In such a fixing device, the fixing bolt b of the main body 70 is loosened, the adjusting knob 74 is rotated, and the adjusting screw mechanism 73 is expanded / contracted to adjust the gap between the holding bodies 71 and 72, and further, the holding bodies 71, 72. Loosen the fixing bolt b of the ball joint J
Is loosened to move the supports 75 and 76 to a desired position around the ball joint J, and thus the position of the insertion pin with respect to the bone 100 can be adjusted.

[Problems to be solved by the invention]

Although such a fixing device is used for fixing a fractured part or for extending the leg of a dwarfism patient, etc., such a fixing device is not provided with means for detecting the bone formation state of the fractured part, For example, when the fixing device is used for a bone fracture, after the fixing device is attached to the bone, the fixing device is generally kept as it is and the healing of the bone is left to the natural healing. In addition, it has been reported that bone formation is accelerated when a displacement stimulus due to expansion and contraction is applied to a fractured affected area at the time of a bone fracture, and such a bone fixing device can be used to apply the displacement stimulus. However, in the conventional fixing device,
The displacement stimulus is simply given by rotating the adjusting knob 74 and compressing the adjusting screw mechanism, and the magnitude of the displacement stimulus or its application timing cannot be controlled.

Further, in leg extension for dwarfism patients and the like, by adjusting the adjusting knob 74, it is possible to determine the extension amount and perform extension operation at constant time intervals,
In the conventional fixing device, the extension operation had to be performed without being able to grasp the bone formation state of the affected area. Furthermore, it is considered that the degree of bone growth is different at the start and completion of the bone extension, and the bone extension using such a device must rely on human intuition to perform excessive extension. On the contrary, the treatment period may be unnecessary and unnecessary. Also, if you perform an extension motion without being able to grasp the state of bone formation,
There is a problem in that the patient is distressed, or the growth of the affected tissue does not catch up with the bone extension, so that the complete bone extension cannot be achieved.

In view of the above points, the present invention can always grasp the formation or growth state of bone during the treatment of a fracture or the extension of the leg of a patient with dwarfism, etc. A displacement stimulus due to expansion and contraction can be applied to the affected area at a desired size or timing, and at the time of bone extension, the leg extension or displacement stimulus is automatically applied according to the state of bone formation. It is an object of the present invention to provide a bone fixing device capable of accelerating growth.

[Means for solving the problem]

Therefore, the present invention provides an expandable body, insertion pin holders provided on both sides of the body for holding pins to be inserted into bones, and the body attached to the body to automatically adjust the body to a desired length. And an actuator unit for elastically expanding and contracting. The actuator unit is configured to detect the expansion and contraction length of the main body and the shortening force applied from the bone.

[Action]

Insertion pin holders for holding insertion pins to be inserted into bones are provided on both sides of the expandable body, and an actuator unit is attached to the expandable body, and the actuator unit automatically adjusts the body to a desired length. The length of the bone is automatically detected, and the shortening force applied from both sides of the affected part of the bone is measured.

This makes it possible to apply displacement stimuli or extend bones while always grasping the state of bone formation.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 to 4, a bone fixing device M of the present invention is shown.
Has an operating part 1 for fixing bones and a control unit 2 connected to this operating part 1. The operating portion 1 has a telescopic main body 3, and a holding body mounting portion 3a is formed on the left side of the drawing in FIG. 2, and an insertion pin P to be inserted into a bone is formed on the side surface of the holding body mounting portion 3a. An insertion pin holder for holding the is attached. A slide cylinder 5 is slidably accommodated in the main body 3, and an expandable rod 10 is retractably accommodated in the slide cylinder 5. A holding body mounting portion 10a is provided on the outer end of the telescopic rod 10, and an insertion pin holding body 7 is provided on a side surface of the holding body mounting portion 10a. The insertion pin holding body 7 is a detachable detachable piece. 7a
And a support piece 7b provided on the holder attachment portion 10a side facing the attachment / detachment piece 7a. The insertion pin P is inserted and fixed between the attachment / detachment piece 7a and the support piece 7b. It has become. Further, the insertion pin holder 6 on the opposite side of the insertion pin holder 7 also has a detachable piece 6a and a support piece 6b provided so as to be opposed thereto, and the insertion pin P is provided between these two pieces 6a, 6b. To insert and hold.

As shown in FIG. 6, the insertion pin holders 6 and 7 have rotation shafts 60 and 60 extending in the lateral direction, and the rotation shaft 60 is inserted into the holder attachment portions 3a and 10a. The rotary shaft 60 is configured to be rotatable about its central axis (Y axis) and also rotatable about a vertical axis (Z axis).
The rotation around the Z axis is fixed by a screw 61, and the rotation around the Y axis is fixed by a screw 62 (Figs. 2 and 4). A connecting ring 8 is provided on the outer end of the slide cylinder 5.
2 is attached, and a slit 83 is formed in the vicinity of the connecting ring 82 in the circumferential direction of the slide cylinder 5 (FIG. 3). The connecting ring 82 is tightened by a tightening screw 81. By loosening the connecting ring 82, the telescopic rod 10 is rotated around the X axis which is the central axis of the main body, or the telescopic rod 10 is moved inside the slide tube 5. Can be inserted into the slide tube 5 or can be pulled out from the slide cylinder 5 by an appropriate length, and after the telescopic rod 10 is pulled out or rotated by a certain amount, the tightening screw 81 is tightened to move the insertion pin holder 7 to a desired position. Lock in position. Moreover, since the bone fixing position can be set independently in the X-, Y-, and Z-axis directions, the bone can be fixed stably.

