WO2010066221A1

WO2010066221A1 - Drilling method, drilling machine intended for surgical purposes having an attachment, and attachment for a drilling machine intended for surgical purposes

Info

Publication number: WO2010066221A1
Application number: PCT/DE2009/001518
Authority: WO
Inventors: Johannes Klotz; Friedrich-Wilhelm Bach
Original assignee: Gottfried Wilhelm Leibniz Universität Hannover
Priority date: 2008-12-10
Filing date: 2009-10-30
Publication date: 2010-06-17
Also published as: DE102008061249A1

Abstract

The invention relates to a drilling method, to a drilling machine (1) intended for surgical purposes having an attachment (2) and a drill (4), and an attachment (2) for a drilling machine (1). In order to significantly reduce undesirable heat input into the tissue due to drillings in an implant material, a coolant can flow through the drill (4). After exiting through an outlet opening (7) in the region of the drill bit of the drilling site, the coolant is fed together with the chips present therein along the flute of the drill (4) to a cylindrical chip receptacle (8), which radially encloses the drill (4).

Description

A drilling procedure, a surgical drill with an attachment, and an attachment for a surgical drill

The invention relates to a drilling method, a drill intended for surgical purposes with an attachment and a fixable to the attachment by means of a coupling element drill and an attachment for a certain purpose surgical drill.

Such a drilling machine and such a drilling method are used in practice, for example, to allow a screw connection of fracture surfaces by means of an osteosynthesis plate and thereby promote the convergence of the affected bones. For this purpose, the osteosynthesis plate is screwed with several screws in each half of the broken bone, in order to connect them.

With increasing age, signs of wear and tear increasingly appear today, which affect the joint apparatus in particular and thus require a partial or complete joint replacement. Currently, in Germany alone, around 300,000 artificial knee and hip joints are implanted each year. Since these patients are now very mobile again after a successful therapy and actively participate in the social life, fractures of bones in which artificial joints are anchored are increasing in recent years.

The unnatural force distribution in the bone caused by the implant has a significant influence on the fractures that occur due to the significantly increased elastic modulus of the implant material compared to the bone. This load shielding in the bone leads to a decay of the bone substance and correspondingly reduced stability. In addition, under stress at the lower end of the implant shaft stress peaks are formed, which consequently lead here to a fracture of the bone. To fix the fracture surfaces by means of an osteosynthesis plate, it is necessary in these cases to fasten the screws on both sides of the prosthesis shaft in the bone.

However, it proves disadvantageous in practice that a fixation of the fracture is greatly impeded due to the weakened by the internal prosthesis stem bone substance.

DE 10 2006 058 937 A1 relates to a drilling machine with a receptacle, which has a contact surface for a region facing away from the drill of a prosthesis shaft of a prosthesis, in particular a joint prosthesis, receiving bone. The drill serves to introduce a hole in the bone and in the prosthesis shaft, so that the screw can be made not only in the bone structure, but also in the prosthesis stem.

DE 199 55 026 B4 has already described a hand drill which is intended for introducing an elongate fixing aid into a bone under sterile conditions. The hand drill is equipped with a motor-driven rotatable drive shaft, which is kinematically connected to a drill wire chuck. The drill wire chuck is designed to be open in such a way that the fixing aid can be guided through the drill wire chuck in an open position and is non-rotatably connected to the drill wire chuck in a closed position.

DE 103 02 873 B3 relates to a drill system which can be used in surgery, comprising a drive part and a functional part, wherein the drive part consists of a non-magnetic metal.

Furthermore, DE 295 04 857 U1 describes a drilling jig as a guide for a drill for surgical drills with a sleeve which can be attached with its front end to a bone, through the interior of which the drill can be screwed into the bone, and with a stop face at the rear end, at a stop the depth of the drill into the sleeve limiting stop of the drill can rest. The drill guide is provided with means for varying the distance between the stop surface and the front end of the sleeve so as to allow the surgeon to safely insert bores into the bone. DE 693 26 397 T2 already discloses a device for machining a workpiece with a tool holder and a rotating cutting tool, which has a coolant channel on an outer surface. This extends from the rear end of the cutting tool to a region near the free end, so that the coolant is applied directly to the rake surfaces of the cutting edges of the cutting tool.

