Method and apparatus for use in balancing ligaments of a knee

• US 20060241569A1
• Filed: 03/31/2005
• Published: 10/26/2006
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Depuy Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Products Incorporated (Johnson & Johnson)
• Inventors: DiSilvestro, Mark R.
• Granted Patent: US 7,615,055 B2
• Time in Patent Office: Days
• US Class Current: 606/1
• CPC Class Codes: A61B 2017/0268 for the knee
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/461 of knees
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/4632 using computer-controlled surgery, e.g. robotic surgery
• CPC Class Codes: A61F 2002/4658 for measuring dimensions, e.g. length
• CPC Class Codes: A61F 2002/4666 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/4696 optical

Abstract

An apparatus for use in performing an orthopaedic surgical procedure on a patient includes at least one femoral paddle and a tibial paddle. At least one of the femoral paddle and the tibial paddle is movable away from the other. The apparatus also includes a sensor configured to generate a signal indicative of a force applied to the femoral paddle or the tibial paddle. The apparatus may be communicatively coupled to a computer assisted orthopaedic surgery system.

Claims

1. An apparatus for use in performing an orthopaedic surgical procedure on a patient, the apparatus comprising:

a tibial paddle configured to contact a proximal tibia of the patient;

a femoral paddle configured to contact a distal femur of the patient and positioned over the tibial paddle;

means for moving at least one of the femoral paddle and the tibial paddle away from the other; and

a sensor configured to generate an electrical output signal indicative of a force applied to at least one of the femoral paddle and the tibial paddle.

2. The apparatus of claim 1, wherein the means for moving the at least one of the femoral paddle and the tibial paddle includes an actuator operatively coupled to the at least one of the femoral paddle and the tibial paddle to move the at least one of the femoral paddle and the tibial paddle in response to a control signal.

3. The apparatus of claim 2, wherein the actuator is a stepper motor.

4. The apparatus of claim 2, wherein the actuator is a linear actuator.

5. The apparatus of claim 1, wherein the sensor is a load cell.

6. The apparatus of claim 1, further comprising a distance sensor configured to generate a distance signal indicative of a distance between the femoral and tibial paddles.

7. The apparatus of claim 1, further comprising a controller and a user interface, the controller configured to (i) receive the electrical output signal from the sensor, (ii) determine a force value based on the electrical output signal, and (iii) display the force value on the user interface.

8. The apparatus of claim 7, wherein the user interface includes a number of buttons.

9. The apparatus of claim 7, wherein the user interface includes a display.

10. The apparatus of claim 7, wherein the controller is responsive to user inputs received via the user interface to control the means for moving the at least one of the femoral paddle and the tibial paddle.

11. The apparatus of claim 7, wherein the controller includes a memory device and is configured to store a digital representation of the force applied to at least one of the femoral paddle and the tibial paddle based on the output signal.

12. The apparatus of claim 7, further comprising a distance sensor configured to generate an electrical distance signal indicative of a distance between the femoral and tibial paddles, and wherein the controller is configured to (i) receive the electrical distance signal, (ii) determine a distance value based on the electrical distance signal, and (iii) display the distance value on the user interface.

13. The apparatus of claim 12, wherein the controller includes a memory device and is configured to store a digital representation of the distance signal.

14. The apparatus of claim 13, wherein the controller is responsive to a user input received via the user interface to retrieve a stored distance value from the memory device and control the means for moving the at least one of the femoral paddle and the tibial paddle to move the at least one of the femoral paddle and the tibial paddle away from the other to a distance equal to the stored distance value.

15. The apparatus of claim 1, further comprising a transmitter configured to transmit measurement data.

16. The apparatus of claim 15, wherein the measurement data includes data indicative of the force applied to the femoral paddle.

17. The apparatus of claim 15, wherein the measurement data includes data indicative of a distance between the femoral paddle and the tibial paddle.

18. The apparatus of claim 1, further comprising a receiver configured to receive control signals from a computer assisted orthopedic surgical system.

19. The apparatus of claim 18, further comprising a controller communicatively coupled to the receiver and configured to control the means for moving the at least one of the femoral paddle and the tibial paddle in response to the control signals.

20. A method of operating a ligament balancer during the performance of an orthopaedic surgical procedure, the method comprising:

moving at least one of a femoral paddle and a tibial paddle away from the other; and

generating an electrical output signal indicative of a force applied to at least one of the femoral paddle and the tibial paddle.

21. The method of claim 20, further comprising generating an output signal indicative of the distance between the femoral paddle and the tibial paddle.

22. The method of claim 20, wherein the generating step includes transmitting data indicative of the force applied to the at least one of the femoral paddle and the tibial paddle to a computer assisted orthopaedic surgery system.

23. The method of claim 22, wherein transmitting data includes wirelessly transmitting the data.

24. The method of claim 20, wherein the moving step includes controlling an actuator coupled to the at least one of the femoral paddle and the tibial paddle.

25. The method of claim 20, further comprising the steps of:

retrieving a first force value from a memory device;

determining a second force value based on the electrical output signal; and

wherein the moving step includes moving the at least one of the femoral paddle and the tibial paddle away from the other until the second force value equals the first force value.

26. A ligament balancer comprising:

a paddle configured to contact a proximal femur of a patient; and

a sensor configured to generate an electrical output signal indicative of a force applied to the paddle.

27. A ligament balancer comprising:

a first paddle configured to contact a proximal tibia of a patient;

a second paddle configured to contact a distal femur of the patient, at least one of the first and second paddles being movable away from the other; and

a sensor configured to generate an electrical output signal indicative of a distance between the first and second paddles.

28. A ligament balancer comprising:

a paddle configured to contact a distal femur of a patient and movable between a first and second position; and

an electrically driven actuator configured to move the paddle between the first and second positions in response to a control signal.

29. The ligament balancer of claim 28, wherein the electrically driven actuator is a stepper motor.

30. The ligament balancer of claim 28, wherein the electrically driven actuator is a linear actuator.