TWM522000U - Bone screw applicable for melt-implanting to bone correction site or diseased bone - Google Patents

Description

Suitable for hot-melt implants to bone correction or diseased bone nails

The present invention relates to a composite bone nail, and particularly to a bone nail suitable for hot melt implantation to a bone correction or diseased bone.

Polylactic acid (PLA) belongs to a thermoplastic aliphatic polyester. Polylactic acid can be decomposed in any form and release acidic products such as natural decomposition, composting, or incineration, so its related products have been widely used in different industries. For example, polylactic acid can be made into bone nails, surgical sutures, diapers, sanitary napkins, or bandages for medical use; such bone nails can be directly embedded in the body and naturally decomposed in the body, thus eliminating the need for additional A second operation is performed to remove the bone nail.

Both magnesium and its alloys are an absorbing material that can be implanted in the body and release alkaline products. Compared with other materials with the same properties, they have superior biocompatibility and mechanical properties. Based on the above characteristics, magnesium and its alloys can also be made into bone nails, but the decomposition speed of such bone nails in the body is quite rapid (about one to three months), and it may be necessary to perform two or more operations on the individual to re-implant. The bone nail can achieve the effect of fixing the diseased bone.

For examples of bone nails combined with polylactic acid and magnesium (or magnesium alloy), refer to the Chinese Utility Model Bulletin No. CN204092165U, which discloses a "high-strength combined self-degrading expanded bone nail" comprising: pure magnesium (or magnesium alloy). The bone nail body and the expanded polylactic acid internal thread cavity which is located in the body of the bone nail. The surface of the inner portion of the inner surface cone of the expanded polylactic acid internal thread cavity is a deep thread, and the surface of the front portion is a shallow thread; the outer surface of the expanded polylactic acid internal thread cavity has a plurality of surfaces 70 to 90 A trapezoidal or inverted triangle wedge. The bone body is a cone with a narrow head and a wide tail, and its appearance The middle part of the face cone has a deep thread, the front part is a shallow thread, and the nail cap of the bone nail body is provided with an inner triangle or a slotted cavity communicating with the bone nail body, and the bone nail body is located in the expansion type when used. In the lactic acid internal thread cavity. However, due to the structure of the conventional nail, it cannot be implanted into the bone correction or diseased bone of the individual by hot melt implantation. Moreover, since magnesium (or magnesium alloy) is not completely coated in the present case, the degradation rate of magnesium (or magnesium alloy) in the body is much faster than the degradation rate of polylactic acid in the body (about half a year to one year), The mechanical properties of magnesium (or magnesium alloy) cannot be exhibited in the body. In addition, in the previous example, the magnesium material and the polylactic acid cavity were tightly fixed by means of screw tight fitting, and the polylactic acid cavity was forced to be pressed during operation due to the polymerization. When a lactic acid material is added to a calcium phosphate-based material to form a composite material, the brittleness of the polylactic acid material increases, so that when it is subjected to press-fitting, brittle fracture occurs, and the broken bone cannot be effectively fixed. Therefore, the polylactic acid material used in the previous example cannot be applied to a polylactic acid complex having an added bone growth promoter such as a hydroxide apatite and a calcium phosphate salt, so that the conventional bone nail has clinical application and therapeutic effect. Subject to considerable restrictions.

It is a well-known technique to soften the polylactic acid bone nail by hot melt and compress it into a preset bone cavity for fixation. The method is to place the heat source above the polylactic acid bone nail and soften the nail by heating. So that the nail can enter the preset bone cavity. However, because of the poor thermal conductivity of polylactic acid, the size of such bone nails is greatly limited, and its length usually cannot exceed 0.5 cm. Furthermore, the strength of the polylactic acid bone nail is not good, so it cannot be applied to the load-bearing area.

One of the purposes of this creation is to propose a novel composite absorbable bone nail which can be applied to a polylactic acid outer cavity doped with a ceramic filler such as an inorganic salt, and is hot-melt implanted to the bone correction or Diseased bones.

In order to achieve the above and/or other purposes, the present invention proposes a bone nail suitable for hot melt implantation of polylactic acid doped with a ceramic filler such as an inorganic salt to a bone correction or diseased bone, which comprises: a polylactic acid or The polylactic acid is doped with a ceramic filler coating such as an inorganic salt, and a magnesium metal block, and the magnesium metal block is disposed in the polylactic acid coating layer without being exposed.

And, in order to achieve the above and/or other purposes, the present invention proposes a bone nail suitable for hot-melt implantation to a bone correction or diseased bone, comprising: a polylactic acid or a polylactic acid doped with a ceramic filler such as an inorganic salt. a coating layer; and a magnesium alloy block disposed in the polylactic acid coating layer without being exposed.

