Patent Publication Number: US-2021186578-A1

Title: Trumpet expandable vertebral device

Description:
CROSS REFERENCE 
     The present invention claims priority to TW 108146387 filed on Dec. 18, 2019. 
     BACKGROUND OF THE INVENTION 
     Field of Invention 
     The present invention relates to a trumpet expandable vertebral device; particularly, it relates to such a trumpet expandable vertebral device which, when inserted into a human body, can radially expand itself so as to assist restoring a vertebra to its original shape. 
     Description of Related Art 
     When a human spine (e.g. cervical vertebrae, thoracic vertebrae, lumbar vertebrae, etc.) suffers a compression fracture, or collapses due to poor bone mass density, an expandable vertebral device which is inserted into the spine can help to expand the space to restore the spine to a better condition. U.S. Pat. No. 7,846,206 B2, U.S. Pat. No. 9,414,933 B2, and TW 1589266 disclose different types of expandable vertebral devices. 
     In comparison with the prior arts, the present invention provides a different mechanical structure to reduce the number of required components, whereby the manufacture and assembly of the vertebral device is much easier. 
     SUMMARY OF THE INVENTION 
     From one perspective, the present invention provides a trumpet expandable vertebral device comprising: a center shaft having a front end and a rear end; a trumpet expandable part mounted outside and surrounding the center shaft, wherein the trumpet expandable part includes: plural expandable plates, each expandable plate having a thickness which increases from the front end toward the rear end; a fixed part, surrounding and holding a predetermined portion of the center shaft, but allowing the center shaft to rotate with respect to the trumpet expandable part within the fixed part in a radial direction of the center shaft; and a connection part for connecting the trumpet expandable plates with the fixed part; a trumpet expanding ring mounted outside and surrounding the center shaft, wherein the trumpet expanding ring is located between the center shaft and the trumpet expandable part in the radial direction; wherein when the trumpet expanding ring moves toward the rear end relatively to the trumpet expandable part, the trumpet expandable plates are expanded to expand a vertebra. 
     In one embodiment, the center shaft has a main body and an exterior surface of the main body is threaded, and wherein an interior surface of the trumpet expanding ring is correspondingly threaded. 
     In one embodiment, the rear end of the center shaft is an operable end which is configured to be driven by a corresponding tool, such that the center shaft rotates within the fixed part and rotates relatively to the expandable plates. 
     In one embodiment, the operable end has a hexagonal shape. 
     In one embodiment, the trumpet expanding ring includes at least one protrusion which is configured to insert into a slit which is formed when the expandable plates are expanded, to be in contact with a side of at least one of the expandable plates. 
     In one embodiment, the center shaft includes a peripheral surface and the fixed part is mounted to press against the peripheral surface. 
     In one embodiment, the trumpet expandable vertebral device further comprises a nut which is connected to the front end of the center shaft. 
     In one embodiment, the center shaft comprises a hollow interior and is provided with an inlet and at least one outlet for the injection of a filler into a human body. 
     In one embodiment, the center shaft is provided with at least one outlet on a radial surface of the rotatable center shaft. 
     In one embodiment, each of the expandable plates has a width D, and the connection part is connected with each expandable plate by a width d, and d&lt;(1/2)D. 
     The objectives, technical details, features, and effects of the present invention will be better understood with regard to the detailed description of the embodiments below, with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a trumpet expandable vertebral device according to one embodiment of the present invention, in expanded state. 
         FIG. 2  shows the trumpet expandable vertebral device in  FIG. 1 , in disassembled state. 
         FIG. 3  shows the trumpet expandable vertebral device in  FIG. 1 , in closed state. 
         FIG. 4  shows a trumpet expandable vertebral device according to another embodiment of the present invention, in expanded state. 
         FIG. 5  shows the trumpet expandable vertebral device in  FIG. 4 , in disassembled state. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The drawings as referred to throughout the description of the present invention are for illustration only, to show the interrelations between the components, but not drawn according to actual scale of shapes and sizes. 
     Please refer to  FIGS. 1-3 , which show a trumpet expandable vertebral device according to an embodiment of the present invention (i.e. trumpet expandable vertebral device  100 ), in its expanded state ( FIG. 1 ), disassembled state ( FIG. 2 ) and closed state, respectively. The right side, in the drawings, of the trumpet expandable vertebral device  100  is the front end and the left side of the trumpet expandable vertebral device  100  is the rear end. When an surgical operation is performed to insert the trumpet expandable vertebral device  100  into a human body, the right side enters the human body first. 
