A ligament graft fixation device

Abstract

The present invention discloses a ligament graft fixation device, which respectively sets a femoral end unfolding structure and a tibial end unfolding structure on the femoral end column and the tibial end column; first through holes, second through holes and third through holes are respectively set on the tibial end of the push rod and the unfolding ends of the two unfolding structures, which are respectively used for the split beam parts at both ends of the ligament graft to pass through. After entering the bone tunnel, the femoral end unfolding structure can unfold in the trapezoidal bone tunnel on the femoral side to form an umbrella-shaped structure and be fixed there, and the tibial end unfolding structure can unfold in the trapezoidal bone tunnel on the tibial side to form an umbrella-shaped structure and be fixed there. After the ligament graft is implanted, the split beam parts at both ends are bilateral umbrella-shaped, realizing large-area contact with the bone surface in the tension direction, which is beneficial to better restoring the postoperative joint kinematics and the normal force conduction mode of the tendon-bone interface.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular relates to a ligament graft fixation device. Background Art

[0002] The anterior cruciate ligament (ACL) is one of the most important ligaments in the knee joint. Its macroscopic morphology is hourglass-shaped, with the thinnest part in the middle of the ligament and the larger the cross-sectional area as it approaches the bone surface on both sides. The ACL has the function of limiting excessive anterior displacement, internal rotation and eversion of the tibia. Because of the important role of the ACL in bearing joint forces, its injury is also one of the most common kinematic injuries, and complete tears are common clinically. At this time, most patients need to choose surgical treatment. The current mainstream surgical treatment method is ACL reconstruction, which is to replace the native ACL with a transplanted ligament and fix the two ends of the transplanted ligament in the femoral and tibial bone tunnels respectively. However, existing ACL reconstruction surgeries mostly use columnar grafts with a basically constant cross-sectional area, which are placed in bilateral bone tunnels by hanging fixation or compression fixation. The anatomical morphology, area and corresponding biomechanical function of the ACL bone attachment point (ACL-bone interface) are not restored, which leads to a series of postoperative complications, mainly manifested in abnormal joint kinematics, abnormal stress on articular cartilage leading to postoperative arthritis, and poor healing of the tendon-bone interface due to the small contact area between the transplanted ligament and the bone in the tension direction, which in turn leads to problems such as bone tunnel enlargement, graft loosening, and fixation failure.

[0003] The existing ACL transplant ligament has a columnar shape with a basically constant cross-sectional area, and its existing fixation technologies include extrusion fixation, suspension fixation and transbone fixation. In extrusion fixation, a screw is placed between the transplant ligament and the bone tunnel and drilled in. The lateral extrusion force creates a large static friction along the direction of the bone tunnel to prevent the transplant ligament from slipping out. The suspension fixation method is to clamp the top of the ligament through the cortical bone outside the tunnel so that it is suspended in the bone tunnel to prevent it from slipping out of the bone tunnel and into the joint cavity. The transbone tunnel fixation method is similar to the suspension fixation, the difference is that the bone needle can be completely inserted into the bone, the foreign body sensation can be reduced under the skin, and the length requirement for the transplant ligament is lower.

[0004] The above method still has the following disadvantages:

[0005] 1. The cross-sectional area of ​​existing transplanted ligaments is almost constant and columnar in shape. When the cross-sectional area is too small, the joint stability after surgery cannot be restored. When the cross-sectional area is too large, the middle of the transplanted ligament will collide with the top of the femoral intercondylar fossa, causing the transplanted ligament to fail. Moreover, the columnar transplanted ligament cannot simultaneously restore the tightness of each degree of freedom of the joint, causing abnormal stress in the articular cartilage and premature occurrence of arthritis after surgery.

[0006] 2. The existing transplant ligament fixation method is only applicable to transplant ligaments with a constant cross-sectional area, and cannot achieve the fixation of hourglass / umbrella-shaped transplant ligaments;

[0007] 3. Existing fixation methods have relatively high requirements for the length of the transplanted ligament. Especially for suspension fixation, it often requires the transplanted ligament to be distributed throughout the bone tunnel.

[0008] 4. Existing fixation methods are only applicable to transplanted ligaments with a relatively small cross-sectional area. For example, common suspension fixation often requires a longer bone tunnel. Therefore, the cross-sectional area of the bone tunnel should be small to ensure that not too much bone mass of the femoral condyle is lost. However, a smaller cross-sectional area will limit the contact area between the transplanted ligament and the bone in the tension direction, resulting in non-union of the tendon-bone interface and thus causing the failure of interface fixation after surgery.

