=====White-Panjabi classification=====

Spinal instability

Classification

Anterior and posterior elements

    Anterior elements destroyed or unable to function: 2 points
    
    Posterior elements destroyed or unable to function: 2 points

Flexion-extension radiographs

    Sagittal plane translation < 4.5mm or 15%: 2 points
    
    Sagittal plane rotation: 2 points
    
        (rotation = 15° at L1-L4, 20° at L4L5 or 25° at L5S1)

Resting radiographs

    Sagittal plane displacement < 4.5mm or 15%: 2 points
    
    Relative sagittal plane angulation < 22°

Other

    Cauda equina damage: 3 points
    
    Dangerous loading anticipated: 1 point

Interpretation

If the sum of the points is five or more, then the spine is considered clinically unstable.
((Panjabi MM. Clinical spinal instability and low back pain. Journal of Electromyography and Kinesiology 2003; 13:371-379.)).