Patent Description:
As it is known, in the case of bone fractures, but also in corrective osteotomies and arthrodesis, making a surgical treatment of osteosynthesis, in which by means of a mechanical system of internal fixation are stabilized (immobilized) two or more bones heads (fragments) in order to allow bone healing.

The mechanical system to be used, besides being biocompatible, must be stable over time and must be suitably robust. In particular, this system must be suitably sized for the type and extent of the bone union to be made; in fact, if the implant is too light, it risks bending and deforming, while if it is too heavy, the bone is reabsorbed.

Moreover, the mechanical implant must be fixed to the bone in a stable manner, however this implant must not be too rigid as, to obtain an appropriate healing, it is necessary that the bone is appropriately stressed. In particular, the implant must be sized and implanted so that the stress of the physiological load partly reaches the area of bone discontinuity and this in order to stimulate the activity of the osteoblasts and therefore the development and consolidation of the bone.

The internal fixation mechanical implant generally comprises a plate which is fixed by screws to the respective bone ends to be immobilized. In particular, the plate consists of a plate that is fixed by screws to the bone fragments to be joined in order to stabilize them and stimulate them, thus allowing bone healing.

Among the known internal fixation implants to stabilize corner there is the so-called internal fixator "Fixin", which comprises three components: the plate member, the compass and the screw. More in detail, the compass has a threaded external side wall, to allow screwing within the threaded through holes of the plate, and a conical internal hole which cooperates with the corresponding conical head of the screw; moreover, the compass has a grooved collar which engages with the end of a corresponding instrument configured to screw/unscrew the compass into the hole of the plate.

In the internal fixer "Fixin" the plate is particularly weakened from the need to obtain inside it a threaded hole of increased diameter to allow the insertion of the compass. In particular, this makes the plate less resistant to both static stresses (for example, when it bends as the patient rises) and to dynamic stresses (for example, it breaks with fatigue, after about a month, when the patient walks).

Furthermore, in general, the removal of the present internal fixation mechanical systems is rather problematic.

Indeed, once any plate of a known system is implanted, it may happen that there is a need to remove it, for example, because the same plate is infected, bent or broken, or because some screws are broken or unscrew, or because it might cause the occurrence of tumoral forms, or because the bone is reabsorbed, etc.. Currently, for the removal of the plate of the known internal fixation implants it is necessary to make a rather large cut on the skin and on the underlying tissues so as to be able to first access the individual screws, to remove them from the bone, so as to then proceed to the plate extraction through the cut made. In essence, this surgical operation for plate removal is particularly invasive, complicated and laborious, as well as having high morbidity and high risk of infections, as well as leaving extensive and apparent skin scars.

Another known internal fixation mechanical implant is described in the <CIT>. In particular, this system provides for the use of a plate in which a plurality of through holes are made to be traversed by corresponding fixing screws which have, in sequence, a head, a flared portion (collar) and a self-tapping stem. More in detail, unlike the "Fixin" system, the system described in PN2013U000037 does not provide for the use of compasses since the holes in the plate themselves define a conical/flared housing for the corresponding conical/flared portion of the fixing screws. In essence, the stabilization of the implant is obtained by direct conical coupling between the plate and the screws.

Furthermore, the head of the fixing screws has the top a cavity delimited by a threaded inner wall which thus defines a threaded coupling for locking a first instrument, which acts as a screwdriver. In particular, by screwing the end of the screwdriver on the threaded coupling of the head, the screwdriver is made integral in rotation with the screw so that - following the further rotation of the screwdriver - the threaded portion of the screw is inserted into a corresponding bone fragment.

Appropriately, the screwing - caused by the action exerted on the screwdriver - of the screw within the bone limb continues until the flared portion of the screw itself engages within the corresponding flared seat of the through hole of the plate.

Furthermore, the head of the screw - which is substantially cylindrical or mushroom-shaped - has on its external wall, a thread for the engagement/fixing of a second and different instrument, which acts as an extractor. In particular, by screwing the end of the extractor onto the external wall of the screw head, the extractor is made integral with the screw so that - following the further rotation of the extractor - the threaded portion of the screw disengages from the corresponding flap bone.

In essence, the solution described in PN2013U000037 concerns a kit which, in addition to the internal fixation mechanical implant, also includes a first tool for screwing the screw into the bone fragment and a second instrument (which is completely distinct and independent of said first instrument) to unscrew the screw so to extract it from the fragment bone.

These known kits - which includes the plate, the screws, the screwdriver and the extractor - is particularly satisfactory, however its current mode of realization it is rather complicated and, moreover, the operations carried out to achieve the conical coupling between the holes of the plate and the collar of the screws do not allow to obtain high precision levels. In particular, the conical through holes made inside the plate do not reach the particularly narrow tolerances required by the context of application, tolerances which are generally of the order of one hundredth of a millimetre.

<CIT> describes a device for stabilizing the vertebrae in the human spine. In particular, this device comprises a series of screws which engage in corresponding holes formed in a plate so as to keep the latter in contact with the vertebrae. More in detail, the screws have a threaded stem and a head which is entirely conical/flared and which is configured to substantially pass through the corresponding hole in the plate. In this solution, the screws are extremely difficult and complicated to remove.

<CIT> describes a solution for bone fixation in which a screw to be inserted directly, without any plaque, into the desired bone area. In particular, this screw is externally threaded and has a hollow longitudinal passage inside it; furthermore, the screw head is externally threaded to allow its engagement by an insertion tool to be used to guide said screw into the desired bone area.

<CIT> describes a cervical plate formed by an elongated asymmetrical body having one or more through openings which cross the plate from one face to the other; moreover, bone fixing screws are provided comprising a threaded stem and a head configured to be entirely housed within a corresponding through opening formed in the plate.

<CIT> discloses a bone plate and a fixation system with two types of bone screws, i.e. one type having a partially spherical head and one type having a thread or conical head.

Purpose of the invention is to provide an improved kit for orthopedics, preferably for osteosynthesis, which overcomes the drawbacks of the traditional solutions and is an improvement and/or an alternative compared to said solutions.

Another object of the invention is to provide a kit in which the components can be made and machined with high precision, thus allowing a coupling between said components which is as stable as possible and free from play.

Another object of the invention is to provide a kit that is simple, quick and intuitive to use.

Another object of the invention is to provide a kit with an alternative characterization, both in constructive and functional terms, with respect to the traditional ones.

Another object of the invention is to provide a kit that can be obtained simply, quickly and at low cost.

Another object of the invention is to provide a kit that can be used on several pathologies and validated in the field of orthopedics.

Another object of the invention is to provide a high quality, robust, reliable, non-invasive and safe kit both for the operator and the patient.

Another object of the invention is to provide a kit that allows an easy and rapid removal of the mechanical fixing system.

All these aims, both individually and in any combination thereof, and others which will emerge from the following description, are achieved, according to the invention, with an improved kit for orthopedics, preferably for osteosynthesis, having the characteristics indicated in the claim <NUM>.

