Patent ID: 8029566

Claim:
An orthopedic implant for placement in a cavity formed in a bone, said cavity having a predetermined shape, said orthopedic implant comprising: a flexible body having an opening, said flexible body having an inflated state wherein said body has an outer shape generally corresponding to said predetermined shape formed in said bone and a non-inflated shape wherein said outer shape has a smaller envelope than said inflated state; a plurality of sensors supported by said flexible body, said plurality of sensors providing an indication of whether said flexible body is in said inflated state or said non-inflated state, wherein said plurality of sensors are configured to detect a presence of a fold in said flexible body, wherein said fold is detected based on said relative position of a first sensor to a second sensor, wherein said first sensor and said second sensor are passive sensors interrogated by an external device, wherein said first sensor and said second sensor are each resonant circuits which provide said indication based on a separation between said first sensor and said second sensor, and wherein when said first sensor and said second sensor are spaced a first distance apart said first sensor resonates in response to a first frequency from said external device and said second sensor resonates in response to a second frequency from said external device and when said first sensor and said second sensor are spaced less than said first distance apart said first sensor and said second sensor resonate together in response to a third frequency from said external device; and a filler, said filler being positioned in said flexible body and causing said flexible body to transition from said non-inflated state to said inflated state.