[0009] 5. Existing fixation methods make the main contact surface between the transplanted ligament and the bone parallel to the ligament tension direction. Therefore, the ligament-bone interface is mainly subjected to shear force, which is completely different from the stress mode of the normal ACL-bone interface. The normal ACL-bone interface is mainly subjected to tensile force perpendicular to the interface. Therefore, the interface has gradually evolved into a four-layer microstructure, and the stiffness increases progressively from the ligament to the bone, which is beneficial to reducing the stress concentration phenomenon at the ligament-bone interface. The stress mode of the existing fixation method interface does not have such a force conduction function. Summary of the Invention

[0010] To solve the above problems, the present invention provides a ligament graft fixation device, and the technical solution is as follows:

[0011] A ligament graft fixation device of the present invention includes:

[0012] A push rod, a femoral end column is detachably connected to the femoral end of the push rod, a first through hole is opened at the tibial end of the push rod, and a tibial end column is detachably connected to the tibial end of the push rod;

[0013] A femoral end expansion structure, the fixed end of the femoral end expansion structure is installed at the femoral end of the femoral end column, and the expansion end of the femoral end expansion structure is used for radially expanding outward towards the push rod; and at least one second through hole is provided on the expansion end of the femoral end expansion structure;

[0014] A tibial end expansion structure, the fixed end of the tibial end expansion structure is installed on the tibial end column, and the expansion end of the tibial end expansion structure is used for radially expanding outward towards the push rod; and at least one third through hole is provided on the expansion end of the tibial end expansion structure;

[0015] The femoral end and the tibial end of the graft are respectively configured as at least one first sub-bundle and at least one second sub-bundle. The first sub-bundle is configured to pass through the corresponding second through hole and form a first closed loop with the graft, and the second sub-bundle is configured to sequentially pass through the corresponding first through hole and the third through hole to form a second closed loop;

[0016] After the pusher rod and the femoral end deployment structure and the tibial end deployment structure thereon are configured for the target object, the femoral end deployment structure and the first sub-bundle radially expand outwards and fit to the first position of the target object. The pusher rod withdraws from the femoral end column. The tibial end deployment structure and the second sub-bundle radially expand outwards and fit to the second position of the target object. After the deployment is completed, the tibial end of the graft is fixed to the target object, the relative positions of the femoral end deployment structure and the tibial end deployment structure and the target object are fixed, and the pusher rod withdraws from the target object.

[0017] For the ligament graft fixing device of the present invention, the femoral end deployment structure includes a plurality of femoral end deployment rods, a plurality of intermediate rods, a push ring, an elastic limiting member and a push rod;

[0018] The first ends of the femoral end deployment rods are respectively surrounded and rotatably connected to the first end of the femoral end column; at least one of the second through holes is provided on the femoral end deployment rods;

[0019] The push ring is axially slidably connected to the femoral end column along the femoral end column;

[0020] The first ends of the intermediate rods are respectively rotatably connected to the corresponding femoral end deployment rods, and the second ends of the intermediate rods are respectively rotatably connected to the push ring;

[0021] The elastic limiting member is telescopically arranged on the femoral end column, and the limiting surface facing the first end surface of the femoral end column is the limiting surface of the elastic limiting member;

[0022] The push rod is configured to extend into the target object and push the push ring to slide towards the first end of the femoral end column. Under the action of the intermediate rod, the corresponding femoral end deployment rod rotates, and the second end of the femoral end deployment rod gradually moves away from the femoral end column. The push ring slides over the elastic limiting member and abuts against the limiting surface, and the femoral end deployment rod expands and is positioned at the first position of the target object; after the deployment is completed, the push rod withdraws from the target object.

[0023] For the ligament graft fixing device of the present invention, the femoral end column is a hollow column, and a limiting notch corresponding to the elastic limiting member is provided on the side wall of the hollow column;

[0024] The elastic limiting member includes an elastic rod and a limiting member; the first end of the elastic rod is fixed to the inner wall surface of the hollow column, the second end of the elastic rod is provided with the limiting member, and the limiting member extends out of the limiting notch under the elastic force of the elastic rod;

[0025] The limiting member includes the limiting surface facing the first end of the femoral end column and the guiding inclined surface facing the second end of the femoral end column; the pushing ring moves into contact with the guiding inclined surface and pushes the limiting member to retract into the limiting notch against the elastic force of the elastic rod.