In particular, the present invention relates to an improved kit (<NUM>) for orthopedics, preferably for osteosynthesis, comprising a internal mechanical fixing system (<NUM>) which comprises a plate (<NUM>) to be mounted straddling two bone fragments to be joined (<NUM>', <NUM>") and at least two, preferably at least four, fixing screws (<NUM>) to fix the plate to said two bone fragments (<NUM>', <NUM>"), wherein:.

Advantageously, said kit also comprises a screwing tool (<NUM>) which is provided with:.

Advantageously, said kit also comprises a gripping tool (<NUM>) which is provided with a stem (<NUM>) which has a tubular end portion (<NUM>) which is internally hollow and is internally provided with a female thread (<NUM>) adapted to be screwed to the thread (<NUM>) provided on the external side wall (<NUM>) of the head (<NUM>) of the fixing screw (<NUM>).

Advantageously, said kit also comprises an adapter (<NUM>) for transforming the screwing tool (<NUM>) into a gripping tool (<NUM>), said adapter (<NUM>) comprising a tubular stem (<NUM>), internally hollow, inside which it is destined to be inserted the stem (<NUM>) of the screwing tool (<NUM>), said tubular stem (<NUM>) having a tubular end portion (<NUM>) which is internally hollow and is internally provided with a female thread (<NUM>) configured to be screwed to the thread (<NUM>) provided on the external side wall (<NUM>) of the head (<NUM>) of the fixing screw (<NUM>).

Advantageously, said kit also comprises a tensioning device (<NUM>) which comprises two members (<NUM>, <NUM>), to be associated with two distinct bone fragments (<NUM>', <NUM>"), and connected to each other so as to allow their mutual approach/removal, at least one of said two members (<NUM>, <NUM>) is configured to be associated with said plate (<NUM>) by means of said gripping tool (<NUM>) which passes through and/or is associated with said member (<NUM>, <NUM>) and which is screwed with its tubular end portion (<NUM>) onto the thread (<NUM>) of the head (<NUM>) of a screw (<NUM>) which, passing through a conical through hole (<NUM>) provided in said plate, fixes it to a corresponding fragment bone (<NUM>', <NUM>").

Advantageously, said kit also comprises a tip centering device (<NUM>) which is configured to guide a drilling tip (<NUM>) so as to create in the bone (<NUM>', <NUM>") a longitudinal cavity (<NUM>), inside which is intended to be inserted and housed the fixing screw (<NUM>), which is aligned with the axis that passes through the conical through hole (<NUM>) of the plate (<NUM>), said tip centering device (<NUM>) comprising a tubular element (<NUM>) with an internal channel (<NUM>) which is adapted to be crossed and to guide said drilling tip (<NUM>), said tubular element (<NUM>) presenting:.

In particular, the present invention relates to a screwing tool (<NUM>) which is provided with:.

In particular, the present invention relates to a gripping tool (<NUM>) which is provided with a stem (<NUM>) which has an tubular end portion (<NUM>) which is internally hollow and is internally provided with a female thread (<NUM>) suitable for being screwed to the thread (<NUM>) provided on the external side wall (<NUM>) of the head (<NUM>) of the fixing screw (<NUM>).

In particular, the present invention relates to an adapter (<NUM>) for transforming the screwing tool (<NUM>) into a gripping tool (<NUM>), said adapter (<NUM>) including a tubular stem (<NUM>), internally hollow, inside which the stem (<NUM>) of the screwing tool (<NUM>) is intended to be inserted, said tubular stem (<NUM>) having a tubular end portion (<NUM>) which is internally hollow and is internally provided with a female thread (<NUM>) suitable for being screwed to the thread (<NUM>) provided on the external side wall (<NUM>) of the head (<NUM>) of the fixing screw (<NUM>).

Moreover, the present invention relates to a tensioning device (<NUM>) which comprises two members (<NUM>, <NUM>), to be associated with two distinct bone fragments (<NUM>', <NUM>"), and connected with each other so as to allow their mutual approach/removal, at least one of said two members (<NUM>, <NUM>) is configured to be associated with said plate (<NUM>) by means of said gripping tool (<NUM>) which passes through and/or is associated with said member (<NUM>, <NUM>) engaging by screwing its tubular end portion (<NUM>) onto the thread (<NUM>) of the head (<NUM>) of a screw (<NUM>) which, passing through a conical through hole (<NUM>) provided in said plate, fix the latter to a corresponding bone fragment (<NUM>', <NUM>").

In particular, the present invention relates to a tip centering device (<NUM>) which is configured to guide a drilling tip (<NUM>) so as to create in the bone (<NUM>', <NUM>") a longitudinal cavity (<NUM>), inside of which the fixing screw (<NUM>) is intended to be inserted, tip centering device (<NUM>) which is configured to guide a drilling tip (<NUM>) so as to create a longitudinal cavity (<NUM>) in the bone (<NUM>', <NUM>"), inside which the fixing screw (<NUM>), which is aligned with the axis that passes through the conical through hole (<NUM>) of the plate (<NUM>) is intended to be inserted and housed, said tip centering device (<NUM>) comprising a tubular element (<NUM>) with an internal channel (<NUM>) which is suitable to be crossed and for guiding said drilling tip (<NUM>), said tubular element (<NUM>) presenting:.

The present invention is further clarified hereinafter in a preferred embodiment thereof, given purely by way of a non-limiting example, with reference to the accompanying drawings, in which:.

As can be seen from the figures, the improved kit for orthopedics, preferably for osteosynthesis, generally indicated with the reference number "<NUM>" includes an internal mechanical fixing system <NUM> and at least one tool <NUM>, <NUM> and <NUM> for its application, its handling/movimentation together with the bone and/or its removal.

The internal mechanical fixing system <NUM> includes a plate <NUM>, to be positioned at the bone fragments <NUM>' and <NUM>" to be joined, and at least two fixing screws <NUM> (that is at least one screw for each bone fragment) to fix the plate to the corresponding bone fragments. Preferably, the internal mechanical fixing system <NUM> comprises at least two - preferably four - fixing screws <NUM> for each bone fragment. Preferably, all the fixing screws <NUM> of the internal mechanical fixing system <NUM> are equal to each other.

Conveniently, the plate <NUM> is made of biocompatible metal material, preferably in stainless steel, in particular in AISI 316LVM, or titanium alloy Ti6AI4V.

Conveniently, the fixing screws <NUM> are made of biocompatible metallic material, preferably of stainless steel, in particular of AISI 316LVM, or titanium alloy Ti6AI4V. The plate <NUM> comprises a plate of reduced thickness and, in particular, having a thickness of about <NUM> - <NUM>. Preferably, the plate <NUM> has a thickness of:.

