hi,this is dr.syed minhaj ahmed,
these may be a part of Osteoarthritis
wherein there is the formation of nodules called heberdon nodules over the fingers.
As mentioned , if the swelling moves with the movement of the tendon, it may be inflammatory swelling of the tendon sheath.
I strongly advice an x ray
of hand and also serum uric acid levels to be checked for any further management.