Orthopedic rod with locking aperture

• US 20070123878A1
• Filed: 10/23/2006
• Published: 05/31/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Acumed Llc (Berkshire Hathaway Incorporated)
• Original Assignee: Acumed Llc (Berkshire Hathaway Incorporated)
• Inventors: Huebner, Randall, Shaver, Joseph, Morse, Bryon, Horst, Steven
• Granted Patent: US 7,914,532 B2
• Time in Patent Office: Days
• US Class Current: 606/64
• CPC Class Codes: A61B 17/72 Intramedullary pins, nails or other devices A61B17/744 takes precedence
• CPC Class Codes: A61B 17/7233 with special means of locking the nail to the bone
• CPC Class Codes: A61B 17/744 the longitudinal elements coupled to an intramedullary nail

Abstract

System, including methods and apparatus, for treating orthopedic conditions using a rod member structured for placement in a medullary canal of a bone and including at least one locking aperture with an internal thread structure. In some embodiments, the internal thread structure may include two or more thread leads disposed adjacent the same end of the locking aperture, two or more interspersed internal threads, and/or a thread depth substantially less than that of a corresponding threaded fastener for the locking aperture.

Claims

1. A device for treatment of an orthopedic condition, comprising:

a rod member for placement in a medullary canal of a bone, the rod member defining one or more apertures for receiving fasteners that connect the rod member to the bone, at least one of the apertures being a locking aperture having opposing ends and internal thread structure defining two or more thread leads disposed adjacent the same opposing end of the locking aperture, each thread lead being configured to threadably receive an external thread of a fastener.

2. The device of claim 1, wherein the rod member is an intramedullary rod for fixation of bone.

3. The device of claim 1, wherein the rod member is a stem of a prosthetic implant for replacement of an end of a bone.

4. The device of claim 1, wherein the internal thread structure includes two or more internal threads each extending to a distinct thread lead disposed adjacent the same opposing end of the locking aperture, and wherein the two or more internal threads have about the same pitch.

5. The device of claim 4, wherein the locking aperture defines a central axis, wherein the two or more internal threads are a number of threads, and wherein the two or more internal threads are offset from one another in a direction parallel to the central axis by a distance substantially equal to the pitch divided by the number.

6. The device of claim 4, wherein the two or more internal threads do not intersect one another.

7. The device of claim 1, wherein the internal thread structure includes at least three internal threads each extending to a distinct thread lead disposed adjacent the same opposing end of the locking aperture.

8. The device of claim 1, wherein the rod member defines a passage extending generally lengthwise through the rod member.

9. The device of claim 1, wherein the rod member defines a long axis, and wherein the locking aperture extends in a direction that is orthogonal to the long axis.

10. The device of claim 1, wherein the rod member has a trailing portion of greater diameter and configured to be disposed in or near a head of the bone, and wherein the at least one aperture is two or more locking apertures disposed in the trailing portion of the rod member.

11. A system for treatment of an orthopedic condition, comprising:

a rod member for placement in a medullary canal of a bone, the rod member defining one or more apertures for receiving fasteners that connect the rod member to the bone, at least one of the apertures being a locking aperture including two or more distinct internal threads that are interspersed with one another along the locking aperture; and

a fastener including an external thread configured for alternative threaded engagement with each of the two or more distinct internal threads.

12. The system of claim 11, wherein the two or more internal threads define non-intersecting helical paths.

13. The system of claim 11, wherein the fastener includes a shank, and wherein the shank includes only one external thread for alternative threaded engagement with each of the two or more internal threads.

14. The system of claim 11, the external thread and each internal thread having a depth, wherein the depth of the external thread is substantially greater than the depth of each internal thread.

15. The system of claim 11, wherein the depth of the external thread is at least about twice the depth of each internal thread.

16. A system for bone fixation, comprising:

a rod member for placement in a medullary canal of a bone, the rod member defining one or more apertures for receiving fasteners that connect the rod member to the bone, at least one of the apertures being a locking aperture including an internal thread having a depth; and

a fastener including an external thread configured for threaded engagement with the internal thread of the locking aperture, the external thread having a depth that is substantially greater than the depth of the internal thread.

17. The system of claim 16, wherein the depth of the external thread is at least about twice the depth of the internal thread.

18. The system of claim 16, wherein the fastener includes a shank, and wherein the shank has only one external thread for threaded engagement with the internal thread of the locking aperture.

19. A method of bone fixation, comprising:

selecting a rod member defining one or more apertures, at least one of the apertures being a locking aperture including opposing ends and internal thread structure defining two or more thread leads disposed adjacent the same opposing end;

placing the rod member into a medullary canal of a bone; and

connecting the rod member to the bone, at least partially, by advancing a fastener from the bone into the locking aperture such that an external thread of a fastener threads into the internal thread structure via only one of the two or more thread leads.

20. The method of claim 19, wherein the step of placing includes a step of placing the rod member into a humerus or a tibia.

21. The method of claim 19, wherein the step of placing includes a step of placing the locking aperture in or near a head of the bone.

22. The method of claim 19, wherein the step of placing includes a step of placing the rod member such that a portion of the rod member is external to the medullary canal.

23. The method of claim 19, wherein the step of connecting includes a step of randomly selecting the only one thread lead by which the external thread enters the internal thread structure of the locking aperture.