Apparatus and methods for using an electromagnetic transponder in orthopedic procedures

A system for tracking a prosthesis implanted in a human, the system comprising:

• a spinal stabilization device configured to be received in a cavity of the human, wherein the spinal stabilization device includes an inflatable body sized and shaped to be positioned between spinous processes of adjacent superior and inferior vertebrae when the spinal stabilization device is in an expanded state, and wherein the inflatable body includes an aperture through a wall of the inflatable body;
• a magnetic transponder positioned in the aperture of the inflatable body of the spinal stabilization device, wherein a first outer surface of the magnetic transponder protrudes radially from an exterior surface of the inflatable body in a first general direction and defines an exterior outer portion of the spinal stabilization device, wherein a second outer surface of the magnetic transponder protrudes radially from an interior surface of the inflatable body in a second general direction opposite the first general direction and defines an interior portion of the spinal stabilization device, and wherein the transponder has a circuit configured to be energized by a wirelessly transmitted pulsed magnetic field and to wirelessly transmit a pulsed magnetic location signal in response to the pulsed magnetic field;
• and
• a sensor assembly comprising a support member and a plurality of field sensors carried by the support member configured to sense the pulsed magnetic location signal from the transponder.