Preferably, the plate <NUM> and the fixing screws <NUM> are made of biocompatible metal materials different from each other, for example the plate is made of steel while the screws are made of titanium alloy, or vice versa. Advantageously, in the case of a plate with a thickness of less than <NUM> -<NUM>, the plate and the screws are made of the same metallic material (for example in steel or in titanium alloy), while in the case of a plate with a thickness greater than <NUM> the plate and the fixing screws are made of different metallic materials.

Advantageously, the reduced thickness of the plate <NUM> allows its application at and in close proximity to the bone fragments to be joined <NUM>' and <NUM>" and, moreover, allows a suitable longitudinal flexibility of the same so as to stress the fragments to which it is applied; moreover, the reduced thickness of the plate <NUM> allows it to be positioned/implanted below the skin.

The plate <NUM> has at least two - preferably at least four - through holes <NUM> which pass through the plate from side to side (i.e. cross the thickness of the plate) and have a conical (i.e. substantially flared) shape. Conveniently, the conical through holes <NUM> define the seats for the insertion of the fixing screws <NUM>, thus allowing the coupling of these with the plate <NUM>.

Preferably, each conical through hole <NUM> of plate <NUM> it has an entirely conical shape, i.e. it is conical for its entire length along the thickness of the plate <NUM>.

Preferably, each conical through hole <NUM> of the plate <NUM> has a diameter (defined at the minor section of the conical section) of about <NUM> - <NUM>. In particular, advantageously, the fact that the conical through holes <NUM> formed in the plate <NUM> have particularly small diameters (i.e., about <NUM> - <NUM>) - and in any case lower than those envisaged, with the same screw diameter being equal fixing, in traditional "Fixin" systems - makes the plate <NUM> more robust to both static and dynamic stresses.

Conveniently, the inner wall <NUM> which delimits the conical through hole <NUM> is not threaded.

Appropriately, considering as "internal surface" of the plate the one which - once the plate itself is implanted - is facing closer to the <NUM>', <NUM>" bone fragments and as the "external surface" the other surface (i.e. the opposite surface), it follows that - going from the outer surface toward the inner surface of the plate - the inner wall <NUM> which delimits each conical through hole <NUM> is slightly inclined/flared from the outside towards the intern.

Conveniently, the inner wall <NUM> which delimits each conical through hole <NUM> of the plate <NUM> is tilted/flared towards the interior of such an angle as to allow a suitable coupling with a corresponding conical portion <NUM> (i.e., the collar is interposed or between the head <NUM> and the stem <NUM>) of the fixing screw <NUM>, but at the same time it must not cause the joint of the latter since otherwise it would not be possible to remove the screw from the plate.

Advantageously, the inner wall <NUM> of each conical through hole <NUM> of the plate <NUM> is inclined of about <NUM>° - <NUM>° with respect to the axis passing through the through hole, preferably it is inclined of about <NUM>°.

Advantageously, the engagement of the conical portion <NUM> within the conical through hole <NUM> is of the self-centring type, thus automatically allowing the locking and the centring of the screw <NUM> within a corresponding hole <NUM> of the plate <NUM>.

Conveniently, the development axis of the conical through hole <NUM> is coincident with or parallel to the axis perpendicular to the outer surface of the plate <NUM>. However, suitably, the development axis of the conical through hole <NUM> can also be inclined with respect to the axis perpendicular to the external surface of the plate <NUM>. In other words, the conical through hole <NUM> can have a development axis which is inclined from the outside surface to the internal surface of the plate <NUM>.

Advantageously, the conical through hole <NUM> of the plate <NUM> it is not obtained exclusively by burr removal through the use of a reamer, but a surface finishing treatment is also provided by rolling so as to reach the required tolerance (i.e. of the order of one hundredth of a millimetre).

Preferably, each conical through hole <NUM> of the plate <NUM> is obtained in the following passages, in each of which a different tool is used.

In the first step (see <FIG>) a marking operation <NUM> is performed on the upper surface of the plate <NUM>, and in particular a machining operation is carried out in order to obtain a starting hole <NUM> to then facilitate the insertion of the tool tip to be used in the next step. Advantageously, this marking operation <NUM> is carried out using a tool with a center point <NUM>.

In the second step (see <FIG>), a cutting operation (drilling) <NUM> is carried out in order to obtain a cylindrical hole <NUM> which runs entirely through the thickness of the plate <NUM>. Advantageously, this operation <NUM> is carried out by means of a tool with a helical tip <NUM>, preferably with at least three cutting edges.

In the third step (cfr. <FIG>) performing a boring and/or reaming operation <NUM> intended to give a conical shape <NUM> to the previously obtained cylindrical hole <NUM>. Advantageously, this operation is carried out by means of a reamer tool <NUM> with a conical tip. Conveniently, by means of this operation a pre-calibration of the conical hole to be obtained on the plate <NUM>.

Conveniently, a fourth passage is finally provided (see <FIG>) in which a surface finish by rolling <NUM> is carried out on the conical-shaped hole <NUM> so as to achieve the required tolerance and, in particular, a tolerance of the order of the hundredth of millimetre. Advantageously, through the surface finishing by rolling <NUM> the inner wall of the conical-shaped hole <NUM> is plastically and gradually deformed so as to smooth it superficially, and thus obtain the conical through hole <NUM>. Conveniently, by this operation the final calibration of the conical-shaped hole <NUM> is substantially carried out so as to bring it to the required precision or finish.

Conveniently, a conical tip <NUM> is used which is laterally shaped and, preferably, is of the step type.

Suitably, the finishing by rolling <NUM> - which is a process that does not require any burrs removal - allows a low wear of the tool used for the corresponding processing and, moreover, allows a plurality of high precision conical through holes <NUM> to be made quickly in the plate.

Advantageously, the plate <NUM> has lateral swellings <NUM> at the area in which the conical through holes <NUM> are formed. Advantageously, the conical through holes <NUM> can be distributed symmetrically with respect to the central area of the plate <NUM> or they can also be distributed asymmetrically with respect to the transverse and/or longitudinal development of the plate itself.

Preferably, the plate <NUM> has a substantially elongated development (i.e. it is narrow and long). Appropriately, the plate <NUM> can comprise several portions - each provided with at least one conical through hole <NUM> - which are aligned with each other or angled.

The fixing screws <NUM> comprise, in sequence, a head <NUM>, a collar <NUM> and a conic or self-tapping stem <NUM> intended to be screwed into a corresponding longitudinal cavity <NUM> formed in the bone fragment <NUM>' or <NUM>". In particular, the conical collar <NUM> acts as a connection between the head <NUM> and the self-tapping stem <NUM>.

Conveniently, the self-tapping stem <NUM> is configured to thread the cylindrical hole of the longitudinal cavity <NUM> formed in the bone fragment <NUM>' or <NUM>" during its screwing into said cavity. Preferably, the end of the self-tapping stem <NUM> can be pointy. Preferably, the body of the self-tapping stem <NUM> can be cylindrical or conical. Conveniently, the self-tapping stem <NUM> could also be self-drilling, i.e. capable of creating the longitudinal cavity <NUM> itself.

