Arthrodesis refers to orthopedic surgery in which two or more bones in a joint are fused to become one larger bone. In this process, any diseased cartilage between the two bones is removed, the bone ends are cut off, and the two bone ends are connected to one another using metal internal fixation, such as screws and plates. The two bones eventually grow into one another, fusing to become one. After this, there is no further motion in the joint, but it is stabilized and, most importantly, pain caused by arthritis or instability is eliminated.

The most common parts of the body in which fusion is performed is of spinal vertebrae or bones of the foot or ankle.