Segmental lumbar spine instability at flexion-extension radiography can be predicted by conventional radiography.

Pitkanen MT et al. Clin Radiol Jul;57(7). 2002

An interesting study to identify plain radiographic findings that predict segmental lumbar ‘instability’ as proven via flexion-extension radiography. The ‘instability’ was classified into either anterior or posterior “sliding”.The authors noted: “sliding instability is strongly associated with various plain radiographic findings. In mechanical back pain, functional F/E radiographs should be limited. These findings were strongest for degenerative spondylolisthesis and spondolytic spondylolisthesis. Retrolisthesis, traction “spur” and spondyloarthrosis were all statistically significant with slightly lower odds ratios.

Of course a relatively in depth examination with ‘Form/Force’ closure tests and shear instability checks will give us heightened awareness as to the instability issues in many cases even if radiographs are unavailable. Clearly extensive degeneration, though not linearly related to severity or even frequency of cLBP does clearly play a moderately large role in pain.