Title of Invention	"INTRAMEDULLARY NAIL"
Abstract	The intramedullary nail (1) has A) a distal end (2) suitable for insertion in the medullary space, wherein the segment of the intramedullary nail (1) facing the distal end (2) has a diameter D, B) a proximal end (3), C) a central longitudinal axis (4); and D) several cross holes (5) with a hole axis (6), each of which defines a virtual drill cylinder (8) with a cylinder axis (9) corresponding to the hole axis (6) of the defining cross hole (5), wherein E) the drill cylinders (8) of at least two cross holes (5) penetrate each other. The cylinder axes (9) of the two mutually penetrating drill cylinders (8) do not have any common intersection point P on the longitudinal axis (4). This results in improved mechanical strength compared to the state of the art, without any need for the size of the cross section of the intramedullary nail to be increased

Title of Invention

"INTRAMEDULLARY NAIL"

Abstract

The intramedullary nail (1) has A) a distal end (2) suitable for insertion in the medullary space, wherein the segment of the intramedullary nail (1) facing the distal end (2) has a diameter D, B) a proximal end (3), C) a central longitudinal axis (4); and D) several cross holes (5) with a hole axis (6), each of which defines a virtual drill cylinder (8) with a cylinder axis (9) corresponding to the hole axis (6) of the defining cross hole (5), wherein E) the drill cylinders (8) of at least two cross holes (5) penetrate each other. The cylinder axes (9) of the two mutually penetrating drill cylinders (8) do not have any common intersection point P on the longitudinal axis (4). This results in improved mechanical strength compared to the state of the art, without any need for the size of the cross section of the intramedullary nail to be increased

