GB2347862A

GB2347862A - Bone marrow biopsy needle assembly

Info

Publication number: GB2347862A
Application number: GB9906257A
Authority: GB
Inventors: Paul Laurence Cervi
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-03-19
Filing date: 1999-03-19
Publication date: 2000-09-20
Also published as: GB9926427D0; GB9906257D0

Abstract

A bone marrow biopsy needle assembly comprises a cannula 3 having at least one recess 11, 12 along its length. The recesses allow the movement of the distal tip 10 of the cannula when fully lodged in the bone (by the use of lateral and rotatory movements by the operator), thus permitting the easy dislodgement of the biopsy specimen. A handle 2 extends along the cannula to a point 9 to provide a region of expanded diameter, thus limiting the depth to which the cannula may be inserted. A stylet (13) and a connector attachment (17) for attaching an electric drill / screwdriver are provided, both of which have a knob (14, 19) at their proximal ends which are sized to fit matingly within an orifice 6 in the handle to prevent relative movement therebetween. Also provided is a pushrod for retrieving the sample and a sterile sheath for enclosing the drill / screwdriver.

Description

AN IMPROVED BONE MARROW BIOPSY NEEDLE FIELD OF THE INVENTION: The invention related generally to a surgical instrument, known variously as a biopsy needle or cannula that is used to gather tissue, such as bone marrow from living persons or animals for pathological study. More specifically, the invention relates to a biopsy needle having an improved structure for dislodging, retaining and withdrawing the biopsy sample, improved safety by having an expanded section along the shaft of the cannula which prevents the insertion into bone beyond a certain depth, and an improved handle which will accept an attachment enabling direct connection to an electric drill/screw driver if required by the operator.

BACKGROUND OF THE INVENTION: Tissue sampling is a common and important investigation in medical practice. Bone marrow is frequently retrieved for subsequent pathological study-usually taken from the pelvic bone at the posterior superior iliac spine or iliac crest.

Such a site is ideally suited to bone marrow sampling, as in adults there is often three to five centimetres of depth of cancellous bone (containing bone marrow) sandwiched between two 0.5 cm thick dense cortical walls of bone on the bone surfaces.

In the standard bone marrow procurement protocol, using current standard instruments, (such as those disclosed in US Pat. No. 4,262,676 to Khosrow Jamshidi), the patient is prepared with a suitable local anaesthetic, at the appropriate marrow retrieval site. Then a bone marrow biopsy needle is inserted, the cannula having a lumen which accommodates a stylet for initial insertion, and which is removed during the procedure to allow the harvesting of the bone marrow biopsy sample. The stylet distal end may be cut at an angle with the leading edge sufficiently sharp to pierce tissue and bone.

With the stylet in place within the outer cannula, the needle is pushed through the outer layers of flesh until the bone is felt at the tip. The needle and stylet are then pushed approximately 4-5 millimetres until the needle appears to be solidly within the outer cortical bone. The stylet is then removed from the proximal end of the needle, which opens up the core of the needle to the now-surrounding marrow tissue.

The outer needle is then usually advanced another one to three centimetres with a slight twisting motion. It is at this point that the needle may be inadvertently inserted through the cortical bone of the deep surface of the bone and may possibly damage internal organ structures. Often the distal end of the outer needle will also be provided with an angled cut and sharpened leading edge to cut and core the tissue easily. By providing a slight twisting motion as the needle is advanced, usually with no more than quarter or half turns, an appropriate sample is cored from the marrow tissue and enters the inner passage of the marrow needle. At this point, the marrow biopsy sample is ready to be removed from the patient, and it is important that the marrow biopsy sample is retained within the cannula and is detached from the bone at it's distal tip. If the biopsy becomes dislodged from the needle, and falls out of the distal end, the sample is irretrievably lost. The procedure is then unsuccessful and must be repeated from the beginning. In order to retain the sample within the needle, the operator will attempt to dislodge the tip of the sample from the main section of the bone by employing a number of possible strategies the commonest of which are as follows: a) The operator may apply suction during the removal of the cannula-but this frequently fails; b) the operator may attempt to withdraw the cannula slightly, then tilt or rotate it and then advance the canula but this commonly fails and frequently causes distress to the patient; c) the operator may choose to use a modified needle which claims to retain the sample within the cannula (US Pat. No. 3,605,721 to Hallac; Islam; US Pat. No.

