Patent Description:
In particular, the present invention relates to a device for tensioning a surgical thread which can be used in the orthopedic field to carry out operating techniques for the cerclage of fractured bones.

Cerclage basically consists of winding a surgical thread (or cable) about two or more parts of a patient's fractured bone to hold them together and prevent the separation thereof.

The most common surgical techniques to date include, after having incised the patient at the bone to be operated on, the use of a passer instrument (or even simply referred to as a "passer") for cerclage which allows a surgical thread made of stainless steel to be passed about the fractured bone so as to circumnavigate it.

The passer is then removed, and the two ends of the thread can now be fixed on opposite arms of a special surgical instrument having the function of first tensioning, and then twisting, the two ends of the thread.

The surgeon inserts the aforementioned instrument into the wound, placing it against the bone, and fixes the two ends of the thread at the respective arms of the instrument. At that point, by manually activating appropriate tensioning means, the surgeon pulls the two ends of the thread until they are tensioned according to a given tension.

Now that the ends of the thread are properly tensioned, the surgeon can rotate the instrument about an axis perpendicular to the bone to twist the thread at the bone, so as to fix the thread to the bone, thus creating the so-called cerclage.

In fact, after a few turns of the instrument, the thread wound about the bone remains tightened about the bone, so it is no longer necessary to apply tension to the thread, which is why at this point it is possible to extract the instrument and cut the excess part of the thread.

Although the cutting step allows removing most of the excess thread, it is however necessary to leave a "snag" (i.e., a sharp protrusion) of twisted thread of adequate size in the patient's body, so that the thread does not untie when the cerclage obtained fails.

In fact, since it is not possible to stably fasten a metal surgical thread by obtaining a knot (due to the high surface smoothness of the metal), it is necessary to proceed with the twisting, with the consequent need to leave a fastening snag inside the patient's body.

However, the Applicant has observed how this metal snag protruding from the bone can cause pain, injury, and lacerations in the surrounding soft tissues.

The Applicant has found that the use of a thread made of softer material, instead of metal, could overcome such drawbacks connected to the presence of the snag.

However, a softer thread cannot be twisted about the bone and then remain in place for stable cerclage, but must be knotted.

However, the creation of a cerclage knot would require a larger wound (or the need to widen the wound with obvious negative consequences for the patient) in order to allow the surgeon to pull the two ends of the thread and tighten the loop about the fractured bone. In fact, to obtain an effective tensioning of the thread so as to tighten the knot on the bone, the two ends of the thread must be pulled in opposite and parallel directions, for which a considerable maneuvering space around the bone would be necessary.

The wound which is made in the patient is basically minimal to allow the operation to be carried out as noninvasively as possible; furthermore, the bone is surrounded by soft tissues whereby the maneuvering space is very limited. Therefore, an effective thread tensioning according to this technique is neither advisable nor easily practicable.

<CIT> discloses a tensioning apparatus for applying a predetermined level of tension to a cable looped about tissue portions, which comprises: a handle; an elongated member extending from the handle and defining a longitudinal axis; first and second cable engaging pawls mounted to the elongated member for releasably engaging respective ends of the cable; a movable grip mounted to the handle; and an actuating member connected to the movable grip and adapted to longitudinally translate upon movement of the movable grip, the actuating member operatively connected to the cable engaging pawls whereby movement of the movable grip causes corresponding movement of the cable engaging pawls to tension the cable.

In this context, it is the technical task underlying the present invention to suggest a device for tensioning a surgical thread and a bone cerclage kit which overcome one or more of the drawbacks of the prior art mentioned above.

In particular, it is an object of the present invention to provide a device for tensioning a surgical thread which is small in size and which allows tensioning a surgical thread wound about a patient's bone in the smallest possible space in a practical and effective manner.

It is a further object of the present invention to suggest a bone cerclage kit which allows obtaining a reliable, minimally invasive cerclage which protects the patient's health (in particular the integrity of the soft tissues surrounding the bone).

