阅读说明：本技术 一种用于固定骨瓣的可吸收颅骨锁及其制作方法 (Absorbable skull lock for fixing bone flap and manufacturing method thereof ) 是由 刘平 张乃保 葛振清 钦湘 薛云琴 万晶 于 2021-06-28 设计创作，主要内容包括：本发明公开了一种用于固定骨瓣的可吸收颅骨锁,其特征在于,包括下压片,所述下压片的一端面中部一体制出一螺杆,所述螺杆远离所述下压片的一端固定有手柄,所述螺杆外缘套装有一上压片,所述上压片相对所述下压片的一端面设有固定齿,所述上压片具有内螺纹,所述螺杆具有外螺纹,所述内螺纹的内径与所述螺杆的外径相匹配,使得所述上压片能够配合在所述螺杆上并相对于所述螺杆通过螺纹移动。本发明还公开了其制作方法。本发明的颅骨锁采用可吸收材质(丙交酯/乙交酯共聚物)制成,对于成人和儿童患者均适用,有助于术后病灶部位的复查,尤其有利于手术后需要继续接受放疗的患者。(The invention discloses an absorbable skull lock for fixing bone flaps, which is characterized by comprising a lower pressing sheet, wherein a screw is integrally manufactured in the middle of one end face of the lower pressing sheet, a handle is fixed at one end of the screw, which is far away from the lower pressing sheet, an upper pressing sheet is sleeved on the outer edge of the screw, a fixed tooth is arranged on one end face of the upper pressing sheet, which is opposite to the lower pressing sheet, the upper pressing sheet is provided with an internal thread, the screw is provided with an external thread, and the internal diameter of the internal thread is matched with the external diameter of the screw, so that the upper pressing sheet can be matched on the screw and move relative to the screw through the threads. The invention also discloses a manufacturing method of the composite material. The skull lock is made of absorbable materials (lactide/glycolide copolymers), is suitable for both adult patients and child patients, is favorable for the reexamination of postoperative focus positions, and is particularly favorable for patients who need to continue to receive radiotherapy after an operation.)

1. The absorbable skull lock for fixing the bone flap is characterized by comprising a lower pressing plate, wherein a screw is integrally manufactured in the middle of one end face of the lower pressing plate, a handle is fixed at one end, far away from the lower pressing plate, of the screw, an upper pressing plate is sleeved on the outer edge of the screw, fixing teeth are arranged on one end face, opposite to the lower pressing plate, of the upper pressing plate, the upper pressing plate is provided with internal threads, the screw is provided with external threads, and the internal diameter of the internal threads is matched with the external diameter of the screw, so that the upper pressing plate can be matched with the screw and can move relative to the screw through threads.

2. The absorbable skull lock for fixation of bone flap of claim 1, wherein the lower compression plate, the screw and the upper compression plate are all made of absorbable L-lactide/glycolide copolymer (PLGA) material; the handle is made of Polycarbonate (PC) material.

3. The absorbable skull lock of claim 1, wherein the lower and upper tabs are each circular.

4. The absorbable skull lock of claim 1, wherein the lower compression tab and the upper compression tab have a diameter of 14 mm; the total length of the skull lock is 56 mm.

5. A method of making an absorbable skull lock for fixation of bone flaps, the method comprising the steps of:

pretreatment: taking out absorbable L-lactide/glycolide copolymer material from a low-temperature environment (-15 ℃), placing the L-lactide/glycolide copolymer material until the L-lactide/glycolide copolymer material is recovered to room temperature, and opening the package;

and (3) drying: drying the raw materials before melting;

and (3) melting and injection molding: adding the dried raw materials into a single-screw extruder for melt injection molding;

and (3) post-treatment: and carrying out injection molding post-treatment by means of oriented stretching and heat treatment.

6. The method of claim 5, wherein the drying method comprises vacuum drying at 40-80 ℃ for 4-6 hours under low vacuum or drying with a drying agent having a dew point of-40 ℃ to-50 ℃.