5,3074,311 to Hasson; US Pat No to Medic; US Patent No.

5,634,473 to Goldenberg) but these methods suffer disadvantages in that the devices are complex and difficult or expensive to maintain and manufacture, there is a high failure rate, and the biopsy sample size is compromised by or the sample is damaged by the necessary incorporation of devices within the cannula lumen to grip the sample at its tip.

Sometimes when the bone marrow is very soft, as in patients with osteoporosis, almost all of these attempts will be futile because the bone structure is so fragile. Conversely sometimes the bone structure is very fibrotic/sclerotic and it is very difficult to insert the cannula and subsequently to remove the core biopsy piece, since the bone marrow itself is reinforced by the surrounding tissue resulting in failure of the procedure.

The current procedures and instruments are flawed in a number of ways resulting in a difficulty in retrieving the sample from the bone, resulting in damage to or reduction in size of the sample, unnecessary distress and pain for the patient and additional time, work and expense for the operator. In addition, there is generally no safeguard to prevent the overinsertion of the cannula into bone and it is frequently known to occur that the cannula penetrates through the cortical surface on the deep surface of the bone possibly damaging the internal structures of the patient. In some instances the operator encounters marked resistance to the insertion of the cannula, usually due to the dense nature of normal bone in healthy young persons, or due to certain diseases where there is excessive density of bone. In these circumstances, the operator may abandon the procedure or seek help from a stronger operator.

SUMMARY OF THE INVENTION: In view of the deficiencies noted in the known devices and the current protocols, it is an object of the present invention to provide an improved biopsy needle that will sever a tissue sample from the surrounding sample without affecting the size or quality of the sample.

It is another object of the invention to provide a biopsy needle that requires minimal manipulation of the needle at the end of the procedure thus decreasing patient pain and anxiety.

It is a further object of the invention to ensure obtaining a biopsy sample at each attempt, thus decreasing the number of biopsy attempts, and the time, effort and money expended in the overall procedure.

It is another object of the invention to provide a biopsy needle that is simple and inexpensive to manufacture, may be reusable and is simple to operate.

It is yet another object of the invention to provide a safety guard in the form of an expansion along the shaft of the cannula and an electric drill attachment shaft of a length to prevent the over-insertion of the cannula into the bone and avoid the risks related to the penetration of the bone and possible damage to internal organs.

It is a further object of the invention to provide a receiving cavity within the handle of the cannula for an attachment which allows the connection of the cannula to an electric drill/screw driver to assist in the penetration of bone in those circumstances where additional strength is necessary or desirable.

It is a further object of the invention to provide a means of using an electric drill/screw driver in an aseptic surgical procedure and this is achieved by providing a sterile surgical sheath which covers the said electric drill/screw driver.

According to the preferred embodiment of the invention, an improved biopsy needle has: an outer cylindrical cannula having an axially extending lumen therethrough and a cannula handle attached to the proximal end of the cannula the said handle having a recess which will seat the knob of the stylet, the knob of the electric drill/screw driver attachment and the pushrod and at the distal end of the cannula there is an expansion to prevent the over insertion of the cannula into bone and a long longitudinal recess to the tip, which may extend the full thickness of the cannula wall with a sharpened edge which when the cannula is tilted and rotated within the bone, the sharpened recess will excoriate the bone allowing lateral movement of the distal tip of the cannula-and a shorter recess with a sharpened edge contralateral to the longer recess at the tip of the cannula which assists in the cutting off of the biopsy sample during the said tilt and rotational movement of the cannula; a cylindrical stylet having a knob affixed to its proximal end which when inserted coaxially into the cannula, is seated within a recess in the cannula handle which prevents relative rotational movement between the stylet and the cannula; a cylindrical pushrod with a knob at its proximal end and a blunt distal tip which is inserted coaxially into the cannula to free the sample from the cannula after successful harvesting of the sample; an attachment for connecting the cannula to an electric drill/screw driver the said attachment consisting of a cylindrical stylet at the distal end and hexagonal knob at the proximal end which when inserted coaxially into the cannula will connect the cannula to an electrical drill/screw driver enabling the cannula to be driven rotationally by the said drill/screw driver; an electric drill/screw driver consisting of a battery powering an electric motor encased in an insulated cover which drives a chuck through a drive pin; the said chuck fitting the electric drill/screw driver attachment; a sterile sheath which is manufactured from a transparent plastic or rubber compound which is sized to fit around the electric drill/screw driver and to therefore permit the use of this assembly in an aseptic surgical procedure.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, advantages and embodiments than those described above will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments in conjunction with a review of the appended drawings, in which: FIG. 1 is composed of four perspective views of the bone marrow biopsy needle of this invention: FIG. la a top view of the cannula; FIG. lb a perspective view of the cannula and partially inserted electric drill/screw driver attachment; FIG lc a perspective view of the cannula and partially inserted stylet; FIG. ld a perspective view of the cannula and fully inserted stylet.

