A structure of bone-patellar tendon-bone graft and preparation method thereof

Abstract

The present invention relates to a structure of a bone-patellar tendon-bone graft and a preparation method thereof, comprising a patellar cylinder, a patellar ligament, a tibial cylinder and a cone, wherein the patellar cylinder and the tibial cylinder are both connected at two ends of the patellar ligament by natural biological tissue, the cone is formed by grinding one end of the patellar cylinder and the tibial cylinder, wherein the tips of the two cones are oriented in the same direction; a circular hole with a diameter of 2 mm is respectively opened at one-third of the boundary of each of the patellar cylinder and the tibial cylinder, the circular hole passes through the patellar cylinder and the tibial cylinder, and a No. 2 polymer non-absorbable braided wire is passed through the circular hole. The present invention has the advantage of realizing reliable and effective transplantation and repair after rupture of ligaments such as the cruciate ligament of the knee joint.

Description

Technical Field

[0001] The present invention relates to the technical field of transplantation surgery, and in particular to a structure of a bone-patellar tendon-bone transplant and a preparation method thereof. Background Art

[0002] The cruciate ligament of the knee joint is an important stabilizing structure of the knee joint. It is hingedly connected between the intercondylar fossa of the femur and the intercondylar eminence of the tibia, which can prevent the tibia from shifting forward and backward along the femur. The cruciate ligament of the knee can be divided into two, the anterior cruciate ligament, which starts from the medial side of the lateral condyle of the femur, obliquely moves forward and downward, and ends at the front part of the intercondylar eminence of the tibia and the anterior corners of the medial and lateral menisci; the posterior cruciate ligament starts from the lateral side of the medial condyle of the femur, obliquely moves backward and downward, and ends at the rear part of the intercondylar eminence of the tibia and the posterior corner of the lateral meniscus. When the knee joint moves, part of the fibers of each of the two ligaments are in a tense state. Therefore, in addition to the anterior cruciate ligament preventing the tibia from shifting forward and the posterior cruciate ligament preventing the leg bones from shifting backward, they can also limit the hyperextension, hyperflexion and rotation of the knee joint. Cruciate ligament injury often occurs at the same time as tibial collateral ligament or meniscus injury.

[0003] There are almost no blood vessels in the knee joint ligaments. The nutrients are supplied by the synovial fluid in the joint capsule and the capillary network attached to the surface of the ligaments. Therefore, it is difficult for the ligament to heal itself after it is broken. Ligament rupture for more than 6 weeks is considered an old injury. At this time, most ligaments have usually been dissolved and absorbed in the synovial fluid. Therefore, after the cruciate ligament of the knee is injured, ligament reconstruction surgery is usually required to restore its function. The repair materials are mostly autologous tendons, allogeneic tendons, and artificial ligaments. Autologous tendons often leave pain at the tendon removal site after surgery, and there will also be a certain loss of strength in the lower limbs. Artificial ligaments are due to rejection reactions and high prices.

[0004] Therefore, in view of the above shortcomings, it is necessary to provide a structure of a bone-patellar tendon-bone graft and a preparation method thereof. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The technical problem to be solved by the present invention is to solve the problem that the anterior and posterior cruciate ligaments transplanted with autologous tendons have rejection reactions and are expensive.

[0007] (II) Technical solution

[0008] In order to solve the above technical problems, the present invention provides a bone-patellar tendon-bone graft structure, including a patellar cylinder, a patellar ligament, a tibial cylinder and a cone. The patellar cylinder and the tibial cylinder are connected at both ends of the patellar ligament by natural biological tissue. The cone is formed by grinding one end of the patellar cylinder and the tibial cylinder, wherein the tips of the two cones are oriented in the same direction; a circular hole with a diameter of 2 mm is opened at the one-third boundary of each of the patellar cylinder and the tibial cylinder, respectively, and the circular hole passes through the patellar cylinder and the tibial cylinder, and a No. 2 polymer non-absorbable braided wire is passed through the circular hole.

[0009] As a further illustration of the present invention, preferably, bone tunnels are opened in the patient's tibia and femur, and the cylindrical patella cylinder and its cone are pulled by No. 2 polymer non-absorbable braided wire and inserted into the patient's tibial bone tunnel or femoral bone tunnel; the tibial cylinder and its cone are pulled by No. 2 polymer non-absorbable braided wire and inserted into the patient's femoral bone tunnel or tibial bone tunnel.

[0010] As a further illustration of the present invention, preferably, the bone tunnel is a circular anterior-posterior perforation with a diameter of 2 mm.

[0011] As a further illustration of the present invention, preferably, the patellar cylinder and its cone and the tibial cylinder and its cone for transplantation are 10mm to 70mm in length and 8mm to 20mm in diameter, the patellar ligament is 30mm to 75mm in length, 5mm to 25mm in width and 1mm to 5mm in thickness.

