What does it mean if you have swollen lymph nodes and joint pain?

Infection likely. Lymph node involvement indicates an immune response; usually the presence of an infection. Some infections can enter a joint space, causing pain and swelling, heat and redness.
See your doc. Swollen lymph nodes associated with joint pain can be due to an infection, immune system disorder (such as rheumatoid arthritis) see your doctor for a physical exam as well as various lab/blood test to evaluate further and rule out other serious diseases.