The technical task and the specified objects are substantially achieved by a device for tensioning a surgical thread comprising the technical features set forth in one or more of the appended claims.

In particular, the present invention provides a device, as defined in the claims, for tensioning a surgical thread comprising an elongated body and a maneuvering member.

The elongated body extends along a longitudinal axis and has a tip portion adapted to be arranged in contact with a knot of a surgical thread wound about a patient's bone.

The maneuvering member is connected to the elongated body and is adapted to be arranged outside the patient's body.

In particular, the elongated body is connected to the maneuvering member by means of a screw and nut-screw mechanism configured to mutually space apart or approach the elongated body and the maneuvering member.

The elongated body has respective coupling portions configured to couple opposite ends of the surgical thread wound and knotted about the bone.

The opposite ends of the surgical thread can be reversibly constrained to the respective coupling portions in a use configuration of the device.

The elongated body and the maneuvering member can be mutually spaced apart along a movement axis coinciding with the longitudinal axis of the elongated body in order to tension the opposite ends of the surgical thread so as to tighten the surgical thread about the bone.

In other words, by spacing the elongated body apart from the maneuvering member, the two opposite ends of the thread are pulled, thus tightening the knot.

Advantageously, the tip portion has a groove shaped to receive at least partially the knot in the use configuration of the device.

The groove extends perpendicular to the movement direction to open on opposite sides of a sidewall of the elongated body at respective return portions along which the opposite ends of the surgical thread can be returned toward the coupling portions.

In other words, the groove defines a through indent of the tip portion adapted to face the bone in the use configuration of the device.

Advantageously, the opposite ends of the surgical thread can thus be arranged tangentially to the bone over a first stretch between the return portions inside the groove, and transversely to said bone along respective second stretches, having a greater length than the first stretch, between the return portions and the coupling portions.

Therefore, by virtue of the device of the present invention, by pulling the two ends of the thread along the second stretches (transversal to the bone surface), it is possible to effectively tighten the knot arranged in the groove about the bone, since inside the first stretch (connected at the second stretches) the two ends of the thread are tensioned along opposite and parallel directions.

Therefore, the traction exerted on the knot by the ends of the thread pulled in the first stretch of small size is very effective due to the favorable distribution of the applied forces; such a traction is returned in the second stretches to advantageously operate in a small volume.

Therefore, the presence of a first stretch tangential to the bone allows an efficient tensioning of the thread which is transferred to the second stretches in the smallest possible space.

In other words, by virtue of the device of the present invention, it is therefore possible to pull the surgical thread horizontally (in a small stretch) while applying a vertical traction (along stretches of large dimension) in the smallest possible space.

The presence of the groove on the tip portion allows tightening the knot effectively.

Furthermore, by virtue of the present device it is possible to carry out a cerclage starting from a knot obtained by winding the surgical thread about the bone to be operated on.

In fact, instead of twisting the thread, by operating on a knot it is possible to make the cerclage more effective by reducing the risk of untying and to allow the use of a thread made of soft material which can prevent tearing the surrounding soft tissues during and after the operating steps.

According to a further aspect of the present invention, a bone cerclage kit as defined in claim <NUM> is also provided, comprising a surgical thread made of biocompatible fabric configured to be wound about a patient's bone to obtain a knot, and a device for tensioning said surgical thread in accordance with the present invention.

Advantageously, the groove of the tip portion is configured to be arranged in contact with the knot in the use configuration of the device.

The thread in biocompatible fabric is a soft thread which has many advantages, including the possibility of not damaging the bone and surrounding tissues.

By virtue of the use of a surgical thread made of biocompatible fabric and the tensioning device according to the present invention, it is therefore possible to achieve an effective cerclage of the bone using a knot, which is much more reliable than a twisted thread.

Once the knot has been tightened about the bone, it is possible to use simple surgical scissors to remove the excess thread from the two ends, leaving only a small knot in sight, which being made of fabric will prevent injuries and lacerations of the surrounding tissues.

