Knee ligament balancer

• US 8,562,617 B2
• Filed: 05/23/2012
• Issued: 10/22/2013
• Est. Priority Date: 06/27/2008
• Status: Active Grant

• Current Assignee: DePuy Synthes Products LLC (Johnson & Johnson)
• Original Assignee: DePuy Synthes Products LLC (Johnson & Johnson)
• Inventors: Chessar, Ryan, Drummond, James, Ruhling, Marc E.
• Primary Examiner(s): Schaper, Michael T
• Application Number:
  US13/478,661
• Publication Number:
  US 20120238911A1
• Time in Patent Office: 517 Days
• Field of Search: 606/86.R, 606/87, 606/88, 606/90, 606/102, 606/105
• US Class Current: 606/88
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 2017/0268 for the knee
• CPC Class Codes: A61B 5/103 Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes A61B5/08 takes precedence; measuring aids for tailors A41H1/00; measuring instruments specially adapted for dentistry A61C19/04
• CPC Class Codes: A61B 5/4533 Ligaments
• 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 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/3052 unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30528 Means for limiting said movement
• CPC Class Codes: A61F 2002/30566 Helical springs
• 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 2002/469 electrical
• CPC Class Codes: A61F 2002/4696 optical
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit

Abstract

An orthopaedic surgical device comprises a first sensor component and a second sensor component. Each sensor component includes a paddle set to contact a proximal tibia and a distal femur of a patient. The first sensor component and the second sensor component being movable with respect to one another to extend one paddle set beyond the other paddle set, and each paddle set includes cutouts for the clearance of the patellar tendon to avoid the need to evert the patella during use.

Claims

1. A method for balancing a knee, comprising:

extending posterior ends of a first paddle set beyond posterior ends of a second paddle set along a general direction of extension, the first paddle set and the second paddle set being connected and slidable along the general direction of extension,

inserting the posterior ends of the first paddle set and the second paddle set into a side of the knee without everting a patella of the knee,

contacting, with the posterior ends of the first paddle set, portions of a proximal tibia and a distal femur that lie away from the side of the knee into which the posterior ends of the first paddle set were inserted, and

contacting, with the posterior ends of the second paddle set, portions of the proximal tibia and the distal femur that lie toward the side of the knee into which the posterior ends of the second paddle set were inserted.

2. The method of claim 1, wherein extending posterior ends of a first paddle set includes sliding the first paddle set with respect to the second paddle set in the general direction of extension.

3. The method of claim 1, wherein inserting the posterior ends of the first paddle set and the second paddle set into a side of the knee includes inserting the posterior ends of the first paddle set and the second paddle set into a medial side of the knee.

4. The method of claim 3, wherein:

contacting, with the posterior ends of the first paddle set, portions of a proximal tibia and a distal femur that lie away from the side of the knee into which the posterior ends of the first paddle set were inserted includes contacting a portion of the proximal tibia and a portion of the distal femur that lie toward a lateral side of the knee, and

contacting, with the posterior ends of the second paddle set, portions of the proximal tibia and the distal femur that lie toward the side of the knee into which the posterior ends of the second paddle set were inserted includes contacting a portion of the proximal tibia and a portion of the distal femur that lie toward the medial side of the knee.

5. The method of claim 1, wherein inserting the posterior ends of the first paddle set and the second paddle set into a side of the knee includes inserting the posterior ends of the first paddle set and the second paddle set into a lateral side of the knee.

6. The method of claim 5, wherein:

contacting, with the posterior ends of the first paddle set, portions of a proximal tibia and a distal femur that lie away from the side of the knee into which the posterior ends of the first paddle set were inserted includes contacting a portion of the proximal tibia and a portion of the distal femur that lie toward a medial side of the knee, and

contacting, with the posterior ends of the second paddle set, portions of the proximal tibia and the distal femur that lie toward the side of the knee into which the posterior ends of the second paddle set were inserted includes contacting a portion of the proximal tibia and a portion of the distal femur that lie toward the lateral side of the knee.