By DE 23 31 023 C3 a drill for dentistry is known. The drill has a longitudinal channel for the supply of coolant to the tool, which opens at the working end of the tool to the outside. The cooling liquid also enters the milling head cavity through the openings, wherein drilling dust is also swept into the milling head cavity. In this way, the heat is to be reduced at the place of its formation, ie at the point where the cutting surfaces rub against the substance to be removed.

Also known from DE 10 2006 016 290 A1 a drill for machining, which has an internal coolant supply.

Further, DE 27 30 227 A1 relates to an apparatus for drilling bone, in which the drill is driven with a reciprocating rotary motion whose amplitude is smaller than a full revolution. According to a variant, a sleeve surrounds the drill, which is pressed forward against the bone to form a channel for receiving the waste. Although the chips are thereby collected in the sleeve, but not led away from the drilling site.

A disadvantage found in the known from the prior art drilling machines for surgical purposes associated with drilling in implants high heat, so that the released metal chips that store the heat energy can lead to damage to the tissue, since any increase in temperature above 42 ⁰ C is to be avoided within the human body. In addition, drilling machines for machining high-strength materials are necessarily designed as drill presses, since an axial coolant supply due to the sealing side of the processing zone side facing previously could only be realized by a frictional connection of the drill with a chuck, which has the consequence that a manual drilling and a manual drilling device could not be realized. Against this background, the object of the invention is to provide a substantially improved drilling method and an attachment intended for carrying out the method for a manual drill used in surgery, as well as a manual drill provided with such an attachment, whereby an undesirable heat input, in particular due to drilling in implant materials, is significantly reduced.

This object is achieved by a drilling method according to the features of claim 1. The further embodiment of the drilling method can be found in the dependent claims 2 to 6.

According to the invention, therefore, a drilling method of a drill intended for surgical purposes for introducing bores into bone and fixed therein implants is created by following a coolant through a drill of a secondary cutting edge in the implementation of the drilling process and following the twist angle of the drill behind at least one main cutting edge of the drill emerges. The coolant is deflected into an area behind a chip to be generated and thereby flows around the chip and the drill. In this way, the separated chip is transported according to the direction of rotation of the drill from the coolant through a flute of the drill to a drill bit facing away from the chip receiving and collected by a chip receiving. The chip holder includes the drill and adapts to the drill penetration depth accordingly. An undesirable heat development is thereby avoided in a simple manner by the resulting chips are transported together with the exiting through the outlet opening in the processing zone coolant along a flute of the drill through the opening into the interior of the chip receiving. The particles heated to an undesired temperature, in particular metallic chips of the implant material, thus do not pass uncontrollably into the surrounding tissue. Rather, the chips are conveyed on the outside of the drill in the chip holder. This ensures not only a reliable removal of the chips, but also an uninterrupted cold chain of the chips.

The object is further achieved with a drill intended for surgical purposes with an attachment by the drill is designed as a permeable by a coolant hollow body with an outlet for the coolant in the region of a drill bit and with a drill radially enclosing chip receiving, which an opening for the drill, wherein the chip receiving and the drill are movable relative to each other in the direction of an axis of rotation of the drill. The invention is based on the recognition that a damaging influence due to a possible heat input into the tissue can be avoided in a simple manner that resulting chips are transported together with the emerging through the outlet opening in the processing zone coolant along a flute of the drill through the opening into the interior of the chip holder. The hot metallic chips of the implant material thus do not pass uncontrollably into the surrounding tissue. Rather, the chips are conveyed on the outside of the drill in the chip holder. This ensures not only a reliable removal of the chips, but also an uninterrupted cold chain of the chips.

A particularly advantageous embodiment of the present invention is achieved in that the drill has a plurality of outlet openings, in particular inclined with respect to the rotational axis of the drill, for the coolant. In this way, a particularly efficient cooling of the resulting chips is ensured, in particular by each main cutting edge is associated with a separate outlet opening. Thus, therefore, a sufficient flow through each flute is achieved, with an inclined arrangement of the outlet opening significantly improves the conveying effect. An undesirable, in particular uncontrolled distribution into the surrounding tissue is excluded. In addition, no feed movement is produced by the exiting coolant jet in the opposite direction.

