SURGICAL TREATMENT INSTRUMENT

Description

[0001] The invention relates to a surgical treatment instrument, in particular for procedures comprising the section of fibrous tissue such as tenolysis, tenotomy or neurolysis. The invention also relates to an assembly comprising a surgical treatment instrument associated with an insertion cannula and / or a syringe. In addition, the disclosure relates to an insertion cannula (not included as such in the scope of the claims) for a surgical treatment instrument, and to a method of surgical treatment (not included in the scope of the claims), in particular comprising the section of fibrous tissue, such as tenolysis, tenotomy or neurolysis, using a surgical treatment instrument.

[0002] As is known, tenolysis is a surgical procedure involving the section of an adhesion formed at the level of a tendon; tenotomy is a surgical procedure involving the section of a tendon; neurolysis is a surgical procedure involving the section of an adhesion compressing a nerve. An example of a pathology whose surgical treatment involves tenolysis is trigger finger. More specifically, the surgical treatment of trigger finger involves the section of the pulley, i.e. the sheath, which surrounds the flexor tendon, so as to allow the release of the flexor tendon from the pulley. An example of a pathology whose surgical treatment involves neurolysis is carpal tunnel syndrome.Specifically, surgical treatment of carpal tunnel syndrome involves sectioning the anterior annular ligament of the carpus to release the median nerve from the structures that compress it. Procedures involving section of fibrous tissue, such as tenolysis, tenotomies, or neurolysis, can be performed to treat various parts of the body, including the hand, shoulder, knee, ankle, and foot.

[0003] During tenolysis, tenotomy or neurolysis, it is conventional to perform the section of the fibrous tissue using a retro-knife type instrument, having a sharp hook. The hook of the instrument is first introduced at the front of the fibrous tissue, then the instrument is subjected to a translational movement from the front to the back of the fibrous tissue towards an entry incision, so as to section the fibrous tissue. US 2016 / 113671 A1 discloses such an instrument.

[0004] Currently, tenolysis, tenotomies and neurolysis are performed: either openly, by making a large incision involving relatively long and painful post-operative periods, requiring a significant break in activity; or by endoscopy, by making a smaller incision and using different instruments for the introduction stage, which is performed blindly, then for the stage of sectioning the fibrous tissue, which is performed with vision limited to the optics of the endoscope, the post-operative periods remaining relatively long and painful, again requiring a significant break in activity.

[0005] It is these drawbacks that the invention more particularly intends to remedy by proposing an instrument and a method of surgical treatment (not included in the scope of the claims) making it possible to carry out an intervention such as tenolysis, tenotomy or neurolysis with a single instrument, in a single movement and with a single hand, thus being compatible with monitoring using a device held in the other hand, such as an ultrasound probe, while limiting post-operative pain and the duration of downtime.

[0006] For this purpose, according to one aspect, the invention relates to a surgical treatment instrument according to claim 1, in particular for tenolysis, tenotomies or neurolysis, comprising a main body and a distal part, where the distal part comprises a curved portion forming a hook and is provided with a cutting blade on the inner side of the hook, the main body comprising a longitudinal lumen for the passage of fluid from a proximal end to a distal end of the main body, the main body further comprising a concavity elbow facing the same side as the hook.

[0007] The claimed surgical treatment instrument is such that the main body comprises, in the vicinity of its distal end, an injection channel which is in fluid connection with the lumen via a pressure relief chamber. The injection channel is intended to direct a jet of fluid above the hook and the pressure relief chamber is configured to supply pressurized fluid to the injection channel.

[0008] The longitudinal lumen of the main body allows, during a surgical intervention involving the section of fibrous tissue, to inject a fluid under overpressure at the front of the hook so as to separate the soft parts and produce a hydro-dissection during the progression of the distal part of the instrument under the fibrous tissue. Furthermore, the elbow of the main body provides a support allowing a controlled rotation to be imparted to the instrument, around the elbow forming an axis of rotation, so as to raise the hook towards the fibrous tissue to hook it, before cutting it by a movement of withdrawal of the instrument.Thus, a surgical treatment instrument according to the invention, the main body of which has both a longitudinal lumen for fluid passage and an elbow with a concavity facing the same side as the hook, makes it possible to carry out with the same instrument, held in one hand, and in a single movement, both the step of advancing the hook under the fibrous tissue until it exceeds it, thanks to hydro-dissection, and the step of hooking and cutting the fibrous tissue, thanks to the rotational guidance provided by the elbow of the main body, from the position of the hook extending beyond the fibrous tissue, which guarantees a controlled engagement of the hook with respect to the fibrous tissue before initiating the withdrawal movement generating the section of the fibrous tissue.

[0009] The or each injection channel is configured to direct a jet of fluid radially outwardly relative to the hook of the distal portion.

[0010] The main body comprises, in the vicinity of its distal end, at least one injection channel in fluid connection with the lumen of the main body, the or each injection channel being configured to direct a fluid jet radially outward relative to the hook of the distal portion. This arrangement ensures that the overpressure fluid jets emitted from the or each injection channel advance the hook, so as to perform hydro-dissection during the hook advancement step. Preferably, in order not to hinder the advancement of the hook under the fibrous tissue, the or each injection channel is configured to direct a fluid jet radially outward relative to the hook without projecting radially outward relative to the distal portion.

[0011] According to a preferred embodiment, the overpressure chamber has a cross-section greater than the cross-section of the lumen of the main body and the cross-section of each injection channel.

[0012] According to one feature, the main body comprises, between the lumen of the main body and the or each injection channel, said overpressure chamber with a cross-section greater than the cross-section of the lumen of the main body and the cross-section of each injection channel. Thanks to the larger cross-section of the overpressure chamber compared to those of the or each injection channel and the lumen of the main body, the overpressure chamber always maintains a high fluid volume, so that it is effective instantly for supplying fluid under pressure to each injection channel and performing hydro-dissection.In particular, the overpressure chamber makes it possible to project pressurized fluid at the or each injection channel without latency between, on the one hand, the action of an operator on a fluid dispensing device, such as a syringe, connected with the lumen of the main body at the proximal end of the instrument and, on the other hand, the ejection of fluid at the or each injection channel. In addition, the higher volume of the overpressure chamber makes it possible to limit fluid leaks at the or each injection channel.

