Universal tibial augment
A prosthetic knee system has a tibial component and a universal augment. A single augment can be used to support the tibial tray on either the medial or lateral side. The augment has reverse image sides and a through-bore with no threads. The tibial tray has a complementary threaded bore. The through-bore of the augment has a plane of symmetry perpendicular to its central longitudinal axis.
1. A universal tibial augment comprising:
a first surface;
a second surface;
a thickness between the first surface and the second surface and a through-bore extending from the first surface to the second surface;
wherein the through-bore has a central longitudinal axis and includes a first countersink at the first surface, a second countersink at the second surface and a smooth neck connecting the first and second countersinks;
wherein the augment includes inner tapered surfaces defining the first and second countersinks and a smooth inner cylindrical surface defining the neck;
wherein the shape and dimensions of the inner tapered surfaces defining the first and second countersinks are substantially the same; and
wherein the augment is part of a kit, the kit further comprising: a tibial component, a tibial bearing and a femoral component.
2. The universal tibial augment of claim 1 wherein the augment comprises a tibial block.
3. The universal tibial augment of claim 1 wherein the first and second surfaces of the augment are substantially parallel to each other.
4. The universal tibial augment of claim 1 wherein the augment is reversible.
5. A prosthetic tibial system comprising:
a tibial component including a tibial tray having a proximal side and a distal side and a stem extending outward from the distal side, wherein the tibial tray has a plane of symmetry extending through the stem and the proximal side, the tibial tray including a threaded bore on each side of the plane of symmetry extending from the distal side toward the proximal side; and
a universal tibial augment for mounting on the distal side of the tibial tray, the tibial augment having a first side, a second side opposite the first side, a thickness between the first side and the second side and a through-bore extending from the first side to the second side;
wherein the tibial augment is mountable on the distal surface of the tibial tray on both sides of the plane of symmetry of the tibial tray; and
wherein the through-bore of the universal tibial augment has a central longitudinal axis and a plane of symmetry perpendicular to the central longitudinal axis.
6. The prosthetic tibial system of claim 5 wherein the tibial augment is mountable to the distal side of the tibial tray with the first side of the tibial augment against the distal side of the tibial tray and also mountable to the distal side of the tibial tray with the second side of the tibial augment against the distal side of the tibial tray.
7. The system of claim 5 wherein the augment includes a smooth inner cylindrical surface defining a reduced diameter neck in the through-bore.
8. The system of claim 5 wherein the first side of the augment is substantially parallel to the second side of the augment.
9. The system of claim 5 wherein the tibial augment is reversible.
10. The system of claim 5 wherein the system is part of a kit, the kit further comprising: a femoral component and a tibial bearing.