(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`(19) World Intellectual Property
`=
`Organization
`International Bureau
`
`(43) International Publication Date
`30 October 2014 (30.10.2014)
`
`WIPO! PCT
`
`(31)
`
`International Patent Classification:
`A6IB 17/16 (2006.01)
`A6IB 17/32 (2006.01)
`
`(81)
`
`(21)
`
`International Application Number:
`
`PCT/IL2014/050381
`
`(22)
`
`International Filing Date:
`
`Filing Language:
`
`Publication Language:
`
`24 April 2014 (24.04.2014)
`
`English
`
`English
`
`Priority Data:
`61/815,714
`61/859,214
`61/903,082
`
`24 April 2013 (24.04.2013)
`27 July 2013 (27.07.2013)
`12 November 2013 (12.11.2013)
`
`US
`US
`US
`
`(84)
`
`(25)
`
`(26)
`
`(30)
`
`(71)
`
`(72)
`
`(10) International Publication Number
`WO 2014/174521 Al
`
`Designated States (unless otherwise indicated, for every
`kind G national protection available): AE, AG, AL, AM,
`AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY,
`BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM,
`DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT,
`HN, HR, HU, ID, IL, IN, IR, IS, JP, KE, KG, KN, KP, KR,
`KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, ME,
`MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ,
`OM,PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA,
`SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM,
`TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM,
`ZW.
`
`Designated States (unless otherwise indicated, for every
`kind ¢ regional protection available): ARIPO (BW, GH,
`GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, SZ, TZ,
`UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ,
`TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK,
`EE, ES, FI, FR, GB, GR, HR, HU,IE,IS, IT, LT, LU, LV,
`MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM,
`TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW,
`KM, ML, MR, NE, SN, TD, TG).
`
`Applicant: T.A.G. MEDICAL DEVICES - AGRICUL-=
`TURE COOPERATIVE LTD.[IL/IL]; Kibbutz Gaaton,
`2513000 Doar-Na Oshrat (IL).
`
`Inventors: MIROCHINIK, Aryeh; 11/9 Moshe Shapiro
`Street, 2440912 Akko (IL). SITRY, Hagay; Kibbutz
`Gesher HaZiv, 2281500 Doar-Na Galil MaAravi
`(IL).
`HAZIZA, Rafl; 2 Lehi Street, 27235 16 Kiryat-Bialik (IL).
`
`Declarations under Rule 4.17:
`
`(74)
`
`Agents: G.E. EHRLICH (1995) LTD. et al;, 11 Mena-
`chem Begin Road, 5268 104 Ramat Gan (IL).
`
`gd inventorship (Rule 4.17(iv))
`Published:
`
`with international search report (Art. 21(3))
`
`[Continued on nextpage]
`
`(54) Title: BONE MATERIAL REMOVAL DEVICES
`
`\
`
`(57) Abstract: The present invention in some embodiments thereof, relates
`
` to bone material removal devices (2100), for example, devices which change
`
`In some embodiments, a bone removal device comprises
`effective diameter.
`an expandable portion.
`In some embodiments,
`the expandable portion com-
`prises one or more bone removing elements such as cutting teeth (2106). In
`some embodiments, a cutting tooth is movable between an openposition,
`in
`which it is configured to widen a bore in a bone, and a closed position.
`In
`some embodiments, a cutting tooth of the bone removal device is formed
`with a curved, such as convex, cutting face (21 14).
`
`
`
`
`
`wo2014/174521AA.IMMTIAIDAIUINNTTTNTATTAA
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`

`

`wo 2014/174521 AY Wt alllMf 0 QhDoh, MME eval
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`—__before the expiration d the time limitfor amending the
`claims and to be republished in the event of receipt of
`amendments (Rule 48.2(h))
`
`

`

`WO 2014/174521
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`PCT/IL2014/050381
`
`BONE MATERIAL REMOVAL DEVICES
`
`FIELD OF THE INVENTION
`
`The present invention in some embodiments thereof, relates to bone removal
`
`tools, for example, tools which change effective diameter.
