Minimally invasive dilator and ligament cutting medical instrument

Abstract

The utility model relates to the technical field of medical instruments, in particular to a minimally invasive dilator and a ligament cutting medical instrument. The minimally invasive dilator comprises an upper rod body and a lower rod body which respectively extend along a straight line, two extending ends of the upper rod body are respectively a first end and a second end, and two extending ends of the lower rod body are respectively a third end and a fourth end; wherein the first end and the third end can form a revolute pair or can be separated from each other, and in the process that the first end and the third end form the revolute pair and rotate relatively, the second end and the fourth end get close to each other or get away from each other. The technical problem that in the prior art, in the process that a cutter stretches into a window in the wrist and cuts the transverse ligament of the wrist, the phenomenon that the cutter cuts the skin of the palm in the direction pointing to the skin of the palm from the transverse ligament of the wrist is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, and particularly relates to a minimally invasive dilator and a medical device for cutting ligaments. Background Art

[0002] Carpal tunnel syndrome is one of the most common nerve entrapment syndromes. The main symptoms are numbness and weakness in the hand and atrophy of the thenar muscles, which are common in the thumb, index finger, middle finger and the radial half of the ring finger in the distribution area of the median nerve. The main reason is that the transverse carpal ligament compresses the median nerve. Clinically, it is usually treated by incising the transverse carpal ligament to eliminate the compression of the median nerve by the transverse carpal ligament, thereby alleviating the symptoms and preventing the symptoms from further aggravating.

[0003] Clinically, the traditional large incision method, that is, the classic large "S" incision from the wrist palm to the distal forearm proposed by Phalen, has a definite curative effect. However, due to the long recovery period of hand function after surgery, the grip strength and pinch strength of the hand are significantly reduced, and complications such as "pillar pain" and scar discomfort and lack of beauty can reach 6% - 18%. Now, most tend to small incision minimally invasive treatment. However, small incision treatment has the risk of iatrogenic injury to the deep median nerve, tendon, superficial skin soft tissue and distal median nerve branches and superficial palmar arch. Endoscopic treatment is a feasible method to avoid these risks, but it requires arthroscopic equipment and small lenses, and the technical requirements are very high. Most grass-roots hospitals are unable to carry out it.

[0004] As Figure 1 shown, it is a wrist tunnel surgical instrument in the prior art with the application number TW090209297, which includes a support rod and a cutter. The support rod is provided with a strip-shaped groove, and the cutter can be movably inserted into the strip-shaped groove. As Figure 2 shown, the structure of the palm from the palm heart to the back of the hand is successively: palm skin, transverse carpal ligament, median nerve, tendon and bone, and back of the hand skin.

[0005] During use, a window is opened at the wrist, the window is opened wide, the support rod is inserted from the window under the transverse carpal ligament, then the cutter is set in the strip-shaped groove, flat against the groove wall of the strip-shaped groove, and the cutter is smoothly pushed. The cutting edge of the cutter is on the same horizontal plane as the transverse carpal ligament, so that the cutter cuts the transverse carpal ligament.

[0006] When using the wrist tunnel surgical instrument of the prior art to cut the transverse carpal ligament, the following problems are likely to occur. During the process of smoothly pushing the cutter along the strip-shaped groove, in the direction from the transverse carpal ligament to the palm skin, the cutter is likely to cut the palm skin, thereby increasing the palm trauma of the patient.

[0007] Therefore, the technical problem existing in the prior art is how to avoid the cutting tool from cutting through the palm skin in the direction from the transverse carpal ligament to the palm skin during the process of the cutting tool extending into the wrist through the window and cutting the transverse carpal ligament. Summary of the Invention

[0008] In view of the technical problem existing in the prior art: how to avoid the cutting tool from cutting through the palm skin in the direction from the transverse carpal ligament to the palm skin during the process of the cutting tool extending into the wrist through the window and cutting the transverse carpal ligament. The present utility model provides a minimally invasive dilator and a medical instrument for cutting ligaments.

[0009] The present utility model is realized through the following technical solutions:

[0010] A minimally invasive dilator, which includes an upper rod body and a lower rod body that extend along a straight line respectively. The two ends of the upper rod body in the extending direction are respectively a first end and a second end, and the two ends of the lower rod body in the extending direction are respectively a third end and a fourth end;

[0011] Wherein, the first end and the third end can form a rotating pair or be separated from each other. During the process of the first end and the third end forming a rotating pair and rotating relative to each other, the second end and the fourth end approach or move away from each other.