[0013] According to one feature, the or each injection channel is defined in the extension of an upper portion of the lumen of the main body, and of an upper portion of the overpressure chamber when present, so as to direct a jet of fluid above the hook. Here, the term "upper portion" of the lumen of the main body or of the overpressure chamber means a portion which faces the free end of the hook, while a "lower portion" of the lumen of the main body or of the overpressure chamber is a portion which faces the base of the hook.According to an advantageous arrangement, the lumen of the main body, and the overpressure chamber when present, are arranged opposite the opening of the hook, extending radially from the base of the hook to the free end of the hook, while the or each injection channel is arranged opposite the opening of the hook, extending radially from a middle portion of the hook to the free end of the hook. The redirection of the fluid jets above the hook can thus be obtained without the or each injection channel projecting radially outwards relative to the distal portion, which makes it possible not to disturb the progression of the hook as it advances under the fibrous tissue.

[0014] According to one feature, for the or each injection channel, the ratio of the cross-section of the injection channel to the cross-section of the overpressure chamber is less than or equal to 0.5, preferably between 0.45 and 0.5. Such a cross-section ratio between the or each injection channel and the overpressure chamber makes it possible to create an overpressure at each injection channel, such that the jets of fluid propelled from each injection channel are sufficiently powerful to separate the soft parts and allow hydro-dissection during the hook advancement step.

[0015] According to one feature, the ratio of the cross-section of the lumen of the main body to the cross-section of the overpressure chamber is less than or equal to 0.7, preferably between 0.6 and 0.7. Such a cross-section ratio between the lumen of the main body and the overpressure chamber makes it possible to maintain a high volume of fluid in the overpressure chamber, which has the dual advantage of limiting fluid leaks at the or each injection channel and ensuring optimal responsiveness of the instrument to supply pressurized fluid at the or each injection channel, without latency.

[0016] According to one feature, the elbow defines on the concave side an angle of between 90° and 160°, preferably of the order of 120°, between a portion of the main body upstream of the elbow and a portion of the main body downstream of the elbow. Such an angle between the portions upstream and downstream of the elbow is optimal to allow the practitioner to easily and reliably rotate the instrument around the elbow from the position of the hook extending beyond the fibrous tissue, so that the hook hooks the fibrous tissue directly by means of this rotation.

[0017] According to one feature, the cutting blade of the hook comprises an inner blade portion, located inside the hook, and an upstream blade portion, located upstream of the hook, the upstream blade portion being inclined towards the inside of the hook, in particular at an angle of between 5° and 30°, relative to the longitudinal axis of the distal portion. This inclination of the upstream blade portion allows, once the fibrous tissue has been hooked using the hook, to have the upstream blade portion oriented transversely, i.e. at an angle, relative to the tissue and engaged with it. It is thus possible to cut the fibrous tissue not only by means of the inner blade portion, but also by means of the upstream blade portion during the withdrawal movement of the instrument, which is not the case with an upstream blade portion parallel to the longitudinal axis of the distal portion or inclined towards the outside of the hook.This results in improved cutting efficiency of the instrument and reduced effort required by the practitioner to cut the fibrous tissue during the instrument withdrawal movement.

[0018] The inclination of the upstream blade portion is particularly effective in combination with the bend of the main body. Indeed, thanks to the bend of the main body, the instrument according to the invention makes it possible to impose a fixed inclination of the distal portion relative to the fibrous tissue during the withdrawal movement, which makes it possible to guarantee optimal gripping of the fibrous tissue between the inner blade portion and the upstream blade portion.

[0019] The cumulative length of the portion of the main body downstream of the elbow and the distal portion is generally fixed for a given application. For example, in the case of interventions at the wrist or finger, particularly in the treatment of carpal tunnel syndrome or trigger finger, the cumulative length of the portion of the main body downstream of the elbow and the distal portion is typically between 15 mm and 80 mm.

[0020] According to one feature, the length of the portion of the main body upstream of the elbow can be modulated so as to adjust the lever arm, and therefore the force to be applied by the practitioner using the instrument, to cut the fibrous tissue during the withdrawal movement of the instrument. In particular, in the case of interventions at the wrist or finger level, in particular in the context of the treatment of carpal tunnel syndrome or trigger finger, the length of the portion of the main body upstream of the elbow is typically between 10 mm and 100 mm.

[0021] According to one feature, the surgical treatment instrument comprises a tip configured to cooperate with a syringe, so as to put the syringe body in fluid connection with the lumen of the main body at the proximal end of the main body. It is thus possible to inject a fluid under overpressure from the syringe body towards the distal part of the instrument, by acting on the plunger of the syringe, to carry out hydro-dissection at the front of the hook during the step of advancing the hook under the fibrous tissue. Advantageously, the tip of the surgical treatment instrument is a male or female tip, in particular of the Luer Lock type, configured to cooperate with a complementary female or male tip, in particular of the Luer Lock type, of the syringe.

[0022] According to a feature not included within the scope of the claims, the rotation of the surgical treatment instrument around the elbow is actuated by the practitioner by acting on a syringe which is linked to the proximal end of the instrument and forms an actuating handle.Advantageously, the practitioner may then not change his grip on the syringe body between the step of advancing the hook under the fibrous tissue and the step of hooking and cutting the fibrous tissue: in particular, in the step of advancing the hook under the fibrous tissue, the practitioner may hold the syringe body with one hand and act with the same hand on the syringe plunger to perform the hydro-dissection; then, in the step of hooking and cutting the fibrous tissue, the practitioner may maintain his grip on the syringe body with the same hand and pivot the instrument around the elbow to bring the hook into engagement with the fibrous tissue in front of the fibrous tissue before initiating the movement of withdrawing the instrument while still acting on the syringe body.Alternatively, of course, the practitioner may choose to change grip between the step of advancing the hook under the fibrous tissue and the step of hooking and cutting the fibrous tissue, in particular he may hold the syringe body to perform hydro-dissection during the step of advancing the hook, then prefer to hold the main body of the instrument to pivot the instrument around the elbow and activate the movement of withdrawing the instrument during the step of hooking and cutting the fibrous tissue.

