Title of Invention	"INTRAMEDULLARY NAIL"
Abstract	The intramedullary nail (1) is designated in particular for the tibia and has a distal end (2) for insertion into the medullary canal, a proximal end (3), a central axis (4) and a generally rod-like shape over the hole length L. The nail (1) has three distinct locking sections (5,6,7) with at least one through-hole (8) each for receiving locking screws whereby said three locking sections (5,6,7) are separated from each other by two distinct intermediate sections (9,10) having less through-holes (8) per length unit than each of the locking sections (5,6,7).

Title of Invention

"INTRAMEDULLARY NAIL"

Abstract

The intramedullary nail (1) is designated in particular for the tibia and has a distal end (2) for insertion into the medullary canal, a proximal end (3), a central axis (4) and a generally rod-like shape over the hole length L. The nail (1) has three distinct locking sections (5,6,7) with at least one through-hole (8) each for receiving locking screws whereby said three locking sections (5,6,7) are separated from each other by two distinct intermediate sections (9,10) having less through-holes (8) per length unit than each of the locking sections (5,6,7).

Full Text	Intramedullary nail The invention relates to an intramedullary nail, in particular for the tibia, according to the preamble of claim 1. Intramedullary nails with proximal and distal locking options are already known in the art. Depending on the fracture site and the anatomical situation, in particular for the tibia bone, an additional locking option on an intermediate level would be desirable. On this point, the invention intends to provide remedial measures. The invention is based on the objective of providing an intramedullary nail having an additional locking option, in the case of a tibial nail in the area of the Isthmus. The invention solves the posed problem with an intramedullary nail that displays the features of claim 1. The three level locking according to the invention optimizes the transmission of load by different distribution and transformation of the load applied to the nail. The additional intermediate locking level (between the proximal and distal level) serves as a support or artificial additional joint and therefore will divide the load on a new lever-arm-ratio. The intermediate level locking option may also serve in mechanical principle as an (elongated) Isthmus and will be the more efficient the bigger the gap between the nail diameter and the intramedullary canal of the bone is. The various partial length of the intramedullary nail according to the invention are defined as follows: L5: proximal locking section extending from said proximal end to a distal boundary; L6: distal locking section extending from said distal end to a proximal boundary; L7 : isthmus locking section located between said distal and proximal locking sections with a proximal boundary and a distal boundary; L9 : distance between the proximal boundary of said isthmus locking section to said distal boundary of said proximal locking section. L-1o : distance of said distal boundary of said isthmus locking section to said proximal boundary of said distal locking section; and LD :distance between the distal end of the intramedullary nail to the through hole which is located nearest to said distal end. LP : distance between the proximal end of the intramedullary nail to the through hole which is located nearest to said proximal end. In a special embodiment the distinct intermediate sections of the intramedullary nail have no through-holes. This feature increases the stability in the fractured area. In a further embodiment the intramedullary nail exhibits the following features: A) a proximal locking section extending from said proximal end over the distance 0,22 L B) a distal locking section extending from said distal end over the distance 0,18 L a proximal boundary; and C) an isthmus locking section located between said distal and proximal locking sections with a proximal boundary and a distal boundary and a length of 0,08 L The advantage obtained by these features is the creation of enough space to place sufficient locking options in different directions. In a further embodiment the proximal boundary of said isthmus locking section has a distance 0,27 L In a further embodiment said distal boundary of said isthmus locking section has a distance of 0,13 L In a further embodiment the geometry of the intramedullary nail obeys to the condition: 0,32 L In a further embodiment the intramedullary nail has a first intermediate section having the length L9 between said proximal locking section and said isthmus locking section and which preferably has no through holes. This feature increases the strength of the intramedullary nail. In a further embodiment the intramedullary nail has a second intermediate section between said distal locking section and said isthmus locking section having the length L-io and which preferably has no through holes. This measure further increases the strength of the intramedullary nail. In a further embodiment the isthmus locking section has two through holes, preferably arranged at a relative angle a in the range of 60° In a further embodiment the through hole which is located nearest to said distal end of said intramedullary nail has a distance LD to said distal end in the range of 0,01 L In another embodiment the through hole which is located nearest to said proximal end has a distance LP to said proximal end in the range of 0,01 L In a further embodiment said proximal locking section having the length Lsand said first intermediate section having the length Lg are arranged at an angle ft in the range of 7° The invention and additional configurations of the invention are explained in even more detail with reference to the partially schematic illustration of several embodiments. The invention is described below on the basis of advantageous embodiments and with reference to the attached drawings in which: Fig. 1 shows, in a longitudinal view, an intramedullary nail according to the invention; Fig. 2 shows an antero-posterior (or frontal) view of a modified intramedullary nail according to the invention inserted in a schematically represented tibia bone; Fig. 3 shows the intramedullary nail of Fig. 2 in a latero-medial (or sagittal) view; Fig. 4 shows an antero-posterior (or frontal) view of an intramedullary nail according to prior art with only two level locking; Fig. 5 shows the intramedullary nail according to prior art of Fig. 4 in a latero-medial view; and Fig. 6 shows an orthogonal section of the nail according to Fig. 1 along the line VI - VI in the region of one of the locking holes. The intramedullary nail 1 shown in Fig. 1 has a distal end 2 for insertion into the medullary canal, a proximal end 3, a central axis 