[0012] The present invention also provides a method for preparing a bone-patellar tendon-bone graft, comprising the following steps:

[0013] Ⅰ. The patella, patellar ligament and part of the tibia are completely removed from the donor. The patellar ligament is connected to the patella and part of the tibia at both ends through the natural structure. The patella, patellar ligament and part of the tibia are divided into two parts along the midline;

[0014] Ⅱ. Grinding each half of the patellar bone block into a patellar cylinder and a cone thereof, and grinding each half of the tibia bone block into a tibia cylinder and a cone thereof, so as to achieve the effect of making two bone-patellar tendon-bone grafts;

[0015] III. Drill a 2mm diameter hole on each patellar cylinder and tibial cylinder at the one-third dividing line. The hole should be perpendicular to the surface of the cylinder and penetrate the front and back.

[0016] IV. Insert No. 2 polymer non-absorbable braided wire into each circular hole to pull the patellar cylinder and its cone and the tibial cylinder and its cone to the required position.

[0017] As a further illustration of the present invention, preferably, the patellar cylinder, patellar ligament and tibial cylinder for transplantation need to be taken from healthy donors aged 18 to 45 years old within 12 hours of death.

[0018] As a further illustration of the present invention, preferably, the patellar cylinder and tibial cylinder for transplantation should be white or slightly yellow with a reddish color in a healthy state, the patellar ligament should be white or slightly yellow, the cancellous bone trabecula structure should be clear, and the cortical bone surface should be smooth.

[0019] As a further illustration of the present invention, preferably, the maximum load of the patellar cylinder, patellar ligament and tibial cylinder for transplantation is greater than 1500N.

[0020] As a further illustration of the present invention, preferably, the patellar cylinder, patellar ligament and tibial cylinder for transplantation need to be tested for cytotoxicity, genotoxicity, sensitization, pyrogen and hemolysis before transplantation.

[0021] (III) Beneficial effects

[0022] The above technical solution of the present invention has the following advantages:

[0023] The present invention relies on a reliable source of grafts, and the bone structure of the graft is trimmed, which greatly increases the convenience, stability and anatomical fixation of fixation. It has reasonable anatomical structure and convenient operation, can be applied to knee joints with ruptured cruciate ligaments, and is suitable for clinical promotion and application in orthopedics. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a knee joint skeleton diagram of the present invention;

[0025] Figure 2 It is a structural diagram of the patellar cylinder, patellar ligament and tibial cylinder for transplantation of the present invention;

[0026] Figure 3 It is a threading path diagram of the No. 2 non-absorbable braided wire for transplantation of the present invention;

[0027] Figure 4 It is a transplantation state diagram of the present invention.

[0028] In the figure: 1. Patellar cylinder; 2. Patellar ligament; 21. Medullary canal; 3. Tibial cylinder; 4. Cone; 5. Round hole; 6. No. 2 non-absorbable braided wire; 7. Femur; 8. Patella; 9. Tibia. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] A bone-patellar tendon-bone graft structure, combined with Figure 2 , Figure 3 , including a patellar cylinder 1, a patellar ligament 2, a tibial cylinder 3 and a cone 4. The patellar cylinder 1 and the tibial cylinder 3 are connected at both ends of the patellar ligament 2 by natural biological tissues. Figure 1 The patella cylinder 1 and the tibial cylinder 3 used for transplantation are preferably made of irregular cut pieces (dashed line part) taken from the patella 8 and the tibia 9 of the transplanted body and polished into cylinders, and the cone 4 is formed by polishing one end of the patella cylinder 1 and the tibial cylinder 3, wherein the tips of the two cones 4 are in the same direction; Figure 4 The femur 7 and tibia 9 of the patient are both provided with bone tunnels 21 on the curved surface of the joint cavity, and the bone tunnels 21 are circular anterior-posterior through holes with a diameter of 2 mm; the cylindrical patella cylinder 1 and the tibial cylinder 3 are both inserted into the bone tunnel 21, and the cylindrical patella cylinder 1 and the tibial cylinder 3 are inserted into the patient's tibia 9 or femur 7 to simulate the physiological state of the anterior and posterior cruciate ligaments, so that the transplanted patellar ligament 2 can almost perfectly replace the damaged anterior and posterior cruciate ligaments, ensuring that the patient's knee joint can perform normal physiological work after transplantation.

