JP2007061154A - Bone drilling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide bone drilling instrument capable of easily recovering shaven bones and performing quick and appropriate treatment when providing a base hole on the bone. <P>SOLUTION: The bone drilling instrument for providing the base hole beforehand so as to insert an osteosynthesis implant into the bone comprises: a cylindrical main body part 2 provided with a void part 9 in the inside; a blade part 7 provided on the distal end of the main body part 2; and a friction reduction means for reducing friction between the outer surface 18 of the bone shaven by the blade part 7 and taken into the void part 9 and the inner surface 26 of the main body part 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bone drilling instrument for opening a pilot hole in advance in order to facilitate insertion of an osteosynthesis implant into bone in the treatment of various fractures.

In recent years, for the treatment of fractures and the like, it has been practiced to fix and reinforce the fractured part by inserting an osteosynthesis implant into the bone and fixing it in the inserted state.
For example, when taking a femoral neck fracture, insertion of an osteosynthesis implant for fixing the fracture is generally performed as follows (for example, see Non-Patent Document 1). . That is, as shown in FIG. 7A, the skin near the upper part of the diaphysis 102 is incised from the side of the human body, and the angle guide 103 is inserted from the side through the incision into a predetermined position on the upper part of the diaphysis 102. Install in. From this state, while observing the X-ray irradiation image, while rotating the guide pin 104 having a male screw portion at the distal end from the insertion hole 103a of the angle guide 103 by a hand drill or the like, a predetermined inside of the bone head 105 is obtained. Screw into position.

  Next, the angle guide 103 is removed while the guide pin 104 is inserted. Then, as shown in FIG. 7B, a cylindrical drill blade 112 having a blade portion extending spirally over the entire length in the length direction is passed through the guide pin 104 that is still in the bone. In this state, the drill main body (not shown) is driven to rotate the drill blade 112. Then, drilling is performed until the tip of the drill blade 112 reaches a predetermined position in the bone head 105, whereby a pilot hole is provided around the guide pin 104. Then, the drill blade 112 is removed while the guide pin 104 is inserted.

  Further, as shown in FIG. 7C, a lag screw 107 having a male screw portion at the tip is passed through a shaft support hole 106 a of a tube plate 106 for fixing to the side of the diaphysis 102. The lag screw 107 has a larger diameter than the guide pin 104 and is formed in a cylindrical shape so that the guide pin 104 can be passed through the lag screw 107. The tube plate 106 includes a substantially plate-like main body portion 106c and a shaft support portion 106b that supports the guide pin 104. An angle at which the extending direction of the main body portion 106c and the extending direction of the shaft support portion 106b intersect. For example, θ is set to 135 degrees and 145 degrees in advance.

  Next, the rear end portion of the guide pin 104 that is still in the bone is passed through the insertion hole at the front end of the lag screw 107, and the lag screw 107 is pushed forward in the direction of the front end of the guide pin 104. Further, using the wrench 108, the lag screw 107 is screwed along the pilot hole until the tip reaches a predetermined position in the bone head 105. Then, the guide pin 104 is removed while the lag screw 107 is screwed.

Next, as shown in FIG. 7 (d), using the impactor 109 as a pushing tool, the shaft support part 106 b of the tube plate 106 is inserted into the bone, and the main body part 106 c comes into close contact with the diaphyseal part 102. Until the tube plate 106 is pushed in. In this state, as shown in FIG. 7 (e), the screw 110 is inserted into the predetermined mounting hole and the shaft support hole 106 a of the main body portion 106 c to firmly fix the tube plate 106 and the lag screw 107. Finally, the incised skin is sutured to complete a series of treatments.
According to these treatments, the bone head 105 is fixed and reinforced to the diaphysis 102, and the fracture can be appropriately joined.