     The trumpet expandable vertebral device  100 , according to the present invention, includes a center shaft  101 , a trumpet expandable part  102  and a trumpet expanding ring  103 . The trumpet expandable part  102  and the trumpet expanding ring  103  are mounted outside and surrounding the center shaft  101 . By the term “mounted”, it means that the trumpet expandable part  102  and the trumpet expanding ring  103  surround and hold the center shaft  101 , but it is not necessary for the trumpet expandable part  102  and the trumpet expanding ring  103  to be fixed to the center shaft  101 . In a radial direction of the center shaft  101 , the trumpet expanding ring  103  is located between the center shaft  101  and the trumpet expandable part  102 . The center shaft  101  has a main body and an exterior surface of the main body is threaded, and an interior surface of the trumpet expanding ring  103  is correspondingly threaded. The rear end (left side) of the center shaft  101  is an operable end  101 A; when an surgical operation is performed and the operable end  101 A is activated to rotate, the center shaft  101  is driven to rotate within the trumpet expanding ring  103  and relatively to the trumpet expanding ring  103 , whereby the center shaft  101  moves relatively to the trumpet expanding ring  103  along an axial direction of the center shaft  101  (that is, whereby the trumpet expanding ring  103  moves relatively to the center shaft  101  along the axial direction of the center shaft  101 ). In the embodiment as shown in  FIG. 2 , the operable end  101 A has a hexagonal shape, and can be driven by a tool having a corresponding shape. However, the present invention can be embodied in many other ways, as long as the operable end  101 A can be driven by a corresponding tool. 
     The trumpet expandable part  102  includes expandable plates  102 A, a fixed part  102 B and a connection part  102 C. There are plural expandable plates  102 A; each expandable plate  102 A has a thickness  102 A 1  which increases from the front end (right side of the figure) toward the rear end (left side of the figure). This thickness variation is an important feature of the present invention and will be explained in more detail later below. In the shown embodiment, the expandable plates  102 A have a rectangular shape in a projection surface which is parallel to the axial direction of the center shaft  101  and have an arc shape in another projection surface which is parallel to the radial direction of the center shaft  101 , but this is only one example and the shape of the expandable plates  102 A can be embodied in other forms. The fixed part  102 B is configured to fix a relative position of the trumpet expandable part  102  with respect to the center shaft  101  in the axial direction of the center shaft  101 , that is, so that the positional relationship between the trumpet expandable part  102  and the center shaft  101  is held stable. The relative position between the trumpet expandable part  102  and the center shaft  101  can be fixed by any feasible ways, and what is shown by the embodiment is one example. In this embodiment as shown in the drawings, the center shaft  101  includes a peripheral surface  101 B and the fixed part  102 B is mounted outside the peripheral surface  101 B of the center shaft  101 , to press against the operable end  101 A. Thus, in the axial direction of the center shaft  101 , the relative relationship between the trumpet expandable part  102  and the center shaft  101  is fixed relatively, while in the radial direction of the center shaft  101 , the center shaft  101  is able to rotate within the fixed part  102 B, relatively to the trumpet expandable part  102 . The connection part  102 C connects the expandable plates  102 A with the fixed part  102 B. 
     When an operator, such as a surgeon, drives the center shaft  101  to rotate relatively to the trumpet expanding ring  103  (which also is to rotate relatively to the trumpet expandable part  102 ), whereby the center shaft  101  move within and relatively to the fixed part  103  toward the right side, the trumpet expanding ring  103  can be driven toward the left side relatively to the trumpet expandable part  102 . Because the thickness  102 A 1  of the expandable plate  102 A is varied, such as constantly increasing from the right side of the figure toward the left side of the figure, when the trumpet expanding ring  103  is driven toward the left side relatively to the trumpet expandable part  102 , the expandable plates  102 A are expanded, achieving the function of restoring the height and shape of the vertebrae. 
     Note that “constantly increasing (from the right side of the figure toward the left side of the figure)” is only one embodiment of the present invention. Under the spirit of the present invention, the increase of the thickness can be arranged in many other ways. For example, in the shown embodiment, the thickness increase rate is substantially a constant, but in other embodiments, the thickness increase rate can be varied, or a certain portion of the expandable plate  102 A can have a constant thickness. These variations can still achieve the objective for the expandable plate  102 A to expand as the center shaft  101  rotates relatively to the trumpet expanding ring  103 . 