7. The method of manufacturing of claim 5, wherein the melt injection molding conditions are: the temperature of a machine barrel is 180-215 ℃, the temperature of a die is 65-80 ℃, the injection pressure is 90-100 MPa, and the injection speed is 55-70 cm³The residence time of the melt is 10 to 20min。

8. The method according to claim 5, wherein the stretching temperature is 75 to 95 ℃ and the heat treatment temperature is 95 to 105 ℃.

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to an absorbable skull lock for fixing bone flaps and a manufacturing method thereof.

Background

The skull flap reduction after the craniotomy is the basic operation of neurosurgery, the free flap is reduced and fixed, so that the integrity of the skull is reconstructed to the maximum extent, the balance and stability of intracranial pressure are kept, brain tissues are protected, and the second-stage skull repairing operation is avoided. When the free bone flap is reset, the free bone flap needs to be fixed on the peripheral skull by means of instruments, so that the bone flap is prevented from moving or beating along with brain tissue.

The existing skull lock made of titanium alloy material has wide clinical application, but the main defect is that the clinical application range is limited to adults. For a child patient, the skull is still in a growth and development stage, the thin titanium nail of the skull is easy to penetrate through the inner plate, or the skull is thin due to gradual absorption of the inner plate in the skull development process, the fixed screw is likely to shift to the deep part, the tip of the fixed screw can pierce the dura mater and even be inserted into the brain tissue, the tension stress embedded between the screws at two ends of the skull bone acts continuously for a long time, the development of the skull can be limited, and the development of the brain tissue is further influenced. In addition, titanium alloy materials are susceptible to interference in imaging examinations (CT, MRI, and X-ray), which affects diagnostic accuracy. The skull lock made of non-absorbable plastics (PEEK, POM and PP) overcomes most of the defects of the titanium alloy skull lock, but the permanent retention condition in the body after operation can not be changed.

For example, chinese utility model patent No. CN201720317482.2 discloses a degradable skull lock for improving skull healing ability, wherein the locking plate of the skull lock is made of degradable bioceramic/pure magnesium or magnesium alloy/bioceramic composite material with "sandwich" structure, and has the feature of complete absorption in vivo. When the composite material with the sandwich structure is degraded, magnesium ions and calcium ions with the effect of promoting bone healing can be slowly released, so that the phenomena of bone dissolution and gas accumulation caused by too fast degradation of pure magnesium or magnesium alloy can be avoided, healing between a bone flap and a skull can be effectively promoted, and the composite material also has excellent mechanical property and can play a strong role in fixation; the skull lock is provided with functional wires made of magnesium or magnesium alloy wires, is filled in gaps between skull bone flaps and the skull, and guides bone tissues and blood vessels to grow in by utilizing the bone induction performance of magnesium, so that the healing of the bone flaps and the skull is promoted.

For another example, the chinese utility model patent with application number CN201521141161.9 discloses a skull lock with firm fixation, wherein the central shaft is an i-shaped thin plate, the side edges at both sides of the central shaft increase the structural rigidity of the central shaft and the stability of the installation of the upper locking plate, the inverted teeth made on the end surfaces of the two recesses between the two side edges are matched with the fixed teeth made on the inner edge through holes of the upper locking plate, which can facilitate the quick installation of the upper locking plate and the central shaft, the inverted teeth are matched with the fixed teeth to increase the firmness of the installation of the upper locking plate and prevent the upper locking plate from falling off, the skull fixed teeth made on the end surfaces of the upper locking plate and the lower locking plate which are arranged oppositely can be in the skull lock fixation state, so that the skull fixed teeth are in close contact with the inner and outer end surfaces of the skull, thereby increasing the friction force of the upper locking plate and the lower locking plate in the skull tangential direction, and avoiding the dislocation and deviation in the tangential direction of the skull after the skull lock is fixed; the skull fixing teeth are tetrahedron, so that the structural strength of the skull fixing teeth is increased, and the skull fixing teeth are prevented from being deformed and bent; the PPDO material has excellent hydrophilicity and softness, and improves the compatibility with skin and tissues.

