Absorbable interface anchor

Abstract

The utility model relates to the technical field of medical instruments, in particular to an absorbable interface anchor which is made of polylactic acid composite materials and comprises a sleeve and an extrusion pin, the sleeve is arranged to be of a radial expandable structure, and convex teeth are arranged on the outer wall of the sleeve; the outer diameter of the lower end of the extrusion pin is smaller than the inner diameter of the sleeve, the outer diameter of the upper end of the extrusion pin is larger than the inner diameter of the sleeve, and the sleeve expands outwards in the radial direction when the extrusion pin is pushed into the sleeve. The interface anchor is arranged to be radially expandable, and the outer diameter of the interface anchor can be larger than the inner diameter of the bone tunnel, so that the fixing strength of the interface anchor in the bone tunnel is improved. Meanwhile, the friction force of the interface anchor in the bone tunnel is increased through the convex teeth on the outer wall of the sleeve, and therefore the fixing strength of the interface anchor is further improved.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to an absorbable interface anchor. Background Technology

[0002] Interface anchors are commonly used implantation devices in sports medicine orthopedic surgery, suitable for the reattachment of ligaments, tendons, or soft tissues to bone during knee cruciate ligament reconstruction surgery. The procedure involves: under arthroscopic guidance, a bone tunnel is drilled at the target location in the tibia and femur; the transplanted tissue is then compressed and fixed to the inner wall of the bone tunnel using the interface anchor; and the body's self-healing mechanism allows the tissue to eventually achieve biological fusion with the bone tunnel.

[0003] Currently, interfacial anchors are made of three types of materials: titanium alloy, polyetheretherketone (PEEK), and absorbable polylactic acid composite materials. Under the same structural design, different materials have their own advantages and disadvantages in terms of fixation strength and biocompatibility: Titanium alloy interfacial anchors have excellent mechanical properties, and their high material strength ensures strong fixation after implantation into the bone tunnel. However, because the material is non-absorbable, it needs to remain in the body for a long time, and a very small number of patients may experience foreign body reactions. PEEK anchors perform well in terms of biocompatibility and chemical stability, and their fixation strength is between that of titanium alloy and absorbable materials. However, their non-absorbability means they need to remain in the body for a long time. Although absorbable polylactic acid composite anchors avoid secondary surgery, their mechanical properties are lower than the former two, resulting in a significant disadvantage in fixation strength and a risk of dislodgement, especially for patients with osteoporosis, where the risk of dislodgement is even higher.

[0004] Therefore, under the same structural design, the fixation strength of the three types of materials is: titanium alloy > PEEK > polylactic acid composite material. The contradiction between the properties of these materials and clinical needs is particularly evident in the field of absorbable materials—they must meet bioabsorbability requirements while overcoming the risk of fixation failure due to insufficient mechanical strength. Therefore, developing interfacial anchors that combine excellent initial fixation strength with absorbability is a pressing technical problem that needs to be solved. Summary of the Invention

[0005] To solve the above-mentioned technical problems, this utility model provides an absorbable interface anchor that is both absorbable by the human body and has great fixing strength.

[0006] The technical solution provided by this utility model is as follows:

[0007] An absorbable interfacial anchor made of polylactic acid composite material, comprising:

[0008] A sleeve, wherein the sleeve has a slit that runs along the length of the sleeve and penetrates its side wall, the slits are arranged in several rows from one end of the sleeve to the other end, each row contains several evenly spaced slits, and the slits in adjacent rows are staggered, and the outer wall of the sleeve is provided with protruding teeth.

[0009] The extrusion pin has a lower outer diameter smaller than the inner diameter of the sleeve and an upper outer diameter larger than the inner diameter of the sleeve. The extrusion pin is pushed into the sleeve along the axial direction, and the sleeve expands radially outward.

[0010] Preferably, the surface of the extrusion pin has a rough surface structure.

[0011] Preferably, the lower end of the extrusion pin is tapered or bullet-shaped.

[0012] Preferably, the polylactic acid composite material is a polylactic acid / bioactive glass composite material.

[0013] The beneficial effects of this invention are as follows: by making the interface anchor radially expandable, the outer diameter of the interface anchor can be larger than the inner diameter of the bone tunnel, thereby increasing the fixation strength of the interface anchor within the bone tunnel. Simultaneously, the protruding teeth on the outer wall of the sleeve increase friction, further enhancing the fixation strength of the interface anchor within the bone tunnel. This invention's interface anchor is particularly suitable for clinical applications where osteoporosis patients require higher fixation strength. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the interface anchor of this utility model when it is not expanded;

[0015] Figure 2 This is a schematic diagram of the expanded interface anchor of this utility model.