Full Text	The invention relates to an intramedullary nail in accordance with the generic term of Patent Claim 1, specifically for the distal tibia. The state of the art already includes intramedullary nails that have two intersecting cross holes at the same height, so that the same intramedullary nail can be used both for a right and for a left tubular bone. The disadvantages of this prior known arrangement is that the two (or even more) holes intersect and their axis of intersection lies on the longitudinal axis of the nail, with the result that a relatively large quantity of material is taken from the cross section of the intramedullary nail, which in turn leads to considerable mechanical weakening of the intramedullary nail at this point. The invention is intended to remedy this situation. The invention is based on the problem of creating an intramedullary nail with two (or more) intersecting cross holes that has improved mechanical strength compared to the state of the art described above, but which does not require the size of the cross section of the intramedullary nail to be increased. The invention solves the specified task by providing an intramedullary nail having the features of Claim 1. One variation of this invention is that the cylinder axes of the two mutually penetrating drill cylinders meet at an intersection point P which is at a distance d > 0 from the longitudinal axis. The distance d relative to the diameter D of the intramedullary nail is advantageously in the range 0.0001 D One further variation is that the cylinder axes of the two mutually penetrating drill cylinders are slanted and have as shortest distance the length x > 0. The length x in this system should be less than half the total of the two diameters of the mutually penetrating drill cylinders to enable the two drill cylinders to be penetrated. The section S of the length x representing the shortest distance between the two slanted cylinder axes can run parallel or at an angle to the longitudinal axis and have a shortest distance y > 0. The distance y is advantageously less than D/2, but greater than 0.4 D. In a further embodiment, the cylinder axes of the two mutually penetrating drill cylinders lie in a level orthogonal to the longitudinal axis. In another embodiment, the cylinder axes of the two mutually penetrating drill cylinders are in contrast in one level that is penetrated by the longitudinal axis at an angle a, wherein 0° In a further embodiment, the cylinder axes of the two mutually penetrating drill cylinders intersect at an angle ß, wherein 30° In a preferred embodiment, the mutually penetrating drill cylinders are provided with two separate entrance points into the intramedullary nail, but only one common exit from the intramedullary nail. The advantage of this system compared to one with 4 openings is that this system has less material loss, i.e. greater strength of the intramedullary nail. The diameter DB of the mutually penetrating drill cylinders advantageously measures at most 0.6 times, but preferably at most 0.5 times of D. In a further embodiment, the intramedullary nail is provided with a longitudinal hole coaxial to the central longitudinal axis. The bigger the diameter is of this hollow relative to the diameters of the drill cylinders, the greater can be the angle between the mutually penetrating cross holes, without any impairment to the cross section area of the intramedullary nail, i.e. without any lessening of the strength of the intramedullary nail. The invention and refinements of the invention are described in more detail in the following on the basis of partially schematic illustrations of several embodiments. Fig. 1 shows a front and rear view of the intramedullary nail with two intersecting cross holes; Fig. 2 shows a front view of the intramedullary nail with a schematic, perspective view of the drill cylinders; Fig. 3 shows an orthogonal cross section through the intramedullary nail according to Fig. 2 in the range of the intersecting cross holes; and Fig. 4 shows a schematic perspective view of two mutually penetrating drill cylinders with slanted cylinder axes. The intramedullary nail illustrated in figures 1 to 3 is provided with a distal end 2 suitable for insertion in the medullary space of a tubular bone, a proximal end 3, a central longitudinal axis 4 and two cross holes 5 with a hole axis 6, each of which defines a virtual drill cylinder 8 with a cylinder axis 9 corresponding to the hole axis 6 of the defining cross hole 5. The intramedullary nail has generally a constant diameter D and a longitudinal hole 10 coaxial to the central longitudinal axis 4. As illustrated in Fig. 3, the drill cylinders 8 of the two cross holes 5 penetrate each other, wherein the cylinder axes 9 of the two mutually penetrating drill cylinders 8 intersect at point P, which is at a distance d = 0.4 D from the longitudinal axis 4. In other words, the point P does not lie on the longitudinal axis 4 of the intramedullary nail. The mutually penetrating drill cylinders 8 are provided with two separate entrance points in the intramedullary nail 1, but only one common exit from the intramedullary nail 1. The cylinder axes 9 of the two mutually penetrating drill cylinders 8 are placed in a level orthogonal to the longitudinal axis 4, corresponding to the plane of projection of Fig. 3. The cylinder axes 9 of the two mutually penetrating drill cylinders 8 can, however, also be in one level, which is penetrated by the longitudinal axis 4 at a defined angle a (Fig. 2). In the illustrated example, the cylinder axes 9 of the two mutually penetrating drill cylinders 8 intersect at an angle ß of 60°. The diameter DB of the mutually penetrating drill cylinders 8 measures in the illustrated example 0.3 times D. As illustrated in Fig. 4, the cylinder axes 9 of the two mutually penetrating drill cylinders 8 in an alternative embodiment can also run in slanted direction and have a shortest distance 11 of the defined length x, which is smaller than half the total of the two diameters of the mutually penetrating drill cylinders 8. The section S of the length x representing the shortest distance 11 between the two slanted cylinder axes 9 runs in the illustrated example parallel to the longitudinal axis 4 and has a shortest distance y > 0. The section S can, however, also run slanted in relation to the longitudinal axis 4. The distance y is in the range of D/2 > y > 0.4 D. We claim 1. Intramedullary nail (1) with A) a distal end (2) suitable for insertion into the medullary space, wherein the segment of the intramedullary nail (1) facing the distal end (2) has a diameter D; B) a proximal end (3); C) a central longitudinal axis (4); and D) several cross holes (5) with a hole axis (6), each of which defines a virtual drill cylinder (8) with a cylinder axis (9) corresponding to the hole axis (6) of the defining cross hole (5), wherein E) the drill cylinders (8) of at least two cross holes (5) penetrate each other, F) the cylinder axes (9) of the two mutually penetrating drill cylinders (8) have no common intersection point P on the longitudinal axis (4) characterised in that G) the cylinder axes (9) of the two mutually penetrating drill cylinders (8) lie in a plane orthogonal to the longitudinal axis (4). 2. Intramedullary nail (1) as claimed in claim 1, wherein the cylinder axes (9) of the two mutually penetrating drill cylinders (8) intersect at an intersection point P, which is at a distance d > 0 from the longitudinal axis (4). 3. Intramedullary nail (1) as claimed in claim 1, wherein the cylinder axes (9) of the two mutually penetrating drill cylinders (8) are slanted and have a shortest distance (11) of length x > 0. 4. Intramedullary nail (1) as claimed in claim 3, wherein the length x is less than half the total of the two diameters of the mutually penetrating drill cylinders (8). 5. Intramedullary nail (1) as claimed in claim 3 and 4, wherein the section S of the length x representing the shortest distance (11) between the two slanted cylinder axes (9) runs parallel or at an angle to the longitudinal axis (4) and has a shortest distance y > 0. 6. Intramedullary nail (1) as claimed in claim 5, wherein the distance y is less than D/2. 7. Intramedullary nail (1) as claimed in claim 5 and 6, wherein the distance y is greater than 0.4 D. 8. Intramedullary nail (1) as claimed in claim land 2 wherein the, cylinder axes (9) of the two mutually penetrating drill cylinders (8) intersect at an angle ß, wherein 30° 9. Intramedullary nail (1) as claimed in claim 1, 2, and 8 wherein the distance d relative to the diameter D lies in the range 0.0001 D 10. Intramedullary nail (1) as claimed in claim 1 to 8, wherein the mutually penetrating drill cylinders (8) are provided with two separate entrance points into the intramedullary nail (1), but only one common exit from the intramedullary nail (1). 11. Intramedullary nail (1) as claimed in claim 1 to 10, wherein the diameter DB of the mutually penetrating drill cylinders (8) measures at most 0.6 times, and preferably at most 0.5 times D. 12. Intramedullary nail (1) as claimed in claim 1 to 10, wherein it is provided with a longitudinal hole (10) coaxial to the central longitudinal axis (4).

