DISTRACTOR INSTRUMENT

• US 20090270869A1
• Filed: 09/21/2006
• Published: 10/29/2009
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Depuy International Limited (Johnson & Johnson)
• Original Assignee: Depuy International Limited (Johnson & Johnson)
• Inventors: Rock, Michael, Colquhoun, Callum
• Granted Patent: US 9,498,199 B2
• Time in Patent Office: Days
• US Class Current: 606/88
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia
• CPC Class Codes: A61B 2017/0268 for the knee
• CPC Class Codes: A61B 2090/061 for measuring dimensions, e.g. length

Abstract

A distractor instrument for use in knee joint surgery is provided that includes a tibial plate, a femoral plate, a tibial arm having a plate end and a control end, wherein the tibial plate is fastened to the plate end of the tibial arm at its anterior edge, and wherein, when the tibial plate is engaged with the tibia, the tibial arm is configured to extend from the tibial plate generally medially or laterally of the knee joint. The distractor instrument also includes a femoral arm having a plate end and a control end, wherein the femoral plate is fastened to the plate end of the femoral arm, and wherein, when the femoral plate is engaged with the femur, the femoral arm extends from the femoral plate generally aligned with the tibial arm. The tibial arm and the femoral arm are pivotably connected to one another at a point between their respective plate and control ends so that pivotal movement of the femoral arm relative to the tibial arm reduces the distance between their control ends and causes the distance between the tibial plate end and the femoral plate end to increase.

Claims

1. A distractor instrument for use in knee joint surgery, comprising:

a tibial plate;

a femoral plate;

a tibial arm having a plate end and a control end, wherein the tibial plate is fastened to the plate end of the tibial arm at its anterior edge, and wherein, when the tibial plate is engaged with the tibia, the tibial arm is configured to extend from the tibial plate generally medially or laterally of the knee joint;

a femoral arm having a plate end and a control end, wherein the femoral plate is fastened to the plate end of the femoral arm, and wherein, when the femoral plate is engaged with the femur, the femoral arm extends from the femoral plate generally aligned with the tibial arm; and

wherein the tibial arm and the femoral arm are pivotably connected to one another at a point between their respective plate and control ends so that pivotal movement of the femoral arm relative to the tibial arm to reduce the distance between their control ends causes the distance between the tibial plate end and the femoral plate end to increase.

2. The instrument of claim 1, further comprising a device configured to lock the tibial arm and the femoral arm against relative movement between the tibial arm and the femoral arm that produces a reduction of the distance between the plate ends of the tibial arm and the femoral arm.

3. The instrument of claim 1, further comprising a biasing device that acts on the tibial and femoral arms so as to reduce the distance between the tibial plate end and the femoral plate end.

4. The instrument of claim 1, wherein the femoral plate is fastened to the femoral arm by means of a pin that extends from the femoral arm along the anterior-posterior axis, and wherein the femoral plate is configured to rotate about the pin.

5. The instrument of claim 1, further comprising an ancillary instrument configured to be mounted on the distractor instrument using complimentary formations of a spigot and socket assembly on one of the ancillary and distractor instruments.

6. The instrument of claim 5, wherein the spigot is in the form of a plate and the socket is in the form of a slot in which the plate is configured to be received.

7. The instrument of claim 5, wherein the formation of the spigot and socket assembly provided on the distractor instrument is provided on the tibial arm.

8. The instrument of claim 5, wherein the ancillary instrument is selected from:

a probe for contacting the femur to measure the gap between the tibia and the femur,

a cutting guide that has a slot formed therein for receiving the blade of a saw or other cutting device, and

a pin guide having at least one hole extending therethrough to define the location for a hole that is to be prepared in the femur.