Rotatory subluxation of the cervical spine — when is odontoid lateral mass asymmetry benign?

Conclusion

Rotatory subluxation of the cervical spine is a rare but serious condition in the adult. The condition is suspected radiologically in the presence of odontoid-lateral mass asymmetry on open mouth view. The application of ATLS principles in the initial assessment of trauma patients has resulted in a significant increase in the number of radiological examinations performed. This has led inevitably to an increase in the number of anomalies identified. An average of 400 cervical spine X-rays per year are performed for trauma in our casualty department.

In this study, we have identified nine patients out of a total of 28 with congenital odontoid-lateral mass asymmetry over a three-year period. This represents approximately 0.75 of the cervical spine X-rays and should be considered in the differential diagnosis following acute cervical trauma.