Cortical bone particle scraper and collector tool

Abstract

A cortical bone particle scraper and collector tool (10) comprising: - a handle (20) provided with a handgrip (21); - a collection chamber (25) elongated along a longitudinal axis (A); - a stem (30) at least partially arranged inside the collection chamber; - a blade (40) attached to a distal end of the stem (30); and - a passage opening (50) defined between a rear face of the blade and a distal end of the collection chamber to allow the introduction of bone particles scraped by the blade into the collection chamber, wherein a distal end of the stem is configured to be inserted into the distal end of the collection chamber, defining therewith a shape constraint so that, in use, the blade only has a degree of freedom to slide axially along a direction parallel to the longitudinal axis of the collection chamber due to elastic elongation of the stem.

Description

[0001] CORTICAL BONE PARTICLE SCRAPER AND COLLECTOR TOOL

[0002] TECHNICAL FIELD

[0003] The present invention relates to bone tissue reconstructive and regenerative removal techniques in orthopaedic oro-maxillofacial, plastic, periodontal and implant surgery as well as bone plastic techniques.

[0004] More particularly, the present invention relates to a surgical tool for scraping and collecting bone particles, i.e. bone shavings or chips / flakes, which can be used in such tissue regeneration techniques.

[0005] PRIOR ART

[0006] There are various tools for scraping and collecting bone particles, so-called “cortical bone collectors".

[0007] A well-known example of such tools is described in international patent application no. WO2022149060 by the same Applicant.

[0008] A need perceived in the industry is to increase the uniformity and repeatability of the scraping and collecting of cortical bone, without these operations being affected by the forming process and / or shape of the tool.

[0009] In particular, a perceived need is that all the tools (the same as one other) actually exhibit the same scraping response and performance characteristics and thus each product can exhibit technically predictable, uniform and precise technical and performance characteristics.

[0010] DISCLOSURE OF THE INVENTION

[0011] An object of the present invention is to solve these needs (and other needs that will become clear below) of the prior art, with a simple, rational and cost-effective solution. Such aims are achieved by the characteristics of the invention reported in the independent claims. The dependent claims outline preferred and / or particularly advantageous aspects of the invention.

[0012] The invention, in particular, makes available a cortical bone particle scraper and collector tool comprising:

[0013] - a handle provided with a handgrip;

[0014] - an elongated collection chamber along a longitudinal axis;

[0015] - a stem at least partially arranged inside the collection chamber;

[0016] - a blade attached to a distal end of the stem; and- a passage opening defined between a rear face of the blade and a distal end of the collection chamber to allow the introduction of bone particles scraped by the blade into the collection chamber,

[0017] wherein a distal end of the stem is configured to be inserted into the distal end of the collection chamber, defining therewith a shape constraint so that, in use, the blade only has a degree of freedom to slide axially along a direction parallel to the longitudinal axis of the collection chamber due to elastic elongation of the stem.

[0018] This configuration provides an appropriate, predictable and repeatable result in cortical bone scraping due to the correct elastic response of the stem. In fact, the elastic response depends only on the tensile modulus of the stem, not on the bending modulus, guaranteeing constant and predictable / predefinable performance at the design stage in all tools made in this way.

[0019] According to an aspect of the invention, the stem can be obtained by injection moulding of a plastic material.

[0020] The injection moulding process of the stem allows precise control of its technical and elastic properties, ensuring uniform scraping characteristics across multiple devices. In a further aspect, a spacer can be interposed between the rear face of the blade and the distal end of the collection chamber to define the passage opening.

[0021] Thanks to this solution, the construction of the surgical tool, e.g. of the passage opening thereof, and its functionality is particularly improved compared to known surgical tools, as the collection chamber (i.e. the cannula that defines it) does not require any special processing or adaptation, but can be made simply and quickly.

[0022] For example, the distal end of the collection chamber can be planar and free from steps or notches, allowing faster, cheaper and more accurate manufacturing.

[0023] Advantageously, the spacer can be made in one piece with the stem at its distal end. This makes it possible to simplify the tool assembly and forming operations, while increasing the tool repeatability performance.

[0024] Again, the spacer may comprise at least one rear tang (or axial section) adapted to be threaded substantially axially into the distal end of the collection chamber, defining the aforementioned shape constraint therewith.

[0025] Thanks to this, the above-mentioned effects can be achieved easily, cheaply and effectively.Preferably, the spacer, i.e. its axial section, has an asymmetrical outer perimeter comprising:

[0026] - a semi-circular annular body (or portion) configured to define a contact portion intended to make contact with the distal end of the collection chamber, and

[0027] - a recess adapted to be radially separated from the distal end of the collection chamber so as to define a passage channel connecting the passage opening with the inside of the collection chamber.

