Anterior cruciate ligament reconstruction positioning assembly and method

Abstract

The application provides an ACL reconstruction positioning assembly and method, the assembly comprising an ACL tibial insertion point locator, an ACL tibial tunnel locator and an ACL femoral insertion point locator which are customized and printed by 3D printing; the method comprising extracting contour data information of a knee joint by CT or nuclear magnetic resonance, constructing a three-dimensional mathematical model of the knee joint, and designing the ACL tibial insertion point locator, the ACL tibial tunnel locator and the ACL femoral insertion point locator according to the three-dimensional mathematical model. The application adopts a three-dimensional reconstructed joint model, and determines each positioning part through the joint model, so that the positioning is accurate and reliable; meanwhile, the length of the ligament can be accurately calculated through the three-dimensional model, so that the risk caused by the ligament being too long or too short is avoided, and conditions are further created for improving the operation quality, reducing the operation failure rate, shortening the treatment time and reducing the treatment cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a positioning assembly and method for anterior cruciate ligament reconstruction. BACKGROUND

[0002] The anterior cruciate ligament originates from the medial anterior of the intercondylar eminence of the tibia, and is attached to the anterior horn of the lateral meniscus. The fibers are fan-shaped and attached to the medial side of the lateral femoral condyle. After the anterior cruciate ligament ruptures, the knee joint is unstable, affecting daily activities and sports, and causing further damage and degeneration of the intra-articular structure. Therefore, in order to restore the structure and function of the knee joint, the anterior cruciate ligament needs to be reconstructed.

[0003] Due to differences in body height, weight and bone structure, a uniform length of ligament cannot be used for replacement. In order to estimate the appropriate length, the existing technology relies on the experience of the surgical personnel to determine. Although this method has a certain reliability, it is highly dependent on the experience of the surgical personnel, and there is a great uncertainty, which affects the surgical effect.

[0004] In particular, the positioning of the femoral and tibial insertion points is crucial for anterior cruciate ligament reconstruction surgery and largely determines the success or failure of the surgery. Since there is no accurate positioning tool, current positioning mainly relies on the experience of the surgeon. In particular, for beginners, the accuracy is difficult to guarantee, which is an important reason for the failure of the surgery. The failure of anterior cruciate ligament reconstruction is mostly caused by inaccurate positioning.

[0005] Therefore, it is necessary to design a positioning assembly for anterior cruciate ligament reconstruction, which can quickly and easily determine the starting and ending points of the anterior cruciate ligament, and provide help for quickly and accurately determining the starting and ending points of the anterior cruciate ligament and estimating the length of the ligament. SUMMARY

[0006] The present application provides a positioning assembly and method for anterior cruciate ligament reconstruction, which can accurately position the starting and ending points and estimate the length of the anterior cruciate ligament, to solve the problem of low reconstruction efficiency and unstable quality caused by the lack of positioning tools in the prior art.

[0007] To solve the above technical problems, one embodiment of the present application provides the following technical scheme:

[0008] The positioning assembly for anterior cruciate ligament reconstruction comprises an ACL tibial insertion point locator, an ACL tibial tunnel locator and an ACL femoral insertion point locator made by 3D printing,

[0009] The ACL tibial insertion point locator comprises a horizontal rod and a vertical rod integrally arranged at one end of the horizontal rod, the horizontal rod is provided with a positioning hole for marking the tibial insertion point, and the end of the vertical rod is provided with a tibial insertion point positioning tip, the length of the tibial insertion point positioning tip matches the height of the slope behind the intercondylar spine of the tibia,

[0010] The ACL tibial tunnel locator comprises an ACL tibial tunnel entrance positioning tip and an ACL tibial tunnel exit positioning tip, and a holding portion is integrally arranged between the ACL tibial tunnel entrance positioning tip and the ACL tibial tunnel exit positioning tip,

[0011] The ACL femoral insertion point locator comprises an arc-shaped positioning block and a handle integrally arranged at the end of the arc-shaped positioning block, and the center of the arc-shaped positioning block is provided with a positioning hole for positioning the femoral insertion point.

[0012] Further, the distance between the positioning hole and the end of the horizontal rod close to the vertical rod is determined by preoperative CT measurement.

