Which test assesses for AA instability due to a disruption of the transverse ligament?

The Sharp Purser Test is specifically designed to assess for atlanto-axial (AA) instability, particularly due to disruption of the transverse ligament. This ligament plays a crucial role in stabilizing the connection between the first and second cervical vertebrae (C1 and C2), and any compromise can lead to instability, which can be dangerous.

During the Sharp Purser Test, the examiner stabilizes the occiput and applies a posterior force to the forehead while assessing for the movement of the atlas relative to the axis. If the test is positive, it indicates that there is excessive translation of C1 on C2, suggesting instability.

This test is particularly relevant in cases where there may be concerns over ligamentous integrity, such as in patients with rheumatoid arthritis or trauma, making it a vital assessment tool in evaluating the integrity of the cervical spine.

The other assessments listed focus on different structures or conditions. The Alar Ligament Stress Test evaluates the integrity of the alar ligaments, which help stabilize the upper cervical spine and maintain rotation. The Transverse Ligament Stress Test also assesses for transverse ligament integrity but does not specifically assess for AA instability through a translational movement like the Sharp Purser Test. The Vertebral Artery Test