Distraction device and distraction equipment suitable for high tibial osteotomy

Abstract

The invention provides a distraction device and distraction equipment suitable for wedge high tibial osteotomy, and relates to the technical field of medical surgical instruments, the distraction device comprises a support, a first knife group, a second knife group and a first actuating part; the first cutter set is arranged on the support and protrudes out of the support in the first direction. The second cutter set is arranged on the support and protrudes out of the support in the second direction forming a first included angle with the first direction. And the first actuating part is configured to drive the bracket to rotate around the fixed shaft of the rotating shaft, so that the first knife group or the second knife group faces and extends into the bone seam. Wherein the thickness of the first knife group is configured to be smaller than that of the second knife group.

Description

Technical Field

[0001] This disclosure relates to the field of medical surgical instruments, and in particular to a retractor and retractor device suitable for high tibial osteotomy. Background Technology

[0002] High tibial osteotomy is a surgical procedure that involves cutting the bone and readjusting its position to restore the normal anatomical structure and force alignment of the skeleton. In high tibial osteotomy, a medical oscillating saw is often used to create a wedge-shaped opening (i.e., a suture) and a bone hinge. Then, a thin, hard bone chisel is used to slowly adjust and open the suture to correct the force alignment, avoiding iatrogenic fractures caused by excessive speed. Finally, after the chisel is removed, a bone retractor is inserted into the edge of the suture and slowly opened to the desired angle. This angle is then fixed with a locking plate and bolts. However, the quality of this chisel-based method relies solely on the surgeon's experience and intuition, making it impossible to directly and precisely control the suture width. Furthermore, if the hinge breaks, postoperative recovery will be extremely difficult, and the surgical outcome will be significantly reduced. Additionally, the wedge angle created by the opening needs to be maintained at the edge of the suture with retractor forceps, which not only increases the complexity and time cost of the surgery but may also interfere with the subsequent placement of the plate. Summary of the Invention

[0003] To address the existing technical problems, this disclosure provides a retractor and retraction device suitable for high tibial osteotomy, which at least partially solves the above-mentioned technical problems. A drive mechanism drives a movable blade holder to move into the bone suture and retract the suture to a preset wedge angle. The drive mechanism also drives a support to rotate axially, changing the blade head to a holding blade head that maintains the preset wedge angle, thus improving the precision of the surgery and the ease of use.

[0004] Embodiments of this disclosure provide a retractor for opening bone sutures during high tibial osteotomy, comprising: a support, a first set of blades, a second set of blades, and a first actuating part. The first set of blades is disposed on the support and protrudes from the support along a first direction; the second set of blades is disposed on the support and protrudes from the support along a second direction forming a first angle with the first direction; the thickness of the first set of blades is configured to be greater than the thickness of the second set of blades. The first actuating part is configured to drive the support to rotate about a fixed axis of rotation, so that the first set of blades or the second set of blades faces and extends into the bone suture.

[0005] According to embodiments of this disclosure, the angle of the first included angle formed by the first direction and the second direction is configured to be between 90° and 180°.

[0006] According to an embodiment of the present disclosure, the first blade assembly and / or the second blade assembly have an extension portion and a bending portion. The extension portion extends in a direction orthogonal to the rotation axis, and the bending portion is formed in the extension portion and extends in a direction forming a second angle with the extension portion; the second angle is an obtuse angle.

[0007] According to an embodiment of the present disclosure, the first actuation unit includes a first motor, the output end of which is connected to the rotating shaft to output torque to the rotating shaft to rotate the rotating shaft about its axis.

[0008] According to an embodiment of this disclosure, the spreader includes a fixed blade holder, a movable blade holder, and a second actuating part. The fixed blade holder is disposed on the bracket; the movable blade holder is configured to move between a first position close to the fixed blade holder and a second position away from the fixed blade holder; and the second actuating part is disposed on the bracket and configured to drive the movable blade holder to move between the first position and the second position.

[0009] According to embodiments of this disclosure, the first and second knife groups each include a fixed knife and a movable knife. The fixed knife is disposed on the fixed knife holder, and the movable knife is disposed on the movable knife holder. The movable knife is configured to move relative to the fixed knife with the movable knife holder, so as to open the bone suture when the movable knife holder is in the second position.