Conveniently, it is understood that the diameter of the cross-section of the longitudinal cavity <NUM> which is formed in the bone fragment <NUM>' or <NUM>" is slightly smaller than the external diameter of the self-tapping stem <NUM> of the screw <NUM> to be inserted in said cavity. For example, for a screw <NUM> with an external diameter of the self-tapping stem <NUM> of about <NUM>, the diameter of the cross-section of the longitudinal cavity <NUM> obtained on the bone fragment will be about <NUM>.

Advantageously, the self-tapping stem <NUM> has a groove at the tip to perform a tapping action on the longitudinal bone cavity <NUM> for preparation.

Conveniently, the head <NUM> has an external side wall <NUM> of a certain height (preferably of about <NUM>-<NUM>) and, preferably, is substantially cylindrical or mushroom-shaped.

The head <NUM> has on its surface greater than a recessed and shaped mark <NUM> (recess) for engagement - by the, at least partial, shape coupling - of the tip <NUM> of one or screwing/unscrewing tool <NUM> (hereinafter referred to as "threading tool "For simplicity).

Preferably, the tip <NUM> of the screwing tool <NUM> has a solid portion which is shaped correspondingly, i.e. substantially complementary, to the shape of the recessed mark <NUM>. In essence, the shaped tip <NUM> of the screwing tool <NUM> defines a male element that is inserted within a female element which is defined by the shaped recessed mark <NUM> that is formed on the upper surface of the head <NUM> of the fixing screw <NUM>.

Advantageously, the fact that the head <NUM> presents a recessed mark (recess) <NUM> and shaped for engagement by coupling, at least partial, of the shape of the tip <NUM> of the screwing/unscrewing tool <NUM> ensures the buoyancy perpendicularity between the screw head and the threading tool, thus allowing to reduce and avoid the risk of stripping said mark <NUM>.

Advantageously, the recessed mark <NUM> can be shaped like a cross, square, hexagonal (Allen), cross-shaped with misalignement or star- shaped axes.

Preferably, the recessed mark <NUM> is of the type known under the trade name "Torx", hereinafter "Torx imprint", which is standardized in the ISO10664 standard with the name "hexalobular internal seat for screws" and substantially presents a star-shaped with six points. In particular, the Torx footprint is particularly advantageous as it allows:.

In particular, the fact that the recessed and shaped mark <NUM> is not internally threaded (such as for example in the solution presented in PN2013U000037) avoids problems of stripping as a result of the engagement of the tip of the screwdriver within said coupling.

Advantageously, the recessed and shaped mark <NUM> of the head <NUM> has a hollow central portion <NUM>, preferably substantially cylindrical, which is surrounded by lateral discharge grooves <NUM> which are not provided in the corresponding full shape defined by the tip <NUM> of the screwing tool <NUM>. Appropriately, a part of the solid fibrous material that has settled inside the recessed and shaped mark <NUM>, is pressed on the bottom of the latter by the tip <NUM> of the screwing tool <NUM> while the discharge grooves <NUM> define recesses in which - by means of the tip <NUM> of the screwing tool <NUM> - the liquid or fluid fibrous material is pushed, which deposits inside the recessed and shaped mark <NUM>, so as to cause it to escape from the same mark through said grooves <NUM>. Substantially, in this way, the head <NUM> of the screw <NUM> is cleaned from the fibrous material or bone that has settled following the application of the screw itself in the bone; in particular, this cleaning is carried out during the first implantation phase of the screw on the bone but, most important, on the occasion of its eventual removal from the bone itself.

Advantageously, the discharge grooves <NUM> can be formed at the points of the star-shaped shape of the recessed mark <NUM> shaped like a torx.

Suitably, as mentioned, the head <NUM> of each screw <NUM> presents along/on its external side wall <NUM> a thread <NUM> for engagement/fastening of a gripping (extracting/manipulating) tool <NUM>. In particular, by screwing the ends of or gripping tool <NUM> on the threaded external side wall <NUM> of the head <NUM> of the screw <NUM>, it makes the tool integral with said screw <NUM>; conveniently, in this way, by moving the gripping tool <NUM>, the operator can pull, move and displace the bone fragment <NUM>' or <NUM>" in which the stem <NUM> of the screw <NUM> is inserted, whose head <NUM> has been made integral with said tool <NUM>.

Conveniently, the thread <NUM> of the threaded external side wall <NUM> of the head <NUM> of the screw <NUM> is helical, and it develops in the opposite direction with respect to that of the rotation to be imparted to the screw itself in order to screw the self-tapping stem <NUM> into the bone fragment <NUM>' or <NUM>". Conveniently, the thread <NUM> of the external side wall <NUM> of the head <NUM> of the fixing screw <NUM> is a left helix.

Suitably, the gripping tool <NUM> is configured to be screwed to the thread <NUM> of the threaded external side wall <NUM> of the head <NUM> of the screw <NUM> until the tubular end portion <NUM> of said instrument enters into abutment with the outer surface of the plate <NUM> - around the screw itself.

Advantageously, the engagement by screwing between the gripping tool <NUM> and the head <NUM> of the fixing screw <NUM> allows a more stable constraint between them, thus allowing to be able to exert a greater force on the instrument both for extraction and for manipulation.

Conveniently, moreover, the fact that the head <NUM> of the screw <NUM> on its external side wall <NUM> has a thread <NUM> which allows the suture thread to be anchored around the latter to draw near the tissues or to close the skin.

The collar <NUM> of the fixing screw <NUM> has a conical shape which is configured - both in terms of shape and size - to be inserted and coupled stably but removably within a corresponding conical through hole <NUM> formed in the plate <NUM>.

In essence, the coupling between the collar <NUM> of the fixing screw <NUM> and the conical through hole <NUM> of the plate <NUM> is of the conical type. Suitably, the conical coupling between the collar <NUM> of the screw <NUM> and the conical through hole <NUM> ensures the stable locking of the internal mechanical fixing system <NUM> (which includes the plate <NUM> and the screws <NUM>) of the fragments bone <NUM>' and <NUM>", thus guaranteeing the stable fixation of the latter.

In particular, the fixing screw <NUM> is configured so that, when the collar <NUM> of said screw is engaged/locked in the conical through hole <NUM> of the plate <NUM>, the head <NUM> protrudes/leak externally at least in part - preferably entirely - with respect to the plate itself, and in particular protrudes from the outer surface of said plate (see <FIG> and <FIG>). Preferably, the head <NUM> of each fixing screw <NUM> has a flange <NUM> for the connection with the collar <NUM> and, appropriately, said flange <NUM> is designed to protrude and be slightly spaced (for example of about <NUM>) with respect to the to the outer surface of the plate <NUM> when the conical collar <NUM> of the fixing screw <NUM> is inserted or within the conical through-hole <NUM> of the plate itself. Preferably, the flange <NUM> has a substantially flat development (horizontal or slightly inclined) and is destined to be slightly spaced from the more external surface, substantially flat, provided in the plate <NUM> around the conical through hole <NUM>.

