CN109124747B - A Fracture External Fixation Bracket with Variable Rigidity - Google Patents

Abstract

The application discloses a fracture external fixation support with variable rigidity, which comprises a rigidity adjusting rod, a cross beam and a steel needle; the rigidity adjusting rod comprises a left supporting rod and a right supporting rod, a nut which can rotate along the right supporting rod is matched with the outer part of the right supporting rod, a flexible rod is connected between the left supporting rod and the right supporting rod, a spring is sleeved outside the flexible rod, one end of the spring is contacted with the right end of the left supporting rod, and the other end of the spring is contacted with the left end of the nut; the left support rod is fixedly connected with the left cross beam, the right support rod is fixedly connected with the right cross beam, and the left cross beam and the right cross beam are respectively connected with steel needles protruding out of the lower ends of the left cross beam and the right cross beam. The support can realize quantitative adjustment from low rigidity to high rigidity, and quantitative and directional adjustment during fracture II healing, so that the callus growth speed is higher and the fracture healing quality is higher.

Description

A Fracture External Fixation Bracket with Variable Rigidity

technical field

The invention relates to the field of medical instruments, in particular to a fracture external fixation bracket with variable stiffness.

Background technique

There are two types of fracture healing: Ⅰ healing and Ⅱ healing. Among them, phase II healing has a large number of calluses, which is an ideal form of fracture healing, and it is also a clinically desirable treatment result. For a long time, a large number of research results have proved that stress is one of the most important factors regulating fracture healing by intention. Because the existing research methods mostly choose a single stress form, which does not conform to the comprehensive stress of the fracture end of clinical patients, it is difficult to apply it to guide the treatment of fractures in clinical practice.

In the process of fracture healing, in fact, most fracture ends are subjected to multiple stresses such as lateral displacement, axial extrusion, bending, and rotation, and these stresses are in a dynamic process. After the fracture is reduced and fixed, the rehabilitation stress of the limb becomes the biggest variable factor affecting the stress of the fracture end. Rehabilitation stress has two important functions: one is to adjust the stress of fracture ends to affect fracture healing; the other is to restore joint and limb functions. These two functions directly determine the final effect of fracture treatment. Due to the arbitrary subjectivity of the rehabilitation process, the complexity of fracture fixation, and the uncertainty of fixation stability, fracture rehabilitation is still considered by the industry to be the most difficult treatment technique for fracture treatment.

In the prior art, in order to apply different stresses to the fracture ends at different stages of fracture healing, only multiple fixation brackets with different rigidities can be made. If different fixation brackets are selected for fixation at different periods, it is technically unavoidable to replace them. During the process, due to the short-term failure of the fixation, the fracture alignment and fracture healing will be adversely affected. How to use a set of device needles to adapt to the stress requirements of each period of fracture healing by changing the stiffness, or change the amount of rehabilitation to adjust the stress, so as to promote fracture healing and restore limb function, has always been a difficult problem to be solved in orthopedic clinics.

Contents of the invention

In order to solve the above problems, the present invention provides a fracture fixation bracket with variable stiffness, which can realize the quantitative adjustment from low stiffness to high stiffness, respectively, when the three changes of stem cell recruitment, differentiation, and osteogenesis in fracture II healing Timing, quantitative, and directional adjustments can be made to the points, so that the callus grows faster and the quality of fracture healing is higher.

In order to achieve the above object, the present invention takes the following technical solutions:

A fracture external fixation frame with variable rigidity, comprising a rigidity adjusting rod, a beam and a steel needle;

The stiffness adjusting rod includes a left pole and a right pole, the outside of the right pole is equipped with a nut that can rotate along the right pole, a flexible rod is connected between the left pole and the right pole, and the A spring is sheathed outside the flexible rod, one end of the spring is in contact with the right end of the left strut, and the other end of the spring is in contact with the left end of the nut;

The left pole is fixedly connected to the left crossbeam, the right pole is fixedly connected to the right crossbeam, the left crossbeam and the right crossbeam are respectively connected with steel needles, and the steel needles protrude from the lower ends of the left crossbeam and the right crossbeam.

