Endosteal nail

• US 20050065520A1
• Filed: 11/10/2004
• Published: 03/24/2005
• Est. Priority Date: 12/10/2002
• Status: Active Grant

• Current Assignee: Biomet Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Depuy Products Incorporated (Johnson & Johnson)
• Inventors: Orbay, Jorge L.
• Granted Patent: US 7,780,664 B2
• Time in Patent Office: Days
• 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 17/72 Intramedullary pins, nails or other devices A61B17/744 takes precedence
• CPC Class Codes: A61B 17/7225 for bone compression
• CPC Class Codes: A61B 17/7233 with special means of locking the nail to the bone
• CPC Class Codes: A61B 17/725 with locking pins or screws of special form
• CPC Class Codes: A61B 17/7291 for small bones, e.g. in the foot, ankle, hand or wrist
• CPC Class Codes: A61B 17/8052 immobilised relative to screws by interlocking form of the heads and plate holes, e.g. conical or threaded

Abstract

The system includes an elongate intramedullary nail which is rigidly fixed under compression to the endosteal surface of a bone with unicortical locking machine screws inserted through the bone and into a plurality of longitudinally displaced threaded holes in the nail. A jig is provided for drilling holes through the bone in alignment with the screw holes in the nail. The nail and jig each include anti-rotation structure at which the nail and jig can be coupled together in a fixed alignment. A method is also provided for implanting an intramedullary nail on two sides of a bone fracture, and clamping the bone with sufficient force to immobolize the fracture by forcing the implant against an endosteal surface of the bone and applying a compressive force against the outer surface of the bone.

Claims

1. An intramedullary nail system for use with a jig, comprising:

an elongate nail including at least four threaded parallel screw holes, said screw holes oriented normal to an endosteal surface of said nail, and a non-circular recess in an endosteal surface of said nail for mating with a portion of the jig to lock the jig in a rotational orientation relative to said nail.

2. A nail system according to claim 1, wherein:

said non-circular recess is provided at one of said screw holes.

3. A nail system according to claim 1, wherein:

said non-circular recess is centrally located along a length of said nail.

4. A nail system according to claim 1, wherein:

said non-circular recess is square or rectangular.

5. A nail system according to claim 1, wherein:

said nail defines two elongate portions, one on each side of said non-circular recess, and an equal number of said threaded screw holes are provided along each said portion.

6. A nail system according to claim 1, wherein:

said nail includes first and second ends which are tapered.

7. A nail system according to claim 1, further comprising:

a plurality of unicortical machine screws each having a head and a shaft configured to threadably engage in one of said screw holes,

wherein when said screws are inserted through bone and into said screw holes the bone is clamped between said head of said screws.

8. An orthopedic nail system, comprising:

a) an elongate nail including a plurality of threaded screw holes, said screw holes oriented normal to an endosteal surface of said nail, and a non-circular recess in an endosteal surface of said nail;

b) a plurality of unicortical machine screws each having a head and a shaft configured to threadably engage in one of said screw holes; and

c) a removable jig having a first portion which extends through the bone and engages within said non-circular recess to lock said jig and said nail in alignment and a second portion sized to extend over the screw holes of the nail and receive a drill guide to guide a drill to drill holes into bone into alignment with the screw holes therebelow,

wherein when said screws are inserted through bone and into said screw holes the bone is clamped between said head of said screws and said nail.

9. An orthopedic nail system according to claim 8, wherein:

said nail includes a plurality of non-circular recesses, and said first portion of said jig may be removably engaged in any of said recesses.

10. An orthopedic nail system according to claim 8, wherein:

said non-circular recess is provided at one of said screw holes.

11. An orthopedic nail system according to claim 8, wherein:

said non-circular recess is centrally located along a length of said nail.

12. An orthopedic nail fixation system according to claim 8, wherein:

said non-circular recess is square or rectangular.

13. An orthopedic nail system according to claim 8, wherein:

said nail defines two elongate portions, one on each side of said non-circular recess, and an equal number of said threaded screw holes are provided along each said portion.

14. An orthopedic nail system according to claim 8, wherein:

said nail includes first and second ends which are tapered.

15. An orthopedic nail system according to claim 8, wherein:

said head of said screw includes a flat undersurface.

16. An orthopedic nail system according to claim 8, wherein:

said second portion includes first and second co-linear parts extending on either side of said first portion, wherein said second part is longer than said first part.

17. An orthopedic nail system, comprising:

a) an elongate nail including a plurality of threaded screw holes, said screw holes oriented normal to an endosteal surface of said nail, and a plurality of non-circular recesses in an endosteal surface of said nail;

b) a plurality of unicortical machine screws each having a head and a shaft configured to threadably engage in one of said screw holes; and

c) a removable jig having a first portion which extends through the bone and engages within said non-circular recess to lock said jig and said nail in alignment and a second portion sized to extend over at least a portion of said screw holes of the nail, said second portion provided with means to guide a drill to drill holes into bone into alignment with the screw holes therebelow,

wherein when said screws are inserted through bone and into said screw holes the bone is clamped between said head of said screws and said nail.

18. An orthopedic nail system, comprising:

a) an elongate nail including a plurality of threaded screw holes, a plurality of such screw holes on first and second sides of a longitudinal center of said nail, said screw holes oriented normal to an endosteal surface of said nail, and a plurality of non-circular recesses in an endosteal surface of said nail; and

b) a jig having a first portion which extends through the bone and removably engages within said non-circular recess to provide said jig and said nail in rotational alignment, and a second portion having

a first side which is of sufficient length to extend over said screw holes on said first side of said longitudinal center of said nail and which includes openings in alignment therewith for drilling holes in alignment therewith, and

a second side which is of sufficient length to extend over at least one of said screw holes on said second first side of said longitudinal center of said nail and which includes at least one openings in alignment therewith for drilling holes in alignment therewith.

19. An orthopedic nail system according to claim 18, further comprising

c) means for lock said jig relative to said nail.

20. An orthopedic system according to claim 18, wherein:

said second side is of sufficient length to extend over all of said screw holes on said second second side of said longitudinal center and includes openings for drilling holes in alignment with respective screw holes therebelow.

21. An orthopedic system according to claim 18, further comprising:

c) a plurality of unicortical machine screws each having a head and a shaft configured to threadably engage in one of said screw holes,

wherein when said screws are inserted through bone and into said screw holes the bone is clamped between said head of said screws and said nail.

22. An orthopedic nail system comprising:

a) an elongate nail including a plurality of threaded screw holes oriented normal to an endosteal surface of said nail, at least one of said screw holes adapted to be located on either side of a diaphyseal fracture; and

b) a plurality of unicortical machine screws each having a head and a shaft configured to threadably engage in one of said screw holes, said head having an undersurface for contacting bone, and an area being defined by a cross-section through said shaft, wherein the ratio of said surface area of said undersurface of said head to said area of said cross-section through said shaft is at least 1.5.

23. An orthopedic nail system according to claim 22, wherein:

the ratio of said surface area of said undersurface of said head to said area of cross-section through said shaft is approximately {square root}{square root over (3)}.

24. An orthopedic nail system according to claim 23, wherein:

the ratio of said surface area of said undersurface of said head to said area of cross-section through said shaft is at least approximately {square root}{square root over (3)}.

25. An orthopedic nail system according to claim 23, wherein:

said undersurface is substantially flat.