In a further, likewise particularly practical modification, at least one outlet opening for deflecting the coolant into an area directly behind a main cutting edge of the drill is executed. With this arrangement, the coolant jet enters the gap between the chip and the main cutting edge, so as to achieve the greatest possible cooling effect directly in the area of chip formation. Possible chip residues are lifted by the blasting action of the coolant and thus arrive reliably in the flow of coolant return into the chip receptacle.

In this case, the chip removal is further improved by biasing the chip receptacle by means of the biasing force of a particular spring element against a processing zone. As a result, due to the prestressing force, the chip receiving device reliably automatically lays against the edge region enclosing the borehole. As a result, the respective minimum distance of the chip receiving is ensured with respect to the drill bit, so as to keep the residence time of the chips in the tissue as short as possible. The chip holder can in turn have a thermal insulation so as to minimize heating of its outer wall surface to a minimum. The biasing force can also be made adjustable. Furthermore, it is advantageous if the chip receiving rotatably connected to the housing of the drill and thus has a high stability.

In addition, it proves to be particularly practical if the chip receiving an elastic or deformable contact surface for abutment against a processing zone enclosing the edge region of the bone to avoid unwanted escape of chips through a gap between the chip receiving and the edge region of the borehole. For this purpose, the abutment surface may, for example, have a recess corresponding to the inner diameter of the chip receptacle, for example, be annular. The contact surface can also be connected for single or multiple use releasably connected to the chip receiving.

Furthermore, it is according to a development advantageous if the chip receiving is connected to a suction. This allows a simple removal of the entering into the chip receiving coolant, so that the volume of the chip receiving only needs to be dimensioned according to the chip volume and thus relatively small. Furthermore, a negative pressure can be generated in the interior of the chip receptacle so as to favor the return flow of the coolant exiting at the drill bit, including the chips.

The proportion of traceable coolant in this way is comparatively high. In addition, however, it is particularly expedient if the coolant is a biocompatible liquid, in particular a saline solution, and thus no adverse effects on the tissue or the bone substance is to be feared.

Particularly useful, however, is a modification in which the coupling element frictionally receives the drill on the side facing the processing area, then on the other side is positively connected to the primary drill chuck, which in turn radially supplied with coolant and form-fitting with the actual chuck, here secondary chuck , a drill intended for surgical purposes can be connected. This results in a non-axial coolant supply with at least one cooling channel, which is necessary for the manual use of a corresponding device, since a replacement of the tool can be realized by a positive connection, since a coolant seal by screwing a seal screw on the primary drill chuck realized the sealing of the system , Of course, the various components of the drill can form a permanently connected unit. On the other hand, a variant in which the attachment receives the drill chuck in a releasably releasable manner in order to be able to ensure a simple change of the drill when the functionality is otherwise the same is particularly useful.

It is in principle conceivable that only the drill per se can be flowed through by the coolant by a corresponding coolant supply is directly associated with the drill.

Furthermore, it proves to be particularly helpful if the drill has a plurality of coolant channels, which have a spiral course according to the course of the respective main cutting edge. The cooling effect can be improved due to the reduced distance from the cutting edge.

In addition, it is particularly promising if the drill is designed as a carbide drill and thus allows the introduction of holes not only in the bone tissue, but also with little effort in the implant easily.

The further object of providing a surgical attachment with a coupling element for a drill, is achieved in that on the essay a drill is fixed, which can be flowed through by a coolant hollow body with an outlet for the coolant in the region of a drill bit is executed, with a drill radially enclosing chip receiving, which has an opening for the drill, wherein the chip receiving and the drill are movable relative to each other in the direction of an axis of rotation of the drill. In this way, according to the invention, the drilling of implants anchored in the bone is made possible with all drills known in surgery, by the coolant supply in conjunction with the return of the chips along the outside of the drill, in particular along the flute, in the chip receiving an undesirable heat input into the body is reduced to a harmless level. The decisive factor is not only the supply of the coolant to the drilling site, but rather the return of at least a large part of the coolant together with all released chips whose heat otherwise leads to a possible tissue damage when the coolant flow is increased. It is particularly useful if the article is detachably fixable to the drill, so as to enable a universal, so in particular as needed use of the thus designed essay in various drills. Of course, the essay can be equipped for this purpose with adapters or different fixatives for several commercial drills.

