Assembly comprising an implantable part designed to be fastened to one or more bones or bone portions to be joined, and at least one screw for fastening the implantable part to said bone(s)

Abstract

An assembly including an implantable part designed to be fastened to at least one bone or bone portions to be joined and at least one screw for fastening the implantable part to the at least one bone or bone portions. The implantable part includes at least one tapped hole and the screw includes a head designed to be engaged in the tapped hole. The tapped hole is cylindrical and includes at least one radial notch emerging in a surface of the implantable part through which the screw is designed to be engaged in the tapped hole. The radial notch produces an interruption in the tapping included by the tapped hole. The head of the screw is conical, with an apical angle of between 15 and 25°.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an assembly comprising an implantable part designed to be fastened to one or more bones or bone portions to be joined, and at least one screw for fastening the implantable part to said bone(s). Said implantable part may in particular be a fastening base for fastening part of a joint prosthesis to a bone, in particular a fastening base for fastening a glenoid to shoulder blade in a total shoulder prosthesis; the implantable part may also be a cortical plate or any other piece of arthrodesis or osteosynthesis equipment.BACKGROUND OF THE INVENTION[0002]It is well known to use screws to fasten implantable parts such as bases used to fasten joint prosthesis components or cortical or similar plates serving to perform an arthrodesis or osteosynthesis of one or more bones.[0003]A very traditional base or plate comprises smooth cylindrical holes in which the fastening screws are designed to be engaged. Each hole may be adjusted to ...

AI Technical Summary

Benefits of technology

The patent text describes the design of a screw used in orthopedic surgery that has multiple possible directions of implantation. This design is achieved through a notch in the hole, a specific conical shape of the screw head, and the lack of narrow engagement between the screw and hole during the initial stages of screwing. These features allow for slight deformation of the screw at the notch and complete interlocking with the hole at the end of the screwing process. The text also suggests that this design can prevent the screw from emerging at a joint surface of one or more treated bones, reducing the risk of defective implantation.

Problems solved by technology

In the first case, the base of the plate has the drawback of imposing an implantation direction on the screw and therefore prohibiting implantation directions other than that which is imposed.

Such assemblies also have the drawback of imposing an implantation direction on the screw determined by said engagement.

Furthermore, such assemblies have a noteworthy risk of unscrewing of one or more screws over time under the effect of the repeated forces undergone by the bone(s).

To resolve this risk of unscrewing, various axial retention systems have been designed for the screws, which, in general, have the drawbacks of being relatively expensive to manufacture and not always being very effective.

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