Here, in the case of a femoral neck fracture, the bone head 105 may be displaced toward the diaphysis 102 side. In this case, before the series of treatments, it is necessary to return the bone head 105 to an appropriate position to eliminate the deviation. However, when the bone head 105 is displaced toward the diaphysis 102, the diaphysis 102 may be partially collapsed by the bone head 105. Therefore, when the bone head 105 is returned to an appropriate position, a bone defect 110 having a low bone density is generated in a portion of the diaphyseal portion 102 where the bone head 105 is displaced. When the bone defect 110 is generated, the strength of the bone is lowered. Therefore, it is necessary to reinforce the bone defect 110 by filling the bone defect 110 with a bone fragment or a paste.
At this time, since it is preferable to use the patient's own bone as the bone fragment to be inserted into the bone defect 110, the patient's own bone is collected during the treatment of the femoral neck fracture. There is a request to be made. Therefore, as shown in FIG. 7B, it is conceivable to collect the shaved bone when drilling the prepared hole using the drill blade 112.

However, since the drill blade 112 as described above is provided with a blade portion over the entire length of its side surface, when the bone is cut, the bone is crushed and becomes powdery. Therefore, the bone defect 110 cannot be effectively reinforced.
Therefore, it is conceivable to provide the blade part at the tip so that the shaved bone is taken into the internal cavity as a bone piece and the bone piece is recovered.
Noas Medical Co., Ltd. Noas Hip Screw, Catalog p. 6

  However, in such a configuration, although bone is taken into the internal cavity, the bone expands slightly when taken out to the outside, so that the taken-in bone is fixed to the inner surface of the cavity. . And since it will adhere in that way, it will take much time and effort to take out the bone taken into the cavity from the cavity.

  The present invention has been made to solve such a problem, and when a pilot hole is provided in a bone, the shaved bone can be easily recovered as a bone fragment and can be quickly and appropriately treated. An object is to provide a bone drilling instrument.

In order to solve the above problems, the present invention provides the following means.
The invention according to claim 1 is a bone drilling instrument for providing a pilot hole in advance in order to insert an osteosynthesis implant into a bone, a cylindrical main body having a hollow portion therein, and the main body And a friction reducing means for reducing friction between the outer surface of the bone cut into the cavity by the blade and the inner surface of the main body. It is characterized by.

In the bone drilling instrument according to the present invention, when the blade is brought into contact with the portion where the pilot hole is provided and the bone is cut, the bone is taken into the cavity of the main body. And the friction between the outer surface of the taken-in bone and the inner surface of a main-body part is reduced by a friction reduction means.
Thereby, the bone taken in in the cavity part can be taken out easily.

  According to a second aspect of the present invention, in the bone drilling device according to the first aspect, the friction reducing means includes a mechanism that allows the taken-in bone to expand.

In the bone drilling device according to the present invention, when the bone is taken into the cavity, the bone tries to expand in the radial direction and tries to apply radial pressure to the inner surface of the main body. Directional expansion is allowed. Therefore, the friction between the outer surface of the taken-in bone and the inner surface of the main body is reduced.
Thereby, a bone can be easily taken out from the cavity.

  The invention according to claim 3 is the bone drilling instrument according to claim 2, wherein the mechanism is configured such that an inner diameter of the blade portion is smaller than an inner diameter of the main body portion. .

In the bone drilling instrument according to the present invention, since the inner diameter of the blade portion is smaller than the inner diameter of the main body portion, the outer diameter of the bone shaved by the blade portion is smaller than the inner diameter of the main body portion. Become. Therefore, the radial expansion of the bone taken into the cavity is allowed, and the bone is prevented from being firmly fixed to the inner surface of the main body.
Thereby, the friction between the outer surface of the taken-in bone and the inner surface of the main body is reduced, and the bone taken into the cavity can be easily taken out from the main body.

  According to a fourth aspect of the present invention, in the bone drilling instrument according to the second aspect, the mechanism includes a groove formed on an inner surface of the main body portion and extending along a length direction of the main body portion. It is characterized by being configured.

In the bone drilling device according to the present invention, when the bone is taken into the cavity, the expansion is allowed by the groove. As a result, the entire pressure on the inner surface of the main body is relieved, and the friction between the captured bone outer surface and the inner surface of the main body is reduced.
Thereby, the same effect as that of the invention according to claim 3 can be obtained.