[0013] Further, the ACL tibial tunnel entrance positioning tip and the ACL tibial tunnel exit positioning tip are arranged at an angle of 135-155 degrees.

[0014] Further, the shape of the arc-shaped positioning block matches the edge of the lateral femoral condyle.

[0015] Further, a horizontal marking portion is arranged between the ACL tibial tunnel entrance positioning tip and the holding portion.

[0016] To solve the above technical problems, the second aspect of the present application provides the following technical scheme:

[0017] A positioning method for anterior cruciate ligament reconstruction, which adopts CT or nuclear magnetic resonance to extract contour data information of a knee joint, constructs a three-dimensional mathematical model of the knee joint, designs an ACL tibial insertion point locator, an ACL tibial tunnel locator and an ACL femoral insertion point locator according to the three-dimensional mathematical model, and the specific steps comprise:

[0018] S1, constructing a coordinate system;

[0019] Taking the center of the tibial medullary cavity as the Z axis, the intersection point between the plane of the top platform of the tibia and the Z axis as the coordinate origin, and the widest region of the top platform of the tibia as the X axis, a line passing through the origin and perpendicular to the X axis on the top platform of the tibia is the Y axis,

[0020] S2, determining the ACL tibial insertion point;

[0021] S3, determining the ACL femoral insertion point;

[0022] S4, constructing the ACL tibial insertion point locator;

[0023] 1) measure the height of the slope behind the intercondylar eminence of the tibia, which is the length of the vertical rod;

[0024] 2) measure the distance between the tibial insertion of the ACL and the starting point of the slope behind the intercondylar eminence of the tibia to determine the position of the positioning hole;

[0025] S5, construct an ACL tibial tunnel locator;

[0026] 1) take the tibial insertion as the tunnel entrance, and determine the tunnel direction at an angle of 45-65 degrees with the plane where the top platform of the tibia is located, and the intersection of the center line of the tunnel and the tibia model is the tunnel exit;

[0027] 2) extend the tunnel entrance to the Z-axis direction to form an ACL tibial tunnel entrance positioning tip, extend the tunnel exit along the tunnel direction to form an ACL tibial tunnel exit positioning tip, and then add an arc segment to form a holding part;

[0028] S6, construct an ACL femoral insertion locator;

[0029] Determine the arc of the arc positioning block with the edge of the lateral femoral condyle, and then determine the ACL femoral insertion by four-grid method or distance division method or tibial tunnel extension intersection method. The positioning hole is arranged on the ACL femoral insertion.

[0030] Further, it further comprises the steps of taking the ACL tibial insertion as the initial point and extending the femoral tunnel direction with the same slope of the tibial tunnel to form a femoral tunnel locator.

[0031] Further, it further comprises the steps of estimating the length of the implanted ligament: ligament length = tibial tunnel internal length + femoral tunnel internal length + connection length between femur and tibia.

[0032] The beneficial effects of the present application are:

[0033] The present application adopts three-dimensional reconstruction of joint model, and then determines each positioning member through the joint model, so that the positioning is accurate and reliable, and provides conditions for high-quality anterior cruciate ligament reconstruction surgery. At the same time, through the three-dimensional model, the length of the ligament can be accurately predicted, so as to avoid the situation that the length of the ligament is too long or too short, thereby affecting the surgical efficacy, and further create conditions for improving the quality of surgery, reducing the failure rate of surgery, shortening the treatment time, and reducing the treatment cost. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The flowchart of the present application;

[0035] Figure 2 The coordinate system for designing the positioning tool of the present application;

[0036] Figure 3 The schematic diagram for determining the ACL tibial insertion;

[0037] Figure 4 schematic view of the ACL femoral insertion site;

[0038] Figure 5 schematic view of the tibial tunnel locator in operation;

[0039] Figure 6 front view of the ACL tibial insertion site locator;

[0040] Figure 7 top view of the ACL tibial insertion site locator;

[0041] Figure 8 front view of the ACL femoral insertion site locator;

[0042] Figure 9 front view of the ACL tibial tunnel locator;

[0043] Figure 10 schematic view of the ligament total length calculation.