Full Text

The invention relates to an intramedullary nail in accordance with the generic term of Patent Claim 1, specifically for the distal tibia.
The state of the art already includes intramedullary nails that have two intersecting cross holes at the same height, so that the same intramedullary nail can be used both for a right and for a left tubular bone.
The disadvantages of this prior known arrangement is that the two (or even more) holes intersect and their axis of intersection lies on the longitudinal axis of the nail, with the result that a relatively large quantity of material is taken from the cross section of the intramedullary nail, which in turn leads to considerable mechanical weakening of the intramedullary nail at this point.
The invention is intended to remedy this situation. The invention is based on the problem of creating an intramedullary nail with two (or more) intersecting cross holes that has improved mechanical strength compared to the state of the art described above, but which does not require the size of the cross section of the intramedullary nail to be increased.
The invention solves the specified task by providing an intramedullary nail having the features of Claim 1.
One variation of this invention is that the cylinder axes of the two mutually penetrating drill cylinders meet at an intersection point P which is at a distance d > 0 from the longitudinal axis. The distance d relative to the diameter D of the intramedullary nail is advantageously in the range 0.0001 D One further variation is that the cylinder axes of the two mutually penetrating drill cylinders are slanted and have as shortest distance the length x > 0. The length x in this system should be less than half the total of the two diameters of the mutually penetrating drill cylinders to enable the two drill cylinders to be penetrated. The section

S of the length x representing the shortest distance between the two slanted cylinder axes can run parallel or at an angle to the longitudinal axis and have a shortest distance y > 0. The distance y is advantageously less than D/2, but greater than 0.4 D.
In a further embodiment, the cylinder axes of the two mutually penetrating drill cylinders lie in a level orthogonal to the longitudinal axis.
In another embodiment, the cylinder axes of the two mutually penetrating drill cylinders are in contrast in one level that is penetrated by the longitudinal axis at an angle a, wherein 0° In a further embodiment, the cylinder axes of the two mutually penetrating drill cylinders intersect at an angle ß, wherein 30° In a preferred embodiment, the mutually penetrating drill cylinders are provided with two separate entrance points into the intramedullary nail, but only one common exit from the intramedullary nail. The advantage of this system compared to one with 4 openings is that this system has less material loss, i.e. greater strength of the intramedullary nail.
The diameter DB of the mutually penetrating drill cylinders advantageously measures at most 0.6 times, but preferably at most 0.5 times of D.
In a further embodiment, the intramedullary nail is provided with a longitudinal hole coaxial to the central longitudinal axis. The bigger the diameter is of this hollow relative to the diameters of the drill cylinders, the greater can be the angle between the mutually penetrating cross holes, without any impairment to the cross section area of the intramedullary nail, i.e. without any lessening of the strength of the intramedullary nail.
The invention and refinements of the invention are described in more detail in the