[0010] According to an embodiment of this disclosure, the second actuation unit includes a second motor and a first lead screw. The second motor is disposed on the bracket; one end of the first lead screw is axially connected to the output end of the second motor, and the other end of the first lead screw is rotatably disposed through the bracket, wherein the movable tool holder is sleeved outside the first lead screw and meshes with the first lead screw.

[0011] Embodiments of this disclosure also provide a stretching device equipped with the stretcher described above, comprising a fixed platform and a movable platform. The fixed platform is suitable for supporting the bone to be stretched open; the movable platform is movably disposed on the fixed platform; the stretcher is disposed on the movable platform and moves with the movable platform.

[0012] According to an embodiment of this disclosure, the aforementioned spreading mechanism further includes a third actuating part configured to drive the moving platform to move between a third position close to the bone and a fourth position away from the bone; wherein, when the moving platform is in the third position, the first or second blade assembly faces and extends into the bone suture.

[0013] According to an embodiment of this disclosure, the first motor of the aforementioned expander is disposed on the aforementioned moving platform.

[0014] According to the retractor and retraction device for high tibial osteotomy provided in this disclosure, during high tibial osteotomy, both the first and second blade groups of the retractor are in a closed state. At this time, the first actuator drives the aforementioned support to rotate, causing the first blade group to enter the bone suture in a chisel-like manner, thereby opening the bone suture until the wedge angle formed by the bone suture reaches a preset value. After switching blade groups, the second blade group enters the bone suture to achieve secondary retraction of the bone suture, keeping the bone suture at the preset wedge angle, thereby achieving the function of maintaining the bone suture, accurately controlling the width of the bone suture, simplifying the surgical procedure, ensuring the continuity of the surgery, reducing the reliance on the surgeon's experience, making the surgical procedure more standardized and regulated, and improving the convenience and accuracy of the operation. Attached Figure Description

[0015] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0016] Figure 1 A perspective view of a spreader according to an embodiment of the present disclosure is shown schematically;

[0017] Figure 2(a) schematically shows a perspective view of the first blade assembly in a closed state according to an embodiment of the present disclosure;

[0018] Figure 2(b) schematically shows a perspective view of the first blade assembly in the open state according to an embodiment of the present disclosure;

[0019] Figure 3(a) schematically shows a perspective view of the second blade assembly in a closed state according to an embodiment of the present disclosure;

[0020] Figure 3(b) schematically shows a perspective view of the second blade assembly in the open state according to an embodiment of the present disclosure;

[0021] Figure 4 A perspective view of the spreading device according to an embodiment of the present disclosure is shown schematically.

[0022] Figure Labels

[0023] 1. Bracket;

[0024] 101. Turbine shaft;

[0025] 102. Connecting seat;

[0026] 2. First set of cutters;

[0027] 201. First cutter group, set the cutter position;

[0028] 2011, First blade assembly base;

[0029] 2012, First Extension;

[0030] 2013, First bend;

[0031] 202. The first cutting group begins to move;

[0032] 2021, Second blade assembly base;

[0033] 2022, Second Extension;

[0034] 2023, Second bend;

[0035] 3. Second set of cutters;

[0036] 301. Second cutter group, fixed cutter position;

[0037] 3011, Third blade assembly base;

[0038] 3012, Third Extension;

[0039] 3013, Third bend;

[0040] 302. The second set of cutters moves;

[0041] 3021, Fourth blade assembly base;

[0042] 3022, Fourth Extension;

[0043] 2023, Fourth bend;

[0044] 4. First Action Department;

[0045] 401. First motor;

[0046] 402. Worm gear;

[0047] 403, Turbine;

[0048] 5. Fix the tool holder;

[0049] 6. Move the tool holder;

[0050] 7. Second actuator;

[0051] 701. Second motor;

[0052] 702. Coupling;

[0053] 703, First leadscrew;

[0054] 8. Optical axis guide rail;

[0055] 9. Dynamic platform;

[0056] 10. Determine the platform;

[0057] 11. Third actuating part;

[0058] 1101, Guide rail;

[0059] 1102, Second lead screw. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0061] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0062] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0063] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0064] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure.

[0065] Figure 1 A perspective view of a spreader according to an embodiment of the present disclosure is shown schematically.

