Argentina's Juan Martin Del Potro recieves attention to his knee after falling at the 2013 Wimbledon Championships tennis tournament
The pill most often prescribed for knee pain - acetaminophen - may not help at all, researchers reported Monday.
The new study of what works for arthritis pain in the knee came up with some surprising results. The most common treatments often may not help much, and even a placebo injection of salt water provides more pain relief than any pill.