following on the basis of partially schematic illustrations of several embodiments.
Fig. 1 shows a front and rear view of the intramedullary nail with two intersecting cross holes;
Fig. 2 shows a front view of the intramedullary nail with a schematic, perspective view of the drill cylinders;
Fig. 3 shows an orthogonal cross section through the intramedullary nail according to Fig. 2 in the range of the intersecting cross holes; and
Fig. 4 shows a schematic perspective view of two mutually penetrating drill cylinders with slanted cylinder axes.
The intramedullary nail illustrated in figures 1 to 3 is provided with a distal end 2 suitable for insertion in the medullary space of a tubular bone, a proximal end 3, a central longitudinal axis 4 and two cross holes 5 with a hole axis 6, each of which defines a virtual drill cylinder 8 with a cylinder axis 9 corresponding to the hole axis 6 of the defining cross hole 5. The intramedullary nail has generally a constant diameter D and a longitudinal hole 10 coaxial to the central longitudinal axis 4.
As illustrated in Fig. 3, the drill cylinders 8 of the two cross holes 5 penetrate each other, wherein the cylinder axes 9 of the two mutually penetrating drill cylinders 8 intersect at point P, which is at a distance d = 0.4 D from the longitudinal axis 4. In other words, the point P does not lie on the longitudinal axis 4 of the intramedullary nail. The mutually penetrating drill cylinders 8 are provided with two separate entrance points in the intramedullary nail 1, but only one common exit from the intramedullary nail 1. The cylinder axes 9 of the two mutually penetrating drill cylinders 8 are placed in a level orthogonal to the longitudinal axis 4, corresponding to the plane of projection of Fig. 3. The cylinder axes 9 of the two mutually penetrating drill cylinders 8 can, however, also be in one level, which is penetrated by the longitudinal axis 4 at a defined angle a (Fig. 2).
In the illustrated example, the cylinder axes 9 of the two mutually penetrating drill

cylinders 8 intersect at an angle ß of 60°.
The diameter DB of the mutually penetrating drill cylinders 8 measures in the illustrated example 0.3 times D.
As illustrated in Fig. 4, the cylinder axes 9 of the two mutually penetrating drill cylinders 8 in an alternative embodiment can also run in slanted direction and have a shortest distance 11 of the defined length x, which is smaller than half the total of the two diameters of the mutually penetrating drill cylinders 8. The section S of the length x representing the shortest distance 11 between the two slanted cylinder axes 9 runs in the illustrated example parallel to the longitudinal axis 4 and has a shortest distance y > 0. The section S can, however, also run slanted in relation to the longitudinal axis 4. The distance y is in the range of D/2 > y > 0.4 D.

We claim
1. Intramedullary nail (1) with
A) a distal end (2) suitable for insertion into the medullary space, wherein the segment of the intramedullary nail (1) facing the distal end (2) has a diameter D;
B) a proximal end (3);
C) a central longitudinal axis (4); and
D) several cross holes (5) with a hole axis (6), each of which defines a virtual drill cylinder (8) with a cylinder axis (9) corresponding to the hole axis (6) of the defining cross hole (5), wherein
E) the drill cylinders (8) of at least two cross holes (5) penetrate each other,
F) the cylinder axes (9) of the two mutually penetrating drill cylinders (8) have no
common intersection point P on the longitudinal axis (4)
characterised in that
G) the cylinder axes (9) of the two mutually penetrating drill cylinders (8) lie in a
plane orthogonal to the longitudinal axis (4).
2. Intramedullary nail (1) as claimed in claim 1, wherein the cylinder axes (9) of the two
mutually penetrating drill cylinders (8) intersect at an intersection point P, which is at a
distance d > 0 from the longitudinal axis (4).
3. Intramedullary nail (1) as claimed in claim 1, wherein the cylinder axes (9) of the two mutually penetrating drill cylinders (8) are slanted and have a shortest distance (11) of length x > 0.
4. Intramedullary nail (1) as claimed in claim 3, wherein the length x is less than half the total of the two diameters of the mutually penetrating drill cylinders (8).
5. Intramedullary nail (1) as claimed in claim 3 and 4, wherein the section S of the
length x representing the shortest distance (11) between the two slanted cylinder axes
(9) runs parallel or at an angle to the longitudinal axis (4) and has a shortest distance y > 0.