[0023] In one embodiment of the invention, the distal portion of the surgical treatment instrument has a sharp, pointed distal end, allowing an entry incision to be made for the introduction of the instrument. An instrument having such a sharp, pointed distal end is used when the intervention site does not involve risks of severing nerves, vessels or other vulnerable structures that are important not to sever, which is the case, for example, for the surgical treatment of trigger finger.

[0024] In another embodiment of the invention, the distal portion of the surgical treatment instrument has a rounded distal end. An instrument having such a rounded distal end is used when the intervention site involves risks of severing nerves, vessels or other vulnerable structures that are important not to be severed, which is the case, for example, for the surgical treatment of carpal tunnel syndrome where the flexor tendons of the fingers and the median nerve running through the carpal tunnel must be preserved.The instrument is then advantageously associated with an insertion cannula having a pointed and sharp distal end, allowing an entry incision to be made for the introduction of the instrument under the skin, the rounded distal end of the instrument then being moved from the insertion cannula to advance under the fibrous tissue to be cut without risk of cutting surrounding vulnerable structures.

[0025] According to one feature, the main body and the distal portion of the surgical treatment instrument are configured to cooperate with an insertion cannula having a pointed and sharp distal end, the insertion cannula comprising a tubular body defining a housing for receiving the distal portion and a support plate for the elbow of the main body.

[0026] According to one feature, the support plate of the insertion cannula has a length, taken along the longitudinal direction of the tubular body, greater than or equal to the length of a fibrous tissue to be sectioned using the surgical treatment instrument. Thus, the support plate provides a support of sufficient length so that the portion of the main body downstream of the elbow can slide systematically on this support plate, without direct contact with the skin, during the step of advancing or withdrawing the hook in the insertion position of the instrument. In addition, this length of the support plate makes it possible to avoid any injury to the skin during the movement of withdrawing the instrument, which could result from a recoil of the support plate if it were too short.For example, in an embodiment specially adapted for the surgical treatment of carpal tunnel syndrome, the length of the support plate of the insertion cannula, taken in the longitudinal direction of the tubular body, is greater than or equal to the length of the tendinous zone of the carpal tunnel. Preferably, a safety margin is provided for the length of the support plate, i.e. the length of the support plate is greater, in particular by about 10% to 50%, than the length of the fibrous tissue to be cut using the surgical treatment instrument.

[0027] According to one feature, the insertion cannula support plate comprises: a middle part for supporting the elbow of the surgical treatment instrument, which is arranged in the extension of the tubular body, and two lateral wings on either side of the middle part, which are capable of being folded towards each other on the side of the tubular body.

[0028] The middle part of the support plate forms a support allowing not only the portion of the main body downstream of the elbow to slide without direct contact with the skin during the step of advancing or withdrawing the hook in the insertion position of the instrument, but also the elbow to take support when pivoting the instrument. The lateral wings of the support plate are intended to be raised so as to surround the main body of the instrument and allow the main body to be grasped to initiate the movement of withdrawing the instrument generating the section of the fibrous tissue.

[0029] According to an unclaimed aspect of the disclosure, which may be considered independently of the features described above, the subject of the invention is a surgical treatment instrument, in particular for tenolysis, tenotomies or neurolysis, comprising a main body and a distal part, where the distal part comprises a curved portion forming a hook and is provided with a cutting blade on the inner side of the hook, the main body comprising a longitudinal lumen for the passage of fluid from a proximal end to a distal end of the main body, the main body of the instrument also comprising, in the vicinity of its distal end, at least one injection channel in fluid connection with the lumen of the main body, the or each injection channel being configured to direct a jet of fluid radially outwards relative to the hook of the distal part,preferably without projecting radially outwards relative to the distal portion. In particular, according to one embodiment, the or each injection channel is defined in the extension of an upper portion of the lumen of the main body, and of a possible overpressure chamber, so as to direct a jet of fluid above the hook.,

[0030] The invention also relates to an assembly according to claim 12 comprising a surgical treatment instrument according to claim 1 and an insertion cannula having a pointed and sharp distal end, the insertion cannula comprising a tubular body delimiting a housing for receiving the distal part of the instrument in the insertion position, and a support plate for the elbow of the main body in the cutting position.

[0031] The invention also relates to an assembly according to claim 13 comprising a surgical treatment instrument according to claim 1 and a syringe whose syringe body is in fluid connection with the lumen of the main body at the proximal end.

[0032] Also disclosed but not claimed is an assembly comprising a surgical treatment instrument and an insertion cannula wherein the bearing plate has a length, in the longitudinal direction of the tubular body, greater than or equal to the length of a fibrous tissue to be sectioned.

[0033] According to another embodiment, the invention also relates to an assembly according to claim 14 comprising a surgical treatment instrument according to any one of claims 1 to 11 and an insertion cannula having a sharp distal end, the insertion cannula comprising a tubular body delimiting a housing for receiving the distal part, and a support plate for the elbow of the main body, in which the support plate comprises a middle part for supporting the elbow in the extension of the tubular body and two lateral wings on either side of the middle part which are capable of being folded towards each other on the side of the tubular body.

[0034] Disclosed but not claimed as such is an insertion cannula for cooperating with a surgical treatment instrument comprising a main body provided with an elbow and a distal portion provided with a cutting hook, the concavity of the elbow facing the same side as the cutting hook, the insertion cannula having a pointed and sharp distal end, the insertion cannula comprising a tubular body defining a housing for receiving the distal portion of the surgical treatment instrument and a support plate for the elbow of the main body of the surgical treatment instrument, wherein the support plate has a length, taken along the longitudinal direction of the tubular body, greater than or equal to the length of a fibrous tissue to be sectioned using the surgical treatment instrument.The support plate thus provides a support of sufficient length so that the portion of the main body downstream of the elbow of the instrument can slide systematically on this support plate, without direct contact with the skin, during the step of advancing or withdrawing the hook in the insertion position of the instrument. In addition, this length of the support plate makes it possible to avoid any injury to the skin during the movement of withdrawing the instrument, which could result from a recoil of the support plate if it were too short.

