CN215458999U - Assembly type distal femur tumor type bionic prosthesis containing universal assembly - Google Patents

Abstract

The utility model relates to a combined type distal femur tumor type bionic prosthesis containing a universal component, which comprises the following components: the femur component comprises a femur far end, and the lower end of the femur far end is provided with a first groove and two through holes positioned at two ends of the first groove; the tibia assembly comprises a tibia platform, and a second groove is formed in the tibia platform; a cushioning assembly including a pad disposed at an upper end of the tibial plateau; the universal assembly comprises a universal shaft and a pin shaft, the upper end of the universal shaft is installed in the first groove, the lower end of the universal shaft is installed in the second groove, and the pin shaft penetrates through the through holes and is used for connecting the distal end of the femur with the tibial plateau. The utility model adds the integrated universal component in the distal femur tumor type prosthesis, effectively disperses the stress borne by the prosthesis and prolongs the service life of the prosthesis.

Description

Assembly type distal femur tumor type bionic prosthesis containing universal assembly

Technical Field

The utility model relates to a combined type distal femur tumor type bionic prosthesis containing a universal component, and belongs to the technical field of medical equipment.

Background

The distal femur is the site of a malignant bone tumor. At present, the method for treating the malignant bone tumor at the part mainly comprises the steps of cutting off tumor sections, completely taking down the tumor, and then reconstructing defective bone by using an artificial hinge knee joint prosthesis.

The prior distal femur tumor type hinge knee joint on the market has the following two defects:

1. from a design perspective: the tumor type distal femoral prosthesis sold in the market at present only has a pure hinge and a rotary hinge. The two simple structural designs greatly limit the movement of the knee joint prosthesis in all directions, and the movement is greatly different from the movement (flexion, extension, rotation and the like) of a normal knee joint, so that the bionic degree cannot be completely reached. Therefore, the prosthesis has the hidden troubles of fracture, fatigue failure, serious abrasion, fracture around the prosthesis and the like. Especially in juvenile cases. The knee joint activity of children and teenagers is larger than that of adults, and in addition, the skeleton gradually grows to be mature, and the common hinge knee joint bears the influence of stress of the skeleton in all directions in the process of knee joint movement for hundreds of thousands of times. Conventional hinged knee joints prevent dislocation of the knee joint by limiting movement of the knee joint in all directions through the hinge, but this stabilization comes at the expense of movement. Although the metal hinge can mechanically prevent the knee joint from moving, forces in all directions still exist in the movement process of a person, so that the prosthesis which does not conform to the kinematics of the human body can have metal fatigue fracture, abrasion and even fracture around the prosthesis in the long-term and long-term accumulated movement process. The rotary hinge knee joint is also based on the same principle, has more rotary functions than the common hinge knee joint, and can not truly achieve the bionic purpose because the rotation is mainly platform rotation. Eventually, the stresses in different directions will cause fatigue fracture at the interface of the platform and the pad.

2. From a material perspective: the commercial tumor type distal femoral prosthesis mainly comprises cobalt, chromium and molybdenum (CoCrMo)The distal femur of the alloy, the tibial plateau and medullary canal rod of medical titanium alloy (Ti6Al4V), and a liner of Polyethylene (PE). The two materials have excellent wear resistance and mechanical strength, and can ensure that a patient can obtain immediate joint stabilization after being implanted. However, as an endoprosthesis for use in the bone oncology department, it has some disadvantages. First, a CoCrMo alloy (density: 8.9 g/cm)³) The prepared prosthesis has overlarge weight, can accelerate the load of peripheral bone, and can possibly cause fracture and abrasion; secondly, metal particles generated by the CoCrMo alloy in the abrasion process can cause inflammatory reaction and osteolysis of surrounding tissues; thirdly, the elastic modulus (220GPa) of the CoCrMo alloy is far greater than that of human skeleton (3-20GPa), and the CoCrMo alloy can cause stress shielding effect after being implanted, thereby causing fatigue fracture of prosthesis and fracture around the prosthesis; finally, CoCrMo alloy can scatter after radiation irradiates on the surface of the CoCrMo alloy, so that metal artifacts are generated, the artifacts influence doctors to observe tiny recurrent lesions to cause irrecoverable consequences when CT or X-ray examination is carried out on one hand, and influence radiation dose estimation when tumor radiotherapy is carried out on the other hand, and scattered radiation can damage surrounding normal tissues. Therefore, a distal femur tumor type prosthesis with adaptive mechanical properties, light weight and good light transmittance is urgently needed.