[0066] An exemplary embodiment of this disclosure provides a spreader, such as Figure 1As shown, the spreader is suitable for opening bone sutures. The spreader includes: a support 1, a first blade assembly 2, a second blade assembly 3, and a first actuating part 4. The first blade assembly 2 is disposed on the support 1 and protrudes from the support 1 along a first direction. The second blade assembly 3 is disposed on the support 1 and protrudes from the support 1 along a second direction (which may be the opposite direction of the X-axis in the figure) forming a first angle with the first direction (shown in the X-axis direction of the figure). The first actuating part 4 is configured to drive the support 1 to rotate about a turbine shaft 101 axially fixed, so that the first blade assembly 2 or the second blade assembly 3 faces and extends into the bone suture. The thickness of the first blade assembly 2 is configured to be less than the thickness of the second blade assembly 3.

[0067] In such an implementation, such as Figure 1 As shown, the first blade group 2 is a dilatation blade group, which dilatates the bone suture to a preset wedge angle. The second blade group 3 is a maintenance blade group, which maintains the bone suture to the preset wedge angle. The preset wedge angle is the angle at which the bone suture is ultimately dilatated, which can be calculated or obtained based on experience. The first actuator 4 drives the support 1 to rotate, causing the first blade group 2 to enter the bone suture in a chisel-like manner, thereby opening the bone suture until the wedge angle formed by the bone suture reaches the preset value. Then, the blade group is switched so that the second blade group 3 enters the bone suture (at this time, the first blade group 2 disengages from the bone suture), realizing a secondary dilatation of the bone suture and maintaining the bone suture at the preset wedge angle. This achieves the function of maintaining the width of the bone suture. The blade group can be flexibly switched to achieve the target, completing the dilatation and maintenance of the preset wedge angle, reducing the number of tool changes, simplifying the surgical procedure, improving surgical efficiency, and increasing operational flexibility and accuracy.

[0068] In this implementation, the width of the second blade assembly 3 along the Y direction can be one-fifth of the width of the first blade assembly 2, or it could be one-half, one-third, or other ratios. However, the thickness of the second blade assembly 3 along the Z direction is configured to be greater than the thickness of the first blade assembly 2, thereby balancing the reduction in strength caused by the reduced width. Since the bone undergoes plastic deformation after the initial opening, the second blade assembly 3, although thicker than the first blade assembly 2, can more easily enter the bone suture during the secondary opening. Simultaneously, the narrower second blade assembly 3 provides ample space for the placement of the fixation plate. Thus, the first blade assembly 2 can be inserted more easily into narrower bone sutures, reducing insertion resistance and the risk of damaging surrounding soft tissues, preventing instability. The second blade assembly 3 can be used for situations requiring greater support or dealing with wider bone sutures. Its thickness provides a larger contact area and support strength, enabling more stable opening of larger bone sutures.

[0069] In such an implementation, such as Figure 1As shown, the angle between the first direction in which the first blade assembly 2 is installed and the second direction in which the second blade assembly 3 is installed is configured to be between 90° and 180°. Specifically, this angle includes, but is not limited to, 90°, 135°, 180°, and any other arbitrary angle. Taking an angle less than 90° as an example, when this angle is too small, when one blade assembly (such as the first blade assembly 2) is working, the other blade assembly (such as the second blade assembly 3) will become an obstacle, thus interfering with the surgical procedure or obstructing the operator's field of vision. When the angle is configured to be 180°, the first blade assembly 2 is along the X-axis direction, and the second blade assembly 3 is in the opposite direction to the first blade assembly 2, that is, it is set in the opposite direction of the X-axis direction.

[0070] In one exemplary embodiment, such as Figure 1 As shown, the support 1 of the expander includes a main body, on which multiple partitions are sequentially arranged along the Z-axis extension direction, dividing the main body into multiple installation spaces. At least one installation space is suitable for accommodating the second actuating unit 7, and at least another installation space is suitable for accommodating the movable tool holder 6, as will be described in detail in the following embodiments. Furthermore, a turbine shaft 101 is also provided at the end of the main body of the support 1 away from the movable tool holder 6. The turbine shaft 101 coincides with the extension direction of the axis of the output shaft of the second motor 701 of the second actuating unit 7. The support 1 also includes a connecting seat 102 for housing the second motor 701.

