Systems and methods for joint replacement

• US 9,339,226 B2
• Filed: 01/21/2011
• Issued: 05/17/2016
• Est. Priority Date: 01/21/2010
• Status: Active Grant

• Current Assignee: Orthalign, Inc.
• Original Assignee: Orthalign, Inc.
• Inventors: van der Walt, Nicholas, Shapiro, Charles, Ryan, Matt, Nash, Sean
• Primary Examiner(s): Stout, Michael C
• Application Number:
  US13/011,815
• Publication Number:
  US 20110208093A1
• Time in Patent Office: 1,943 Days
• Field of Search: 606/130, 606/131, 606/88, 606/89, 606/102, 600/595
• US Class Current: 1/1
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2034/2048 using an accelerometer or inertia sensor
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/1071 measuring angles, e.g. using goniometers A61B5/1123 takes precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 90/10 for stereotaxic surgery, e.g. frame-based stereotaxis
• CPC Class Codes: A61B 90/11 with guides for needles or instruments, e.g. arcuate slides or ball joints
• CPC Class Codes: A61B 90/13 guided by light, e.g. laser pointers

Abstract

Systems and methods for joint replacement are provided. The systems and methods include a surgical orientation device, a reference sensor device, and at least one orthopedic fixture. The surgical orientation device, reference sensor device, and orthopedic fixtures can be used to locate the orientation of an axis in the body, to adjust an orientation of a cutting plane or planes along a bony surface, or otherwise to assist in an orthopedic procedure(s).

Claims

1. A method of determining an anatomical feature during a knee procedure, comprising:

coupling an orientation system with a distal aspect of a femur, the orientation system comprising a housing, a first orientation sensor and a second orientation sensor disposed within the housing, and a user interface operably coupled with the first orientation sensor and the second orientation sensor;

wherein the first orientation sensor is selected from the group of sensor types consisting of;

gyroscopic sensor, accelerometer sensor, tilt sensor, and magnetometer, and the second orientation sensor is selected from the group of sensor types consisting of;

gyroscopic sensor, accelerometer sensor, tilt sensor, and magnetometer;

wherein the first orientation sensor is a different sensor type than the second orientation sensor;

estimating a first error associated with the first orientation sensor based in part upon the output of the second orientation sensor;

estimating a second error associated with the second orientation sensor based in part upon the output of the first orientation sensor;

moving the orientation system to collect data indicative of the anatomical feature relevant to the knee procedure; and

reducing error from the data.

2. The method of claim 1, wherein estimating the second error includes estimating static bias in the second orientation sensor.

3. The method of claim 2, wherein estimating static bias further comprises maintaining the position of the orientation system for a minimum period.

4. The method of claim 1, further comprising, at the end of the moving step, returning the orientation system toward the position of the orientation system prior to the beginning of the moving step.

5. The method of claim 4, wherein the orientation system is configured to determine whether the user has returned the orientation system to a position that is approximately the same as the position of the orientation system prior to the beginning of the moving step.

6. The method of claim 5, wherein the orientation system comprises a filter with a minimum threshold to prevent a false stop indication.

7. The method of claim 1, wherein the moving step comprises moving in a loop configuration to collect data indicative of the anatomical feature relevant to the knee procedure.

8. The method of claim 7, wherein the moving step produces abduction of at least about 20 degrees while moving in the loop configuration.

9. The method of claim 1, wherein the first orientation sensor includes an accelerometer and estimating the first error includes estimating a gravity component of the accelerometer output.

10. The method of claim 9, further comprising determining, based upon a portion of the accelerometer output excluding the gravity component, the orientation of one or more of the housing and the femur.

11. The method of claim 1, further comprising:

coupling an orthopedic orientation assembly with the femur, the orthopedic orientation assembly comprising a reference device and the orientation system;

maintaining the position of the reference device relative to the femur while moving the orientation system to collect data.

12. The method of claim 1, wherein the data is indicative of the mechanical axis of the leg.

13. The method of claim 11, further comprising:

positioning, based upon the collected data, a cutting guide coupled with the orthopedic orientation assembly; and

cutting the femur at an angle corresponding to the position of the cutting guide.

14. The method of claim 13, comprising calculating a relative difference in orientation between the orientation system and the reference device prior to positioning the cutting guide.

16. The method of claim 1, wherein when moving the orientation system, maintaining a minimum average rate of motion of the orientation system.

17. The method of claim 16, wherein the minimum average rate of motion is at least 10 degrees per second about an axis of rotation.

15. A method of determining an anatomical feature during a knee procedure, comprising:

coupling an orientation system with a distal aspect of a femur, the orientation system comprising a first housing, a first orientation sensor disposed within the first housing, and a user interface operably coupled with the first orientation sensor;

coupling a reference system with a distal aspect of a femur, the reference system comprising a second housing, a second orientation sensor disposed within the second housing, wherein the orientation system and the reference system are separately moveable relative to each other;

interacting with the user interface to begin an analysis of potential sources of error in the orientation system after coupling the orientation system and the reference system to the distal femoral aspect;

moving the orientation system to collect data indicative of the anatomical feature;

estimating a first error associated with the first orientation sensor when the conditions of the second orientation sensor are known; and

estimating a second error associated with the second orientation sensor when the conditions of the first orientation sensor are known.

21. The method of claim 15, wherein the orientation system is configured to determine whether the user has returned the orientation system to a position that is approximately the same as the position of the orientation system prior to the beginning of the moving step.

22. The method of claim 15, wherein when moving the orientation system, maintaining a minimum average rate of motion of the orientation system.

23. The method of claim 22, wherein the minimum average rate of motion is at least 10 degrees per second about an axis of rotation.

18. A method of determining an anatomical feature during a knee procedure, comprising:

coupling an orientation system with a distal aspect of a femur, the orientation system comprising a housing, a first orientation sensor and a second orientation sensor disposed within the housing, and a user interface operably coupled with the first orientation sensor and the second orientation sensor;

estimating a first error associated with the first orientation sensor based in part upon the output of the second orientation sensor;

estimating a second error associated with the second orientation sensor based in part upon the output of the first orientation sensor;

moving the orientation system to collect data indicative of the anatomical feature relevant to the knee procedure; and

reducing error from the data,

wherein the second orientation sensor includes a gyroscope and estimating the second error is based in part upon the output of the first orientation sensor at substantially zero velocity.

19. A method of determining an anatomical feature during a knee procedure, comprising:

coupling an orientation system with a distal aspect of a femur, the orientation system comprising a housing, a first orientation sensor and a second orientation sensor disposed within the housing, and a user interface operably coupled with the first orientation sensor and the second orientation sensor;

estimating a first error associated with the first orientation sensor based in part upon the output of the second orientation sensor;

estimating a second error associated with the second orientation sensor based in part upon the output of the first orientation sensor;

moving the orientation system to collect data indicative of the anatomical feature relevant to the knee procedure; and

reducing error from the data,

wherein the first orientation sensor is an accelerometer and the second orientation sensor is a gyroscope.

20. A method of determining an anatomical feature during a knee procedure, comprising:

coupling an orientation system with a distal aspect of a femur, the orientation system comprising a housing, an inertial sensor assembly including an accelerometer and a gyroscope disposed within the housing, and a user interface operably coupled with the accelerometer and the gyroscope;

moving the orientation system to collect data indicative of the anatomical feature relevant to the knee procedure, wherein when moving the orientation system, the accelerometer generates an output;

estimating an error of the accelerometer by comparing a position or an orientation value derived from the output of the accelerometer to an expected position or orientation value based at least in part on the known conditions of the gyroscope; and

reducing the error contributed by the accelerometer from the data.