In summary, the existing distal femur tumor type hinge knee joint still has the following problems:

1) the motion behaviors of the conventional hinge knee joint and the normal knee joint of a human body are not matched, and the service life of a prosthesis part is shortened due to multidirectional stress; 2) the modulus of elasticity of the CoCrMo alloy is not matched with that of the skeleton, so that the stress shielding phenomenon is easily generated after the CoCrMo alloy is implanted, the loss of the bone mass is accelerated, and the risk of secondary fracture is increased; 3) the CoCrMo alloy has overlarge density, and can increase the burden of host bones after being implanted to cause fracture or abrasion, so that the prosthesis fails; 4) the CoCrMo alloy can generate toxic metal abrasion particles in the using process to cause inflammatory reaction of surrounding tissues; 5) the CoCrMo alloy material can generate serious scattering and metal artifacts when irradiated by radiation.

Disclosure of Invention

Aiming at the outstanding problems, the utility model provides the assembled distal femur tumor type bionic prosthesis containing the universal component, and the stress borne by the prosthesis is effectively dispersed and the service life of the prosthesis is prolonged by adding the integrated universal component.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a combined type distal femur tumor type bionic prosthesis comprising a universal component comprises the following components:

the femur component comprises a femur far end, and the lower end of the femur far end is provided with a first groove and two through holes positioned at two ends of the first groove;

the tibia assembly comprises a tibia platform, and a second groove is formed in the tibia platform;

a cushioning assembly including a pad disposed at an upper end of the tibial plateau;

the universal assembly comprises a universal shaft and a pin shaft, the upper end of the universal shaft is installed in the first groove, the lower end of the universal shaft is installed in the second groove, and the pin shaft penetrates through the through holes and is used for connecting the distal end of the femur with the tibial plateau.

The assembled distal femur tumor type bionic prosthesis preferably comprises an upper end part, a middle transition part and a lower end part, wherein the upper end part is of a cylindrical tubular structure, the middle transition part is an arc-shaped curved surface, the lower end part is a ball head, and the second groove is an arc-shaped groove matched with the ball head.

The assembled distal femur tumor type biomimetic prosthesis preferably further comprises a universal shaft sleeve, wherein the universal shaft sleeve is assembled between the ball head and the second groove and used for reducing the friction force between the ball head and the second groove.

The assembled distal femur tumor type bionic prosthesis preferably further comprises a first shaft sleeve and a second shaft sleeve, wherein the first shaft sleeve and the second shaft sleeve are respectively sleeved at two ends of the pin shaft and used for reducing friction force between the pin shaft and the through hole.

The two shaft sleeves are made of metal and CFR-PEEK materials, and are designed for reducing friction between the CFR-PEEK and the metal materials.

The assembled distal femur tumor-type biomimetic prosthesis preferably further comprises a femoral bone marrow cavity rod and an extension rod, wherein the lower end of the extension rod is connected with the upper end of the distal femur end, and the upper end of the extension rod is connected with the lower end of the femoral bone marrow cavity rod.

Preferably, the assembled distal femur tumor-type biomimetic prosthesis further comprises a tibial bone marrow cavity rod connected with the lower end of the tibial platform.

Preferably, the universal shaft and the pin shaft are fixedly connected through a fastener.

The assembled distal femur tumor type bionic prosthesis is characterized in that the distal femur is preferably a distal femur prosthesis made of CFR-PEEK material, and the buffer component and the universal shaft sleeve are made of PE material or CFR-PEEK material.

Preferably, the content of the carbon fiber in the CFR-PEEK is 20-40 wt%.

The assembled distal femur tumor type bionic prosthesis is preferably characterized in that the weight average molecular weight of the CFR-PEEK is 8-12 ten thousand, the number average molecular weight is 2-4 ten thousand, the molecular weight distribution is 3.2-3.8, and the polymerization degree is 100-110.

Due to the adoption of the technical scheme, the utility model has the following advantages:

1. the Carbon Fiber modified Polyether Ether Ketone (CFR-PEEK) material adopted by the utility model has good mechanical strength (compressive strength, bending strength, yield stress and impact strength) and biological safety. In one aspect, CFR-PEEK has a lower density than metal, and a density of only 1.38g/cm³On the other hand, the weight of the prosthesis can be effectively reduced by using the material as the prosthesis materialThe weight of the internal plants is reduced, the burden of host bones is lightened, and the early immediate stability of the prosthesis is facilitated; on the other hand, the elastic modulus of CFR-PEEK (about 18 GPa) is similar to that of human bones (3-20GPa), and is lower than that of medical titanium alloy (110 GPa). Therefore, after the bone fracture implant is implanted into a human body, the stress shielding effect can be effectively avoided, and the risk of secondary fracture and bone loss is reduced. In a third aspect, the wear particles of CFR-PEEK material are less tissue toxic than the CoCrMo alloy wear particles.