[0044] Reference signs:

[0045] 1 - ACL tibial insertion site locator; 2 - ACL tibial tunnel locator; 3 - ACL femoral insertion site locator; 4 - crossbar; 5 - vertical bar; 6 - positioning hole; 7 - tibial insertion site positioning tip; 8 - ACL tibial tunnel entry positioning tip; 9 - ACL tibial tunnel exit positioning tip; 10 - grip; 11 - horizontal marker; 12 - arc-shaped positioning block; 13 - handle; 14 - positioning hole. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0048] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0049] In the foregoing description of the present application, it should be noted that the terms "one side", "the other side" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed during use, and are merely for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0050] In addition, the term "same" and the like do not mean that the components must be absolutely the same, but there can be slight differences. The term "vertical" only means that the positional relationship between the components is more vertical than "parallel", and does not mean that the structure must be completely vertical, but can be slightly inclined.

[0051] The present application proposes a positioning method in anterior cruciate ligament reconstruction, the main process is as shown in Figure 1

[0052] First, extract the contour data information of the knee joint by CT or nuclear magnetic resonance, construct a three-dimensional mathematical model of the knee joint, then design ACL tibial stop locator 1, ACL tibial tunnel locator 2 and ACL femoral stop locator 3 according to the three-dimensional mathematical model, the specific design process includes:

[0053] S1, construct a tibial coordinate system;

[0054] As shown in Figure 2 , the center of the tibial medullary cavity is the Z axis, the intersection point of the plane where the top platform of the tibia is located and the Z axis is the coordinate origin, the widest region of the top platform surface of the tibia is the X axis, and the line passing through the origin and perpendicular to the X axis in the top platform surface of the tibia is the Y axis,

[0055] S2, determine the ACL tibial stop: the X coordinate is the same as the highest point of the intercondylar spine, that is, consistent with the X coordinate of the highest point of the intercondylar spine, the Y coordinate is the Y axis position of any point within the range of 15-30mm extending along the back of the intercondylar spine, and the Z coordinate is the Z axis position of the projection point of the space point composed of the X coordinate and the Y coordinate on the top platform surface of the tibia, thereby constructing the three-dimensional coordinate point of the ACL tibial stop, as shown in Figure 3

[0056] ​​S3, determine the ACL femoral insertion point; the plane of the femoral condyle is divided into a four-by-four grid, and the second vertical grid and the third horizontal grid are the region where the ACL femoral insertion point is located. Then, the specific point is determined according to the principle that the insertion point is basically consistent with the edge of the femoral condyle. This can avoid the problem of insufficient fixation due to being too close to the edge, making the fixation more reliable, as shown in Figure 4 .

[0057] S4, construct an ACL tibial insertion point locator;

[0058] 1) Measure the height of the slope behind the tibial intercondylar ridge. This height is the length of the vertical rod, so that when the Y direction is defined, there is no interference;

[0059] 2) Measure the distance between the ACL tibial insertion point and the starting point of the slope behind the tibial intercondylar ridge to determine the position of the positioning hole, thereby constructing an ACL tibial insertion point locator, as shown in Figure 6 , 7 .

[0060] S5, construct an ACL tibial tunnel locator;

[0061] 1) Take the tibial insertion point as the tunnel entrance, and determine the tunnel direction by making an angle with the plane of the tibial top platform. The intersection of the center line of the tunnel and the tibial model is the tunnel exit. The angle is not limited and can be any value within the range of 45-65 degrees, which can be selected according to the actual situation;

[0062] 2) Extend the tunnel entrance in the Z-axis direction to form an ACL tibial tunnel entrance positioning spike. Extend the tunnel exit outward along the tunnel direction to form an ACL tibial tunnel exit positioning spike. Add an arc segment to form a holding part, and construct an ACL tibial tunnel locator, as shown in Figure 9 .

[0063] S6, construct an ACL femoral insertion point locator;

[0064] Determine the arc of the arc-shaped positioning block with the edge of the femoral condyle. The positioning hole is set on the ACL femoral insertion point, and a positioning model is constructed, as shown in Figure 8 . In addition to the four-grid method described above, the tibial tunnel can also be determined by distance division or tibial tunnel extension intersection.

[0065] In this embodiment, the steps of determining the femoral tunnel locator are also included. In general, the straight line method can be used, that is, taking the ACL tibial insertion point as the initial point and extending the femoral tunnel in the same slope as the tibial tunnel. This makes it simple to make the locator and easy to calculate the length value.