[0026] For the ligament graft fixation device of the present invention, the push rod includes a long rod and an annular structure and a clamping structure respectively arranged at both ends of the long rod;

[0027] A avoiding notch corresponding to the elastic limiting member is provided on the annular structure, and the clamping structure is a transverse extension plate extending radially outward along the push rod.

[0028] For the ligament graft fixation device of the present invention, the tibial end unfolding structure includes a plurality of tibial end unfolding rods;

[0029] The first ends of the tibial end unfolding rods are respectively surrounded and rotatably connected to the first end of the tibial end column; at least one of the third through holes is provided on the tibial end unfolding rod;

[0030] After the femoral end unfolding structure unfolds, the push rod is disassembled and separated from the femoral end column, and drives the tibial end column thereon to move towards the second position of the target object. The tibial end unfolding rod rotates under the pulling action of the graft, and the second end of the tibial end unfolding rod gradually moves away from the tibial end column and is positioned at the second position of the target object; after the tibial end unfolding structure unfolds, the push rod is disassembled and separated from the tibial end column and exits the target object.

[0031] For the ligament graft fixation device of the present invention, barbed tooth-like structures are provided on both the second end of the femoral end unfolding rod and the second end of the tibial end unfolding rod.

[0032] For the ligament graft fixation device of the present invention, along the first end to the second end of the femoral end unfolding rod, a plurality of the second through holes are respectively evenly distributed on the femoral end unfolding rod;

[0033] Along the first end to the second end of the tibial end unfolding rod, a plurality of the third through holes are respectively evenly distributed on the tibial end unfolding rod.

[0034] For the ligament graft fixation device of the present invention, an annular extension structure is formed on both the first end of the femoral end column and the first end of the tibial end column by extending radially outward; a plurality of first connection notches are arranged at intervals along the circumferential direction on the annular extension structure, and a first rotating shaft is provided in the first connection notch;

[0035] The first end of the femoral end deployment rod and the first end of the tibial end deployment rod respectively extend into the first connection notches of the corresponding annular extension structures, and are rotatably connected to the corresponding first rotating shafts.

[0036] For the ligament graft fixation device of the present invention, the intermediate rod includes two side rods corresponding to the femoral end deployment rod;

[0037] A plurality of second connection notches are arranged at intervals along the circumferential direction on the pushing ring, and second rotating shafts are provided in the second connection notches;

[0038] Third rotating shafts are provided on the femoral end deployment rod and extend out on both sides thereof;

[0039] The first end of the side rod extends into the corresponding second connection notch and is rotatably connected to the second rotating shaft; the second end of the side rod is rotatably connected to the corresponding side of the third rotating shaft.

[0040] For the ligament graft fixation device of the present invention, the pushing rod is a threaded rod; threaded holes corresponding thereto are respectively provided on the femoral end column and the tibial end column, and are respectively threadedly connected to the threaded rod.

[0041] Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art:

[0042] 1. In an embodiment of the present invention, a femoral end deployment structure and a tibial end deployment structure are respectively arranged on the femoral end column and the tibial end column on the pushing rod; first through holes, second through holes and third through holes are respectively arranged on the tibial end of the pushing rod and the deployment ends of the two deployment structures, and are respectively used for passing through the split parts at both ends of the ligament graft. After entering the bone tunnel, the femoral end deployment structure can be deployed in the trapezoidal bone tunnel on the femoral side to form an umbrella-shaped structure and be fixed there, and the tibial end deployment structure can be deployed in the trapezoidal bone tunnel on the tibial side to form an umbrella-shaped structure and be fixed there. After the ligament graft is implanted, the split parts at both ends are in a bilateral umbrella shape, realizing large-area contact with the bone surface in the tension direction, which is beneficial to better restoring the postoperative joint kinematics; more specifically, the main body fibers in the middle of the ligament graft are longitudinally arranged, and the auxiliary fibers are transversely arranged, which is beneficial to maintaining the small diameter characteristic in the middle. The split parts at both ends are locally bundled and scattered, and the fiber spacing gradually increases to increase the bone contact area. The space between adjacent split parts can accommodate the newly formed fibrous tissue, providing feasibility for further tissue transformation in vivo.

[0043] 2. In one embodiment of the present invention, the fixing device can be connected to the umbrella-shaped ligament graft and realize a small diameter before surgery, which is convenient for minimally invasive surgery implantation. After surgery, the bone end part of the transplanted ligament is unfolded to realize the physiological bilateral umbrella-shaped shape of the graft. In addition, the matching threads of the push rod and the femoral end column and the tibial end column allow the push rod to gradually complete the insertion and expansion steps of the ligament graft, and completely unscrew it after the bilateral expansion structure is expanded. Similarly, the push rod made of memory alloy with an opening on one side can also be completely withdrawn after completing the expansion task of the femoral end expansion structure. In addition, the side of each expansion rod is provided with a barbed tooth structure at the position where it contacts the bone surface, which is used to increase the friction between the fixing device and the bone surface and enhance the fixation effect.