  According to a fifth aspect of the present invention, in the bone drilling instrument according to the first to fourth aspects, the friction increases the friction between the outer surface of the bone shaved by the blade portion and the inner surface of the blade portion. An increase means is provided.

In the bone drilling instrument according to the present invention, the friction between the outer surface of the bone shaved by the blade and the inner surface of the blade is increased by the friction increasing means.
Here, in order to recover the bone fragment in a state where the bone fragment is cut and the bone fragment is taken into the cavity, it is necessary to finally separate the bone fragment from the bone body. However, even if the main body is simply pulled out of the bone main body, the bone fragments remain without being separated from the bone main body.
In the present invention, since the friction between the outer surface of the cut bone and the inner surface of the blade portion increases, if the main body is pulled while the bone fragment is taken into the cavity portion, the friction will be the same as the bone fragment. Directional force works.
Thereby, the bone piece in the state taken in in the cavity part can be easily separated from the bone body simply by pulling out the main body part, and the bone piece can be quickly recovered.

  The invention according to claim 6 is the bone drilling device according to claim 5, wherein the friction increasing means is a female screw formed on the inner surface of the blade portion.

In the bone drilling instrument according to the present invention, when the bone is cut by bringing the blade portion into contact with each other, a screw is cut on the outer surface of the cut bone by the female screw. Therefore, the friction between the outer surface of the shaved bone and the inner surface of the blade portion increases.
Thereby, the bone taken into the cavity can be recovered quickly and easily.

  According to the present invention, a bone fragment taken into a cavity can be easily taken out, and a quick and appropriate treatment can be performed without using an artificial bone or the like.

Example 1
Hereinafter, a bone drilling instrument according to a first embodiment of the present invention will be described with reference to the drawings.
1 to 3 are explanatory views showing an example in which the present invention is applied to a bone drilling drill.
1 to 3, reference numeral 1 denotes a bone drill.
The bone drilling drill 1 includes a cylindrical main body 2 having a hollow portion 9 therein, and both ends in the length direction thereof are open. The outer surface of the main body 2 is mirror-finished for easy insertion into the bone. An attachment portion 3 for attaching to a drill body (not shown) is provided at the base end portion of the body portion 2. An engaging notch 4 is formed in the mounting portion 3, and the engaging notch 4 is adapted to engage with a protrusion provided on the drill body.

  On the other hand, a tip 7 (tip) 6 of the main body 2 is provided with a blade 7 around an opening 10 communicating with the cavity 9. The blade portion 7 includes a digging blade 12 that excavates bone, and a support wall portion 13 that supports the digging blade 12. The excavation blade 12 is formed on the side portion of the support wall portion 13 so as to be directed in the circumferential direction of the main body portion 2. Further, the outer surface of the support wall portion 13 and the outer surface of the main body portion 2 are formed flush with each other. The main body 2, the support wall 13 and the excavation blade 12 are integrally formed, and the outer diameter is set to the same dimension over the entire length of the main body 2 and the support wall 13.

  Under such a configuration, by engaging the engagement notch 4 with the projection of the drill body, the bone drill 1 is detachably attached to the drill body. Then, the blade body 7 is rotated by driving the drill body and rotating the drill 1 for drilling. Further, by pressing the excavating blade 12 against the bone while the blade portion 7 is rotated, the bone is excavated so that the bone becomes a columnar shape and is taken into the hollow portion 9 from the opening 10. Yes.

Furthermore, in the drill 1 for drilling in the present embodiment, as shown in FIG. 3, the inner diameter φ1 of the blade portion 7 is set smaller than the inner diameter φ2 of the main body portion 2, and the inner surface (inner surface) 26 of the main body portion and A rising wall portion 15 is formed between the blade portion inner surface (inner surface) 27.
For example, in this embodiment, the total length of the bone drilling drill 1 is set to 145.8 mm, the inner diameter φ1 is 6.5 mm, the inner diameter φ2 is 7.5 mm, and the height of the rising wall portion 15 is 0.5 mm. Is set to