Preferably, the right end of the left support rod is provided with a protrusion, and the right end surface of the protrusion is provided with a first groove for positioning the left end of the spring.

Preferably, the left end surface of the nut is provided with a second groove for positioning the right end of the spring.

Preferably, the spring is a cylindrical compression spring.

Preferably, the left beam or the right beam includes a first beam plate and a second beam plate that cooperate with each other, and a through hole is left in the middle of the first beam plate and the second beam plate after assembly, and the steel needle passes through the through hole , the first beam plate and the second beam plate are detachably connected by screws.

Beneficial effects of the present invention:

(1) In the present invention, by operating the nut to move along the right pole, the nut and the left pole can compress the spring to different degrees, so that the spring can produce different degrees of lateral stiffness, thereby changing the overall stiffness of the fixing bracket. After the fracture is reduced and fixed, by adjusting the stiffness of the fixation bracket, only one pair of fixation brackets can be used to realize the quantitative adjustment of the stress of the fracture end from low stiffness to high stiffness. By quantifying and changing the rehabilitation stress, controlling and adjusting the stress change of the fracture end can not only promote fracture healing, but also restore joint function. Multidirectional stress promotes periosteal intramembranous osteogenesis by recruiting more stem cells, regulating chondrocyte differentiation, and synergistically promoting cartilage and intramembranous osteogenesis, resulting in faster callus growth and higher fracture healing quality.

(2) The setting of the first groove and the second groove can accurately fix the spring, ensuring that the spring will not generate excess lateral force due to movement when it is compressed.

(3) The left beam or the right beam is assembled with the first beam plate and the second beam plate connected by screws, which is convenient for the replacement of steel needles and the disassembly and assembly of the whole device. The device has a high degree of modularization and good interchangeability.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a perspective view of the overall structure of the present invention;

Fig. 2 is a front view of the overall structure of the present invention;

Fig. 3 is a top view of the overall structure of the present invention;

Figure 4 is an enlarged view of A in Figure 3;

Figure 5 is an enlarged view of B in Figure 3;

In the figure: 1. left connecting block, 2. left strut, 3. spring, 4. right strut, 5. right connecting block, 6. connecting screw, 7. right beam, 8. steel needle, 9. bone tube , 10, screw, 11, protrusion, 12, first groove, 13, second groove, 14, nut, 15, left beam.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all of them. Based on the embodiments of this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

In describing the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", " The orientation or positional relationship indicated by "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, so as to Specific orientation configurations and operations, therefore, are not to be construed as limitations on the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features.

In the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

Aiming at the problems existing in the background technology, a three-phase cytological staging method for the fracture healing process was found in clinical and experimental studies, and it was clarified that there were obvious differences in the three phases of suitable stress, and thus a method of adjusting the stiffness of the fixator was proposed to establish It is suitable for the different stress environments of the three phases of fracture and promotes fracture healing. According to the previous research results, a kind of external fixator with variable stiffness and variable stiffness to promote fracture healing was designed and manufactured. Animal experiments have proved that the external fixator with variable stiffness to promote fracture healing can effectively promote the secondary healing of fractures in the treatment of fractures. Taking rat femur fracture as an example, the fixation bracket for promoting fracture healing will be further described below.

In the external fixation bracket shown in Figure 1-5, the two sides of the fracture end surface of the bone canal 9 are respectively fixed with steel pins 8, preferably with four steel pins, and the steel pins are selected from Italian Orphfix products, and the preferred diameter is 1.5 mm. Two steel needles on the left side of the fracture end face pass through the through hole of the left beam 15, and the first beam plate and the second beam plate forming the left beam 15 are fastened by screws 10. Two steel needles on the right side of the fracture end face run through the through hole of the right beam 7 . The left beam 15 or the right beam 7 are detachably connected by the first beam plate and the second beam plate through screws 10 . The length, width and height of the first beam plate and the second beam plate are 10mm, 5.5mm, and 6mm respectively, and the screw 10 is preferably a titanium alloy micro screw with a diameter of 2.6mm produced by Johnson & Johnson.

