Figure 1.

Interspinous distance measurement. (A) Sagittal multiplanar reformat (MPR) from multidetector computed tomography (MDCT). The gap between the spinous processes is measured. A 14 mm interspinous widening is consistent with posterior ligamentous complex (PLC) tear. (B) interspinous distance is measured in AP radiographs by measuring the distance between the upper borders of the spinous processes projection of contiguous vertebrae. Percentage of widening of the interspinous distance can be calculated with the following formula, where A is the interspinous distance of the normal superior vertebra, B is the interspinous distance at the fractured vertebra and C is the interspinous distance of the normal inferior vertebra: $\%ofwidening=\frac{\left(B-\frac{(A+C)}{2}\right)}{\frac{(A+C)}{2}}\times 100$. (C) Sagittal MPR in MDCT shows 7 mm interspinous widening suspicious of PCL tear that was ruled out by MRI (arrow in D).