Ann Green is a 66-year-old woman who was referred to the rheumatology outpatient clinic by her family physician, Dr. Mac Grad. In his referral note, Dr. Grad states that Mrs. Green has been experiencing joint achiness for the past several years, involving mostly her hands and knees. From time to time, she has also reported low back pain. Her symptoms have always been relatively mild and have never stopped her from carrying on with her general daily activities or her charitable work in the community. What currently concerns Dr. Grad is that Mrs. Green's symptoms have progressed. Usually a rather stoic person, she is now complaining of increased pain in her fingers and both knees. Because of her knee pain, she is having increasing difficulty walking. Whereas previously her pain would always settle after she took some Tylenol, this is no longer the case. On physical examination, Dr. Grad elicits tenderness at several of the proximal (PIP) and distal interphalangeal (DIP) joints of both hands and at the carpometacarpal joint of the left thumb. Heberden's nodes are evident at the DIP joints bilaterally. Tenderness is also present at the joint lines of both knees; and there is (chronic) puffiness on both sides, but more pronounced on the left. Knee flexion is reduced and there is bony crepitus. Radiographs demonstrate osteoarthritic changes at the wrists, the PIP and DIP articulations of the fingers, and moderately severe (tri-compartmental) degenerative changes at both knees.