     Please refer to  FIG. 2 . In one preferred embodiment, the trumpet expanding ring  103  includes at least one protrusion  103 A, and more preferably, includes protrusions  103 A having a number equal to the number of the expandable plates  102 A. The protrusion  103 A is configured to be inserted into a slit which is formed between the lateral edges of the expandable plates  102 A when they are expanded, to be in contact with a side edge of a corresponding expandable plate  102 A. Thus, when the expandable plates  102 A tend to compress due to a resistance coming from human body, because the protrusion  103 A is in contact with or limited by the edges of the expandable plate  102 A, the trumpet expanding ring  103  can be held in the desired position and held not to be pushed backward according to the axial direction of the center shaft  101 . 
     In one preferred embodiment, the center shaft  101  comprises a hollow interior and is provided with an inlet and at least one outlet for the injection of a filler into a human body during a surgical operation, so that when the trumpet expandable vertebral device  100  is inserted into the human body, the filler such as bone cement or bone graft can be injected from the inlet, through the hollow interior, to outflow from the outlet into the vertebrae. In one embodiment, the filler is injected form the inlet at the left side (at the operable end  101 A) of the center shaft  101 , through the hollow interior of the center shaft  101 , to outflow out from the outlet at the right side of the center shaft  101 . Referring to  FIGS. 1 and 2 , in a more preferable embodiment, the center shaft  101  is further provided with outlets (e.g.  101 C) on its radial surface to multiply the channels for releasing the fillers, so that the filler injected form the inlet at the left side of the center shaft  101 , in addition to flowing through the hollow interior of the center shaft  101  and flowing out from the outlet at the right side of the center shaft  101 , also flows out in the radial direction from the radial outlets provided on the radial surface of the center shaft  101 . The number, size and shape of the outlets  101 C are shown as an example, not for limiting the scope of the present invention. 
     Please refer to  FIG. 2 , in one preferred embodiment, each expandable plate  102 A has a width D (i.e. the perimeter of the expandable plate  102 A in the radial surface), and the connection part  102 C is connected with each expandable plate  102 A by a width d, and d&lt;D, to reduce the required force for expanding the expandable plate  102 A. In a more preferable embodiment, d&lt;(1/2)D. 
     In one preferred embodiment, a nut  109  is fitted to or is fixed to the right side of the center shaft  101 , to prevent the trumpet expanding ring  103  from detaching from the center shaft  101 . However, if this is not a concern, the nut  109  can be omitted. 
     Please refer to  FIGS. 4-5 , which show a trumpet expandable vertebral device according to another embodiment of the present invention, in expanded state and in disassembled state, respectively. This embodiment shows that: the number of the expandable plates is not limited to two, but can be a number more than two; so is the number of the protrusions  103 A of the trumpet expanding ring  103 . Also, please refer to  FIG. 5 , the shapes and structures of the fixed part  102 B and the connection part  102 C are not limited to the shapes and structures as shown in  FIGS. 1-3 , but can be modified as desired; the spirit of the present invention is fulfilled as long as the fixed part  102 B can assist to fix the relative relationship between the trumpet expandable part  102  and center shaft  101  in the axial direction of the center shaft  101 , and the connection part  102 C allows the expandable plate  102 A to expand. 
     The present invention has been described in considerable detail with reference to certain preferred embodiments thereof. It should be understood that the description is for illustrative purpose, not for limiting the scope of the application of the present invention. An embodiment or a claim of the present invention does not need to be regarded as having to achieve all the objectives or advantages of the present invention. The title and abstract are provided for assisting searches but not for limiting the scope of the present invention. Those skilled in this art can readily conceive variations and modifications within the spirit of the disclosure in this specification, which should therefore be included in the scope of the following claim(s) made by the inventors. For example, as long as the primary objective is attained, other extra components can be added, or, components that are given separate reference numbers and described as separate items can be combined into one piece. As an example, the fixed part  102 B and the connection part  102 C can be manufactured in one piece, or be regarded as one single unit. As another example, the expandable plates do not necessary be of the shape as shown, that is, to have a rectangular shape in a projection on a surface which is parallel to the axial direction of the center shaft  101  and have an arc shape in a projection on a surface which is parallel to the radial direction of the center shaft  101 ; the expandable plates can have other shapes as long as they can be expanded by the relative rotation of the center shaft  101  within the trumpet expanding ring  103 . It is not limited for each of the embodiments described hereinbefore to be used alone; under the spirit of the present invention, two or more of the embodiments described hereinbefore can be used in combination. For example, two or more of the embodiments can be used together, or, a part of one embodiment can be used to replace a corresponding part of another embodiment. In view of the foregoing, the spirit of the present invention should cover all such and other modifications and variations, which should be interpreted to fall within the scope of the following claims and their equivalents.