[0012] Furthermore,

[0013] It further includes a sliding arm, the sliding arm is connected to the lower rod body, the sliding arm is provided with an arc-shaped groove, and the arc-shaped groove is curved with the intersection of the first end and the third end as the center of the circle;

[0014] It further includes a guiding body, the guiding body is connected to the upper rod body, the guiding body is movably and inseparably arranged in the arc-shaped groove, and forms an arc-shaped sliding pair with the arc-shaped groove.

[0015] Furthermore,

[0016] It further includes a fixing body, the fixing body is connected to the guiding body, and the second end is locked or released from the sliding arm through the fixing body.

[0017] Furthermore,

[0018] The lower rod body is provided with a guiding groove, the extending direction of the guiding groove is the same as the extending direction of the lower rod body, the guiding groove forms a first long opening on the circumferential outer surface of the lower rod body, and intersects with the fourth end of the lower rod body to form a first opening.

[0019] Furthermore,

[0020] On the circumferential outer wall of the side of the upper rod body facing the lower rod body, there is an avoidance groove, the extending direction of the avoidance groove is the same as the extending direction of the upper rod body, along the extending direction of the upper rod body, the avoidance groove is opened at a preset position, and the length of the avoidance groove is configured as a preset length.

[0021] Further, it further includes a protective body, which is connected to the third end along the extending direction of the lower rod body; the protective body has an arc-shaped outer surface.

[0022] Further, the arc-shaped outer surface is: a first contact surface provided on the outer surface of the side of the protective body facing away from the third end, and in the direction from the fourth end to the third end, the first contact surface protrudes outward.

[0023] Further, the arc-shaped outer surface is: a second contact surface provided on the side of the protective body facing away from the third end, and the second contact surface is recessed toward the direction where the fourth end is located.

[0024] A medical instrument for cutting ligaments is also proposed, which includes the above-mentioned dilator.

[0025] Further, it further includes a cutter body, the cutter body extends along a straight line, and along the extending direction of the cutter body, a spike portion is provided at one end of the cutter body;

[0026] The cutter body can be movably inserted into the guide groove from the first opening; a contact portion is provided on the outer surface of the cutter body, and the contact portion is in sliding contact with the guide groove.

[0027] Compared with the prior art, the advantages of the present utility model are as follows:

[0028] 1. The present utility model proposes a minimally invasive dilator; first, for the minimally invasive dilator of the present utility model, before the cutter is inserted, along the direction from the transverse carpal ligament to the palm skin, the upper rod body is arranged above the transverse carpal ligament and abuts against the palm skin, and the lower rod body is arranged below the transverse carpal ligament. When the first end and the third end rotate relative to each other, the second end and the fourth end move away from each other, and the upper rod body and the lower rod body make the palm skin and the transverse carpal ligament move away from each other, that is, the distance between the palm skin and the transverse carpal ligament is enlarged. Further, after the cutter is inserted into the first window and during the process of cutting the transverse carpal ligament, the cutter will not contact the palm skin, nor will it cut the palm skin in the direction from the transverse carpal ligament to the palm skin; second, in addition to the function of enlarging the distance between the palm skin and the transverse carpal ligament, the upper rod body of the present utility model also plays an effective role in protecting the palm skin. After the cutter is inserted into the first window and during the process of cutting the transverse carpal ligament, the cutter and the palm skin are blocked by the upper rod body. If the cutter accidentally lifts upward in the direction from the transverse carpal ligament to the palm skin, it will touch the upper rod body instead of the palm skin, and further avoids the situation that the cutter cuts the palm skin in the direction from the transverse carpal ligament to the palm skin.