Left crossbeam 15 is fixed with left connecting block 1 by connecting screw 6, and right crossbeam 7 is fixed with right connecting block 5 by connecting screw 6, and the other end of left connecting block 1 is equipped with left strut 2, and the right end of left strut 2 is provided with Protrusion 11. The other end of the right connecting block 5 is equipped with a right pole 4, and the outside of the right pole 4 is threaded, and the diameter of the thread is preferably 3.5 mm. Cooperate with the nut 14 through threads. A flexible rod is connected between the left strut 2 and the right strut 4 to increase the flexibility of the bone ends on both sides of the fracture end surface at the initial stage of fracture healing. The diameter of the flexible rod is preferably 0.5 mm. A spring 3 is sheathed outside the flexible rod, the spring is preferably a cylindrical compression spring, and the diameter of the spring wire is preferably 4.5mm. The left end of the spring 3 is placed in the first groove 12 of the protrusion 11 , and the right end of the spring 3 is placed in the second groove 13 of the nut 14 .

According to the stress difference of stem cell recruitment, differentiation and osteogenesis, in the initial stage of rat fracture healing (stem cell recruitment period), the nut 14 is adjusted to the right end of the right strut 4, and the spring 3 is in a state of free length. At this time, the overall rigidity of the fixed bracket It is about 12.6N/mm. Due to the effect of the flexible rod, the degrees of freedom on both sides of the bone section are relatively large. Under the action of rehabilitation stress, the fractured end bears the comprehensive stress of multiple directions, which is conducive to the recruitment of stem cells. One week later, the stem cells start to differentiate (differentiation period), and the nut 14 is rotated to the left along the right strut 4, the spring 3 is compressed by force, the stiffness increases, and the degrees of freedom on both sides of the bone section become smaller. At this time, the overall stiffness of the fixed bracket is about 30N/mm--35N/mm is conducive to the differentiation of stem cells into chondrocytes and osteoblasts. Two weeks later, in the later stage of healing (osteogenic stage), the nut 14 is rotated to the left along the right strut 4 to fully compress the spring, and the rigidity of the fixed bracket reaches the highest 56.3N/mm, minimizing the degrees of freedom on both sides of the bone section. Increase the stability of the broken end and facilitate the healing of the fracture.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the present application will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (5)

1. A fracture external fixation bracket with variable stiffness is characterized in that it comprises a stiffness adjustment rod, a beam and a steel needle; The stiffness adjusting rod includes a left pole and a right pole, the outside of the right pole is equipped with a nut that can rotate along the right pole, a flexible rod is connected between the left pole and the right pole, and the A spring is sheathed outside the flexible rod, one end of the spring is in contact with the right end of the left strut, and the other end of the spring is in contact with the left end of the nut; By operating the nut to move along the right pole, the nut and the left pole can compress the spring to different degrees, so that the spring can produce different degrees of lateral stiffness, thereby changing the overall stiffness of the fixed bracket; The left pole is fixedly connected to the left crossbeam, the right pole is fixedly connected to the right crossbeam, the left crossbeam and the right crossbeam are respectively connected with steel needles, and the steel needles protrude from the lower ends of the left crossbeam and the right crossbeam. 2. A fracture external fixation bracket with variable stiffness as claimed in claim 1, wherein the right end of the left strut is provided with a protruding part, and the right end surface of the protruding part is provided with a button for positioning the left end of the spring. first groove. 3. A fracture external fixation bracket with variable stiffness according to claim 2, characterized in that, the left end surface of the nut is provided with a second groove for positioning the right end of the spring. 4. A fracture external fixation bracket with variable stiffness according to claim 1, wherein the spring is a cylindrical compression spring. 5. A fracture external fixation bracket with variable stiffness according to claim 1, characterized in that, the left beam or the right beam comprises a first beam plate and a second beam plate that cooperate with each other, and the first beam After the plate and the second beam plate are assembled, a through hole is left in the middle, the steel needle passes through the through hole, and the first beam plate and the second beam plate are detachably connected by screws.