[0016] In the diagram, 1 is a sleeve, 11 is a slot, 12 is a tooth, and 2 is a pressing pin. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the absorbable interface anchor of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings, so as to better understand the structure and working principle of this utility model. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit this utility model.

[0018] In this utility model, unless otherwise stated, the orientations used, such as "up" and "down", usually refer to the direction shown in the accompanying drawings, or to the vertical, perpendicular, or gravitational direction; similarly, for ease of understanding and description, "left" and "right" usually refer to the left and right shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0019] like Figures 1-2As shown, the absorbable interface anchor of this invention mainly consists of two parts: a sleeve 1 and a compression pin 2. Both the sleeve 1 and the compression pin 2 are made of polylactic acid composite material, preferably polylactic acid / bioactive glass composite material. This material has good biocompatibility and absorbability, and can gradually degrade in the human body, avoiding the need for secondary surgery for removal.

[0020] The sleeve 1 has slits 11 arranged along its length on its side wall, penetrating the side wall of the sleeve 1. The slits 11 are arranged in several rows from one end of the sleeve 1 to the other end, with each row consisting of several evenly spaced slits 11. The slits in adjacent rows are staggered. This design allows the sleeve 1 to expand radially more easily when subjected to external forces. The outer wall of the sleeve 1 has protruding teeth 12, which can increase the friction between the sleeve 1 and the inner wall of the bone tunnel, thereby improving the fixation strength of the interface anchor in the bone tunnel.

[0021] The lower outer diameter of the extrusion pin 2 is smaller than the inner diameter of the sleeve 1, and the upper outer diameter of the extrusion pin 2 is larger than the inner diameter of the sleeve 1. During the process of the extrusion pin 2 being pushed into the sleeve 1, the extrusion pin 2 extrudes the sleeve 1, causing the slit 11 on the sleeve 1 to deform and open laterally, resulting in the radial expansion of the sleeve 1.

[0022] In order to allow the extrusion pin 2 to be smoothly pushed into the sleeve 1, the lower end of the extrusion pin 2 is designed as a cone or bullet.

[0023] To increase the friction between the extrusion pin 2 and the sleeve 1, the surface of the extrusion pin 2 is roughened. This helps ensure that the extrusion pin 2 can effectively squeeze the sleeve 1 during the insertion process, causing it to undergo the expected radial expansion.

[0024] In order to expand the sleeve 1 radially, the length of the extrusion pin 2 is greater than the length of the sleeve 1.

[0025] In use, first insert the sleeve 1 of the interface anchor into the pre-drilled bone channel; then, push in the extrusion pin 2, whose tapered lower end can smoothly enter the sleeve 1. As it continues to push in, the upper end of the extrusion pin 2 begins to radially extrude into the sleeve 1, causing the slot 11 to deform and expand (e.g., Figure 2 The slit 11 shown increases the outer diameter of the sleeve 1, creating an interference fit with the bone channel. Simultaneously, the protruding teeth 12 on the sleeve 1 enhance the friction with the inner wall of the bone channel. This synergistic effect of the interference fit and friction significantly improves the fixation strength of the interface anchor within the bone channel. Because the polylactic acid composite material has a certain degree of elasticity and the sleeve 1 has limited radial expansion within the bone channel, the sleeve 1 will not crack when the extrusion pin 2 enters it. Even if the sleeve 1 cracks, the cracked sleeve remaining within the bone channel still allows the interface anchor to maintain an interference fit with the bone channel.

[0026] In summary, the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An absorbable interface anchor made of a polylactic acid composite material, characterized by, The application relates to a sleeve (1) provided with slits (11) arranged along the length direction of the sleeve (1) and penetrating the side wall of the sleeve (1), the slits (11) are arranged in several rows from one end to the other end of the sleeve (1), each row contains several slits (11) uniformly distributed, and the slits (11) in adjacent two rows are staggered, and the outer wall of the sleeve (1) is provided with convex teeth (12). An extrusion pin (2) with a lower end outer diameter smaller than the inner diameter of the sleeve (1) and an upper end outer diameter larger than the inner diameter of the sleeve (1) is pushed into the sleeve (1) along the axial direction of the sleeve (1), and the sleeve (1) is expanded radially outward. The surface of the extrusion pin (2) is a rough surface structure.

2. The absorbable interfacial anchor of claim 1, wherein, The lower end of the extrusion pin (2) is conical or bullet-shaped.

3. Absorbable interfacial anchor according to claim 1 or 2, characterized in that, The polylactic acid composite material is a polylactic acid / bioactive glass composite material.

4. The absorbable interfacial anchor of claim 1, wherein, ​

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