[0029] In summary, the present utility model solves the technical problem existing in the prior art: how to avoid the cutter cutting the palm skin in the direction from the transverse carpal ligament to the palm skin during the process of the cutter being inserted into the window at the wrist and cutting the transverse carpal ligament. Description of the Drawings

[0030] Figure 1 Schematic structural diagram of the existing wrist tunnel surgical instrument in the background art;

[0031] Figure 2 Schematic structural diagram of the transverse carpal ligament in the background art;

[0032] Figure 3 Schematic structural diagram of the minimally invasive dilator in Embodiment 1;

[0033] Figure 4 For Figure 3 Schematic structural diagram from another perspective;

[0034] Figure 5 Schematic structural diagram of the upper rod body in Embodiment 1;

[0035] Figure 6 Schematic diagram of the position where the first window is opened;

[0036] Figure 7 Schematic diagram of the use of the minimally invasive dilator in Embodiment 1;

[0037] Figure 8 Schematic structural diagram of the protective body in Embodiment 1;

[0038] Figure 9 Another schematic structural diagram of the protective body in Embodiment 1;

[0039] Figure 10 One of the schematic structural diagrams of the knife body in Embodiment 2;

[0040] Figure 11 Another schematic structural diagram of the knife body in Embodiment 2;

[0041] Figure 12 Schematic structural diagram of the medical instrument for cutting the ligament in Embodiment 2.

[0042] Markings in the figure: upper rod body (1), first end (101), second end (102), relief groove (103);

[0043] Lower rod body (2), third end (201), fourth end (202), guide groove (203);

[0044] Sliding arm (3), arc groove (4), guide body (5), fixed body (6), protective body (7);

[0045] Knife body (8), friction part (801). Detailed implementation manners

[0046] The technical solution of the utility model will be further described in detail in a non-limiting manner in conjunction with the preferred embodiments and their accompanying drawings. In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present utility model and should not be construed as limiting the present utility model.

[0047] Embodiment 1

[0048] As Figures 3 to 4 shown, this embodiment is a preferred embodiment of the present utility model. This embodiment provides a minimally invasive dilator, which includes an upper rod body 1 and a lower rod body 2 that extend along a straight line respectively. The two ends of the upper rod body 1 that extend are a first end 101 and a second end 102 respectively, and the two ends of the lower rod body 2 that extend are a third end 201 and a fourth end 202 respectively;

[0049] Among them, the first end 101 and the third end 201 can form a rotating pair or separate from each other. During the process of the first end 101 and the third end 201 forming a rotating pair and rotating relative to each other, the second end 102 and the fourth end 202 approach or move away from each other.

[0050] Referring to Figures 3 to 5 , both the upper rod body 1 and the lower rod body 2 are rod-shaped structures, and the first end 101 and the third end 201 can form a rotating pair. The rotating pair in this embodiment is: a sphere is provided at the first end 101 of the upper rod body 1, and a spherical socket is provided at the third end 201 of the lower rod body 2. The sphere can be inserted into the spherical socket along the axial direction of the lower rod body 2 or in a direction forming an acute angle with the axial direction of the lower rod body 2, and is in rotatable contact with the inner wall of the spherical socket; preferably, the wall body forming the spherical socket can limit the sphere in the radial direction of the lower rod body 2 to prevent the sphere from separating from the spherical socket along the radial direction of the lower rod body 2 during the process of the sphere being inserted into the spherical socket and rotating.

[0051] A spherical body is provided at the first end 101 of the upper rod body 1, and a socket is provided at the third end 201 of the lower rod body 2. The spherical body can be inserted into the socket and matched with the socket to form a rotating pair, so as to prevent the first end 101 from protruding from the third end 201 and accidentally injuring the patient's tissue during the rotation of the upper rod body 1 relative to the lower rod body 2.

[0052] In this embodiment, the upper rod body 1 and the lower rod body 2 form a revolving pair through the first end 101 and the third end 201, and the second end 102 and the fourth end 202 can be close to each other or away from each other. When the second end 102 and the fourth end 202 are close to each other, the upper rod body 1 and the lower rod body 2 change from an open state to a closed state, and the second end 102 and the fourth end 202 are away from each other, that is, the upper rod body 1 and the lower rod body 2 change from a closed state to an open state.