[0066] In this embodiment, a step of estimating the length of the ligament to be implanted is also included. The method for estimating the length of the ligament proposed by the inventor is: the length of the ligament = the length in the tibial tunnel + the length in the femoral tunnel + the length between the femur and the tibia. As shown in Figure 10 , the length in the tibial tunnel is L, the length in the femoral tunnel is M, and the length between the femur and the tibia is N. Therefore, the length of the ligament to be implanted is: L + M + N.

[0067] In this embodiment, after the positioning assembly is constructed, 3D printing is performed to manufacture the following finished product:

[0068] The ACL tibial insertion locator, as shown in Figure 6 , 7 , includes a horizontal rod 4 and a vertical rod 5 integrally arranged at one end of the horizontal rod. The horizontal rod is provided with a positioning hole 6 for marking the position of the ACL tibial insertion. The end of the vertical rod is provided with a tibial insertion positioning tip 7. The length of the tibial insertion positioning tip matches the height of the slope behind the intercondylar ridge of the tibia,

[0069] The ACL tibial tunnel locator, as shown in Figure 9 , includes an ACL tibial tunnel entrance positioning tip 8 and an ACL tibial tunnel exit positioning tip 9. A holding portion 10 is integrally arranged between the ACL tibial tunnel entrance positioning tip and the ACL tibial tunnel exit positioning tip, which can be used for positioning operation,

[0070] Meanwhile, a horizontal marker 11 is arranged between the ACL tibial tunnel entrance positioning tip and the holding portion, which can be used for judging the parallelism with the top platform surface of the tibia,

[0071] The ACL femoral insertion locator, as shown in Figure 8 , includes an arc-shaped positioning block 12 and a handle 13 integrally arranged at the end of the arc-shaped positioning block. The center of the arc-shaped positioning block is provided with a positioning hole 14 for positioning the femoral insertion,

[0072] The distance between the positioning hole of this embodiment and the end of the horizontal rod close to the vertical rod is not limited and can be set according to the CT measurement result.

[0073] Since the ACL tibial tunnel entrance positioning tip extends upward along the vertical direction and has an inclination angle of 45-65 degrees, the ACL tibial tunnel entrance positioning tip and the ACL tibial tunnel exit positioning tip form an included angle of 135-155 degrees, as shown in Figure 5 .

[0074] When positioning the tibial insertion, the horizontal rod of the ACL tibial insertion locator is parallel to the Y axis, and the vertical rod is adjusted to be parallel to the Z axis. Then, the front and back directions are adjusted so that the positioning tip is placed below the slope behind the intercondylar ridge of the tibia. At this time, the position corresponding to the tibial insertion positioning hole on the horizontal rod is the insertion point of the ACL on the tibia, which can be marked.

[0075] When the tibial tunnel is positioned, first, the tool is parallel to the Y axis, then the ACL tibial tunnel entrance positioning tip is coincided with the tibial stop point, then the horizontal mark part is adjusted to be parallel to the tibial top platform surface, at this time, the area pointed by the ACL tibial tunnel exit positioning tip is the ACL tibial tunnel exit area, then the area is marked,

[0076] When the femoral stop point is positioned, first, the arc-shaped positioning block is aligned with the femoral condyle edge, then the handle is rotated to make the holding part basically consistent with the Z axis direction, at this time, the positioning hole is the femoral stop point position,

[0077] At the stop point position, along the tibial tunnel direction, the femoral tunnel positioning tool is used to mark, so that the femoral tunnel is positioned and marked.

[0078] Through the above operation, the surgical personnel can quickly mark the position, so that the reconstruction surgery is efficient and accurate. Since the three-dimensional reconstruction is combined with the reality, the positioning is extremely accurate, the requirement for the medical personnel is significantly reduced. Since the accurate simulation is performed in the three-dimensional, the length of the ligament can be accurately calculated, so that the reliability of the surgery is improved, the risk of graft waste caused by too long ligament or fixation failure caused by too short ligament is avoided.

