Disposable intramedullary device for temporary use for treatment of limb infections

Abstract

A disposable intramedullary device for temporary use for treatment of limb infections comprising a solid core of variable cross-section, including a distal portion, a middle portion and a proximal portion, said proximal portion and distal portion including anchoring regions consisting of through-holes being passed through by bone anchoring means. Outside said anchoring regions, said solid core is coated with a polymer layer which also includes antibiotic, the outer diameter of the solid core and polymer layer assembly being equivalent to that of an intramedullary channel, and the outer diameter of said solid core in said anchoring regions being equivalent to that of said intramedullary channel.

Claims

1. A disposable intramedullary device for temporary use for treatment of limb infections comprising a solid core of variable cross-section, including a distal portion, a middle portion and a proximal portion, the proximal portion and the distal portion comprising anchoring regions comprising through-holes for being passed through by anchoring screws, wherein the solid core is coated with a polymer layer including antibiotic outside the anchoring regions and is not coated with the polymer layer including antibiotic in the anchoring regions, the outer diameter of the device is equivalent to that of an intramedullary channel, the diameter of the solid core in the anchoring regions equals the outer diameter of the device, and the diameter of the solid core outside the anchoring regions is smaller than the diameter of the solid core in the anchoring regions such that the outer diameter of the device outside of the anchoring regions remains equivalent to the diameter of the intramedullary channel.

2. The device according to claim 1, wherein the polymer layer including antibiotic has a thickness up to 3 mm.

3. The device according to claim 1, wherein outside the anchoring regions, the cross-section of the solid core is circular.

4. The device according to claim 1, wherein the solid core is helically surrounded by a solid element of small section to contribute to the integrity of the polymer layer including antibiotic arranged thereon.

5. The device according to claim 4, wherein the section of the solid element is one or more of circular or polygonal.

6. The device according to claim 4, wherein the solid element is a wire.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For the sake of clarity, the invention will now be described in more detail with reference to the following figures that are included as a way of example and in accordance with preferred embodiments, namely:

(2) FIG. 1 is a perspective view of the intramedullary device of the present invention.

(3) FIG. 2 is an embodiment of the intramedullary device of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) FIG. 1 is a perspective view of the device of the present invention. Said Figure illustrates a solid core 1, preferably metallic, of variable cross-section, having a distal portion 2, a middle portion 3, and a proximal portion 4. Anchoring regions 5 consisting of through-holes 6 are observed in both proximal portion 2 and distal portion 4, said through-holes being passed through by bone anchoring means, more specifically anchoring screws (not illustrated). Outside said anchoring regions 5, said solid core 1 is coated with a polymer layer 7 which also includes an antibiotic. Said layer is obtained through a specific die, and the mixture of polymer and antibiotic drains in those regions of the solid core other than the anchoring regions 5. The preferred thickness of said polymer and antibiotic layer is up to 3 mm.

(5) On the other hand, in said anchoring regions 5, only the outer diameter of said solid core 1 is equivalent to the diameter of an intramedullary channel, since there is no such polymer and antibiotic layer 7 coating the same. This offers two advantages: 1) it ensures that the regions coated with said polymer and antibiotic layer will not slide axially (as it may occur with a cover); and 2) it ensures maximum resistance to tensile and torsional mechanical stresses (shear stresses) in the anchoring regions.

(6) Subsequently, outside said anchoring regions 5, wherein said solid core 1 is indeed coated with said polymer and antibiotic layer 7, the outer diameter of said solid core 1 is slightly smaller, and of circular section, the outer diameter of the core 1 and layer 7 assembly being equivalent to that of the intramedullary channel. The section of said solid core 1, wherein it is covered with said polymer and antibiotic layer 7, is circular (generally, it is an annular section), allowing the device of the invention to keep its deformation without losing its shearing strength.

(7) FIG. 2 illustrates a particular embodiment of the intramedullary device 1 of the present invention. In particular, the solid core 1 is surrounded, preferably helically surrounded, by a solid element, e.g. a wire, of small section that is preferably circular and/or polygonal, to contribute to the integrity of the polymer and antibiotic layer 7 disposed thereon. This ensures that, in case of impact, the polymer and antibiotic layer 7 may smash, but it will remain joined to the solid element helically arranged given its particular geometry.