Extrusion type expansion anchor

Abstract

The invention relates to an extrusion type expansion anchor. The extrusion type expansion anchor comprises an anchor body and an expansion element, wherein a notch is formed in a position near the front end of the anchor body, the expansion element is used for being inserted into an inner cavity of the anchor body from the rear end of the anchor body to enable the front end of the anchor body to expand in the radial direction, and an annular groove A is formed in the inner side wall of the anchor body; the expansion element is of a columnar structure, and an annular protrusion B is arranged onthe side wall of the expansion element; and the annular groove A and the annular protrusion B are matched with each other to achieve retaining clamping fit. According to the extrusion type expansionanchor, the anti-pulling force of the anchor body is increased by adopting a self-locking expansion structure, so that the anchor body is not prone to falling off after being implanted into a bone, the number of elements used for anchoring outside the anchor body does not need to be increased, and the circumstance that the overall operation time is influenced due to the fact that the anchor is difficult to knock in or the screwing-in time is long is avoided; and meanwhile, a one-way self-locking structure of the anchor body and the expansion element is formed by utilizing the retaining clamping fit of the annular groove A and the annular protrusion B, so that the expansion element is not prone to loosening after being extruded into the anchor body, the expansion element does not need to have high shear strength, and the expansion element can be suitable for an absorbable material and a PEEK material.

Description

technical field [0001] The invention belongs to the technical field of bone implantation anchors, and relates to an extruded expansion anchor. Background technique [0002] Anchors are mainly used clinically for tendon soft tissue injuries such as shoulder joints and knee joints. By implanting the anchors in the bone hole, the torn tendon tissue is fixed on the bone with sutures, so as to achieve tendon-bone healing. Purpose, since the human joint is active for a long time, the stability of its implantation in the bone is particularly important. [0003] Most of the existing knock-in and screw-in anchors simply rely on the extrusion and anchoring between the teeth on the outside of the anchor body and the inner wall of the bone hole to provide anti-pullout force. The force must require a sufficient number of teeth, which makes it difficult to drive the anchor in or takes a long time to screw in, which affects the overall operation time. [0004] Patent CN201520214267.0 dis...

AI Technical Summary

Problems solved by technology

[0003] The existing knock-in and screw-in anchors simply rely on the extrusion and anchoring between the teeth on the outside of the anchor body and the inner wall of the bone hole to provide pull-out resistance. Since the outer diameter of the anchor is fixed, in order to improve pull-out The force inevitably requires a sufficient number of teeth, which makes it difficult to knock in the anchor or takes a long time to screw in, which affects the overall operation time

[0004] Patent CN201520214267.0 discloses an anchor, which uses the expansion of the head diameter of the anchor body to increase the extrusion force between the anchor body and the bone hole, thereby enhancing the pull-out resistance of the anchor, and internal expansion The number of thread teeth of the element is less, which reduces the operation time required for screwing in the expansion element, and reduces the overall time and difficulty of the operation to a certain extent. However, for polymer materials such as absorbable and PEEK materials, the main body of the anchor is used The design of the contact convex point for anchoring with the bone hole leads to poor fixation strength, and the screw-in bolt expansion element has a higher requirement for the shear strength of the bolt, resulting in high polymers such as absorbable and PEEK materials. The material is easy to be twisted during implantation. In addition, during the operation, the screw-in implantation method is more complicated and difficult to operate than the knock-in implantation method, which prolongs the operation time and increases the difficulty of the operation.

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