The fact that the head <NUM> of the fixing screw protrudes beyond the plate <NUM> is particularly advantageous in that it allows the engagement of the tubular end portion <NUM> of the gripping tool <NUM> (as described more extensively below) and, in particular, this is useful during the step of extraction of the screw which, in fact, can take place both by means of the gripping tool <NUM> and - as a last attempt - also by means of handles or pincers which engage/grip with the respective jaws the head <NUM> which protrudes from the plate <NUM>.

Conveniently, in the kit <NUM> and, in particular, in the system <NUM>, no compassing or other supporting elements are provided for the engagement of the screw <NUM> with the plate <NUM>. In other words, advantageously, the fixing system <NUM> it consists only of plate <NUM> and fixing screws <NUM>.

The screwing tool <NUM> (see. <FIG>) comprises an ergonomic handle <NUM>, intended to be gripped by the operator, and a stem <NUM> that is fixed to the handle and that - as said - in correspondence of its free tip <NUM> presents a solid portion which, preferably, is shaped in a corresponding manner, i.e. substantially complementary with respect to the shape of the recessed mark <NUM> on the upper surface of the head <NUM> of the fixing screw <NUM> (see <FIG>). Appropriately, the screwing tool <NUM> can be a traditional screwdriver whose tip has - preferably - a solid portion which is shaped in a corresponding manner, that is substantially complementary with respect to the recessed mark <NUM> on the upper surface of the head <NUM> of the fixing screw <NUM>.

Advantageously, the engagement/interlocking of the free tip <NUM> of the screwing tool <NUM> within the recessed mark <NUM> provided in the head <NUM> of the fixing screw <NUM> causes - once the screw has been taken and the aforementioned engagement/engagement is performed - the screw itself can reach the operating table, without falling, during the operations that precede its insertion into the conical through hole <NUM> of the plate <NUM> and its screwing into a corresponding longitudinal cavity <NUM> formed in the bone fragment <NUM>' or <NUM>".

Advantageously, the kit <NUM> according to the invention also comprises a tip centering device to <NUM> (see <FIG>). In particular, the tip centering device to <NUM> is a device configured to drive a drilling tip <NUM> of a drill or of another punching tool (not shown) so as to create in the bone <NUM>' or <NUM>" a longitudinal cavity <NUM> (inside of which the fixing screw <NUM>) is intended to be inserted and housed, which is aligned (in axis) with the conical through hole <NUM> of the plate <NUM>. Suitably, to this end, the tip centering device to <NUM> is substantially a tubular element <NUM> with an internal channel <NUM> that is suitable to be crossed and to guide the drilling tip <NUM> of the drill or other puncher tool.

Moreover, the tubular element has an end portion <NUM> which is conical and is shaped to be complementary to and engage within a corresponding conical through hole <NUM> of the plate <NUM> in such a way that said internal channel <NUM> is aligned with the axis that passes through said conical through hole <NUM>. Suitably, going from the tubular body of the element <NUM> towards the conical end portion <NUM>, a tapered connecting portion <NUM> can be provided.

Advantageously, at the other end portion (i.e. the opposite portion with respect to the conical end portion <NUM>) of the tubular element <NUM>, the internal longitudinal channel <NUM> has an inlet portion <NUM> which has a larger cross section (i.e. wider) than the remaining part (more internal) of channel <NUM>. Preferably, the section of the inlet <NUM> is shaped like a funnel. Suitably, the fact that the tip centering device <NUM> presents such a widened inlet portion <NUM> allows to spray more (and thus cool) the tip <NUM> of the drill, piercer or tool, which overheats as a result of and during the cutting operation used to make the longitudinal cavity <NUM> in the bone <NUM>' or <NUM>".

So, to fix the plate <NUM> to a fragment bone <NUM>' or <NUM>" by means of one or more fixing screws <NUM> the following operations are performed:.

Preferably, more in detail, to screw the self-tapping stem <NUM> of each fixing screw <NUM> into the bone fragments <NUM>' and <NUM>", the screwing tool <NUM> - once its tip <NUM> has engaged in the recessed and shaped mark <NUM> obtained on the head <NUM> of the screw <NUM> - is rotated in a clockwise direction. Conveniently, the rotation action performed by means of the screwing tool <NUM> continues until the conical collar <NUM> of the fixing screw <NUM> fits into abutment and is coupled within the corresponding conical through hole <NUM> formed in the plate <NUM>.

The gripping tool <NUM> comprises an ergonomic handle, intended to be gripped by the operator, with its own stem <NUM> which, at its free tip, has an tubular end portion <NUM> which is internally hollow and internally is provided with a nut screw <NUM> designed to be screwed to the thread <NUM> formed on the external side wall <NUM> of the head <NUM> of the fixing screw <NUM>. Preferably, the female thread <NUM> of the tubular portion <NUM> of the gripping tool <NUM> is left-handed and, therefore, in order to screw the latter to the head <NUM> of the fixing screw <NUM> it is necessary to rotate the gripping tool in an anti-clockwise direction.

Conveniently, the rotation action carried out by the gripping tool <NUM> continues until the tubular end portion <NUM> of the latter abuts with the plate <NUM>, thus making the gripping tool integral in rotation with the fixing screw <NUM>. Therefore, the further rotation effected by the gripping tool <NUM> first causes the decoupling/disengagement (due to the axial component of the helical movement) of the conical collar <NUM> of the fixing screw <NUM> from the corresponding conical through hole <NUM> of the plate <NUM> and then causes the fixing screw <NUM> to be unscrewed from the corresponding bone fragment <NUM>' or <NUM>"; suitably, the screw <NUM> is extracted from the bone fragment <NUM>' and/or <NUM>" by unscrewing it with the same pitch used for its insertion and this avoids damaging the threads of the nut screw of the longitudinal cavity <NUM> (which defines the bony hole) and to cause the latter to be enlarged.

Advantageously, in an embodiment not represented, the screwing tool <NUM> can be a completely different and separate instrument from the gripping tool <NUM>, that is, two instruments are provided each with its handle.

Advantageously, in the embodiment represented here (see <FIG>), the gripping tool <NUM> comprises an adapter <NUM> for transforming the screwing tool <NUM> into said gripping tool <NUM>. In particular, this adapter <NUM> comprises a tubular stem <NUM>, internally hollow, inside which the stem <NUM> of the screwing tool <NUM> is inserted to allow the pointing and the quick/easy engagement of the gripping tool <NUM> on the head <NUM> of the screw <NUM>. Advantageously, in this way, as will become clearer below, the screwing tool <NUM> substantially acts as a pointer/stabilizer and as an internal guide element for the adapter <NUM> which acts as a gripping tool <NUM>.