[0035] According to a characteristic of the unclaimed insertion cannula, the support plate comprises a middle part for supporting the elbow in the extension of the tubular body, and two lateral wings on either side of the middle part which are capable of being folded towards each other on the side of the tubular body.

[0036] Disclosed but not included within the scope of the claims is a method of surgical treatment, including transection of fibrous tissue, such as tenolysis, tenotomy or neurolysis, using a surgical treatment instrument as described above, the method comprising steps wherein: a syringe is assembled with the main body of the instrument, such that the syringe is in fluid connection with the lumen of the main body at the proximal end of the main body; in the insertion position of the instrument, in which the portion of the main body downstream of the bend is parallel to the fibrous tissue to be severed, the distal part of the instrument is inserted through an entry incision and the distal part of the instrument is engaged under the fibrous tissue to be severed until the hook passes it, the engagement of the distal part of the instrument under the fibrous tissue being carried out by hydro-dissection using a fluid contained in the syringe and injected at the front of the distal end of the instrument, by actuating the plunger of the syringe;from the position of the hook extending beyond the fibrous tissue to be severed, the instrument is pivoted around the elbow to a cutting position, in which the portion of the main body downstream of the elbow is transverse to the fibrous tissue to be severed, so that the hook is raised opposite the fibrous tissue to be severed; a withdrawal movement of the instrument is carried out, such that the fibrous tissue to be severed is hooked by the hook and severed by the blade of the distal part; once the fibrous tissue has been severed, the instrument is pivoted around the elbow in the opposite direction to the insertion position and the instrument is extracted through the entry incision. ;

[0037] According to an unclaimed embodiment, when the distal portion of the surgical treatment instrument is inserted using an insertion cannula, the method comprises steps wherein: a syringe is assembled with the main body of the instrument such that the syringe is in fluid connection with the lumen of the main body at the proximal end; an entry incision is made using the sharp distal end of the insertion cannula; the distal portion of the instrument is inserted into the housing of the tubular body of the insertion cannula such that the hook is received in the housing; the distal portion of the instrument is inserted through the entry incision using the insertion cannula, with the instrument in the insertion position;the distal part of the instrument is engaged under the fibrous tissue to be cut by sliding the portion of the main body downstream of the elbow onto the support plate of the insertion cannula until the hook protrudes beyond the fibrous tissue to be cut, the engagement of the distal part of the instrument under the fibrous tissue being carried out by hydro-dissection using a fluid contained in the syringe and injected at the front of the distal end of the instrument, by actuating the plunger of the syringe; from the position of the hook protruding beyond the fibrous tissue to be cut, the instrument is pivoted around the elbow towards the cutting position while resting on the support plate, so that the hook is raised opposite the fibrous tissue to be cut;a withdrawal movement of the instrument is carried out by holding the main body using the support plate of the insertion cannula, such that the fibrous tissue to be cut is hooked by the hook and cut by the blade of the distal part; once the fibrous tissue has been cut, the instrument is pivoted around the elbow in the opposite direction towards the insertion position, taking support on the support plate; the portion of the main body downstream of the elbow is slid onto the support plate of the insertion cannula until the hook is received in the housing of the tubular body of the insertion cannula; the instrument and the insertion cannula are extracted through the entry incision while the hook is received in the housing of the tubular body of the insertion cannula. ;

[0038] The characteristics and advantages of the invention will appear in the following description of two embodiments of an instrument and of an unclaimed method of surgical treatment, given solely by way of example and made with reference to the appended drawings in which: there figure 1 is a section of a surgical treatment instrument according to a first embodiment of the invention; figure 2 is a larger scale view of detail II of the figure 1 ; there figure 3 is a larger scale view of detail III of the figure 1 ; there figure 4 is a cut similar to the figure 1 , the surgical treatment instrument being associated with a syringe; the figure 5 is a section of an insertion cannula adapted to cooperate with the surgical treatment instrument of figures 1 à 4 ; there figure 6 is a top view of the insertion cannula of the figure 5 ; there figure 7 is a section of the distal portion of a surgical treatment instrument according to a second embodiment of the invention.

[0039] On the figure 1 A surgical treatment instrument 1 is shown, of the retro-knife type with a rounded distal end. By way of example, the instrument 1 of this first embodiment is intended for the surgical treatment of carpal tunnel syndrome. The instrument 1 comprises a main body 11, a distal part 12, and a proximal tip 13 configured to cooperate with a syringe. Advantageously, the tip 13 is a male Luer Lock connector comprising a male connector 132 configured to cooperate with a connector 32 complementary to a female Luer Lock connector equipping a syringe 3. The instrument 1 is thus compatible with conventional syringes equipped with female Luer Lock connectors, which are readily available. The distal part 12 of the instrument comprises a curved portion forming a hook 124, and is provided with a cutting blade 125 on the inner side of the hook 124.In addition, the main body 11 comprises an elbow 112 with a concavity facing the same side as the hook 124, which defines on the concave side an angle of the order of 120° between an upstream portion 113 of the main body located upstream of the elbow 112 and a downstream portion 114 of the main body located downstream of the elbow 112.