[0071] In such embodiments, such as Figure 1 As shown, the spreader includes a fixed tool holder 5, a movable tool holder 6, and a second actuating part 7. The fixed tool holder 5 is disposed on the bracket 1. The movable tool holder 6 is configured to move between a first position close to the fixed tool holder 5 and a second position away from the fixed tool holder 5. The second actuating part 7 is disposed on the bracket 1 and configured to drive the movable tool holder 6 to move between the first position and the second position. The fixed tool holder 5 and the movable tool holder 6 are cuboid in shape. The fixed tool holder 5 is fixed to the bracket 1 and has a threaded hole along the X-axis extension direction; the movable tool holder 6 has a threaded hole and a guide hole in its middle part along the Z-axis extension direction. The movable tool holder 6 can restrict its movement path through the threaded hole and the guide hole, allowing the movable tool holder 6 to move between the first position and the second position.

[0072] In one exemplary embodiment, such as Figure 1As shown, the second actuation unit 7 includes a second motor 701 and a first lead screw 703. The second motor 701 is disposed in the mounting space of the bracket 1 near the turbine shaft 101. One end of the first lead screw 703 is connected to the output shaft of the second motor 701 via a coupling 702, and the other end is rotatably inserted through the mounting space of the bracket 1 where the fixed tool holder 5 is disposed. Furthermore, the movable tool holder 6 is sleeved outside the first lead screw 703 through a threaded hole and engages with the first lead screw 703. Furthermore, the expander also includes a light axis guide rail 8. The light axis guide rail 8 is parallel to the first lead screw 703 and passes through a guide hole between the movable tool holder 6 and the bracket 1, which can keep the movable tool holder 6 moving smoothly along the Z-axis direction. In this way, the second motor 701 can drive the first lead screw 703 through the coupling 702, so that the movable tool holder 6 moves relative to the fixed tool holder 5 between the first position and the second position, thereby expanding the bone suture.

[0073] In one exemplary embodiment, such as Figure 1 As shown, the first blade group 2 and the second blade group 3 each include a fixed blade (fixed blade 201 of the first blade group and fixed blade 301 of the second blade group) and a movable blade (movable blade 202 of the first blade group and movable blade 302 of the second blade group). The fixed blade (fixed blade 201 of the first blade group and fixed blade 301 of the second blade group) is disposed on the fixed blade holder 5, and the movable blade (movable blade 202 of the first blade group and movable blade 302 of the second blade group) is disposed on the movable blade holder 6; wherein, the movable blade (movable blade 202 of the first blade group and movable blade 302 of the second blade group) is configured to move with the movable blade holder 6 relative to the fixed blade (fixed blade 201 of the first blade group and fixed blade 301 of the second blade group) so as to open the bone suture when the movable blade holder 6 is in the second position.

[0074] Figure 2(a) schematically shows a perspective view of the first blade assembly in a closed state according to an embodiment of the present disclosure; Figure 2(b) schematically shows a perspective view of the first blade assembly in an open state according to an embodiment of the present disclosure; Figure 3(a) schematically shows a perspective view of the second blade assembly in a closed state according to an embodiment of the present disclosure; Figure 3(b) schematically shows a perspective view of the second blade assembly in an open state according to an embodiment of the present disclosure.

[0075] In one exemplary embodiment, the first blade assembly 2 and / or the second blade assembly 3 have an extension and a bending portion.

[0076] As shown in Figures 2(a) and 2(b), the fixed blade 201 of the first blade group includes a base 2011, a first extension 2012, and a first bending part 2013, and the moving blade 202 of the first blade group includes a base 2021, a second extension 2022, and a second bending part 2023.

[0077] As shown in Figures 3(a) and 3(b), the fixed blade 301 of the second blade group includes a base 3011 of the third blade group, a third extension 3012 and a third bending part 3013, and the moving blade 302 of the second blade group includes a base 3021 of the fourth blade group, a fourth extension 3022 and a fourth bending part 3023.

