Osteoarthritis?

A second visit to the GP to discuss my Baker's cyst and a chronic stiffness in the first two fingers of my left hand.  He talked about getting the cyst drained and the possibility of surgery but also commented that the cyst was probably the symptom of another problem and likely to return unless the underlying cause was alleviated.
And the fingers?  Some residual inflammation from an earlier knock.
And the stiff knees?  Possibly the onset of osteoarthritis, given the wear and tear of cycling.  My GP suggested further investigation: blood tests for markers of rheumatoid arthritis and an X-ray to check for bone erosion and anomalous geometry of the joint.  We agreed that it was best to monitor the cyst but do nothing for the time being.