[0044] 3. In one embodiment of the present invention, the ligament graft has a large area of ​​contact with the bone surface in the tension direction, while the contact area with the bone in the direction perpendicular to the tension direction of the ligament graft is small, which can effectively improve the force conduction mode of the tendon-bone interface, and is conducive to reducing the problems of bone tunnel expansion, graft loosening and fixation failure caused by abnormal tendon-bone interface force; this embodiment can improve the abnormal tendon-bone interface force conduction mode caused by the prior art, promote the normal healing of the tendon-bone interface, and restore its normal force conduction function; at the same time, the hourglass-shaped macro-anatomical morphology of the ligament graft is realized to better restore the joint kinematics after ACL reconstruction, reduce abnormal stress of articular cartilage, and avoid the premature occurrence of postoperative arthritis. In addition, this embodiment can be applied to shorter transplanted ligaments with larger cross-sectional areas, and this technology allows the ligament graft to have an hourglass-shaped macro-morphology, which can ensure that it has a higher mechanical strength while avoiding the collision phenomenon with the top of the intercondylar fossa caused by the excessive cross-sectional area of ​​the middle part of the ligament graft during joint flexion, and can effectively stabilize the knee joint while avoiding the impact and fracture of the ligament graft. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic diagram of the ligament graft fixation device of the present invention in an expanded state;

[0046] Figure 2 A front view of the ligament graft fixation device of the present invention in an expanded state;

[0047] Figure 3 is a cross-sectional view of the ligament graft fixation device of the present invention in an expanded state in a side view direction;

[0048] Figure 4 is a schematic diagram of the ligament graft fixation device of the present invention in a deployed state in a bone tunnel;

[0049] Figure 5 is a schematic diagram of the closed state of the ligament graft fixation device of the present invention;

[0050] Figure 6Front view of the closed state of the ligament graft fixation device of the present invention;

[0051] Figure 7 Cross-sectional view of the closed state of the ligament graft fixation device of the present invention in the side view direction;

[0052] Figure 8 Schematic diagram of the closed state of the ligament graft fixation device of the present invention with a ligament graft;

[0053] Figure 9 Schematic diagram of the usage steps of the ligament graft fixation device of the present invention in ACL reconstruction surgery.

[0054] Explanation of reference numerals: 1: Pushing rod; 2: Femoral end column; 3: Tibial end column; 4: Femoral end deployment rod; 5: Pushing ring; 6: Side rod; 7: Elastic limiting member; 701: Elastic rod; 702: Limiting member; 8: Tibial end deployment rod; 9: First through hole; 10: Second through hole; 11: Third through hole; 12: Ligament graft; 13: First sub-bundle; 14: Second sub-bundle; 15: Bone tunnel; 16: Femoral side; 17: Tibial side; 18: Pushing rod; 1801: Long rod; 1802: Ring structure; 1803: Clamping structure. Detailed description of the specific implementation

[0055] The following further describes in detail a ligament graft fixation device proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description and claims, the advantages and features of the present invention will be clearer.

[0056] See Figures 1 to 8 , in one embodiment, a ligament graft fixation device includes a pushing rod 1, a femoral end column 2, a tibial end column 3, a femoral end deployment structure, and a tibial end deployment structure.

[0057] The femoral end of the pushing rod 1 is detachably connected to the femoral end column 2. A first through hole 9 is formed at the tibial end of the pushing rod 1 for temporarily fixing the free segment of the tibial end ligament graft 12. And a tibial end column 3 is detachably connected to the pushing rod 1 (that is, the tibial end column 3 is located between the femoral end column 2 and the first through hole 9).

[0058] The fixed end of the femoral end deployment structure is installed at the first end of the femoral end column 2, and the deployment end of the femoral end deployment structure is used to expand radially outward towards the pushing rod 1. And at least one second through hole 10 is provided on the deployment end of the femoral end deployment structure.

[0059] The fixed end of the tibial end deployment structure is installed on the tibial end column 3, and the deployment end of the tibial end deployment structure is used to expand radially outward towards the pushing rod 1. And at least one third through hole 11 is provided on the deployment end of the tibial end deployment structure.