[0079] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. An anterior cruciate ligament reconstruction positioning assembly, characterized by: The ACL tibial stop locator, the ACL tibial tunnel locator and the ACL femoral stop locator are customized by 3D printing, The ACL tibial stop locator comprises a horizontal rod and a vertical rod integrally arranged at one end of the horizontal rod, the horizontal rod is provided with a positioning hole for marking the tibial stop, and the end of the vertical rod is provided with a tibial stop positioning tip, the length of the tibial stop positioning tip matches the height of the posterior slope of the intercondylar eminence of the tibia, The ACL tibial tunnel locator comprises an ACL tibial tunnel entrance positioning tip and an ACL tibial tunnel exit positioning tip, and a holding part is integrally arranged between the ACL tibial tunnel entrance positioning tip and the ACL tibial tunnel exit positioning tip, The ACL femoral stop locator comprises an arc-shaped positioning block and a handle integrally arranged at the end of the arc-shaped positioning block, and the center of the arc-shaped positioning block is provided with a positioning hole for positioning the femoral stop.

2. The anterior cruciate ligament reconstruction positioning assembly according to claim 1, wherein: The distance between the positioning hole and the end of the horizontal rod close to the vertical rod is determined according to the preoperative CT measurement.

3. The anterior cruciate ligament reconstruction positioning assembly according to claim 1, wherein: The ACL tibial tunnel entrance positioning tip and the ACL tibial tunnel exit positioning tip are arranged at an angle of 135-155 degrees.

4. The anterior cruciate ligament reconstruction positioning assembly according to claim 1, wherein: The shape of the arc-shaped positioning block matches the edge of the lateral femoral condyle.

5. The anterior cruciate ligament reconstruction positioning assembly according to claim 1, wherein: A horizontal marking part is arranged between the ACL tibial tunnel entrance positioning tip and the holding part.

6. A method of constructing an anterior cruciate ligament reconstruction positioning assembly as claimed in any one of claims 1 to 5, wherein: The surface contour data of the knee joint is extracted by CT or nuclear magnetic resonance, a three-dimensional mathematical model of the knee joint is constructed, and the ACL tibial stop locator, the ACL tibial tunnel locator and the ACL femoral stop locator are designed according to the three-dimensional mathematical model, and the specific steps comprise: S1, constructing a coordinate system; The center of the tibial medullary cavity is taken as the Z axis, the intersection point between the plane of the tibial top platform and the Z axis is taken as the coordinate origin, the widest region of the tibial top platform surface is taken as the X axis, and the line passing through the origin and perpendicular to the X axis in the tibial top platform surface is taken as the Y axis, S2, determining the ACL tibial stop; S3, determining the ACL femoral stop; S4, constructing the ACL tibial stop locator; 1) measuring the height of the posterior slope of the intercondylar eminence of the tibia, which is the length of the vertical rod; 2) measuring the distance between the ACL tibial stop and the starting point of the posterior slope of the intercondylar eminence of the tibia to determine the position of the positioning hole; S5, constructing the ACL tibial tunnel locator; 1) taking the tibial stop as the tunnel entrance, and determining the direction of the tunnel at an angle of 45-65 degrees with the plane of the tibial top platform, and the intersection point of the center line of the tunnel and the tibial model is the tunnel exit; 2) extending the tunnel entrance to the Z axis direction to form the ACL tibial tunnel entrance positioning tip, extending the tunnel exit along the tunnel direction to form the ACL tibial tunnel exit positioning tip, and adding an arc-shaped segment to form the holding part; S6, constructing the ACL femoral stop locator; The arc shape of the arc-shaped positioning block is determined by the edge of the lateral femoral condyle, and the ACL femoral stop is determined by the four-grid method or the distance division method or the tibial tunnel extension intersection method, and the positioning hole is arranged on the ACL femoral stop.

7. The method of construction of claim 6, wherein: It also includes the steps of determining the femoral tunnel locator by extending the femoral tunnel at the same slope of the tibial tunnel with the tibial stop as the initial point.

8. The method of construction of claim 7, wherein: Also included is a step of estimating the length of the ligament to be implanted, the length of the ligament = the length inside the tibial tunnel + the length inside the femoral tunnel + the length of the connection between the femur and the tibia. Also included is a step of estimating the length of the ligament to be implanted, the length of the ligament = the length inside the tibial tunnel + the length inside the femoral tunnel + the length

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