WO2014201763A1 - Composite implant for fixing human skeleton - Google Patents

Abstract

Disclosed is a composite implant for fixing a human skeleton and which is prepared from multiple raw materials via hot pressing. The mass percentage of each component in the multiple raw materials is as follows: polyamide 6 fibre, 23%-24%; the copolymer of methyl methacrylate and N-vinylpyrrolidone, 45%-65%; and hydroxyapatite micropowder, 2%-15%. The composite implant has stable chemical properties, a good biocompatibility, will not degrade in the body, and has comparatively good properties of bending, compressive strength, impact strength, fracture and fatigue strength and the like.

Description

Technical field

 The present invention relates to the field of bone trauma and orthopedic medicine, and in particular to a composite implant for bone fixation in humans.

Background technique

 In modern bone trauma applications, fracture, maxillofacial and cranial repair surgery is one of the important orthopedic surgery. Conventional orthopedic surgery usually uses metal materials (titanium alloy, stainless steel, etc.) for fixation, fixation, repair, and the like. The metal internal fixation remains in the patient after the wound is healed, and the strength does not change. Thus, the hard metal internal fixation is easy to cause stress shielding during the bone healing process, which is not conducive to the growth of the new bone, and may cause the fracture to occur again after healing. The risk of fracture. Therefore, most of these metal internal fixations require a second surgery to remove after the wound is cured, which not only increases the patient's pain, but also increases the patient's treatment cost. In addition, after the metal internal fixation is implanted into the human body, the patient should not be subjected to radioactivity and magnetic resonance imaging, thereby affecting the in-depth observation and treatment of the patient's condition.

 At present, there is a device for manufacturing an intraosseous fixture using an absorbable polylactic acid polymer material, which has physical properties such as better bending strength and can be absorbed in the human body after wound healing, thereby avoiding The removal of the bone internal fixation. However, the intraosseous fixative of this type of polylactic acid polymer material also has the following drawbacks:

 1. Its degradation rate is faster than bone healing time, and it is easy to produce sinus and body fluid;

 2. The degradation products are acidic, resulting in sterile inflammation in the implanted environment;

 3. The elastic modulus, bending strength and shear strength are relatively low, which is prone to fracture failure.

Summary of the invention

 SUMMARY OF THE INVENTION The object of the present invention is to provide a composite implant for human bone fixation, which not only ensures complete and effective healing of the fracture, but also avoids problems caused by degradation of the polylactic acid material.

In order to achieve the above object, the present invention provides a composite implant for human bone fixation, It is prepared by hot pressing from various raw materials, and the mass percentage of each component in the various raw materials is: polyamide 6 fiber 23%~40%, methyl methacrylate and N-vinylpyrrolidone The copolymer is 45%~65% and the hydroxyapatite powder is 2%~15%.

 Further, in the above composite implant for human bone fixation, the mass percentage of each of the plurality of raw materials is:

 Polyamide 6 fiber 23%, methyl methacrylate and N-vinylpyrrolidone copolymer 65% and hydroxyapatite fine powder 12%.

 Further, in the above composite implant for human bone fixation, the mass percentage of each of the plurality of raw materials is:

 Polyamide 6 fiber 35%, methyl methacrylate and N-vinylpyrrolidone copolymer 50% and hydroxyapatite fine powder 15%.

 Further, in the above composite implant for human bone fixation, the mass percentage of each of the plurality of raw materials is:

 Polyamide 6 fiber 35%, methyl methacrylate and N-vinylpyrrolidone copolymer 45% and hydroxyapatite fine powder 10%.

 Further, in the above composite implant for human bone fixation, the composite implant is a bone screw or a fixation rod used for attachment and fixation of cancellous bone fracture.

 Further, in the above composite implant for human bone fixation, the composite implant is a micro-plate and a micro-screw for craniofacial repair.

 Further, in the above composite implant for human bone fixation, the composite implant is a rib fixation nail and a sternal fixation nail for a fixed connection of a rib sternal fracture.

 Further, in the above composite implant for human bone fixation, the composite implant is a tying line for bone internal fixation bundling.

 Further, in the above composite implant for human bone fixation, the composite implant has a flexural strength of 140 MPa and a flexural modulus of 3 GPa.

 Further, in the above composite implant for human bone fixation, the composite implant has a shear strength of 100 MPa.