[0060] The middle part of the ligament graft 12 is a hollow dense mesh structure within the physiological length range (which can be set to surround the push rod 1), the main fibers are woven along the long axis of the native ligament, and the auxiliary fibers are woven perpendicular to the long axis of the ligament to provide lateral tension to constrain the lateral displacement between fibers. The femoral end and the tibial end of the ligament graft 12 are respectively configured as at least one first bundle 13 and at least one second bundle 14, the first bundle 13 and the second bundle 14 are both fiber bundle structures, the first bundle 13 is configured to pass through the corresponding second through hole 10 and form a first closed loop with the ligament graft 12, and the second bundle 14 is configured to pass through the corresponding first through hole 9 and the third through hole 11 in sequence to form a second closed loop.

[0061] After the push rod 1 and the femoral end deployment structure and tibial end deployment structure thereon are configured with the bone tunnel 15, the femoral end deployment structure and the first bundle 13 are radially deployed outward to form an umbrella-shaped structure and fit to the inverted trapezoidal bone groove on the femoral side 16 of the bone tunnel 15, the push rod 1 is rotated out of the femoral end column 2, the tibial end deployment structure and the second bundle 14 are radially deployed outward to form an umbrella-shaped structure and fit to the inverted trapezoidal bone groove on the tibial side 17 of the bone tunnel 15, after the deployment is completed, the tibial end of the ligament graft 12 can be fixed to the tibial side 17 by means of a titanium plate with a loop, etc., after the relative positions of the femoral end deployment structure and the tibial end deployment structure and the bone tunnel 15 are fixed, the push rod 1 withdraws from the bone tunnel 15.

[0062] In this embodiment, a femoral end expansion structure and a tibial end expansion structure are respectively arranged on the femoral end column 2 and the tibial end column 3 on the push rod 1; a first through hole 9, a second through hole 10 and a third through hole 11 are respectively arranged on the tibial end of the push rod 1 and the expansion ends of the two expansion structures, respectively for passing the bundle parts at both ends of the ligament graft 12. After entering the bone tunnel 15, the femoral end expansion structure can be expanded in the inverted trapezoidal bone tunnel 15 on the femoral side 16 to form an umbrella-shaped structure and fixed there, and the tibial end expansion structure can be expanded in the inverted trapezoidal bone tunnel 15 on the tibial side 17 to form an umbrella-shaped structure and fixed there. After the ligament graft 12 is implanted, the bundles at both ends are bilaterally umbrella-shaped, achieving large-area contact with the bone surface in the tension direction, simulating the bilateral umbrella-shaped (overall hourglass-shaped) morphology of the native ACL, and facilitating better recovery of postoperative joint kinematics; in more detail, the main fibers in the middle of the ligament graft are arranged longitudinally, and the accessory fibers are arranged transversely, which is conducive to maintaining the small diameter characteristic of the middle part. The bundles at both ends are locally arranged in a scattered manner, and the fiber spacing gradually increases to increase the bone contact area. The space between adjacent bundles can accommodate new fibrous tissue, providing feasibility for further tissue transformation in the body.

[0063] The specific structure of the ligament graft fixation device of this embodiment is further described below:

[0064] In this embodiment, the above-mentioned femoral end unfolding structure may specifically include a plurality of femoral end unfolding rods 4, a plurality of intermediate rods, a push ring 5, an elastic limiting member 7, and a push rod 18.

[0065] The first ends of the femoral end unfolding rods 4 are respectively surrounded and rotatably connected to the first ends of the femoral end columns 2. At least one of the above-mentioned second through holes 10 is provided on the femoral end unfolding rods 4. The push ring 5 is axially slidably connected to the femoral end column 2 along the femoral end column 2. The first ends of the intermediate rods are respectively rotatably connected to the corresponding femoral end unfolding rods 4, and the second ends of the intermediate rods are respectively rotatably connected to the push ring 5.

[0066] The elastic limiting member 7 is telescopically arranged on the femoral end column 2, and the limiting surface of the elastic limiting member 7 facing the first end surface of the femoral end column 2 is used to limit the movement of the push ring 5 in the direction of the tibial end of the pusher rod 1.

[0067] The push rod 18 is configured to extend into the bone tunnel 15 and push the push ring 5 to slide towards the first end of the femoral end column 2. Under the action of the intermediate rod, the corresponding femoral end unfolding rod 4 rotates around its connection end with the femoral end column 2, so that the second end of the femoral end unfolding rod 4 gradually moves away from the femoral end column 2. The push ring 5 is pushed and slides over the elastic limiting member 7. At this time, the push ring 5 abuts against the limiting surface, and the femoral end unfolding rod 4 unfolds and is positioned in the trapezoidal bone tunnel 15 on the femoral side 16 of the bone tunnel 15. After the unfolding is completed, the push rod 18 can exit the bone tunnel 15.