Surgical scissors are also less bulky and much more maneuverable than surgical forceps, therefore the operation of cutting and removing the excess thread is practical and efficient by virtue of the present invention.

Therefore, the presence of a knot allows a safer and more stable cerclage which does not require a bulky and dangerous "snag.

The kit of the present invention allows operating in a minimally invasive manner, achieving an efficient cerclage.

The dependent claims, incorporated by reference herein, correspond to different embodiments of the invention.

Further features and advantages of the present invention will become more apparent from the following indicative and thus non-limiting description of a preferred, but not exclusive, embodiment of a device for tensioning a surgical thread and a bone cerclage kit, as shown in the accompanying drawings, in which:.

With reference to the accompanying drawings, reference numeral <NUM> indicates as a whole a device for tensioning a surgical thread, hereinafter simply device <NUM>.

The device <NUM> comprises an elongated body <NUM> and a maneuvering member <NUM>.

The elongated body <NUM> extends along a longitudinal axis Y and has a tip portion <NUM> adapted to be arranged in contact with a knot <NUM> of a surgical thread <NUM> wound about a patient's bone B, for example a damaged bone B (such as diagrammatically shown in <FIG>).

Preferably the knot <NUM> is obtained in contact with the bone B, i.e., the thread <NUM> is knotted so that the knot <NUM> is arranged in contact with the surface of the bone B.

The maneuvering member <NUM> is connected to the elongated body <NUM> and is adapted to be arranged outside the patient's body when using the device <NUM> (i.e., outside the wound) and has respective coupling portions <NUM> for coupling opposite ends <NUM> of the surgical thread <NUM> wound and knotted about the bone B.

The opposite ends <NUM> of the surgical thread <NUM> can be reversibly constrained to the respective coupling portions <NUM> in a use configuration of the device <NUM>.

In particular, the elongated body <NUM> and the maneuvering member <NUM> can be mutually spaced apart along a movement axis X coinciding with the longitudinal axis Y in order to tension the opposite ends <NUM> of the surgical thread <NUM> so as to tighten the surgical thread <NUM> about the bone B.

In other words, in the use configuration of the device <NUM>, by spacing apart the elongated body <NUM> (the tip portion <NUM> of which is arranged in contact with the knot <NUM>) and the maneuvering member (to which the opposite ends <NUM> of the thread <NUM> is fastened at the respective coupling portions <NUM>) along the movement axis X, it is possible to tension the opposite ends <NUM> causing the knot <NUM> to approach the bone B and a consequent tightening of the knot <NUM>.

Advantageously, the tip portion <NUM> has a groove <NUM> shaped to receive at least partially the knot <NUM> in the use configuration of the device <NUM>.

The groove <NUM> extends perpendicularly to the movement axis X along an extension direction <NUM>' to open on opposite sides of a sidewall <NUM> of the elongated body <NUM> at respective return portions <NUM>, along which the opposite ends <NUM> of the surgical thread <NUM> can be returned toward the coupling portions <NUM>.

Thereby, the opposite ends <NUM> of the surgical thread <NUM> can be arranged tangentially to the bone B over a first stretch (clearly visible in <FIG>) between the return portions <NUM> inside the groove <NUM>, and transversely to the bone B along respective second portions, having a greater length than the first stretch, between the return portions <NUM> and the coupling portions <NUM>.

According to the present invention, the elongated body <NUM> is connected to the maneuvering member <NUM> by means of a screw and nut-screw mechanism <NUM> configured to mutually space apart or approach the elongated body <NUM> and the maneuvering member <NUM>.

Advantageously, the use of a screw and nut-screw mechanism <NUM> allows precisely adjusting the mutual distance between the two elements to obtain a progressive tensioning of the opposite ends <NUM> of the thread <NUM>, as will become apparent in the following description.

The maneuvering member <NUM> comprises a knob <NUM> which can be rotated about the movement axis X to screw or unscrew the screw and nut-screw mechanism <NUM>, and a sleeve <NUM> on which the two coupling portions <NUM> are obtained.

