Hip fixation with load-controlled dynamization

Patent metadata

Field	Value
Publication number	US-9526542-B2
Application number	US-201514706922-A
Country	US
Kind code	B2
Filing date	May 7, 2015
Priority date	May 7, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

System, including methods and apparatus, for hip fixation with load-controlled dynamization. In exemplary embodiments, the system may comprise a fixation element, such as a screw, configured to be placed into a proximal femur of a subject, with a leading end of the fixation element anchored in a head of the proximal femur. The system also may comprise a stop member configured to be connected (e.g., via a nail or plate) to the proximal femur. The system further may comprise a deformable member configured to be irreversibly deformed by compressive force exerted on at least a portion of the deformable member by the fixation element and the stop member in response to a load applied to the proximal femur by the subject, such that the fixation element and the stop member move relative to one another parallel to a long axis of the fixation element.

First claim

I claim:

1. A system for hip fixation, comprising:
a fixation element configured to be placed into a proximal femur of a subject such that a leading end of the fixation element is anchored in a head of the proximal femur and the fixation element extends from a lateral portion of the proximal femur to the head of the proximal femur;
a stop member configured to be connected to the lateral portion of the proximal femur; and
a deformable member configured to be operatively disposed between the fixation element and the stop member and irreversibly deformed in response to a load applied to the proximal femur by the subject that urges the leading end of the fixation element and the stop member toward one another;
wherein irreversible deformation of the deformable member in response to the load is accompanied by translational movement of the fixation element and the stop member relative to one another parallel to a long axis of the fixation element.

2. The system of claim 1 , wherein the fixation element has a shaft, and wherein the deformable member is attached to the shaft such that the fixation element and the deformable member are configured to be placed into the proximal femur as a unit.

3. The system of claim 2 , wherein the deformable member is attached to a side surface region of shaft.

4. The system of claim 3 , wherein the side surface region of the shaft defines a trough, and wherein the deformable member is located in the trough.

5. The system of claim 3 , wherein the side surface region forms a flat region of the shaft, and wherein the deformable member is attached to the flat region of the shaft.

6. The system of claim 1 , further comprising a nail defining a transverse opening, wherein the fixation element is configured to extend through the transverse opening, and wherein the stop member is attached or attachable to the nail and configured to engage the deformable member inside the nail.

7. The system of claim 1 , wherein the stop member is configured to restrict rotation of the fixation element about the long axis and is adjustably positionable inside the nail, along a longitudinal axis of the nail, by turning at least a portion of the stop member.

8. The system of claim 1 , further comprising a side plate including a mounting portion to attach the side plate to a lateral cortex of the proximal femur and also including a barrel portion configured to be placed into the femur, the barrel portion defining a channel to receive a trailing portion of the fixation element, wherein the deformable member is configured to be disposed in the channel between the stop member and the trailing portion of the fixation element.

9. The system of claim 8 , further comprising a compression screw configured to extend through the stop member and the deformable member and into threaded engagement with the fixation element.

10. The system of claim 1 , wherein the system comprises
a plurality of fixation elements each configured to be placed into a same proximal femur of a subject such that a leading end of each fixation element is anchored in a head of the proximal femur and the fixation element extends from a lateral portion of the proximal femur and to the head of the proximal femur;
a deformable member operatively associated with each fixation element; and
a buttress plate configured to be attached to the proximal femur and including a stop member for each fixation element.

11. A system for hip fixation, comprising:
a nail configured to be placed longitudinally into a proximal femur of a subject and defining a transverse opening;
a fixation element configured to be placed into the proximal femur such that a leading end of the fixation element is anchored in a head of the proximal femur and the fixation element extends from a lateral portion of the proximal femur, through the transverse opening of the nail, and to the head of the proximal femur, the fixation element including a shaft defining a long axis;
a deformable member attached to the shaft of the fixation element; and
a stop member attached or attachable to the nail and configured to engage the deformable member inside the nail and to restrict rotation of the fixation element about the long axis;
wherein the deformable member is configured to be irreversibly deformed by compressive force exerted on at least a portion of the deformable member by the fixation element and the stop member in response to a load applied to the proximal femur by the subject, such that the fixation element and the stop member move relative to one another parallel to the long axis of the shaft.

12. The system of claim 11 , wherein the deformable member is attached to a side surface region of shaft.

13. The system of claim 12 , wherein the side surface region is non-cylindrical.

14. The system of claim 13 , wherein the side surface region forms a trough, and wherein the deformable member is located in the trough.

15. The system of claim 11 , wherein the stop member is adjustably positionable longitudinally in the nail by turning at least a portion of the stop member.

16. A system for hip fixation, comprising:
a fixation element configured to be placed into a proximal femur such that a leading end of the fixation element is anchored in a head of the proximal femur and the fixation element extends from a lateral portion of the proximal femur to the head of the proximal femur, the fixation element defining a long axis;
a side plate including a mounting portion to attach the side plate to a lateral cortex of the femur and also including a barrel portion configured to extend into the proximal femur, the barrel portion defining a channel to receive a trailing portion of the fixation element;
a stop member attached or attachable to the barrel portion; and
a deformable member configured to be operatively disposed between the trailing portion of the fixation element and the stop member and to be irreversibly deformed in response to a load applied to the system by the subject that urges the leading end of the fixation element and the stop member toward one another, such that the fixation element and the barrel portion move relative to one another parallel to the long axis, and such that the fixation element and the stop member move translationally relative to one another parallel to the long axis.

17. The system of claim 16 , wherein the stop member is discrete with respect to the barrel portion.

18. The system of claim 17 , wherein the stop member is configured to be disposed in threaded engagement with the barrel portion.

19. The system of claim 16 , wherein the deformable member is not attached to the fixation element, and wherein the deformable member is not attached to the stop member.

20. The system of claim 16 , further comprising a compression screw configured to extend through an opening defined by the stop member and an opening defined by the deformable member and into threaded engagement with the shaft of the fixation element.

21. The system of claim 16 , wherein the stop member is attached to the deformable member.

Assignees

• Acumed Llc

Inventors

• Ehmke Larry W

Classifications

• A61B2017/681

  Alignment, compression, or distraction mechanisms · CPC title

• A61B17/8685

  comprising multiple separate parts · CPC title

• A61B17/725

  with locking pins or screws of special form · CPC title

• A61B17/746 Primary

  the longitudinal elements coupled to a plate opposite the femoral head · CPC title

• A61B17/683

  comprising bone transfixation elements, e.g. bolt with a distal cooperating element such as a nut · CPC title