6. Intramedullary nail (1) as claimed in claim 5, wherein the distance y is less than D/2.
7. Intramedullary nail (1) as claimed in claim 5 and 6, wherein the distance y is greater than 0.4 D.
8. Intramedullary nail (1) as claimed in claim land 2 wherein the, cylinder axes (9) of the two mutually penetrating drill cylinders (8) intersect at an angle ß, wherein 30° 9. Intramedullary nail (1) as claimed in claim 1, 2, and 8 wherein the distance d relative to the diameter D lies in the range 0.0001 D
10. Intramedullary nail (1) as claimed in claim 1 to 8, wherein the mutually penetrating drill cylinders (8) are provided with two separate entrance points into the intramedullary nail (1), but only one common exit from the intramedullary nail (1).
11. Intramedullary nail (1) as claimed in claim 1 to 10, wherein the diameter DB of the mutually penetrating drill cylinders (8) measures at most 0.6 times, and preferably at most 0.5 times D.
12. Intramedullary nail (1) as claimed in claim 1 to 10, wherein it is provided with a longitudinal hole (10) coaxial to the central longitudinal axis (4).

Documents:

3544-DELNP-2005-Abstract-(28-11-2008).pdf

3544-delnp-2005-abstract.pdf

3544-delnp-2005-assignment.pdf

3544-DELNP-2005-Claims-(28-11-2008).pdf

3544-delnp-2005-claims.pdf

3544-DELNP-2005-Corresopndence-Others-(28-11-2008).pdf

3544-DELNP-2005-Correspondence-Others-(04-03-2008).pdf

3544-DELNP-2005-Correspondence-Others-(12-12-2007).pdf

3544-delnp-2005-correspondence-others.pdf

3544-delnp-2005-descriprion (complete).pdf

3544-DELNP-2005-Description (Complete)-(28-11-2008).pdf

3544-DELNP-2005-Drawings-(28-11-2008).pdf

3544-delnp-2005-drawings.pdf

3544-DELNP-2005-Form-1-(28-11-2008).pdf

3544-delnp-2005-form-1.pdf

3544-delnp-2005-form-13-(04-03-2008).pdf

3544-delnp-2005-form-18.pdf

3544-DELNP-2005-Form-2-(28-11-2008).pdf

3544-delnp-2005-form-2.pdf

3544-DELNP-2005-Form-26-(04-03-2008).pdf

3544-DELNP-2005-Form-3-(28-11-2008).pdf

3544-delnp-2005-form-3.pdf

3544-delnp-2005-form-5.pdf

3544-delnp-2005-form-6.pdf

3544-delnp-2005-gpa.pdf

3544-delnp-2005-pct-210.pdf

3544-delnp-2005-pct-308.pdf

3544-delnp-2005-pct-409.pdf

3544-delnp-2005-petition-138.pdf

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Patent Number

228322

Indian Patent Application Number

3544/DELNP/2005

PG Journal Number

07/2009

Publication Date

13-Feb-2009

Grant Date

31-Jan-2009

Date of Filing

09-Aug-2005

Name of Patentee

SYNTHES GMBH

Applicant Address

EIMATTSTRASSE 3, CH-4436 OBERDORF, SWITZERLAND.

Inventors:

#	Inventor's Name	Inventor's Address
1	ANDRE SCHLIENGER	TUNNELWEG 16, CH-4142 MUNCHENSTEIN, SWITZERLAND
2	MARKUS BUETTLER	IM RANK 199, CH-4717 MUMLISWIL SWITZERLAND
3	PETER SENN	BURGMATTSTRASSE 18, CH-4437 WALDENBURG, SWITZERLAND

PCT International Classification Number

A61B 17/72

PCT International Application Number

PCT/CH2003/000184

PCT International Filing date

2003-03-21

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	PCT/CH2003/000184	2003-03-21	Switzerland