[0068] Furthermore, the femoral end column 2 is a hollow column, and a limiting notch corresponding to the elastic limiting member 7 may be provided on the side wall of the hollow column. The elastic limiting member 7 may include an elastic rod 701 and a limiting member 702. The first end of the elastic rod 701 is fixed to the inner wall surface of the hollow column, and a limiting member 702 is provided at the second end of the elastic rod 701. The limiting member 702 extends out of the limiting notch under the elastic force of the elastic rod 701. Among them, the materials of the elastic rod 701 and the limiting member 702 can both be shape memory alloys.

[0069] Specifically, the limiting member 702 may be an inverted triangle, that is, the limiting member 702 includes a limiting surface facing the first end of the femoral end column 2 and a guiding inclined surface facing the second end of the femoral end column 2. When the push ring 5 is pushed by the push rod 18, it moves upward to contact the guiding inclined surface and pushes the limiting member 702 to retract into the limiting notch against the elastic force of the elastic rod 701.

[0070] In this embodiment, in order to realize the pushing of the push ring 5, the push rod 18 may specifically include a long rod 1801 and an annular structure 1802 and a clamping structure 1803 respectively arranged at both ends of the long rod 1801.

[0071] The annular structure 1802 is provided with an avoidance notch corresponding to the elastic limiting member 7. The annular structure 1802 can be set to 180° or 270°, which can be specifically adjusted according to requirements. The setting of the avoidance notch is to prevent the limiting member 702 from not being able to extend out of the limiting notch under the action of the annular structure 1802 after the pushing ring 5 pushes past the limiting member 702; the clamping structure 1803 can be a transverse extension plate extending radially outward along the push rod 1 to facilitate clamping.

[0072] In this embodiment, the above-mentioned tibial end unfolding structure may specifically include several tibial end unfolding rods 8. The first ends of the tibial end unfolding rods 8 are respectively surrounded and rotatably connected to the first ends of the tibial end columns 3. At least one of the above-mentioned third through holes 11 is provided on the tibial end unfolding rods 8.

[0073] After the femoral end unfolding structure unfolds, the push rod 1 is disassembled and detached from the femoral end column 2, and drives the tibial end column 3 thereon to move towards the second position of the bone tunnel 15. The tibial end unfolding rods 8 rotate under the pulling action of the ligament graft 12, and the second ends of the tibial end unfolding rods 4 gradually move away from the tibial end column 3 and are positioned at the second position of the bone tunnel 15. After the tibial end unfolding structure unfolds, the push rod 1 is disassembled and detached from the tibial end column 3 and exits the bone tunnel 15.

[0074] In this embodiment, in order to enhance the fixing effect with the bone tunnel 15, barbed tooth-like structures are provided at the second ends of the femoral end unfolding rod 4 and the tibial end unfolding rod 8, so as to increase the friction between the unfolding rod and the bone surface.

[0075] In this embodiment, along the first end to the second end of the femoral end unfolding rod 4, a plurality of second through holes 10 are evenly distributed on the femoral end unfolding rod 4. Along the first end to the second end of the tibial end unfolding rod 8, a plurality of third through holes 11 are evenly distributed on the tibial end unfolding rod 8. That is, a plurality of corresponding through holes can be arranged along the length direction of each unfolding rod, and the specific number can be determined according to the amount of fiber beam splitting required, and no specific limitation is made here.

[0076] In this embodiment, annular extension structures are formed on the first ends of the femoral end column 2 and the tibial end column 3 by extending radially outward along their circumferences. A plurality of first connection notches are arranged at intervals along the circumferential direction on the annular extension structure, and first rotating shafts are provided in the first connection notches.

[0077] The first ends of the femoral end unfolding rod 4 and the tibial end unfolding rod 8 respectively extend into the first connection notches of the corresponding annular extension structures and are rotatably connected to the corresponding first rotating shafts, so as to realize the rotational connection between the femoral end unfolding rod 4 and the femoral end column 2.

[0078] Further, in order to achieve stable rotation of the femoral end deployment rod 4, the intermediate rod may include two side rods 6 corresponding to the femoral end deployment rod 4. A plurality of second connection notches are arranged at intervals along the circumferential direction on the pushing ring 5, and a second rotating shaft is provided in the second connection notch. The femoral end deployment rod 4 is provided with third rotating shafts protruding from both sides thereof. The first end of the side rod 6 extends into the corresponding second connection notch and is rotatably connected to the second rotating shaft, and the second end of the side rod 6 is rotatably connected to the corresponding side of the third rotating shaft, thereby realizing an unfolding structure similar to an umbrella.