In particular, with reference to the embodiment shown in <FIG>, the two coupling portions <NUM> are obtained on opposite sides of the sleeve <NUM> with respect to a direction parallel to the extension direction <NUM>' of the groove <NUM>.

Advantageously, the knob <NUM> is rotationally connected to the sleeve <NUM>.

Even more preferably, the elongated body <NUM> and the sleeve <NUM> are mutually translatable along the movement axis X and rotationally fixed about the movement axis X.

In other words, the elongated body <NUM> and the sleeve <NUM> can be mutually spaced apart and approached along the movement axis X but they cannot be rotated with each other, therefore the coupling portions <NUM> are fixed with respect to the rotation of the knob <NUM> of the maneuvering member <NUM>. Preferably, the elongated body <NUM> comprises a head element <NUM> on which the tip portion <NUM> is obtained, and a stem <NUM> extending along the longitudinal axis Y and operatively interposed between the head element <NUM> and the maneuvering member <NUM>.

In other words, the head element <NUM> and the knob <NUM> are arranged on opposite sides along the movement axis X of the device <NUM>.

Preferably, the stem <NUM> has a first end 16a inserted inside a respective recess 24a of the maneuvering member <NUM> and a second end 16b, opposite the first end 16a, inserted in a respective recess 15b of the head element <NUM>, axially opposite to said tip portion <NUM>.

In other words, the head element <NUM> has a recess 15b extending along the longitudinal axis Y and open on the axially opposite side of the head element <NUM> with respect to the tip portion <NUM>; likewise, the sleeve <NUM> has a recess 24a extending along a direction coinciding with the movement axis X and open on the axially opposite side of the sleeve <NUM> to the knob <NUM>.

Advantageously, therefore, the stem <NUM> can be moved between the respective recesses 24a, 15b to obtain the mutual spacing apart of the elongated body <NUM> and the maneuvering member <NUM>.

Preferably, moreover, with reference to the embodiment shown in <FIG>, the screw and nut-screw mechanism <NUM> comprises a nut-screw <NUM>, fixed to the first end 16a of the stem <NUM>, and a screw <NUM>, arranged along the movement axis X and fixed inside the respective recess 24a of the maneuvering member <NUM>.

In particular, the screw <NUM> is reversibly screwable on the nut-screw <NUM> to allow the translation of the stem <NUM> so as to obtain the mutual spacing apart or approaching of the maneuvering member <NUM> and the elongated body <NUM>.

Furthermore, the sleeve <NUM> is preferably coupled to the knob <NUM> by means of a dowel <NUM> arranged inside the recess 24a.

Preferably the device <NUM> comprises a spring <NUM> operatively interposed between a flange 16c of said stem <NUM> and a shoulder 15c defined by an outer edge of said head element <NUM>.

The spring <NUM> is advantageously configured to oppose the advancement of the stem <NUM> inside the respective recess 15b of the head element <NUM> toward the tip portion <NUM>.

In other words, the spring <NUM> is configured to oppose the mutual spacing apart between the elongated body <NUM> and the maneuvering member <NUM>, and in particular the unscrewing of the nut-screw <NUM> from the screw <NUM> with reference to <FIG>.

Furthermore, the device <NUM> preferably comprises a system <NUM> for detecting and indicating the tension value to which the thread <NUM> is subjected in the use configuration of the device <NUM>. Advantageously, by virtue of the system <NUM>, the surgeon can therefore monitor whether the tension applied to the thread <NUM> is adequate in real time.

Even more preferably the head element <NUM> has a window 15a through which a portion of stem <NUM> inserted in the respective recess 15b of the head element <NUM> is visible. The detection and indication system <NUM> further comprises indicators 3a, 3b obtained on the stem <NUM> (a notch in the embodiment in <FIG>, or a pin in the embodiments in <FIG> and <FIG>) and on the window 15a (for example a graduated scale with the indication of the tension expressed in Newtons of the force applied in the embodiments in <FIG> and <FIG>, or a series of notches in the embodiment in <FIG>), respectively, and representative of a tension value of the spring <NUM> and/or of an insertion depth value of the stem <NUM> in the recess 15b of the head element <NUM>.