[0031] Combination Figure 3 , Figure 4 A circular hole 5 with a diameter of 2 mm is opened at the one-third boundary of each of the patella cylinder 1 and the tibial cylinder 3, and the circular hole 5 passes through the patella cylinder 1 and the tibial cylinder 3, and a No. 2 polymer non-absorbable braided wire 6 is inserted into the circular hole 5; the cylindrical patella cylinder 1 and its cone 4 are pulled by the No. 2 polymer non-absorbable braided wire 6 and inserted into the patient's tibial bone tunnel 21 or femoral bone tunnel 22; the tibial cylinder 3 and its cone 4 are pulled by the No. 2 polymer non-absorbable braided wire 6 and inserted into the patient's femoral bone tunnel 21 or tibial bone tunnel 21, wherein the cones 4 are all facing the medullary canal 21, so as to reduce the resistance of the patella cylinder 1 and the tibial cylinder 3 to the femur 7 and the tibia 9 during traction.

[0032] The bone tunnel 21 is provided to facilitate the transplantation of the cylindrical patella cylinder 1 and the tibial cylinder 3 to the affected area, thus achieving a simple transplantation process.

[0033] Combination Figure 2 , Figure 3The patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 for transplantation must be taken from healthy donors aged 18 to 45 years old within 12 hours of death to ensure that the patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 for transplantation have excellent physiological structure and can perform physiological work for a long time after transplantation; the patellar cylinder 1 and tibial cylinder 3 for transplantation should be white or slightly yellow with a reddish healthy state, the patellar ligament 2 should be white or slightly yellow with a clear cancellous bone trabecular structure and a smooth cortical bone surface to ensure that the patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 to be transplanted are healthy and free of loss or disease, thus avoiding secondary injury to the patient; the maximum load of the patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 used for transplantation is greater than 1500N, so that the transplanted patellar ligament 2 can excellently replace the original anterior and posterior cruciate ligaments, further ensuring that the patient's knee joint can perform normal physiological work; the patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 used for transplantation must undergo cytotoxicity, genetic toxicity, sensitization, pyrogen and hemolysis tests before transplantation, so that the patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 used for transplantation have extremely high safety, thus avoiding rejection by the patient. The patellar cylinder 1 and tibial cylinder 3 used for transplantation are 15mm to 70mm in length and 8mm to 12mm in diameter. The patellar ligament 2 is 30mm to 75mm in length, 5mm to 25mm in width and 1mm to 5mm in thickness. They can be directly selected during surgery to reduce the risk of unstable fixation and improve the adaptability of the transplant.

[0034] In some embodiments of the present invention, the patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 for knee joint transplantation can also be made of tissue engineering materials, including natural biomaterials and artificial synthetic biomaterials, such as polyvinyl alcohol-hydrogel (PVA-H), gelatin sponge, collagen, alginate, polyglycolic acid (PGA), polylactic acid (PLA), fibrin gel, etc. For example, in one embodiment of the present invention, the patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 can be made of 3D printed polylactic acid-polycaprolactone copolymer P (LLA-CL) scaffold material. The patellar cylinder 1, patellar ligament 2 and tibial cylinder 3 implants for knee joint transplantation can also be further subjected to in vitro cell culture on the above-mentioned tissue engineering scaffold material to obtain corresponding bionic tissues; the use of artificially produced substitutes can avoid rejection reactions in patients.

[0035] The present invention also provides a method for preparing and transplanting a bone-patellar tendon-bone graft, comprising the following steps:

[0036] Ⅰ. The patella 8, patellar ligament 2 and part of the tibia 9 are completely removed from the donor, the patellar ligament 2 is connected to the patella 8 and part of the tibia 9 at both ends through the natural structure, and the patella 8, patellar ligament 2 and part of the tibia 9 are divided into two parts along the midline;

[0037] Ⅱ. Each half of the patella 8 is ground into a patellar cylinder 1 and a cone 4, and each half of the tibia 9 is ground into a tibial cylinder 3 and a cone 4, so as to achieve the effect of making two bone-patellar tendon-bone grafts;

[0038] III. Drill a 2mm diameter hole 5 on each patella cylinder 1 and tibial cylinder 3 at the one-third dividing line. The hole 5 is perpendicular to the surface of the cylinder and penetrates the front and back;

[0039] IV. A second polymer non-absorbable braided wire 6 is inserted into each circular hole 5 to pull the patellar cylinder 1 and its cone 4 and the tibial cylinder 3 and its cone 4 to the desired position;

[0040] VI. Use a hollow drill to drill a bone tunnel 21 in the femur 7 and tibia 9 of the patient's knee joint, and insert the polished patella cylinder 1 and its cone 4 and the tibial cylinder 3 and its cone 4 into the bone tunnels 21 of the patient's tibia 7 and femur 9 respectively for fixation, wherein a through hole is also required to be opened in the femur 7, and the No. 2 polymer non-absorbable braided wire 6 on the patella cylinder 1 passes through the femur 7 through the through hole, so as to pull the patella cylinder 1 and its cone 4 into the medullary canal 21 of the femur 7.