[0040] The main body 11 of the instrument also comprises a longitudinal lumen 111 for the passage of fluid from a proximal end 110 to a distal end 118 of the main body 11, which continues in the tip 13 by a corresponding lumen 131. As clearly visible in the figure 2 , the main body 11 comprises, in the vicinity of its distal end 118, an injection channel 116 which is in fluid connection with the lumen 111 via an overpressure chamber 115. In this embodiment, each of the lumen 111, the overpressure chamber 115 and the injection channel 116 has a circular section, it being understood that sections of different shapes can be envisaged within the framework of the invention. The overpressure chamber 115 has a diameter D 115 greater than the diameter D 111 of the lumen 111 of the main body and the diameter D 116 of the injection channel 116. Thus having a section greater than those of the lumen 111 of the main body and of the injection channel 116, the overpressure chamber 115 is configured to permanently maintain a high volume of fluid, so that it is effective instantly to supply fluid under pressure at the injection channel 116, without latency time.In addition, the higher volume of the overpressure chamber 115 makes it possible to limit uncontrolled fluid leaks at the injection channel 116.

[0041] The ratio of the diameter D 116 of the injection channel 116 to the diameter D 115 of the overpressure chamber 115 is of the order of 0.45 to 0.5. This makes it possible to create an overpressure at the injection channel 116, so as to generate powerful fluid jets from the injection channel. The ratio of the diameter D 111 of the lumen 111 of the main body to the diameter D 115 of the overpressure chamber is of the order of 0.6 to 0.7. This makes it possible to maintain a high fluid volume in the overpressure chamber 115, with the double advantage of limiting uncontrolled fluid leaks at the injection channel 116 and ensuring optimal responsiveness of the instrument 1 to supply pressurized fluid at the injection channel 116, without latency.In particular, by way of non-limiting example, the overpressure chamber 115 has a diameter D 115 of 2.2 mm; the lumen 111 of the main body 11 has a diameter D 111 of 1.4 mm; the injection channel 116 has a diameter D 116 of 1.06 mm.

[0042] As clearly visible on the figure 2 , the injection channel 116 is defined in the extension of an upper part of the lumen 111 and an upper part of the overpressure chamber 115, so as to direct a jet of fluid above the hook 124. Thus, the redirection of the jets of fluid above the hook 124 is obtained without the channel 116 projecting radially outwards relative to the distal part 12, which makes it possible not to disturb the progression of the hook 124 during its advancement under the fibrous tissue. The longitudinal lumen 111 of the main body makes it possible, during a surgical intervention involving the section of a fibrous tissue, to inject a fluid under overpressure in front of and from above the hook 124 so as to separate the soft parts and produce a hydro-dissection during the progression of the distal part 12 of the instrument under the fibrous tissue.

[0043] Furthermore, the elbow 112 of the main body forms an axis of rotation allowing a controlled rotation of the instrument 1, so as to raise the hook 124 towards the fibrous tissue to hook it, before cutting it by a withdrawal movement of the instrument 1. Thus, the instrument 1 according to the invention, the main body of which has both a longitudinal lumen 111 for fluid passage and an elbow 112 with a concavity facing the same side as the hook 124, allows to carry out with the same instrument, held in one hand, and in a single movement, both the step of advancing the hook 124 under the fibrous tissue thanks to hydro-dissection, and the step of hooking and cutting the fibrous tissue thanks to the rotational guidance provided by the elbow 112.

[0044] The cutting blade 125 comprises an inner blade portion 125a, located inside the bottom of the hook 124, and an upstream blade portion 125b, located upstream of the hook 124. As clearly visible in the figure 3 , the upstream blade portion 125b is inclined towards the inside of the hook at an angle β of the order of 25° relative to the longitudinal axis X 12 of the distal portion 12. This inclination of the upstream blade portion 125b makes it possible, once the fibrous tissue has been hooked using the hook 124, to have the upstream blade portion 125b oriented transversely relative to the fibrous tissue so as to be able to attack the cutting of the fibrous tissue at an angle rather than horizontally. The cutting of the fibrous tissue is thus carried out by means of both the inner blade portion 125a and the upstream blade portion 125b during the withdrawal movement of the instrument 1. The inclination of the upstream blade portion 125b is particularly effective in association with the elbow 112 of the main body 11.Indeed, the elbow 112 makes it possible to impose a fixed inclination of the distal part 12 relative to the fibrous tissue during the withdrawal movement, which makes it possible to guarantee optimal gripping of the fibrous tissue between the inner blade part 125a and the upstream blade part 125b.

[0045] For example, in this first embodiment intended for the surgical treatment of carpal tunnel syndrome, the cumulative length of the downstream portion 114 of the main body and of the distal portion 12 is of the order of 75 mm, which corresponds to the morphology of the carpal tunnel. The length of the upstream portion 113 of the main body 11 can be modulated to adjust the lever arm desired by the surgeon, and therefore the force to be applied to cut the fibrous tissue during the withdrawal movement of the instrument 1. In the context of the treatment of carpal tunnel syndrome, the length of the upstream portion 113 of the main body 11 is typically of the order of 10 mm to 100 mm.

[0046] Optionally, the practitioner may choose not to change his grip on the body 31 of the syringe 3 between the step of advancing the hook 124 under the fibrous tissue and the step of hooking and cutting the fibrous tissue; or the practitioner may choose to change his grip between the step of advancing the hook 124 under the fibrous tissue and the step of hooking and cutting the fibrous tissue, in particular he may hold the body 31 of the syringe to perform the hydro-dissection during the step of advancing the hook 124, then prefer to hold the upstream portion 113 of the main body 11 of the instrument to pivot the instrument around the elbow 112 and activate the movement of withdrawing the instrument during the step of hooking and cutting the fibrous tissue. The selection of one or the other option may depend, in particular, on the length of the upstream portion 113 of the main body 11.

[0047] In this first embodiment, the distal portion 12 of the instrument 1 has a rounded distal end 123. An instrument 1 having such a rounded distal end is used in particular when nerves, vessels, or other vulnerable structures that it is important not to sever are present in the vicinity of the fibrous tissue to be severed, as is the case for example for an intervention at the carpal tunnel. For its insertion under the skin, the instrument 1 is then advantageously associated with an insertion cannula 2 as shown in the figures 5 et 6 , having a pointed and sharp distal end 212 allowing an entry incision to be made for the introduction of the instrument 1. Once inserted under the skin, the rounded distal end 123 of the instrument 1 can be moved from the insertion cannula 2 to advance under the fibrous tissue to be cut without risk of cutting surrounding vulnerable structures. In this first embodiment, by way of example, the instrument 1 and the insertion cannula 2 are made of a biocompatible metal, in particular stainless steel.