Advantageously, therefore, the surgeon can have rapid feedback of the tension value of the thread <NUM> in order to compare the values detected by the indicators 3a, 3b with predetermined reference values.

For example, the optimal thread tension which the surgeon can achieve with the device <NUM> is <NUM> N.

According to the present invention, moreover, the sidewall <NUM> of the elongated body <NUM> preferably has two slots <NUM>, each slot <NUM> departing from a respective return portion <NUM> along a respective extension direction directed toward a respective coupling portion <NUM>, so that the groove <NUM> and the two slots <NUM> define a single "U"-shaped groove of the elongated body <NUM>.

Advantageously, the slots <NUM> allow a housing guide to be obtained for the opposite ends of the thread <NUM> directed toward the coupling portions <NUM>, so that in the use configuration of the device <NUM> they do not slip off the tip portion <NUM>.

Preferably, with reference to the embodiment in <FIG>, the extension directions of the slots <NUM> are parallel to the movement axis X.

Preferably the return portions <NUM> define rounded connecting edges between the groove <NUM> and the two slots <NUM> so as to avoid the onset of localized tensions at any edges.

Preferably, the tip portion <NUM> further has a secondary groove <NUM> extending transversely, preferably perpendicularly, to the groove <NUM> along a respective extension direction <NUM>'.

The secondary groove <NUM> is advantageously shaped so as to receive at least partially the knot <NUM> at an intersection point, not visible in the accompanying drawings, with the groove <NUM>.

Advantageously, moreover, the secondary groove <NUM> extends perpendicularly to the movement axis X to open on opposite sides of the sidewall <NUM> of the elongated body <NUM> at two openings <NUM> for the passage of the part <NUM> of thread <NUM> wound about the bone B.

Preferably, the two openings <NUM> are angularly spaced by <NUM>° with respect to the return portions <NUM> with respect to the intersection point between the two grooves <NUM>, <NUM>.

In other words, the secondary groove <NUM> is also adapted to receive the knot <NUM> at least partially and to house the part <NUM> of thread <NUM> wound about the bone B, so that the opposite ends <NUM> of the thread <NUM> are arranged inside said groove <NUM> perpendicular to said part <NUM>.

<FIG> and <FIG> refer to two alternative embodiments of the present invention in which the screw and nut-screw mechanism <NUM> is obtained differently than that of the device in <FIG>. Preferably, in fact, as clearly seen in <FIG>, <FIG> and <FIG>, the knob <NUM> has an inner threaded portion 22a and the first end 16a of the stem <NUM> is threaded to be reversibly screwed inside the inner threaded portion 22a to allow the translation of the stem <NUM> so as to obtain the mutual spacing apart or approaching of the maneuvering member <NUM> and the elongated body <NUM>.

Advantageously, the first threaded end 16a and the inner threaded portion 22a define the screw and nut-screw mechanism <NUM>, in which in particular the first threaded end 16a functions as a "screw" while the inner threaded portion 22a functions as a "nut-screw".

In other words, by unscrewing the knob <NUM> the first end 16a of the stem <NUM> will be moved in extraction from the respective recess 24a of the maneuvering member <NUM>, in particular in this case the recess 24a is obtained in the knob <NUM>.

Preferably, the knob <NUM> is rotationally connected to the sleeve <NUM> at two anti-extraction blocks 23a.

The spring <NUM> is preferably arranged inside the sleeve <NUM>. Advantageously, it is thus possible to prevent pinching and accidental contacts with surrounding tissues during the operation on the patient's bone.

Preferably, moreover, the maneuvering member <NUM>, and even more preferably the sleeve <NUM>, comprises an inspection eyelet <NUM> through which the stem <NUM> is visible and in which the stem <NUM> comprises a pin <NUM> which is movable inside the inspection eyelet <NUM> upon the actuation of the screw and nut-screw mechanism <NUM>. In particular, the inspection eyelet <NUM> is associated with visual elements <NUM> representative of the advancement of the stem <NUM>.