[0053] Combination Figure 6 , Figure 7 When using the minimally invasive dilator of this embodiment: first, a first window is opened at the patient's wrist, and the first window is set on the side away from the back of the hand. The lower rod body 2 enters from the first window and passes through from below the transverse carpal ligament, and the lower rod body 2 is pushed to the specified position; then, the first end 101 of the upper rod body 1 enters from the first window and passes from above the transverse carpal ligament, and the upper rod body 1 is pushed until the first end 101 of the upper rod body 1 and the third end 201 of the lower rod body 2 contact each other and form a revolute pair, that is, the ball head mentioned above is inserted into the ball socket, and at this time, the second end 102 and the fourth end 202 are both outside the patient's body; after that, the medical staff The staff member holds the lower rod body 2 to keep it still and lifts the second end 102 of the upper rod body 1, so that the first end 101 and the third end 201 rotate relatively, and the second end 102 and the fourth end 202 move away from each other; in this process, the transverse carpal ligament is located between the upper rod body 1 and the lower rod body 2, and the lower rod body 2 presses against the median nerve, and the upper rod body 1 stretches the palm skin upward, and then through the minimally invasive dilator of this embodiment, the distance between the palm skin and the transverse carpal ligament is expanded in the direction of the transverse carpal ligament pointing to the palm skin; thereafter, the tool is inserted from the first window between the upper rod body 1 and the lower rod body 2, and the tool is pushed to cut the transverse carpal ligament.

[0054] The first window is the wrist window in the prior art.

[0055] From the background technology, it can be known that the technical problem existing in the prior art is how to avoid the knife from cutting the palm skin in the direction from the transverse carpal ligament to the palm skin when the knife is inserted from the window at the wrist and cuts the transverse carpal ligament.

[0056] Based on this, this embodiment proposes a minimally invasive dilator. First, for the minimally invasive dilator of this embodiment, the upper rod body 1 and the lower rod body 2 both extend into the palm from the first window. Before the tool extends in, along the direction from the transverse carpal ligament to the palm skin, the upper rod body 1 is arranged above the transverse carpal ligament and abuts against the palm skin, and the lower rod body 2 is arranged below the transverse carpal ligament. When the first end 101 and the third end 201 rotate relative to each other, the second end 102 and the fourth end 202 move away from each other. The upper rod body 1 and the lower rod body 2 cause the palm skin and the transverse carpal ligament to move away from each other, that is, the distance between the palm skin and the transverse carpal ligament is enlarged. Furthermore, after the tool extends into the first window and during the process of cutting the transverse carpal ligament, the tool will not contact the palm skin, nor will it cut the palm skin in the direction from the transverse carpal ligament to the palm skin. Second, the upper rod body 1 of this embodiment not only plays the role of enlarging the distance between the palm skin and the transverse carpal ligament, but also plays the role of effectively protecting the palm skin. After the tool extends into the first window and during the process of cutting the transverse carpal ligament, the tool and the palm skin are blocked by the upper rod body 1. If the tool accidentally lifts upward in the direction from the transverse carpal ligament to the palm skin, it will touch the upper rod body 1 instead of the palm skin, further avoiding the situation where the tool cuts the palm skin in the direction from the transverse carpal ligament to the palm skin.

[0057] In summary, this embodiment solves the technical problem existing in the prior art: how to avoid the tool cutting the palm skin in the direction from the transverse carpal ligament to the palm skin during the process of the tool extending from the window at the wrist and cutting the transverse carpal ligament.

[0058] Furthermore, in this embodiment, first, the upper rod body causes the palm skin and the transverse carpal ligament to move away from each other, that is, the distance between the palm skin and the transverse carpal ligament is enlarged. Furthermore, after the tool extends into the first window and during the process of cutting the transverse carpal ligament, the tool will not contact the palm skin, nor will it cut the palm skin in the direction from the transverse carpal ligament to the palm skin, realizing minimally invasive dilation of the superficial layer of the transverse carpal ligament. Second, the lower rod body causes the transverse carpal ligament and the deep median nerve and tendons to move away from each other, avoiding damaging the important deep median nerve and tendons during the cutting process.

[0059] As Figure 3 、 Figure 7 shown, furthermore, this embodiment also includes the following technical solution: the minimally invasive dilator further includes a sliding arm 3. The sliding arm 3 is connected to the lower rod body 2. The sliding arm 3 is provided with an arc-shaped groove 4, and the arc-shaped groove 4 is curved with the intersection of the first end 101 and the third end 201 as the center of the circle. It further includes a guiding body 5. The guiding body 5 is connected to the upper rod body 1. The guiding body 5 is movably and inseparably arranged in the arc-shaped groove 4 and forms an arc-shaped sliding pair with the arc-shaped groove 4.

