DE8634674U1 - Bone biopsy kit - Google Patents

Description

Bone biopsy kit

The invention relates to a bone biopsy set according to the preamble of claim I.

Bone biopsy involves taking samples from lesions located in bony organs. These can be hard bone-like processes or soft processes that lie under a bony barrier and are therefore not accessible with other puncture aids.

A known biopsy needle (US-PS 4 306 570) suitable for bone biopsy has two coaxially interlocking tubes that can be rotated relative to each other, each of which has a serrated drill bit at its front end. A gear rotates both tubes in opposite directions to each other, so that the ring-shaped, narrow drill bits cut their way into the tissue as they are advanced. A disadvantage of the known double biopsy needle is that there is a risk that the

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Accounts:

. SaI. Oppenheim jr. & Cie.. Cologne (bank code 37O3O2OO) account no. 1O76O I Deutsche Bank AG. Cologne (bank code 37O 7OO6O) account no. 1165O18 " "Pbstgiro Cologne (bank code 37O1O05O) account no. 654-5OO

the outer core bit gets stuck in the bone tissue due to thermal expansion and the inner core bit gets stuck in the outer one. If the biopsy needle gets stuck in the bone, retraction is not only difficult but also dangerous for the patient.

A well-known bone biopsy instrument, of which the upper

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has a tubular part with a drill bit at the end in the form of a toothing that protrudes outwards, the interior of which is designed as a conical bore. The tubular part is coupled to a drive part. After exposing the bone section to be examined, the bone is drilled with the drill bit at low revolutions. In this device, the drill bit is an integral part of the tubular part, which is only relatively short and difficult to manufacture due to the conical bore.

Another known bone biopsy device (US-PS 4 513 754) has a hollow needle with a trocar. The hollow needle and trocar are pushed forward to the bone and then the hollow needle is pushed out over the trocar. The turning and pushing is done manually. To aspirate fluids, another hollow needle extended to the back can be pushed into the hollow needle, which contains a second trocar adapted to it. Once the body fluid to be sucked out has been reached, the trocar is pulled out and the fluid is drawn off through the inner hollow needle. Both hollow needles form a coherent unit in this type of application.

The invention is based on the object of creating a bone biopsy set of the type specified in the preamble of claim 1, which is suitable for percutaneous applications with the greatest possible protection of the soft tissue and can be manufactured simply and at relatively low cost.

This problem is solved according to the invention with

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given characteristics.

According to the invention, the hollow drill needle is inserted into the body through an outer needle. The outer needle is first pushed up to the bone to be examined using an inserted trocar, whereby the soft tissue in front of it is only pressed apart, but no material is removed. The hollow drill needle is only inserted into the outer needle after the tip of the trocar has reached the bone and the trocar has been removed from the outer needle. The rear end of the hollow drill needle is connected to a rotary motor that causes the hollow drill needle to rotate. Since the hollow drill needle is surrounded by the outer needle for most of its length, with only the front end of the hollow drill needle protruding from the outer needle, there is no risk of damaging or winding up body tissue. The only rotating part that comes into contact with the body tissue is the drill bit as soon as it emerges from the outer needle. Since the external diameter of the core bit is largest at the front end, the core bit creates a cylindrical channel in a hard bone lesion, the diameter of which is slightly larger than that of the rear end of the core bit and that of the hollow drilling needle. Even with thermal expansion of the core bit due to friction on the

Bone material can be easily and without

, force pulled out of the bone again

5 will be.

- The bone biopsy kit according to the invention is suitable

j§ also for taking samples from soft processes, which

They are arranged behind a hard bone line.

I lft Here the hollow drilling needle is used to remove the hard

I bone barrier. Then the

f: Hollow needle removed while the outer needle is in

fy body remains. Through the outer needle a

;1 inner needle with trocar inserted, the front end

f 15 passes through the hole in the bone and into the soft

I lesion. A fine needle can then be used to

f Samples from the soft lesion through the inner needle

:| be removed after the trocar has been removed

^: ji was moved out.
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When drilling with the hollow drilling needle, a drill core is created inside the hollow drilling needle, which when pulled back

>$ the hollow needle remains in this and the

fi is a sample that is being sought. To ensure that the core is easily

:; 25 the hollow needle can be pushed out and

not wedged inside the drill bit, expands

: the inner diameter of the core bit differs from the front

? End to the back.

1 30

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In the following, an embodiment of the invention is explained in more detail with reference to the drawings.