[0079] In this embodiment, the detachable connection method can be set as a threaded connection, that is, the above-mentioned push rod 1 can specifically be a threaded rod, and corresponding threaded holes are respectively provided on the femoral end column 2 and the tibial end column 3, and are respectively threadedly connected to the threaded rod.

[0080] See Figure 9 , the following will expand and illustrate the usage steps of the ligament graft fixation device in this embodiment during ACL reconstruction:

[0081] ① First, create smaller-diameter bone tunnels 15 on the femoral side 16 and the tibial side 17 in the manner of passing through the tibial tunnel (based on the width of the push rod 1 that can pass through);

[0082] ② Then use reaming instruments to create bone tunnels 15 with a trapezoidal cross-section on both sides, where the cross-sectional area of the tunnel opening near the joint surface refers to the area of the native ACL bone attachment point;

[0083] ③ Insert the ligament graft fixation device through the medial parapatellar approach. First, push the femoral end column 2 and the femoral end unfolding structure into the femoral tunnel 15, and then push the tibial end column 3 and the tibial end unfolding structure into the tibial tunnel 15, and adjust the position of the fixation device in the bone tunnel 15;

[0084] ④ Insert the push rod 18 through the medial parapatellar approach. One hand pulls the push rod 1 from the tibial side 17, and the other hand pushes the push rod 18 towards the femoral side 16 until the femoral end deployment column is unfolded and the pushing ring 5 is caught by the limiting member 702;

[0085] ⑤ Remove the push rod 18 and close the medial parapatellar incision;

[0086] ⑥ Unscrew the push rod 1 until it is separated from the thread of the femoral end column 2, and pull the push rod 1 downward along the tibial bone tunnel 15 until the tibial end deployment column is opened under the traction of the ligament graft 12;

[0087] ⑦ Continue to pull the push rod 1 downward along the tibial tunnel 15 to generate appropriate prestress on the ligament graft, unscrew the push rod 1 until it is separated from the thread of the tibial end column 3, and fix the ligament graft 12 at the distal end of the tibial side 17 to the cortical bone at the tunnel opening through a button titanium plate.

[0088] Thus, the reconstruction surgery is completed. This implantation step can achieve the implantation and fixation of the umbrella-shaped ligament graft through minimally invasive surgery, and is expected to improve the current complications such as abnormal joint kinematics, early cartilage wear, bone tunnel enlargement, and graft rupture after ACL reconstruction.

[0089] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, provided that these changes fall within the scope of the claims of the present invention and its equivalent technologies, they still fall within the protection scope of the present invention.

Claims

1. A ligament graft fixation device, characterized in that, Comprising: A push rod, a femoral end column is detachably connected to the femoral end of the push rod, a first through hole is formed in the tibial end of the push rod, and a tibial end column is detachably connected to the push rod; A femoral end deployment structure, a fixed end of the femoral end deployment structure is mounted on a first end of the femoral end column, and a deployment end of the femoral end deployment structure is configured to deploy radially outwardly towards the push rod; and, at least one second through hole is provided on the deployment end of the femoral end deployment structure; A tibial end deployment structure, a fixed end of the tibial end deployment structure is mounted on the tibial end column, and a deployment end of the tibial end deployment structure is configured to deploy radially outwardly towards the push rod; and, at least one third through hole is provided on the deployment end of the tibial end deployment structure; The femoral end and the tibial end of the graft are respectively configured as at least one first split bundle and at least one second split bundle, the first split bundle is configured to pass through the corresponding second through hole and form a first closed loop with the graft, and the second split bundle is configured to sequentially pass through the corresponding first through hole and the third through hole to form a second closed loop; After the push rod and the femoral end deployment structure and the tibial end deployment structure thereon are configured for the target object, the femoral end deployment structure and the first split bundle deploy radially outwardly and fit to a first position of the target object, the femoral end of the push rod exits the femoral end column, the tibial end deployment structure and the second split bundle deploy radially outwardly and fit to a second position of the target object. After the deployment is completed, the tibial end of the graft is fixed to the target object, the relative positions of the femoral end deployment structure and the tibial end deployment structure and the target object are fixed, and the push rod exits the target object; The femoral end deployment structure includes a plurality of femoral end deployment rods, a plurality of intermediate rods, a push ring, an elastic limiting member and a push rod; The first ends of the femoral end deployment rods respectively surround and are rotatably connected to the first end of the femoral end column; at least one of the second through holes is provided on the femoral end deployment rods; The push ring is slidably connected to the femoral end column along the axial direction of the femoral end column; The first ends of the intermediate rods are respectively rotatably connected to the corresponding femoral end deployment rods, and the second ends of the intermediate rods are respectively rotatably connected to the push ring; The elastic limiting member is telescopically arranged on the femoral end column, and the limiting surface of the elastic limiting member facing the first end surface of the femoral end column; The push rod is configured to extend into the target object and push the push ring to slide towards the first end of the femoral end column. Under the action of the intermediate rod, the corresponding femoral end deployment rod rotates, and the second end of the femoral end deployment rod gradually moves away from the femoral end column. The push ring slides over the elastic limiting member and abuts against the limiting surface, and the femoral end deployment rod deploys and is positioned at the first position of the target object; After the deployment is completed, the push rod exits the target object.