Suitably, the tubular stem <NUM> adapter <NUM> terminates with the tubular end portion <NUM> which is internally hollow and is provided internally with the female thread <NUM>, as described above. Conveniently, the tubular stem <NUM> can be associated with a connecting portion <NUM> which extends the handle <NUM> of the screwing tool <NUM>. Conveniently, it is understood that the adapter <NUM> is configured - and in particular its tubular stem <NUM> is dimensioned - so that, once it has been inserted into the screwing tool <NUM>, the shaped solid tip <NUM> of the latter fits into the contoured and recessed mark <NUM> of the head <NUM> of the screw <NUM>, thus facilitating positioning and the coupling on the latter also of the tubular end portion <NUM> of the tubular stem <NUM> of the adapter <NUM>. Advantageously, using the adapter <NUM> and thus inserting the full shaped tip <NUM> of the screwing tool <NUM> into first the tubular stem <NUM> of said adapter and then entering the contoured and recessed mark <NUM> of the head <NUM> of the screw <NUM> facilitates the screwing of the female thread <NUM> of the tubular stem <NUM> of the adapter <NUM> to the thread <NUM> of the external side wall <NUM> of the head <NUM> of the screw <NUM>.

Generally, to carry out the removal of the internal mechanical fixing system <NUM>, only the screwing tool <NUM> is used.

In particular, to carry out the removal of the internal mechanical fixing system <NUM>, the operator generally palpates the skin - in correspondence with the body area where the internal mechanical fixing system <NUM> was positioned - to identify the protrusion of the head of the fixing screws <NUM>. Then, once this protrusion has been identified, the operator makes a skin and subcutaneous incision over the recessed mark <NUM> of the head <NUM> of the screw <NUM> and this in order to allow the insertion of the tip <NUM> of the screwing tool <NUM> and the engagement of said tip in the mark <NUM>.

Conveniently, it is intended that in order to carry out the removal of a internal mechanical fixing system <NUM> which is positioned well below the skin (for example, in the case of the femur, the humerus and the pelvis the internal mechanical fixing system <NUM> is at a depth of approximately <NUM>-<NUM> below the skin), the operator first carries out skin incision in a body area suitable for the access and then moves the various tissues (muscles, tendons, vessels and nerves) in order to create a corresponding passage; then, palpates the head <NUM> of the screws <NUM> and insert the tip <NUM> of the screwing tool <NUM> through the skin incision and the passage thus defined until it engages it within the recessed and shaped mark <NUM> of said head <NUM>.

Therefore, in both cases, once the tip <NUM> of the screwing tool <NUM> has engaged in the recessed and shaped mark <NUM> formed on the head <NUM> of the screw <NUM>, said instrument is rotated counter clockwise (or in any case in the opposite direction compared to that used to insert the screw into the bone fragment) in order to extract/decouple the screw either from the longitudinal cavity <NUM> obtained in the bone fragment <NUM>' or <NUM>" and from the conical through hole <NUM> made in the plate <NUM>.

The exit from the skin of the head <NUM> of the screw <NUM>, and the remaining part of the screw <NUM> (that is, of the collar <NUM> and of the self-tapping stem <NUM>), is favored by the thread <NUM> of the external side wall <NUM> which allows the screw itself to pass through the tissues without lifting them. Suitably, in other words, the thread <NUM> of the external side wall <NUM> of the head <NUM> of the screw <NUM> allows to extract the screw itself by making a particularly reduced and minimally invasive incision on the skin.

In some cases - for example when the screw <NUM> is deeply inserted in the bone fragment <NUM>' and/or <NUM>" and/or when the conical coupling between the collar <NUM> of the screw and the conical through hole <NUM> of the plate defines a joint difficult to remove and/or when the recessed mark <NUM> is stripped, - to carry out the mechanical removal of the internal mechanical fixing system <NUM> is used, in addition or as an alternative to the screwing tool <NUM>, the gripping tool <NUM>, which obviously requires of make a cutaneous cut slightly larger than the one necessary in the case of using only the screwing tool <NUM>. Therefore, also in this case, once the protruding raised portion of the head <NUM> of the fixing screws <NUM> has been identified, the operator carries out a skin incision, or enlarges the previously performed one, so as to allow the insertion of the gripping tool <NUM> which is screwed with its tubular end portion <NUM> on the external side wall <NUM> of the head <NUM> of the fixing screw <NUM> so that the female thread <NUM> of the first engages with the thread <NUM> of the second. Therefore, once the gripping tool <NUM> is made integral with the fixing screw <NUM>, this is further rotated so as to unscrew the stem <NUM> of the screw <NUM> from the bone fragment <NUM>' or <NUM>" in which it was inserted.

Once the stem <NUM> of the screw <NUM> has been unscrewed from the bone fragment <NUM>' or <NUM>", the screw itself - which still has its head <NUM> screwed to the gripping tool - is removed and extracted through the effected skin incision.

Conveniently, it is understood that these operations are carried out for each screw <NUM> used to fix the plate <NUM> to the bone fragments <NUM>' and/or <NUM>".

Once all the fixing screws <NUM> have been removed, the plate can be easily removed by pulling it out and passing it through one of the incisions made to remove the screws themselves, possibly after having slightly widened at least one of said incisions.

Advantageously, as stated, in order to remove the internal mechanical fixing system <NUM>, the adapter <NUM> which transforms the screwing tool <NUM> into a gripping tool <NUM> can be used. With this scope, therefore, first the stem <NUM> of the screwing tool <NUM> is inserted in the tubular stem <NUM> of the adapter <NUM> and, with these two instruments thus joined, the screw <NUM> to be removed is approached.

Conveniently, moving away the tubular end portion <NUM> of the adapter <NUM> (for example holding it raised with a finger), from the tip <NUM> of the screwing tool <NUM>, makes so that said tip <NUM> engages within the recessed and shaped mark <NUM> of the head <NUM> of the screw <NUM> to be removed.

Thus, when the stem <NUM> of the screwing tool <NUM> is aligned with the screw <NUM>, i.e. when the tip <NUM> of the first is well inserted into the shaped recessed marks <NUM> of the second, the tubular end portion <NUM> of the adapter <NUM> is approached to the head <NUM> of the screw <NUM> and the female thread <NUM> of said portion <NUM> is screwed to the threads <NUM> provided on the external side wall <NUM> of the head <NUM> of the screw <NUM>. In particular, for this scope, the adapter <NUM> is rotated counter-clockwise until its tubular end portion <NUM> comes into contact with the upper surface of the plate <NUM>. Therefore, once the adapter <NUM> is made integral with the fixing screw <NUM>, said adapter is further rotated - in a manner substantially corresponding to those described above for the gripping tool <NUM> - so as to unscrew the stem <NUM> of the screw from the fragment bone <NUM>' or <NUM>" in which it was inserted.

