JP2615322B2 - Intraosseous fixation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intraosseous fixation body used for fixation of bone in the treatment of bone diseases such as bone fracture and osteonecrosis.

[0002]

2. Description of the Related Art Screws have been frequently used for fixing two bones to be joined in the treatment of a bone disease such as a fracture. The screw is inserted into the bone and interconnects and fixes two or more bone parts. Recently, a sliding screw and a cannulated screw have also been used. Here, the sliding screw is
It is composed of a screw and an outer cylinder for receiving the root of the screw. The screw can slide in the outer cylinder. The screw and sleeve are inserted into the bone and interconnect the two parts. The screw is movable only in the axial direction of the outer cylinder, and prevents the gap from being formed between the connected portions by sliding the screw in the outer cylinder.

[0003] The cannulated screw has almost the same shape as a normal screw, but has a small hole through the center axis of the screw for passing a steel wire. It is used to insert into bone and connect two or more parts together. When inserting,
A thin steel wire is inserted first, and after confirming that the steel wire enters a target portion, a cannulated screw is inserted using the steel wire as a guide, and then the steel wire is removed.

[0004]

However, conventional screws and the like have a problem that bone deformation may occur after fixation. That is, bone is composed of hard bone tissue and soft bone marrow tissue, blood circulates inside, and each cell is nourished. Trabecular bone is a solid structure of calcium-containing fine mesh-like bone tissue in bones.
Since these are continuously connected, the mechanical strength of the bone (particularly, the epiphysis) is maintained. In a fracture, the trabecular bone is broken at the fracture, and the bone splits into two or more parts (bone fragments). For the fracture to heal, it is necessary for the trabecular bone to be reconnected and regained continuity by biological repair. The tissue involved in the repair usually invades the fracture from each bone fragment. Internal fixatives are used to secure the bone during such repair processes.

However, since the conventional internal fixation material is a solid type, the repair process is performed only on the bones outside the internal fixation material,
The larger the inner fixation material, the smaller the healing portion. Also, in a fracture near a joint, a blood vessel entering a bone fragment on the joint surface side is damaged, and this bone fragment loses blood flow, and cells may die to become necrotic bone. In this case, the trabecular bone in the bone fragment (necrotic bone) on the joint surface side is in a dead state. The repair tissue reaches the fracture from the bone fragment on the side opposite to the joint surface, heals the fracture, and further enters the necrotic bone to regenerate it. However, during the process of necrotic bone regeneration, the resorption of dead trabeculae may occur before the formation of new trabeculae, which may be mechanically weak. Therefore, since a structural defect surface is formed inside the fracture (necrotic bone) on the joint surface side, the joint surface may be depressed and deformed into a landslide after the fracture is healed. In this case, the compatibility of the joint surface is lost, and joint devastation is inevitable. That is, the fracture has healed, but the joint function is impaired.

[0006] In addition, there is a disease called osteonecrosis in which some cells of the bone die and become necrotic bone. There is an interface between living bone and necrotic bone, and repair tissue invades from living bone to necrotic bone and regenerates the bone. In necrotic bone trabeculae, cells are dead, but the trabecular structure is continuous with living bone trabeculae, maintaining the same strength as before necrosis. However, during the regeneration process, if the dead trabecular bone is resorbed by the repair tissue, that part becomes mechanically weak. When this disease occurs near a joint, the joint surface may be depressed or deformed and the joint may be devastated in a process similar to the case of the above-described fracture near the joint. The present invention has been made in view of the above-mentioned problems of the related art, and an object of the present invention is to provide an intraosseous fixation body that efficiently fixes two bone parts to each other and prevents occurrence of bone deformation after the fixation. It is in.

[0007]

According to the present invention, there is provided an intraosseous fixation device comprising:
A side wall portion is a continuous body capable of preventing penetration of bone tissue accompanying bone growth, and a cylindrical body having a threaded portion formed on an outer portion of the side wall portion, the cylindrical body being a boundary portion between two bone tissues. When embedded in the cylindrical body, the threaded portion at one end of the cylindrical body is configured to be screwed into one bone tissue, and the threaded portion at the other end is capable of screwing into the other bone tissue. At the same time, both ends of the cylindrical body are opened so that the one bone tissue can be inserted from one end of the cylindrical body until the other bone tissue substantially abuts each other from the other end. It is characterized by the following.
That is, in the treatment of a bone disease such as a fracture or osteonecrosis, the endosseous fixation body of the present invention is inserted into the bone and fixes the two parts, and simultaneously, the two parts of the bone to be fixed are inserted into and out of the cylinder. The purpose of this is to make bones exist inside the inner fixation material. The intraosseous fixation body is composed of a metal, a synthetic resin, a composite material, or the like. The outer shape of the cross section is circular or polygonal, and a part or all of its outer wall is provided with a thread.

