Connective Tissue Disorder
Some connective tissue disorders would damage the lining of knee joints. They trigger the immune system to attack those cells rather than harmful components. As a result, it leads to painful swelling that would cause bone erosion or joint deformity if left untreated. In addition to occurring in your knee, the condition would also spread to other body parts. There is still no cure for connective tissue disorders, but many treatments and drug options are currently available. These might include DMARDs, biological agents, corticosteroids, or NSAIDs. [3]
