Intramedullary fixation device for metaphyseal long bone fractures and methods of using the same

• US 6,706,046 B2
• Filed: 12/10/2002
• Issued: 03/16/2004
• Est. Priority Date: 02/01/2000
• Status: Expired due to Term

• Current Assignee: Biomet Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Hand Innovations LLC (Johnson & Johnson)
• Inventors: Castañeda, Javier, Orbay, Jorge L.
• Primary Examiner(s): Shaver, Kevin
• Assistant Examiner(s): Priddy, Michael B.
• Application Number:
  US10/315,787
• Publication Number:
  US 20030083661A1
• Time in Patent Office: 462 Days
• Field of Search: 606/60, 606/62, 606/64, 606/67, 606/69-71, 606/72, 606/73, 606/86
• US Class Current: 606/62
• CPC Class Codes: A61B 17/1725 for applying transverse screws or pins through intramedullary nails or pins
• CPC Class Codes: A61B 17/1728 for holes for bone plates or plate screws
• CPC Class Codes: A61B 17/1782 for the hand or wrist
• CPC Class Codes: A61B 17/7233 with special means of locking the nail to the bone
• CPC Class Codes: A61B 17/8057 the interlocking form comprising a thread
• CPC Class Codes: A61B 17/8061 specially adapted for particular bones A61B17/70 and A61B17/74 take precedence
• CPC Class Codes: A61B 17/863 with thread interrupted or changing its form along shank, other than constant taper

Abstract

A fixation system includes a device having a nail portion and a plate portion, preferably horizontally and vertically offset relative to the nail portion by a neck portion. The nail portion includes threaded screw holes, and the plate portion includes longitudinally displaced peg holes, each of which is adapted to orient a peg in a different orientation from the others. The system also includes unicortical screws having a reasonably large head adapted to seat against the outer surface of the bone and a threaded shaft adapted to engage in the screw holes, and pegs adapted to engage in the peg holes. Bone is clamped between the nail portion and the head of the unicortical screws. The pegs provide stabilization and support for subchondral fragments. Moreover, as the pegs preferably enter the subchondral fragments from a plurality of directions, additional fixation of the device into the bone is provided.

Claims

1. A bone fracture fixation device, comprising:

a) an elongate nail portion including at least one threaded screw hole extending therein; and

b) a plate portion including at least one threaded peg hole extending completely through the plate portion, said plate portion being parallel to but not coaxial with said nail portion.

2. A bone fracture fixation device according to claim 1, wherein:

said nail portion includes at least two longitudinally displaced threaded screw holes which extend completely through the nail portion.

3. A bone fracture fixation device according to claim 1, wherein:

said nail portion includes a relatively rigid portion and a relatively resilient portion, and said at least one screw hole is in said relatively rigid portion.

4. A bone fracture fixation device according to claim 1, wherein:

said nail portion is straight.

5. A bone fracture fixation device according to claim 1, wherein:

said nail portion is tapered.

6. A bone fracture fixation device according to claim 1, wherein:

said nail portion has a circular cross-sectional shape.

7. A bone fracture fixation device according to claim 1, wherein:

said plate portion includes a plurality of threaded peg holes.

8. A bone fracture fixation device according to claim 7, wherein:

said plurality of threaded peg holes are longitudinally displaced in said plate portion.

9. A bone fracture fixation device according to claim 7, wherein:

at least one of said plurality of threaded peg holes has an oblique axis relative to the others of said plurality of threaded peg holes.

10. A bone fracture fixation device according to claim 9, wherein:

each of said threaded peg holes has an oblique axis relative to the others.

11. A bone fracture fixation device according to claim 1, wherein:

said nail portion and said plate portion are longitudinally displaced relative to each other.

12. A bone fracture fixation device according to claim 1, wherein:

said at least one threaded screw hole has a first thread pitch, said at least one threaded peg hole has a second thread pitch, and said first and second thread pitches are different.

13. A bone fracture fixation kit, comprising:

a) a fixation device having an elongate intramedullary portion and a plate portion, said intramedullary portion including at least one threaded screw hole and said plate portion including at least one threaded peg hole;

b) at least one machine screw having a shaft adapted to be threadably received in one of said at least one screw hole and having a head with a flat undersurface, said head being larger than said screw hole; and

c) at least one peg having a threaded head and a shaft, said head adapted to be threadably engaged in one of said at least one threaded peg hole.

14. A kit according to claim 13, wherein:

said at least one machine screw has a relatively blunt tip.