[0008]

According to the intraosseous fixation device of the present invention,
First, the area of bone involved in healing increases. Second, the bone inside the tube also contributes to the fixation, thus increasing the stability of the fixation. Third, when there is a necrotic bone due to a fracture or osteonecrosis near the joint, collapse and deformation of the joint surface can be prevented. In other words, by inserting the tubular intraosseous fixation body at the boundary between living bone and necrotic bone, the living bone, boundary surface (fracture surface), and necrotic bone are divided into the inside and outside of the intraosseous fixation body, respectively. You. On this occasion,
The operation of inserting the intraosseous fixation blocks the blood flow inside the intraosseous fixation. For this reason, among the living bones, bones inside the intraosseous fixation body become necrotic bones. Therefore,
The boundary between the living bone and the necrotic bone is different from that before the insertion, and a portion extending in a columnar shape to the side of the living bone is added to form a mushroom-like shape. For this reason, the fragile portion formed inside the necrotic bone during the repair process is not a simple surface as in the case where the intraosseous fixation body is not inserted, and collapse and deformation such as landslide are unlikely to occur. Also, during the repair process, the fragile portions that occur outside the endosseous fixation are supported by the fixation forces of the endosseous fixation and the necrotic bone inside the endosseous fixation. By such an action, the mechanical strength of the necrotic bone during the repair process is maintained, and the collapse and deformation of the joint surface are prevented.

[0009]

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of the cylindrical intraosseous fixation body of the present invention. In the figure, an intraosseous fixation body 11 is cylindrical and has upper and lower ends 12 and 13 open, and a thread 14 is provided on the outer side over the entire length. Next, an example of treating a fracture using the intraosseous fixation device according to the present embodiment will be described. That is, when connecting two bone parts, first, a groove 5 corresponding to the intraosseous fixation body 11 is dug from one side of the fracture surface 4 with a cylindrical drill or a cylindrical chisel in one bone fragment 2 of the fracture (FIG. 2). . Subsequently, a similar groove 5 is dug in the other bone fragment 3 from the fracture surface 4 side (FIG. 3). Next, the tubular intraosseous fixation body 11 is screwed or driven into the groove 5 of the one bone fragment 2 from the fracture surface 4 (FIG. 4). Finally, the tubular intraosseous fixation body 11 is screwed or driven into the groove 5 of the other bone fragment 3 from the fracture surface 4,
The bone fragments 2 and 3 on both sides are fixed (FIG. 5). In the case of osteonecrosis 6 (the hatched portion in FIG. 6), a hole is made from the outside of the bone fragment 7 (in the direction of arrow 9 in FIG. 7), passes through the normal bone, crosses the boundary surface 8, and the necrotic bone Dig a groove 5 reaching 6 (FIG. 7). There, a tubular intraosseous fixation member is screwed or driven in the direction of arrow 9 so as to straddle the bones 6 and 7 on both sides of the boundary surface 8 (FIG. 8). FIG. 9 shows an intraosseous fixation body 1 according to this embodiment.
Reference numeral 1 denotes a state in which the bone fragments 2 and 3 are joined and fixed. The partition 10 may be provided inside the cylinder of the fixed body 11 (FIG. 10).

[Brief description of the drawings]

FIG. 1 is a perspective view of a tubular endosseous fixation material according to the present invention.

FIG. 2 is a schematic perspective view showing a state in which a groove corresponding to an internal fixation material is dug in one bone fragment of a fracture.

FIG. 3 is a perspective view showing a state where a groove corresponding to an internal fixation material is dug in the other fracture of the fracture.

FIG. 4 is a perspective view showing a state where an intraosseous fixation material is inserted into one bone fragment of a fracture.

FIG. 5 is a perspective view showing a state in which a fracture is fixed with a tubular intraosseous fixation material.

FIG. 6 is a perspective view of an osteonecrotic bone.

FIG. 7 is a perspective view of a state where a groove crossing a boundary surface of osteonecrosis is dug from the outside (lower surface) of the bone.

FIG. 8 is a perspective view when an intraosseous fixation body is used for osteonecrosis.

FIG. 9 is a schematic view showing a state where a bone fragment is fixed using the intraosseous fixation body shown in FIG. 1;

FIG. 10 is a perspective view of an intraosseous fixation body having a partition therein.

[Explanation of symbols]

 2 ... one bone fragment of a fracture 3 ... the other bone fragment of a fracture 4 ... fracture surface 5 ... a groove dug inside the bone 6 ... necrotic bone (hatched) 7 ... normal bone 8 ... Boundary surface 9 ... Arrow indicating direction of digging groove 10 ... Partition wall 11 ... Cylindrical bone fixation body

Claims (2)

(57) [Claims] 1. A side wall is a continuous body capable of preventing penetration of bone tissue accompanying bone growth, and a cylindrical body having a threaded portion formed on an outer portion of the side wall. When inserted and embedded in the boundary portion of the bone tissue, the threaded portion at one end of the cylindrical body and one bone tissue,
The screw portion on the other end side is configured to be screwable with the other bone tissue, and the one bone tissue from one end of the cylindrical body is connected to the other bone tissue from the other end. An intraosseous fixation, wherein both ends of the tubular body are opened so that bone tissues can be inserted until they substantially abut each other. 2. The intraosseous fixation according to claim 1, wherein the one bone tissue is a living bone tissue and the other bone tissue is a necrotic bone tissue.