[0028] This asymmetrical design of the spacer optimises the process of collecting bone particles by creating a well-defined passage opening while maintaining adequate contact with the collection chamber (and thus allowing the stem to elongate without bending).

[0029] The passage opening may be delimited, in an axial direction, by a portion of a scraping edge of the blade and by a circumferential portion of the distal end of the collection chamber and, in a circumferential direction, by the recess of the spacer.

[0030] This specific configuration of the passage opening ensures efficient collection of bone particles while maintaining the structural integrity of the tool.

[0031] Advantageously, the distal end of the collection chamber can be planar and free of steps or notches.

[0032] A planar distal end simplifies and economises the production and cleaning processes of the tool.

[0033] In an embodiment of the tool, the collection chamber can be curved (with a single curve), in which case the stem is moulded directly into a curved shape (with a corresponding single curve) during the injection moulding process (adapting to the curved longitudinal extension of the collection chamber).

[0034] By making the stem directly in a curved shape (and not bending a straight stem to achieve the desired curvature), it is possible to further standardise the response of the various tools produced, thus allowing a high degree of predictability and uniformity in the various production batches.

[0035] In addition, the adaptation of the curvature of the stem to the collection chamber ensures the correct functionality of the entire tool, while maintaining the expected performance characteristics.

[0036] In an alternative embodiment, the collection chamber can be rectilinear and the stem can consequently be moulded directly into a rectilinear shape during the injection mouldingprocess.

[0037] According to a further aspect of the invention, the distal end of the stem may comprise a housing seat, the blade comprising an anchoring root inserted by interference into the housing seat.

[0038] This direct insertion method simplifies assembly and reduces the need for additional fastening components, potentially reducing production costs and improving reliability.

[0039] Advantageously, the distal end of the stem and / or blade can comprise an angular reference body to determine a precise and predetermined blade orientation.

[0040] The use of the angular reference body ensures the correct orientation of the blade, which can lead to more efficient and uniform collection of bone particles.

[0041] In addition, the angular reference body allows the use of specialised blades, such as the “volumising” blades, in this type of cortical bone collector, expanding its versatility and potential applications.

[0042] In particular, the blade (of the “volumising” type) comprises a plurality of mutually separate cutting edges.

[0043] Advantageously, the collection chamber and stem can be mutually movable between:

[0044] - a collection position, in which the spacer is in contact with the distal end of the collection chamber and the collection chamber is only accessible from the outside via the passage opening defined by the spacer, and

[0045] - a discharge position, in which the spacer is separated from the distal end of the collection chamber.

[0046] This movable configuration allows efficient collection of bone particles during use and easy discharge of the collected material after the process, improving the overall functionality of the tool.

[0047] Moreover, according to a further aspect of the invention, the tool may comprise a locking element configured to temporarily lock the stem and the collection chamber at least in the collection position.

[0048] The locking element ensures stability during the bone particle collection process, preventing unwanted movement between the stem and the collection chamber.

[0049] The invention also makes available a method of manufacturing a cortical bone particle scraper and collector tool as described above comprising the steps of:

[0050] - injection moulding a plastic material to form a stem with a distal end configured toadapt to the collection chamber (possibly by shaping - in the same injection moulding process - the stem with a pre-curvature if the collection chamber is curved); - possibly injection moulding a handle provided with a handgrip and forming a collection chamber (open at its distal end);

[0051] - inserting a blade by interference coupling into a seat at the distal end of the stem; - assembling the stem inside the collection chamber so that a passage opening for the bone particles remains defined between the blade and a distal end of the collection chamber.

[0052] Thanks to this solution, it is possible to make a tool as described above with the above-mentioned advantages.

[0053] This method provides a standardised and repeatable approach for making tools for the collection of cortical bone particles and, thus, enables the standardisation of cortical bone collection, potentially improving consistency and efficiency in bone particle collection processes.

[0054] A further aspect of the invention makes available a method for collecting cortical bone particles using the tool described above. The method involves positioning the blade against a bone surface; applying pressure to the handle to make the blade scrape the bone surface; and collecting bone particles through the passage opening into the collection chamber.

[0055] BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Further features and advantages of the invention will be more apparent after reading the following description provided by way of a non-limiting example, with the aid of the accompanying drawings.

[0057] Figure 1 is a side view of an embodiment of a tool according to the invention.

[0058] Figure 2 is a longitudinal sectional view of Figure 1.

[0059] Figure 4a is an enlarged detail of Figure 2.

[0060] Figure 3 is a front axonometric view of Figure 1.

