Post-motor vehicle accident alar ligament laxity

The alar ligaments play an integral role in stabilization of the craniovertebral region. They need to be evaluated clinically and radiologically, with specific tests to stress them, in patients who have sustained trauma to their craniovertebral region. Historically, their integrity has not been addressed. The purpose of this paper is to direct the attention of the physical therapist to the craniovertebral region in patients involved in motor vehicle accidents. To demonstrate the relationship between the clinical test for alar ligament laxity and functional side flexion X-rays of the upper cervical spine, the biomechanics of the alar ligaments and their relationship to the appropriate stress X-rays are reviewed. A case presentation is made of a patient whose radiological findings supported the clinical findings of right alar ligament laxity. It is postulated that the force generated by a motor vehicle accident can cause an isolated injury to the alar ligaments, particularly if the head is positioned in flexion and rotation. Physical therapists need to be aware of the possibility of this injury in motor vehicle accident patients. Therefore, it is recommended that functional side flexion X-rays of the upper cervical spine be included along with flexion-extension stress X-rays. This would assist in the diagnosis of alar ligament problems in the motor vehicle accident patient population where the head was in rotation or side bend when the accident occurred. Further research into diagnostic imaging of the craniovertebral region is warranted. J Orthop Sports Phys Ther 1992;16(1):6-11.