According to the high thermal conductivity of the magnesium metal and the magnesium alloy, the two bone nails can be rapidly thermally conductive through the absorbable magnesium metal material during hot melt implantation, so that the size of the absorbable bone nail of the hot melt implant is not limited. In order to increase the therapeutic purpose for use, and to enhance the clinical application value of this absorbable bone nail. In addition, regardless of whether the magnesium metal block or the magnesium alloy block is not exposed in the polylactic acid coating layer, after the hot melt implantation, the polylactic acid or the polylactic acid coating layer doped with the ceramic filler such as an inorganic salt It must be decomposed first than the magnesium metal block or the magnesium alloy block, so that the mechanical properties of the magnesium metal block or the magnesium alloy block can be exhibited at the bone correction or the diseased bone to withstand the bone correction or the diseased bone. weight. In this way, not only can the avoidance of re-surgical implantation of the nails be avoided, but also the bone correction or the bone fixation can be assisted to engage the reduction.

According to paragraph [0008], the polylactic acid of the present invention or the polylactic acid doped with a ceramic filler such as an inorganic salt may have an acidic product when it is degraded, and the magnesium metal and the magnesium alloy of the present invention are alkaline when degraded. The product is produced, and the two products will produce a chemical reaction that neutralizes the acid to form a harmless inorganic salt.

(1)‧‧‧ bone nails

(2) ‧‧‧ polylactic acid coating

(3) ‧‧‧Magnesium-containing metal blocks

(4) ‧ ‧ bulging

(A) ‧ ‧ Orthopedic or sick bone

(B) ‧ ‧ pre-drilled holes

(C)‧‧‧Supersonic vibration heating probe

(D) ‧‧‧ trabecular space

1 is a perspective view showing a bone nail of one embodiment of the present invention.

Figure 2 is a cross-sectional view showing the above nail.

Figures 3 to 5 illustrate the process of hot-melt implantation of the above-mentioned bone nails to the site where bone correction or disease is required.

In order to make the above and/or other objects, functions and features of the present invention more obvious and easy to understand, the following is a detailed description of the preferred embodiments:

Referring to Figures 1 and 2, a bone nail (1) of one embodiment of the present invention is illustrated. The bone nail (1) can be hot melt implanted into a bone correction or diseased bone (A), which has the following composition: a polylactic acid coating layer (2), and a magnesium-containing metal block (3); wherein the magnesium-containing metal block (3) is disposed in the polylactic acid coating layer (2) without being exposed, wherein The distance from the top of the magnesium metal block (3) to the top of the polylactic acid coating layer (2) is between 0.1 mm and 5 mm. In particular, the term "not exposed" in this document means that an object is completely covered in another object, and that any one end, any area is covered by the covered object is not exposed. It can be seen that any end or region of the magnesium-containing metal block (3) is covered by the polylactic acid coating layer (2) and is not exposed. In addition, in order to adapt to different types of bone correction or diseased bone (A) at different treatment sites, the polylactic acid coating layer (2) may optionally be added with other absorbable biological materials, such as hydroxyapatite (hydroxyapatite, HAP), β-tricalcium phosphate (β-TCP), calcium polyphosphate (CPP). In addition, polylactic acid can be replaced by gelatin, polyethylene glycol (PEG), polycaprolactone (PCL), lactic acid-ethylene glycol copolymer, polydioxanone ( Polydioxanone, PDO), or chitin. Moreover, examples of the magnesium-containing metal block (3) may be, but not limited to, magnesium metal blocks or magnesium. Alloy block. Further, examples of the polylactic acid coating layer (2) may be, but not limited to, polylactic acid or a polylactic acid coating layer (2) doped with a ceramic filler such as an inorganic salt.

In the case of hot-melt implantation, a pre-drilled hole (B) having a smaller diameter than the heat-fusible bone nail (B), a polylactic acid coating layer (2) may be preset in the bone correction or the diseased bone (A). The outer surface may be provided with a concavo-convex shape, for example, having a plurality of projections (4) or not having irregularities. In addition, since the magnesium-containing metal block (3) has high thermal conductivity properties, the outer surface of the magnesium-containing metal block (3) may be irregular or pre-set nano or micro-holes to increase the heat transfer area. Through this design, the efficiency of heat conduction to the polylactic acid coating layer (2) can be accelerated by the increase of the contact area between the magnesium-containing metal block (3) and the polylactic acid coating layer (2) during the hot melt implantation process. With the distance, the polylactic acid coating layer (2) is accelerated and softened and penetrated into the trabecular space.