[0060] The sliding arm 3 and the lower rod body 2 can be detachably connected by screws or bolts. On the one hand, it is beneficial to simplify the processing technology of the two components of the sliding arm 3 and the lower rod body 2. On the other hand, when not in use, the sliding arm 3 can be removed from the lower rod body 2 to save storage space.

[0061] The arc-shaped groove 4 can be a major arc shape or a minor arc shape, and is a minor arc shape in this embodiment; the shape and structure of the guide body 5 are various, such as a pin body provided on the outer surface of the upper rod body 1; in this embodiment, the upper rod body 1 has a first threaded hole penetrating through the upper rod body 1 in the radial direction. Through the first threaded hole, a first screw is detachably connected to the outer surface of the upper rod body 1, and the rod portion of the first screw penetrates through the arc-shaped groove 4, and the guide body 5 is the rod portion of the first screw; preferably, along the extending direction of the upper rod body 1, the connection position of the guide body 5 and the upper rod body 1 is located between the first end 101 and the second end 102.

[0062] In this embodiment, between the upper rod body 1 and the sliding arm 3, through the arc-shaped sliding pair composed of the guide body 5 and the arc-shaped groove 4, the sliding arm 3 plays a guiding role in the movement path of the second end 102 of the upper rod body 1.

[0063] As Figure 3 shown, further, this embodiment further includes the following technical solution. The minimally invasive dilator further includes a fixing body 6. The fixing body 6 is connected to the guide body 5, and the second end 102 is locked or released from the sliding arm 3 through the fixing body 6.

[0064] Specifically, the fixing body 6 is the head of the first screw. The head of the first screw is restricted outside the arc-shaped groove 4. The first screw is screwed into the first screw hole, so that the head of the first screw is in close contact with one side surface of the sliding arm 3. Further, the second end 102 is locked with the sliding arm 3. At this time, the second end 102 cannot move relative to the sliding arm 3; the first screw is screwed out of the first screw hole, so that there is a gap between the head of the first screw and any surface of the sliding arm 3, then the second end 102 and the sliding arm 3 are released from each other. At this time, the second end 102 can move relative to the sliding arm 3.

[0065] In this embodiment, through the fixing body 6, the second end 102 and the sliding arm 3 are locked or released from each other; through the fixing body 6, medical staff do not need to always apply a force to the second end 102, that is, the second end 102 can be made to maintain the opening effect on the palm skin, achieving the purpose of saving manpower.

[0066] As Figure 4 shown, further, in this embodiment, it further includes the following technical solution. The lower rod body 2 is provided with a guide groove 203. The extending direction of the guide groove 203 is the same as the extending direction of the lower rod body 2. The guide groove 203 forms a first long strip opening on the circumferential outer surface of the lower rod body 2, and intersects with the fourth end 202 of the lower rod body 2 to form a first opening.

[0067] In this embodiment, the guiding groove 203 is a groove structure extending along a straight line, and its extending direction is the same as that of the lower rod body 2. When the tool extends in, it can extend into the guiding groove 203 from the first opening and slide along the groove wall of the guiding groove 203; along the direction from the transverse carpal ligament to the palm skin, the width of the cutting edge of the tool should be such that at least a part extends out of the first long opening, so as to cut the transverse carpal ligament. In this embodiment, by providing the guiding groove 203, the tool is guided accordingly.

[0068] Furthermore, in this embodiment, the following technical solution is also included. An avoidance groove 103 is provided on the circumferential outer wall of the upper rod body 1 facing the lower rod body 2. The avoidance groove 103 is in the same extending direction as the upper rod body 1. Along the extending direction of the upper rod body 1, the avoidance groove 103 is opened at a preset position, and the length of the avoidance groove 103 is configured as a preset length.

[0069] The preset position and the preset length can be set according to specific situations respectively. The settings of the preset position and the preset length should meet the requirement that during the movement of the tool to cut the transverse carpal ligament, the upper rod body 1 plays an avoidance role for the movement path of the tool through the avoidance groove 103, avoiding the situation that the circumferential outer wall of the upper rod body 1 facing the lower rod body 2 blocks the movement path of the tool, resulting in the tool being unable to completely cut the transverse carpal ligament.