Under such a configuration, when the drill body is driven and the bone cut into the hollow portion 9 is taken in from the opening 10, the outer surface 18 of the columnar taking-in bone 17 and the inner surface 26 of the main body portion are obtained. A clearance d corresponding to the height dimension of the rising wall 15 is generated between the two. By this clearance d, expansion of the capturing bone 17 in the radial direction (direction orthogonal to the length direction of the main body 2), that is, radially outward is allowed. The clearance d is set so that the outer surface 18 and the main body inner surface 26 do not come into contact with each other even when the capturing bone 17 expands radially outward.
The above configuration in which the inner diameter φ1 is set smaller than the inner diameter φ2 and the clearance d is set between the outer surface 18 and the main body inner surface 26 constitutes a mechanism that allows the bone to expand in the radial direction. is there. And the mechanism comprises the friction reduction means which reduces the friction of the length direction of the main-body part 2 between the outer surface 18 and the main-body part inner surface 26. FIG.

Next, the action of the bone drill 1 in this embodiment configured as described above will be described in accordance with, for example, treatment of a femoral neck fracture.
In general, in the case of a femoral neck fracture, as described above, an osteosynthesis implant such as a lag screw is inserted and fixed in the bone head 21 shown in FIG. The treatment of fixing and joining to the upper part is performed. Therefore, in order to insert the lag screw into the bone head 21 quickly and accurately, the guide pin 24 is inserted at an appropriate position and angle, and a pilot hole for inserting the lag screw is provided along the guide pin 24. Need to be prepared in advance. Moreover, when the bone head 21 is returned to an appropriate position to eliminate the deviation, a bone defect 23 may occur. In order to eliminate the decrease in strength due to the bone defect 23, it is necessary to fill the bone defect 23 with a bone fragment to improve the bone density.
These bone fragments are preferably the patient's own rather than the artificial bone.
Therefore, if the prepared bone can be collected as a bone fragment when the prepared hole is provided, the patient's own bone fragment can be put into the bone defect 23.

In the bone drill 1 for drilling bone according to the present embodiment, the bone cut when drilling the pilot hole is easily collected as a bone fragment as follows. Since the procedure until the guide pin 24 is inserted is as described above, it is assumed here that the guide pin 24 is inserted at an appropriate position and angle.
First, the engagement notch 4 is engaged with the protrusion of the drill body, and the bone drill 1 is attached to the drill body. Then, the rear end of the guide pin 24 is inserted into the cavity 9 from the opening 10. In this inserted state, the drill body 1 is driven to rotate the bone drilling drill 1. Then, the bone drilling drill 1 is pushed forward along the guide pin 24 to the front of the diaphysis 22, and the rotated excavating blade 12 is pressed against the diaphysis 22. Thereby, a bone is shaved. Then, the bone drill 1 is further pushed into a predetermined position, and a pilot hole is provided around the guide pin 24.

  Here, the shaved bone becomes a columnar shape and is taken into the cavity 9 while touching the blade inner surface 27 from the opening 10. The captured bone 17 is released from the pressure from the bone body and tries to expand by touching the blood. Therefore, when the bone drilling drill 1 has a simple cylindrical shape, the outer surface 18 of the capture bone 17 exerts pressure radially outward on the blade inner surface 27 and the main body inner surface 26, and the outer surface 18 and the blade portion The inner surface 27 and the main body portion inner surface 26 are closely attached and fixed. In the bone drilling drill 1 in the present embodiment, the inner diameter φ1 is set smaller than the inner diameter φ2, and therefore the outer diameter of the capture bone 17 is smaller than the inner diameter φ2. Therefore, a clearance d is provided between the outer surface 18 and the main body inner surface 26 in the cavity 9. Therefore, even if the capture bone 17 is about to expand, the clearance d allows expansion radially outward.

At this time, the outer surface 18 is in a non-contact state with the main body portion inner surface 26, and friction between the outer surface 18 and the main body portion inner surface 26 does not occur. Therefore, since only the friction between the outer surface 18 and the blade portion inner surface 27 is generated, the overall frictional force is reduced. Therefore, when the bone drilling drill 1 is pulled out from the diaphyseal portion 22 and removed from the drill body after providing the pilot hole, the incorporated bone 17 is easily taken out from the open end on the proximal end side of the bone drilling drill 1.
In addition, the treatment after providing the pilot hole is as described above.