4 and a generally rod-like shape over the hole length L. The intramedullary nail 1 has three distinct locking sections 5,6,7. Each of these locking sections 5,6,7 has a number of through-holes 8 for receiving locking screws. Proximal locking section 5 has two through holes 8, one of which is an elongated one. Distal locking section 6 has three trough holes 8 two of which are parallel and the intermediate third through hole is running vertical to the other two. As shown in Fig. 6 the isthmus locking section 7 has two through holes 8 which are disposed at an angle a of 90°. Said three locking sections 5,6,7 are separated from each other by two distinct intermediate sections 9,10 having no through-holes 8. The proximal locking section 5 extends from said proximal end 3 of said intramedullary nail 1 over a distance L5 equal to 0,25 L in direction of said distal end 2 to a distal boundary 11. The distal locking section 6 extends from said distal end 2 over the distance Le equal to 0,2 L in direction of said proximal end 3 to a proximal boundary 12 and the isthmus locking section 7 located between said distal and proximal locking sections 5,6 with a proximal boundary 13 and a distal boundary 14 has a length of L7 equal to 0,115 L. Said proximal boundary 13 of said isthmus locking section 7 has a distance L9 equal to 0,3 L to said distal boundary 11 of said proximal locking section 5. Said distal boundary 14 of said isthmus locking section 7 has a distance LIO equal to 0,215 L to said proximal boundary 12 of said distal locking section 6. Therefore the sum of the two distances LIO+ L6 is equal to 0,415 L. The intramedullary nail 1 further has a first intermediate section 9 having the length L9 between said proximal locking section 5 and said isthmus locking section 7 and which has no through holes 8. It further has a second intermediate section 10 between said distal locking section 6 and said isthmus locking section 7 having the length LIO and which has no through holes 8. The through hole 8 which is located nearest to said distal end 2 has a distance LD to said distal end 2 which is equal at least the diameter "d" of said through hole 8. Said proximal locking section 5 having the length L5 and said first intermediate section 9 having the length Lg are arranged at an angle /? equal to 10° being the angle between the prolongation 4d of the central axis 4 in the distal locking section 6 and the central axis 4 in the proximal locking section 5. As shown in Fig. 6 the intramedullary nail 1 has a cannulation 15 coaxial to the central axis 4. Figures 2 and 3 show the intramedullary nail 1 according to the invention implanted in a tibia bone with a distal fracture. In Fig. 2 the intramedullary nail 1 is shown in the antero-posterior view with several locking screws at three distinct levels. The fracture line is below the isthmus locking level. The same situation is represented in Fig. 3 in a sagittal view. Arrows 19 and 20 in Figs. 2 and 3 indicate the range of freedom for the distal bone fragment of the treated bone which is similar to the degree of freedom of a conventional intramedullary nail (Fig. 4 and 5) whereas the proximal fragment has a reduced freedom compared to a conventional nail due to its isthmus locking section. If the fracture line is above the isthmus section the distal fragment has a reduced degree of freedom. Figures 4 and 5 show a conventional intramedullary nail with no isthmus locking section. Figure 4 represents an antero-posterior view and figure 5 a sagittal view. Arrows 17 and 18 in Figs. 4 and 5 indicate the range of freedom for the proximal bone fragment of the treated bone without an isthmus locking section which is much larger compared to the intramedullary nail 1 according to the invention represented in figures 2 and 3. Amendments of the claims under PCT Article 19 of the PCT/CH04/000094 Claims 1. Intramedullary nail (1) with a distal end (2) for insertion into the medullary canal, a proximal end (3), a central axis (4) and a generally rod-like shape over the hole length L, characterized in that A) said nail (1) has three distinct locking sections (5,6,7) with at least one through-hole (8) each for receiving locking screws whereby said three locking sections (5,6,7) are separated from each other by two distinct intermediate sections (9,10) having less through-holes (8) per length unit than each of said locking sections (5,6,7); and B) said proximal locking section (5) having the length LS and said first intermediate section (9) having the length L9 are arranged at an angle 13 in the range of 7° 13°. 2. Intramedullary nail (1) according to claim 1, characterized in that said distinct intermediate sections (9,10) have no through-holes (8) 3. Intramedullary nail (1) according to claim 1 or 2, characterized by A) a proximal locking section (5) extending from said proximal end (3) over the distance 0,22 L B) a distal locking section (6) extending from said distal end (2) over the distance 0,18 L and C) an isthmus locking section (7) located between said distal and proximal locking sections (5,6) with a proximal boundary (13) and a distal boundary (14) and a length of 0,08 L 4. Intramedullary nail (1) according to claim 3, characterized in that said proximal boundary (13) of said isthmus locking section (7) has a distance 0,27 L said distal boundary (11) of said proximal locking section (5). 5. Intramedullary nail (1) according to claim 3 or 4, characterized in that said distal boundary (14) of said isthmus locking section (7) has a distance 0,13 L 6. Intramedullary nail (1) according to one of the claims 3 to 5, characterized in that 0,32 L 7. Intramedullary nail (1) according to one of the claims 1 to 6, characterized in that it has a first intermediate section (9) having the length Lg between said proximal locking section (5) and said isthmus locking section (7) and preferably having no through holes (8). 8. Intramedullary nail (1) according to one of the claims 1 to 7, characterized in that said it has a second intermediate section (10) between said distal locking section (6) and said isthmus locking section (7) having the length L10 and preferably having no through holes (8). 9. Intramedullary nail (1) according to one of the claims 1 to 8, characterized in that said isthmus locking section (7) has two through holes (8), preferably arranged at a relative angle a in the range of 60° 10. Intramedullary nail (1) according to one of the claims 1 to 9, characterized in that the through hole (8) which is located nearest to said distal end (2) has a distance LD to said distal end (2) in the range of 0,01 L 11. Intramedullary nail (1) according to one of the claims 1 to 10, characterized in that the through hole (8) which is located nearest to said proximal end (3) has a distance Lp to said proximal end (3) in the range of 0,01 L