[0078] The extension is a sheet-like structure extending from the base of the blade assembly. After extending forward a suitable distance, it bends along the Z-axis, forming a bent section. When opening the bone suture, the bent section enters the suture, while the extension does not. The extension extends in a direction orthogonal to the axis of rotation of the turbine shaft 101. The bent section is formed in the extension and extends along a direction forming a second angle with the extension. This second angle is obtuse to avoid the situation where the extension line of the retractor body along the Z-axis intersects with the extension line of the bone, preventing the surgery from being impossible. The first blade assembly 2 and the second blade assembly 3 are pointed on the side facing the bone suture and gradually thicken towards the other side. This design allows the blade assembly to smoothly enter the initially narrow bone suture without reducing its strength. It avoids the situation where a uniformly thin blade is easily broken, and also avoids the situation where an excessively thick blade assembly cannot enter the bone suture of only 1 to 2 millimeters after osteotomy. At the same time, the size of the second angle can be set according to the actual situation to better adapt to the position and shape of the bone suture.

[0079] Figure 4 A perspective view of the spreading device according to an embodiment of the present disclosure is shown schematically.

[0080] This disclosure also provides a spreading device equipped with the above-mentioned spreader, such as... Figure 4 As shown, it includes a movable platform 9 and a fixed platform 10. The fixed platform 10 is suitable for supporting the bone to be opened. The movable platform 9 is movably disposed on the fixed platform 10; any of the above-mentioned expanders is disposed on the movable platform 9 and moves with the movable platform 9.

[0081] In one exemplary embodiment, such as Figure 4 As shown, the fixed platform 10 of the expansion device has a base plate at its bottom. Three side plates are sequentially arranged along the X-axis from the base plate, with the middle side plate being higher than the other two. A horizontal top plate extends along the X-axis from an appropriate position on the middle side plate to hold the bone to be expanded. The movable platform 9 is constructed as a block structure and is located on one side of the horizontal top plate. The movable platform 9 has threaded holes and guide holes along the X-axis.

[0082] In such an embodiment, the device is opened, such as Figure 4As shown, it also includes a third actuation unit 11, configured to drive the moving platform 9 to move between a third position close to the bone and a fourth position away from the bone; wherein, when the moving platform 9 is in the third position, the first blade assembly 2 or the second blade assembly 3 faces and extends into the bone suture. The third actuation unit 11 also includes a guide rail 1101, a second lead screw 1102 and a third motor (not shown in the figure). The moving platform 9 is sleeved outside the second lead screw 1102 through a threaded hole and engages with the second lead screw 1102. The guide rail 1101 is arranged parallel to the second lead screw 1102, and the moving platform 9 passes through the guide hole between the third and fourth positions, which can keep the moving platform moving smoothly in the X-axis direction. In this way, driven by the third motor, the second lead screw 1102 is driven to rotate axially, thereby driving the moving platform 9 to move between the third and fourth positions so that the spreader approaches or moves away from the bone to be spread in the bone suture, and when the moving platform 9 is in the third position, the first blade assembly 2 or the second blade assembly 3 can extend into and spread the bone suture.

[0083] In one exemplary embodiment, such as Figure 1 and Figure 4 As shown, the first actuation unit 4 includes a first motor 401. The output end of the first motor 401 is connected to the rotating shaft to output torque to the rotating shaft, causing the rotating shaft to rotate around its axis. The first motor 401 of the spreader is mounted on the moving platform 9 and moves with the moving platform 9. The first actuation unit 4 also includes a worm gear 402 and a turbine gear 403. The turbine gear 403 is connected to one side of the support 1 via a turbine shaft 101. The worm gear 402 is located below the turbine gear 403, and the axes of the worm gear 402 and the turbine gear 403 are perpendicularly intersecting and meshing with each other. The first motor 401 drives the worm gear 402 to rotate axially along the worm shaft, which in turn drives the turbine gear 403 to rotate axially along the turbine shaft 101, thereby driving the support 1 to rotate, thus realizing the cutting head conversion.

