Patent ID: 8292955

Claim:
A joint implant configured for insertion into a synovial joint of a patient, comprising: an elastic biconcave structure configured to be free-floating within a joint space, comprising: a radiolucent arcuate perimeter region comprising an increased thickness, a first radius of curvature, two end regions with a perimeter gap therebetween, a perimeter protrusion opposite from the gap and protrudes a distance beyond the first radius of curvature, and an elongate radiopaque core, the core comprising a polymer and a radio-opaque material; and a span region comprising a reduced thickness and surrounded by the arcuate region, wherein the span region comprises a substantially concave edge abutting to the gap; wherein the arcuate region and span region together form a generally biconcave structure comprising a first concave surface and a second concave surface located on an opposite surface of the structure and facing a direction opposite of the first concave surface.