System and Method for Joint Restoration by Extracapsular Means

• US 20080294269A1
• Filed: 06/14/2006
• Published: 11/27/2008
• Est. Priority Date: 06/14/2005
• Status: Active Grant

• Current Assignee: Barry M. Fell
• Original Assignee: Barry M. Fell
• Inventors: Fell, Barry M.
• Granted Patent: US 7,867,235 B2
• Time in Patent Office: Days
• US Class Current: 623/23.48
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms
• CPC Class Codes: A61B 17/7216 for bone lengthening or compression A61B17/7258 takes precedence
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61F 2/30756 Cartilage endoprostheses A61F2/3603 takes precedence
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2002/286 Bone stimulation by mechanical vibrations for enhancing ossification
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol

Abstract

A system and method for joint restoration by extracapsular means includes an actuator operable to apply a force to a portion of a bone to effect a change 5 in the joint space geometry. One embodiment of the system includes an actuator operable to apply a cyclic loading to subchondral bone of a femur, wherein loads of a predetermined magnitude are alternately applied and released. Between periods of cyclic loading, rest periods are provided where no load is applied. Over time, the femoral joint surface is remodeled in accordance with the location, direction, magnitude, and frequency of the loading.

Claims

1. A method for effecting displacement of bone for restoration of a skeletal joint, the joint including a portion of the bone having an articular surface thereon and a mating member configured to cooperate with the articular surface of the bone, the articular surface being disposed at a first position relative to the mating member, the method comprising:

applying at least one loading condition to the bone at a position proximate the articular surface, thereby facilitating a structural change in the bone proximate the articular surface;

monitoring the bone for structural changes; and

removing application of the at least one loading condition when the bone has achieved a certain structural change, including a change in the position of the articular surface relative to the mating member.

2. The method of claim 1, further comprising:

creating an aperture in the bone proximate the articular surface, thereby making accessible an internal portion of the bone generally opposite the articular surface;

accessing the internal portion of the bone through the aperture in the bone; and

applying the at least one loading condition to the internal portion of the bone, thereby facilitating structural changes in the bone supporting the articular surface.

3. The method of claim 2, wherein the at least one loading condition is applied to the bone with a joint restoration system including a housing having an aperture therethrough, and an elongate member configured for insertion into the aperture in the housing, the method further comprising attaching the housing to the bone such that the aperture in the housing is generally aligned with the aperture in the bone, and

wherein applying the at least one loading condition to the internal portion of the bone includes inserting the elongate member through the apertures such that the elongate member contacts the internal portion of the bone and applies a force thereto.

4. The method of claim 3, the joint restoration system further including a compression member configured to cooperate with the housing to apply a force to the elongate member, the method further comprising inserting the compression member into the housing such that it contacts the elongate member and imparts a force thereto, thereby facilitating the application of the force to the internal portion of the bone by the elongate member.

5. The method of claim 4, further comprising adjusting after some period of time the compression member to change the force applied to the elongate member, the change in force effecting at least one of the application of a force different from an initial force or the application of a force generally the same as the initial force, necessitated by a change in the initial force resulting from structural changes in the bone.

6. The method of claim 1, wherein the at least one loading condition is applied to an external portion of the bone such that the certain structural change includes at least one of an increase in a length of the bone or a decrease in a length of the bone.

7. The method of claim 6, wherein the at least one loading condition is applied to the bone with a joint restoration system including an electromechanical actuator, the method further comprising:

attaching the actuator to the external portion of the bone; and

operating the actuator to apply the at least one loading condition to the external portion of the bone.

8. The method of claim 1, wherein applying at least one loading condition to the bone includes applying at least one of a static load or a cyclic load to the bone.

9. The method of claim 8, wherein applying the at least one loading condition includes:

applying a first static load to the bone, and

applying a second static load to the bone to effect at least one of the application of a load different from the first static load or the application of a load generally the same as the first static load, necessitated by a change in the first static load resulting from structural changes in the bone.

10. The method of claim 8, wherein applying the at least one loading condition includes applying at least one cyclic loading condition, each of the respective cyclic loading conditions being defined by at least a force amplitude and a frequency of force application.

11. The method of claim 8, wherein applying at least one loading condition to the bone includes applying at least one cyclic loading condition to facilitate bone deformation, and at least one static loading condition to increase bone density.

12. A method for effecting displacement of bone for restoration of a skeletal joint, the joint including a portion of the bone having an articular surface thereon and a mating member configured to cooperate with the articular surface of the bone, the articular surface being disposed at a first position relative to the mating member, the method comprising:

creating an aperture in the bone proximate the articular surface, such that the articular surface is not penetrated;

inserting an elongate member through the aperture such that the elongate member contacts an internal portion of the bone generally opposite the articular surface;

applying at least one loading condition to the internal portion of the bone through the elongate member;

monitoring the bone for structural changes; and

removing application of the at least one loading condition when the bone has achieved a certain structural change, including a change in the position of the articular surface relative to the mating member.

13. The method of claim 12, wherein the elongate member is part of a bone restoration system including a first portion having an aperture therethrough, the method further comprising:

attaching the first portion of the system to the bone such that the apertures are generally aligned;

inserting the elongate member through the aperture in the first portion of the system to facilitate application of the at least one loading condition to the internal portion of the bone by the elongate member.

14. The method of claim 13, wherein the elongate member includes an electromechanical actuator, and wherein the step of applying the at least one loading condition to the internal portion of the bone includes providing electrical power to the actuator to effect a movement thereof.

15. The method of claim 14, wherein the bone restoration system further includes a compression member configured to cooperate with the first portion of the system, and wherein the step of applying the at least one loading condition to the internal portion of the bone includes inserting the compression member into the first portion of the system to contact the elongate member and apply a force thereto.

16. The method of claim 12, wherein applying at least one loading condition to the bone includes applying at least one of a static load or a cyclic load to the bone.

17. A system for effecting displacement of bone for restoration of a skeletal joint, the joint including a portion of the bone having an articular surface thereon and a mating member configured to cooperate with the articular surface of the bone, the articular surface being disposed at a first position relative to the mating member, the system comprising:

a first portion configured for attachment to the bone and having an aperture therethrough, the aperture in the first portion being configured to be generally aligned with an aperture in the bone to facilitate access through the apertures to an internal portion of the bone generally opposite the articular surface; and

a second portion configured for insertion into the apertures, the first and second portions cooperating such that the first portion supports the second portion as the second portion contacts the internal portion of the bone and applies a loading condition thereto to facilitate structural changes in the bone, including a change in the position of the articular surface relative to the mating member.

18. The system of claim 17, wherein the second portion includes an electromechanical actuator extensible in the presence of an electrical current.

19. The system of claim 18, wherein the electromechanical actuator is operable to extend cyclically, thereby facilitating application of a cyclic loading condition to the internal portion of the bone by the second portion.

20. The system of claim 17, further including a compression member configured to cooperate with the first portion of the system to apply a force to the second portion of the system, thereby facilitating the application of loading condition to the internal portion of the bone by the second portion.

21. The system of claim 20, wherein the first portion of the system includes a housing having internal and external threads, the housing being configured for insertion into the aperture in the bone, such that the external threads engage the bone, the compression member having external threads configured to cooperate with the internal threads in the housing for moving the compression member into and out of the housing, thereby respectively applying more and less force to the second member of the housing and facilitating control of the loading condition applied to the internal portion of the bone.

22. The system of claim 21, wherein the second portion of the system includes an extendable component including a material that is deformable when the loading condition is applied to the internal portion of the bone, thereby increasing a surface area of the extendable component and reducing the stress applied to the internal portion of the bone when the loading condition is applied.