Method of endosteal nailing

• US 20050065528A1
• 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 7,425,213 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. A method of implanting an intramedullary nail into a fractured bone, the fracture separating the bone into first and second bone portions, said method comprising:

a) inserting an implant into a medullary canal of a bone such that it extends intramedullary on two sides of a bone fracture; and

b) clamping the bone with sufficient force to immobolize the fracture by forcing the implant against an endosteal surface of the bone and applying a force against the outer surface of the bone.

2. A method according to claim 1, wherein:

said applying a force against the outer surface of the bone includes inserting machine screws from outside the bone into threaded holes in the implant on the two sides of the fracture, the machine screws having relatively large heads with an undersurface, and tightening the screws such that the undersurfaces apply a force against the outer surface of the bone.

3. A method according to claim 2, wherein:

said undersurface is substantially flat.

4. A method according to claim 3, wherein:

said machine screws have a shaft and an area is 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.

5. A method according to claim 4, 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)}.

6. A method according to claim 4, 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)}.

7. A method of implanting an intramedullary nail into a fractured bone, the fracture demarcating the bone into first and second bone portions, said method comprising:

a) introducing at least half the length of the nail into the medullary canal of the first portion of the bone, the nail having a plurality of threaded screw holes;

b) reducing the fractured bone, wherein once the fracture is reduced the entirety of the nail is within the medullary canal;

c) coupling a jig to a first location on the nail;

d) using the jig to drill holes through the bone in alignment with some of the threaded screw holes;

e) providing screws having a shaft with machine threads and a head;

f) introducing the shafts of the screws through the holes drilled in the bone and into the screw holes and rotating the screws to cause clamping of the bone between the heads of the screws and the nail;

g) decoupling the jig from the nail;

h) coupling the jig at a second location on the nail longitudinal displaced from the first location;

i) using the jig to drill holes through the bone in alignment with the remainder of the threaded screw holes;

j) decoupling the jig from the nail; and

k) introducing the shaft of the screws through the holes drilled in the bone and into the remainder of the screw holes.

8. A method according to claim 7, further comprising:

after said reducing the fracture, moving the implant within the medullary canal such that relatively equal lengths of the implant are located on each side of the fracture.

9. A method according to claim 7, further comprising:

prior to said introducing, coupling the jig to the nail, and manipulating the nail relative to the bone with the jig.

10. A method according to claim 9, further comprising:

prior to said reducing the fracture, coupling the jig to the nail, and manipulating the nail relative to the bone with the jig.

11. A method of implanting an intramedullary nail into a fractured bone, the fracture separating the bone into first and second bone portions, said method comprising:

a) introducing at least a portion of the nail into the medullary canal of the first portion of the bone, the nail having a plurality of threaded screw holes;

b) reducing the fractured bone;

c) coupling a jig at a longitudinally central location on the nail;

d) using the jig to drill holes through the bone in alignment with the threaded screw holes;

e) providing screws having a shaft with machine threads and a head;

f) introducing the shaft of the screws through the holes drilled in the bone and into the screw holes and rotating the screws to cause clamping of the bone between the heads of the screws and the nail; and

g) decoupling the jig from the nail.

12. A method according to claim 11, further comprising:

after said reducing the fracture, moving the implant within the medullary canal such that relatively equal lengths of the implant are located on each side of the fracture.

13. A method according to claim 11, further comprising:

prior to said introducing, coupling the jig to the nail, and manipulating the nail relative to the bone with the jig.

14. A method according to claim 11, further comprising:

prior to said reducing the fracture, coupling the jig to the nail, and manipulating the nail relative to the bone with the jig.

15. A method of implanting an intramedullary nail into a fractured bone, the fracture demarcating the bone into first and second bone portions, said method comprising:

a) introducing the nail into the medullary canal of the bone, the nail having a plurality of threaded screw holes located under the first and second bone portions;

b) coupling a jig to a first location on the nail;

c) using the jig to drill holes through the first bone portion in alignment with at least one of the threaded screw holes;

d) providing screws having a shaft with machine threads and a head;

e) introducing the shafts of the screws through the holes drilled in the bone and into the screw holes and rotating the screws to cause clamping of the bone between the heads of the screws and the nail;

f) decoupling the jig from the nail;

g) coupling a jig at a second location on the nail longitudinal displaced from the first location;

h) reducing the fractured bone, wherein once the fracture is reduced substantially the entirety of the nail is within the medullary canal;

i) using the jig to drill holes through the second bone portion in alignment with threaded screw holes thereunder; and

j) introducing the shaft of the screws through the holes drilled in the second bone portion and into the screw holes thereunder.

16. A method according to claim 15, wherein:

the same jig is used for steps b) and g).

17. A method according to claim 15, wherein:

said coupling a jig to a first location on the nail includes coupling a jig to a longitudinal center of the nail.

18. A method according to claim 15, wherein:

said coupling a jig to a first location on the nail includes coupling a jig between the first and second bone locations.

19. A method according to claim 15, wherein:

said using the jig to drill holes through the second bone portion is performed while the reduced fracture is held in compression.