[0084] According to the tibial high osteotomy device and the tibial high osteotomy device provided in this embodiment, when performing tibial high osteotomy, the bone to be opened is placed on the fixed platform 10, and the third actuation unit 11 drives the moving platform 9 to approach the bone. In the initial state, the first blade group 2 faces upward and is perpendicular to the moving platform 9. The output end of the first motor 401 drives the rotating shaft to rotate around the axis, which drives the first blade group 2 to enter the bone suture in a bone chisel-like manner. The second motor 701 drives the first lead screw 703 to rotate, which drives the moving blade holder 6 to move to the second position. The first blade group 2 opens, and the bone suture opens to the preset wedge angle, realizing force line correction. After the preset wedge angle is achieved, it is maintained for a period of time to allow the bone to adapt to the wedge angle. The third actuator 11 drives the moving platform 9 to retract an appropriate distance. The first motor 401 drives the bracket 1 to rotate so that the second blade assembly 3 faces upward and remains perpendicular to the moving platform 9. The third actuator 11 drives the moving platform 9 to approach the bone again. The first motor 401 drives the rotating shaft to rotate around the axis, causing the second blade assembly 3 to approach and enter the bone suture. The second motor 701 drives the first lead screw 703 to rotate, causing the moving blade holder 6 to move to the second position, thus opening the second blade assembly 3. The bone suture is maintained at the preset wedge angle, and then the steel plate is placed. After the wedge angle is fixed, the second blade assembly 3 closes and exits the bone suture, completing the orthopedic task.

[0085] The retractor and retraction device of the above-disclosed embodiments are applicable to surgical types such as wedge-shaped high tibial osteotomy. When the retractor is activated, the motor's operation control depends on preoperative planning and intraoperative information feedback. By monitoring the motor current and power and setting a displacement encoder, the width of the first blade group 2 opening and the width of the second blade group 3 maintaining the opening are accurately determined, and the size of the preset wedge angle is calculated. Considering factors such as the patient's bone shape, hinge position, bone density, and correction angle, the retractor will automatically adjust its operating speed and activate risk assessment during operation to develop personalized correction plans for different patients. However, the above content is not within the scope of protection of this application, and any method for calculating the preset wedge angle can be applied to this application.

[0086] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A retractor suitable for high tibial osteotomy, used to open bone sutures, characterized in that, include: support; The first blade assembly is disposed on the bracket and protrudes from the bracket along the first direction; The second blade assembly is disposed on the bracket and protrudes from the bracket along a second direction that forms a first angle with the first direction; The first actuator is configured to drive the support to rotate about a fixed axis of rotation, so that the first or second blade assembly faces and extends into the bone suture. The thickness of the first blade group is configured to be less than the thickness of the second blade group.

2. The expander according to claim 1, characterized in that, The angle between the first direction and the second direction is configured to be between 90° and 180°.

3. The expander according to claim 1, characterized in that, The first blade assembly and / or the second blade assembly have an extension and a bending portion. The extension extends in a direction orthogonal to the rotation axis, and the bending portion is formed in the extension and extends in a direction forming a second angle with the extension. The second included angle is an obtuse angle.

4. The expander according to claim 1, characterized in that, The first actuation unit includes a first motor, the output end of which is connected to the rotating shaft to output torque to the rotating shaft to rotate the rotating shaft about its axis.

5. The expander according to any one of claims 1 to 4, characterized in that, Also includes: A fixed tool holder is mounted on the bracket; The movable tool holder is configured to move between a first position close to the fixed tool holder and a second position far away from the fixed tool holder; as well as A second actuator is disposed on the bracket and configured to drive the movable tool holder to move between the first position and the second position.

6. The expander according to claim 5, characterized in that, The first and second tool sets each include a fixed tool and a movable tool, the fixed tool being disposed on the fixed tool holder and the movable tool being disposed on the movable tool holder; The movable blade is configured to move relative to the fixed blade along with the movable blade holder, so as to open the bone suture when the movable blade holder is in the second position.

7. The expander according to claim 5, characterized in that, The second actuator includes: A second motor is mounted on the bracket; The first lead screw has one end shaft connected to the output end of the second motor, and the other end of the first lead screw is rotatably inserted through the bracket. The movable tool holder is sleeved outside the first lead screw and meshes with the first lead screw.

8. A distraction device suitable for high tibial osteotomy, characterized in that, include: A fixed platform, suitable for supporting bones whose sutures need to be opened; A movable platform, which is movably mounted on the fixed platform; The spreader as described in any one of claims 1 to 7 is disposed on the moving platform and moves with the moving platform.

9. The spreading device according to claim 8, characterized in that, It also includes a third actuator configured to drive the moving platform to move between a third position close to the bone and a fourth position away from the bone; When the moving platform is in the third position, the first or second blade group faces and extends into the bone suture.

10. The spreading device according to claim 8 or 9, characterized in that, The first motor of the spreader is mounted on the moving platform.

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