The composite implant for human bone fixation has stable chemical property and good biocompatibility, and does not degrade in the human body, ensuring complete and effective healing of the fracture, and avoiding degradation of the polylactic acid material. The resulting composite implant has better bending, compression, impact and fracture fatigue strength properties, and can be implanted into the human body for a long time without secondary removal, saving a lot of medical resources and reducing The pain and financial burden of the patient.

detailed description

 The invention relates to a composite implant for human bone fixation, which is prepared by hot pressing from a plurality of raw materials, and the mass percentage of each component in the plurality of raw materials is:

 Polyamide 6 fiber 23%~40%, methyl methacrylate and N-vinylpyrrolidone copolymer 45%~65% and hydroxyapatite powder 2%~15%.

 The sum of the mass percentages of the components in the plurality of raw materials is 100%.

 The composite implant of the present invention is a long fiber reinforced thermoplastic resin composite, wherein the polyamide 6 fiber (nylon 6) has good elasticity and better impact strength, which improves the composite implant Resistance to bending, compression and impact strength.

 The methyl methacrylate and the N-vinylpyrrolidone copolymer have good complexability, and the polyamide 6 fiber is bonded and stabilized; the polymer has a sustained release function, and after being implanted in the body, by absorbing the tissue fluid A certain degree of swelling occurs, the stiffness gradually decreases and the toughness gradually increases, and as the volume increases, the hydroxyapatite can better contact the bone tissue.

 The hydroxyapatite micropowder has good osteoconductivity, and preferably promotes epithelial growth of bone cells and deposition and solidification.

 The composite implant of the invention forms a fiber reinforced product by using the raw materials of the above components, which has better properties such as vibration damping, impact resistance and fracture fatigue strength, and has stable chemical properties and good biocompatibility. The implant site can produce good bone bonding and has passed the biosafety test of the Sichuan Medical Device Biomaterials and Products Testing Center.

 The physical properties of the composite implant are as follows:

 Bending strength 140MPa;

 Compressive strength ^ lOOMPa;

 Shear strength ^lOOMPa;

Impact strength 200KJ/m2 _;

The flexural modulus is 3Gpa. After the composite implant of the invention is implanted into a patient, it is deposited and deposited by hydroxyapatite to promote epithelial growth and deposition of bone cells, and finally achieve the purpose of bone healing.

 In addition, the polyamide 6 fiber of the composite implant of the present invention is chemically stable, and its amide group is almost the same as the amide group in the protein, and it hardly degrades for a long time, methyl methacrylate and N-ethylene. The pyrrolidone copolymer is chemically stable and does not degrade into small molecules. Hydroxyapatite is the same as the inorganic component in human bone, and it promotes osteoblast deposition without degradation. The composite implant of the invention does not undergo degradation, but is permanently stored in the body as a bone substitute.

 The composite implant of the invention can accelerate the early healing of the fracture, has sufficient biomechanical strength and maintenance time, ensures the complete healing of the fracture, and avoids the degradation rate of the existing polylactic acid polymer material faster than the bone healing time. It is prone to problems of sinus and body fluid accumulation and the problem of aseptic inflammation in the implanted environment due to the acidic nature of the degradation products.

 The composite implant of the present invention does not cause liquid accumulation in medical applications, does not cause sinus, acid-free and metal ion environment, and chemical stability does not cause acute or chronic toxic side effects to the human body. Moreover, the composite implant has better properties such as bending, compression resistance, impact resistance and fracture fatigue strength, and can be implanted into the human body for a long time without secondary removal, thereby saving a large amount of medical resources and reducing the patient. The pain and financial burden.

 The composite implant for human bone fixation of the invention expands the application range of the human implant, and can be made into an intraosseous fixation device for various types of applications. Moreover, the composite implant of the present invention is non-electromagnetic and does not interfere with radiographic imaging and radiotherapy.

 The composite implant of the present invention differs slightly in the proportion of its components depending on the site of use of the human body. Since the material of the composite implant has good designability and plastic freedom, a variety of implantable devices for human bone fixation can be prepared, including but not limited to the following: for cancellous Bone screws or fixation rods for bone fracture fixation, micro-plates and micro-screws for craniofacial repair, rib fixation nails for rib sternal fracture fracture fixation, sternal fixation nails and for internal fixation Bundled bundles. Each of the above products has different biomechanical properties due to different parts of the human body, and therefore, the respective ratios are slightly different within the ratio range given by the present invention.