2. The CFR-PEEK disclosed by the utility model has excellent light transmittance, so that the CFR-PEEK has very important application value in the field of orthopedics, particularly bone oncology. CFR-PEEK material eliminates the interference of metal artifacts, and can help doctors to find early tumor recurrence; in addition, the CFR-PEEK material can also solve the problem of ray refraction, and after the problem of ray refraction is solved, on one hand, an orthopedic doctor can judge the radiotherapy dosage more accurately, and on the other hand, surrounding tissues are protected better. The appearance of CFR-PEEK material also provides a very good alternative solution to the problem that the release of metal ions during the abrasion of CoCrMo prosthesis causes tissue inflammation.

3. The universal module completely subverts the design of the prosthesis in the prior art, the ball head extending from the cylindrical sleeve to the lower part is generally called as a universal shaft, and the integrated streamline design is adopted, so that the condition that the cylindrical sleeve and the lower connecting point are easy to fatigue fracture in the prior art is improved, and the mechanical design is more reasonable. The screw fixation is added at the connection position of the universal shaft and the pin shaft, so that the stability of the prosthesis in bending and stretching motion is improved.

4. The utility model uses CFR-PEEK material to replace all the distal femur part of the tumor prosthesis for the first time, and adds the integrated universal component in the distal femur tumor prosthesis for the first time, thereby effectively dispersing the stress on the prosthesis and prolonging the service life of the prosthesis.

Drawings

FIG. 1 is a schematic perspective view of a distal femur of a modular biomimetic prosthesis of distal femur tumor type with gimbaled components according to an embodiment of the present invention;

FIG. 2 is a side view of the distal end of a femur of the assembled biomimetic prosthesis of distal tumor type of femur with gimbaled components according to the embodiment of the present invention;

FIG. 3 is an exploded view of a modular distal femoral tumor-type biomimetic prosthesis with gimbaled components according to this embodiment of the present invention;

FIG. 4 is a combination view of a modular distal femoral tumor-type biomimetic prosthesis with gimbaled components according to this embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a tumor-type knee prosthesis provided in the prior art;

1-femoral medullary canal rod; 2-an extension rod; 3-distal femur, 301-first through hole, 302-second through hole, 303-first groove; 4-cardan shaft, 401-lower end, 402-middle transition, 403-upper end; 5-a pin shaft; 6-a first shaft sleeve; 7-a second shaft sleeve; 8-universal shaft sleeve; 9-a liner; 10-tibial plateau; 11-tibial medullary cavity rod; 12-screws.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are described clearly and completely below, and it is obvious that the described embodiments are some, not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. As used herein, the terms "first," "second," "third," "fourth," and the like do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

As shown in fig. 1 and 2, the utility model provides a combined type distal femur tumor type biomimetic prosthesis comprising a universal component, which comprises the following components: the femur component comprises a femur far end 3, and the lower end of the femur far end 3 is provided with a first groove 303 and two through holes positioned at two ends of the first groove 303; the tibia assembly comprises a tibia platform 10, and a second groove is formed in the tibia platform 10; the cushioning component comprises a gasket 9, and the gasket 9 is arranged at the upper end of the tibial platform 10; universal assembly, universal assembly include cardan shaft 4 and round pin axle 5, and install in first recess 303 the upper end of cardan shaft 4, and the lower extreme is installed in the second recess, and round pin axle 5 wears to establish between two through-holes for link together thighbone distal end 3 and tibial plateau 10.

In a preferred embodiment of the present invention, the cardan shaft 4 comprises an upper end 403, an intermediate transition 402 and a lower end 401, the upper end 403 is a cylindrical tubular structure, the intermediate transition 402 is an arc-shaped curved surface, the lower end 401 is a ball head, and the second groove is an arc-shaped groove adapted to the ball head. Because the lower end of the universal shaft 4 is connected with the second groove through the ball head, the universal shaft allows the prosthesis to have micro-motion in all directions in the moving process, and compared with the traditional hinge knee joint prosthesis, the hinge knee joint prosthesis can better decompose the stress born in all directions, and the service life of the prosthesis is prolonged.

In a preferred embodiment of the utility model, the gimbal assembly further comprises a gimbal sleeve 8, the gimbal sleeve 8 being fitted between the ball head and the second recess for reducing friction between the ball head and the second recess.

