Sidebending versus flexion-extension radiographs in lumbar spinal instability

Area of Science:

• Radiology
• Orthopedics
• Spinal Imaging

Background:

• Lumbar spinal instability diagnosis often relies on flexion-extension radiography.
• The diagnostic utility of sidebending radiography for lumbar instability remains less established.

Purpose of the Study:

• To evaluate the diagnostic contribution of sidebending radiographs compared to flexion-extension views in patients with suspected lumbar spinal instability.

Main Methods:

• Retrospective analysis of flexion-extension and sidebending radiographs from 300 patients.
• Application of established criteria for lumbar spine instability assessment.

Main Results:

• Flexion-extension and sidebending films showed a statistically significant relationship in diagnosing instability, but with poor intertechnique agreement.
• Flexion-extension films identified instability in 84 patients, while sidebending films identified it in 50 patients.
• Sidebending film findings correlated best with angular motion and posterior sliding instability on flexion-extension films.

Conclusions:

• Sidebending radiography can be a complementary tool to flexion-extension radiography for diagnosing lumbar spinal instability.
• Routine use of sidebending films is unlikely to be beneficial due to limited added value.
• Flexion-extension radiography remains the primary imaging modality for assessing lumbar instability.