You order some lab tests

You ask the patient if she has pain at a specific moment of the day or night. She tells you she has some pain getting up after sitting for a while. But the pain is better when she rests and becomes worse after walking for 10 minutes. During the night her knee might wake her up if she is sleeping on her left side. The pain makes her nights difficult. 

You think that this sounds like pain from arthritis. Even though she is not that old, she still has a family history (with her uncle's gout history) so you decide to order some lab tests and x-ray of the knee. 

The duration of the pain, given that it's constant and it's not recurrent, makes you think you have to refer her for further differential diagnosis to a rheumatologist and later on maybe to an orthopedic surgeon if necessary.

You have to see what the rheumatologist has to say first. 

You arrange with your patient a follow up visit to discuss the lab results, the course of treatment and what was discussed with the rheumatologist.