Full Text

Intramedullary nail
The invention relates to an intramedullary nail, in particular for the tibia, according to the preamble of claim 1.
Intramedullary nails with proximal and distal locking options are already known in the art. Depending on the fracture site and the anatomical situation, in particular for the tibia bone, an additional locking option on an intermediate level would be desirable. On this point, the invention intends to provide remedial measures. The invention is based on the objective of providing an intramedullary nail having an additional locking option, in the case of a tibial nail in the area of the Isthmus.
The invention solves the posed problem with an intramedullary nail that displays the features of claim 1.
The three level locking according to the invention optimizes the transmission of load by different distribution and transformation of the load applied to the nail. The additional intermediate locking level (between the proximal and distal level) serves as a support or artificial additional joint and therefore will divide the load on a new lever-arm-ratio. The intermediate level locking option may also serve in mechanical principle as an (elongated) Isthmus and will be the more efficient the bigger the gap between the nail diameter and the intramedullary canal of the bone is.
The various partial length of the intramedullary nail according to the invention are
defined as follows:
L5: proximal locking section extending from said proximal end to a distal boundary;
L6: distal locking section extending from said distal end to a proximal boundary;
L7 : isthmus locking section located between said distal and proximal locking sections
with a proximal boundary and a distal boundary;
L9 : distance between the proximal boundary of said isthmus locking section to said
distal boundary of said proximal locking section.
L-1o : distance of said distal boundary of said isthmus locking section to said proximal
boundary of said distal locking section; and