In this case, the article has a relative to the drill stationary coolant supply, which can be connected in such a simple manner with a supply line. The handling of the drill is thereby made difficult in any way, the coolant supply can be controlled or regulated according to the rotation of the drill.

Another, likewise particularly expedient embodiment is achieved in that the coolant supply is connected to a cylindrical, the drill concentrically enclosing chip receiving. The chip holder consists of two telescopically displaceable cylindrical hollow bodies, which are connected to the housing of the drill. A compression spring is used to apply a biasing force against the edge region of the bone and thus a reliable investment. After completion of the front part can be removed and the collected chips inside can be disposed of.

The invention allows for various embodiments. To further clarify its basic principle, one of them is shown in the drawing and will be described below. This shows in

Figure 1 is a sectional side view of a drill with an essay.

FIG. 2 is an enlarged view of the attachment shown in FIG. 1 with a coupling element; FIG.

FIG. 3 is an enlarged view of the coupling element shown in FIG. 2; FIG.

Fig. 4 is a further enlarged view of a drill.

A drilling machine 1 intended for surgical purposes will be described in more detail below with reference to FIGS. 1 to 3. The per se commercial drill 1 is equipped with an attachment 2, which receives a drill 4 by means of a coupling element 3. In order to realize the introduction of a bore in a titanium implant designed as a prosthesis in a comparatively short time with simultaneous reduced heat input of the resulting frictional heat into the tissue and simultaneous removal of the chips, the drill 4 has a through-flow of a coolant drill 4, in particular a carbide drill , on. The drill 4 is this fixed to a primary chuck 5 by shrinking positive and positive. The coupling element 3 is then in turn positively connected to a primary chuck 5, which in turn is positively connected to the secondary chuck of the drill 1, so as to transmit the required torque reliably. The chuck 5 and the attachment 2 are equipped with an internal, continuous coolant supply 6, so that a continuous coolant supply of the drill 4 - and after the exit through an outlet opening 7 in the region of the drill tip and the drilling - is guaranteed. The isotonic coolant is then fed together with the chips contained therein along the flute, not shown, of the drill 4 to a cylindrical chip receiving 8, which radially encloses the drill 4 and has an opening 9 for the drill 4. The chip holder 8 and the drill 4 are relative to each other in the direction of a rotation axis 10 of the drill 4 slidably, so that the chip holder 8 by means of the biasing force F of a spring element 11 is biased against a processing zone, so as to ensure a reliable abutment against the bone. The chip holder 8 is connected to an exhaust 12, so that only the chips remain in the interior of the chip holder 8 and can be easily removed from the chip holder 8 after completion of the hole.

In FIG. 4, the drill 4 is shown in a greatly enlarged detailed representation during the execution of the drilling procedure when the bores 20 are introduced into a bone 13 and an implant 14 fixed therein. Evident is the arranged in the region of a drill tip outlet opening 7 for the coolant, which emerges following a direction of rotation 15 of the drill 4 behind a main cutting edge 16. The coolant is deflected into a region behind a chip 17 to be generated and thereby flows around the chip 17. In this way, the separated chip 17 is turned away from the coolant through a flute 18 of the drill 4 to that of the bore in accordance with the direction of rotation 15 of the drill 4 Chip 8 transported and collected by this. The chip holder 8 includes the drill 4 by means of a seal 19 and is axially movable according to the Bohrereindringtiefe.

