Systems and methods for installing ankle replacement prostheses
View Patent ↗An ankle implant for use in ankle arthroplasty in total ankle replacement is provided. The implant includes an upper prosthesis anchored to the tibia and a lower prosthesis anchored to the talus. The lower prosthesis is operable associated with the upper prosthesis. The implant also includes a stem which is rigidly removably connected to the second member. The stem includes a portion for attachment to the calcaneous. The stem is be adapted to be in a first position in the calcaneous when the stem is in a first relative position with respect to the lower prosthesis, and to provide for a second position in the calcaneous when the stem is in a second relative position with respect to the lower prosthesis.
1. A prosthesis, comprising:
a tibial stem having a cylindrical body, the tibial stem having a sufficient length such that an end projects from an end of a tibia when the tibial stem is disposed within an intradmedullary channel formed in the tibia;
a first dome having a substantially flat inner surface and a concave outer surface forming an articulating joint surface, the substantially flat inner surface defining an aperture configured to be engaged by the end of the tibial stem;
a sleeve defining an opening having a diameter sufficient to slidably receive the tibial stem therein, the sleeve having at least one anti-rotational feature extending from an exterior surface;
a plate having a first portion defining an aperture and configured to be coupled to a planar surface formed on a top of a talus, the plate including an overhang extending from the first portion of the plate at angle such that the overhang extends from a top of the talus to overlap at least a portion of a calcaneus when the first portion of the plate is coupled to the planar surface formed on the top of the talus;
a talo-calcaneal stem having a cylindrical body having a length sufficient to extend from the top of the talus into the calcaneus such that an end of the talo-calcaneal stem projects at an angle from the body through the aperture in the plate and to a position exterior to the talus when the talo-calcaneal stem is disposed in an intramedullary channel formed through the talus and calcaneus; and
a second dome having an upper surface and a substantially flat lower surface, the upper surface having a convex surface configured to form a complementary articulating joint surface with the concave outer surface of the first dome, the lower surface defining an aperture having a diameter sufficient to receive the end of the talo-calcaneal therein.
2. The implant of claim 1 , wherein the at least one anti-rotational feature includes an outwardly extending fin.
3. The implant of claim 1 , wherein the talo-calcaneal stem extends from the plate at an angle with respect to a plane defined by the plate.
4. The implant of claim 1 , wherein the first dome and the second dome are sized and configured to articulate with each other.
5. The implant of claim 1 , wherein the first dome and the tibial stem together form an upper prosthetic body, and wherein the upper prosthetic body includes at least one derotation peg extending-from the upper prosthetic body.
6. An ankle implant, comprising:
an upper prosthesis, including
a tibial stem sized and configured to be received within a tibia,
a concave dome defining a concave surface, and
at least one derotation peg extending from the upper prosthesis and configured to engage the tibia;
a lower prosthesis, including:
a talo-calcaneal stem having a cylindrical body sized and configured to be received within a passage formed in a talus and a calcaneus, the talo-calcaneal stem having a length sufficient to extend from a top of the talus into the calcaneus, and
a convex dome configured to be coupled to the talo-calcaneal stem and articulate with the concave dome.
7. The ankle implant of claim 6 , wherein the lower prosthesis further includes a tray sized and configured to be attached to a planar surface formed on the top of the talus.
8. The ankle implant of claim 7 , further comprising an overhang extending from the tray such that the overhang overlaps at least a portion of the calcaneus.
9. The ankle implant of claim 6 , wherein an end of the talo-calcaneal stem includes a Morse taper for coupling with the convex dome.
10. A prosthesis, comprising:
a tibial stem having a cylindrical body sized and configured to be received within a tibia, the tibial stem defining at least one opening extending through a width of the tibial stem;
a concave dome sized and configured to be coupled to an end of the tibial stem;
at least one securing member extending through the at least one opening of the tibial stem;
a plate having a first portion configured to be coupled to a planar surface formed on a top of a talus, an overhang portion extending from the first portion at an angle and having a length sufficient to extend from the top of the talus and overlap a portion of a calcaneus when the first portion of the plate is coupled to the planar surface formed on the talus;
a talo-calcaneal stem having a length sufficient to extend from the top of the talus into the calcaneus; and
a convex dome sized and configured to be coupled to an end of the talo-calcaneal stem and to articulate with the concave dome.