TFCC stands for triangular fibrocartilage complex and describes a cartilage pad that rests where the ulna bone of the forearm meets the "pinky" side of the wrist.
The name this injury gets depends on which part of the cartilage has been damaged. Class 1A refers to tears right in the middle. Class 1B tells the surgeon that the ligament has torn away from the end of the ulna bone in the forearm. Classes 1C and 1D identify two other places where this tough, fibrous material has been torn.
There are additional ways to classify or name this particular injury. When the damage occurs as a result of degenerative changes from aging, both the location and the severity are named. These names may not mean much to patients, but they are important for doctors when surgery is required.