[0048] The insertion cannula 2 comprises a tubular body 21 of axis X 2 , which delimits a housing 211 for receiving the distal part 12 of the instrument 1, and a support plate 22, which is intended to receive in support the elbow 112 and the downstream part 114 of the main body 11 of the instrument 1. The distal edge 224 of the support plate 22 forms a limit for insertion of the insertion cannula 2 under the skin.

[0049] In addition, the support plate 22 has a length L, taken along the longitudinal direction of the tubular body 21, greater than or equal to the length of the fibrous tissue to be cut using the instrument 1. Thus, it is ensured that the support plate 22 provides a support of sufficient length so that the downstream portion 114 of the main body 11 can slide systematically without direct contact with the skin during the step of advancing and withdrawing the hook 124 in the insertion position of the instrument 1. In addition, such a length of the support plate 22 makes it possible to avoid injuries to the skin during the withdrawal movement of the instrument 1, which could result from a recoil of the support plate if it were too short.For example, for an insertion cannula 2 suitable for the surgical treatment of carpal tunnel syndrome, the length L of the support plate 22 is equal to the length of the tendinous zone of the carpal tunnel plus a safety margin of 50%, i.e. of the order of 45 mm.

[0050] As visible on the figure 6 , the support plate 22 of the insertion cannula 2 comprises a middle part 222, which is arranged in the extension of the tubular body 21, and two lateral wings 221 on either side of the middle part 222, which are capable of being folded towards each other on the side of the tubular body 21 according to predefined folding lines 223. The middle part 222 forms a support allowing the downstream portion 114 of the main body 11 to slide without direct contact on the skin during the step of advancing and withdrawing the hook 124 in the insertion position of the instrument 1, and the elbow 112 to take support during the pivoting of the instrument 1. The lateral wings 121 of the support plate, when they are raised so as to surround the main body 11 of the instrument 1, allow the gripping, in particular between the thumb and index finger of the practitioner, of the main body 11 on the side of their face 221A opposite the tubular body 21 (lower face on the figure 6 ), in order to initiate the withdrawal movement of instrument 1 generating the section of the fibrous tissue.

[0051] An example of a method of surgical treatment (not included in the scope of the claims) using the instrument 1, associated with the insertion cannula 2, comprises steps as described below. By way of non-limiting example, the method described below can be implemented for the treatment of carpal tunnel syndrome, the fibrous tissue to be cut then being the anterior annular ligament of the carpus.

[0052] First, a syringe 3, the syringe body 31 of which has been previously filled with a hydro-dissection liquid such as a sterile saline solution of the physiological serum type, is assembled with the main body 11 of the instrument 1, such that the syringe body 31 is in fluid connection with the lumen 111 of the main body 11 at the proximal end 110. With reference to the figure 4 , this operation is carried out by connecting the male Luer Lock connector 132 of the tip 13 of the instrument 1 with the complementary female Luer Lock connector 32 of the syringe 3. An entry incision is then made using the distal end 212 of the insertion cannula 2 and then, after having purged the instrument 1 surmounted by the filled syringe, the distal part 12 of the instrument 1 is inserted into the housing 211 of the tubular body 21 of the insertion cannula 2, so that the hook 124 is received in the housing 211. In doing so, the distal part 12 of the instrument 1 is inserted through the entry incision, the instrument 1 being in an insertion position in which the downstream portion 114 of the main body 11 is parallel to the fibrous tissue to be sectioned.

[0053] The downstream portion 114 of the main body 11 is then slid onto the middle portion 222 of the support plate 22 of the insertion cannula 2, so as to engage the distal portion 12 of the instrument 1 under the fibrous tissue to be sectioned. The engagement of the distal portion 12 is achieved by separating the tissues by hydro-dissection, using the hydro-dissection liquid injected at the front of the distal end 123 of the instrument 1 from the injection channel 116, by actuating the piston 33 of the syringe 3. The advancement of the distal portion 12 continues until the hook 124 protrudes beyond the fibrous tissue to be sectioned. Advantageously, the advancement of the hook 124 under the fibrous tissue to be sectioned is controlled using an ultrasound probe that the practitioner holds in one hand, while his other hand actuates both the advancement movement of the instrument 1 and the advancement movement of the piston 33 while holding the syringe 3.

[0054] From the position of the hook 124 protruding beyond the fibrous tissue to be cut, the instrument 1 is pivoted in the direction of the arrow F' of the figure 4 , around the elbow 112 resting on the middle part 222 of the support plate 22, towards a cutting position in which the downstream portion 114 of the main body 11 is transverse to the fibrous tissue to be cut. Thus, the hook 124 is raised opposite the fibrous tissue to be cut. Advantageously, this pivoting of the instrument 1 towards the cutting position can be actuated by acting on the syringe 3, which acts as a handle, in the direction of the arrow F of the figure 4 . Alternatively, the practitioner may prefer to hold the upstream portion 113 of the main body 11 to pivot the instrument 1 around the elbow 112.

[0055] A withdrawal movement of the instrument 1 is then carried out, holding the main body 11 using the lateral wings 221 of the support plate 22 of the insertion cannula 2, folded towards each other on the side of the tubular body 21, so that the fibrous tissue to be cut is hooked by the hook 124 and cut by the blade 125. More precisely, during the withdrawal movement of the instrument 1, the fibrous tissue is engaged between the inner blade portion 125a and the upstream blade portion 125b, which both participate in cutting the fibrous tissue. Once the fibrous tissue has been cut, the instrument 1 is pivoted around the elbow 112 in the opposite direction, that is to say in the direction opposite to the arrow F' of the figure 4 , towards the insertion position by bearing on the middle part 222 of the support plate 22.

