DISTRACTOR SYSTEM

• US 20070233144A1
• Filed: 06/07/2006
• Published: 10/04/2007
• Est. Priority Date: 03/20/2006
• Status: Active Grant

• Current Assignee: Omnilife Science, Inc. (OrthoUnited, Inc.)
• Original Assignee: Perception Raisonnement Action en Medecine
• Inventors: Plaskos, Christopher, Lavallee, Stephane
• Granted Patent: US 8,231,631 B2
• Time in Patent Office: Days
• US Class Current: 606/90
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 2017/0268 for the knee

Abstract

A medical instrument includes a base; an upper member; and a linkage mechanism coupled to the base and the upper member and being operable to maintain the upper member in a variable fixed position that is substantially parallel to the base and spaced a predetermined, variable distance therefrom, wherein the linkage mechanism includes at least three linkage elements that are arranged at angles relative to one another such that when one link element opens, the other link elements open with at an equal angle resulting in the upper member being constrained to remain parallel to the base.

Claims

1. A medical instrument comprising:

a base;

an upper member; and

a linkage mechanism coupled to the base and the upper member and being operable to maintain the upper member in a variable fixed position that is substantially parallel to the base and spaced a predetermined, variable distance therefrom, wherein the linkage mechanism includes at least three linkage elements that are arranged at angles relative to one another such that when one link element opens, the other link elements open with at an equal angle resulting in the upper member being constrained to remain parallel to the base.

2. The instrument of claim 1, wherein the base includes a first base plate and a second base plate that is pivotably coupled to the first base plate, wherein at least a portion of the first and second base plates lie in the same plane.

3. The instrument of claim 2, wherein each of the base plates includes a main portion and a raised portion connected thereto by an inclined portion, the main portions of the first and second base plates lying in the same plane.

4. The instrument of claim 3, wherein the first and second base plates are pivotally connected to one another by a pivot joint that formed in the raised portions of the first and second base plates.

5. The instrument of claim 1, wherein the upper part has an upper surface configured to support a mass.

6. The instrument of claim 5, wherein the upper surface has a concave shape and the mass comprises a bone.

7. The instrument of claim 1, wherein the device is a knee distraction device and is formed of a pair of base plates and the upper part is formed of a pair of upper femoral plateau members that support condyles of a femur.

8. The instrument of claim 1, further including a controller operably coupled to the linkage mechanism to cause the controlled movement thereof resulting in movement of the upper part relative to the base.

9. The instrument of claim 8, wherein the controller is operably connected to an adjustable spacer element that has a body disposed around the linkage mechanism, the body being fluidly connected to a fluid source such that controlled delivery of fluid to the body results in expansion of the spacer element and a distance between the upper part and base increasing.

10. The instrument of claim 9, wherein the body of the spacer element comprises an expandable pouch that has a hollow interior in which the linkage mechanism is disposed, the pouch being secured to the upper part and the base by means of fastening elements.

11. The instrument of claim 10, wherein the linkage mechanism includes features formed therein to receive the fastening elements to accommodate movement of the linkage mechanism and the pouch over a range of motion for the device.

12. The instrument of claim 1, wherein the linkage mechanism comprises three linkage elements, each of which comprises a pair of links, with one link of the pair being pivotally coupled to the upper part and the other link of the pair being pivotally coupled to the base.

13. The instrument of claim 1, further including a pair of intermediate plates securely attached to the upper part and the base, with the linkage mechanism being disposed between the pair of intermediate plates.

14. The instrument of claim 1, wherein a minimum spacing between external surfaces the upper part and the base being less than 10 millimeters.

15. A distraction device for use in a surgical application to space one bone a predetermined distance from another bone comprising:

a base;

an upper member; and

a linkage mechanism coupled to the base and the upper member and being operable to maintain the upper member in a variable fixed position that is substantially parallel to the base and spaced a predetermined, variable distance therefrom, wherein the linkage mechanism includes at least three linkage elements that are arranged at angles relative to one another such that when one link element opens, the other link elements open with at an equal angle resulting in the upper member being constrained to remain parallel to the base.