FIG. 2 is composed of a top perspective view of the cannula (FIG. 2a); a front perspective view of the cannula (FIG. ; and a front cross section of the cannula and inserted pushrod (FIG. 2c).

FIG. 3 is composed of a front cross section of the cannula and fully inserted electric drill/screw driver attachment (FIG.

3a) and a front cross section of the cannula and fully inserted stylet (FIG. 3b).

FIG. 4 is a front perspective view of the cannula, electric drill/screw driver attachment and electric drill/screw driver enclosed within the sterile sheath (FIG. 4a) and a front cross-sectional view of same without sheath (FIG. 4b).

FIGS. 5a-5c are detailed perspective and cross-sectional views of the distal tip of the cannula.

FIGS. 6a-6f are detailed perspective views of the stylet FIG.

6a & FIG. 6f; electric drill/screw driver attachment FIG. 6c & FIG. 6d; and pushrod FIG. 6b & FIG. 6e.

FIGS. 7a-7h are a sequential schematic representation of the operation of the invention by a physician.

FIG. 8 is composed of: FIG. 8a a perspective view of the cannula with a cutaway section; FIG 8b a perspective view of the stylet with a cutaway section; FIG 8c A perspective view of the electric drill/screw driver attachment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS 1 to 8, a biopsy needle has a cannula, a stylet, an electric drill/screw driver attachment, pushrod, an electric drill/screw driver and a sterile sheath for same.

The said components are described in their preferred embodiment as follows: The cannula has a hollow cylindrical centre 1 with a handle 2 at its proximal end an open sharpened distal end 3. The handle has a opening 4 in its upper aspect which is continuous with the hollow centre of the cannula. The opening from superficial to deep is at first round 5 (to accommodate the proximal end of the stylet), then hexagonal 6 (to secure the proximal head of the stylet and electric drill/screw driver attachment), then round 1 (to secure a syringe so that suction can be applied if required and to allow the full insertion of the electric drill/screw driver attachment and pushrod by free communication with the hollow central portion of the cannula).

Ends 7 of handle extend laterally and are formed in a configuration so that the operators hand can easily grip the handle. The lower portion of the handle 8 is extended over the surface of the cannula to a distance from the distal tip equal to the desired maximum length of bone marrow sample, to produce an expansion 9 of the diameter of the distal tip 3 of the cannula this point. This expansion 9 will prevent the cannula from being inserted beyond the said distance as it will be obstructed by the periosteum of the bone 30 during it's insertion. The handle can thus be conveniently be formed from two moulded parts. A Hollow tubular cannula hub is moulded to the proximal end of the cannula and serves to secure the cannula to handle by tight frictional engagement of the hub in an aperture though the distal surface of the bottom of the handle. Hub extends upwardly into hollow portion 4.

The hollow interior of cannula hub is connected in fluid flow communication with the hollow interior of cannula.

The distal tip 3 of the cannula, which is shown in detail in FIG a-FIG 5c is a continuation of the central cylindrical hollow cannula hub and with a sharpened end to permit the cutting of the tissue specimen during insertion and rotation of the needle assembly. The cylindrical tip 3 is further modified by the presence of at least one sharpened recess on the outer surface of the cannula hub, extending from the very tip of the cannula, longitudinally towards the proximal end of the cannula for a distance sufficient to allow the purpose of snaring of the sample described fully below. In the preferred embodiment there are two recesses: the first 11 is at the front of the cannula, in depth the full thickness of the cannula hub wall; and in length approximately 1-2 centimetres extending towards the proximal end of the cannula-the purpose of the first recess is to permit the migration of the cannula tip during gentle tilting and rotational movement of the cannula as shown in FIG 7e and 7f when fully inserted into the bone-creating free fluid space around the cannula tip so that the bone sample is loosened from the main body of the bone. In addition, the full thickness recess allows the ingress of marrow fluid into the hollow central portion of the cannula hub increasing the adhesion of the marrow sample now located within the cannula hub to the internal surface of the cannula hub. The second recess 12 lies opposite to the first recess, at rear of the distal tip, is transmural in depth and extend from the very tip for approximately 2 millimetres. The purpose of this sharpened recess 12 is to assist in the cutting and snaring of the deep tip of the biopsy sample. The design of the cannula distal end 3 is relatively simple as there is no narrowing of the distal end and there are no internal features. The distal tip 3 can be conveniently manufactured by modifying a simple cylinder-sharpening its tip and then cutting two simple longitudinal transmural recesses 11,12 using a suitable cutting tool.

