A partial ankle prosthesis includes a tibial component including a superior surface configured to be attached to a lower end of a patient's tibia; a poly component that is fixedly attached to the tibial component and includes a concave inferior surface of an anti-friction material; and a talar component including an inferior surface configured to be attached to a patient's talus and a single convex superior surface configured to mate with the inferior surface of the poly component; and the partial ankle prosthesis is configured to be implanted in a single compartment of a patient's ankle.