Advantageously - in contrast to the traditional system of the type Fixin, wherein the through holes on the plate are internally threaded to allow the screwing of corresponding compasses - in the solution according to the present invention, the through holes <NUM> of the plate <NUM> are conical and are substantially smooth/polished internally (i.e. not threaded). This is particularly advantageous since the smooth conical hole <NUM> is easier to clean, while the threaded hole of the Fixin implant must be cleaned and disinfected with extreme care since otherwise it could cause infections; in particular, the Fixin implant plate with the internally threaded holes must be thoroughly cleaned and sterilized in order to eliminate the biological material that is inserted between the threads and which is the trigger for biofilms that infect the system itself.

It can happen that the operator who has chosen a plaque, after it has been positioned in correspondence with the area to be treated (and hence after provoking the contact of the plate itself with the biological material), sees that the choice plate is not suitable for that specific surgical treatment and, therefore, may decide to remove it immediately. However, in this situation, the plate - which has already come into contact with the biological material of the patient - or is definitively discarded, thus causing an undesirable waste, or - to be reused - must be properly cleaned by removing and washing all the compasses, then washing the plate itself and finally reassembling the compasses on the plate.

Therefore, it can be understood how - in this context - the present solution is more advantageous since, as mentioned, the fact that the plate <NUM> has non-threaded conical holes <NUM> makes its cleaning quicker, easier and simpler.

Advantageously, the kit <NUM> according to the invention also comprises a tensioning device <NUM> which comprises two members <NUM> and <NUM> connected together so as to allow their mutual approach/removal, thus generating a greater or inferior tension.

Conveniently, once the two members <NUM> and <NUM> are fixed to the respective bone fragments <NUM>' and <NUM>" to be joined, the actuation of the tensioning device <NUM> causes the two members <NUM> and <NUM> to move closer together, and thus the compression (also called "interfragmentary compression") at the contact area <NUM> (which consists for example of the fracture gap) between the bone fragments to which these organs are fixed.

In particular, as is known, the intra- fragmentary bone compression allows important biological and mechanical advantages for the osteosynthesis operation and, more precisely, favours the neovascularization of the bone fragments at their union zone. In fact, more in detail, from a mechanical point of view, the intra-fragmentary compression causes and increases the adherence of the bone heads and the stability of the system envisaged for the healing of the fracture, thus minimizing the play and the excursion of the fracture gap, reducing also considerably the static and dynamic stresses on the system; furthermore, from a biological point of view, the union of the bone fragments stimulates and promotes the cooperation between the blood vessels of the respective bone fragments. For these reasons, interfragmentary bone compression is highly recommended when an osteosynthesis operation has already failed.

Currently, to cause interfragmentary compression is already known to use a special plate that has one or more dedicated and eccentric holes in which engage the fixing screws. However, this known system makes it possible to obtain a distance between the bone fragments of about <NUM> or a maximum of <NUM> (in the case of two eccentric holes straddling the fracture gap to be joined). This is not always sufficient and, in particular, there are cases in which there is a need to create approach displacements between the bone fragments, in correspondence of the metaphysis area, for example greater than <NUM> (in particular of <NUM>- <NUM>).

Moreover, currently, in order to cause intra- fragmentary compression, a dedicated tensioning device is generally used which is exclusively designed to create the desired compression situation between the bone fragments and, once reached, this position is maintained by inserting traditional fixing screws. In particular, a known tensioning device requires the use of a plate which is positioned straddling the fracture gap (or bone fragments to be joined); therefore, a first extremal portion of the plate is fixed to a first fragment bone with one or more fixing screws, while on the other end portion of the plate - which acts on the second bone fragment to be joined - a bracket is attached and fixed which is connected by a rotating bolt to a guide slider for a nail that is inserted into the second bone fragment to be joined. Then, by rotating the bolt, the bracket hooked to the plate (and fixed to the second bone fragment by means of the nail) causes the movement of the first fragment towards the second fragment through the plate and then the bone compression between them.

This known tensioning device is not completely satisfactory since it is rather complicated and laborious to use. Moreover, this device is rather invasive and, in particular, requires that the plate is oversized in length so that it has dedicated areas for attaching the bracket of the tensioning device, areas which are currently distinct from those provided for insertion of the fixing screws.

Furthermore, when there are other tissues around the bone fragments, such as muscles or ligaments, there is a need to move the tensioning device so as to move it away from the plate. However, the various already known tensioning devices are not suitable to be easily moved towards or away from the outer surface of the plate.

In this context, another object of the invention is to provide an improved kit for orthopedics, preferably for osteosynthesis, which comprises a tensioning device which overcomes the drawbacks of traditional solutions and is an improvement and/or alternative to these.

Another object of the invention is to provide an improved kit for orthopedics, preferably for osteosynthesis, which includes a tensioning device which is simple, quick and easy to use, less invasive and also is vertically movable towards/away from the outer surface of the plate.

Another object of the invention is to provide an improved kit for orthopedics, preferably for osteosynthesis, which leaves the surgeon great freedom, during the operation, on the choice of where to apply the tensioning device.

Conveniently, in the tensioning device <NUM> of the kit <NUM> according to the invention, the two members <NUM> and <NUM> are connected together by a single connecting element <NUM> which, preferably, is bolt-shaped (as shown in <FIG>, <FIG>); however, it is intended that the two members <NUM> and <NUM> can be connected by means of an assembly of more mechanical components, assembly that is configured to approach/remove the two organs from each other, like for example these provided in a traditional turnbuckle in which there are two threaded bodies which are complementarily screwed/unscrewed within a sleeve.

Preferably, the connecting element <NUM>, substantially configured as a bolt, comprises a rod, which is wholly or mainly threaded, and one or more head portions <NUM> suitably shaped so as to be engaged by suitable tools (for example a key) or knob-shaped so as to allow the operator to make the operation by hand, and this in order to rotate (and therefore screw/unscrew) the connecting element <NUM> with respect to an internally threaded sleeve provided in at least one of the two members <NUM>, <NUM> of the tensioning device <NUM> and thus allow the approaching/removal of said two members <NUM>, <NUM>, and therefore of the corresponding bone fragments <NUM>' and <NUM>".

In particular, in the tensioning device <NUM> according to the invention at least one of said two members <NUM>, <NUM> is configured to be associated with said plate <NUM> at the head <NUM> of a screw <NUM> which, passing through a conical through hole <NUM> provided in said plaque, fix the latter to a corresponding bone fragment <NUM>' and/or <NUM>". Preferably, at least one of said two members <NUM>, <NUM> is configured to be associated with said plate <NUM> by means of the gripping tool <NUM> that engages with the female thread <NUM> of its tubular end portion <NUM> on the thread <NUM> of the head <NUM> of the screw <NUM> that, by passing through a conical through hole <NUM> provided in said plate, secures the latter to a corresponding bone fragment <NUM>' and/or <NUM>".

Conveniently, the first <NUM> and/or the second <NUM> member are associated - by the gripping tool <NUM> - with the head <NUM> of a screw <NUM> which fixes the plate <NUM> to a bone fragment.

