Atlantoaxial fusion is a surgical procedure that involves the fusion of the atlas (C1 vertebra) and axis (C2 vertebra) bones of the neck. This procedure is done to stabilize the atlantoaxial joint, which is responsible for the majority of rotation of the head.

There are many reasons why a patient may need an atlantoaxial fusion. Some common reasons include congenital abnormalities, rheumatoid arthritis, and trauma to the neck. Patients who have these conditions may experience instability of the atlantoaxial joint, which can result in spinal cord compression or damage.

The surgical procedure involves the placement of screws and rods into the atlas and axis bones to hold them together and promote fusion. This fusion can take several months to complete, during which time the patient may need to wear a cervical collar to immobilize the neck.

In conclusion, atlantoaxial fusion is a surgical procedure that is used to stabilize the atlantoaxial joint in patients with certain medical conditions. While there are risks associated with the procedure, it can be highly effective in preventing spinal cord compression and damage.