[0061] Figure 4 is a side view of a further embodiment of a tool according to the invention. Figure 5 is a longitudinal sectional view of Figure 4.

[0062] Figure 4a is an enlarged detail of Figure 5.

[0063] Figure 6 is a front axonometric view of Figure 4.BEST MODE TO IMPLEMENT THE INVENTION

[0064] With particular reference to these figures, the reference number 10 has been used to indicate overall a cortical bone particle scraper and collector tool, such as a hand tool, configured to scrape and collect cortical bone particles, i.e. shavings or chips / flakes of bone.

[0065] In this disclosure, the terms “lower” and “upper” are used in the present description referring to the position of the tool 10 in the use configuration, wherein “lower” means facing the bone to be scraped and “upper” means facing the part opposite the bone to be scraped.

[0066] Furthermore, the terms “front” or “distal” and “rear” or “proximal” have been used in the present description referring to the position of the tool 10 with respect to the hand holding the tool, wherein “front” or “distal” means in a position furthest from the palm of the user's hand and “rear” or “proximal” means in a position closest to the palm of the user's hand. The tool 10 comprises a handle 20 that can be held (at the rear) by an operator.

[0067] The handle 20 has an elongated body provided with a longitudinal axis A .

[0068] For example, the opposite axial ends of the handle 20 are open.

[0069] The handle 20 comprises, at the rear, a handgrip 21 adapted to be held by one hand of the operator and an opposite distal end is free.

[0070] A proximal end of the handgrip 21 defines the proximal end of the handle 20.

[0071] The handle 20 also comprises a cannula 22, which is attached at the front to the handgrip 21.

[0072] The cannula 22 axially extends the handgrip 21 (in the front direction).

[0073] A distal end of the handgrip 21 defines the distal end of the handle 20.

[0074] The cannula 22, in particular, has a proximal end fixed, for example snap-fitted or screwed or welded or otherwise, to the distal end of the handgrip 21 and a free opposite distal end. The cannula 22, for example, has a constant transversal section (orthogonal to the longitudinal axis A) throughout its longitudinal extension.

[0075] For example, the cannula 22 has an inner chamber 220, which is substantially cylindrical (the term “cylindrical” meaning that its cross section may be circular, as in the preferred example shown, or of any other shape).

[0076] The inner chamber 220 of the cannula 22 is axially extended in a rearward direction from an inner cavity of the handgrip 21, for example having the same shape and size as theinner chamber 220 of the cannula 22.

[0077] In practice, the handle 20 defines as a whole a hollow body having an axial cavity formed by the inner cavity of the handgrip 21 and the inner chamber 220 of the cannula 22. In the example shown, the cannula 22 and the handgrip 21 are made of two separate bodies, but it is not excluded that they can be made as a single body.

[0078] In a first embodiment shown in Figures 1 and 3, the cannula 22 has a rectilinear portion, proximal to the proximal end (and ending at the rear therewith) of the cannula itself, which has a rectilinear (coaxial) longitudinal axis, and a curved portion, proximal to the distal end of the cannula 22 (at a non-zero distance from it), which has a curved longitudinal axis (e.g. according to an arc of a circle).

[0079] In such a first embodiment, the cannula 22 also has a further rectilinear portion, proximal to the distal end of the cannula itself (and terminating at the front therewith), which has a rectilinear (coaxial) longitudinal axis, tilted (at the top) with respect to the longitudinal axis of the rectilinear portion by an angle substantially between 20° and 40°, for example equal to 27°.

[0080] In practice, the curved portion of the cannula 22 is axially interposed between the rectilinear portion and the further rectilinear portion.

[0081] For example, the curvature of the cannula 22 is such that it curves at the top the distal end of cannula 22, i.e. it has an upper intrados and a lower extrados.

[0082] In a second embodiment shown in Figures 4 and 6, the cannula 22 has a (totally) rectilinear longitudinal axis.

[0083] The distal end of the cannula 22, i.e. of the handle 20, is (completely) planar (and free from steps or notches).

[0084] The cannula 22 internally delimits a collection chamber 25, which is defined near the distal end thereof.

[0085] In particular, the distal end of the cannula 22 coincides with the distal end of the collection chamber 25.

[0086] The collection chamber 25 is defined internally by a distal portion of the inner chamber 220 of the cannula 22, i.e. it is delimited perimetrically by the (perimeter wall of) the cannula 22 and at the front by the distal end of the cannula 22 itself.

[0087] The collection chamber 25 has, as will be better described hereinafter, a variable volume, e.g. it has a proximal end which is (axially) movable with respect to the distal end.The surgical tool 10 further comprises a stem 30, which is housed, at least partially, inside the handle 20, i.e. the handgrip 21 and / or the cannula 22.