`
`SUMMARY OF THE INVENTION
`
`According to an aspect of some embodiments there is provided a bone material
`
`removal devicc comprising an clongatcd shaft, at
`
`least onc bone matcrial removal
`
`10
`
`element for widening a bore in a bone, the element coupled to the shaft,
`
`the element
`
`movable from a closed position, in which the element is only partially received within
`
`the shaft, to an open position in which the element extends radially away from the shaft,
`
`wherein the shaft comprises a section defining a generally cylindrical volume of
`
`rotation, and at least a portion of the bone removal element extends beyond the volume
`
`15
`
`of rotation when the elementis in the closed position.
`
`In some embodiments, the bone material removal element is a pivotable cutting
`
`tooth coupled to the shaft by a hinge.
`
`In some cmbodiments,
`
`the portion of the bone removal clement protrudes to a
`
`distance ranging between 0.05 mm to 0.5 mm from the volumeofrotation of the shaft
`
`20
`
`when in the closed position.
`
`In some embodiments, the cutting tooth comprises a cutting face formed with a
`
`concavity. Optionally, a radius of curvature of the concavity ranges between 1.5 mm- 4
`mim.
`
`In some embodiments, the cutting tooth comprises a cutting face formed with a
`
`25
`
`flat portion.
`
`In some embodiments, the tooth freely pivots on the hinge to open as a result of
`
`reversal of rotation direction of the device.
`
`In some embodiments,
`
`the hinge comprises proximal and distal elongated
`
`extensions received within the shaft to firmly attach the hingeto the shaft.
`
`30
`
`In some embodiments,
`
`the shaft comprises a recess
`
`shaped and sized for
`
`receiving at least a portion of the tooth, the recess shaped to limit rotational movement
`
`of the tooth.
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`WO 2014/174521
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`In some embodiments,
`
`2
`the device is a drill bit, and the shaft comprises one or
`
`more flutes.
`
`In some embodiments, a concavity at
`
`the cutting face of the tooth faces a
`
`diametrically opposing direction from the flute of the shaft when the tooth is open, to
`
`provide an additional path for removal of extracted bone material.
`
`In some embodiments, a bottom surface of the cutting tooth is non-planar to
`
`engage an irregular geometry of the bone surface.
`
`In some embodiments,
`
`the shaft comprises a tapering head having a pointed
`
`distal tip.
`
`10
`
`15
`
`In some embodiments, the bone removal element includes at least one supporting
`
`clement cxtcnding in parallcl
`
`to a longitudinal axis of the shaft and provides for
`
`pivotable connection of the bone removal clementto the shaft.
`
`In some embodiments, the bone removal element is irremovably attached to the
`
`shaft by at least one of a hinge pin or said supporting element.
`
`In some embodiments,
`
`the bone removal element extends from the shaft upon
`
`rotation due to centrifugal force.
`
`In some embodiments,
`
`the bone removal element extends perpendicularly to a
`
`longitudinal axis of the shaft.
`
`In some embodiments,
`
`the device is adapted to operate in a bore drilling
`
`20
`
`configuration, having a rotation dircction in which the bone removal clement is in the
`
`closed position.
`
`In some embodiments,
`
`the device is adapted to operate in a bore widening
`
`configuration in which the bone removal element is in the open position. Optionally, the
`
`configuration is selected by selecting a direction ofrotation.
`
`25
`
`In some embodiments, the device is cannulated to be inserted over a guide wire.
`
`In some embodiments, the bone removal element extends at least 2 mm beyond
`
`the volume of rotation when in the open position.
`
`In some embodiments, the device is a reamer.
`
`In some embodiments, the device compriscs a plurality of cutting teeth.
`
`In some embodiments, the device comprises at least one structure configured for
`
`resisting further entry of the bone removal elementinto the shaft in the closed position.