Advantageously, therefore, the pin <NUM> allows the surgeon to see how much the stem <NUM> is moving.

With reference to the first alternative embodiment shown in <FIG>, <FIG>, <FIG>, <FIG>, preferably the coupling portions <NUM> comprise two jaws <NUM> which are rotatable about respective parallel rotation axes R to retain the opposite ends <NUM> of the surgical thread <NUM>.

As clearly seen in <FIG>, in particular the jaws <NUM> have respective peripheral portions <NUM> with increasing diameter facing each other to define a throat <NUM> of variable thickness adapted to receive the opposite ends <NUM> under insertion.

The coupling portions <NUM> further comprise two torsional springs, not shown, associated with the respective jaws <NUM> and configured to progressively oppose the discordant rotation of the jaws <NUM> which causes an increase in the thickness of the throat <NUM>.

Advantageously, therefore, the opposite ends <NUM> of the thread <NUM> can be inserted side by side inside the throat <NUM> by forcing the two jaws <NUM> to "open" against the force of the torsional springs, i.e., to rotate in the direction indicated by the arrows F1 in <FIG> so that the thickness of the throat <NUM> increases, allowing the insertion of the opposite ends of the thread <NUM>. At the end of the traction due to the insertion of the two opposite ends <NUM> between the jaws <NUM>, the two peripheral portions <NUM> will rotate in the opposite direction with respect to the arrows F1 under the return force of the torsional springs to "close" the jaws <NUM>, i.e., to decrease the thickness of the throat <NUM> until the two opposite ends <NUM> remain crushed and retained trapped in the peripheral portions <NUM>.

In other words, the jaws <NUM> are shaped like cams and the coupling portions <NUM> substantially define a cam-cleat mechanism.

Advantageously, the cam-cleat mechanism thus defined prevents the thread <NUM> from slipping out of the jaws <NUM> in the opposite direction to that of insertion and ensures an excellent coupling and retaining element of the cable for tensioning the opposite ends <NUM>.

The coupling portions <NUM> thus formed are configured as a practical and efficient tool for tensioning the thread <NUM>.

With particular reference to <FIG>, preferably each peripheral portion <NUM> has a first part <NUM> defining the throat <NUM> and a second part <NUM> having a series of retaining indents <NUM>, preferably of constant thickness, obtained transversely to the rotation axes R of the jaws <NUM> between which open return and positioning recesses <NUM> of the opposite ends <NUM> of the thread <NUM> are interposed.

Preferably, the first part <NUM> has a toothed profile, so as to improve the retaining capacity of the thread <NUM>.

Advantageously, the opposite ends <NUM> can be inserted, upon the application by the surgeon of a certain traction force, in sequence inside the open return and positioning recesses <NUM> passing through respective retaining indents <NUM>, so as to direct the ends <NUM> towards predetermined directions.

Preferably, the thickness of the retaining indents <NUM> is less than or equal to the diameter of the thread <NUM>.

Advantageously, the surgeon, after having arranged the tip portion <NUM> of the elongated body <NUM> against the knot <NUM>, can proceed with the insertion of the opposite ends <NUM> inside the throat <NUM> (<FIG>).

<FIG> and <FIG> show an operating configuration of the device <NUM> in which the thread <NUM> beyond the knot <NUM> is slack, so that the two opposite ends <NUM> are not under tension but slack, the spring <NUM> is at rest, the knob <NUM> is completely screwed on the first end 16a. In this configuration, the pin <NUM> is arranged at the beginning of the inspection eyelet <NUM> and the pin 3a is arranged at the beginning of the window 15a, at the indicator 3b which marks "<NUM>".

In other words, the stem <NUM> has not yet moved and the tension detected by the detection and indication system is equal to <NUM> (i.e., the opposite ends <NUM> are not tensioned).