The magnesium alloy used as a degradable material has the problems of easy corrosion and high degradation rate, and the high degradation rate can cause the implanted material to be seriously corroded before the organism is not healed, thereby reducing the mechanical property and the stability of the material. In addition, the rapid corrosion of magnesium alloys is accompanied by a large release of hydrogen, which has no time to diffuse and absorb to form bubbles around the implant, affecting the physiological function of the surrounding tissues and restoring the therapy. Too rapid a degradation rate will increase the local pH of the body fluid in the vicinity of the implant, potentially damaging the bone and tissue growth of the body, for example, leading to protein deposition and inflammation in the body tissue, or hemolysis and local osteolysis.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an absorbable skull lock for fixing bone flaps and a manufacturing method thereof. The absorbable skull lock is made of an absorbable material, namely lactide/glycolide copolymer (PLGA), is suitable for both adult and child patients, can reduce the possibility of bone growth inhibition, implant displacement, implant touch, temperature-sensitive reaction and the like caused by the skull lock after operation, does not influence the effect of postoperative imaging (CT, MRI and X-ray), is favorable for the reexamination of postoperative focus parts, and is particularly favorable for patients needing to continue to receive radiotherapy after the operation.

The technical purpose of the invention is realized by the following technical scheme:

one aspect of the invention provides an absorbable skull lock for fixing bone flaps, which is characterized by comprising a lower pressing sheet, wherein a screw is integrally formed in the middle of one end face of the lower pressing sheet, a handle is fixed at one end of the screw, which is far away from the lower pressing sheet, an upper pressing sheet is sleeved on the outer edge of the screw, a fixed tooth is arranged on one end face of the upper pressing sheet, which is opposite to the lower pressing sheet, the upper pressing sheet is provided with an internal thread, the screw is provided with an external thread, and the internal diameter of the internal thread is matched with the external diameter of the screw, so that the upper pressing sheet can be matched on the screw and move relative to the screw through the threads.

Preferably, the lower pressing sheet, the screw and the upper pressing sheet are all made of absorbable L-lactide/glycolide copolymer (PLGA) materials; the handle is made of Polycarbonate (PC) material.

Preferably, the lower pressing plate and the upper pressing plate are both circular.

Preferably, the diameter of the lower pressing sheet and the upper pressing sheet is phi 14 mm; the total length of the skull lock is 56 mm.

The technical purpose of the invention is also realized by the following technical scheme:

another aspect of the present invention provides a method of making an absorbable skull lock for fixation of bone flaps, the method comprising the steps of:

pretreatment: taking out absorbable L-lactide/glycolide copolymer material from a low-temperature environment (-15 ℃), placing the L-lactide/glycolide copolymer material until the L-lactide/glycolide copolymer material is recovered to room temperature, and opening the package;

and (3) drying: drying the raw materials before melting;

and (3) melting and injection molding: adding the dried raw materials into a single-screw extruder for melt injection molding;

and (3) post-treatment: and carrying out injection molding post-treatment by means of oriented stretching and heat treatment.

Preferably, the drying method comprises vacuum drying at 40-80 ℃ for 4-6 hours under low vacuum or drying by adopting a drying agent with a dew point of-40 ℃ to-50 ℃.

Preferably, the melt injection molding conditions are: the temperature of a machine barrel is 180-215 ℃, the temperature of a die is 65-80 ℃, the injection pressure is 90-100 MPa, and the injection speed is 55-70 cm³And/s, the retention time of the melt is 10-20 min.

Preferably, the stretching temperature is 75-95 ℃, and the heat treatment temperature is 95-105 ℃.

In conclusion, the beneficial technical effects of the invention are as follows: the absorbable skull lock is made of absorbable materials (lactide/glycolide copolymers), is suitable for both adult and child patients, can reduce the possibility of bone growth inhibition, implant displacement, implant touch, temperature-sensitive reaction and the like caused by the skull lock after operation, does not influence the effect of postoperative imaging (CT, MRI and X-ray), is favorable for rechecking postoperative focus positions, and is particularly favorable for patients needing to continue to receive radiotherapy after the operation.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to be implemented in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

The invention is further described below with reference to the accompanying drawings, in which:

fig. 1 is a schematic structural diagram of an absorbable skull lock for fixing bone flap obtained by the manufacturing method of embodiment 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It is to be noted that the drawings are merely illustrative and not to be drawn to strict scale, and that some portions may be enlarged or reduced for convenience of description, and some default may be made for a known portion.