[0070] As Figure 2 shown, there is an ellipsoidal nerve branch at the center of the palm. If the third end 201 of the lower rod body 2 is spiked, when the third end 201 of the lower rod body 2 contacts the ellipsoidal nerve branch, it will stimulate the ellipsoidal nerve branch and cause discomfort to the patient; therefore, how to avoid the outer surface of the third end 201 of the lower rod body 2 from stimulating the ellipsoidal nerve branch is a technical problem to be solved, and this technical problem is achieved through the following technical solution.

[0071] Furthermore, in this embodiment, the following technical solution is also included. The minimally invasive dilator further includes a protection body 7. Along the extending direction of the lower rod body 2, the protection body 7 is connected to the third end 201, and the protection body 7 has an arc-shaped outer surface.

[0072] In this embodiment, the protection body 7 has an arc-shaped outer surface. When the lower rod body 2 contacts the ellipsoidal nerve branch through the protection body 7, a sliding contact can be formed between the arc-shaped outer surface and the outer surface of the ellipsoidal nerve branch, thereby avoiding stimulating the ellipsoidal nerve branch.

[0073] As Figures 8 to 9 shown, for example, the arc-shaped outer surface is: a first contact surface provided on the outer surface of the protection body 7 facing away from the third end 201, and the first contact surface protrudes outward in the direction from the fourth end 202 to the third end 201.

[0074] For another example, the arc-shaped outer surface is the second contact surface provided on the side of the protective body 7 facing away from the third end 201, and the second contact surface is recessed in the direction of the fourth end 202. In this case, the protective body 7 is in a bowl shape, and the bowl-shaped protective body 7 can be buckled on the ellipsoidal nerve branch through the second contact surface. On the one hand, the second contact surface plays a role in protecting the ellipsoidal nerve branch and can avoid irritating the ellipsoidal nerve branch. On the other hand, the edge of the second contact surface and the outer surface of the ellipsoidal nerve branch can form a limiting relationship along the radial direction of the lower rod body 2, so as to prevent the protective body 7 from moving relative to the ellipsoidal nerve branch along the radial direction of the lower rod body 2.

[0075] At the palm corresponding to the ellipsoidal nerve branch, there is no need to set a trauma window, and the doctor can judge the relative position of the protective body 7 and the ellipsoidal nerve branch according to the feel of touching the palm.

[0076] Embodiment 2

[0077] As Figures 10 to 12 shown, this embodiment provides a medical instrument for cutting ligaments, which includes the dilator mentioned in Embodiment 1.

[0078] Furthermore, the medical instrument for cutting ligaments in this embodiment further includes a knife body 8. The knife body 8 extends in a straight line, and along the extension direction of the knife body 8, a spike portion is provided at one end of the knife body 8; the knife body 8 can movably extend into the guide groove 203 from the first opening; a contact portion is provided on the outer surface of the knife body 8, and the contact portion is in sliding contact with the guide groove 203.

[0079] The knife body 8 has a front end and a rear end. The spike portion is provided at the front end of the knife body 8, and a handle is provided at the rear end of the knife body for a medical staff to hold.

[0080] A friction portion 801 is provided at the handle for increasing the friction between the palm of the medical staff and the handle. Among them, the friction portion 801 is a protrusion or a groove.

[0081] The spike portion is used to cut the transverse carpal ligament. The spike portion has several structures. For example, the spike portion is provided at the front end of the knife body and protrudes outward in the direction from the rear end to the front end, that is Figure 10 shown. Or, for another example, the spike portion is provided at the front end of the knife body, and the spike portion is in the shape of an inverted hook, as Figure 11 shown.

[0082] Preferably, the same medical instrument for cutting ligaments can be equipped with knife bodies 8 of various model specifications. For example, in this embodiment, the medical instrument for cutting ligaments has a first knife body and a second knife body. Among them, the spike portion of the first knife body is provided at the front end of the knife body and protrudes outward in the direction from the rear end to the front end; the spike portion of the second knife body is provided at the front end of the knife body, and the spike portion is in the shape of an inverted hook.

[0083] During the operation, if the first knife body cannot completely cut off the transverse carpal ligament when cutting along the direction from the rear end to the front end, then the second knife body is used to hook and cut off the transverse carpal ligament in the direction from the front end to the rear end.