[0056] Finally, the downstream portion 114 of the main body 11 is slid onto the middle portion 222 of the support plate 22 of the insertion cannula 2, until the hook 124 is received in the housing 211 of the tubular body 21 of the insertion cannula 2, and the instrument 1 and the insertion cannula 2 are extracted through the entry incision while the hook 124 is received in the housing 211.

[0057] In the second embodiment shown in the figure 7 , elements similar to those of the first embodiment bear identical references. For example, the instrument 1 of this second embodiment is intended for the surgical treatment of trigger finger. The instrument 1 of this second embodiment differs from that of the first embodiment by its distal part 14, which has a pointed and sharp distal end 143 and a differently profiled cutting blade 145, as well as by the respective diameters of the lumen 111, the overpressure chamber 115 and the injection channel 116.

[0058] In a manner similar to the first embodiment, the distal portion 14 comprises a curved portion forming a hook 144, and is provided with a cutting blade 145 on the inner side of the hook 144. The pointed and sharp distal end 143 has the advantage of allowing an entry incision to be made for the introduction of the instrument 1 directly with the instrument 1 itself, without having to resort to an additional insertion cannula. However, an instrument 1 having such a pointed and sharp distal end is only used when the intervention site does not involve risks of severing nerves, vessels or other vulnerable structures, which is the case for example for the surgical treatment of trigger finger. The instrument 1 of the second embodiment also has the same advantages as that of the first embodiment.

[0059] In this second embodiment, by way of example, the instrument 1 is made of a biocompatible metal, in particular stainless steel. As in the first embodiment, the ratio of the diameter D 116 of the injection channel 116 to the diameter D 115 of the overpressure chamber 115 is of the order of 0.45 to 0.5, and the ratio of the diameter D 111 of the lumen 111 of the main body to the diameter D 115 of the overpressure chamber is of the order of 0.6 to 0.7. In particular, by way of non-limiting example, the overpressure chamber 115 has a diameter D 115 of 1.6 mm; the lumen 111 of the main body 11 has a diameter D 111 of 1 mm; the injection channel 116 has a diameter D 116 of 0.8 mm.

[0060] As in the first embodiment, the cutting blade 145 comprises an inner blade portion 145a, located inside in the bottom of the hook 144, and an upstream blade portion 145b, located upstream of the hook 144. It is noted that, in the second embodiment, the upstream blade portion 145b is slightly inclined towards the outside of the hook 144 relative to the longitudinal axis X 14 of the distal portion 14, instead of being inclined towards the inside of the hook as in the first embodiment. Of course, as a variant, the upstream blade portion 145b may be inclined towards the inside of the hook, in particular at an angle of between 5° and 30°, relative to the longitudinal axis of the distal portion 14, to allow, once the fibrous tissue has been hooked using the hook, to have the upstream blade portion 145b oriented transversely relative to the fibrous tissue so that it can attack the cutting of the fibrous tissue at an angle rather than horizontally.

[0061] An exemplary method of surgical treatment (not included in the scope of the claims) using the instrument 1 of the second embodiment, without using an insertion cannula, comprises steps as described below. By way of non-limiting example, the method described below can be implemented for the treatment of trigger finger, the fibrous tissue to be severed then being a pulley surrounding a flexor tendon.

[0062] First, a syringe 3, the syringe body 31 of which has been previously filled with a hydro-dissection liquid such as a sterile saline solution of the physiological serum type, is assembled with the main body 11 of the instrument 1, such that the syringe body 31 is in fluid connection with the lumen 111 of the main body 11 at the proximal end 110.

[0063] After purging the instrument 1 topped with the filled syringe, an entry incision is then made using the pointed and sharp distal end 143 and, in the insertion position of the instrument 1 in which the downstream portion 114 of the main body 111 is parallel to the fibrous tissue to be cut, the distal part 14 of the instrument is inserted through the entry incision.

[0064] The downstream portion 114 of the main body 11 is then advanced so as to engage the distal part 14 of the instrument 1 under the fibrous tissue to be sectioned. The engagement of the distal part 14 is achieved by separating the tissues by hydro-dissection, using the hydro-dissection liquid injected at the front of the distal end 143 of the instrument 1 from the injection channel 116, by actuating the piston 33 of the syringe 3. The advancement of the distal part 14 continues until the hook 144 protrudes beyond the fibrous tissue to be sectioned. Advantageously, the advancement of the hook 144 under the fibrous tissue to be sectioned is controlled using an ultrasound probe that the practitioner holds in one hand, while his other hand actuates both the advancement movement of the instrument 1 and the advancement movement of the piston 33 while holding the syringe 3.

[0065] From the position of the hook 144 protruding beyond the fibrous tissue to be cut, the instrument 1 is pivoted around the elbow 112 in a direction similar to that of the arrow F' of the figure 4 , towards a cutting position in which the downstream portion 114 of the main body 11 is transverse to the fibrous tissue to be cut. Thus, the hook 144 is raised opposite the fibrous tissue to be cut.

[0066] A withdrawal movement of the instrument 1 is then carried out, in particular by holding the syringe body 31 or the main body 11, so that the fibrous tissue to be cut is hooked by the hook 144 and cut by the blade 145. Once the fibrous tissue has been cut, the instrument 1 is pivoted around the elbow 112 in the opposite direction, that is to say in the direction opposite to that of the arrow F' of the figure 4 , towards the insertion position, and the instrument 1 is extracted through the entry incision.

[0067] As is clear from the preceding examples, whatever the embodiment, thanks to the presence of the lumen 111 and the elbow 112 of the main body, a surgical treatment instrument according to the invention makes it possible to carry out with the same instrument, held in one hand, and in a single gesture, both the step of advancing the hook 124, 144 under the fibrous tissue thanks to hydro-dissection, and the step of hooking and cutting the fibrous tissue thanks to the rotational guidance provided by the elbow 112, without requiring prior incision of the skin with a scalpel to introduce the instrument. Very advantageously, a surgical treatment instrument according to the invention is compatible with monitoring using a device, for example an ultrasound probe, held in the other hand than the one that operates the instrument.A surgical treatment instrument according to the invention more generally allows for better controlled interventions to be performed, which limits post-operative pain for the patient and the duration of downtime.