EXAMPLE 1 manufacture of an absorbable skull Lock

Material pretreatment: the absorbable L-lactide/glycolide copolymer material is taken out from the low-temperature environment (-15 ℃), placed to be recovered to room temperature and then is unpacked.

And (3) drying: the raw materials are dried before melting, and the drying can be carried out by a dehumidifying drier or a vacuum drier. Vacuum drying is carried out at 60 ℃ under low vacuum for 5 hours.

And (3) melting and injection molding: the dried raw materials are added into a single screw extruder, the temperature of a machine barrel is 195 ℃, the temperature of a die is 70 ℃, the injection pressure is 95MPa, and the injection speed is 60cm³Melt residence time 15 min.

And (3) post-treatment: and carrying out injection molding post-treatment by means of directional stretching and heat treatment to obtain the absorbable skull lock. The stretching temperature was 85 ℃ and the heat treatment temperature was 100 ℃.

Fig. 1 is a schematic structural diagram of an absorbable skull lock for fixing bone flap obtained by the manufacturing method of embodiment 1. As shown in figure 1, an absorbable skull lock for fixing bone flaps is shown, and comprises a lower pressing plate 1, wherein a screw rod 2 is integrally formed in the middle of one end face of the lower pressing plate 1, and a handle 3 is fixed at one end of the screw rod 2, which is far away from the lower pressing plate 1. An upper pressing sheet 4 is sleeved on the outer edge of the screw rod 2, and a fixed tooth is arranged on one end face of the upper pressing sheet 4 relative to the lower pressing sheet 1. The upper pressing plate 4 has an internal thread, the screw 2 has an external thread, and the internal diameter of the internal thread matches the external diameter of the screw 2, so that the upper pressing plate 4 can be fitted on the screw 2 and move relative to the screw 2 by the thread. Preferably, the lower pressing plate 1, the screw 2 and the upper pressing plate 4 are all made of absorbable L-lactide/glycolide copolymer (PLGA) material. The handle 3 is made of Polycarbonate (PC). The lower pressing sheet 1 and the upper pressing sheet 4 are both circular. The diameter D of the lower and upper press plates 1 and 4 is 14 mm. The total length L of the resulting skull lock is 56 mm.

The working process of the skull lock is as follows: (1) placing a skull lock: after the skull flap is removed, at least 3 skull lock products are placed along the bone window line, and the lower compression plate is positioned between the dura mater and the skull. (Note: skull lock product should be placed evenly around the bone flap, so if 3 skull lock products are used, it should be placed at 120 ° angle; if 4 skull lock products are used, it should be placed at 90 °) (2) the bone flap is repositioned. (3) Rotation and fixation: and synchronously finishing the rotation fixation of all the skull locks. The screw shaft is ensured to be vertical to the incision, the handle is lightly held to enable the lower pressing sheet to be tightly attached to the inner surface of the skull, meanwhile, the upper pressing sheet is rotated anticlockwise until the upper pressing sheet is tightly attached to the upper surface of the skull, the upper pressing sheet is lightly pressed, and the handle is clockwise screwed to fix the skull lock firmly. (4) Cutting off the screw: the screw was cut off with an electric heating pen, leaving a 2 mm stub. (5) Ironing the stub: and ironing the residual stub by using an electric heating pen ironing head.

The above-mentioned embodiments, which further illustrate the objects, technical solutions and advantages of the present invention, should be understood that the above-mentioned embodiments are only exemplary of the present invention, and not restrictive, and any simple modifications, equivalent changes and modifications made to the above-mentioned embodiments according to the technical spirit of the present invention are within the scope of the technical solutions of the present invention.