What is medical term for condition of joined fingers or toes?

The joints at the base of the fingers are called metacarpal phalangeal joints (MPJ's) and form knuckles when you make a fist. These are elliposoidal joints. The ones that are in the fingers themselves are called interphalangeal joints. The thumb only has one called a proximal interphalangeal joint (PIP) and the other four fingers each have two. The first one is called the proximal interphalangeal joint (PIP)and the last one is the distal interphalangeal joint (DIP. These are all hinge joints.