JPH02180254A - Fixing device for bone - Google Patents

Abstract

PURPOSE:To automatically extend the leg or give displacement stimulus to a bone to quicken the growth of the bone by providing an actuator unit for automatically expanding and contracting a main body to a desired length, which is fixed to the expansible main body. CONSTITUTION:A fixing device M for the bone has an actuating portion 1 for fixing the bone and a control unit 2. An actuator unit 4 for freely expanding and contracting a main body 3 through a slide cylinder 5 is removably fitted to the main body 3. The actuator unit 4 stores an expansion mechanism T for expanding and contracting the slide cylinder 5. By loosening a coupling ring 82, an expansion rod 10 can be turned round X-axis which is the central shaft of the main body 10 or the expansion rod 10 can be inserted in the slide cylinder 5 or drawn out of the slide cylinder 5 to a suitable length. Furthermore, the fixing position of the bone can be set in the directions of X, Y and Z independently so as to stably fix the bone.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fracture fixation device used as an orthopedic instrument for fixing a fracture or lengthening a bone.

[Conventional technology]

Generally, in the case of a fracture, a bone fixation device is used as a surgical instrument to fix the fractured part, and this bone fixation device is expandable and can be used to adjust the elongation of the bone. It can be used.

As shown in FIG. 10, such a bone fixation device has a telescopic main body 70 H, and an adjusting screw mechanism IN 73 is provided on the outside of the main body 70, and this adjusting screw mechanism 73 includes: An I adjustment knob 74 is provided. Holding bodies 71 and 72 are provided on the left and right sides of the main body 70, and each holding body 71
．． 72 are provided with pin supports 75 and 76, respectively, and each of the pin supports 75 and 76 holds a plurality of insertion pins 77, . . . , 77 to be inserted into the ft100.

Pin support 75°7 for holding the insertion pin 77
6 and holders 71 and 72 for supporting the pin support are connected by pole joints J and J, respectively,
This ball joint J is fixed by a fixing bolt b. Further, the main body 70 is fixed by a fixing bolt b from the expansion/contraction movement, and the fixing bolts b, b are also attached to the support t11 body 75 and 76.

The state of tightening of the insertion pin 77 is adjusted by b.

In such a fixing device, the fixing bolt b of the main body 70 is loosened and the adjusting knob 74 is rotated to open the adjusting screw mechanism 73.
Adjust the gap between the holding bodies 71 and 72 by expanding and contracting the holding bodies 71 and 72, and then loosen the fixing bolts b of the holding bodies 71 and 72 to loosen the ball joint J. It is possible to move the insertion pin to a desired position and thus adjust the position of the insertion pin relative to the bone 100.

[Problem to be solved by the invention]

Such fixation devices are used to fix fractured parts and to lengthen the legs of patients with dwarfism, but such fixation devices are not equipped with means for detecting the state of bone formation in the fractured part. For example, when a fixation device is used for a fracture, one end of the fixation device is generally left in place after it is attached to the bone, allowing the bone to heal naturally. Furthermore, it has been reported that when a fracture occurs, bone formation is accelerated by applying displacement stimulation by stretching to the affected part of the fracture, and such a bone fixing device can be used to apply this displacement stimulation. However, in conventional fixation devices,
Displacement stimulation is only applied by simply rotating the adjustment knob 74 to compress the adjustment screw (R), and the magnitude of this displacement stimulation or the timing at which it is applied cannot be controlled.

In addition, regarding leg lengthening for patients with dwarfism, etc.,
It is possible to set the extension 1 by adjusting the adjustment knob 74 and perform the extension operation at regular time intervals, but with conventional fixation devices, the extension operation cannot be performed without knowing the state of formation of the affected area 11. had to be done. Furthermore, it is thought that the degree of bone growth differs between the beginning and the end of lengthening, and bone growth using such a device may result in excessive lengthening that requires relying on human intuition. On the contrary, the treatment period may be spent unnecessarily. Furthermore, if the lengthening operation is performed without knowing the state of bone formation, it may cause pain to the patient, and furthermore, the growth of the affected tissue may not be able to keep up with the growth of the bone, making it impossible to achieve complete lengthening. Ta.

