We report 13 fracture-separations of an articular pillar at the lower
cervical spine in 12 patients. There were 9 men and 3 women with a mean
age at injury of 32 years, with involvement of C4, C5 and C6 vertebrae.
Neurological symptoms were present in 9 patients, 2 were classified as
ASIA A and 7 as ASIA D. The average magnitude of rotation of the
articular pillar was 24 degrees (10 degrees-36 degrees). 4 patients with
neurologic deficit and a rotated articular pillar of more than 25
degrees were operated on, while 8 patients, 3 of which had a rotation of
more than 25 degrees, had closed treatment. Patients were followed from
8 months to 15 years (mean 9 years). Patients who had closed treatment
and/or with a rotated fractured articular pillar of more than 25 degrees
had less satisfactory results. This observation was affirmed by
cadaveric studies which showed that rotation of more than 25 degrees is
an additional factor of instability in a fractured articular pillar