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`WO 2014/174521
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`In some embodiments, the structure resisting further entry of said bone removal
`
`element into the shaft are one or more walls of arecess in the shaft in which the element
`
`is received.
`
`In some embodiments, the structure is an elastic element, allowing for the bone
`
`removal element to be pushed into the shaft and be fully concealed within the shaft.
`
`In some embodiments,
`
`the bone removal element is a cutting tooth, wherein at
`
`least a portion of the cutting tooth is large enough to actas the structure resisting further
`
`entry of the tooth into the shaft.
`
`10
`
`According to an aspect of some embodiments of the invention there is provided a
`
`bone material removal kit comprising an clongatcd shaft, a plurality of cutting teeth,
`
`includingafirst tooth attachable to the shaft, and a second different than the first tooth in
`
`at least aradial dimension, the second tooth attachable to the shaft, wherein when one of
`
`the teeth is attached to the shaft, the tooth is movable from an open position, in which it
`
`15
`
`extends radially away from the shaft, to a closed position; wherein whenthe first tooth is
`
`in a closed position,
`
`the first tooth is at least partially received within the shaft; and
`
`wherein when the second tooth is in the closed position,
`
`the second tooth is fully
`
`received within the shaft.
`
`In some embodiments, the first tooth is larger than the second tooth in at least a
`
`20
`
`radial dimension, so that it contacts side walls of a bore formed in the bone in the closed
`
`position.
`
`In some embodiments, the first tooth is configured for opening inside the bore in
`
`the bone, utilizing resistance of the walls acting on the tooth.
`
`In some embodiments, the second tooth is configured for opening outside a bore
`
`25
`
`in the bone, utilizing centrifugal force.
`
`According to an aspect of some embodiments there is provided a method for
`
`forming a bore in a bone, and widening at least a portion the bore, comprising: inserting
`
`a bone matcrial removal device comprising a cutting tooth into a bone, rotating the
`
`device inafirst direction to form a bore in the bone while at least a portion of the cutting
`
`tooth protrudes externally to a shaft of the device, the portion contacting bone tissue at
`
`the walls of the bore, when said device is advanced into the bore, reversing the rotation
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`WO 2014/174521
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`4
`direction of the device, utilizing resistance of the walls of the bore acting on the portion
`
`of the cutting tooth to open the tooth, pulling the device through the bore in a direction
`
`opposite the insertion direction, to widen at least a portion of the bore using the opened
`
`cutting tooth.
`
`In some embodiments, a diameter of the bore is defined by an extent in which the
`
`cutting tooth protrudes externally to the device when the tooth is in a closed position.
`
`In some embodiments,
`
`the method further comprises advancing the device
`
`through the bore until the cutting tooth exits the bone, and reversing a rotation direction
`
`to open the cutting tooth utilizing centrifugal force.
`
`In some embodiments,
`
`the method further comprises rotating the device in the
`
`first rotation dircction to close the tooth and remove the device from the widenedbore.
`
`In some embodiments,
`
`the method further comprises clearing removed bone
`
`material in front of the open cutting tooth by means of a curved cutting surface of the
`
`cutting tooth.
`
`In some embodiments, a diameter of the bore is widened by at least 30%.
`
`In some embodiments, the device is passed through an existing bore in a bone to
`
`widenit.
`
`In
`
`some
`
`embodiments,
`
`inserting comprises
`
`drilling. Optionally, drilling
`
`comprises drilling using a flexible shaft comprising at least a segment formed with a
`
`10
`
`15
`
`20
`
`spring.
