Patent ID: 8460390

Claim:
A trial implant for a joint of a patient, comprising: a stem component configured for placement within a bone of a patient; an articulating component configured for articulating contact with a mating aspect of the joint; and a mounting assembly for mounting the articulating component to the stem component at variable angular orientations relative thereto, including; a cavity defined in the stem component; a mounting element having a portion configured to support the articulating component and an expandable portion configured to expand within said cavity; and an expansion element rotatable within said mounting element and cooperating with said expandable portion upon rotation to expand said expandable portion within said cavity; wherein said expandable portion of said mounting element includes an expanding ball, and a bore within said ball; wherein mating portions of said expansion element and said bore define a rotational engagement so that rotation of said expansion element drives said expansion element into said bore; wherein said expansion element and said bore include cooperating portions that cooperate to expand said ball when said expansion element is driven into said bore; and wherein said expanding ball includes a first ball portion adjacent said portion of said mounting element configured to support the articulating component and defining a first spherical diameter, and a second ball portion defining a second spherical diameter smaller than said first spherical diameter.