As indicated above, the distal end of the cannula is provided with a long linear recess 11 which may extend the full thickness of the wall of the cannula, and a smaller recess 12 on contralateral surface at the distal tip of the cannula.

Following full insertion of the cannula, the biopsy sample is detached from the underlying bone by a gentle tilting and twisting action by the operator which results in the sharpened recesses at the cannula tip to excoriate a space within the marrow cavity and provides a direct cutting action at the tip resulting in the detachment of the sample from the main body of the bone (FIG. 7e and FIG. 7f). In addition, the tilting and twisting motion, results in the migration of fatty tissue from the main marrow cavity to the free space between the biopsy sample and the inner surface of the cannula, resulting in increased adhesion of marrow sample to the cannula and increasing the likelihood of retrieving the sample successfully. In addition, because there is no narrowing at the distal tip 3 of the cannula, an no internal device for grasping the sample, the sample is almost the full dimension of the internal surface of the cannula providing a maximal size of specimen for a given dimension of needle, thus reducing the pain experienced by the patient.

The stylet having a shaft 13 at its distal end and a knob 14 at its proximal end which fits matingly within the handle of the cannula 4 with the distal end of the stylet 15 extending beyond the distal end of the cannula. When inserted fully into the cannula, relative rotational movement between the cannula and the stylet is prevented by the fitting of the proximal ends of both devices. The knob 14 of the stylet is in tight frictional contact with the shaft 13 and is provided with a proximal projection 16 to provide additional compression resistance to the knob.

The Electric drill/screw driver attachment having a cylindrical shaft 17 of slightly smaller diameter than the internal diameter of the cannula hub 5 allowing its insertion into the cannula from the top end. The distal tip 18 of the shaft corresponds to the position of the expansion on the cannula distal tip and therefore acts a further safe guard against excessive penetration into bone when fully inserted into the cannula and in use. The shaft 17 of the electric drill/screw driver attachment meets its proximal knob 19 in a central position as shown in FIG lb, FIG 6c and FIG 6d. This ensures its full coaxial insertion into the cannula hub and ensures coaxial continuation with the drive pin 20 of the electric drill as shown in FIG. 4b thus stabilizing the assembled apparatus. The proximal end of the electric drill/screw driver attachment is connected by tight frictional contact with a knob which in the preferred embodiment, has a hexagonal shape at two levels as shown in FIG lb, FIG 6c and FIG 6d. The purpose of this shape is to engage the matingly shaped 5,6 recesses in the cannula distally, and a suitably fitting electric drill/screw driver proximally 21 such that operation of the drill results in rotation of the electric drill/screw driver attachment and cannula.

The pushrod having a cylindrical shaft 22 of slightly smaller diameter than the internal diameter of the cannula hub 5 allowing its insertion into the cannula at the top end 4. The length of the shaft is greater than the full length of the cannula so that, when fully inserted into the cannula hub 4 will express any solid contents such as a bone biopsy as shown in FIG 7h. The proximal end of the pushrod is connected by tight frictional contact with a knob 23 for ease of handling.

The pushrod can be inserted into the proximal orifice of the cannula in the cannula handle 4 rather than through the sharpened distal end 3. This has the advantage for the operator of reducing the risk of personal injury.

The electric drill/screw driver in the preferred embodiment having a battery power supply 24 connected to an electric motor 25 connected to a drive shaft 26 and chuck 21 encased within an insulated plastic cover 27. Once charged with electricity, this assembly can be freed of any external wiring and can be conveniently moved to the operation site. The use of low voltage battery power has the advantage that there is no risk of clinically significant electrocution for the patient or operator and it is possible to enclose almost fully the device in a sterile sheath 28 as described below permitting its use in a surgical procedure.