In a preferred embodiment of the present invention, the buffering assembly further includes a first bushing 6 and a second bushing 7, and the first bushing 6 and the second bushing 7 are respectively sleeved on two ends of the pin 5.

In a preferred embodiment of the present invention, the femoral component further comprises a femoral medullary canal rod 1 and an extension rod 2, a lower end of the extension rod 2 is connected with an upper end of the distal femur end 3, and an upper end of the extension rod 2 is connected with a lower end of the femoral medullary canal rod 1. The femur intramedullary rod 1, the extension rod 2 and the tibia platform 10 are made of conventional Ti6Al4V materials, because the femur intramedullary rod 1 is a stable device immediately after the implantation of the tumor-type knee joint prosthesis, and the shearing force to be borne by the junction between the prosthesis and the medullary cavity is large, so that metal materials are still used here. In addition, the femoral medullary cavity rod 1 can be designed into different models according to the length and the width of the medullary cavity of a patient.

In a preferred embodiment of the utility model, the tibial component further comprises a tibial medullary canal rod 11, the tibial medullary canal rod 11 being connected to the lower end of the tibial plateau 10. Tibial medullary canal rod 11 is also made of conventional Ti6Al4V material for added stability of fixation.

In a preferred embodiment of the utility model, the cardan shaft 4 and the pin 5 are fastened together by means of fasteners. Specifically, the cardan shaft 4 and the pin 5 are fastened with screws 12 to enhance stability therebetween.

In a preferred embodiment of the present invention, the distal femur 3 is a distal femoral prosthesis made of CFR-PEEK material, and the bumper assembly and the gimbal 8 are made of PE material or CFR-PEEK material.

In a preferred embodiment of the present invention, the carbon fiber content in CFR-PEEK is 20 to 40 wt%.

In a preferred embodiment of the utility model, the CFR-PEEK has a weight average molecular weight of 8-12 ten thousand, a number average molecular weight of 2-4 ten thousand, a molecular weight distribution of 3.2-3.8, and a degree of polymerization of 100-110.

To further illustrate the role of carbon fibers in modified polyetheretherketone, the utility model performs the following experiments:

example 1

In the CFR-PEEK adopted in the embodiment, the polymerization degree of the PEEK is 105, the number average molecular weight is 3.4 ten thousand, the weight average molecular weight is 10 ten thousand, the molecular weight distribution is 3.2-3.8, the content of carbon fibers is 30 wt%, and the mechanical properties and the density of the CFR-PEEK are shown in Table 1.

Examples 2 to 6

Examples 2 to 6 differ from example 1 in that: the content of the carbon fiber is different, and the specific test result is detailed in table 1.

Table 1 shows the effect of different carbon fiber contents on the mechanical properties and density of PEEK

As can be seen from table 1, with increasing proportions of carbon fibres, the modulus of elasticity and tensile strength of the prosthesis are also increased, the stiffness is increased, but the toughness is decreased. When the carbon fiber content reaches 60%, the material has no modeling function and is very hard, and the material is not suitable for preparing joint prosthesis. Therefore, through continuous attempts, the mechanical property of the CFR-PEEK material with the weight percentage of 30 wt% is finally determined to be the most suitable for being used as a knee joint prosthesis, and the rigidity and the toughness are both considered. In the present invention, the carbon fibers are short fibers, and the fiber distribution direction is randomly distributed.

Example 7

This example is the same as example 3, wherein the content of carbon fibers is 30 wt%, the degree of polymerization of PEEK is 105, the number average molecular weight is 3.4 ten thousand, the weight average molecular weight is 10 ten thousand, and the molecular weight distribution is 3.2 to 3.8.

Examples 8 to 12

Examples 8-12 differ from example 7 in that: the degree of polymerization and molecular weight distribution of PEEK were different, and are specifically shown in table 2.

Table 2 shows the mechanical properties and densities of PEEK of different degrees of polymerization

It can be seen from table 2 that the elastic modulus and tensile strength of the prosthesis are gradually increased and the stiffness is gradually increased with the gradually increasing degree of polymerization and molecular weight distribution. When the polymerization degree is 150, the elastic modulus of the CFR-PEEK material exceeds the elastic modulus bearing range of human femurs, so that the mechanical properties of the CFR-PEEK material with the polymerization degree of 105 and the molecular weight distribution of 3.2-3.8 are determined to be most suitable for being used as knee joint prostheses.

