People who underwent orthopedic or spinal surgery during a period of time at Denver's Porter Adventist Hospital could be at risk for hepatitis B and C, as well as HIV. That's due to an inadequate sterilization which may have compromised instruments. Health officials say the breach of procedure happened from July 21st of 2016 to February 20th of this year. Letters were recently mailed out to patients who may be at risk. So far, health officials are not aware of any infections. They also consider the risk factor of contracting the illnesses through surgery to be low.