Claims

1. Drilling method of a drill intended for surgical purposes (1), in particular for introducing bores (20) into bone (13) and fixed therein implants (14), characterized in that in carrying out the drilling process, a coolant through a drill (4 ) is guided following a secondary cutting edge, following the helix angle of the drill (4) behind at least one main cutting edge (16) of the drill (4) is deflected behind at least one chip to be generated (17), which thereby the chip (17) and the Drill (4) lapped, the direction of rotation (15) of the drill (4) corresponding to the separated, surrounded by the coolant chip (17) by a flute (18) of the drill (4) to a drill (4) facing away from the chip receiving (8 ) and caught by an adapted by the drill (4), the Bohringeindringtiefe corresponding, adaptive chip receiving (8) is collected.

2. Drilling method according to claim 1, characterized in that initially organic tissue and then within the same drilling process, an implant material is machined boring.

3. Drilling method according to claim 1 or 2, characterized in that an isotonic liquid is used as the coolant.

4. Drilling method according to at least one of the preceding claims, characterized in that the coolant is led out of at least one main free surface.

5. Drilling method according to at least one of the preceding claims, characterized in that the coolant is led out of at least one rake face.

6. Drilling method according to at least one of the preceding claims, characterized in that the chip holder (8) is held at a constant distance from an edge region of a bore (20).

7. A drill intended for surgical purposes (1) with an attachment (2) and a on the attachment (2) by means of a coupling element (3) fixable drill (4), in particular for introducing bores (20) in bone (13) and implants (14) fixed therein, wherein the drill (4) is designed as a hollow body through which a coolant can flow in the region of a drill tip, characterized by a chip receptacle (8) radially enclosing the drill (4) ), which has an opening (9) for the drill (4), wherein the chip receiver (8) and the drill (4) relative to each other in the direction of a rotation axis (10) of the drill (4) are movable.

8. Drilling machine (1) according to claim 7, characterized in that the drill (4) has a plurality, in particular with respect to the rotational axis (10) of the drill (4) inclined arranged outlet openings (7) for the coolant.

9. Drilling machine (1) according to claims 7 or 8, characterized in that at least one outlet opening (7) for deflecting the coolant in an area immediately behind a main cutting edge (16) of the drill (4) is executed.

10. Drilling machine (1) according to at least one of claims 7 to 9, characterized in that the chip holder (8) by means of the biasing force (F) in particular a spring element (11) against a processing zone (bore 20) is prestressed.

11. Drilling machine (1) according to at least one of claims 7 to 10, characterized in that the chip holder (8) has an elastic and / or deformable contact surface for abutment against a bone (13).

12. Drilling machine (1) according to at least one of claims 7 to 11, characterized in that the chip receiving means (8) is connected to a suction device (12).

13. Drilling machine (1) according to at least one of claims 7 to 12, characterized in that the coupling element (3) the drill (4) and a drill (4) by means of a shrink fit frictionally and / or positively fixing drill chuck (5) ,

14. drilling machine (1) according to claim 13, characterized in that the coupling element (3) receives the drill chuck (5) releasably releasably.

15. drilling machine (1) according to at least one of claims 7 to 14, characterized in that the attachment (2), the coupling element (3) and the drill (4) can be flowed through by the coolant.

16. Drilling machine (1) according to at least one of claims 7 to 15, characterized in that the drill (4) has a plurality of coolant channels.

17. Drilling machine (1) according to at least one of claims 7 to 16, characterized in that the drill (4) is designed as a carbide drill.

18. An attachment (2) intended for surgical purposes with a coupling element (3) for a drilling machine (1), characterized in that on the attachment (2) a drill (4) can be fixed, which as a through-flow of a coolant hollow body with an outlet opening (7) for the coolant in the region of a drill tip, with a drill (4) radially enclosing chip receiving (8) having an opening (9) for the drill (4), wherein the chip receiving (8) and the drill (4) are movable relative to each other in the direction of a rotation axis (10) of the drill (4).

19. attachment (2) according to claim 18, characterized in that the attachment (2) releasably on the drill (1) can be fixed.

20. attachment (2) according to claim 18 or 19, characterized in that the attachment (2) has a relative to the drill (4) stationary coolant supply (6).

21. attachment (2) according to claim 20, characterized in that the coolant supply (6) with a cylindrical, the drill (4) concentrically enclosing chip receiving (8) is connected.