JP2002360599A - Screw for bone coapatation having escape preventive function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw for preventing the entire part of the screw from deviating downward and causing a pain when a fracture portion is invaginated by bone coapatation using the screw. SOLUTION: The screw is formed of a structure which is capable of separating a screw end and a screw body and inserting both to each other and sliding both with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw for joining a fracture or an osteotomy in the field of medical orthopedics, and is used, for example, for a medial fracture of a femoral neck.

[0002]

2. Description of the Related Art In this type of orthopedic surgery, osteosynthesis is performed using a hollow screw 1 as shown in FIG. 1 for, for example, a medial fracture of a femoral neck.

In the osteosynthesis using the hollow screw 1, a fracture 3 of a femur 2 is fixed with the hollow screw 1 as shown in FIG.

[0004]

The above-mentioned fixing method has a problem that requires a solution as described below.

[0005] In the osteosynthesis using the hollow screw 1, as shown in FIG. 3, the fractured portions 3 of the femur 2 may be invaded with each other, and the invaginated portion 4 may be formed.

At this time, since the entire screw is shifted downward, the rear end of the screw protrudes, and a protrusion 5 is formed.

[0005] The protrusion 5 causes the hollow screw 1
Sometimes squeezed the thigh skin 6 and caused pain.

Accordingly, the present invention solves the above-mentioned problems of the prior art and reduces the possibility that the projecting portion 5 is formed, so that the hollow screw 1 can press the thigh skin 6 and cause pain. To provide a less prone osteosynthesis screw.

[0008]

The osteosynthesis screw according to the present invention has a structure in which an originally integral hollow screw is separated into a screw tip portion and a screw body portion, which can be inserted into each other and slide with each other. ing. For this reason, when the fractured parts 3 are mutually invaginated and a force acting to generate the invaginated part 4 is applied, the fractured part 3 slides between the screw tip part and the screw body part. Thereby, it is possible to suppress a phenomenon in which the entire screw is displaced downward and the rear end of the screw protrudes to form the protruding portion 5.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The osteosynthesis screw according to the present invention will be described below in detail based on a preferred embodiment of the present invention.

The osteosynthesis screw of the first embodiment has a structure in which the screw tip 7 can be inserted into the screw body 8 as shown in FIG. The screw tip 7 has a thread 9 for fixing the bone. Further, in order to prevent the screw body portion 8 from being easily displaced from the femur, the thread portion 1 which can be fixed to the femoral cortical bone is provided.
There is 0. The screw tip 7 and the screw body 8 have a hollow structure for inserting a guide wire for the insertion.

In the screw for osteosynthesis of the second embodiment, as shown in FIG. 5, after the screw tip 7 is inserted into the screw body 8, the screw tip 7 deviates from the screw body 8 toward the screw tip. To prevent this, a protrusion 11 for preventing departure is provided at the rear end of the screw tip 7, and a protrusion 12 for preventing departure at the tip of the screw body 8.

The osteosynthesis screw of the third embodiment has a compression screw 13 for drawing the screw tip 7 and the screw body 8 of the first embodiment as shown in FIG. The compression screw 13 has a thread portion 14 and a screw head 15, and the thread portion 14 is configured to be screwed into the thread portion 16 of the screw tip 7.
On the other hand, the screw body 8 has a projection 17. Compression screw 13
Is screwed into the thread portion 14, the screw head 15
Since the protrusion 17 cannot be exceeded, the screw tip 7
Is drawn to the screw body portion 8.

FIG. 7 shows an example of an operation having the above configuration.
After the operation, even if the invaginated portion 4 occurs in the fracture of the femur 2, one is that the screw tip 7 slides in the screw body 8, and the other is that the thread 10 is the cortical bone of the femur 2. 3 does not have a protrusion as shown in FIG.

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various modifications within the scope of the gist.

[0015]

As is clear from the above description, the screw for osteosynthesis according to the present invention can prevent skin pain due to protrusion of the screw.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a conventional hollow screw.

FIG. 2 is an explanatory view of a conventional hollow screw.

FIG. 3 is an explanatory view of a conventional hollow screw.

FIG. 4 is an explanatory diagram of the first embodiment of the present invention.

FIG. 5 is an explanatory view of a second embodiment of the present invention.

FIG. 6 is an explanatory view of a third embodiment of the present invention.

FIG. 7 is an explanatory diagram of the use of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow screw 2 Femur 3 Fracture part 4 Depressed part 5 Projection part 6 Skin 7 Screw tip part 8 Screw body part 9 Thread part 10 Thread part 11 Projection part 12 Projection part 13 Compression screw 14 Thread part 15 Screw head 16 Thread 17 Projection

Claims (5)

[Claims] An osteosynthesis screw having a departure prevention function according to the present invention comprises a screw tip and a screw body, and the screw tip can be inserted into the screw body and slide into each other after insertion. The screw thread is cut at the screw tip, and the screw thread is cut at the base of the screw body. The screw tip and the screw body have a hollow structure for passing a guide wire. 2. A screw head according to claim 1, wherein the screw tip can be inserted into the screw body, and slides with each other after the insertion, and the screw tip has a thread. Although it is an osteosynthesis screw, the screw thread may not be cut off at the base of the screw body, and the screw tip and the screw body may not have a hollow structure. 3. The device according to claim 1, wherein when the screw tip is inserted into the screw body, the screw tip does not deviate from the screw body toward the screw tip. Those with protrusions. 4. The method as set forth in claim 1, 2 or 3, wherein
After inserting the screw tip into the screw body, a screw for fracture compression for pulling the bone fixed by the screw tip toward the screw body can be inserted. The screw for compressing the fractured part is screwed into the compression screw thread inside the screw tip and fixed.However, at this time, the screw head of the compression screw is turned from the screw protrusion by the compression projection of the screw body, so that the screw tip is The fixed bone is drawn toward the screw body. 5. The method according to claim 1, wherein the screw tip is not inserted into the screw body, but the screw body is inserted into the screw tip.