System for intramedullary rod fixation and method therefor

• US 20070100342A1
• Filed: 10/14/2005
• Published: 05/03/2007
• Est. Priority Date: 10/14/2005
• Status: Active Grant

• Current Assignee: Pega Medical, Inc. (Orthopediatrics Corporation)
• Original Assignee: Daniel Green, Joseph Molino
• Inventors: Green, Daniel, Molino, Joseph
• Granted Patent: US 7,785,326 B2
• Time in Patent Office: Days
• US Class Current: 606/64
• CPC Class Codes: A61B 17/1717 for applying intramedullary nails or pins
• CPC Class Codes: A61B 17/72 Intramedullary pins, nails or other devices A61B17/744 takes precedence
• CPC Class Codes: A61B 17/725 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 17/8605 Heads, i.e. proximal ends projecting from bone
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts

Abstract

A system and method for securing an intramedullary rod in a medullary canal of a long bone is provided. The system includes an intramedullary rod and a screw assembly for receiving the rod. The screw assembly has a transverse receiving bore for receiving the intramedullary rod and a securing member movable toward the bore for securing the rod to the screw assembly. An alignment jig may also be provided for aligning the rod with the receiving bore during installation.

Claims

1. A screw assembly for securing an intramedullary rod in a medullary canal of a bone, the screw assembly comprising:

a screw body having a shaft and at least one receiving bore extending transversely through the shaft, and being adapted to receive an intramedullary rod; and

a securing member movable toward the at least one receiving bore to thereby secure the rod to the screw assembly.

2. A screw assembly according to claim 1, wherein the screw body comprises an internal cavity extending along a longitudinal axis of the shaft and intersecting at least one receiving bore.

3. A screw assembly according to claim 2, wherein the securing member is positioned within the internal cavity.

4. A screw assembly according to claim 3, wherein the internal cavity and the securing member comprise mutually engageable connection such that rotation of the securing member in one direction causes linear movement of the securing member toward the receiving bore and rotation of the securing member in the opposite direction causes linear movement of the securing member away from the receiving bore.

5. A screw assembly according to claim 4, wherein said mutually engageable connection comprises mutually engageable threads, said assembly further comprising an auger portion located at one end of the shaft and a head portion located at an opposite end of the shaft.

6. A screw assembly according to claim 5, wherein the head portion comprises a depression that intersects with the internal cavity.

7. A screw assembly according to claim 6, wherein the depression is hexagonal in shape.

8. A screw assembly according to claim 5, and further comprising an indicator associated with the head portion for indicating orientation of the at least one receiving bore.

9. A screw assembly according to claim 8, wherein the indicator comprises at least one mark on the head portion in alignment with a longitudinal axis of the at least one receiving bore.

10. A screw assembly according to claim 5, wherein the auger portion comprises a conical section and a thread that spirals around the conical section.

11. A screw assembly according to claim 5, wherein the shaft comprises a second receiving bore located between the auger portion and the head portion, the second receiving bore being substantially parallel to a first receiving bore and being sized to receive an intramedullary rod.

12. A system for securing an intramedullary rod in a medullary canal of a bone, the system comprising:

an intramedullary rod;

a screw assembly having a at least one receiving bore extending transversely therethrough for receiving the intramedullary rod and a securing member movable toward the at least one receiving bore for securing the rod to the screw assembly.

13. A system according to claim 12, and further comprising an alignment jig operably associated with the screw assembly and intramedullary rod for aligning the rod with the at least one receiving bore within a medullary canal of a bone structure.

14. A system according to claim 13, wherein the alignment jig comprises a base member with a first leg and a second leg extending from the first leg, the second leg being adapted for engaging the screw assembly and the first leg being adapted to contact a bone structure and having an opening coincident with the at least one receiving bore to thereby align the intramedullary rod with the at least one receiving bore within a medullary canal of the bone structure.

15. A system according to claim 14, wherein the alignment jig further comprises a tubular guide member extending from the first leg and coincident with the opening, the tubular guide member being adapted to receive a drill bit for forming a hole in the bone structure in alignment with the at least one receiving bore and to receive the intramedullary rod for guiding the rod toward the at least one receiving bore.

16. A system according to claim 15, wherein the screw assembly comprises a head portion with a depression, and further wherein the alignment jig comprises a bar connected to the second leg, the bar being adapted to fit within the depression.

17. A system according to claim 16, wherein the bar is pivotally connected to the second leg.

18. A system according to claim 17, wherein the first and second legs are perpendicular.

19. A method for installing an intramedullary rod within a medullary canal of a bone, the method comprising the steps of:

providing a screw with at least one receiving bore being transverse to a longitudinal axis of the screw;

installing the screw into the bone such that the at least one receiving transverse bore is positioned within the medullary canal;

inserting an intramedullary rod into the medullary canal and through the at least one receiving transverse bore.

20. A method according to claim 19, and further comprising a step of securing the intramedullary rod to the screw.

21. A method according to claim 20, wherein the step of securing comprises securing the rod within the at least one receiving transverse bore.

22. A method according to claim 19, wherein the step of inserting the intramedullary rod through the at least one receiving transverse bore includes aligning the rod with the bore.

23. A method according to claim 22, wherein the step of aligning includes orienting the at least one receiving transverse bore in a longitudinal direction of the bone.

24. A method according to claim 23, wherein the step of aligning further comprises:

providing a jig with a first arm and a second arm, the second arm having an engagement member for engaging the screw, the first arm having an opening;

engaging the engagement member with the screw; and

contacting the bone with the first arm such that the opening is in alignment with the medullary canal and the at least one receiving transverse bore.

25. A method according to claim 24, wherein the step of inserting the intramedullary rod comprises:

forming a hole in the bone coincident with the opening and the at least one receiving transverse bore; and

inserting the rod through the opening, the hole and the at least one receiving transverse bore.

26. A method according to claim 25, and further comprising securing the intramedullary rod to the screw.

27. A method according to claim 26, wherein the step of securing comprises securing the rod within the at least one receiving transverse bore.