`
`Unless otherwise defined, all technical and/or scientific terms used herein have
`
`the same meaning as commonly understood by one of ordinary skill in the art to which
`
`the invention pertains. Although methods and materials similar or equivalent to those
`
`25
`
`described herein can be used in the practice or testing of embodiments of the invention,
`
`exemplary methods and/or materials are described below. In case of conflict, the patent
`
`specification, including definitions, will control. In addition, the materials, methods, and
`
`examples are illustrative only and are not intended to be necessarily limiting.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Some embodiments of the invention are herein described, by way of example
`
`only, with reference to the accompanying drawings. With specific reference now to the
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`WO 2014/174521
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`5
`drawings in detail, it is stressed that the particulars shown are by way of example and for
`
`purposes ofillustrative discussion of embodiments of the invention. In this regard, the
`
`description taken with the drawings makes apparent to those skilled in the art how
`
`embodiments of the invention may be practiced.
`
`In the drawings:
`
`FIG. 1A-B show abone material removal device comprising an expandable distal
`
`tip shown in an open and closed configuration, according to some embodiments of the
`
`invention;
`
`FIG. 2A-F is a set of drawing showing an exemplary method for drilling a bore
`
`10
`
`in a bone, and widening at least a portion of the bore, according to some embodiments of
`
`the invention:
`
`FIG. 3 is a flowchart of an exemplary method for drilling a bore in bone, and
`
`widening at least a portion of the bore, according to some embodiments of the invention;
`
`FIG. 4 is a bone removal device comprising an expandable distal tip and a shaft
`
`15
`
`comprising a flexible portion, according to some embodiments of the invention;
`
`FIGs. 5A - 5B are two elevation views of a bone material removal device
`
`comprising an expandable distal tip, constructed according to another embodiment ofthe
`
`present invention, showing the expandable tip in a closed configuration;
`
`FIGs. 6A - 6B are two elevation views of the bone material removal device of
`
`20
`
`Figs. SA - 5B, showing the cxpandable tip in an cxpanded configuration, according to
`
`some embodiments of the invention;
`
`FIGs. 7A - 7B are two elevation views of a drill of the bone removal device of
`
`Figs. 5A - 6B, according to some embodiments of the invention;
`
`FlGs. 8A - 8D are a pictorial view and three different elevation views of a
`
`25
`
`cutting tooth of the bone removal device of Figs. 5A -
`
`6B, according to some
`
`embodiments of the invention;
`
`FIG. 9A is a pictorial view and an enlargement view of the bone material
`
`removal device of Figs. 5A -
`
`6B in a closed configuration, according to some
`
`cmbodiments of the invention;
`
`FIG. 9B is a pictorial view and an enlargement view of the bone material
`
`removal device of Figs. 5A - 6B in a partially open configuration, according to some
`
`embodiments of the invention;
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`6
`FIG. 9C is a pictorial view and an enlargement view of the bone material
`
`removal device of Figs. 5A - 6B in an expanded configuration. according to some
`
`embodiments of the invention;
`
`FIGs. 10A -
`
`IOC are a pictorial view, two sectional views and an enlargement
`
`view of the bone material removal device of Figs. 5A - 6B in a closed configuration,
`
`shown within a bone portion after a bore of a first diameter was drilled through the bone
`
`portion, according to some embodiments ofthe invention;
`
`FIGs. 11A - UC are a pictorial view and two sectional views of the bone
`
`material removal device of Figs. 5A - 6B in an expanded configuration, shown within a
`
`10
`
`bone portion after a bore of a first diameter was drilled through the bone portion,
`
`according to some cmbodiments of the invention;
`
`FIGs. 12A - 12B are two sectional views of the bone material removal device of
`
`Figs. 5A - 6B in an expanded configuration, shown within a bone portion when a bore
`
`of a second diameter was drilled partially through the bone portion, according to some
`
`15
`
`embodiments of the invention;
`
`FIGs. 13A - 13B are two sectional views of the bone material removal device of
`
`Figs. 5A - 6B shown within a bone portion, showing an additional method of use of the
`
`device, where a bore of a first diameter was drilled partially through the bone portion
`
`and the bone material removal device is shownin a closed configuration, according to
`
`20
`
`some cmbodiments of the invention;
`
`FIGs. 14A - 14B are two sectional views of the bone material removal device of
`
`Figs. 5A - 6B shown within a bone portion, showing an additional method of use of the
`
`device, where a bore of a second diameter was drilled partially through the bone portion
`
`and the bone material removal device is shown in an expanded configuration, according
`
`25
`
`to some embodiments of the invention.
