What are some effective treatments for osteoarthritis?

DEAR DOCTOR K: I have osteoarthritis of my hands. Are any treatments particularly effective for this condition?
DEAR READER: Osteoarthritis causes stiffness and pain in the joints. It develops when cartilage -- the tissue that covers the ends of bones -- deteriorates. In the hand, osteoarthritis usually strikes the joint at the base of the thumb and the last joints before the tip of the fingers.