India, Dec. 21 -- When a man visited the doctors complaining of knee pain after falling on his buttocks, he never imagined that the investigation by the medical experts would bring him face-to-face with a rare condition he was suffering from. As it turned out, doctors discovered that his penis was "turning into bone" - a condition known as penile ossification.

According to the National Institutes of Health (NIH), "penile ossification often presents as a painless hard mass on the penile shaft." The organisation further stated that the condition is associated with "Peyronie's disease, trauma, gout and other metabolic disorders."

Reportedly, it is caused when there is a calcium buildup in the soft tissue of the penis. It further leads to a...