`
`FIGs. 15A -
`
`I5B are two elevation views of a drill of a bone removal device
`
`similar to the bone removal device shownin Figs. 5A - 5B, constructed according to yet
`
`another embodiment ofthe present invention;
`
`FIGs. 16A - 16C are a pictorial vicw and two clcvation vicws of a cover of the
`
`bone removal device, according to some embodiments of the invention;
`
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`WO 2014/174521
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`PCT/IL2014/050381
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`4
`FIGs. 17A - 17D are a pictorial view and three different elevation views of a
`
`cutting tooth of the bone removal device, according to some embodiments of the
`
`invention;
`
`FIGs. 18A -
`
`18B are two elevation views and corresponding enlargements of a
`
`partial assembly of the bone removal device, showing the drill and the cover of the bone
`
`removal device;
`
`FIG. 18C is an elevation view, enlargement and a section view of a partial
`
`assembly of the bone removal device, showing the drill and cover of the bone removal
`
`device, according to some embodiments of the invention;
`
`10
`
`FIGs. 19A - 19B are two elevation views and corresponding enlargements of an
`
`asscmbled bone removal device, showing the expandable tip in a closed configuration,
`
`according to some embodiments of the invention;
`
`FIG. 19C is an elevation view, enlargement and a section view of the assembled
`
`bone removal device, showing the expandable tip in a closed configuration, according to
`
`15
`
`some embodiments of the invention;
`
`FIGs. 20A - 20C are three different elevation views and corresponding
`
`enlargements of the assembled bone removal device, showing the expandable tip in an
`
`expanded configuration, according to some embodiments of the invention;
`
`FIG. 21 is an exemplary bone material removal device comprising an extendible
`
`20
`
`cutting tooth, according to some cmbodiments of the invention;
`
`FIG. 22A-B are front views of a device comprising a cutting tooth for bone
`
`removal,
`
`showing a closed configuration of the cutting tooth (A) and an open
`
`configuration of the cutting tooth (B), according to some embodiments of the invention;
`
`FIG. 23 is a flowchart of a method for drilling a bore, and widening at least a
`
`25
`
`portion of the bore using a bone material removal device comprising a cutting tooth,
`
`according to some embodiments ofthe invention;
`
`FIG. 24A-B are cross sections of a shaft of a bone removal device showing an
`
`extendible cutting tooth, according to some embodiments of the invention:
`
`FIG. 25 is a front vicw of a bone removal device shown within a bore formed in
`
`the bone, according to some embodiments of the invention:
`
`FIG. 26A-E show a cutting tooth from various directions, according to some
`
`embodiments of the invention;
`
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`WO 2014/174521
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`8
`FIG. 27 illustrates a cutting tooth of a bone material removal device positioned
`
`against a bone surface,
`
`for example before widening a formed bore in the bone,
`
`according to some embodiments of the invention;
`
`FIG. 28 is an illustration of shaft of a bone material removal device comprising a
`
`hinge, according to some embodiments of the invention;
`
`FIG. 29A-C show an exemplary bone material removal device comprising a
`
`cutting tooth formed with a flat cutting face, according to some embodiments of the
`
`invention; and
`
`FIG. 30A-C illustrate a bone material removal device comprising a plurality of
`
`10
`
`cutting teeth, according to some embodiments ofthe invention.
`
`DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION
`
`The present
`
`invention in some embodiments thereof, relates to bone material
`
`removal tools, for example, tools in which an effective diameter of the tool is selectable.
`
`15
`
`An aspect of some embodiments of the invention relates to a bone material
`
`removal device comprising a shaft with an expandable distal portion.
`
`In some
`
`embodiments,
`
`the expandable distal portion comprises one or more bone removing
`
`elements, for example cutting or reaming teeth.