[0088] The stem 30 is defined by an elongated body along a longitudinal axis B and is axially inserted inside the handle 20 (i.e. of the handgrip 21 and / or the cannula 22).

[0089] The stem 30 has a rear end 31 , which - for example - protrudes from the proximal (open) end of the handle 20, i.e. of the handgrip 21 , and an opposite front end 32 arranged near the distal end of the handle, i.e. of the cannula 22.

[0090] For example, (also) the front end 32 of the stem 30 is configured to protrude (or at least partially protrude) from the distal (open) end of the handle 20.

[0091] The stem 30 comprises at least one front end section, provided with the front end 32 thereof, which is adapted to be contained within the collection chamber 25, with abundant radial clearance.

[0092] In practice, the collection chamber 25 is defined by a radial portion of the inner chamber 220 of the cannula 22 interposed between the (inner wall of the) cannula 22 and (the outer wall of the front end section of) the stem 30.

[0093] Moreover, the stem 30 has an enlarged rear section, which terminates at the rear with a grip portion (again) defined externally at the rear of (the handgrip 21 of) the handle 20 and provided with the rear end 31.

[0094] The grip portion of the stem 30 is, for example, ergonomically shaped to be easily gripped by the (fingers of a) user.

[0095] The rear enlarged tract of the stem 30 is radially housed to measure in the inner cavity 210 of the handgrip 21 (and / or at least one axial section of the inner chamber 220 of the cannula 22).

[0096] On the front end section of the stem 30 there is a shutter disc 33, which is housed to measure inside the inner chamber 220 of the cannula 22, so as to occlude the collection chamber 25 (at the rear).

[0097] In practice, the collection chamber 25 is perimetrically / radially delimited by the (inner wall of the) cannula 22 and at the rear by the shutter disc 33 of the stem 30, while it is open at the front at the distal end of the cannula 22 (i.e. of the handle 20).

[0098] For example, the stem 30, e.g. at least or only its front end section (except for the shutter disc 33), is elastically extensible (preferably elongatable), i.e. it is configured to be tensile deformed, without being plastically deformed, and independently return elastically to itsundeformed configuration.

[0099] For example, the stem 30, i.e. the front end section only (with the exception of the shutter disc 33 and the spacer described below) thereof, has a tensile modulus (also called Young’s modulus) comprised between 2000 Mpa and 5000 Mpa, preferably 3000 Mpa, preferably an elongation at break due to tensile stress greater than 15%.

[0100] The stem 30 (preferably in a single piece) is for example made of a plastic material. Preferably, the stem 30 is obtained by injection moulding plastic material.

[0101] When the stem 30 is used in a straight collection chamber 25 (such as the one illustrated in Figures 4-6) the stem 30 is moulded directly into a straight shape during the injection moulding process.

[0102] When the stem 30 is used in a curved collection chamber 35 (such as the one illustrated in Figures 1-3) the stem 30 is moulded directly into a curved shape during the injection moulding process.

[0103] In other words, the stem 30 has no (flexural) pre-tension in its state of use.

[0104] The tool 10 further comprises a blade 40 configured to scrape bone particles, e.g. in the form of bone shavings or chips / flakes.

[0105] The blade 40 is supported by the stem 30, near the front end 32 thereof, as will be better described below.

[0106] The blade 40 has a rigidity (which is high, i.e. greater than the rigidity of the bone) such that it does not resonate during the scraping operation it is subjected to.

[0107] The blade 40 is generally made of metal, preferably stainless steel.

[0108] For example, the blade 40 is attached, preferably permanently, to the front end 32 of the stem 30.

[0109] The blade 40 is (prevalently) arranged outside the handle 20 (i.e. the cannula 22 thereof). In practice, the blade 40 is arranged at the front of the distal end (of the cannula 22) of the handle 20.

[0110] The blade 40 protrudes radially from the stem 30, for example by a radial section having substantially the same width as the width of the collection chamber 25.

[0111] The blade 40 comprises a cap 41 provided with a sharpened (radial) scraping edge 410, for example facing downwards.

[0112] The scraping edge 410 (globally) has a circumferential or semi-circular longitudinal extension.The scraping edge 410 is a free edge (in use) of the blade 40, i.e. protruding from the handle 20 (either axially or radially) or otherwise not in contact with it or with other elements of the tool 10, preferably facing downwards with respect to the handle 20.

[0113] In the embodiment shown in Figures 1 to 3 (in which the cannula 22 / collection chamber 25 has a curved shape), the scraping edge 410 is arranged radially outwards from the extrados part of the curvature assumed by the cannula 22.