An actuator unit 4 for allowing the main body 3 to expand and contract via a slide cylinder 5 is detachably attached to the main body 3. The actuator unit 4 is a telescopic mechanism T (Fig. 7) for expanding and contracting the slide cylinder 5.
A first storage cylinder 15 in which is stored, a second storage cylinder 16 provided adjacent to the first storage cylinder 15, and a connection cylinder 17 to which a cable C extending from the control unit is connected. There is. As shown in FIG. 7, a load cell 40 is provided at the tip of the first storage cylinder 15, and the load cell 40 faces the rear end of the reciprocating screw cylinder 30. The thread is cut, and the threaded part 13
a is in mesh. A spur gear 30a is formed on the outer peripheral surface of the rotating screw cylinder 30, and a worm 31 is meshed with the spur gear 30a. A block 14 is attached to the tip of the rotary screw rod 13 (FIG. 5), and a pin hook 12 projects from the block 14, and the pin hook 12 receives a connecting ring 82 fixed to the outer end of the slide cylinder 5. It is inserted in the hole 82a. The pin hook 12 is fixed in the receiving hole 82a by the screw 85.

In FIG. 7, the worm 31 is attached to a shaft 32, and the shaft 32 is provided with a bevel gear 33.
An encoder 38 is provided on a shaft 39 protruding outward from 33. Further, a bevel gear 34 meshes with the bevel gear 33, the bevel gear 34 is attached to a shaft 35, and the shaft 35 is connected to a motor 37 via a reduction gear 36. Therefore,
By rotating the motor 37, its rotational force is transmitted to the worm 31 via the bevel gears 34, 33, the rotation of the worm 31 causes the screw cylinder 30 to rotate, and the rotation of the screw cylinder 30 causes the screw cylinder 30 to rotate. Mating screw rod 13
Is reciprocally movable in the axial direction. The amount of rotation of the motor 37, that is, the length of the slide cylinder 5 extending from the main body 3 is detected by an encoder 38. Further, the reaction force, that is, the shortening force from the bone to be treated is transmitted to the screw cylinder 30 via the rotary screw rod 13, and the axial force applied to the screw cylinder 30 is applied to the load cell 40.
Ensures that the shortening or half force exerted by the bone to be treated is measured.

The actuator unit 4 is detachably attached to the outer periphery of the main body 3 by a band 20,
As shown in FIG. 5, 20 is composed of a first band piece 20c and a second band piece 20d, and these two band pieces 20c, 20d are detachable by a ring 21 at the tip thereof. 20c is hinged to the body of the actuator unit at position 20a, and
The band piece 20d is hinged at the position 20b.

The bone anchoring device M of the present invention is formed as a portable type, and the control unit 2 has a box 50 which can be hung from the shoulder by an operator by a band 90 (No. 1). 1
Figure). An indicator 54 is provided on the upper surface of the box 50 for displaying the amount of expansion and contraction of the main body 3 and the shortening force, that is, the reaction force applied from the bone, and a setting unit 53 is provided next to the indicator 54. The setting unit 53 sets the expansion / contraction amount of the main body 3, the timing of the displacement stimulus applying operation, and the magnitude amount of the displacement stimulus. Two batteries 51, 52 are provided in the box 50, and the battery 51 is the slide cylinder 5
The battery 52 serves as a power source for the display 54, the setting unit 53, etc.

 Next, the operation of the bone fixing device of the present invention will be described.

When the insertion pin P is inserted into the bone by widening the gap between the insertion positions on both sides of the affected part of the bone, the tightening screw 81 of the connecting ring 82 attached to the outer end of the slide tube 5 is loosened and the telescopic rod 10 is inserted.
Is pulled out to an appropriate position, and the telescopic rod 10 is rotated to a predetermined position around the X-axis so that the insertion pin holder 7 is moved to a desired position.
Position and tighten the tightening screw 81 at that position. After that, the setting unit 53 sets the amount of expansion and contraction of the main body 3, that is, the distance that the slide cylinder 5 extends, and the timing when the displacement stimulus is given to the affected part of the bone at regular intervals. The mode for applying the displacement stimulus in the treatment of fractures or fractures in patients with dwarfism, etc., differs depending on the patient, and the leg extension speed displacement stimulation amount (stretch amount), number of stimulations, cycle, displacement pattern, etc. While reading the shortening force or half force applied from the bone and the expansion / contraction amount of the main body, that is, the expansion / contraction amount of the bone from the display 54, the treatment according to each patient is performed.