LD :distance between the distal end of the intramedullary nail to the through hole which is located nearest to said distal end.
LP : distance between the proximal end of the intramedullary nail to the through hole which is located nearest to said proximal end.
In a special embodiment the distinct intermediate sections of the intramedullary nail have no through-holes. This feature increases the stability in the fractured area.
In a further embodiment the intramedullary nail exhibits the following features:
A) a proximal locking section extending from said proximal end over the distance
0,22 L B) a distal locking section extending from said distal end over the distance
0,18 L a proximal boundary; and
C) an isthmus locking section located between said distal and proximal locking sections
with a proximal boundary and a distal boundary and a length of 0,08 L The advantage obtained by these features is the creation of enough space to place
sufficient locking options in different directions.
In a further embodiment the proximal boundary of said isthmus locking section has a distance 0,27 L In a further embodiment said distal boundary of said isthmus locking section has a distance of 0,13 L In a further embodiment the geometry of the intramedullary nail obeys to the condition: 0,32 L
In a further embodiment the intramedullary nail has a first intermediate section having the length L9 between said proximal locking section and said isthmus locking section and which preferably has no through holes. This feature increases the strength of the intramedullary nail.
In a further embodiment the intramedullary nail has a second intermediate section between said distal locking section and said isthmus locking section having the length L-io and which preferably has no through holes. This measure further increases the strength of the intramedullary nail.
In a further embodiment the isthmus locking section has two through holes, preferably arranged at a relative angle a in the range of 60° In a further embodiment the through hole which is located nearest to said distal end of said intramedullary nail has a distance LD to said distal end in the range of 0,01 L In another embodiment the through hole which is located nearest to said proximal end has a distance LP to said proximal end in the range of 0,01 L In a further embodiment said proximal locking section having the length Lsand said first intermediate section having the length Lg are arranged at an angle ft in the range of 7° The invention and additional configurations of the invention are explained in even more detail with reference to the partially schematic illustration of several embodiments.
The invention is described below on the basis of advantageous embodiments and with reference to the attached drawings in which:

Fig. 1 shows, in a longitudinal view, an intramedullary nail according to the invention;
Fig. 2 shows an antero-posterior (or frontal) view of a modified intramedullary nail according to the invention inserted in a schematically represented tibia bone;
Fig. 3 shows the intramedullary nail of Fig. 2 in a latero-medial (or sagittal) view;
Fig. 4 shows an antero-posterior (or frontal) view of an intramedullary nail according to prior art with only two level locking;
Fig. 5 shows the intramedullary nail according to prior art of Fig. 4 in a latero-medial view; and
Fig. 6 shows an orthogonal section of the nail according to Fig. 1 along the line VI - VI in the region of one of the locking holes.
The intramedullary nail 1 shown in Fig. 1 has a distal end 2 for insertion into the medullary canal, a proximal end 3, a central axis 4 and a generally rod-like shape over the hole length L. The intramedullary nail 1 has three distinct locking sections 5,6,7. Each of these locking sections 5,6,7 has a number of through-holes 8 for receiving locking screws. Proximal locking section 5 has two through holes 8, one of which is an elongated one. Distal locking section 6 has three trough holes 8 two of which are parallel and the intermediate third through hole is running vertical to the other two. As shown in Fig. 6 the isthmus locking section 7 has two through holes 8 which are disposed at an angle a of 90°.
Said three locking sections 5,6,7 are separated from each other by two distinct intermediate sections 9,10 having no through-holes 8.
The proximal locking section 5 extends from said proximal end 3 of said intramedullary nail 1 over a distance L5 equal to 0,25 L in direction of said distal end 2 to a distal boundary 11. The distal locking section 6 extends from said distal end 2 over the distance Le equal to 0,2 L in direction of said proximal end 3 to a proximal boundary 12 and the isthmus locking section 7 located between said distal and proximal locking sections 5,6 with a proximal boundary 13 and a distal boundary 14 has a length of L7

equal to 0,115 L. Said proximal boundary 13 of said isthmus locking section 7 has a
distance L9 equal to 0,3 L to said distal boundary 11 of said proximal locking section
5. Said distal boundary 14 of said isthmus locking section 7 has a distance LIO equal to
0,215 L to said proximal boundary 12 of said distal locking section 6. Therefore the sum
of the two distances LIO+ L6 is equal to 0,415 L.
The intramedullary nail 1 further has a first intermediate section 9 having the length L9
between said proximal locking section 5 and said isthmus locking section 7 and which
has no through holes 8. It further has a second intermediate section 10 between said
distal locking section 6 and said isthmus locking section 7 having the length LIO and
which has no through holes 8.
The through hole 8 which is located nearest to said distal end 2 has a distance LD to
said distal end 2 which is equal at least the diameter "d" of said through hole 8.
Said proximal locking section 5 having the length L5 and said first intermediate section
9 having the length Lg are arranged at an angle /? equal to 10° being the angle between
the prolongation 4d of the central axis 4 in the distal locking section 6 and the central
axis 4 in the proximal locking section 5.
As shown in Fig. 6 the intramedullary nail 1 has a cannulation 15 coaxial to the central
axis 4.
Figures 2 and 3 show the intramedullary nail 1 according to the invention implanted in a tibia bone with a distal fracture. In Fig. 2 the intramedullary nail 1 is shown in the antero-posterior view with several locking screws at three distinct levels. The fracture line is below the isthmus locking level. The same situation is represented in Fig. 3 in a sagittal view. Arrows 19 and 20 in Figs. 2 and 3 indicate the range of freedom for the distal bone fragment of the treated bone which is similar to the degree of freedom of a conventional intramedullary nail (Fig. 4 and 5) whereas the proximal fragment has a reduced freedom compared to a conventional nail due to its isthmus locking section. If the fracture line is above the isthmus section the distal fragment has a reduced degree of freedom.
Figures 4 and 5 show a conventional intramedullary nail with no isthmus locking section. Figure 4 represents an antero-posterior view and figure 5 a sagittal view. Arrows 17 and 18 in Figs. 4 and 5 indicate the range of freedom for the proximal bone fragment of the

