A prosthetic disc can take the form of a sensing artificial disc that includes a resilient core and at least one sensor configured to sense one or more conditions within and/or experienced by the disc. The sensing artificial disc can serve as a replacement to a failed or injured disc between two vertebrae of a spine. The sensing artificial disc can include at least one element configured to change a condition or property of the resilient core in response to a condition sensed by the at least one sensor. A prosthetic disc can include therapeutic system configured to deliver medication to the body, which can include a reservoir of medication.