In view of the above, the present invention has been developed so that when treating a fracture or lengthening the legs of a patient with dwarfism, it is possible to grasp the injury formation or growth part at all times, and the In the event of a fracture, displacement stimulation by expansion and contraction can be applied to the affected part of the fracture at the desired magnitude or timing, and during bone growth, the leg can be automatically lengthened according to the state of bone formation. 14. Displacement stimulation. The purpose of the present invention is to provide a 1'1 fixation device that can speed up bone growth by increasing bone growth.

[Failure to solve the problem]

SUMMARY OF THE INVENTION Therefore, the present invention provides a telescopic main body, an insertion pin holder provided on both sides of the main body for holding a pin to be inserted into a bone, and an insertion pin holder attached to the main body to automatically adjust the main body to a desired length. This actuator unit has an actuator unit for expanding and contracting.・When detecting the expansion/contraction length of the main body, it also detects the shortening force applied from the bottom.

[Function] Insertion pin holders for holding insertion pins inserted into the bone are provided on both sides of the telescopic main body, an actuator unit is attached to the telescopic main body, and the main body is moved to a desired length by this actuator unit. The bone is automatically expanded and contracted, and the length of the expansion and contraction is automatically detected, and the shortening force applied from both sides of the affected part of the bone is determined by 71-1.

This makes it possible to apply displacement stimulation or perform bone growth while constantly monitoring the state of bone formation.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

1 to 4, a bone fixation device M according to the present invention has an operating section 1 for fixing a bone, and a control unit 2 connected to this operating section 1. As shown in FIGS. The actuating part 1 has a main body 3 which is extendable and retractable, and a holding body mounting part 3a is formed on the left side of the figure in FIG. An insertion pin holder is attached to hold the The main body 3
A slide tube 5 is slidably housed inside the slide tube 5, and an extendable rod 1o is accommodated in the slide tube 5 so as to be freely extendable and retractable. A holder attachment part 10a is provided at the outer end of the telescopic rod 1o, and an insertion pin holder 7 is provided on the side surface of this holder attachment part 10a. 7a, and a support piece 7b provided on the side of the holder attachment part 10a opposite to the detachable piece 7a, and the insertion pin P is inserted and fixed between the detachable piece 7a and the support piece 7b. It looks like this. 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 opposite thereto, and an insertion pin P is inserted and held between these pieces 6a and 6b.

The insertion pin holder 6.7 is, as shown in FIG.
What are the rotating shafts 60 and 60 that extend in the direction of the seedlings? Inserted into Oa. The rotating shaft 60 is configured to be able to rotate around its central axis (Y axis) and also around 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 (Fig. 2.4). A connecting ring 82 is attached to the outer end of the slide tube 5, and a slit 83 is formed in the vicinity of the connecting ring 82 in the circumferential direction of the slide tube 5 (FIG. 3). The connecting ring 82 is tightened by a tightening screw 81, and by loosening the connecting ring 82, the telescopic rod 10 can be rotated around the X axis, which is the central axis of the main body, or the telescopic rod 10 can be moved into the slide cylinder 5. The telescopic rod 10 can be inserted into the slide tube 5 or pulled out to an appropriate length from the slide tube 5.
After pulling out or rotating a certain amount, the tightening screw 81
is tightened to fix the insertion pin holder 7 at a desired position. Moreover, the fixed position of the bone is X.

Since the settings can be made independently in the Y and Z axis directions, bones can be stably fixed.

An actuator unit 4 is detachably attached to the main body 3 to make the main body 3 extendable and retractable via a slide tube 5. The actuator unit 4 is a telescoping machine tMT for expanding and contracting the slide tube 5 (FIG. 7).
A first storage tube 15 in which is housed, a second storage tube 16 provided adjacent to the first storage tube 15, and a connection tube 1 to which a cable C extending from the control unit is connected.
7 and have sex. As shown in FIG. 7, a load cell 40 is provided at the tip of the first storage tube 15, and this load cell 40 faces the rear end of the screw tube 30 that can reciprocate. is threaded, and the threaded portion 13a of the rotating threaded rod 13 meshes with this thread. A spur gear 30a is formed on the outer circumferential surface of the rotating threaded cylinder 30, and a worm 31 meshes with the spur gear 30a. A block 14 is attached to the tip of the rotating screw 13 (
5), a pin hook 12 protrudes from this block 14, and this pin hook 12 is inserted into a receiving hole 82a of a connecting ring 82 fixed to the outer end of the slide cylinder 5. This pin hook 12 is fixed within the receiver 82a by a spring 85.

