This was a retrospective prevalence study.

A review of structural cervical spine injuries (fracture or dislocation) treated at a regional spine injury referral center from 1987 to 1992 was undertaken to identify and analyze patients who had secondary neurologic deterioration after they had arrived and had primary assessment in stable neurologic condition (intact or compromised, but not evolving).

Multiple case reports and cohort studies have suggested possible risk factors for late neurologic deterioration without probabilities analysis.

Information was obtained retrospectively from clinical records and radiographs. Three-hundred-twelve cases were reviewed. Thirty-one were excluded and 281 were analyzed.

An index group of 15 patients (5%) had motor neurologic deterioration after primary assessment at the referral center. Control group "A" was composed of 70 patients (25%) who had a motor neurologic deficit on admission and did not deteriorate. Control group "B" was the balance of 196 patients (70%) with structural cervical injuries, but no neurologic compromise. Factors distinguishing the index group from control subjects included flexural mechanism of injury and chronic multilevel spinal arthritis with ankylosis. All secondary deteriorations occurred with the injury level caudad to the fourth cervical vertebra. Routine three-view cervical radiographs were relatively insensitive in detecting injury in the index group compared with the pooled control subjects. Patients' ability to comply with recommended treatment was not a factor in secondary deteriorations and there generally was no identifiable precipitant event before secondary deterioration.

Cervical traumatized patients with flexural injury or chronic multilevel spinal arthritis with ankylosis are at increased risk of having secondary motor neurologic deterioration.