1. The treatment is described of a consecutive series of fourteen patients suffering from rheumatoid arthritis causing a slip of the cervical vertebrae, mainly at the C.1-2 level, and a cord lesion.

2. The importance of a change of symptoms and signs in these patients, especially the occurrence of the so-called "alarm signs", is stressed.

3. In twelve patients the combination of this kind of cervical instability with a cord lesion was treated by fusion, most frequently of occiput to C.2 and 3.

4. In the eleven patients who survived the operation the results with a follow-up period of one to eight years are considered highly gratifying.

5. Technical details and various problems associated with treatment are discussed.