7. The method of claim 1, further comprising:

measuring a first displacement between portions of the proximal tibia and the distal femur using the first paddle set, and

measuring a second displacement between portions of the proximal tibia and the distal femur using the second paddle set.

8. The method of claim 1, further comprising:

selecting a first force,

applying the first force between portions of the proximal tibia and the distal femur using the first paddle set,

selecting a second force, and

applying the second force between portions of the proximal tibia and the distal femur using the second paddle set.

9. The method of claim 8, wherein:

the first force is dependent upon a displacement between an upper end of a first displacement cylinder and a lower end of a first tensor cylinder, and

the second force is dependent upon a displacement between an upper end of a second displacement cylinder and a lower end of a second tensor cylinder.

10. The method of claim 9, wherein:

selecting the first force includes moving the first tensor cylinder in relation to the first displacement cylinder, and

selecting the second force includes moving the second tensor cylinder in relation to the second displacement cylinder.

11. The method of claim 10, wherein:

moving the first tensor cylinder includes unlocking the first tensor cylinder, and

moving the second tensor cylinder includes unlocking the second tensor cylinder.

12. The method of claim 8, further comprising:

outputting an indication of the first force to a user interface, and

outputting an indication of the second force to a user interface.

13. The method of claim 12, wherein:

the indication of the first force includes a first range of forces in which the first force lies, and

the indication of the second force includes a second range of forces in which the second force lies.

14. The method of claim 13, wherein:

the first range of forces is selected from a plurality of force ranges, and

the second range of forces is selected from the plurality of force ranges.

15. The method of claim 8, further comprising:

measuring a first displacement between portions of the proximal tibia and the distal femur using the first paddle set while applying the first force between portions of the proximal tibia and the distal femur, and

measuring a second displacement between portions of the proximal tibia and the distal femur using the second paddle set while applying the second force between portions of the proximal tibia and the distal femur.

16. A method for balancing a knee, comprising:

extending posterior ends of a first paddle set beyond posterior ends of a second paddle set along a general direction of extension, the first paddle set and the second paddle set being connected and slidable along the general direction of extension,

inserting the posterior ends of the first paddle set and the second paddle set into a medial side of the knee without everting a patella of the knee,

contacting, with the posterior ends of the first paddle set, portions of a proximal tibia and a distal femur that lie away from the medial side of the knee, and

contacting, with the posterior ends of the second paddle set, portions of the proximal tibia and the distal femur that lie toward the medial side of the knee.

17. The method of claim 16, further comprising:

selecting a first force,

applying the first force between portions of the proximal tibia and the distal femur using the first paddle set,

measuring a first displacement between portions of the proximal tibia and the distal femur using the first paddle set while applying the first force,

selecting a second force,

applying the second force between portions of the proximal tibia and the distal femur using the second paddle set, and

measuring a second displacement between portions of the proximal tibia and the distal femur using the second paddle set while applying the second force.

18. A method for balancing a knee, comprising:

extending posterior ends of a first paddle set beyond posterior ends of a second paddle set along a general direction of extension, the first paddle set and the second paddle set being connected and slidable along the general direction of extension,

inserting the posterior ends of the first paddle set and the second paddle set into a lateral side of the knee without everting a patella of the knee,

contacting, with the posterior ends of the first paddle set, portions of a proximal tibia and a distal femur that lie away from the lateral side of the knee, and

contacting, with the posterior ends of the second paddle set, portions of the proximal tibia and the distal femur that lie toward the lateral side of the knee.

19. The method of claim 18, further comprising:

selecting a first force,

applying the first force between portions of the proximal tibia and the distal femur using the first paddle set,

measuring a first displacement between portions of the proximal tibia and the distal femur using the first paddle set while applying the first force,

selecting a second force,

applying the second force between portions of the proximal tibia and the distal femur using the second paddle set, and

measuring a second displacement between portions of the proximal tibia and the distal femur using the second paddle set while applying the second force.