  As described above, according to the bone drilling drill 1 in the present embodiment, the inner diameter φ1 of the blade portion 7 is set to be smaller than the inner diameter φ2 of the main body portion 2, and therefore, the outer surface 18 of the capturing bone 17 and the inner surface 26 of the main body portion. The friction in the length direction between the bone drilling hole 1 and the bone drilling drill 1 can be easily taken out. Therefore, the bone to be cut when the prepared hole is provided can be easily recovered as a bone fragment, and prompt and appropriate treatment can be performed without using an artificial bone or the like.

  In the present embodiment, the blade portion 7 is provided, but the shape and the like can be changed as appropriate. For example, as shown in FIG. 5, a female screw (friction increasing means) 28 may be provided on the blade inner surface 27 over the entire length in the length direction. The female screw 28 is formed so as to go from the front end to the rear end of the blade portion inner surface 27 when the blade portion 7 is rotated for excavation. That is, at the time of excavation, the capture bone 17 is captured into the cavity 9 via the female screw 28. Under such a configuration, when cutting the bone by bringing the blade portion 7 into contact with each other, a screw is cut on the outer surface of the capturing bone 17, and the above-mentioned between the inner surface of the cutting portion 7 and the outer surface of the capturing bone 17 is performed. Longitudinal friction increases. Therefore, when the main body 2 is pulled in a state where the capture bone 17 is captured in the cavity 9, a force in the same direction acts on the capture bone 17 due to friction. Therefore, the extraction bone 17 can be easily separated from the bone body simply by pulling out the main body 2, and the acquisition bone 17 can be quickly recovered.

(Example 2)
FIG. 6 shows a second embodiment of the present invention.
In FIG. 6, the same parts as those shown in FIG.
This embodiment and the first embodiment have the same basic configuration, and are different only in the following points. That is, in this embodiment, the blade portion 7 and the main body portion 2 are set to have substantially the same diameter, and a plurality of long grooves (grooves) 30 are formed on the inner surface 26 of the main body portion at equal intervals along the circumferential direction. ing. These long grooves 30 extend along the length direction of the main body 2.
The long groove 30 constitutes a mechanism that allows the bone to expand in the radial direction, and the mechanism constitutes a friction reducing means.

  Under such a configuration, when the main body drill is driven and the bone is cut in the same manner as described above, the cut bone is taken into the cavity portion 9. At this time, since the capture bone 17 tends to expand, the outer surface 18 applies a pressure radially outward to the inner surface 26 of the main body. In this embodiment, the long groove 30 allows the intake bone 17 to expand. Therefore, the pressure on the inner surface 26 of the main body portion is released by the allowable amount, and the entire pressure on the inner surface 26 of the main body portion is relieved.

Therefore, the friction in the length direction between the outer surface 18 and the main body inner surface 26 is reduced, and the same effect as described above can be obtained.
Further, since the long groove 30 extends along the length direction, the rigidity of the main body 2 can be maintained even if the bone drilling drill 1 is rotated around the axis of the main body 2.

In the first embodiment, the clearance d is set so that the outer surface 18 of the capturing bone 17 and the inner surface 26 of the main body portion do not come into contact with each other. However, the present invention is not limited to this. The outer surface 18 and the main body portion inner surface 26 may be in contact with each other. Even when both are in contact with each other, the pressure in the radial direction is relieved by the expansion, so that the friction in the length direction between the outer surface 18 and the main body portion inner surface 26 is reduced, and It can be easily taken out.
In the first embodiment, an elastic member may be provided on the inner surface 26 of the main body. Thereby, not only expansion | swelling of the capture | acquisition bone 17 is permitted, but the capture | acquisition bone 17 can be guided in the cavity part 9. FIG. At this time, the elastic member is preferably a member having a friction coefficient as small as possible, and a Teflon (registered trademark) layer or the like may be provided on the surface of the elastic member. Thereby, even if blood adheres to the outer surface 18 of the uptake bone 17, the uptake bone 17 can be easily slipped in the cavity portion 9 and can be easily detached from the main body portion 2.
Moreover, although the dimension was described about the full length of the drill 1 for bone drilling, internal diameter (phi) 1, internal diameter (phi) 2, etc., you may change each setting dimension suitably.