Upon the unscrewing of the knob <NUM>, for example upon a rotation of two turns of the knob <NUM> (as shown in <FIG>), the first end 16a is unscrewed from the threaded portion 22a of the knob <NUM> causing a compression of the spring <NUM> and a progressive removal of the head element <NUM> from the sleeve <NUM> which allows the opposite ends <NUM> of the thread <NUM> to be progressively tensioned (therefore the opposite ends <NUM> in this situation are no longer slack). Simultaneously with the advancement of the stem <NUM>, the pin <NUM> advances inside the inspection eyelet <NUM> to indicate to the surgeon the extent of the removal of the stem <NUM> from the first recess 24a.

In particular, with reference to <FIG>, a configuration is shown in which the pin 3a is arranged at the beginning of the window 15a, i.e., at the indicator 3b which marks "<NUM>".

In other words, the stem <NUM> has been moved spaced apart but the tension detected by the detection and indication system is still equal to <NUM> (i.e., the opposite ends <NUM> are not tensioned), this is because the opposite ends <NUM> are no longer slack but are still not tensioned.

Advantageously, the visual elements <NUM> can be in the form of notches to indicate to the surgeon the limit position of the pin <NUM> beyond which, according to the appropriate sizing of the device <NUM>, it will no longer be possible to achieve the predetermined target tension value (for example 400N) of the thread <NUM>, if the pin 3a, when the pin <NUM> has passed such notches, has not yet moved from the indicator 3b which marks "<NUM>".

In other words, if the opposite ends <NUM> have not been correctly coupled and "pre-tensioned" in the jaws <NUM> (i.e., left too slack), unscrewing the entire knob <NUM> will not allow achieving the target value; however, by virtue of the presence of the pin <NUM> and of the visual elements <NUM>, this scenario can be easily overcome by operating a further insertion of the thread <NUM> in the jaws <NUM> before continuing with the unscrewing of the knob <NUM>.

If the surgeon, from the configuration illustrated in <FIG>, proceeds to further unscrew the knob <NUM>, the spring <NUM> compresses further and the stem <NUM> advances further in extraction from the knob <NUM> so that the second end 16b of the stem advances in the respective recess 15b of the head element <NUM>, causing the progressive tensioning of the opposite ends <NUM>.

In this configuration, the pin <NUM> is further advanced in the inspection eyelet <NUM> and the pin 3a is advanced inside the window 15a (<FIG>), indicating the tension value of the opposite ends <NUM> obtained to the surgeon.

With reference to the second alternative embodiment of the device <NUM>, shown in <FIG>, preferably the coupling portions <NUM> comprise two bitt-like elements <NUM> having a through anchoring slot <NUM>, preferably of variable thickness, obtained transversely to the movement direction X.

Advantageously, the opposite ends <NUM> can be wound at least once about the two bitt-like elements <NUM> and subsequently inserted inside the through anchoring slot <NUM> until reaching a depth which obtains the retention of the thread <NUM> by interference.

According to a further aspect of the present invention, a kit for the cerclage of a bone B is further provided, comprising a surgical thread <NUM> in biocompatible fabric, possibly bioabsorbable, configured to be wound about the bone B to obtain the knot <NUM> and a device <NUM> for tensioning said surgical thread <NUM> as previously described, so that the groove <NUM> is configured to be arranged in contact with said knot <NUM> in the use configuration of the device <NUM>.

Operatively, therefore, the surgeon who intends to carry out a cerclage of bone B using the kit provided by the present invention, initially winds the thread <NUM> about the fractured bone B, obtaining the knot <NUM>.

The surgeon then places the tip portion <NUM> of the elongated body <NUM> against the knot <NUM> so that the knot <NUM> is at least partially inserted inside the groove <NUM>. Preferably, the part <NUM> of thread <NUM> wound about the bone B is partially arranged inside the secondary groove <NUM>.

The two opposite ends <NUM> of the thread <NUM> are fastened to the coupling portions <NUM>, preferably passing through the two slots <NUM>.