The sterile sheath 28 for the electric drill/screw driver having a shape which is complementary to the outer surface of the electric drill/screw driver so that the electric drill/screw driver can be easily placed within it. In the preferred embodiment, the sheath is fitted with a strap or purse string 29 at its opening so that it will temporarily adhere to the electric drill/screw driver during use, and can be discarded after use (FIG. 4b). The sheath is made of such material that it does not interfere with the function of the electric drill/screw driver, is transparent, so that the operator can visualise and operate the electric drill/screw driver controls during use whilst the sheath is in place.

The procedure for the use of the instrument of this invention is shown in FIG 7a-7h. FIG 7a shows the insertion of a suitable knife or lancet 36 through the anaesthetized patient's skin 31 and subcutaneous tissue 32-allowing the subsequent insertion of the distal cannula tip 3 and the expanded section of the cannula tip 8. The operator then inserts the cannula, with the stylet in the fully inserted position, until the outer cortical bone 30 is penetrated (FIG 7b). The stylet is then removed from the centre of the cannula with the cannula retained in position ready to core a cylindrical section of bone marrow. The canula is then advanced manually (FIG 7c) through the cancellous bone 34 toward the deep periosteal surface 35 by applying a gentle inward force together with a constant rotational movement of the hand; or if resistance is encountered, the electric drill/screw driver attachment can be inserted and the electric drill/screw driver connected (FIG 7d) to supply the necessary rotational movement. The cannula will core a bone marrow specimen 33 to a depth no greater than the length corresponding to the distance of the distal tip 3 of the cannula to the expansion 9 on the cannula shaft. Once the desired depth has been attained, no further inward force need be applied, the operator then tilts the cannula so that pressure is applied to the first, longer recess by the surrounding bone, and a gentle partial rotational motion, twisting back and forward about 45 degrees in each direction, results in the dislodgment of the biopsy 33 tip from the main body of the bone (FIG 7e). If desired, the whole cannula can be rotated 180 degrees and the same procedure carried out tilting now in the opposite direction as shown in FIG 7f. The cannula and biopsy 33 are then withdrawn (FIG 7g) and the pushrod is used to express the biopsy 33 sample from the inside of the cannula tip as shown in FIG 7h.

The present invention provides many improvements on the existing bone marrow biopsy apparatus: The cannula tip 3 design is simple and cheap to manufacture; it results in high quality specimens with no waste as there is no narrowing in the tip 3; it effectively snares the biopsy specimen because of its unique longitudinal ridges 11,12 on the outer surface; it is safer for the patient because the cannula and electric drill/screw-driver adaptor are designed to prevent over insertion of the cannula; it is safer for the operator because the pushrod can be inserted into orifice in the cannula handle 5 rather than the sharpened distal tip 10; The procedure using this invention is less painful for the patient because there is less likelihood of failure and the more efficient tip design allows for the procurement of shorter but still adequate samples; The procedure is less arduous for the operator because of the increased likelihood of retrieving the sample on the first attempt, less effort is needed to free the sample from the main body of the bone as the cutting action of the recesses 11,12 on the cannula tip are placed in direct opposition to the surrounding bone and the operator can invoke if required the electric drill assembly in cases of difficulty.

Although the present invention makes mention of an electric drill/screw driver, we do not claim to be the original inventors of such a device as there are many existing suitable devices commonly available, we claim to have found a new use for these devices by the provision of a suitable means of handling them in an aseptic manner by enclosing them in a sterile sheath during a surgical procedure and by providing them with an adaptor to fit the bone marrow biopsy assembly.

The details of the embodiments of the invention, particularly with regard to the shapes of the recesses at the cannula tip, and the cannula handle may be varied within the scope of the invention.

Apart from bone marrow biopsy, in which the intention is to retrieve a solid sample of bone tissue, the present invention or aspects thereof can equally be applied to the aspiration of fluid from the bone marrow cavity which may be undertaken for diagnostic purposes, or for the retrieval of large volumes of fluid for the purpose of bone marrow transplant from one person to another. The means of covering the electric drill with a sterile sheath, rendering it suitable for use in a surgical procedure could equally be applied to a wide variety of orthopaedic surgical procedures for the creation of bore holes within bones, or for the insertion of screws into bones.