[0041] The present invention utilizes reasonable structural anatomy to reconstruct knee ligaments using a processed cylindrical bone graft with a cone 4 and a round hole 5, which makes the operation faster and simpler without reducing the firmness of fixation, thereby achieving reliable and effective transplantation repair after a rupture of the cruciate ligament of the knee. The present invention is applicable to knee joints with a rupture of the cruciate ligament and is suitable for clinical promotion and application in orthopedics.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bone-patellar tendon-bone graft structure, characterized in that: The invention comprises a patellar cylinder (1), a patellar ligament (2), a tibial cylinder (3) and a cone (4). The patellar cylinder (1) and the tibial cylinder (3) are connected to the two ends of the patellar ligament (2) by natural biological tissue. The cone (4) is formed by grinding one end of the patellar cylinder (1) and the tibial cylinder (3), wherein the tips of the two cones (4) are oriented in the same direction. A circular hole (5) with a diameter of 2 mm is respectively opened at the one-third boundary of each of the patellar cylinder (1) and the tibial cylinder (3). The circular hole (5) passes through the patellar cylinder (1) and the tibial cylinder (3), and a No. 2 polymer non-absorbable braided wire (6) is inserted into the circular hole (5).

2. The bone-patellar tendon-bone graft structure according to claim 1, characterized in that: Bone tunnels (21) are opened in the patient's tibia and femur. The cylindrical patellar cylinder (1) and its cone (4) are pulled by a No. 2 polymer non-absorbable braided wire (6) and inserted into the patient's tibial bone tunnel (21) or femoral bone tunnel (21); the tibial cylinder (3) and its cone (4) are pulled by a No. 2 polymer non-absorbable braided wire (6) and inserted into the patient's femoral bone tunnel (21) or tibial bone tunnel (21).

3. The bone-patellar tendon-bone graft structure according to claim 2, characterized in that: The bone tunnel (21) is a circular anterior-posterior perforation with a diameter of 2 mm.

4. The bone-patellar tendon-bone graft structure according to claim 1, characterized in that: The patellar cylinder (1) and its cone (4) and the tibial cylinder (3) and its cone (4) for transplantation are 10 mm to 70 mm in length and 8 mm to 20 mm in diameter. The patellar ligament (2) is 30 mm to 75 mm in length, 5 mm to 25 mm in width and 1 mm to 5 mm in thickness.

5. A method for preparing a bone-patellar tendon-bone graft, characterized in that: The following steps are included: Ⅰ. The patella (8), patellar ligament (2) and part of the tibia (9) are completely removed from the donor. The patellar ligament (2) is connected to the patella (8) and part of the tibia (9) at both ends through the natural structure. The patella (8), patellar ligament (2) and part of the tibia (9) are divided into two parts along the midline of the patella (8), patellar ligament (2) and part of the tibia (9); Ⅱ. Grinding each half of the patella (8) into a patellar cylinder (1) and a cone (4) thereof, and grinding each half of the tibia (9) into a tibial cylinder (3) and a cone (4) thereof, so as to achieve the effect of making two bone-patellar tendon-bone grafts; III. Drill a 2 mm diameter circular hole (5) on each patellar cylinder (1) and tibial cylinder (3) at the one-third dividing line, with the circular hole (5) being perpendicular to the surface of the cylinder and penetrating the front and back; IV. Inserting a second-grade polymer non-absorbable braided wire (6) into each circular hole (5) to pull the patellar cylinder (1) and its cone (4) and the tibial cylinder (1) and its cone (4) to the desired position; The patellar cylinder (1), patellar ligament (2) and tibial cylinder (3) used for transplantation need to be taken from healthy donors aged 18 to 45 years within 12 hours of death or artificially made vinyl alcohol-hydrogel.

6. The method for preparing a bone-patellar tendon-bone graft according to claim 5, characterized in that: The patellar cylinder (1) and tibial cylinder (3) used for transplantation should be white or slightly yellow with a reddish color in a healthy state, the patellar ligament (2) should be white or slightly yellow, the cancellous bone trabecula structure should be clear, and the cortical bone surface should be smooth.

7. The method for preparing a bone-patellar tendon-bone graft according to claim 5, characterized in that: The maximum load of the patellar cylinder (1), patellar ligament (2) and tibial cylinder (3) for transplantation is greater than 1500N.

8. The method for preparing a bone-patellar tendon-bone graft according to claim 5, characterized in that: The patellar cylinder (1), patellar ligament (2) and tibial cylinder (3) for transplantation must undergo cytotoxicity, genotoxicity, sensitization, pyrogen and hemolysis tests before transplantation.

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