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.
1 Inside of Knee: Pain on the inside, or medial side, of the knee, is commonly caused by medial meniscus tears, MCL injuries, and arthritis.  Outside of Knee: Pain on the outside of the knee, or lateral side, is commonly caused by lateral meniscus tears, LCL injuries, IT band tendonitis, and arthritis.