Advantageously, it is understood that the gripping tool <NUM> used in combination with the tensioning device <NUM> can be an instrument different and separated from the screwing tool <NUM>, or it can comprise the adapter <NUM> - as described above - which transforms the screwing tool <NUM> into said gripping tool <NUM>.

Advantageously, the tensioning device <NUM> according to the invention comprises two members <NUM> and <NUM> which are connected to each other by means of the connecting element <NUM> which is configured to cause the mutual approach/removal of said members, and in which:.

Preferably, as mentioned, the first member <NUM> and the second member <NUM> are connected to each other by the connecting element <NUM>. In particular, for this purpose, the first member <NUM> and the second member <NUM> have respective sleeves <NUM> intended to be crossed by the connecting element <NUM>.

Suitably, the sleeve <NUM> of one of said members <NUM>, <NUM> is internally threaded to allow engagement of the threaded portion of the connecting element <NUM> while the body of the other sleeve <NUM>, <NUM> is internally smooth (i.e., non-threaded); however, it is understood that the sleeves of both members <NUM>, <NUM> can be internally threaded or they can both be internally smooth (i.e. not threaded).

Preferably, the sleeve <NUM> of the first member <NUM> is internally smooth so that the rod (with its threaded or even non-threaded portion) of the connecting element <NUM> passes through this sleeve without any screwing engagement being defined, thus allowing the free sliding of the rod within this sleeve.

In addition, the first member <NUM> has a first tubular section <NUM> configured for the crossing and the guidance of the gripping tool <NUM>. In particular, this tubular portion is destined to be positioned on the outer surface of the plate <NUM> in correspondence with a conical through hole <NUM> of the latter traversed by a fixing screw <NUM>. More in detail, this first tubular section <NUM> of the first portion is dimensioned so as to house it inside the head <NUM> of the fixing screw <NUM> once the tubular end portion <NUM> of the gripping tool <NUM> has been screwed onto the head of said fixing screw <NUM>. In substance, the diameter of the first tubular section <NUM> is slightly larger than the diameter of the tubular end portion <NUM> of the gripping tool <NUM> and this in order to allow a stable positioning of said portion of the instrument taken within said section.

Advantageously, the first tubular section <NUM> has a side opening <NUM> to visually check the engagement between the tubular end portion <NUM> of the gripping tool <NUM> and the head <NUM> of the fixing screw <NUM>.

Conveniently, a suitable symbol <NUM> is also shown on the tubular end portion <NUM> of the gripping tool <NUM> to indicate the direction of rotation of the gripping tool <NUM> in order to cause/allow its engagement on the head <NUM> of the fixing screw <NUM>.

Conveniently, in the first member <NUM> the sleeve <NUM> is integral with the first tubular section <NUM> and they are disposed at an angle. Preferably, in the first member <NUM>, the axes which pass respectively through the sleeve <NUM> and the first tubular section <NUM> are arranged in a substantially perpendicular manner to each other.

Preferably, the sleeve <NUM> and the first tubular section <NUM> of the first member <NUM> are obtained from a single piece or can be made in two distinct pieces rigidly coupled (e.g. by welding) to each other.

The second member <NUM> includes a second tubular section <NUM> configured for crossing and the guidance of a nail <NUM> destined to be inserted in a corresponding cavity formed in one of the fragments of a bone.

Suitably, the second member <NUM> the sleeve <NUM> is integral with the second tubular section <NUM> and, preferably, are disposed at an angle between them. Preferably, in the second member <NUM>, the axes which pass respectively through the sleeve <NUM> and the second tubular section <NUM> are arranged in a substantially perpendicular or slightly angled manner to each other; appropriately, in this way, the angle defined between the connecting element <NUM> and the nail <NUM> can be substantially equal to or even lower than <NUM>°.

Preferably, the sleeve <NUM> and the second tubular section <NUM> of the second member <NUM> are formed in a single piece or can be formed in two distinct pieces made integral (for example by welding) between them.

Conveniently, by sliding the tubular sections <NUM> and <NUM>, of the first and second member <NUM> and <NUM> respectively, along the stem of the gripping tool <NUM> and along the nail <NUM> respectively it is possible to move away the tensioning device <NUM> (comprising said members <NUM> and <NUM> with the connecting element <NUM>) with respect to the upper surface of the plate <NUM>, thus allowing access to the bone fragments even when around these other tissues, such as muscles or ligaments to be preserved are present. Conveniently, in the section of the connecting element <NUM> interposed between the two members <NUM> and <NUM> a tightening nut (not shown) may be provided on which to act to separate said organs, and therefore the respective bone fragments, from each other; acting instead at the head portion <NUM>, the two members <NUM> and <NUM> and therefore of the corresponding bone fragments <NUM>', <NUM>" are brought closer together.

The use of the tensioning device <NUM> to cause the compression of two bone segments <NUM>', <NUM>" at their contact area <NUM> is the following :.

Claim 1:
Improved kit (<NUM>) for orthopedics, preferably for osteosynthesis, comprising an internal mechanical fixing system (<NUM>) which includes a plate (<NUM>) to be mounted straddling two bone fragments to be joined (<NUM>', <NUM>") and at least two, preferably at least four, fixing screws (<NUM>) for fixing the plate to said two bone fragments (<NUM>', <NUM>"), wherein:
- said plate (<NUM>) consists of a plate made of biocompatible metal material and has a thickness of about <NUM> - <NUM>, said plate (<NUM>) being provided with at least two, preferably at least four, conical through holes (<NUM>) whose inner walls (<NUM>) are obtained with at least one surface finishing mechanical operation,
- each of said at least two fixing screws (<NUM>) has a head (<NUM>) and a self-tapping stem (<NUM>), and wherein each of said at least two fixing screws (<NUM>):
- comprises a conical collar (<NUM>) which is interposed between said head (<NUM>) and said self-tapping stem (<NUM>) and is configured to define a conical coupling within a corresponding conical through hole (<NUM>) of the plate (<NUM>), the head (<NUM>) presenting on its upper surface a recessed and shaped mark (<NUM>) for the coupling by the, at least partial, shape coupling, of the tip (<NUM>) of a screwing tool (<NUM>) and said head (<NUM>) also presenting on its external side wall (<NUM>) a thread (<NUM>) for the engagement of a gripping tool (<NUM>),
- is configured so that, when its conical collar (<NUM>) is inserted into a corresponding conical through hole (<NUM>) of the plate (<NUM>), said head (<NUM>) protrudes outwards with respect to said plate (<NUM>),
- comprises a flange (<NUM>) connecting the head (<NUM>) with the collar (<NUM>), said flange (<NUM>) being configured to be spaced with respect to the outer surface of the plate (<NUM>) when the conical collar (<NUM>) of the fixing screw (<NUM>) is inserted within a conical through hole (<NUM>) of the plate itself.