Further, in the first and second embodiments, the mechanisms allowing the expansion are described as having different diameters and having the long groove 30, but the present invention is not limited to this, and other configurations are used. There may be.
In addition, although a mechanism that allows expansion is described as the friction reducing means, the present invention is not limited to this, and other friction reducing means are also possible. For example, a Teflon (registered trademark) layer formed by Teflon (registered trademark) processing may be provided on the inner surface 26 of the main body, or lubricating oil or chemicals may be used. Furthermore, you may make it combine these other friction reduction means and the said 1st or 2nd Example.
Further, although the female screw 28 is provided as the friction increasing means, the present invention is not limited to this, and other friction increasing means are possible. For example, the inner surface of the blade portion 7 may be provided with a taper such that the tip diameter is gradually narrowed, a step such that the tip is narrowed, and the like.
Further, the bone drilling drill 1 has been described as a bone drilling instrument, but the present invention is not limited to this, and can be applied to various bone drilling instruments such as a reamer.
Furthermore, although it demonstrated as a treatment of a femoral neck fracture, it is needless to say that it is not limited to this and can be applied to various fracture treatments.
Note that the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 is a perspective view showing a first embodiment of a bone drilling device according to the present invention. It is a longitudinal cross-sectional view of the bone drilling instrument in a present Example. It is an expanded sectional view which shows the principal part of the instrument for bone drilling in a present Example. It is explanatory drawing which shows a mode when it is going to insert the bone drilling instrument in a present Example in a bone. It is sectional drawing which shows a mode that the internal thread was provided in the blade part inner surface of FIG. It is a cross section which shows the principal part of the 2nd Example of the bone drilling instrument which concerns on this invention. It is a figure which shows the procedure of the insertion operation | work of the conventional guide pin and the osteosynthesis implant, Comprising: (a) is explanatory drawing which shows a mode that the guide pin was inserted, (b) is a description which shows a mode that the pilot hole was provided with the drill (C) is explanatory drawing which shows a mode that the lag screw was inserted, (d) is explanatory drawing which shows a mode that the tube plate was installed, (e) is explanatory drawing which shows a mode that a lag screw and a tube plate are fixed. is there.

Explanation of symbols

1 Bone drill (drilling device)
2 Body 6 Tip (tip)
7 Blade part 9 Cavity part 18 Outer surface 26 Main body part inner surface (inner surface)
27 Blade inner surface (inner surface)
28 Female thread (Friction increasing means)
30 Long groove (groove)
φ1 inner diameter (inner diameter of blade)
φ2 inner diameter (inner diameter of main body)

Claims (6)

In order to insert a bone implant in the bone, a bone drilling instrument for preparing a pilot hole in advance,
A cylindrical main body having a cavity inside;
A blade provided at the tip of the main body,
A bone drilling instrument comprising: friction reducing means for reducing friction between an outer surface of a bone cut by the blade portion and taken into the hollow portion, and an inner surface of the main body portion.   2. The bone drilling device according to claim 1, wherein the friction reducing means includes a mechanism that allows a radial expansion of the taken-in bone.   The bone drilling instrument according to claim 2, wherein the mechanism is configured such that an inner diameter of the blade portion is smaller than an inner diameter of the main body portion.   The bone drilling device according to claim 2, wherein the mechanism includes a groove formed on an inner surface of the main body and extending along a length direction of the main body. .   The bone perforation according to any one of claims 1 to 4, wherein friction increasing means for increasing friction between an outer surface of the bone cut by the blade portion and an inner surface of the blade portion is provided. Appliances. The bone drilling instrument according to claim 5, wherein the friction increasing means is a female screw formed on an inner surface of the blade portion.

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