BIORESORABLE FIXATION NAIL

Abstract

The invention relates to a fixation nail for temporarily securing transplantable tissue, bone parts, and bone replacement substances using a cover or for securing natural or artificial bone replacement parts to bones. The fixation nail has a round flat nail head with a diameter of 0.50 to 6.0 mm, and the thickness of the nail head is 0.10 to 2.0 mm. The fixation nail has a nail pin which is formed with a sharp tip, and the pin has a length between 0.5 times to 2 times the diameter of the nail head and a thickness between 0.15 times to 0.5 times the diameter of the nail head. The fixation nail consists of a biocompatible, biocorrodable magnesium alloy which is composed of at least 90 wt. % metal magnesium and contains less than 0.1 wt. % aluminum, less than 0.1 wt. % copper, less than 0.1 wt. % iron, and less than 0.1 wt. % nickel as physiologically undesirable impurities.

Claims

1. A fixing nail (1) for temporary attachment of transplantable tissue, bone parts and bone replacement substances by means of covering or for attachment of natural and artificial bone replacement parts to bones, comprising a round and flat nail head (2) having a diameter of 1.5 to 4.0 mm and wherein the thickness of the nail head (2) is 0.4 to 1.0 mm wherein the fixing nail (1) has a nail pin (3) designed with a sharp tip, the length of said nail pin being 0.5 times to 2 times the diameter of the nail head, and the pin thickness of said nail pin being between 0.15 times and 0.5 times the diameter of the nail head, wherein the fixing nail (1) consists of a biocompatible, biocorrodable magnesium alloy composed of at least 90 wt. % metallic magnesium and less than 0.1 wt. % aluminium, less than 0.1 wt. % copper, less than 0.1 wt. % iron and less than 0.1 wt. % nickel as physiologically undesired impurities.

2. The fixing nail (1) according to claim 1, wherein the fixing nail (1) has a round and flat nail head (2) having a diameter of preferably 2.5 mm, and wherein the thickness of the nail head (2) is preferably 0.6 mm and the fixing nail (1) has a nail pin (3) designed with a sharp tip, the length of said nail pin being preferably 2.4 mm, and the pin thickness of said nail pin being a maximum of 0.8 mm.

3. The fixing nail according to claim 1 wherein the nail pin (3) has at least one barb.

4. The fixing nail according to claim 1, wherein the nail pin (3) has one or two barbs in the region of the lower half of the pin length.

5. The fixing nail (1) according to claim 1, the fixing nail (1) consists of a biocorrodable magnesium alloy composed of at least 80 wt. % metallic magnesium, a zinc proportion of 0.1 to 3.0 wt. %, a zirconium proportion of 0.1 to 3.0 wt. %, a rare earth metals proportion totaling 0.1 to 10.0 wt. % and less than 0.1 wt. % aluminium, less than 0.1 wt. % copper, less than 0.1 wt. % iron and less than 0.1 wt. % nickel as physiologically undesired impurities, wherein the rest is 100 wt. % magnesium.

6. The fixing nail (1) according to claim 1 wherein the nail pin (3) has at least one bulge of 0.1 to 0.3 mm in the region of the lower third of the fixing pin.

7. The fixing nail (1) according to claim 1 wherein the nail pin (3) has at least one, preferably 2 to 5 groove-like constrictions or groove-like milled portions (6) of 0.1 to 0.2 mm.

8. The fixing nail (1) according claim 1, wherein the nail head (2) is designed in a hooded manner (7).

9. The fixing nail (1) according to claim 1 wherein the tip of the nail pin (3) is designed in a harpoon-shaped manner (4).

10. The fixing nail (1) according to claim 1 wherein the tip of the nail pin (3) is designed in a lanceolate manner (5).

Description

[0043] The invention in question will be described in greater deal by way of the following figures.

[0044] FIG. 1 shows the fixing nail according to the invention having a harpoon-shaped tip of the nail pin.

[0045] FIG. 2 shows the fixing nail according to the invention having a lanceolate tip of the nail pin.

[0046] FIG. 3 shows the fixing nail according to the invention having grooves in the nail pin.

[0047] FIG. 4 shows the fixing nail according to the invention having a hooded nail head.

[0048] FIG. 5 shows a detailed drawing of a magnesium nail according to the invention for use in dentistry.

[0049] FIG. 6 shows a three-dimensional representation of the magnesium nail according to the invention as per FIG. 5.

[0050] FIGS. 1 to 6 each show an embodiment of the fixing nail (1) according to the invention. This consists of a nail head (2) and a nail pin (3). The tip of the nail pin (3) can be harpoon-shaped (4) (FIG. 1) or lanceolate (5) (FIG. 2) in order to ensure stable anchoring in the bone.

[0051] The nail pin (3) can also be provided with grooves (6) over the entire length or a part of its length (FIG. 3), particularly in order to improve the initial anchoring in the bone and to prevent any unwanted extraction.

[0052] The tearing of the nail head through the anchored covering membrane is prevented by the head of the nail, which is broad in relation to the length of the pin. The nail head must also have sufficient mechanical stability and must not bend when the nail is driven in. The nail head can be hooded (7) (FIG. 4).

[0053] FIGS. 5 and 6 show a typical embodiment of the magnesium nail according to the invention which has been trialled within the clinic. A particularly suitable embodiment of the invention is shown in FIG. 5. The magnesium nail outlined there in a CAD drawing is characterised by a nail head of 2.5 mm in diameter and a material thickness of 0.7 mm. The nail pin is characterised by a length of 2.4 mm and a material thickness of 0.7 mm. The nail pin has a milled portion of 0.1 mm in the middle to form a barb approximately. The nail head has bevels on the edge which makes it easier to grip the pin with the applicator. FIG. 6 shows the magnesium nail according to the invention in a three-dimensional view. This magnesium nail is particularly suitable for use in bone augmentation in the course of dental implantations.

[0054] When using magnesium nails according to the invention, particularly a nail according to FIG. 5 and FIG. 6, all clinical requirements are fulfilled. The physiological safety of magnesium as a biocorrodable metal is known from other studies (Schrenk, Sebastian, Abbauverhalten degradierbarer Magnesiumlegierungen in korperahnlichen Flussigkeiten, Dissertation, Medizinische Fakultat der Friedrich-Alexander-Universitat Erlangen-Nurnberg 2011).

LIST OF REFERENCE SYMBOLS

[0055] 1. Fixing nail

[0056] 2. Nail head

[0057] 3. Nail pin

[0058] 4. Harpoon-shaped tip of the nail pin

[0059] 5. Lanceolate tip of the nail pin

[0060] 6. Grooves

[0061] 7. Hooded nail head