[0068] The invention is not limited to the examples described and shown.

[0069] In particular, in the preceding examples, the invention has been described for the sectioning of fibrous tissues of the wrist or finger, in particular in the context of the treatment of carpal tunnel syndrome or trigger finger. However, a surgical treatment instrument and an insertion cannula according to the invention can be used for the sectioning of any fibrous tissues, in particular fibrous tissues of the hand, shoulder, knee, ankle, foot, the dimensions of the instrument and the insertion cannula then being adapted on a case-by-case basis to correspond to the length and the environment of the fibrous tissue to be sectioned.

[0070] In general, the geometry of a surgical treatment instrument according to the invention may be different from those described previously. In particular: the cumulative length of the portion of the main body downstream of the elbow and of the distal part, if it is substantially fixed for a given application, tends to vary from one application to another; the length of the portion of the main body downstream of the elbow can be modulated so as to adjust the lever arm and therefore the force to be applied by the practitioner to cut the fibrous tissue during the withdrawal movement of the instrument; or the respective diameters of the lumen of the main body, of the overpressure chamber and of the injection channel(s) can be adjusted to optimize the hydro-dissection.A surgical treatment instrument and an insertion cannula according to the invention may also be made of any materials suitable for their function, in particular biocompatible metal and / or polymer. The use of a non-magnetic material, in particular a polymer, is advantageous for enabling MRI (Magnetic Resonance Imaging) monitoring of an intervention involving a surgical treatment instrument and / or an insertion cannula according to the invention.

Claims

1. Surgical treatment instrument (1), in particular for tenolysis, tenotomy or neurolysis, comprising: - a main body (11) comprising a longitudinal lumen (111) for passage of fluid from a proximal end to a distal end (110) to a distal end (118) of the main body (11), and - a distal part (12; 14) including a curved portion forming a hook (124; 144) and being provided with a cutting blade (125; 145) on the inner side of the hook (124; 144), the main body (11) further comprising an elbow (112) presenting a concavity facing the same side as the hook (124; 144), characterised in that the main body has, in the vicinity of its distal end (118): - an over-pressure chamber (115), - an injection channel (116), the injection channel (116) being in fluidic connection with the lumen (111) via the over-pressure chamber (115), the injection channel (116) being configured to direct a fluid stream above the hook (124), the over-pressure chamber (115) being configured to deliver pressurised fluid to the injection channel (116).

2. Surgical treatment instrument according to claim 1, wherein the or each injection channel (116) is configured to direct a stream of fluid radially outwardly from the hook (124; 144) of the distal portion (12; 14).

3. Surgical treatment instrument according to claim 2, wherein the over-pressure chamber (115) has a cross-sectional area (D115) greater than the cross-sectional area (D111) of the lumen (111) of the main body (11) and the cross-sectional area (D116) of each injection channel (116).

4. Surgical treatment instrument according to any one of claims 2 or 3, wherein the or each injection channel (116) is defined as an extension of an upper portion of the lumen (111) of the main body, and an upper portion of the over-pressure chamber (115) where present, so as to direct a stream of fluid above the hook (124; 144).

5. Surgical treatment instrument according to claim 3, wherein the ratio of the cross-sectional area (D111) of the lumen (111) of the main body (11) to the cross-sectional area (D115) of the over-pressure chamber (115) is less than or equal to 0.7, preferably between 0, 6 to 0.7, and wherein for the or each injection channel (116) the ratio of the cross-sectional area (D116) of the injection channel (116) to the cross-sectional area (D115) of the over-pressure chamber (115) is less than or equal to 0.5, preferably between 0.45 and 0.5.

6. Surgical treatment instrument according to any one of the preceding claims, wherein the elbow (112) defines on the concave side an angle (α) of between 90° and 160°, preferably of the order of 120°, between a portion (113) of the main body (11) upstream of the elbow (112) and a portion (114) of the main body (11) downstream of the elbow (112).

7. Surgical treatment instrument according to any one of the preceding claims, wherein the cutting blade (125; 145) of the hook (124; 144) comprises an inner blade portion (125a; 145a) inside the hook (124; 144) and an upstream blade portion (125b ; 145b) upstream of the hook (124; 144), the upstream blade portion (125b; 145b) being inclined towards the inside of the hook, in particular at an angle (β) of between 5° and 30°, relative to the longitudinal axis (X12; X14) of the distal portion (12; 14).

8. Surgical treatment instrument according to any one of the preceding claims, comprising a tip (13) configured to cooperate with a syringe (3) so as to bring the syringe body (31) into fluidic connection with the lumen (111) of the main body (11) at the proximal end (110).

9. The surgical treatment instrument according to any of claims 1 to 8, wherein the distal portion (14) has a sharp distal end (143).

10. Surgical treatment instrument according to any one of claims 1 to 8, wherein the distal portion (12) has a rounded distal end (123).

11. Surgical treatment instrument according to claim 10, wherein the main body (11) and the distal portion (12) are configured to cooperate with an insertion cannula (2) having a sharp distal end (212), the insertion cannula (2) comprising a tubular body (21) delimiting a housing (211) for receiving the distal portion (12) and a support plate (22) for the elbow (112) of the main body (11).

12. Assembly comprising a surgical treatment instrument (1) according to any one of claims 1 to 11 and an insertion cannula (2) having a sharp distal end (212), the insertion cannula (2) comprising a tubular body (21) delimiting a housing (211) for receiving the distal part (12), and a plate (22) for supporting the elbow (112) of the main body (11).

13. Assembly comprising a surgical treatment instrument (1) according to any of claims 1 to 11 and a syringe (3) in fluidic connection with the lumen (111) of the main body (11) at the proximal end (110).

14. Assembly according to claim 12, wherein the support plate (22) comprises a median part (222) for supporting the elbow (112) in the extension of the tubular body (21) and two lateral wings (221) on either side of the median part (222), which are capable of being folded towards each other on the side of the tubular body (21).