Show it:
5

Fig. 1 shows the components of the biopsy set, with the lengths and diameters of the individual components shown to scale,
10

Fig. 2 an enlarged longitudinal section through the front end of the hollow drilling needle,

Fig. 3 a side view of the core bit of the hollow drilling needle, '{

Fig. 4 the insertion of the outer needle with trocar into the body,

Fig. 5 the beginning of drilling the bone with

the hollow drilling needle,

Fig. 6 sampling with the hollow needle,

Fig. 7 retraction of the hollow drilling needle under

Continuation of the rotation,

Fig. 8 the ejection of the sample from the hollow drilling needle using the sample plunger and
30

Fig. 9: Penetration into a soft lesion located behind a hard bone shell using the inner needle and the trocar.

With reference to Fig. 1, the individual components of the bone biopsy set are first explained ^.

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The outer needle 10 consists of a straight metal tube 11, which is firmly connected to a handle 12 at the rear end and is slightly ground at the front end so that it can be fixed to the bone surface. A ball bearing 13 is embedded in the rear end of the handle 12, into which the hollow drilling needle can be inserted. The ball bearing in the outer needle prevents excessive abrasion of the rotating drilling needle and thus prevents breakages.

The trocar 14 can be inserted into the outer needle 10. This consists of a rigid mandrel that has a handle 15 at the rear end. When the handle 15 hits the rear end of the handle 12, the tip 16 at the front end of the trocar protrudes from the front end of the outer needle 10. The front end of the outer needle 10 is then immediately adjacent to the end of the tip 16.

The hollow drilling needle 17 consists of an elongated rigid tube 18 which carries the ring-shaped drill bit 19 at the front end and is provided with a holder 20 at the rear end which can be inserted into the chuck of a drill or other rotary drive. The shape of the drill bit 19 will be explained later. The outer diameter of the tube 18 is approximately equal to that of the trocar 14. The length of the hollow drilling needle 17 is greater than that of the outer needle 10 so that the drill bit 19 can be advanced by approximately 20 to 30 mm over the front end of the outer needle 10.

The inner needle 21 consists of a tube whose outer diameter is equal to that of the hollow needle 17

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and which has a holder 22 at the rear end. The length of the inner needle 21 (without the holder 22) is approximately 10 mm longer than that of the outer needle 10. The wide trocar 23 can be inserted into the inner needle 21, the tip 24 of which protrudes from the front end of the inner needle 21 when fully inserted. The length of this protruding tip is 7 mm. The front end of the inner needle 21 is ground to avoid a step between the trocar 23 and the inner needle 21.

Finally, the sample plunger 25 is provided,

which consists of a straight, elongated rod, the front end of which is blunt and which serves to eject samples from the hollow drilling needle JL 7. The diameter of the cylindrical sample ram 25 is therefore smaller than the smallest inner diameter of the drill bit 19. The length of the sample ram 25 corresponds approximately to that of the hollow drilling needle 17.

2Q The dimensions of the individual components of a bone biopsy set are listed below:

Outside Inside Length diameter diameter (for the parts 14, 17, 21 and

25 without handle)

Outer needle 10 17 3mm 2 ,5 so 120 so Trocar 14 2.5 now - 127 mm Hollow drill needle 2.4 now 1 ,6 mm 150 so Inner needle 21 25 2.4 now 1 mm 130 so Trocar 23 1.6mm - 152 so Sample plunger 1.0 now - 150 so

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The shape of the drill bit, which is attached to the front end of the tube 18 of the hollow drilling needle 17, is shown in Fig. 2 and 3. The drill bit 19 has a rear tubular extension 26, which fits into the front

y 5 end of the tube 18 inserted and firmly connected to this tube

The part 19a of the drill bit 19 protruding from the tube 18 has a groove extending towards the front end

f increasing wall thickness, whereby the outer diameter

% diameter of part 19a is increased towards the front end and

the inner diameter decreases continuously towards the front end. The peripheral surface of the part 19a is flush with the peripheral surface of the tube 18. At the front end of the part 19a, teeth 27 or points are formed which have radial cutting edges 28, from which arcuate flanks 29 extend into the tooth gaps. Each tooth gap is also delimited by a steep flank 30, so that the teeth 27 have a sawtooth-shaped structure. The hollow drilling needle is driven by a motor with a speed of zero to 400 rpm, while the hollow drilling needle is simultaneously advanced axially. The cutting edges 18 mill an annular passage in the bone, while the drill core penetrates into the interior of the drill bit 19 and is finally taken up by the tube 18.