`
`In some embodiments,
`
`the device is
`
`adapted to operate in one of two operational configurations, for example one for drilling
`
`20
`
`and/or passing through a bore in a bone, and the other for widcning a bore in a bone. In
`
`some embodiments,
`
`the first configuration comprises cutting teeth at
`
`a closed
`
`configuration, such as contained within a shaft of the device. In some embodiments, the
`
`second configuration comprises cutting teeth at an open configuration,
`
`for example
`
`extending beyond the circumference ofthe shaft.
`
`25
`
`An aspect of some embodiments relates to a bone material removal device
`
`comprising a cutting tooth which is only partially received within a recess of a shaft of
`
`the device when the tooth is in the closed position.
`
`In some embodiments,
`
`the tooth extends beyond a periphery of the device, for
`
`cxample beyond a periphery of a shaft portion configured directly above and/or bclow
`
`the recess in which the tooth is received. In some embodiments, a least a section of the
`
`shaft defines a generally cylindrical volume of rotation, and at least a portion of the
`
`closed tooth extends beyond the volumeof rotation. In some cases, a diameter of a bore
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`WO 2014/174521
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`9
`formed using the device is defined by an extent in which the tooth protrudes externally
`
`to the shaft of the device.
`
`In some embodiments,
`
`the tooth is moved to an open position by utilizing
`
`resistance of the walls of the bore acting on the protruding portion of the tooth.
`
`Optionally, pivoting of the tooth is actuated by reversal of rotation direction of the
`
`device, creating friction between the protruding portion of the tooth and the walls of the
`
`bore. Alternatively,
`
`for example in cases in which the device is inserted into a pre-
`
`formed bore in the bone,
`
`simply rotating the device (such as without
`
`reversing a
`
`direction of rotation) would open the tooth.
`
`Additionally or alternatively,
`
`in some embodiments,
`
`the tooth is advanced passed
`
`the bore to exit the bone, and pivoting of the tooth is actuated by reversal of rotation
`
`direction, utilizing centrifugal force to open the tooth.
`
`In some embodiments,
`
`the recess in the shaft, in which a portion of the tooth is
`
`received,
`
`is shaped and/or sized to limit movement of the tooth,
`
`such as rotational
`
`movement,
`
`for example preventing
`
`over-opening
`
`and/or over-closing
`
`the
`
`tooth.
`
`Additionally or alternatively,
`
`a hinge by which the tooth is coupled to device is
`
`configured for limiting movement of the tooth, for example by comprising one or more
`
`transversely extending projections.
`
`In some embodiments,
`
`the hinge is a rod hinge, comprising elongated proximal
`
`and/or distal extensions
`
`that are received within a shaft of the device. A potential
`
`advantage of a hinge comprising elongated extensions may include reducing a risk of
`
`disengagement of the hinge from a shaft of the device.
`
`An aspect of some embodiments
`
`relates to a bone cutting tooth comprising a
`
`cutting face formed with a curvature.
`
`In some embodiments,
`
`at least a portion of the
`
`cutting face is concave. Additionally or alternatively,
`
`a portion of the cutting face is
`
`planar.
`
`In some embodiments, a curved cutting surface such as a concave cutting surface
`
`is effective to distribute force applied onto the cutting face by the bone tissue that is
`
`being cut. Optionally,
`
`the concavity is non-symmetrical,
`
`for example along a height of
`
`the tooth. Alternatively,
`
`the concavity is symmetrical.
`
`In some cases,
`
`the concavity of
`
`the cutting face acts as flute, providing a path for removal of the removed bone material,
`
`including,
`
`for example, bone chips and/or dust. In some cases, removed bone material
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`flows towards a center of the concavity, and then flows in the proximal and/or distal
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`directions over the top and/or bottom surfaces of the cutting tooth.
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`In some cases,
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`removed bone material exits through a first and/or second openings of the formed bore.
