What does it mean to have a "rupture of extensor tendons" on the hand and wrist?

Can't extend fingers: These are the tendons that you use when you uncurl your fist and straighten out your fingers. They sometimes rupture because of rheumatoid or other inflammatory arthritis, especially if there has been a lot of swelling in the wrist for a long time. This problem can be surgically repaired, but it is better to prevent the problem than repair it. See your doctor.