[0084] When using the medical instrument for cutting ligaments, a first transverse window is opened at the transverse carpal crease, the window is opened, the upper rod body 1 and the lower rod body 2 are inserted into the window, and minimally invasive dilation is performed. The upper rod body 1 and the lower rod body 2 are respectively located in the deep and shallow layers of the transverse carpal ligament. After passing through the transverse carpal ligament, the sphere and the ball socket are aligned on the distal side of the transverse carpal ligament. Then, the knife body 8 (the first knife body or the second knife body) is arranged in the guide groove 203, flat against the groove wall of the guide groove 203, and the knife body 8 is smoothly pushed. The cutting edge of the knife body is on the same horizontal plane as the transverse carpal ligament, so that the knife body can completely cut the transverse carpal ligament and can protect the deep median nerve and tendon, the superficial skin soft tissue, the distal median nerve branch, and the superficial palmar arch in a three-dimensional and all-round manner. The operation process takes about 15 minutes. Therefore, using this instrument can safely, quickly, and effectively complete the median nerve release surgery, and is more suitable for being carried out in the vast majority of primary hospitals.

[0085] The above embodiments only represent several implementation manners of the present utility model, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several deformations and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the patent of the present utility model shall be subject to the appended claims.

Claims

1. A minimally invasive dilator, characterized in that: It comprises an upper rod body (1) and a lower rod body (2) respectively extending in a straight line, wherein two ends of the upper rod body (1) are respectively a first end (101) and a second end (102), and two ends of the lower rod body (2) are respectively a third end (201) and a fourth end (202); The first end (101) and the third end (201) can form a rotating pair or be separated from each other. When the first end (101) and the third end (201) form a rotating pair and rotate relative to each other, the second end (102) and the fourth end (202) approach each other or move away from each other.

2. The minimally invasive dilator according to claim 1, characterized in that: It also includes a sliding arm (3), the sliding arm (3) is connected to the lower rod body (2), the sliding arm (3) is provided with an arc groove (4), and the arc groove (4) is curved with the intersection of the first end (101) and the third end (201) as the center of the circle; The guide body (5) is also included. The guide body (5) is connected to the upper rod body (1). The guide body (5) is movably and inseparablely arranged in the arc groove (4) and forms an arc sliding pair with the arc groove (4).

3. The minimally invasive dilator according to claim 2, characterized in that: It also includes a fixing body (6), which is connected to the guide body (5), and the second end (102) is locked or released with the sliding arm (3) through the fixing body (6).

4. The minimally invasive dilator according to claim 3, characterized in that: The lower rod body (2) is provided with a guide groove (203), the extension direction of the guide groove (203) is consistent with the extension direction of the lower rod body (2), the guide groove (203) forms a first long strip opening on the circumferential outer surface of the lower rod body (2), and intersects with the fourth end (202) of the lower rod body (2) to form a first opening.

5. The minimally invasive dilator according to claim 4, characterized in that: An avoidance groove (103) is provided on a circumferential outer wall of one side of the upper rod body (1) facing the lower rod body (2); the avoidance groove (103) is consistent with the extension direction of the upper rod body (1); along the extension direction of the upper rod body (1), the avoidance groove (103) is opened at a preset position; and the length of the avoidance groove (103) is configured to be a preset length.

6. The minimally invasive dilator according to claim 5, characterized in that: It also comprises a protection body (7), which is connected to the third end (201) along the extension direction of the lower rod body (2); the protection body (7) has an arc-shaped outer surface.

7. The minimally invasive dilator according to claim 6, characterized in that: The arc-shaped outer surface is: a first contact surface provided on the outer surface of the protective body (7) on a side away from the third end (201), pointing from the fourth end (202) to the direction of the third end (201), and the first contact surface protrudes outward.

8. The minimally invasive dilator according to claim 6, characterized in that: The arc-shaped outer surface is: a second contact surface provided on the side of the protection body (7) away from the third end (201), and the second contact surface is concave in the direction of the fourth end (202).

9. A medical device for cutting ligaments, characterized in that: A dilator comprising any one of claims 4-8.

10. The medical instrument for cutting ligaments according to claim 9, characterized in that: It also includes a blade body (8), the blade body (8) extends in a straight line, and a spike portion is provided at one end of the blade body (8) along the extension direction of the blade body (8); The knife body (8) can be movably extended from the first opening into the guide groove (203); a contact portion is provided on the outer surface of the knife body (8), and the contact portion is in sliding contact with the guide groove (203).

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