Anterior fusion for rotationally unstable cervical spine fractures

Abstract

Study design: A retrospective analysis of 32 rotationally unstable cervical fractures treated by brace, halo vest, or posterior surgical constructs plus fusion is compared with a second, prospective study of 18 similar fractures treated by early anterior discectomy, fusion, and plating.

Objectives: To characterize an often unrecognized fracture pattern and compare various methods of management to identify the most effective treatment.

Summary of background data: The rotationally unstable cervical spine fracture (compression-extension Stage 1) involves a hyperextension and lateral flexion injury, resulting in a unilateral pedicle, facet complex, and/or lamina fracture under compression and anterior annular disruption under tension. This fracture pattern allows a rotatory spondylolisthesis of the spine around the axis of the intact lateral mass and facet complex.

Methods: A retrospective review was made of 284 cervical fractures, identifying 32 compression-extension Stage 1 fractures that were treated by a variety of techniques. The results of that study led to a second (prospective) study, in which 18 similar fractures were treated by early anterior discectomy, fusion, and plating.

Results: Nonoperative treatment was uniformly unsuccessful. Posterior stabilization and fusion procedures led to unsuccessful results in 45%, related either to late kyphosis because of disc collapse or the inability of midline stabilization procedures to control rotational instability. Anterior fusion resulted in solid union without residual deformity in all cases. All four patients in the prospective study with incomplete cord lesions showed improvement in cord function, as did seven patients who had radiculopathy.

Conclusion: Although posterior bony injury is the usual radiographic finding, the anterior disc and anterior longitudinal ligament disruption are the more significant injuries and lead to late collapse and kyphotic deformity. Early anterior fusion is recommended in compression- extension Stage 1 cervical spine injuries.