At this point the surgeon can mutually space apart the elongated body <NUM> from the maneuvering member <NUM> to tighten the knot by pulling the ends so as to tighten the knot <NUM>. In other words, a narrowing of the knot <NUM> is obtained, i.e., a decrease in the part <NUM> of the thread <NUM> which is tightened about the bone B.

Preferably, such an operation occurs by turning the knob <NUM> so as to unscrew the nut-screw <NUM> from the screw <NUM> (for the embodiment in <FIG>) or unscrew the inner threaded portion 22a from the first threaded end 16a of the stem <NUM> (for the embodiments in <FIG> and <FIG>, causing the partial extraction of the stem <NUM> from the recess 24a of the maneuvering member <NUM> and the corresponding advancement of the stem <NUM> inside the respective recess 15b of the head element <NUM> of the elongated body <NUM>.

Advantageously, the knot <NUM> is obtained so as to be irreversibly loosened, so that it is only possible to tighten it.

After having adequately tightened the thread <NUM> about the bone B, preferably with the support of the detection and indication system <NUM>, it is possible to remove the device <NUM> from the patient's body.

Such an operation can preferably be obtained by bringing the elongated body <NUM> closer to the maneuvering member <NUM> to release the tension in the opposite ends <NUM> and subsequently releasing the opposite ends <NUM> from the coupling portions <NUM>.

Finally, the surgeon extracts the device <NUM> from the patient's body and can proceed with cutting the opposite ends <NUM> of the thread <NUM> at the knot <NUM>, on the opposite side with respect to the part <NUM> wound about the bone B.

Claim 1:
A device (<NUM>) for tensioning a surgical thread comprising:
- an elongated body (<NUM>) extending along a longitudinal axis (Y) and having a tip portion (<NUM>) adapted to be arranged in contact with a knot (<NUM>) of a surgical thread (<NUM>) wound about a patient's bone (B), and
- a maneuvering member (<NUM>), connected to said elongated body (<NUM>), adapted to be arranged outside the patient's body and having respective coupling portions (<NUM>) for coupling opposite ends (<NUM>) of said surgical thread (<NUM>) wound and knotted about said bone (B), said opposite ends (<NUM>) of the surgical thread (<NUM>) being reversibly constrainable to said respective coupling portions (<NUM>) in a use configuration of the device (<NUM>);
wherein said elongated body (<NUM>) is connected to said maneuvering member (<NUM>) by means of a screw and nut-screw mechanism (<NUM>) configured to mutually space apart or approach said elongated body (<NUM>) and said maneuvering member (<NUM>);
wherein said elongated body (<NUM>) and said maneuvering member (<NUM>) are configured to be mutually spaced apart along a movement axis (X) coinciding with the longitudinal axis (Y) in order to tension the opposite ends (<NUM>) of the surgical thread (<NUM>) so as to tighten the surgical thread (<NUM>) about the bone (B),
wherein said tip portion (<NUM>) has a groove (<NUM>) shaped to receive at least partially said knot (<NUM>) in the use configuration of the device (<NUM>),
said groove (<NUM>) extending perpendicularly to the movement axis (X) to open on opposite sides of a sidewall (<NUM>) of said elongated body (<NUM>) at respective return portions (<NUM>) along which the opposite ends (<NUM>) of the surgical thread (<NUM>) can be returned toward the coupling portions (<NUM>),
so that the opposite ends (<NUM>) of the surgical thread (<NUM>) can be arranged tangentially to the bone (B) over a first stretch between the return portions (<NUM>) inside the groove (<NUM>), and transversely to said bone (B) along respective second stretches, having a greater length than the first stretch, between the return portions (<NUM>) and the coupling portions (<NUM>);
wherein said maneuvering member (<NUM>) comprises:
- a knob (<NUM>) which is rotatable about the movement axis (X) for screwing or unscrewing the screw and nut-screw mechanism (<NUM>), and
- a sleeve (<NUM>) on which the two coupling portions (<NUM>) are obtained;
said knob (<NUM>) being rotationally connected to said sleeve (<NUM>).