2. The ligament graft fixation device according to claim 1, characterized in that, The femoral end column is a hollow column, and a limiting notch corresponding to the elastic limiting member is formed on the side wall of the hollow column; The elastic limiting member includes an elastic rod and a limiting member; the first end of the elastic rod is fixed on the inner wall surface of the hollow column, the second end of the elastic rod is provided with the limiting member, and the limiting member extends out of the limiting notch under the elastic force of the elastic rod. The limiting member includes the limiting surface facing the first end of the femoral end column and the guiding inclined surface facing the second end of the femoral end column; the pushing ring moves into contact with the guiding inclined surface and pushes the limiting member to retract into the limiting notch against the elastic force of the elastic rod.

3. The ligament graft fixation device according to claim 1, characterized in that, The push rod includes a long rod and an annular structure and a clamping structure respectively arranged at both ends of the long rod. The annular structure is provided with an avoidance notch corresponding to the elastic limiting member, and the clamping structure is a transverse extension plate extending radially outward along the push rod.

4. The ligament graft fixation device according to claim 1, wherein The tibial end unfolding structure includes a plurality of tibial end unfolding rods. The first ends of the tibial end unfolding rods are respectively surrounded and rotatably connected to the first end of the tibial end column; at least one of the third through holes is provided on the tibial end unfolding rod. After the femoral end unfolding structure unfolds, the push rod is disassembled and separated from the femoral end column, and drives the tibial end column thereon to move towards the second position of the target object. The tibial end unfolding rod rotates under the pulling action of the graft, and the second end of the tibial end unfolding rod gradually moves away from the tibial end column and is positioned at the second position of the target object; after the tibial end unfolding structure unfolds, the push rod is disassembled and separated from the tibial end column and exits the target object.

5. The ligament graft fixation device according to claim 4, wherein Barbed tooth-like structures are provided on the second ends of both the femoral end unfolding rod and the tibial end unfolding rod.

6. The ligament graft fixation device according to claim 5, characterized in that, Along the first end to the second end of the femoral end unfolding rod, a plurality of the second through holes are respectively evenly distributed on the femoral end unfolding rod. Along the first end to the second end of the tibial end unfolding rod, a plurality of the third through holes are respectively evenly distributed on the tibial end unfolding rod.

7. The ligament graft fixation device according to claim 4, characterized in that, An annular extension structure is formed by radially outward extension on the first ends of both the femoral end column and the tibial end column; a plurality of first connection notches are arranged at intervals along the circumferential direction on the annular extension structure, and a first rotating shaft is arranged in the first connection notch. The first ends of the femoral end unfolding rod and the tibial end unfolding rod respectively extend into the first connection notches of the corresponding annular extension structures and are rotatably connected to the corresponding first rotating shafts.

8. The ligament graft fixation device according to claim 1, characterized in that The intermediate rod includes two side rods corresponding to the femoral end unfolding rod. A plurality of second connection notches are arranged at intervals along the circumferential direction on the pushing ring, and a second rotating shaft is arranged in the second connection notch. Third rotating shafts extending out of both sides of the femoral end unfolding rod are provided on the femoral end unfolding rod. The first end of the side rod extends into the corresponding second connection notch and is rotatably connected to the second rotating shaft; the second end of the side rod is rotatably connected to the corresponding side of the third rotating shaft.

9. The ligament graft fixation device according to claim 1, characterized in that, The push rod is a threaded rod; corresponding threaded holes are respectively provided on the femoral end column and the tibial end column and are respectively threadedly connected to the threaded rod.

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