15. A kit according to claim 13, wherein:

said at least one peg has a non-threaded shaft.

16. A kit according to claim 13, wherein:

said plate portion includes a plurality of threaded peg holes each having an oblique axis relative to axes of the other peg holes.

17. A kit according to claim 13, wherein:

said at least one machine screw includes screws of different lengths.

18. A bone fracture fixation system, comprising:

a) a fixation device having an elongate intramedullary portion and a plate portion, said intramedullary portion including at least one threaded screw hole and said plate portion including at least one threaded peg hole;

b) at least one machine screw having a shaft threadably engaged in said at least one screw hole and having a head with a flat undersurface, said head being larger than said screw hole; and

c) at least one peg having a threaded head and a shaft, said head threadably engaged in said at least one threaded peg hole.

19. A fracture fixation system according to claim 18, wherein:

said plate portion includes a plurality of threaded peg holes each having an axis oblique relative to axes of the other peg holes, and

said at least one peg includes a plurality of pegs, said shaft of each of said pegs extending coaxial with one of said axes of said peg holes.

20. A bone fracture fixation kit, comprising:

a) a metal fixation device having an elongate intramedullary portion including a threaded screw hole; and

b) a machine screw having a head and a shaft,

said head having a flat undersurface which is larger than said threaded screw hole, and

said shaft including a tip portion, a body portion, and a clearance portion between said body portion and said head, said body portion having threads adapted to be threadably engaged in said threaded screw hole and defining a first diameter across said threads, said clearance portion having a relatively smooth surface compared with said body portion and a second diameter smaller than said first diameter, and said tip portion having a relatively smooth surface compared with said body portion and a third diameter smaller than said second diameter.

21. A kit according to claim 20, wherein:

said tip portion includes a shallow thread channel continuous with and of the same pitch as said threads of said body portion.

22. A kit according to claim 20, wherein:

said clearance portion includes a shallow thread channel continuous with and of the same pitch as said threads of said body portion.

23. A bone fracture fixation system for fixation of a metaphyseal fracture of a long bone which defines subchondral bone fragments, the long bone having interior and exterior surfaces and a cortex with and an intramedullary region therethrough, said device comprising:

a) a rigid elongate structure adapted to extend within the intramedullary region of the bone;

b) a rigid plate structure adapted for placement on the exterior surface of the bone over the subchondral bone fragments, said plate structure being coupled to said elongate structure;

c) means for clamping said elongate structure against the interior surface of the bone; and

d) a framework of shaft-like elements coupled to said plate structure and extending in oblique axes relative to each other so as to provide support for subchondral bone fragments.

24. A bone fracture fixation system according to claim 23, wherein:

said shaft-like elements comprise pegs.

25. A method of stabilizing a metaphyseal bone fracture, the bone having interior and exterior surfaces and a cortex with and an intramedullary region and the fracture region defining subchondral fragments, comprising:

a) providing a fixation device having an intramedullary portion and an external portion, the intramedullary portion having at least one threaded hole screw hole and the external portion having a plurality of threaded peg holes;

b) inserting the intramedullary portion into the bone at a location adjacent the bone fracture;

c) manipulating the device to provide the intramedullary portion within the intramedullary region of the bone;

d) first drilling at least one hole through the cortex in alignment with the at least one screw hole;

e) second drilling a plurality of holes into at least one subchondral fragment in alignment with the peg holes, at least one of the drilled holes being oblique relative to the others;

f) first inserting at least one screw through the cortex and into the screw hole, the screw having a relatively large head with a substantially flat undersurface;

g) tightening the at least one screw to cause the cortex of the bone to be clamped between the intramedullary portion of the device and the undersurface of the head of the at least one screw;

h) reducing the fracture; and

i) second inserting a plurality of pegs through the plurality of holes drilled in said second drilling to provide support for subchondral fragments and threadably engaging the head of the at least one peg in the at least one peg hole.

26. A method according to claim 25, wherein:

said first inserting includes inserting a screw having a length adapted to extend through a near cortex of the bone and into the intramedullary portion of the device, but not into a far cortex of the bone.

27. A method according to claim 25, wherein:

said first inserting includes inserting first and second screws, said first screw having a first length, said second screw having a second length, and said first and second lengths being different from each other.

28. A method according to claim 25, wherein:

said second inserting occurs after said reducing the fracture.

29. A method according to claim 25, wherein:

said first inserting includes inserting at least one machine screw through the cortex and into the screw hole.