Orthopaedic Implant Load Sensor And Method Of Interpreting The Same

• US 20090005708A1
• Filed: 06/30/2008
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• Status: Abandoned Application

• Current Assignee: Douglas L. Cerynik, Norman A. Johanson
• Original Assignee: Douglas L. Cerynik, Norman A. Johanson
• Inventors: Johanson, Norman A., Cerynik, Douglas L.
• Application Number:
  US12/164,744
• Publication Number:
  US 20090005708A1
• Time in Patent Office: Days
• US Class Current: 600/587
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61F 2/3877 Patellae or trochleae
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/3067 for data transfer
• CPC Class Codes: A61F 2250/0002 for data transfer

Abstract

Joint implant sensors, methods of using the same, and methods of aligning permanent implants are described herein. A device for providing intraoperative in vivo diagnostics of loads having at least one load sensor associated with the implant, and at least one signal processing device operatively coupled with the sensors. The signal processing device is operable to receive the output signal from the sensors and transmit a corresponding signal.

Claims

1. A sensor device comprising:

a base plate having

a base plate bottom surface adapted to contact a joint surface, and

a base plate top surface;

a conformable sensor including

a sensor matrix that includes individual sensor elements, and

a conformable mat,

wherein the conformable mat supports the sensor matrix;

an implant having an implant bottom surface and an implant top surface,

the conformable sensor operably connected to the implant and being associated with either the base plate top surface, the implant bottom surface, the implant top surface, or the base plate top surface and the implant bottom surface,

the base plate top surface facing and operatively connected to the implant bottom surface.

2. The sensor device of claim 1, further comprising a data transmission device, wherein the sensor matrix collects joint data and the data transmission device transmits the joint data from the sensor matrix to a data processor.

3. The sensor device of claim 2, the joint data comprises data selected from the group consisting of stress, pressure, and force data.

4. The sensor device of claim 1, wherein at least a portion of the conformable sensor is embedded in the implant.

5. The sensor device of claim 1, wherein the conformable sensor is integral with the implant.

6. The sensor device of claim 1, wherein at least a portion of the sensor matrix is embedded in the conformable mat.

7. The sensor device of claim 1, the implant top surface having a dome-shape.

8. The sensor device of claim 1, wherein the individual sensor elements include a force sensor selected from the group consisting of a pressure sensor, a pressure transducer, a capacitive transducer, a capacitive sensor, a resistive sensor, a piezoelectric sensor, a force transducer, a strain gauge, and a microelectromechanical contact stress sensor.

9. The sensor device of claim 1, wherein the force sensor is a capacitive sensor.

10. The sensor device of claim 1, wherein the force sensor is a piezoelectric sensor.

11. The sensor device of claim 1, wherein the force sensor is a force transducer.

12. The sensor device of claim 1, wherein the sensor device is shaped like a patellar implant.

13. A sensor device comprising:

a base plate having

a base plate bottom surface adapted to contact a joint surface, and

a base plate top surface;

a conformable including a sensor matrix that includes individual sensor elements arranged in a conformable mat,

an implant having an implant bottom surface and an implant top surface,

the conformable sensor being operably connected to the implant and associated with either the base plate top surface, the implant bottom surface, the implant top surface, or the base plate top surface and the implant bottom surface,

the base plate top surface facing and operatively connected to the implant bottom surface.

14. The sensor device of claim 13, further comprising a data transmission device, wherein the sensor matrix collects joint data and the data transmission device transmits the joint data from the sensor matrix to a data processor.

15. The sensor device of claim 14, the joint data comprising data selected from the group consisting of stress, pressure, and force data.

16. The sensor device of claim 13, wherein at least a portion the conformable sensor is embedded within the implant.

17. The sensor device of claim 13, the implant top surface having a dome-shape.

18. The sensor device of claim 13, wherein the individual sensor elements include a force sensor selected from the group consisting of a pressure sensor, a pressure transducer, a capacitive transducer, a capacitive sensor, a resistive sensor, a piezoelectric sensor, a force transducer, a strain gauge, and a microelectromechanical contact stress sensor.