[0114] In a first embodiment of the blade 40 (see Figures 1 -6), it is essentially continuous or has a single semi-circular cutting edge.

[0115] In a second embodiment of the blade 40 (see hatching in Figure 3), it may be of the “volumising” type, i.e. it may comprise a plurality of cutting edges, e.g. two or more cutting edges, separated from each other, i.e. spaced by a non-zero distance, by an empty gap (or, at most, non-scraping / unsharpened).

[0116] In practice, in this case, the scraper edge 410 is divided into a plurality of (circular) sectors, each of which defines a respective cutting edge.

[0117] Each cutting edge consists of or is defined by or comprises a sharpened apical end (or vertex, downward-facing) of the 410 contoured edge and has a curved longitudinal extension along a (circular) portion of the arc of a circle (defined by the circumferential longitudinal extension of the scraping edge 410).

[0118] Preferably, the blade 40 comprises at least one recess (i.e., an axially drilled through recess in the blade 40, particularly in the cap 41 thereof that intercepts and interrupts the scraper edge 410), which is interposed between two (adjacent) cutting edges, and thus separates them.

[0119] The hollow is defined by an open gap at the bottom, e.g. longitudinally shaped with a radial longitudinal axis.

[0120] The length of the notch is (much) less than the diameter of the blade 40, in particular, it extends over a limited section of the cap (i.e. over a small end portion of the cap less than its entire area and / or less than its diameter).

[0121] For example, the length of the notch is comprised between 0.1 mm and 1 mm, preferably 0.3 mm.

[0122] The (circumferential) width of the notch, which corresponds to the (non-zero) distance between the cutting edges of the blade 40, is comprised between 0.01 mm and 1 mm, preferably comprised between 0.01 mm 0.2 mm, e.g. advantageously 0.05 mm.Thanks to this small distance between the cutting edges, it is possible to maximise the amount of bone removed with each step (generating large chips) while at the same time achieving reduced bulging of the scraped bone and increasing the effectiveness of the tool 10.

[0123] The blade 40 comprises a rear (or scraping) face, substantially planar, facing backwards (i.e. , towards the distal end of the handle 20 and / or the cannula 22).

[0124] The rear face is substantially orthogonal to the longitudinal axis B of the stem 30, or at least of a section thereof proximal to its front end to which the blade 40 is attached. The blade 40 further comprises a fastening tang 43, for example cylindrical or prismatic, which is derived from the cap 41 (in a single piece therewith), for example from the rear face thereof, with its axis orthogonal to the rear face.

[0125] The fastening tang 43 is configured to be firmly and rigidly fastened to the front end 32 of the stem 30, for example by remaining firmly engaged thereon without any possibility of movement.

[0126] The fastening tang 43, for example, comprises a (peripheral) serration, e.g. conical, configured to abut / engage in the front end 32 of the stem 30, as described below.

[0127] For example, the front end 32 of the stem 30 comprises a housing seat 320 configured to house by interference the fastening tang 43 of the blade 40 retaining it.

[0128] The housing seat 320 is, for example, cylindrical or conical (open at the front end 32 and closed at the opposite end) with its axis parallel to the longitudinal axis B of the stem 30 (i.e. the section of the stem in which it is made).

[0129] The fastening tang 43 of the blade 40 is fastened to the housing seat 320 of the stem 30 by interference fit.

[0130] The tool 10, in particular the stem 30 thereof, further comprises a spacer 35, which is configured to be interposed between the rear face of the blade 40 and the distal end of the collection chamber 25 (i.e. of the cannula 22).

[0131] The spacer 35 is made in a body separated from the blade 40 and the cannula 22 (and / or from the collection chamber 25).

[0132] Preferably, the spacer 35 is made in one piece with the stem 30 (and defines its front end 32).

[0133] In particular, the spacer 35 defines an enlarged body of the stem 30 (having an overall diameter substantially greater than or equal to the overall diameter of the distal end of thecollection chamber 25.

[0134] The spacer 35, overall, is such that it (enters axially and) partially occludes the distal end of the collection chamber 25 leaving (open only) a lower passage opening 50 for introducing the bone particles scraped by the blade 40 into the collection chamber 25.

[0135] Such passage opening 50 is obtained by keeping at a distance, for at least a lower circumferential tract of the spacer 35, the lower portion of the rear face of the blade 40 (provided with the scraping edge 410) from the (lower portion of) distal end of the collection chamber 25.

[0136] The spacer 35 is provided with a first (front) face 351 facing the blade 40 and in contact with the rear face thereof and an opposite second face 352 facing the distal end of the collection chamber 25 (and the cannula 22), of which an upper circumferential contact portion (lower than its entire circumferential perimeter) is intended to contact it.