Claims

CLAIMS While the embodiments shown and described above are fully capable Of achieving the objects and advantages of the present invention, it is to be understood that these embodiments are shown and described solely for the purposes of illustration and not for limitation. Accordingly, many additions, modifications and substitutions are possible without departing from the scope and spirit of the invention as defined in the accompanying claims.

What is claimed is:

1. A biopsy needle assembly comprising: an elongated tubular cannula, having an axially extending lumen therethrough and having distal and proximal ends, a cannula handle attached to the proximal end of said cannula, said cannula handle extending transversely to the axis of said cannula and having a cavity aligned with and open to the proximal end of said cannula, a distal end of said cannula which is bevelled and sharpened and in free fluid communication with the proximal end, a recess or recesses on the outer surface of the said cannula distal end, an expansion on the outer surface of the said cannula distal end, an orifice in said cannula handle in fluid flow communication with said cannula lumen, said orifice being coaxial with said cannula lumen, a stylet having a knob affixed to its proximal end, said knob being sized to fit matingly within said orifice, an elongated stylet shaft extending from said knob, slidably received within said cannula lumen, said stylet having a sharpened distal tip which extends distally from the distal end of said cannula, said orifice retaining said knob so that force may be rotatably applied around either axis direction of said elongated stylet positioned in said orifice without relative rotation between elongated stylet and said elongated cannula, a connector attachment having a knob affixed to its proximal end, said knob being sized to fit matingly within said orifice, said connector attachment having a shaft affixed to its proximal end, said knob and shaft being sized to fit within said orifice of cannula handle distally and said knob sized to fit an electric drill or electric screw driver proximally, said orifice retaining said knob of said connector attachment so that force may be rotatably applied around either axis direction of said elongated connector attachment positioned in said orifice without relative rotation between elongated connector attachment and said elongated cannula, an electric drill or electric screw driver, a sheath which is sized to fit around said electric drill or electric screw driver, said sheath having an opening to receive said electric drill or said electric screw driver, said opening having a strap or string to enclose said electric drill or said electric screw driver, a pushrod having a knob affixed to its proximal end, said knob being sized to fit slibably within said orifice, an elongated shaft extending from said pushrod knob, slidably received within said cannula lumen, said pushrod having a blunt distal tip which extends distally from the distal end of said cannula, 2) An assembly according to claim 1 wherein said orifice is contained in a cannula hub moulded to the proximal end of said cannula.

3) As assembly according to claim 2 wherein said cannula is secured to said handle by tight frictional engagement of said cannula hub in an aperture through the distal surface of said cannula handle.

4) An assembly according to claim 3 wherein said handle comprise a distal component and a proximal component separate from but connected to each other and are formed integrally.

5) An assembly according to claim 4 wherein said proximal portion is formed all of one piece comprising two opposed lateral ends forming the proximal part of said handle connected by a central portion fitting within said cavity that interconnects said lateral ends.

6) An assembly according to claim 5 wherein said central portion has an aperture to receive the cannula hub and proximally extending cavity that are adapted to engage the knob of said stylet and knob of said connector attachment.

7) An assembly according to claim 6 wherein said cannula sharpened distal end is modified to have the means to retain the biopsy sample, without compromising biopsy sample size, by having a recess or recesses formed on its outer surface which may extend through the cannula wall.

8) An assembly according to claim 7 wherein said recess or recesses have sharpened edges to cut away surrounding bone and detach and snare the biopsy sample.

9) An assembly according to claim 8 wherein said recess or recesses are formed by cutting through the cannula distal tip in a linear fashion from the distal end towards the proximal end of the cannula.

10) An assembly according to claim 9 wherein said cannula distal end having an expansion on the outer surface along the cannula shaft.

11) An assembly according to claim 10 wherein said expansion is positioned along the shaft to limit the size of the biopsy sample.

12) An assembly according to claim 11 wherein said expansion is formed by the distal extension of the said cannula handle.

13) An biopsy needle as in claim 1, further comprising means for selectively attaching and detaching said connector attachment and said electric drill and electric screw driver.

14) An assembly according to claim 13 such that said connector attachment and cannula and electric drill are in coaxial alignment when engaged.

15) An assembly according to claim 14 such that the said connector attachment and cannula are irrotatably engaged such that operation of the electric drill or screw driver results in uniform coaxial rotation of the connector attachment and cannula.

16) An assembly according to claim 15 such that said connector attachment can be easily disassembled from said cannula.