The decreasing outer diameter of the drill bit from the tip to the end allows the milled bone chips to be pushed away and prevents the drill head from seizing in the bone. The increasing inner diameter of the drill needle allows the sample to easily enter the interior of the needle without getting stuck. The combination of hardened steel at the tip and elastic steel in the shaft area keeps the system elastic.

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With reference to Figures 4 to 7, the use of the instrument for taking samples from a hard bone lesion 30 will now be explained.

According to Fig. 4, after local anesthesia, the outer needle 10 with the trocar 14 inserted is advanced through the skin and the soft tissues surrounding the bones to the bone surface, with the tip 16 of the trocar paving the way. The trocar 14 is then removed and

Bone 30 advanced.

According to Fig. 5, the holder 20 is clamped at the rear end of the hollow drilling needle into the chuck 31 of the electric or pneumatic rotary motor 32. The hollow drilling needle 17 is inserted into the outer needle 10, whereby the drill bit 19 is brought forward to the bone surface 30. After contact with the bone has been made, the rotary drive 32 is switched on and pushed forward, where the drill bit 19 penetrates the bone 30 and in this a ring-shaped drilling cut is created.

In the state according to Fig. 6, the hollow drilling needle 17 is advanced under computed tomography or X-ray control until the desired depth is reached or until the holder 20 hits the ball bearing 13.

Each time the desired depth is reached, the hollow drilling needle 17 is withdrawn while maintaining the previous rotation. After the drill bit 19 emerges from the bone 30, the hollow drilling needle 17 is pulled out of the outer needle 10 and removed from the drill chuck 31 (Fig. 7). In Figs. 4 to 9, the skin surface is designated 33.

There is soft tissue between the skin surface 33 and the bone 30.

When the sampling is completed according to the procedure described above, e.g. in the case of bone-like processes, the outer needle 10 can be removed immediately afterwards.

The respective sample is pushed backwards in the core bit 25 according to Fig. 8 from the front end of the hollow drilling needle 17 by inserting the sample plunger 25 into the drill bit 19. The sample is ejected through the rear end of the hollow drilling needle 17.
15

Fig. 9 shows the case where a soft lesion 35 lies behind a bony surface 34, from which samples are to be taken. The procedure is initially carried out as described above in accordance with Figs. 4 and 5. After the hard bone layer 34 has been drilled through by the drill bit 29, the hollow drill needle 17 is withdrawn, while the outer needle 10 is left in its position. The inner needle 21, which is slightly ground at the front end and in which the thin trocar 23 is located, is pushed into the outer needle 10 and the drill channel of the bone until the tip of the trocar reaches the soft lesion.

In this lesion, the inner needle 21 and trocar 23 can be advanced further, with the tip 24 paving the way. After reaching the intended location, the trocar 23 is withdrawn. Now a fine needle (not shown) with an outer diameter of a maximum of 1.6 mm can be advanced through the inner needle 21.

- 10 -

to take samples from the lesion 35.

The bone blotting kit according to the invention enables the acquisition of both bony samples and soft tissue samples that are preceded by bone.

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Claims (4)

- &igr;&igr; - CLAIMS 1. Bone biopsy set with a tubular part which carries a ring-shaped drill bit (19) at the front end and is rotatable by a rotary drive (32) to be attached to the rear end, the outer diameter of the drill bit (19) being largest at the front end and decreasing towards the rear,
characterized, that the tubular part is a hollow drilling needle (17) in which a rear tubular attachment (26) of the drill bit (19) is fastened, and that an outer needle (?0) with a trocar (14) which can be inserted into it is provided, through which the hollow drilling needle (17) can be pushed forward after the trocar (14) has been pulled out until the front end of the hollow drilling needle (17) projects beyond the outer needle (10). 2. Bone biopsy instrument according to claim 1, characterized in that the inner diameter of the drill bit (19) is smallest at the front end and increases towards the rear. • ·· ItIIt It II··· • · Il ■ · · 4··· 111)11 ··· ·· ·· Il »1 11 11 I It · I 1 > % 1111 I» · · · » : &igr; ti ii ·· ··· t ) It 11 1 - 12 - 3. Bone biopsy instrument according to claim 1 or 2, characterized in that an inner needle (21) is provided which contains a second trocar (23) with its tip (24) protruding from it and which can be inserted into the outer needle (10) and, when fully inserted, protrudes at least about 15 mm. & 4. Bone biopsy set according to claim 3, characterized characterized in that a fine needle is provided which can be inserted into the inner needle (21) after the second trocar (23) has been pulled out until its front end projects beyond the inner needle and which is designed to be suitable for taking samples. IfIf