In the course of leg extension and fracture treatment of dwarfism patients, displacement stimulus is applied as shown in FIG. That is, the shortening force with respect to the treatment period has a relationship as shown by the curve A, and the shortening force applied from the bone is small because the affected part of the bone becomes solid as the treatment period elapses.
When displacement stimulus is applied to the affected area by contracting the slide cylinder 5 at each position a, b, c, d in the treatment period,
As the treatment period decreases, the bone becomes stiff and the repulsive force received from the bone increases and the amount of fluctuation increases.

As described above, in the bone fixing device of the present invention, displacement stimuli can be automatically given at regular intervals, and the shortening force, that is, the reaction force applied from the bone is measured to quantitatively determine the bone formation state. It can be accurately grasped, and the bone formation can be significantly accelerated by applying the displacement stimulus to the bone appropriately.

Further, in the bone constructing device of the present invention, the main body 3
Since the axis of the extension mechanism T for applying a driving force for extending and retracting the insertion pin P and the position of the insertion pin P held by the insertion pin holders 6 and 7 substantially coincide with each other, the insertion pin when the extension mechanism T is operated. It is possible to avoid a bending moment acting on the moving mechanism 12 due to the repulsive force applied from the bone via P, so that the expanding and contracting mechanism T can operate smoothly. Further, in the bone fixing device of the present invention, the insertion pin holders 6 are provided on both sides of the main body 3, and the insertion pin holders 6 and 7 are provided.
Since it can be stably tightened and fixed to the side surface of the bone and the fixing positions of the bones can be independently performed in the X, Y and Z axis directions, the ball joint J in the conventional bone fixing device as shown in FIG. Inserted by pin support 76
As it supports the bone, the bone can be firmly and stably fixed and the bone can be stably corrected.
Further, the main body 3 can be set in two stages, that is, two stages of the slide cylinder 5 and the telescopic rod 10, so that the telescopic length can be set to be long, and a wide interval between the insertion pins P to be inserted on the left and right of the affected part of the bone can be secured. Further, since the actuator unit 4 is detachable from the main body 3, an extension screw which can be manually operated after the actuator unit 4 is detached from the main body 3 is attached to the connecting ring 82 to manually expand and contract the main body. It is also possible.

The slide cylinder 5 is locked by a lock screw 22 as shown in FIG. 4, and a terminal 55 is provided on the side surface of the box 50 of the control unit 2 shown in FIG. It is connected to a memory meter or the like for storing the force or the amount of expansion and contraction. Further, the setting unit 53 of the control unit 2 inputs a program for an arbitrary one of, for example, a sine wave or a triangular wave as a displacement stimulation pattern, and the main body 3 expands and contracts according to the program.

Further, in the bone fixing device of the present invention, as shown in FIG. 9 (b), the curved bone B as shown in FIG. 9 (a) has two insertion pin holders 6, 7 in the Y-axis. It is also possible to rotate it around and straighten it. At this time, since the insertion pin holders 6 and 7 can rotate independently around each axis, they are safe unlike those free about all axes.

〔The invention's effect〕

Since the present invention is configured as described above, there is an effect that it is possible to constantly grasp the formation state of the affected area of the bone and to extend the leg or treat the bone at the time of fracture according to the formation state.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a bone fixing device of the present invention, FIG. 2 is a plan view of an operating portion of the bone fixing device of the present invention, and FIG. 3 is a plan view when the operating portion of the bone fixing device is extended. 4 and 5 are side views of the operating portion, FIG. 5 is a configuration diagram of a band for attaching the control unit to the main body, FIG. 6 is an explanatory view of the action of the insertion pin holder, and FIG. 8 is a configuration diagram of the mechanism provided, FIG. 8 is a graph for explaining the relationship between the treatment period and the shortening force received from the bone, FIG. 9 (a),
(B) is an explanatory view of the operation when the bone fixing device of the present invention is used to correct the bone, and FIG. 10 is a plan view of a conventional bone fixing device. 1 ...... actuator, 2 ... control unit, 3 ... main body, 4 ... actuator unit, 5 ... slide tube, 6,7 ... insertion pin holder, 10 ... extendable rod, 40 ... load cell, 82 …… Connection ring.

Claims (4)

(57) [Claims] 1. An expandable and contractible main body, insertion pin holders provided on both sides of the main body for holding pins to be inserted into a bone, and the main body attached to the main body to automatically adjust the main body to a desired length. A bone fixing device, comprising: an actuator unit for expanding and contracting, and the actuator unit detects an expansion and contraction length of a main body and a shortening force applied from bone. 2. The bone fixing device according to claim 1, wherein the actuator unit is detachably attached to the main body. 3. The bone fixing device according to claim 1, wherein the actuator unit includes a load cell, and the shortening force of the bone is measured by the load cell. 4. The actuator unit is connected to a control unit, the actuator unit is controlled by the control unit, and the amount of expansion and contraction of the main body and the shortening force of the bone are displayed on the control unit. Claim 1
4. The bone fixing device according to any one of 1 to 3.