Functional diagnostics of the cervical spine using computer tomography.

35 healthy adults and 137 patients after cervical spine injury were examined by functional CT. The range of axial rotation at the level occiput/atlas, atlas/axis and the segment below were measured in all subjects. A rotation occiput/atlas of more than 7 degrees, and C1/C2 more than 54 degrees could indicate segmental hypermobility, a rotation at the segment C1/C2 less than 29 degrees to hypomobility. According to the postulated normal values based upon a 98% confidence level, out of 137 patients examined after cervical spine injury and with therapy-resistant neck pain, 45 showed signs of segmental hypermobility of the upper cervical spine, 17 showed hyper- or hypomobility at different levels, 10 patients presented segmental hypomobility at C1/C2 level alone. In all patients, according to the clinical assessment, functional pathology was suspected in the upper cervical spine. Surgical correction of rotary instability should be considered as a possible therapeutic procedure after successful diagnostic stabilisation of the cervical spine by minerva cast.