A prosthetic component suitable for long-term implantation is provided. The prosthetic component includes electronic circuitry and sensors to measure a parameter of the muscular-skeletal system. The prosthetic component comprises a first structure having at least one support surface, a second structure having at least one feature configured to couple to bone, and at least one sensor. The electronic circuitry and sensors are hermetically sealed within the prosthetic component. One or more sensors can be used to monitor synovial fluid in proximity to the joint to determine joint health. The prosthetic component includes a transmissive region. One or more optical sensors are mounted in proximity to the transmissive region. Periodic measurements of the synovial fluid are measured through the transmissive region. The measurements can include color and turbidity of the synovial fluid. The color and turbidity data can be compared against known data to determine joint status.