[0137] In practice, the contact portion is configured to contact the distal end of the collection chamber 25 by closing (at the top) the latter (as will be better described hereinafter). The spacer 35 is substantially shaped like a collar (crossed axially by the housing 320), having a front annular body 353 (which remains external to the collection chamber 25 and which has the first face 351 and second face 352 and their contact portion) and a rear tang 354 which fits axially into the distal end of the collection chamber 25,

[0138] The outer perimeter of the spacer 35, moreover, is provided with a (lower) recess, having a radial dimension smaller than the radial dimension of the circular portion, which is adapted to be radially separated from the distal end of the collection chamber 25 (when the contact portion defined in the annular body 353 is in contact with the distal end of the collection chamber 25 itself).

[0139] The passage opening 50 is, in practice, delimited:

[0140] - in the axial direction, at the front, by a (lower) portion of scraping edge 410 of the blade 40 and, at the rear, by a circumferential (lower) portion of the distal end of the collection chamber 25 (facing and at a non-zero distance from the scraping edge 410 of the blade 40); and

[0141] - in the circumferential direction by the recess of the spacer 35.

[0142] The axial width of the passage opening 50 is, substantially, equal to the axial thickness of the spacer 50 (at the annular body 53, i.e. of the contact portion thereof).

[0143] The circumferential width of the passage opening 50 is substantially equal to the (angular)width of the recess.

[0144] The distal end of the stem 30, in particular, the rear tang 353 of the spacer 35, is configured to be inserted into the distal end of the collection chamber 25, defining therewith a shape constraint so that, in use, the blade 40 only has a degree of freedom to slide axially along a direction parallel to the longitudinal axis A of the collection chamber 25 due to elastic elongation of the stem 30.

[0145] In practice, the maximum radial dimension of the rear tang 353 is substantially equal to the inner diameter of the collection chamber 25, so that it is inserted within it substantially to size, when the second face 352 of the spacer 35 is in contact (by its contact portion) with the distal end of the collection chamber 25 itself.

[0146] When the second face 352 of the spacer 35 is in contact (by its contact portion) with the distal end of the collection chamber 25 itself, the rear tang 353 has an outer (semi-)cylin-drical (upper) surface resting on a corresponding inner (upper) (semi-)cylindrical surface of the collection chamber 25, which acts as a radial abutment for the stem 30 (and for the blade 40) preventing it from bending and / or lifting during scraping operations of the blade 40 on the bone.

[0147] The rear tang 353, for example, has a decreasing radial thickness from the second face 353 towards the inside of the collection chamber 25, defining a guide ramp.

[0148] Advantageously, the distal end of the stem 30 and / or the blade 40 comprises an angular reference body to determine a precise and predetermined angular orientation of the blade 30 (with respect to the longitudinal axis B of the blade 30).

[0149] In particular, the distal end of the stem 30, defined by the first face 351 of the annular body 353 of the spacer 35, has a step that separates the first face in a lowered bottom plane from an upper raised plane (distal from the cutting edge of the blade 40).

[0150] The step has a rectilinear profile having an axis orthogonal to the longitudinal axis B of the stem and parallel to a plane tangent to (the lower end of) the cutting edge of the blade 40.

[0151] The blade 40 (i.e. its cap 41), for example, has a flat top cut, which is configured to abut and reference on the aforementioned step, thus allowing for a unique reciprocal orientation between the blade 40 and the stem 30, in which (the lower) cutting end of the blade 40 is arranged in a predetermined angular position with respect to the stem 30 and, therefore, with respect to the distal end of the cannula 22.Thanks to this configuration, it is possible to use the aforementioned “volumising” blade in the tool 10, where the precise and predetermined orientation of the cutting edges is necessary for the proper functioning of the tool 10.

[0152] In this case, the cutting edges are symmetrical with respect to a median plane orthogonal to the straight profile of the step.

[0153] Preferably, the collection chamber 25, i.e. the handle 20, and the stem 30 are mutually movable in axial sliding, alternatively between:

[0154] - a collection position of the collection chamber 25, wherein the second face 352 of the spacer 35 is in contact (with its contact portion) with the distal end of the collection chamber 25 and the collection chamber 25 is accessible (i.e., open to the outside) only through the passage opening 50 defined by the spacer 35 and by the front edge of the cannula 22, and

[0155] - a discharge position, wherein the second face 352 of the spacer 35 (and also the contact portion thereof) is distal from the distal end of the collection chamber 25 by releasing the same, i.e. opening it axially (at its free end), i.e. increasing the opening area of the collection chamber 25 with respect to the opening area thereof when the collection chamber 25 and the stem 30 are in the collection position. Preferably, the stem 30 is slidably movable within the handle 20, by means of a prismatic-type connection (i.e. without possibility of axial rotation).

