Method for aligning a prosthesis

• US 7,922,774 B2
• Filed: 09/11/2007
• Issued: 04/12/2011
• Est. Priority Date: 09/11/2006
• Status: Active Grant

• Current Assignee: Orthocare Innovations, LLC
• Original Assignee: Orthocare Innovations, LLC
• Inventors: Boone, David Alan, Macomber, Ben Gilbert
• Primary Examiner(s): Isabella; David
• Assistant Examiner(s): Woznicki; Jacqueline
• Application Number:
  US11/853,711
• Publication Number:
  US 20080140221A1
• Time in Patent Office: 1,309 Days
• Field of Search: 623/27
• US Class Current: 623/27
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/66 Feet; Ankle joints
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2/76 Means for assembling, fitting or testing prostheses, e.g. for measuring or balancing, e.g. alignment means
• CPC Class Codes: A61F 2002/5021 for adjusting a position by translation along an axis
• CPC Class Codes: A61F 2002/5023 along two perpendicular axes
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/705 Electromagnetic data transfer for implantable prostheses A61F2250/0002
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/7645 for measuring torque, e.g. hinge or turning moment, moment of force
• CPC Class Codes: A61F 2002/7695 Means for testing non-implantable prostheses for testing implantable prostheses A61F2240/008; for implanting artificial joints A61F2/468
• CPC Class Codes: G01B 21/24 for testing alignment of axes
• CPC Class Codes: G01L 1/2218 the supports being of the column type, e.g. cylindric, adapted for measuring a force along a single direction
• CPC Class Codes: G01L 1/2231 the supports being disc- or ring-shaped, adapted for measuring a force along a single direction
• CPC Class Codes: G01L 5/162 of piezoresistors
• CPC Class Codes: G06F 30/17 Mechanical parametric or variational design

Abstract

A computerized prosthesis alignment system includes a transducer that can measure socket reactions in the anterior/posterior plane and the right/left planes, while canceling or reducing the transverse forces on the measurements of these socket reactions. In addition, the transducer is also capable of determining the axial load or weight experienced by the prosthesis. The computerized prosthesis alignment system is in communication with a host computer. The moment data from the transducer is interpreted by the user via a computer interface. The host computer includes memory for storing one or more applications. These applications receive data from the transducer, interpret the data with discrete algebraic or fuzzy logic algorithms, and display the output numerically and graphically. Applications may also interpret the data to provide analyses to the user for aligning the prosthesis.

Claims

1. A method for aligning a prosthesis, comprising:

coupling a transducer that measures moments in an anterior/posterior plane and right/left plane to a prosthesis, wherein the prosthesis includes a first load bearing surface that is supported on a second load bearing surface, wherein the surfaces provide articulation in the anterior/posterior plane and the right/left plane, and wherein the prosthesis has an initial alignment;

attaching the prosthesis to a patient;

obtaining signals representative of moments in the anterior/posterior plane and right/left plane as the patient walks along a line of progression;

comparing the signals representative of moments obtained during walking to a model of alignment;

determining a numeric estimation of a geometric misalignment of the prosthesis; and

making an adjustment to the prosthesis to change the initial alignment of the prosthesis to bring the initial alignment closer to the alignment represented by the model of alignment.

2. The method of claim 1, further comprising providing instructions that specify a manner of making the adjustment.

3. The method of claim 1, further comprising providing instructions that specify a direction and amount that one or more set screws are to be adjusted.

4. The method of claim 1, further comprising providing patient weight information.

5. The method of claim 1, further comprising applying to the moments a correction factor that accounts for angular deviation from the line of progression.

6. The method of claim 1, further comprising determining an initial contact of a step during walking and a toe-off of a step during walking and determining the anterior/posterior moment and the right/left moment during the step.

7. The method of claim 1, further comprising aligning the transducer along the line of progression prior to walking.

8. The method of claim 1, further comprising measuring an angular deviation of the transducer from the line of progression during walking.

9. The method of claim 1, further comprising replacing the transducer with a substitute pyramid adaptor that is similar in height to the transducer to maintain an alignment achieved with the transducer.

10. The method of claim 1, further comprising obtaining the height of the transducer.

11. The method of claim 1, further comprising obtaining the orientation of an inverted pyramid mounted to the transducer.

12. The method of claim 1, further comprising obtaining the weight of the patient automatically.

13. The method of claim 1, further comprising projecting a laser light, line, beam or spot parallel to the line of progression.

14. The method of claim 1, wherein the transducer comprises memory for storing information.

15. The method of claim 1, further comprising storing information in memory housed in the transducer.