US Constitution the words slave or slavery do not appear in the constitution yet they are certainly referred to it.   1. The 3/5 clause which says that an enslaved person will only count as 3/5 of a person in the census. 2. ban on middle passage slave trade.
Medial compartment arthritis (usually osteoarthiritis) can cause pain on the inner side of the knee. This is usually more of an ache than a sharp catching pain and is present when you walk on the leg. As the arthritis worsens the pain can become continuous and interfere with sleep.
Hard to say: Typically osteoarthritis in the knee causes pain limited to the knee itself and not really the whole leg. It may just be a referred pain for the knee or you may have something else causing pain in the leg in addition to your osteoarthritis.