19. The sensor device of claim 13, wherein the force sensor is a capacitive sensor.

20. The sensor device of claim 13, wherein the force sensor is a piezoelectric sensor.

21. The sensor device of claim 13, wherein the force sensor is a force transducer.

22. The sensor device of claim 13, wherein the sensor device is shaped like a patellar implant.

23. A method of using a sensor device to measure joint characteristics during joint replacement or joint implant revision, the method comprising:

a) providing sensor device including

a base plate having a base plate bottom surface adapted to contact a joint surface, and a base plate top surface;

a conformable sensor including a sensor matrix that includes individual sensor elements; and

a conformable mat, the conformable mat supports the sensor matrix;

an implant having an implant bottom surface and an implant top surface, the conformable sensor being operably connected to the sensor implant and associated with either the base plate top surface, the implant bottom surface, the implant top surface, or the base plate top surface and the implant bottom surface, the base plate top surface facing and operatively connected to the implant bottom surface,

b) making an incision in a patient to expose the joint and removing one of the group consisting of bone and pre-existing implants,

c) inserting the sensor device and remaining joint implants required for the joint replacement or joint implant revision into the joint,

d) moving the joint through a partial or full range of motion,

e) collecting joint data through the sensor matrix,

f) making necessary adjustments based on the joint data,

g) repeating steps d)-f) until the joint, the sensor implant, and the remaining joint implants are in a desirable position,

h) removing the sensor device,

i) inserting a final implant in place of the sensor device, and

j) closing the incision.

24. The method of claim 23, further comprising, between b) and c), adjusting bone surface as needed.

25. The method of claim 24, wherein adjusting the bone surface further comprises cutting bone spurs from bones on the joint surface.

26. The method of claim 23, wherein f) further comprises at least one of adjusting the joint, soft tissue, the remaining joint implants, and the sensor device based on the joint data.

27. The method of claim 23, wherein the sensor device is shaped like a patella and the final implant is a patellar implant.

28. A sensor device comprising:

a base plate having

a base plate bottom surface adapted to contact a joint surface, and

a base plate top surface;

a conformable sensor including

a sensor matrix that includes individual sensor elements, and

a conformable mat,

wherein the conformable mat supports the sensor matrix;

an implant having an implant bottom surface and an implant top surface,

the conformable sensor operably connected to the implant and being associated with either the base plate top surface, the implant bottom surface, the implant top surface, or the base plate top surface and the implant bottom surface,

the base plate top surface facing and operatively connected to the implant bottom surface;

the sensor device further comprising a transceiver and antenna to wirelessly transmit data to a data processor or wirelessly receive communications.

29. A joint replacement implant collection comprising:

i) a sensor device shaped in the form of a final implant that will be associated with one bone within a joint, the sensor device including

a base plate having

a base plate bottom surface adapted to contact a joint surface, and

a base plate top surface;

a conformable sensor including

a sensor matrix that includes individual sensor elements, and

a conformable mat,

wherein the conformable mat supports the sensor matrix;

an implant having an implant bottom surface and an implant top surface,

the conformable sensor operably connected to the implant and being associated with either the base plate top surface, the implant bottom surface, the implant top surface, or the base plate top surface and the implant bottom surface,

the base plate top surface facing and operatively connected to the implant bottom surface; and

ii) remaining implants in the form of implants associated with the remaining bones in the joint.

30. The joint replacement implant collection of claim 29, wherein the sensor device is shaped like a patellar implant.

31. The joint replacement implant collection of claim 29, wherein the sensor device is also the final implant.

32. The joint replacement implant collection of claim 31, wherein the sensor device further comprises a transceiver and antenna for wireless communications.

33. The joint replacement implant collection of claim 29, wherein the sensor device further comprises a transceiver and antenna for wireless communications.

34. A joint replacement implant collection comprising:

i) a sensor device shaped in the form of a final implant that will be associated with one bone within a joint, the sensor device including

a base plate having

a base plate bottom surface adapted to contact a joint surface, and

a base plate top surface;

a conformable sensor including

a sensor matrix that includes individual sensor elements arranged in a conformable mat;

an implant having an implant bottom surface and an implant top surface,

the conformable sensor operably connected to the implant and being associated with either the base plate top surface, the implant bottom surface, the implant top surface, or the base plate top surface and the implant bottom surface,

the base plate top surface facing and operatively connected to the implant bottom surface; and

ii) remaining implants in the form of implants associated with the remaining bones in the joint.

35. The joint replacement implant collection of claim 34, wherein the sensor device is shaped like a patellar implant.

36. The joint replacement implant collection of claim 34, wherein the sensor device is also the final implant.

37. The joint replacement implant collection of claim 36, wherein the sensor device further comprises a transceiver and antenna for wireless communications.

38. The joint replacement implant collection of claim 34, wherein the sensor device further comprises a transceiver and antenna for wireless communications.