In FIG. 7, the worm 31 is attached to a shaft 32, a bevel gear 33 is provided on the shaft 32, and an encoder 38 is mounted on a shaft 39 projecting outward from the bevel gear 33.
is provided. Further, a bevel gear 34 meshes with the bevel gear 33, this bevel gear 34 is attached to a shaft 35, and this 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, and the rotation of the worm 31 rotates the threaded barrel 30. A rotary tightening rod 13 screwed therein is capable of reciprocating 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. In addition, the reaction force from the bone to be treated, that is, the shortening force, is transmitted to the threaded cylinder 30 via the rotating threaded rod 13, and the axial force applied to this threaded cylinder 30 is applied to the load cell 40.
The shortening force or small force exerted by the bone to be treated is measured by 0.

The front actuator unit 4 is detachably attached to the outer periphery of the main body 3 by a band 20, and the band 20 is made up of a first band piece 20c and a second band piece 20d, as shown in FIG. So, these two band pieces 2
0c and 20d are detachably attached at their tips by a ring 21, the first band piece 20c is hinged to the main body of the actuator unit at a position 20a, and the second band piece 20d is hinged to a position 20b. There is.

The bone fixation device M according to the invention is constructed in a portable form, the control unit 2 having a box 50 which can be hung from the operator's shoulder by means of a band 90. (Figure 1) A display 54 is provided on the top surface of the box 50 to display the amount of expansion and contraction of the main body 3 and the shortening force, that is, the reaction force applied from the main body 3. Next to this display 54 is a setting section 5.
3 is provided, and this setting section 53 sets the amount of expansion and contraction of the main body 3 or the timing of the application operation of the displacement stimulus and the magnitude of the displacement stimulus. Previous 5 members box 50 (
Here, two batteries 51 and 52 are provided, and battery 5
Reference numeral 1 serves as a driving source for the telescoping mechanism T for extending and retracting the slide tube 5, and the battery 52 serves as a power source for the display 54, the setting section 53, and the like.

Next, the operation of the bone fixation device of the present invention will be explained.

- When inserting the insertion pin P into the bone by widening the interval between the insertion positions on both sides of the injured part, loosen the tightening screw 81 of the connecting ring 82 attached to the outer end of the slide cylinder 5 and remove the telescopic rod. 10 to an appropriate position and X? Rotate the telescopic rod 10 to a predetermined position around To to position the insertion pin holder 7 at a desired position, and tighten the tightening screw 8 at that position.
Tighten 1.

Thereafter, the setting section 53 sets the amount of expansion and contraction of the main body 3, that is, the distance that the slide tube 5 extends, and also sets the timing when applying displacement stimulation to the affected part of the bone at regular intervals. The speed of leg extension in patients with dwarfism or the mode of applying displacement stimulation in the treatment of fractures differs for each patient, and the leg extension speed, displacement stimulation 1i (extension/contraction It), number of stimulations, period, displacement pattern, etc. The shortening force applied from the wound, that is, the small force, and the amount of expansion and contraction of the main body, that is, the amount of expansion and contraction of the bone, are read from the display 54 while performing treatment according to each patient.

In the course of leg lengthening and fracture treatment for dwarfism patients, displacement stimulation is applied in the form shown in FIG. 8. That is, the shortening force with respect to the treatment period has a relationship as shown by curve A, and as the treatment period becomes more suitable, the affected part of the bone becomes harder, so the shortening force applied by the bone becomes smaller.
When displacement stimulation is applied to the affected area by contracting the slide tube 5 at each position a, b, c, and d during the treatment period, as the treatment period decreases, the bone hardens.
The repulsive force received from ′+ increases and the amount of its fluctuation increases.