treated bone without an isthmus locking section which is much larger compared to the intramedullary nail 1 according to the invention represented in figures 2 and 3.

Amendments of the claims under PCT Article 19 of the PCT/CH04/000094 Claims
1. Intramedullary nail (1) with a distal end (2) for insertion into the medullary canal, a
proximal end (3), a central axis (4) and a generally rod-like shape over the hole length
L,
characterized in that
A) said nail (1) has three distinct locking sections (5,6,7) with at least one through-hole
(8) each for receiving locking screws whereby said three locking sections (5,6,7) are
separated from each other by two distinct intermediate sections (9,10) having less
through-holes (8) per length unit than each of said locking sections (5,6,7); and
B) said proximal locking section (5) having the length LS and said first intermediate
section (9) having the length L9 are arranged at an angle 13 in the range of 7° 13°.
2. Intramedullary nail (1) according to claim 1, characterized in that said distinct
intermediate sections (9,10) have no through-holes (8)
3. Intramedullary nail (1) according to claim 1 or 2, characterized by
A) a proximal locking section (5) extending from said proximal end (3) over the distance
0,22 L B) a distal locking section (6) extending from said distal end (2) over the distance 0,18 L
and
C) an isthmus locking section (7) located between said distal and proximal locking
sections (5,6) with a proximal boundary (13) and a distal boundary (14) and a length of
0,08 L
4. Intramedullary nail (1) according to claim 3, characterized in that said proximal
boundary (13) of said isthmus locking section (7) has a distance 0,27 L said distal boundary (11) of said proximal locking section (5).
5. Intramedullary nail (1) according to claim 3 or 4, characterized in that said distal

boundary (14) of said isthmus locking section (7) has a distance 0,13 L 6. Intramedullary nail (1) according to one of the claims 3 to 5, characterized in that 0,32
L 7. Intramedullary nail (1) according to one of the claims 1 to 6, characterized in that it
has a first intermediate section (9) having the length Lg between said proximal locking
section (5) and said isthmus locking section (7) and preferably having no through holes
(8).
8. Intramedullary nail (1) according to one of the claims 1 to 7, characterized in that said
it has a second intermediate section (10) between said distal locking section (6) and
said isthmus locking section (7) having the length L10 and preferably having no through
holes (8).
9. Intramedullary nail (1) according to one of the claims 1 to 8, characterized in that said
isthmus locking section (7) has two through holes (8), preferably arranged at a relative
angle a in the range of 60°
10. Intramedullary nail (1) according to one of the claims 1 to 9, characterized in that the
through hole (8) which is located nearest to said distal end (2) has a distance LD to
said distal end (2) in the range of 0,01 L 11. Intramedullary nail (1) according to one of the claims 1 to 10, characterized in that
the through hole (8) which is located nearest to said proximal end (3) has a distance Lp
to said proximal end (3) in the range of 0,01 L

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Patent Number

269760

Indian Patent Application Number

3656/DELNP/2006

PG Journal Number

45/2015

Publication Date

06-Nov-2015

Grant Date

05-Nov-2015

Date of Filing

26-Jun-2006

Name of Patentee

SYNTHES GmbH

Applicant Address

of Eimattstrasse 3 CH-4436, Oberdorf, SWITZERLAND

Inventors:

#	Inventor's Name	Inventor's Address
1	ANDRE SCHLIENGER	AUSTRASSE 21, CH 4144 ARLESHEIM, 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 17/17

PCT International Application Number

PCT/CH2004/000094

PCT International Filing date

2004-02-23

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA