Before we discuss your procedure, it is important for you to understand the normal anatomy of the wrist.
The wrist is made up of eight small bones, called "carpal" bones. The carpal bones connect the bones in your forearm to the bones in your hand. These are held together by ligaments. The median nerve, which controls some of your hand muscles and allows you to feel sensations with your hand, passes from the forearm to the hand through a confined space in the wrist called the "carpal tunnel." It is much like a tunnel you drive your car through, having a ceiling, floor, walls, an entrance, and exit. The carpal ligament is the tough "ceiling" of the carpal tunnel.
Several tendons also pass through this tunnel. Each one has a special slippery covering, called the "synovium," which allows the tendons to glide smoothly as you move your fingers. In a normal wrist, there is adequate room for both the tendons and the nerve.