[0156] As mentioned above, the collection chamber 25 has a variable volume, i.e. it has a maximum volume when the stem 30 and the collection chamber 25 are in the collection position and has a minimum volume when the stem 30 and the collection chamber 25 are in the discharge position.

[0157] In fact, when the stem 30 and the collection chamber 25 are in the collection position, the shutter disc 33 is placed at a maximum non-zero distance from the distal end of the collection chamber 25, for example greater (even twofold or threefold) than the inner diameter of the cannula 22, and when the stem 30 and the collection chamber 25 are in the discharge position, the shutter disc 33 is placed at a minimum distance (lower than the maximum distance) from the distal end of the collection chamber 25, wherein for example such minimum distance is substantially zero or in any case lower than the inner diameter of the cannula 22.

[0158] In practice, the shutter disc 33 (defining the proximal end of the collection chamber 25) issuch as to act as a plunger for discharging the bone chips collected in the collection chamber when the stem 30 and the collection chamber 25 are brought from the collection position to the discharge position, operating a back pushing action on the bone chips towards the distal end of the collection chamber 25 (released from the closure operated by the blade 40) from which they exit.

[0159] When the stem 30 and the collection chamber 25 are brought from their discharge position to the collection position, the rear tang 353 of the spacer 35 acts as a guide ramp (creeping against the distal end of the collection chamber) to take the spacer 35 to its correct position, wherein the second face 352 of the spacer 35 is in contact (with its contact portion) with the distal end of the collection chamber 25 leaving only the passage opening 50 open.

[0160] The tool 10 further comprises a locking element 60, which is configured to temporarily and / or removably mutually lock the stem 30 and the collection chamber 25 at least in their collection position.

[0161] It is not excluded that the locking element 60 may be configured to mutually lock the stem 30 and the collection chamber 25 selectively in the collection position and the discharge position.

[0162] The locking element 60 comprises, for example, a harpoon (rotatably) associated with the rear end 31 of the stem 30, which is movable between an engagement position of a seat made at (the rear end 31 of) the stem 30 and a disengagement position thereof. When the stem 30 and the collection chamber 25 are in their collection position, the seat is arranged outside (at the back of) the handle 20 and is engageable or disengageable by the locking element 60.

[0163] When the locking element 60 is in the engaged position (and the stem 30 and the collection chamber 25 are in their collection position), the locking element 60 prevents any sliding movement between the stem 30 and the collection chamber 25 (abutting against the rear end of the handle 20).

[0164] When the locking element 60 is in the engaged position, the locking element 60 allows the sliding movement between the stem 30 and the collection chamber 25, allowing them to reach their discharge position.

[0165] In light of the above, the operation of the tool 10 is as follows.

[0166] The tool 10, with the stem 30 and the collection chamber 25 in their collection position, isconfigured to be used to obtain bone particles (in the form of chips or shavings) and collect them, once separated from the bone to which they belong, within the collection chamber 25.

[0167] In order to carry out this operation, it is sufficient to hold the handgrip 21 of the tool 10 and lead the scraping edge 410 of the blade 40 into contact with a bone surface.

[0168] As the tool 10 has a curved cannula 22, as illustrated in the embodiment shown in Figures 1 - 3, the relative position between the handgrip 21 and the bone further facilitates reaching the scraping area and the scraping operations themselves.

[0169] In order to scrape a bone particle it is sufficient to scrape with the scraping edge 410 of the blade 40 in contact with the surface of a bone to be scraped, in the backward (rectilinear) direction, i.e. orthogonal to the rear face of the blade 40 in the direction from the blade 40 towards the handgrip 21.

[0170] The bone particle produced by the blade 40 is pushed (from the rear face of the blade itself) into the collection chamber 25 through the passage opening 50 defined by the spacer 35.

[0171] During such a scraping action, the stem 30 is (exclusively) tensile stressed (by the restraint reaction exerted by the bone), and extends (in contrast to the axial elasticity of the stem itself) axially (tending to detach the second face 352 of the spacer 35 from the distal end of the collection chamber 25).

[0172] When the constraint reaction of the bone is overcome by the tensile action exerted by the operator and / or the elastic reaction (exclusively axial) exerted by the stem 30, the bone particle separates from the bone, for example by a shearing action (exerted by the scraping edge 410 of the blade 40), and is forced to enter the collection chamber 25 where it is stored.

