There are few diseases, situations where a fixation of the head to the cervical spine is necessary. This is the case when the head and neck joints are changed as a result of accidents, inflammation or tumor which again will result in instability, and it comes to pain but also neurological deficits. These can be disturbances of feelings, gait disturbances and paralysis.
The head joint is very important. A stiffening in the joints leads to a significant restriction of movement, especially in the head flexion and rotation. A patient with a stiffness in this joint moves as if he/she had a stick in the neck. It is out a so-called "en bloc" movement of the cervical spine, nodding is not possible. The fixation is done in a neutral position. This means that movement restrictions can be compensated by eye movements. There is a strict indication of when such an operation must be carried out.
A typical indication is the so-called basilar invagination, which is when the cervical spine, especially the dens axis is partly shifted into the head by the spinal canal and therefore damages the brain stem. This can occur in rheumatoid arthritis.
Rheumatic disorders can cause a wide range destruction of the head and neck area. The most common ones concern the dens (i.e. the second cervical vertebrae). It may change greatly inflammatory and may therefore constrict the spinal canal. Previously thisinflamed pannus was removed through the mouth (transoral). Today we know that a stabilization operation is sufficient to ensure the involution. Often a C1-C2 stabilization is enough. Sometimes, however, the occiput has to be involved.