Referring to Figures 3 to 5, the process of hot-melt implantation of the bone nail (1) of the present embodiment to the bone correction or diseased bone (A) is further illustrated:

As shown in Fig. 3, a pre-drilled hole (B) having a diameter smaller than the diameter of the absorbable bone nail of the present invention is preset between the bone correction site or the diseased bone (A), and the front part of the bone nail (1) is placed. The smaller diameter tip portion is placed in the pre-drilled hole (B).

As shown in FIG. 4, the probe (C) is heated by a device such as ultrasonic wave, but is not limited thereto, and the end of the bone nail (1) is heated relative to the pre-drilled hole (B) and pressed downward. .

As shown in FIG. 5, when heated, the polylactic acid coating layer (2) is partially softened, and the softened bone is heated by a heat source such as an ultrasonic vibration heating probe to fill the pre-drilled hole with softened polylactic acid. (B) Flowing into the trabeculae void (D) in the bone correction or diseased bone (A). In addition, when partially softened, the polylactic acid coating layer (2) may also flow to the magnesium-containing metal block (3), infiltrate into the surface of the magnesium metal block, and closely match the magnesium metal material.

After heating, the polylactic acid coating layer (2) can be coagulated to the trabecular bone in the bone correction or diseased bone (A) and closely matched with the magnesium-containing metal block (3). In this way, the bone nail (1) of the present embodiment achieves the purpose of fixing the bone correction or the diseased bone (A).

In summary, through the high thermal conductivity of magnesium metal and magnesium alloy, the bone nail of the present invention can rapidly conduct heat during hot melt implantation, so that the size of the nail is not limited, so as to increase the applicable bone correction and disease. The type of bone and the clinical value of the nail. In addition, regardless of whether the magnesium metal block or the magnesium alloy block is not exposed to the polylactic acid or the polylactic acid coating layer doped with a ceramic filler such as an inorganic salt, the polylactic acid or the inorganic substance is added after the hot melt implantation. The polylactic acid coating layer of ceramic fillers such as salt is decomposed first than the magnesium metal block or the magnesium alloy block, so that the time of the magnesium metal block or the magnesium alloy block is increased in the body, and the degradation rate of the pure magnesium metal bone nail is solved too fast. The problem is that the mechanical properties of the magnesium metal block or the magnesium alloy block can be exhibited in the bone correction or the diseased bone to withstand the weight that the bone correction and the diseased bone originally have to bear. In this way, not only can the avoidance of re-surgical implantation of the nails be avoided, but also the bone correction and the bone fixation can be assisted to engage the reduction.

However, the above is only a preferred embodiment of the present invention, but it is not intended to limit the scope of the present invention; therefore, the simple equivalent changes and modifications made by the scope of the patent application and the contents of the new manual are All are still covered by this creation patent.

(2) ‧‧‧ polylactic acid coating

(3) ‧‧‧Magnesium-containing metal blocks

(4) ‧ ‧ bulging

Claims (10)

A bone nail suitable for hot melt implantation into a bone correction or diseased bone, comprising: a polylactic acid coating layer; and a magnesium metal block disposed in the polylactic acid coating layer without being exposed. The bone nail of claim 1, wherein the surface of the magnesium metal block is concave and convex. The bone nail of claim 1, wherein a distance from a top of the magnesium metal block to a top of the polylactic acid coating layer is between 0.1 mm and 5 mm. The nail according to claim 1, wherein the outer surface of the polylactic acid coating layer is provided with a concavo-convex shape. The bone nail according to claim 1, wherein the polylactic acid coating further comprises hydroxyapatite (HAP), β-tricalcium phosphate (β-TCP), and poly Calcium phosphate (CPP). A bone nail suitable for hot-melt implantation to a bone correction or diseased bone, comprising: a polylactic acid or a polylactic acid coating layer doped with a ceramic filler such as an inorganic salt; and a magnesium alloy block, which is not exposed The ground layer is disposed in the polylactic acid coating layer. The bone nail of claim 6, wherein the surface of the magnesium alloy block is concave and convex. The nail according to claim 6, wherein a distance from a top of the magnesium alloy block to a top of the polylactic acid coating layer is between 0.1 mm and 5 mm. The nail according to claim 6, wherein the polylactic acid coating layer is provided with a concavo-convex shape with respect to an outer surface of the magnesium alloy block. The bone nail according to claim 6, wherein the polylactic acid coating layer further comprises hydroxyapatite, β-tricalcium phosphate, and calcium polyphosphate.