Intramedullary nail
View Patent ↗An intramedullary nail includes an elongated body extending along a central longitudinal axis. The intramedullary nail includes a straight proximal end portion along with a straight distal end portion extending proximally from a distal end of the nail by a predetermined length and a central portion extending proximally from a proximal end of the distal end portion to a distal end of the proximal end portion. The central portion includes a first curved portion having a first length with a first radius of curvature and a second curved portion having a second length shorter than the first length and a second, non-zero radius of curvature smaller than the first radius of curvature.
1. An intramedullary nail comprising:
an elongated body extending along a central longitudinal axis and including:
a straight proximal end portion;
a straight distal end portion extending proximally from a distal end of the nail by a predetermined length; and
a central portion extending proximally from a proximal end of the distal end portion to a distal end of the proximal end portion, wherein the central portion includes a first curved portion having a first length with a first radius of curvature, and a second curved portion having a second length shorter than the first length and a second, non-zero radius of curvature smaller than the first radius of curvature.
2. The intramedullary nail of claim 1 , wherein the second curved portion is positioned proximally of the first curved portion.
3. The intramedullary nail of claim 1 , wherein the first and second curved portions lie in the anatomical medio-lateral plane in an operative configuration.
4. The intramedullary nail of claim 1 , wherein the proximal end portion axially adjoins the second curved portion and is straight.
5. The intramedullary nail of claim 1 , wherein the first curved portion has a radius of curvature ranging from about 300 to about 1300 mm.
6. The intramedullary nail of claim 1 , wherein the intramedullary nail has a total length ranging from 200 to 500 mm.
7. The intramedullary nail of claim 1 , wherein tangents at two end points of the central portion, including the first and second curved portions enclose an angle gamma between about 9° and about 12°.
8. The intramedullary nail of claim 7 , wherein tangents at two end points of the first curved portion enclose an angle alpha ranging from about 7° to about 10°.
9. The intramedullary nail of claim 8 , wherein the angle alpha ranges from about 8° to about 9°.
10. The intramedullary nail of claim 7 , wherein tangents at two end points of the second curved portion enclose an angle beta ranging from about 1° to about 3°.
11. The intramedullary nail of claim 1 , wherein a ratio of the total length of the intramedullary nail to the radius of the first curved portion ranges from about 0.2 to about 0.8.
12. The intramedullary nail of claim 1 , wherein a length of the proximal end portion ranges from ⅙ to ⅓ of the total length of the intramedullary nail.
13. The intramedullary nail of claim 1 , wherein a length of the distal end portion ranges between about 0.20 to about 0.55 of the total length of the intramedullary nail.
14. The intramedullary nail of claim 1 , wherein the first curved portion has a length ranging from about 0.2 to about 0.4 of the total length of the intramedullary nail.
15. The intramedullary nail of claim 1 , wherein the distal end portion has a length about 0.25 of the total length of the intramedullary nail.
16. The intramedullary nail of claim 1 , further comprising a longitudinal borehole extending through the body, a borehole axis of the borehole being coaxial with the central longitudinal axis.
17. The intramedullary nail of claim 1 , further comprising:
a first locking hole provided in the proximal end portion, a first locking hole axis of the first locking hole extending transversely to the central longitudinal axis; and
a second locking hole provided in the distal end portion, a second locking hole axis of the second locking hole extending transversely to the central longitudinal axis.
18. The intramedullary nail of claim 17 , further comprising a third locking hole provided in the distal end portion, a third locking hole axis of the third locking hole extending transversely to the central longitudinal axis, the second and third locking hole axes enclosing an angle of about 45° to about 90°.
19. The intramedullary nail of claim 18 , further comprising a fourth locking hole provided in the distal end portion, a fourth locking hole axis of the fourth locking hole extending transversely to the central longitudinal axis, wherein a distance between adjacent ones of the second, third and fourth locking holes are different from one another.
20. The intramedullary nail of claim 1 , wherein the second curved section has a radius ranging from about 10 to about 50 mm.