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`Additionally or alternatively,
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`removed bone material
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`is swept by the cutting face
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`towards the walls of the bore.
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`In some embodiments, a bottom surface of the cutting tooth facing a generally
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`proximal direction is formed with a curvature and/or an inclination, for engaging an
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`irregular bone surface,
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`for example before the opened cutting tooth is pulled back
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`through the bore to widen at least a portion of the bore.
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`In some embodiments, a back wall of the tooth, such as a generally opposite wall
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`to the cutting facc, compriscs a rounded gcomctry so that it is at lcast partially flushed
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`with the shaft when the tooth is in a closed configuration. In some embodiments,
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`the
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`back wall is curved, and does not inflict resistance to rotation of the shaft when the tooth
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`is closed, for example by smoothly sliding across the walls of the bore during rotation of
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`the shaft.
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`In some embodiments,
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`the tooth is rigid.
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`In some embodiments,
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`the tooth is
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`elastic enough so that the protruding portion of the tooth is pushed into the recess in the
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`shaft during formation of the bore. Optionally, when the rotation direction changes, the
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`protruding portion immediately bounces out of the shaft, contacting the walls of the bore
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`which thereby initialize the opening of the tooth. Optionally, the tooth continucs to pivot
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`to a fully open configuration as rotation continues and increasing resistance is applied to
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`the tooth by the walls of the bore.
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`In some embodiments, a portion of the tooth, such as a cutting surface of the
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`tooth, is formed of a rigid material. Additionally or alternatively, a portion of the tooth,
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`for example a back wall, is formed of a flexible material.
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`In some embodiments, the cutting tooth comprises one or more slots or channels,
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`for example the cutting face may be formed with a radially extending slot,
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`through
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`which removed bone material can pass to be cleared away from tooth.
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`In some embodiments,
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`the cutting teeth extend from the distal tip, for example
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`extending substantially perpendicularly to the longitudinal axis of the device. Optionally,
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`a cutting tooth pivots to an open position, in which it extends radially away from the
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`In some embodiments, expanding the distal portion includes enlarging a radius
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`device.
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`of the bone engaging portion of the device. In some embodiments, the device includes a
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`forward drill bit.
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`In an exemplary embodiment of the invention,
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`the bone removal elements are
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`attached to the shaft freely enough so that rotation of the shaft at sufficient speed would
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`cause them to extend radially outwards from a position they are in, for example from a
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`position in which the elements are flush with the shaft or a position in which the
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`elements are recessed from the shaft. In an exemplary embodiment, the shaft includes a
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`stop which prevents over extension of the elements,
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`for example, limiting the rotation of
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`the clements around a hinge which attaches them to the shaft
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`to an angle ranging
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`between, for example, 50,70, 80, 90, 100 or smaller or intermediate or greater number
`
`degrees.
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`In some embodiments, a stopping element is configured to restrict entry of a
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`cutting element further into the shaft, for example when the cutting element is in a
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`closed position.
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`In some embodiments,
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`the stopping element comprises one or more
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`walls of a recess in the shaft in which the bone removal element is received. In some
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`embodiments,
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`the stopping element
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`is the cutting element
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`itself, for example being
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`formed with a portion large enough to prevent the cutting element from fully entering
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`the shaft. In an cxample, a radial cxtcnt of a cutting clementis larger than that of the
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`shaft, preventing from the complete cutting element to be fully contained within the
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`shaft.
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`In some embodiments, the stopping element comprises an elastic element such as
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`a spring coupled to the tooth and/or the shaft, which allows for the cutting element to be
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`pushed into the shaft. Optionally, the spring provides for the cutting element to bounce
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`open, for example to form contact between the cutting element and the walls of the bore
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`in the bone. Optionally, friction is created between the cutting element and the walls,
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`actuating initial opening or further opening ofthe tooth.
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`In some embodiments,
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`the operational configuration is selected by a user. In
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`some cmbodiments, changing the dircction of rotation causes the cutting tecth to extend,
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`such as by pivoting to an open configuration, or alternatively to fold back into a closed
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`configuration. For example, this may be provided by the relative locations of a center of
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`gravity of the tooth and a hinge (e.g. an axial pin) connecting the tooth to the shafi. In
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`some embodiments, centrifugal force created during the rotation of the device thrusts the
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`cutting teeth outwardly from the shaft of the device.
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`In some embodiments,
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`rotation causes extension, obtained for example by
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`pivoting of a tooth with respect to a shaft of the device, until reaching a stop. However,
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`the teeth may be free to move back to a previous position. In such a case, the extension
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`(such as by pivoting) of the teeth will depend on the direction of rotation and existence
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`of nearby objects, such as bone,
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`to contact the teeth. Rotation in a first direction will
`
`cause the teeth to engage the bone, and the stop will prevent the teeth from moving out
`
`of the way, ultimately resulting in bone removal. A rotation in opposite direction allows
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`the tooth to retreat from the force applied by the bone, and possibly fold back to become
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`flush with the shaft.
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`In some embodiments,
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`the device can be seen as having two behaviors,
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`depending on the drilling direction. In one drilling direction, contact of extended teeth
`
`with objects such as bone will tend to close the teeth, and in the other drilling behavior
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`the teeth, when contacting bone, will tend to remain in an extended position and remove
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`bone material.
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`In some embodiments, an initial bore is drilled in a bone. In some embodiments,
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`after the initial bore is drilled, the device is used for widening at least a portion of the
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`bore.
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`In some embodiments, by reversing the direction of rotation of the device, the
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`cutting tecth are pushed outward.
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`In one cxamplc, when the device is rotated in a
`
`clockwise direction the cutting teeth are maintained within the circumference of the shaft
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`of the device, and when the device is rotated in a counterclockwise direction the teeth
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`extend outwardly from the shaft. Optionally,
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`the centrifugal
`
`force created once the
`
`direction of rotation is reversed is strong enough to thrust the cutting teeth outwards.
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`In some embodiments,
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`the shaft of the device comprises a flexible portion, for
`
`example comprising a spring.
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`An aspect of some embodiments relates
`
`to a bone material
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`removal kit,
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`comprising a device for example as described herein, and a plurality of replaceable
`
`cutting teeth. In some cmbodiments, the cutting tecth include a first tooth which is only
`
`partially received within a shaft of the device, and a second tooth which is fully received
`
`within a shaft of the device. In some embodiments, at least a portion of the first tooth, in
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`a closed position, contacts walls of the bore in the bone,
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`to provide for friction based
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`opening of the tooth when the device is inside a bore in the bone. In some embodiments,
`
`the second tooth is moved to an open configuration as a result of rotation, for example
`
`due to centrifugal
`
`force. Optionally, a user selects the first tooth when opening of the
`
`tooth inside the bore is desired, and selects the second tooth when opening of the tooth
`
`outside the bore is desired. In some embodiments,
`
`the tooth is configured as a part of a
`
`unit, for example including a shaft segment which can be assembled onto the device.
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`Figure
`
`1A-B shows
`
`a bone material
`
`removal device
`
`101
`
`comprising an
`
`expandable distal portion 103, according to some embodiments of the invention. An
`
`enlarged view of distal portion 103 of figure 1A and of figure IB is shown under each.
`
`In some embodiments,
`
`the device comprises a distal tip 105, a shaft 107, and a
`
`proximal end 109.
`
`In some embodiments, a distal portion 103 of the device comprises a plurality of
`
`bone removal elements such as cutting teeth 111, for example 1, 2,5, 8 or any larger or
`
`intermediate numbers. In some embodiments,
`
`the cutting teeth 111 extend from shaft
`
`107 of the device. In some embodiments, as will be further explained, centrifugal force
`
`caused by rotation of the device acts on the cutting teeth to extend them.
`
`In some embodiments,
`
`the device is adapted to two operational configuration