As described above, in the bone fixation device of the present invention, displacement stimulation can be automatically applied at regular intervals, and the shortening force, that is, the reaction force applied from the bone can be reduced to 1l11.
By determining this, the state of bone formation can be quantitatively and accurately grasped, and furthermore, by appropriately applying displacement stimulation to the bone, bone formation can be significantly accelerated.

Furthermore, in the bone structuring device of the present invention, the axis of the telescoping machine tMT for applying a driving force for expanding and contracting the main body 3 and the position of the insertion pin P held by the insertion pin holder 6.7, are almost the same, so the telescoping machine tM
When operating T, it is possible to avoid a bending moment acting on the moving machine 1M12 due to the repulsive force applied from the bone via the insertion pin P, and therefore the telescoping mechanism T can operate smoothly. Furthermore, in the bone fixation device of the present invention, the insertion pin holders 6 are stably fastened and fixed to the sides of the insertion pin holders 6.7 on both sides of the main body 3, and the blue fixation positions are X, Since it can be performed independently in the Y and Z axis directions, the insertion pin support 76 is supported by the ball joint J in the conventional bone fixation device as shown in FIG. 10, and the bone is firmly stabilized. It can be fixed and bone correction can be performed stably. Further, the main body 3 can be extended in length by having two stages, that is, the slide tube 5 and the telescopic rod 10, and a wide interval between the insertion pins P inserted on the left and right sides of the affected part of the bone can be secured. Further, since the actuator unit 4 is detachable from the main body 3, after the actuator unit 4 is removed from the main body 3, an extension screw that can be manually operated is attached to the connecting ring 82, and the main body can be manually extended or contracted. It is also possible.

The slide tube 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 1 etc. for storing the shortening force or expansion/contraction m. Furthermore, the setting section 53 of the control unit 2 manually programs any one of the displacement stimulation patterns, such as a sine wave or a triangular wave, and the main body 3 expands and contracts in accordance with the program.

Moreover, the fixation device of 17. of the present invention fixes the curved bone B as shown in FIG. 9(a), as shown in FIG. 9(b).
It is also possible to rotate the two insertion pin holders 6 and 7 around the Y axis to straighten them. At this time, since the insertion pin holders 6 and 7 can rotate independently around each axis, it is safe unlike the case where the insertion pin holders are free to rotate around all the axes.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to constantly grasp the formation condition of the bone in the affected area and to extend the leg or treat the bone at the time of fracture according to the formation condition and deafness. play.

Graph for explaining the relationship between shortening forces, Figure 9 (a)
(b) is an explanatory view of the operation when bone correction is performed using the bone fixing device of the present invention, and FIG. 10 is a plan view of the conventional bone fixing device.

1... Actuation part, 2... Control unit, 3.
... Main body, 4. Actuator unit, 5. Slide tube, 6.7. Insertion pin holder, 10. Telescopic rod, 40. Load cell, 82. Connection ring.

[Brief Description of the Drawings] Fig. 1 is a block diagram of the bone fixation device of the present invention, Fig. 2 is a plan view of the operating section of the bone fixation device of the present invention, and Fig. 3 is the operation of the bone fixation device. Fig. 4 is a side view of the actuating part, Fig. 5 is a configuration diagram of the band for attaching the control unit to the main body, Fig. 6 is an explanatory diagram of the operation of the insertion pin holder, Fig. Figure 7 is a configuration diagram of the mechanism provided in the actuator unit, and Figure 8 is the treatment period and the applicant's representative's treatment period (a). O times

Claims (4)

[Claims] 1. a telescopic main body; insertion pin holders provided on both sides of the main body for holding pins to be inserted into the bone; An actuator unit, the actuator unit detecting the length of expansion and contraction of the main body as well as the shortening force applied from the bone. 2. The bone fixation device according to claim 1, wherein the actuator unit is detachably attached to the main body. 3. The actuator unit includes a load cell,
3. The bone fixation device according to claim 1, wherein the bone shortening force is measured by the load cell. 4. The actuator unit is connected to a control unit, and the actuator unit is controlled by the control unit, and the control unit displays the amount of expansion and contraction of the main body and the shortening force of the bone. The bone fixation device according to any one of.