[0173] In practice, it has been observed that the axial (tensile-only) elasticity of the stem 30 is such that it produces an impulsive (pre-settable and solely dependent on the elastic modulus of the stem 30) shear force that allows (the scraping edge 410 of) the blade 40 to enhance the detachment of the bone particles from the scraped bone.

[0174] Once the desired amount of bone particles has been collected, for example by several consecutive scraping actions - as described above -, the operator may discharge the collected bone particles into the collection chamber 25, for example into a suitable collection container.To do so, it is sufficient to bring the stem 30 and the collection chamber 25 to their discharge position and to let the collected bone particles pass through the distal end of the collection chamber 25 which is disengaged from the blade 40.

[0175] The invention thus conceived is susceptible to many modifications and variants, all falling within the same inventive concept.

[0176] Moreover, all details can be replaced by other technically equivalent elements.

[0177] In practice, the materials used, as well as the contingent shapes and sizes, can be whatever according to the requirements without for this reason departing from the scope of protection of the following claims.

Claims

CLAIMS1. A cortical bone particle scraper and collector tool (10) comprising:- a handle (20) provided with a handgrip (21);- an elongated collection chamber (25) along a longitudinal axis (A);- a stem (30) at least partially arranged inside the collection chamber (25);- a blade (40) attached to a distal end (32) of the stem (30); and- a passage opening (50) defined between a rear face of the blade (40) and a distal end of the collection chamber (25) to allow the introduction of bone particles scraped by the blade (40) into the collection chamber (25),wherein a distal end (32) of the stem (30) is configured to be inserted into the distal end of the collection chamber (25), defining therewith a shape constraint so that, in use, the blade (40) only has a degree of freedom to slide axially along a direction parallel to the longitudinal axis (A) of the collection chamber (25) due to elastic elongation of the stem (30).

2. The tool (10) according to claim 1, wherein the stem (30) is obtained by injection moulding a plastic material.

3. The tool (10) according to claim 1 , comprising a spacer (35) interposed between the rear face of the blade (40) and the distal end of the collection chamber (25) to define the passage opening (50).

4. The tool (10) according to the preceding claim, wherein the spacer (35) is made in a single body with the stem (30), at its distal end (32).

5. The tool (10) according to claim 3, wherein the spacer (35) comprises at least one rear shank (353) adapted to be threaded substantially axially into the distal end of the collection chamber (25), defining the aforementioned shape constraint therewith.

6. The tool (10) according to claim 4 or 5, wherein the spacer (35) has an asymmetrical outer perimeter comprising:- a semi-circular annular body (353) configured to define a contact portion intended to contact the distal end of the collection chamber (25), and- a recess adapted to be radially separated from the distal end of the collection chamber (25) so as to define a passage channel connecting the passage opening (50) with the inside of the collection chamber (25).

7. The tool (10) according to claim 2, wherein the collection chamber (25) is curvedand the stem (30) is moulded directly into a curved shape during the injection moulding process.

8. The tool (10) according to claim 2, wherein the collection chamber (25) is rectilinear and the stem (30) is moulded directly into a rectilinear shape during the injection moulding process.

9. The tool (10) according to claim 1 , wherein the distal end (32) of the stem (30) comprises a housing seat (320), the blade (40) comprising an anchoring root (43) inserted by interference into the housing seat (320).

10. The tool (10) according to claim 1 , wherein the distal end (32) of the stem (30) and / or the blade (40) comprises an angular reference body for determining a precise and predetermined orientation of the blade (40).

11. The tool (10) according to any one of the preceding claims, wherein the blade (40) comprises a plurality of separate cutting edges.

12. The tool (10) according to claim 1, wherein the collection chamber (25) and stem (30) are mutually movable between:- a collection position, in which the spacer (35) is in contact with the distal end of the collection chamber (25) and the collection chamber (25) is only accessible from the outside via the passage opening (50) defined by the spacer (35), and- a discharge position, in which the spacer (35) is separated from the distal end of the collection chamber (25).

13. The tool (10) according to the preceding claim, further comprising a locking element (60) configured to temporarily lock the stem (30) and the collection chamber (25) at least in the collection position.

14. A method of manufacturing a cortical bone particle scraper and collector tool (10) according to any one of the preceding claims, comprising the steps of:- injection moulding a plastic material to form a stem (30) with a distal end (32) configured to adapt to the collection chamber (25);- inserting a blade (40) by interference coupling into a housing (320) at the distal end (32) of the stem (30);- assembling the stem (30) inside the collection chamber (25) so that a passage opening (50) for the bone particles remains defined between the blade (40) and a distal end of the collection chamber (25).

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