Role of facet asymmetry in lumbar spine disorders.

The correlation between facet joint asymmetry and disorders of the lumbar spine was analyzed in a study of plain radiographs, computed tomograms and magnetic resonance images from 76 normal subjects and 173 patients who underwent lumbar surgery. Of 76 normal controls who were studied by means of plain radiographs, only 21 (27.6%) had facet asymmetry at the level of L4-5 or L5-S1, while 84 (48.6%) of 173 patients who were studied with plain radiographs, and partially with CT or MRI, were noted to have facet asymmetry. The difference was highly significant (P < 0.01). This study supports the etiologic significance of facet asymmetry in lumbar disorders.