As shown in fig. 5, which is a tumor-type knee joint prosthesis provided in the prior art, the distal femoral prosthesis 11 includes a prosthesis main body 111 and two protective shells 112 made of two pieces of PE material and covering both sides of the prosthesis main body 111. The two side shields 112 are fixed to the distal femoral prosthesis 11 by titanium alloy screws. In the using process, the titanium alloy screw can cut the protective shell 112 and the distal femoral prosthesis 11, so that the protective shell 112 is broken, the distal femoral prosthesis 11 is abraded and the like, and meanwhile, the screw is in fatigue fracture due to the stress shielding effect generated by the contact of two materials with excessively different elastic moduli.

On the other hand, the prior art tibial plateau prosthesis 21 does not have a universal joint assembly, and the tibial component 2 and the distal end of the femur are connected by a highly restrictive hinge arrangement. This hinge assembly is integral with tibial plateau prosthesis 21, cannot be disassembled, and can only be jogged according to the preset angle (preset angle is 3 °) and direction, with very high restriction. Therefore, the human body still cannot meet the requirement of stress dispersion in the process of sudden starting running, transverse movement and rotation. The utility model is provided with the independently assembled universal assembly which can generate a micromotion of 360 degrees, perfectly deals with the stress generated in the motion process and greatly prolongs the service life of the prosthesis. And the knee joint motion law of the normal human body is better met, and the effect of complete bionics is achieved.

The elastic modulus of the CFR-PEEK provided by the utility model is about 18GPa, is similar to the elastic modulus of human thighbone 3-20GPa, and is lower than that of medical titanium alloy (110 GPa). Therefore, after the bone fracture implant is implanted into a human body, the stress shielding effect can be effectively avoided, and the risk of secondary fracture is reduced. In addition, the density of CFR-PEEK is only 1.38g/cm³The weight of the prosthesis can be effectively reduced when the prosthesis is used as a prosthesis material; the wear particles of CFR-PEEK material are not as tissue toxic as CoCrMo wear particles; and the excellent light transmission performance of the CFR-PEEK effectively reduces the scattering of radioactive rays, thereby solving the problem of metal artifacts.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (7)

1. A matched stack formula thighbone distal tumor type bionic prosthesis that contains universal subassembly which characterized in that includes following part:

the femur component comprises a femur far end (3), and the lower end of the femur far end (3) is provided with a first groove (303) and two through holes positioned at two ends of the first groove (303);

the tibia assembly comprises a tibia platform (10), and a second groove is formed in the tibia platform (10);

a cushioning assembly comprising a pad (9), the pad (9) being disposed at an upper end of the tibial plateau (10);

universal assembly, universal assembly includes cardan shaft (4) and round pin axle (5), install the upper end of cardan shaft (4) in first recess (303), the lower extreme is installed in the second recess, round pin axle (5) wear to establish two between the through-hole, be used for with thighbone distal end (3) with tibial plateau (10) link together.

2. The assembled distal femoral tumor-type biomimetic prosthesis according to claim 1, wherein the universal shaft (4) comprises an upper end portion (403), a middle transition portion (402), and a lower end portion (401), the upper end portion (403) is a cylindrical barrel-shaped structure, the middle transition portion (402) is an arc-shaped curved surface, the lower end portion (401) is a ball head, and the second groove is an arc-shaped groove adapted to the ball head.

3. The modular distal femoral tumor-type biomimetic prosthesis according to claim 2, characterized in that the gimbal assembly further comprises a gimbal sleeve (8), the gimbal sleeve (8) being fitted between the ball head and the second groove for reducing friction between the ball head and the second groove.

4. The assembled distal femoral tumor-type biomimetic prosthesis according to claim 1, wherein the buffer assembly further comprises a first shaft sleeve (6) and a second shaft sleeve (7), the first shaft sleeve (6) and the second shaft sleeve (7) are respectively sleeved on two ends of the pin shaft (5).

5. The modular distal femoral tumor-type biomimetic prosthesis according to claim 1, characterized in that the femoral component further comprises a femoral medullary canal rod (1) and an extension rod (2), wherein the lower end of the extension rod (2) is connected with the upper end of the distal femur (3), and the upper end of the extension rod (2) is connected with the lower end of the femoral medullary canal rod (1).

6. The modular distal femoral tumor-type biomimetic prosthesis according to claim 1, characterized in that the tibial component further comprises a tibial medullary rod (11), the tibial medullary rod (11) being connected with a lower end of the tibial plateau (10).

7. The assembled distal femoral tumor-type biomimetic prosthesis according to claim 1, characterized in that the cardan shaft (4) and the pin shaft (5) are fastened together by a fastener.

Images