In summary, the composite implant for human bone fixation of the present invention is designed based on a bionic principle by adopting a new polymer material and a new molding concept, and has a free and sufficient mechanical property design property. According to different parts implanted in the human body, the material is guaranteed to have sufficient compressive, shear, bending, impact and fatigue strength. Moreover, it has stable chemical properties and good biocompatibility. It can be removed after being implanted into the human body without the need for secondary surgery, which avoids the disadvantages of metal materials and polylactic acid materials, and reduces the suffering and economic burden of patients. Preferred embodiments of the present invention are described in detail below. Embodiment 1

 A composite implant for human bone fixation, which is prepared by hot pressing of a plurality of raw materials by a resin, and the mass percentage of each component in the plurality of raw materials is:

 Polyamide 6 fiber 23%, methyl methacrylate and N-vinylpyrrolidone copolymer 65% and hydroxyapatite fine powder 12%. Embodiment 2

 A composite implant for human bone fixation, which is prepared by hot pressing of a plurality of raw materials by a resin, and the mass percentage of each component in the plurality of raw materials is:

 Polyamide 6 fiber 40%, methyl methacrylate and N-vinylpyrrolidone copolymer 50% and hydroxyapatite fine powder 10%. Embodiment 3

 A composite implant for human bone fixation, which is prepared by hot pressing of a plurality of raw materials by a resin, and the mass percentage of each component in the plurality of raw materials is:

 Polyamide 6 fiber 35%, methyl methacrylate and N-vinylpyrrolidone copolymer 50% and hydroxyapatite fine powder 15%. Embodiment 4

 A composite implant for human bone fixation, which is prepared by hot pressing of a plurality of raw materials by a resin, and the mass percentage of each component in the plurality of raw materials is:

Polyamide 6 fiber 32%, methyl methacrylate and N-vinylpyrrolidone copolymer 65% and hydroxyapatite fine powder 2%. Embodiment 5

 A composite implant for human bone fixation, which is prepared by hot pressing of a plurality of raw materials by a resin, and the mass percentage of each component in the plurality of raw materials is:

 Polyamide 6 fiber 35%, methyl methacrylate and N-vinylpyrrolidone copolymer 45% and hydroxyapatite fine powder 10%. The description and application of the present invention are intended to be illustrative, and not intended to limit the scope of the invention. Variations and modifications of the embodiments disclosed herein are possible, and various alternative and equivalent components of the embodiments are well known to those of ordinary skill in the art. It will be apparent to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, ratios, and other components, materials and components without departing from the spirit or essential characteristics of the invention. Other variations and modifications of the embodiments disclosed herein may be made without departing from the scope and spirit of the invention.

Claims

claims 1. A composite implant for human bone fixation, characterized in that it is prepared from a variety of raw materials through hot pressing, and the mass percentage of each component in the multiple raw materials is: Polyamide 6 fiber 23%~40%, methyl methacrylate and N-vinylpyrrolidone copolymer 45%~65%, and hydroxyapatite micropowder 2%~15%. 2. The composite implant for human bone fixation according to claim 1, characterized in that the mass percentage of each component in the multiple raw materials is: Polyamide 6 fiber 23%, methyl methacrylate and N-vinylpyrrolidone copolymer 65% and hydroxyapatite micropowder 12%. 3. The composite implant for human bone fixation according to claim 1, characterized in that the mass percentage of each component in the multiple raw materials is: Polyamide 6 fiber 35%, methyl methacrylate and N-vinylpyrrolidone copolymer 50% and hydroxyapatite micropowder 15%. 4. The composite implant for human bone fixation according to claim 1, characterized in that the mass percentage of each component in the multiple raw materials is: Polyamide 6 fiber 35%, methyl methacrylate and N-vinylpyrrolidone copolymer 45% and hydroxyapatite micropowder 10%. 5. The composite implant for human bone fixation according to claim 1, characterized in that the composite implant is a bone screw or a fixation rod used for connection and fixation of cancellous bone fractures. 6. The composite implant for human bone fixation according to claim 1, characterized in that the composite implant is a micro bone plate and micro screw for craniofacial repair. 7. The composite implant for human bone fixation according to claim 1, characterized in that the composite implant is a rib fixation nail or a sternum fixation nail used for fixing and connecting ribs and sternum fractures. 8. The composite implant for human bone fixation according to claim 1, characterized in that the composite implant is a binding wire used for intraosseous fixation. 9. The composite implant for human bone fixation according to claim 1, characterized in that the composite implant has a flexural strength of 140MPa and a flexural modulus of 3Gpa. 10. The composite implant for human bone fixation according to claim 1, characterized in that,