Implantable sensors are described that can be utilized in conjunction with orthopedic implants for monitoring fracture healing and detecting local chemical concentrations to detect and monitor implant associated infection. The sensors can include strain gauges, electrochemical, or spectrochemical sensors that can be read transdermally using a single photodetector. Sensors can be affixed to implantable support devices so as to non-invasively monitor the effect of load on the implant to provide a quantitative assessment of when a fracture is sufficiently healed to allow safe weight-bearing upon the limb. Alternatively, sensors can monitor the local concentration of infection biomarkers, for instance to monitor the implant area for early stage infection.
